Vampire

Vampire... are fascinating creatures - scary but fascinating. His form is like human but more charming with his elegance attitude and beauties looks. Like Panther and the another beast, looks so elegance and beautiful but so deadly. He can lure his victim to his trapt with his beauties appearence. In order to survive, he suck his victims blood. Believing, blood is contains the source of life. With taken the blood from his victim, he can drain 'a life' to his own body to continue life. Many assumption that vampire has an eternal life. Its not exactly true. Vampire just have a long life than human with an eternal young. He has never seen old even his age has reached a hundreds of years. But vampire can die if we stake him through to the heart. Staking a vampire through the heart is supposed to cut off his lifeforce or weaken him and with other methods such as break his head can kill him completelly.


Between Vampire and Dracula

People always been make the same perception between Vampire and dracula. It's a wrong assumption . Vampire is different race with human but dracula is from human race. Dracula is mean dragon from Rumania language (Dracul). Dracula is a true story from the history. He is a prince from Wallachia (Rumania). His name is Vlad III or Vladimir Tapes. Dracula itself means a dragon boy (Drac= dragon. Ull=boy), He has acquired this earl title because his father affiliation with Dragon Order in his period.Dracula has been reputed as vampire because of his cruelness to everyone during pra and pasca war period with Ottonam Sultanate which is his own step father at once as father in law (even his wife-Ottonam daugter- was been killed by him too). Impalament was Ţepeş's preferred method of torture and execution his foe or friend, his own citizens that guilty in his opinion, even woman and babies will be killed by him with impale methods. His cruel intensity beyond from humanity. So that why people always considered him as the demon. But, with his dictator regime was successes to control his people in peace behind the fear in his territorial. Even more, Bram Stroker who make the famous novel "Dracula" based on Vladimir history, and of course he put a 'little' changed into Vladimir or Dracula 's identity as a vampire in his novel. That why people always considered a man who name Dracul is a vampire.

History of  Vampire

The history of the origins Vampire itself was not known from the truth. But have spreads fours version about it1. From the myth of Adam and Lilith son

In the myth, Eve is not an Adam first wife. The first woman has been created by God is Lilith. However, Lilith never want bow down upon Adam. She thinks Adam is same with her. A human. So why must Adam have being chosen by the God becomes leader for her? Did they are come from the same race? So she deny to admit Adam become her leader because she think she have a same opportunity as if Adam was. Because her arrogances and rebel from God command to admit Adam as her leader, Lilith became a damned creature and driven from the heaven. This is makes her a first female demon. After she driven away from the heaven, Lilith make association with Lucifer, the first Demon (as known as the fallen Angel cause his rebelling God command, same like Lilith does). Before that Lilith has one son with Adam, his name was Caine. After Lilith became a damned, God create Eve to replace Lilith as Adam's wife.When Adam and Eve break the God prohibition, they punished out from heaven and lived on earth. When Lilith knows what happening with Adam, she flew to see her son, Caine. When she meets Caine, she explains to Caine that she is Caine's true mother. Caine ask her to turn him became demon likes his mother was. So he can live forever with his mother forever. Initially, Eve refusing his son wishes. Cause just God have such the power to turn someone into damned completely like her and Lucifer was. She doesn't have that enormous power like God did. But Caine have his own speculating, if his mother become a damned so the blood that flow in her veins also be damned too. If he drink his mother blood that means he can change being one of damned like his mother Again, his mother not agreed with those methods. Because, no one ever been have tasted the damned's bloods. Especially for human. A weak human body absolutely will not strong enough to hold on of her powers. She afraid his son will die. But Caine still insist. Because Lilith loves her son very much, finally she grants what is Caine wishes. She took Caine mortal blood and replace it with her cursed blood instead.But just like as she has prediction before she dont have an enormous power like God to changes Caine completely. Caine was dead but then he rise again from his death. Now he is not a mortal nor an immortal like her mother. But in the middle of that kind. Caine was being undead. A filthy creature that will life without soul. He will never aging and have a long lasting life than human does but not immortal as Lilith and lucifer was. That undead was called a vampire. But for exchange his unaging and long lasting life, forever in his lifetime he must suck people life through the blood. In order to fill his empty soul in his body to keep his body alive and unaging. But for exchange his eternal youth and long lasting life, forever in his life he must take the source of life from living creatures through the blood in order to keep his own life. And live forever in the darkness far away from the sun2. From Cain's Myth story

Adam has some a son and daughter with Eve. One of son is Cain (Kabil) and Habil (Qabil). As we know the murderer by Cain to his little brother, Habel. Because what he deeds, God was cursed him into darkness creature.3. From Judas Myth story

Judas is one of 12 Jesus or Isa Al-masih students. Since Judas betray Jesus for 30 pieces of silver, for his howler when Judas died, at the time birth of new devil that weak with silver.4. From Akasha myth story

According from legend, Akasha is one of legendary queen from the ancient Egypt. She has beautiful face yet cruel. She is obsession with the eternal youth and life secrets. Then she captures a young twins girls which is the great oracle that able to communicate with the spirits. The spirits sure have known about the secret of the eternal youth and life. However, the twin oracle resists her command because they sense some evil intention from Akasha. The anger Akasha tortures the twin oracle because they don't want to granted her obsession. One of ancient evil spirits who has make promise with the twin oracles's mother, so anger with Akasha have done to the oracle's. Then that ancient evil spirit obsesess Akasha. Because Akasha body is not able to accommodate the power of the ancient evil spirits, slowly but sure starting consume her soul, and turn her being a darkness creatureThe first person that she infected was her king. Then she infected some noble man and woman. in her kingdom. The two oracle girl can't slipped away from her infection too. Not long after the two oracle became a vampire, they succeed run awal from Akasha castle. For the beginning, Akasha can control her vampire creations. But they come morely aggressive, even Akasha and her kings become they adorer prisoner. They blood was been sucked and share it for they followers but of course still kept Akasha and her king alive. They believe, with drink the queen of the vampire's -the origins vampir-blood will increase their power. Akasha cursed and threaten them, if she can release herself she will suicide with burn by the sun light. She is the source of vampire, if the source dies then every vampire dies too. and the vampire who has drank her blood will burn along with her.All the vampire fear to hear Akasha's threats then they really keeping her in order Akasha not kill himself with burn herself to the sunlight. Because she can't release herself, then Akasha finally decided to "silent", with its king. In process of time he turn into the a statue with her king and sat waiting for the right time to wake up and get her revenge. Until they were freed by their loyal guards, they are silent, such as sculptures, and remain 'sleep' so for thousands of years

Capacitor

A capacitor is a passive electronic component that storesenergy in theform of an electrostatic field. In its simplest form, a capacitorconsists of twoconducting plates separated by an insulating material called thedielectric. Thecapacitance is directly proportional to the surface areas of the plates, andis inverselyproportional to the separation between the plates. Capacitance alsodepends on thedielectric constant of the substance separating the plates.

The standard unit of capacitance is the farad, abbreviatedF. Thisis a large unit; more common units are the microfarad, abbreviated µF (1 µF =10^-6F) and the picofarad, abbreviated pF (1 pF = 10^-12 F).

Capacitors can be fabricated onto integrated circuit (IC)chips. They are commonly used in conjunction with transistors in dynamic random access memory (DRAM). The capacitors helpmaintain thecontents of memory. Because of their tiny physical size, thesecomponents have lowcapacitance. They must be recharged thousands of times per second or theDRAM willlose its data.

Large capacitors are used in the power supplies of electronicequipment ofall types, including computers and their peripherals. In these systems,thecapacitors smooth out the rectified utility AC, providing pure, battery-likeDC.

HOW CAPACITOR WORKS??? 

In a way, a capacitor is a little like a battery. Although they work in completely different ways, capacitors and batteries both store electrical energy. If you have read How Batteries Work, then you know that a battery has two terminals. Inside the battery, chemical reactions produce electrons on one terminal and absorb electrons on the other terminal. A capacitor is much simpler than a battery, as it can't produce new electrons -- it only stores them.

In this article, we'll learn exactly what a capacitor is, what it does and how it's used in electronics. We'll also look at the history of the capacitor and how several people helped shape its progress.

Inside the capacitor, the terminals connect to two metal plates separated by a non-conducting substance, or dielectric. You can easily make a capacitor from two pieces of aluminum foil and a piece of paper. It won't be a particularly good capacitor in terms of its storage capacity, but it will work.

theory, the dielectric can be any non-conductive substance. However, for practical applications, specific materials are used that best suit the capacitor's function. Mica, ceramic, cellulose, porcelain, Mylar, Teflon and even air are some of the non-conductive materials used. The dielectric dictates what kind of capacitor it is and for what it is best suited. Depending on the size and type of dielectric, some capacitors are better for high frequency uses, while some are better for high voltage applications. Capacitors can be manufactured to serve any purpose, from the smallest plastic capacitor in your calculator, to an ultra capacitor that can power a commuter bus. NASA uses glass capacitors to help wake up the space shuttle's circuitry and help deploy space probes. Here are some of the various types of capacitors and how they are used.

• Air - Often used in radio tuning circuits
• Mylar - Most commonly used for timer circuits like clocks, alarms and counters
• Glass - Good for high voltage applications
• Ceramic - Used for high frequency purposes like antennas, X-ray and MRI machines
• Super capacitor - Powers electric and hybrid cars 
   
  In an electronic circuit, a capacitor is shown like this: (Uploaded soon)
  When you connect a capacitor to a battery, here's what happens: (Uploaded soon)
   

  • The plate on the capacitor that attaches to the negative terminal of the battery accepts electrons that the battery is producing.
  • The plate on the capacitor that attaches to the positive terminal of the battery loses electrons to the battery.

  Once it's charged, the capacitor has the same voltage as the battery (1.5 volts on the battery means 1.5 volts on the capacitor). For a small capacitor, the capacity is small. But large capacitors can hold quite a bit of charge. You can find capacitors as big as soda cans that hold enough charge to light a flashlight bulb for a minute or more.
  Even nature shows the capacitor at work in the form of lightning. One plate is the cloud, the other plate is the ground and the lightning is the charge releasing between these two "plates." Obviously, in a capacitor that large, you can hold a huge amount of charge!
  Let's say you hook up a capacitor like this: (Uploaded soon)
  Here you have a battery, a light bulb and a capacitor. If the capacitor is pretty big, what you will notice is that, when you connect the battery, the light bulb will light up as current flows from the battery to the capacitor to charge it up. The bulb will get progressively dimmer and finally go out once the capacitor reaches its capacity. If you then remove the battery and replace it with a wire, current will flow from one plate of the capacitor to the other. The bulb will light initially and then dim as the capacitor discharges, until it is completely out.
  
  Like a Water Tower

  One way to visualize the action of a capacitor is to imagine it as a water tower hooked to a pipe. A water tower "stores" water pressure -- when the water system pumps produce more water than a town needs, the excess is stored in the water tower. Then, at times of high demand, the excess water flows out of the tower to keep the pressure up. A capacitor stores electrons in the same way and can then release them later.

   

  A capacitor's storage potential, or capacitance, is measured in units called farads. A 1-farad capacitor can store one coulomb (coo-lomb) of charge at 1 volt. A coulomb is 6.25e18 (6.25 * 10^18, or 6.25 billion billion) electrons. One amp represents a rate of electron flow of 1 coulomb of electrons per second, so a 1-farad capacitor can hold 1 amp-second of electrons at 1 volt.
  A 1-farad capacitor would typically be pretty big. It might be as big as a can of tuna or a 1-liter soda bottle, depending on the voltage it can handle. For this reason, capacitors are typically measured in microfarads (millionths of a farad).
  To get some perspective on how big a farad is, think about this:
  

  • A standard alkaline AA battery holds about 2.8 amp-hours.
  • That means that a AA battery can produce 2.8 amps for an hour at 1.5 volts (about 4.2 watt-hours -- a AA battery can light a 4-watt bulb for a little more than an hour).
  • Let's call it 1 volt to make the math easier. To store one AA battery's energy in a capacitor, you would need 3,600 * 2.8 = 10,080 farads to hold it, because an amp-hour is 3,600 amp-seconds.

  If it takes something the size of a can of tuna to hold a farad, then 10,080 farads is going to take up a LOT more space than a single AA battery! Obviously, it's impractical to use capacitors to store any significant amount of power unless you do it at a high voltage.
  Applications
  The difference between a capacitor and a battery is that a capacitor can dump its entire charge in a tiny fraction of a second, where a battery would take minutes to completely discharge. That's why the electronic flash on a camera uses a capacitor -- the battery charges up the flash's capacitor over several seconds, and then the capacitor dumps the full charge into the flash tube almost instantly. This can make a large, charged capacitor extremely dangerous -- flash units and TVs have warnings about opening them up for this reason. They contain big capacitors that can, potentially, kill you with the charge they contain.
  Capacitors are used in several different ways in electronic circuits:
  

  • Sometimes, capacitors are used to store charge for high-speed use. That's what a flash does. Big lasers use this technique as well to get very bright, instantaneous flashes.
  • Capacitors can also eliminate ripples. If a line carrying DC voltage has ripples or spikes in it, a big capacitor can even out the voltage by absorbing the peaks and filling in the valleys.
  • A capacitor can block DC voltage. If you hook a small capacitor to a battery, then no current will flow between the poles of the battery once the capacitor charges. However, any alternating current (AC) signal flows through a capacitor unimpeded. That's because the capacitor will charge and discharge as the alternating current fluctuates, making it appear that the alternating current is flowing.

  
  
  Capacitive Touch Screens

  One of the more futuristic applications of capacitors is the capacitive touch screen. These are glass screens that have a very thin, transparent metallic coating. A built-in electrode pattern charges the screen so when touched, a current is drawn to the finger and creates a voltage drop. This exact location of the voltage drop is picked up by a controller and transmitted to a computer. These touch screens are commonly found in interactive building directories and more recently in Apple's iPhone.

   

   

  History of Capacitor 

   The invention of the capacitor varies somewhat depending on who you ask. There are records that indicate a German scientist named Ewald Georg von Kleist invented the capacitor in November 1745. Several months later Pieter van Musschenbroek, a Dutch professor at the University of Leyden came up with a very similar device in the form of the Leyden jar, which is typically credited as the first capacitor. Since Kleist didn't have detailed records and notes, nor the notoriety of his Dutch counterpart, he's often overlooked as a contributor to the capacitor's evolution. However, over the years, both have been given equal credit as it was established that their research was independent of each other and merely a scientific coincidence [source: Williams]. The Leyden jar was a very simple device. It consisted of a glass jar, half filled with water and lined inside and out with metal foil. The glass acted as the dielectric, although it was thought for a time that water was the key ingredient. There was usually a metal wire or chain driven through a cork in the top of the jar. The chain was then hooked to something that would deliver a charge, most likely a hand-cranked static generator. Once delivered, the jar would hold two equal but opposite charges in equilibrium until they were connected with a wire, producing a slight spark or shock [source: Williams].
   

   
   

Regulator

A voltage regulator is an electrical regulator designed to automatically maintain a constant voltage level.

It may use an electromechanical mechanism, or passive or active electronic components. Depending on the design, it may be used to regulate one or more AC or DC voltages.

With the exception of passive shunt regulators, all modern electronic voltage regulators operate by comparing the actual output voltage to some internal fixed reference voltage. Any difference is amplified and used to control the regulation element in such a way as to reduce the voltage error. This forms a negative feedback servo control loop; increasing the open-loop gain tends to increase regulation accuracy but reduce stability (avoidance of oscillation, or ringing during step changes). There will also be a trade-off between stability and the speed of the response to changes. If the output voltage is too low (perhaps due to input voltage reducing or load current increasing), the regulation element is commanded, up to a point, to produce a higher output voltage - by dropping less of the input voltage (for linear series regulators and buck switching regulators), or to draw input current for longer periods (boost-type switching regulators); if the output voltage is too high, the regulation element will normally be commanded to produce a lower voltage. However, many regulators have over-current protection, so entirely stop sourcing current (or limit the current in some way) if the output current is too high, and some regulators may also shut down if the input voltage is outside a given range

Measures of regulator quality

The output voltage can only be held roughly constant; the regulation is specified by two measurements:

• load regulation is the change in output voltage for a given change in load current (for example: "typically 15mV, maximum 100mV for load currents between 5mA and 1.4A, at some specified temperature and input voltage").
• line regulation or input regulation is the degree to which output voltage changes with input (supply) voltage changes - as a ratio of output to input change (for example "typically 13mV/V"), or the output voltage change over the entire specified input voltage range (for example "plus or minus 2% for input voltages between 90V and 260V, 50-60Hz").

Other important parameters are:

• Temperature coefficient of the output voltage is the change in output voltage with temperature (perhaps averaged over a given temperature range), while...
• Initial accuracy of a voltage regulator (or simply "the voltage accuracy") reflects the error in output voltage for a fixed regulator without taking into account temperature or aging effects on output accuracy.
• Dropout voltage - the minimum difference between input voltage and output voltage for which the regulator can still supply the specified current. A Low Drop-Out (LDO) regulator is designed to work well even with an input supply only a Volt or so above the output voltage.
• Absolute Maximum Ratings are defined for regulator components, specifying the continuous and peak output currents that may be used (sometimes internally limited), the maximum input voltage, maximum power dissipation at a given temperature, etc.
• Output noise (thermal white noise) and output dynamic impedance may be specified as graphs versus frequency, while output ripple noise (mains "hum" or switch-mode "hash" noise) may be given as peak-to-peak or RMS voltages, or in terms of their spectra.
• Quiescent current in a regulator circuit is the current drawn internally, not available to the load, normally measured as the input current while no load is connected (and hence a source of inefficiency; some linear regulators are, surprisingly, more efficient at very low current loads than switch-mode designs because of this).

Electromechanical regulators

In older electromechanical regulators, voltage regulation is easily accomplished by coiling the sensing wire to make an electromagnet. The magnetic field produced by the current attracts a moving ferrous core held back under spring tension or gravitational pull. As voltage increases, so does the current, strengthening the magnetic field produced by the coil and pulling the core towards the field. The magnet is physically connected to a mechanical power switch, which opens as the magnet moves into the field. As voltage decreases, so does the current, releasing spring tension or the weight of the core and causing it to retract. This closes the switch and allows the power to flow once more.
If the mechanical regulator design is sensitive to small voltage fluctuations, the motion of the solenoid core can be used to move a selector switch across a range of resistances or transformer windings to gradually step the output voltage up or down, or to rotate the position of a moving-coil AC regulator.
Early automobile generators and alternators had a mechanical voltage regulator using one, two, or three relays and various resistors to stabilize the generator's output at slightly more than 6 or 12 V, independent of the engine's rpm or the varying load on the vehicle's electrical system. Essentially, the relay(s) employed pulse width modulation to regulate the output of the generator, controlling the field current reaching the generator (or alternator) and in this way controlling the output voltage produced.
The regulators used for generators (but not alternators) also disconnect the generator when it was not producing electricity, thereby preventing the battery from discharging back into the generator and attempting to run it as a motor. The rectifier diodes in an alternator automatically perform this function so that a specific relay is not required; this appreciably simplified the regulator design.
More modern designs now use solid state technology (transistors) to perform the same function that the relays perform in electromechanical regulators.

 

Mains regulators

Electromechanical regulators have also been used to regulate the voltage on AC power distribution lines. These regulators generally operate by selecting the appropriate tap on a transformer with multiple taps. If the output voltage is too low, the tap changer switches connections to produce a higher voltage. If the output voltage is too high, the tap changer switches connections to produce a lower voltage. The controls provide a deadband wherein the controller will not act, preventing the controller from constantly hunting (constantly adjusting the voltage) to reach the desired target voltage

Coil-rotation AC voltage regulator

Basic design principle and circuit diagram for the rotating-coil AC voltage regulator.
This is an older type of regulator used in the 1920s that uses the principle of a fixed-position field coil and a second field coil that can be rotated on an axis in parallel with the fixed coil.
When the movable coil is positioned perpendicular to the fixed coil, the magnetic forces acting on the movable coil balance each other out and voltage output is unchanged. Rotating the coil in one direction or the other away from the center position will increase or decrease voltage in the secondary movable coil.
This type of regulator can be automated via a servo control mechanism to advance the movable coil position in order to provide voltage increase or decrease. A braking mechanism or high ratio gearing is used to hold the rotating coil in place against the powerful magnetic forces acting on the moving coil.

AC voltage stabilizers

A voltage stabilizer is a type of household mains regulator which uses a continuously variable autotransformer to maintain an AC output that is as close to the standard or normal mains voltage as possible, under conditions of fluctuation. It uses a servomechanism (or negative feedback) to control the position of the tap (or wiper) of the autotransformer, usually with a motor. An increase in the mains voltage causes the output to increase, which in turn causes the tap (or wiper) to move in the direction that reduces the output towards the nominal voltage.

An alternative method is the use of a type of saturating transformer called a ferroresonant transformer or constant-voltage transformer. These transformers use a tank circuit composed of a high-voltage resonant winding and a capacitor to produce a nearly constant average output with a varying input. The ferroresonant approach is attractive due to its lack of active components, relying on the square loop saturation characteristics of the tank circuit to absorb variations in average input voltage. Older designs of ferroresonant transformers had an output with high harmonic content, leading to a distorted output waveform. Modern devices are used to construct a perfect sinewave. The ferroresonant action is a flux limiter rather than a voltage regulator, but with a fixed supply frequency it can maintain an almost constant average output voltage even as the input voltage varies widely.

The ferroresonant transformers, which are also known as Constant Voltage Transformers (CVTs) or ferros, are also good surge suppressors, as they provide high isolation and inherent shortcircuit protections.

A ferroresonant transformer can operate with an input voltage range ±40% or more of the nominal voltage.

Output power factor remains in the range of 0.96 or higher from half to full load.

Because it regenerates an output voltage waveform, output distortion, which is typically less than 4%, is independent of any input voltage distortion, including notching.

Efficiency at full load is typically in the range of 89% to 93%. However, at low loads, efficiency can drop below 60% and no load losses can be as high as 20%. The current-limiting capability also becomes a handicap when a CVT is used in an application with moderate to high inrush current like motors, transformers or magnets. In this case, the CVT has to be sized to accommodate the peak current, thus forcing it to run at low loads and poor efficiency.

Minimum maintenance is required. Transformers and capacitors can be very reliable. Some units have included redundant capacitors to allow several capacitors to fail between inspections without any noticeable effect on the device's performance.

Output voltage varies about 1.2% for every 1% change in supply frequency. For example, a 2-Hz change in generator frequency, which is very large, results in an output voltage change of only 4%, which has little effect for most loads.

It accepts 100% single-phase switch-mode power supply loading without any requirement for derating, including all neutral components.

Input current distortion remains less than 8% THD even when supplying nonlinear loads with more than 100% current THD.

Drawbacks of CVTs (constant voltage transformers) are their larger size, audible humming sound, andhigh heat generation.

DC voltage stabilizers

 Many simple DC power supplies regulate the voltage using a shunt regulator such as a zener diode, avalanche breakdown diode, or voltage regulator tube. Each of these devices begins conducting at a specified voltage and will conduct as much current as required to hold its terminal voltage to that specified voltage. The power supply is designed to only supply a maximum amount of current that is within the safe operating capability of the shunt regulating device (commonly, by using a series resistor). In shunt regulators, the voltage reference is also the regulating device.

If the stabilizer must provide more power, the shunt regulator output is only used to provide the standard voltage reference for the electronic device, known as the voltage stabilizer. The voltage stabilizer is the electronic device, able to deliver much larger currents on demand.

Active regulators

Active regulators employ at least one active (amplifying) component such as a transistor or operational amplifier. Shunt regulators are often (but not always) passive and simple, but always inefficient because they (essentially) dump the excess current not needed by the load. When more power must be supplied, more sophisticated circuits are used. In general, these active regulators can be divided into several classes:

• 
  
  
  
  Linear series regulators
  
  
  
  
  
• 
  
  
  
  Switching regulators
  
  
  
  
  
• SCR regulators
  

Linear regulators

Linear regulators are based on devices that operate in their linear region (in contrast, a switching regulator is based on a device forced to act as an on/off switch). In the past, one or more vacuum tubes were commonly used as the variable resistance. Modern designs use one and unable to step-up or invert the input voltage like switched supplies.
Entire linear regulators are available as integrated circuits. These chips come in either fixed or adjustable voltage types.

Switching regulators

Switching regulators rapidly switch a series device on and off. The duty cycle of the switch sets how much charge is transferred to the load. This is controlled by a similar feedback mechanism as in a linear regulator. Because the series element is either fully conducting, or switched off, it dissipates almost no power; this is what gives the switching design its efficiency. Switching regulators are also able to generate output voltages which are higher than the input, or of opposite polarity — something not possible with a linear design.
Like linear regulators, nearly-complete switching regulators are also available as integrated circuits. Unlike linear regulators, these usually require one external component: an inductor that acts as the energy storage element. (Large-valued inductors tend to be physically large relative to almost all other kinds of componentry, so they are rarely fabricated within integrated circuits and IC regulators — with some exceptions

Comparing linear vs. switching regulators

The two types of regulators have their different advantages:

• 
  
  
  
  Linear regulators are best when low output noise (and low RFI radiated noise) is required
  
  
  
  
  
• 
  
  
  
  Linear regulators are best when a fast response to input and output disturbances is required.
  
  
  
  
  
• 
  
  
  
  At low levels of power, linear regulators are cheaper and occupy less printed circuit board space.
  
  
  
  
  
• 
  
  
  
  Switching regulators are best when power efficiency is critical (such as in portable computers), except linear regulators are more efficient in a small number of cases (such as a 5V microprocessor often in "sleep" mode fed from a 6V battery, if the complexity of the switching circuit and the junction capacitance charging current means a high quiescent current in the switching regulator).
  
  
  
  
  
• 
  
  
  
  Switching regulators are required when the only power supply is a DC voltage, and a higher output voltage is required.
  
  
  
  
  
• At high levels of power (above a few watts), switching regulators are cheaper (for example, the cost of removing heat generated is less).
  

SCR regulators

Regulators powered from AC power circuits can use silicon controlled rectifiers (SCRs) as the series device. Whenever the output voltage is below the desired value, the SCR is triggered, allowing electricity to flow into the load until the AC mains voltage passes through zero (ending the half cycle). SCR regulators have the advantages of being both very efficient and very simple, but because they cannot terminate an on-going half cycle of conduction, they are not capable of very accurate voltage regulation in response to rapidly-changing loads.

Combination (hybrid) regulators

Many power supplies use more than one regulating method in series. For example, the output from a switching regulator can be further regulated by a linear regulator. The switching regulator accepts a wide range of input voltages and efficiently generates a (somewhat noisy) voltage slightly above the ultimately desired output. That is followed by a linear regulator that generates exactly the desired voltage and eliminates nearly all the noise generated by the switching regulator. Other designs may use an SCR regulator as the "pre-regulator", followed by another type of regulator. An efficient way of creating a variable-voltage, accurate output power supply is to combine a multi-tapped transformer with an adjustable linear post-regulator.

Diode Bridge

A diovoltagede bridge or bridge rectifier is an arrangement of four diodes in a bridge configuration that provides the same polarity of output voltage for either polarity of input . When used in its most common application, for conversion of alternating current (AC) input into direct current (DC) output, it is known as a bridge rectifier. A bridge rectifier provides full-wave rectification from a two-wire AC input, resulting in lower cost and weight as compared to a center-tapped transformer design.^[1]

The essential feature of a diode bridge is that the polarity of the output is the same regardless of the polarity at the input. The diode bridge circuit is also known as the Graetz circuit after its inventor, physicist Leo Graetz.

According to the conventional model of current flow originally established by Benjamin Franklin and still followed by most engineers today, current is assumed to flow through electrical conductors from the positive to the negative pole.^[2] In actuality, free electrons in a conductor nearly always flow from the negative to the positive pole. In the vast majority of applications, however, the actual direction of current flow is irrelevant. Therefore, in the discussion below the conventional model is retained.

In the diagrams below, when the input connected to the left corner of the diamond is positive, and the input connected to the right corner is negative, current flows from the upper supply terminal to the right along the red (positive) path to the output, and returns to the lower supply terminal via the blue (negative) path.

When the input connected to the left corner is negative, and the input connected to the right corner is positive, current flows from the lower supply terminal to the right along the red path to the output, and returns to the upper supply terminal via the blue path.

In each case, the upper right output remains positive and lower right output negative. Since this is true whether the input is AC or DC, this circuit not only produces a DC output from an AC input, it can also provide what is sometimes called "reverse polarity protection". That is, it permits normal functioning of DC-powered equipment when batteries have been installed backwards, or when the leads (wires) from a DC power source have been reversed, and protects the equipment from potential damage caused by reverse polarity.

Prior to the availability of integrated circuits, a bridge rectifier was constructed from "discrete components", i.e., separate diodes. Since about 1950, a single four-terminal component containing the four diodes connected in a bridge configuration became a standard commercial component and is now available with various voltage and current ratings.

Output smoothing

For many applications, especially with single phase AC where the full-wave bridge serves to convert an AC input into a DC output, the addition of a capacitor may be desired because the bridge alone supplies an output of fixed polarity but continuously varying or "pulsating" magnitude, an attribute commonly referred to as "ripple" (see diagram above).

The function of this capacitor, known as a reservoir capacitor (or smoothing capacitor) is to lessen the variation in (or 'smooth') the rectified AC output voltage waveform from the bridge. One explanation of 'smoothing' is that the capacitor provides a low impedance path to the AC component of the output, reducing the AC voltage across, and AC current through, the resistive load. In less technical terms, any drop in the output voltage and current of the bridge tends to be canceled by loss of charge in the capacitor. This charge flows out as additional current through the load. Thus the change of load current and voltage is reduced relative to what would occur without the capacitor. Increases of voltage correspondingly store excess charge in the capacitor, thus moderating the change in output voltage / current.

The simplified circuit shown has a well-deserved reputation for being dangerous, because, in some applications, the capacitor can retain a lethal charge after the AC power source is removed. If supplying a dangerous voltage, a practical circuit should include a reliable way to safely discharge the capacitor. If the normal load cannot be guaranteed to perform this function, perhaps because it can be disconnected, the circuit should include a bleeder resistor connected as close as practical across the capacitor. This resistor should consume a current large enough to discharge the capacitor in a reasonable time, but small enough to minimize unnecessary power waste.

The capacitor and the load resistance have a typical time constant τ = RC where C and R are the capacitance and load resistance respectively. As long as the load resistor is large enough so that this time constant is much longer than the time of one ripple cycle, the above configuration will produce a smoothed DC voltage across the load.

In some designs, a series resistor at the load side of the capacitor is added. The smoothing can then be improved by adding additional stages of capacitor–resistor pairs, often done only for sub-supplies to critical high-gain circuits that tend to be sensitive to supply voltage noise.

The idealized waveforms shown above are seen for both voltage and current when the load on the bridge is resistive. When the load includes a smoothing capacitor, both the voltage and the current waveforms will be greatly changed. While the voltage is smoothed, as described above, current will flow through the bridge only during the time when the input voltage is greater than the capacitor voltage. For example, if the load draws an average current of n Amps, and the diodes conduct for 10% of the time, the average diode current during conduction must be 10n Amps. This non-sinusoidal current leads to harmonic distortion and a poor power factor in the AC supply.

In a practical circuit, when a capacitor is directly connected to the output of a bridge, the bridge diodes must be sized to withstand the current surge that occurs when the power is turned on at the peak of the AC voltage and the capacitor is fully discharged. Sometimes a small series resistor is included before the capacitor to limit this current, though in most applications the power supply transformer's resistance is already sufficient.

Output can also be smoothed using a choke and second capacitor. The choke tends to keep the current (rather than the voltage) more constant. This design is not generally used in modern equipment due to the high cost of an effective choke compared to a resistor and capacitor.

Some early console radios created the speaker's constant field with the current from the high voltage ("B +") power supply, which was then routed to the consuming circuits, (permanent magnets were then too weak for good performance) to create the speaker's constant magnetic field. The speaker field coil thus performed 2 jobs in one: it acted as a choke, filtering the power supply, and it produced the magnetic field to operate the speaker.

Polyphase diode bridges

The diode bridge can be generalized to rectify polyphase AC inputs. For example, for a three-phase AC input, a half-wave rectifier consists of three diodes, but a full-wave bridge rectifier consists of six diodes.

Nicholas Flamel, The Immortal Alchemist

Wisdom has various means for making its way into the heart of man. Sometimes a prophet comes forward and speaks. Or a sect of mystics receives the teaching of a philosophy, like rain on a summer evening, gathers it in and spreads it abroad with love. Or it may happen that a charlatan, performing tricks to astonish men, may produce, perhaps without knowing it himself, a ray of real light with his dice and magic mirrors. In the fourteenth century, the pure truth of the masters was transmitted by a book. This book fell into the hands of precisely the man who was destined to receive it; and he, with the help of the text and the hieroglyphic diagrams that taught the transmutation of metals into gold, accomplished the transmutation of his soul, which is a far rarer and more wonderful operation.

Thanks to the amazing book of Abraham the Jew all the Hermetists of the following centuries had the opportunity of admiring an example of a perfect life, that of Nicolas Flamel, the man who received the book. After his death or disappearance many students and alchemists who had devoted their lives to the search for the Philosopher's Stone despaired because they had not in their possession the wonderful book that contained the secret of gold and of eternal life. But their despair was unnecessary. The secret had become alive. The magic formula had become incarnate in the actions of a man. No ingot of virgin gold melted in the crucibles could, in color or purity, attain the beauty of the wise bookseller's pious life.

There is nothing legendary about the life of Nicolas Flamel. The Bibliotheque Nationale in Paris contains works copied in his own hand and original works written by him. All the official documents relating to his life have been found: his marriage contract, his deeds of gift, his will. His history rests solidly on those substantial material proofs for which men clamor if they are to believe in obvious things. To this indisputably authentic history, legend has added a few flowers. But in every spot where the flowers of legend grow, underneath there is the solid earth of truth.

Whether Nicolas Flamel was born at Pontoise or somewhere else, a question that historians have argued and investigated with extreme attention, seems to me to be entirely without importance. It is enough to know that towards the middle of the fourteenth century, Flamel was carrying on the trade of a bookseller and had a stall backing on to the columns of Saint-Jacques la Boucherie in Paris. It was not a big stall, for it measured only two feet by two and a half. However, it grew. He bought a house in the old rue de Marivaux and used the ground floor for his business. Copyists and illuminators did their work there. He himself gave a few writing lessons and taught nobles who could only sign their names with a cross. One of the copyists or illuminators acted also as a servant to him.

Nicolas Flamel married Pernelle, a good-looking, intelligent widow, slightly older than himself and the possessor of a little property. Every man meets once in his life the woman with whom he could live in peace and harmony. For Nicolas Flamel, Pernelle was that woman. Over and above her natural qualities, she had another which is still rarer. She was a woman who was capable of keeping a secret all her life without revealing it to anybody in confidence. But the story of Nicolas Flamel is the story of a book for the most part. The secret made its appearance with the book, and neither the death of its possessors nor the lapse of centuries led to the complete discovery of the secret.

Nicolas Flamel had acquired some knowledge of the Hermetic art. The ancient alchemy of the Egyptians and the Greeks that flourished among the Arabs had, thanks to them, penetrated to Christian countries. Nicolas Flamel did not, of course, regard alchemy as a mere vulgar search for the means of making gold. For every exalted mind the finding of the Philosopher's Stone was the finding of the essential secret of Nature, the secret of her unity and her laws, the possession of perfect wisdom. Flamel dreamed of sharing in this wisdom. His ideal was the highest that man could attain. And he knew that it could be realized through a book, for the secret of the Philosopher's Stone had already been found and transcribed in symbolic form. Somewhere it existed. It was in the hands of unknown sages who lived somewhere unknown. But how difficult it was for a small Paris bookseller to get into touch with those sages.

Nothing, really, has changed since the fourteenth century. In our day also many men strive desperately towards an ideal, the path which they know but cannot climb; and they hope to win the magic formula (which will make them new beings) from some miraculous visit or from a book written expressly for them. But for most, the visitor does not come and the book is not written. Yet for Nicolas Flamel the book was written. Perhaps because a bookseller is better situated than other people to receive a unique book; perhaps because the strength of his desire organized events without his knowledge, so that the book came when it was time. So strong was his desire, that the coming of the book was preceded by a dream, which shows that this wise and well-balanced bookseller had a tendency to mysticism.

Nicolas Flamel dreamed one night that an angel stood before him. The angel, who was radiant and winged like all angels, held a book in his hands and uttered these words, which were to remain in the memory of the hearer: "Look well at this book, Nicholas. At first you will understand nothing in it ¾ neither you nor any other man. But one day you will see in it that which no other man will be able to see." Flamel stretched out his hand to receive the present from the angel, and the whole scene disappeared in the golden light of dreams. Sometime after that the dream was partly realized.

One day, when Nicolas Flamel was alone in his shop, an unknown man in need of money appeared with a manuscript to sell. Flamel was no doubt tempted to receive him with disdainful arrogance, as do the booksellers of our day when some poor student offers to sell them part of his library. But the moment he saw the book he recognized it as the book that the angel had held out to him, and he paid two florins for it without bargaining. The book appeared to him indeed resplendent and instinct with divine virtue. It had a very old binding of worked copper, on which were engraved curious diagrams and certain characters, some of which were Greek and others in a language he could not decipher. The leaves of the book were not made of parchment, like those he was accustomed to copy and bind. They were made of the bark of young trees and were covered with very clear writing done with an iron point. These leaves were divided into groups of seven and consisted of three parts separated by a page without writing, but containing a diagram that was quite unintelligible to Flamel. On the first page were written words to the effect that the author of the manuscript was Abraham the Jew ¾ prince, priest, Levite, astrologer, and philosopher. Then followed great curses and threats against anyone who set eyes on it unless he was either a priest or a scribe. The mysterious word maranatha, which was many times repeated on every page, intensified the awe-inspiring character of the text and diagrams. But most impressive of all was the patined gold of the edges of the book, and the atmosphere of hallowed antiquity that there was about it.

Maranatha! Was he qualified to read this book? Nicolas Flamel considered that being a scribe he might read the book without fear. He felt that the secret of life and of death, the secret of the unity of Nature, the secret of the duty of the wise man, had been concealed behind the symbol of the diagram and formula in the text by an initiate long since dead. He was aware that it is a rigid law for initiates that they must not reveal their knowledge, because if it is good and fruitful for the intelligent, it is bad for ordinary men. As Jesus has clearly expressed it, pearls must not be given as food to swine. Was he qualified to read this book? Nicolas Flamel considered that being a scribe he might read the book without fear. He felt that the secret of life and of death, the secret of the unity of Nature, the secret of the duty of the wise man, had been concealed behind the symbol of the diagram and formula in the text by an initiate long since dead. He was aware that it is a rigid law for initiates that they must not reveal their knowledge, because if it is good and fruitful for the intelligent, it is bad for ordinary men. As Jesus has clearly expressed it, pearls must not be given as food to swine.

He had the pearl in his hands. It was for him to rise in the scale of man in order to be worthy to understand its purity. He must have had in his heart a hymn of thanksgiving to Abraham the Jew, whose name was unknown to him, but who had thought and labored in past centuries and whose wisdom he was now inheriting. He must have pictured him a bald old man with a hooked nose, wearing the wretched robe of his race and wilting in some dark ghetto, in order that the light of his thought might not be lost. And he must have vowed to solve the riddle, to rekindle the light, to be patient and faithful, like the Jew who had died in the flesh but lived eternally in his manuscript.

Nicolas Flamel had studied the art of transmutation. He was in touch with all the learned men of his day. Manuscripts dealing with alchemy have been found, notably that of Almasatus, which were part of his personal library. He had knowledge of the symbols of which the alchemists made habitual use. But those that he saw in the book of Abraham the Jew remained dumb for him. In vain, he copied some of the mysterious pages and set them out in his shop, in the hope that some visitor conversant with the Cabala would help him to solve the problem. He met with nothing but the laughter of skeptics and the ignorance of pseudo-scholars ¾ just as he would today if he showed the book of Abraham the Jew either to pretentious occultists or to the scholars at the Academie des Inscriptions et Belles Lettres.

Nicholas Flamel's Journey

For twenty-one years, he pondered the hidden meaning of the book. That is really not that long. He is favored among men for whom twenty-one years are enough to enable him to find the key of life. At the end of twenty-one years, Nicolas Flamel had developed in himself sufficient wisdom and strength to hold out against the storm of light involved by the coming of truth to the heart of man. Only then did events group themselves harmoniously according to his will and allow him to realize his desire. For everything good and great that happens to a man is the result of the co-ordination of his own voluntary effort and a malleable fate.

No one in Paris could help Nicolas Flamel understand the book. Now, this book had been written by a Jew, and part of its text was in ancient Hebrew. The Jews had recently been driven out of France by persecution. Nicolas Flamel knew that many of these Jews had migrated to Spain. In towns such as Malaga and Granada, which were still under the more enlightened dominion of the Arabs, there lived prosperous communities of Jews and flourishing synagogues, in which scholars and doctors were bred. Many Jews from the Christian towns of Spain took advantage of the tolerance extended by the Moorish kings and went to Granada to learn. There they copied Plato and Aristotle ¾ forbidden texts in the rest of Europe ¾ and returned home to spread abroad the knowledge of the ancients and of the Arab masters.

Nicolas Flamel thought that in Spain he might meet some erudite Cabalist who would translate the book of Abraham for him. Travelling was difficult, and without a strong-armed escort, safe passage was nearly impossible for a solitary traveler. Flamel made therefore a vow to St James of Compostela, the patron saint of his parish, to make a pilgrimage. This was also a means of concealing from his neighbors and friends the real purpose of his journey. The wise and faithful Pernelle was the only person who was aware of his real plans. He put on the pilgrim's attire and shell-adorned hat, took the staff, which ensured a certain measure of safety to a traveler in Christian countries, and started off for Galicia. Since he was a prudent man and did not wish to expose the precious manuscript to the risks of travel, he contented himself with taking with him a few carefully copied pages, which he hid in his modest baggage.

Nicolas Flamel has not recounted the adventures that befell him on his journey. Possibly he had none. It may be that adventures happen only to those who want to have them. He has told us merely that he went first to fulfil his vow to St James. Then he wandered about Spain, trying to get into relations with learned Jews. But they were suspicious of Christians, particularly of the French, who had expelled them from their country. Besides, he had not much time. He had to remember Pernelle waiting for him, and his shop, which was being managed only by his servants. To a man of over fifty on his first distant journey, the silent voice of his home makes a powerful appeal every evening.

In discouragement, he started his homeward journey. His way lay through Leon, where he stopped for the night at an inn and happened to sup at the same table as a French merchant from Boulogne, who was travelling on business. This merchant inspired him with confidence and trust, and he whispered a few words to him of his wish to find a learned Jew. By a lucky chance the French merchant was in relations with a certain Maestro Canches, an old man who lived at Leon, immersed in his books. Nothing was easier than to introduce this Maestro Canches to Nicolas Flamel, who decided to make one more attempt before leaving Spain.

One can easily appreciate the depth of the scene when the profane merchant of Boulogne has left them, and the two men are face to face. The gates of the ghetto close. Maestro Canches' only thought is expressed by a few polite words to rid himself as quickly as he can of this French bookseller, who has deliberately dulled the light in his eye and clothed himself in mediocrity (for the prudent traveler passes unnoticed). Flamel speaks, reticently at first. He admires the knowledge of the Jews. Thanks to his trade, he has read a great many books. At last he timidly lets fall a name, which hitherto has aroused not a spark of interest in anyone to whom he has spoken ¾ the name of Abraham the Jew, prince, priest, Levite, astrologer and philosopher. Suddenly Flamel sees the eyes of the feeble old man before him light up. Maestro Canches has heard of Abraham the Jew! He was a great master of the wandering race, perhaps the most venerable of all the sages who studied the mysteries of the Cabala, a higher initiate, one of those who rise the higher the better they succeed in remaining unknown. His book existed and disappeared centuries ago. But tradition says it has never been destroyed, that it is passed from hand to hand and that it always reaches the man whose destiny it is to receive it. Maestro Canches has dreamed all his life of finding it. He is very old, close to death, and now the hope that he has almost given up is near realization. The night goes by, and there is a light over the two heads bent over their work. Maestro Canches is translating the Hebrew from the time of Moses. He is explaining symbols that originated in ancient Chaldea. How the years fall from these two men, inspired by their common belief in truth.

But the few pages that Flamel had brought are not enough to allow the secret to be revealed. Maestro Canches made up his mind at once to accompany Flamel to Paris, but his extreme age was an obstacle. Furthermore, Jews were not allowed in France. He vowed to rise above his infirmity and convert his religion! For many years now, he had been above all religions. So the two men, united by their indissoluble bond, headed off along the Spanish roads north.

The ways of Nature are mysterious. The nearer Maestro Canches came to the realization of his dream, the more precarious became his health, and the breath of life weakened in him. Oh God! he prayed, grant me the days I need, and that I may cross the threshold of death only when I possess the liberating secret by which darkness becomes light and flesh spirit!

But the prayer was not heard. The inflexible law had appointed the hour of the old man's death. He fell ill at Orleans, and in spite of all Flamel's care, died seven days later. As he had converted and Flamel did not want to be suspected of bringing a Jew into France, he had him piously buried in the church of Sante-Croix and had masses said in his honor. For he rightly thought that a soul that had striven for so pure an aim and had passed at the moment of its fruition. could not rest in the realm of disembodied spirits.

Flamel continued his journey and reached Paris, where he found Pernelle, his shop, his copyists, and his manuscripts safe and sound. He laid aside his pilgrim's staff. But now everything was changed. It was with a joyous heart that he went his daily journey from house to shop, that he gave writing lessons to illiterates and discussed Hermetic science with the educated. From natural prudence, he continued to feign ignorance, in which he succeeded all the more easily because knowledge was within him. What Maestro Canches had already taught him in deciphering a few pages of the book of Abraham the Jew was sufficient to allow his understanding of the whole book. He spent three years more in searching and in completing his knowledge, but at the end of this period, the transmutation was accomplished. Having learned what materials were necessary to put together beforehand, he followed strictly the method of Abraham the Jew and changed a half-pound of mercury first into silver, and then into virgin gold. And simultaneously, he accomplished the same transmutation in his soul. From his passions, mixed in an invisible crucible, the substance of the eternal spirit emerged.

The Philosopher's Stone

From this point, according to historical records, the little bookseller became rich. He established many low-income houses for the poor, founded free hospitals, and endowed churches. But he did not use his riches to increase his personal comfort or to satisfy his vanity. He altered nothing in his modest life. With Pernelle, who had helped him in his search for the Philosopher's Stone, he devoted his life to helping his fellow men. "Husband and wife lavished succor on the poor, founded hospitals, built or repaired cemeteries, restored the front of Saint Genevieve des Ardents and endowed the institution of the Quinze-Vingts, the blind inmates of which, in memory of this fact, came every year to the church of Saint Jacques la Boucherie to pray for their benefactor, a practice which continued until 1789," wrote historian Louis Figuier.

At the same time that he was learning how to make gold out of any material, he acquired the wisdom of despising it in his heart. Thanks to the book of Abraham the Jew, he had risen above the satisfaction of his senses and the turmoil of his passions. He knew that man attains immortality only through the victory of spirit over matter, by essential purification, by the transmutation of the human into the divine. He devoted the last part of his life to what Christians call the working out of personal salvation. But he attained his object without fasting or asceticism, keeping the unimportant place that destiny had assigned him, continuing to copy manuscripts, buying and selling, in his new shop in the rue Saint-Jacques la Boucherie. For him, there was no more mystery about the Cemetery of the Innocents, which was near his house and under the arcades of which he liked to walk in the evenings. If he had the vaults and monuments restored at his own expense, it was nothing more than compliance with the custom of his time. He knew that the dead who had been laid to rest there were not concerned with stones and inscriptions and that they would return, when their hour came, in different forms, to perfect themselves and die anew. He knew the trifling extent to which he could help them. Yet he had no temptation to divulge the secret that had been entrusted to him through the book, for he was able to measure the lowest degree of virtue necessary for the possession of it, and he knew that the revelation of the secret to an undeveloped soul only increased the imperfection of that soul.

And when he was illuminating a manuscript and putting in with a fine brush a touch of skyblue into the eye of an angel, or of white into a wing, no smile played on his grave face, for he knew that pictures are useful to children; moreover, it is possible that beautiful fantasies which are pictured with love and sincerity may become realities in the dream of death. Though he knew how to make gold, Nicolas Flamel made it only three times in the whole of his life and then, not for himself, for he never changed his way of life; he did it only to mitigate the evils that he saw around him. And this is the single touchstone that convinces that he really attained the state of adept.

This "touchstone" test can be used by everyone and at all times. To distinguish a man's superiority, there is but a single sign: a practical and not an alleged-contempt for riches. However great may be a man's active virtues or the radiant power of his intelligence, if they are accompanied by the love of money that most eminent men possess, it is certain that they are tainted with baseness. What they create under the hypocritical pretext of good will bear within it the seeds of decay. Unselfishness and innocence alone is creative, and it alone can help to raise man.

Flamel's generous gifts aroused curiosity and even jealousy. It seemed amazing that a poor bookseller should found almshouses and hospitals should build houses with low rents, churches and convents. Rumors reached the ears of the king, Charles VI, who ordered Cramoisi, a member of the Council of State, to investigate the matter. But thanks to Flamel's prudence and reticence, the result of the inquiries was favorable to him.

The rest of Flamel's life passed without special event. It was actually the life of a scholar. He went from his house in the rue de Marivaux to his shop. He walked in the Cemetery of the Innocents, for the imagination of death was pleasant to him. He handled beautiful parchments. He illuminated missals. He paid devout attention to Pernelle as she grew old, and he knew that life holds few better things than the peace of daily work and a calm affection.

The "Death" of Flamel

Pernelle died first; Nicolas Flamel reached the age of eighty. He spent the last years of his life writing books on alchemy. He carefully settled his affairs and planned how he was to be buried: at the end of the nave of Saint Jacques la Boucherie. The tombstone to be laid over his body had already been made. On this stone, in the middle of various figures, there was carved a sun above a key and a closed book. It contains the symbols of his life and can still be seen at his gravesite in the Musee de Cluny in Paris. His death, to which he joyfully looked forward, was as circumspect and as perfect as his life.

As it is equally useful to study men's weaknesses as their finest qualities, we may mark Flamel's weakness. This sage, who attached importance only to the immortality of his soul and despised the ephemeral form of the body, was inspired as he grew old with a strange taste for the sculptural representation of his body and face. Whenever he had a church built, or even restored, he requested the sculptor to represent him, piously kneeling, in a comer of the pediment of the facade. He had himself twice sculptured on an arch in the Cemetery of the Innocents: once as he was in his youth and once old and infirm. When he had a new house built in the rue de Montmorency, on the outskirts of Paris, eleven saints were carved on the front, but a side door was surmounted with a bust of Flamel.

The bones of sages seldom rest in peace in their grave. Perhaps Nicolas Flamel knew this and tried to protect his remains by ordering a tombstone of great weight and by having a religious service held for him twelve times a year. But these precautions were useless. Hardly was Flamel dead when the report of his alchemical powers and of his concealment somewhere of an enormous quantity of gold spread through Paris and the world. Everyone who was seeking the famous projection powder, which turns all substances into gold, came prowling round all the places where he had lived in the hope of finding a minute portion of the precious powder. It was said also that the symbolical figures which he had had sculptured on various monuments gave, for those who could decipher it, the formula of the Philosopher's Stone. There was not a single alchemist but came in pilgrimage to study the sacred science on the, stones of Saint-Jacques- la Boucherie, or the Cemetery of the Innocents. The sculptures and inscriptions were broken off under cover of darkness and removed. The cellars of his house were searched and the walls examined.

According to author Albert Poisson, towards the middle of the sixteenth century a man who had a well-known name and good credentials, which were no doubt fictitious, presented himself before the parish board of Saint-Jacques la Boucherie. He said he wished to carry out the vow of a dead friend, a pious alchemist, who, on his deathbed, had given him a sum of money with which to repair Flamel's house. The board accepted the offer. The unknown man had the cellars ransacked under the pretext of strengthening the foundations; wherever he saw a hieroglyph he found some reason for knocking down the wall at that point. Having found nothing, he disappeared, forgetting to pay the workmen. Not long afterwards, a Capuchin friar and a German baron are said to have discovered in the house some stone vials full of a reddish powder ¾ allegedly the projection powder. By the seventeenth century, the various houses which had belonged to Flamel were despoiled of their ornaments and decorations, and there was nothing of them left but the four bare walls.

History of the Book of Abraham the Jew

What had happened to the book of Abraham the Jew ? Nicolas Flamel had bequeathed his papers and library to a nephew named Perrier, who was interested in alchemy and of whom he was very fond. Absolutely nothing is known of Perrier. He no doubt benefited by his uncle's teachings and spent a sage's life in the munificent obscurity that Flamel prized so dearly, but had not been able altogether to maintain during the last years of his life. For two centuries the precious heritage was handed down from father to son, without anything being heard of it. Traces of it are found again in the reign of Louis XIII. A descendant of Flamel, named Dubois, who must still have possessed a supply of the projection powder, threw off the wise reserve of his ancestor and used the powder to dazzle his contemporaries. In the presence of the King, he changed leaden balls with it into gold. As a result of this experiment, it is known he had many interviews with Cardinal de Richelieu, who wished to extract his secret. Dubois, who possessed the powder but was unable to understand either Flamel's manuscripts or the book of Abraham the Jew, could tell him nothing and was soon imprisoned at Vincennes. It was found that he had committed certain offences in the past, and this enabled Richelieu to get him condemned to death and confiscate his property for his own benefit. At the same time the proctor of the Chitelet, no doubt by order of Richelieu, seized the houses that Flamel had owned and had them searched from top to bottom. About this time, at the church of Saint-Jacques la Boucherie, robbers made their way in during the night, lifted Flamel's tombstone and broke open his coffin. It was after this incident that the rumor spread that the coffin had been found empty, and that it had never contained the body of Flamel, who was supposed to be still alive.

Through whatever means, it is believed Richelieu took possession of the book of Abraham the Jew. He built a laboratory at the Chateau of Rueil, which he often visited to read through the master's manuscripts and to try to interpret the sacred hieroglyphs. But that which a sage like Flamel had been able to understand only after twenty-one years of meditation was not likely to be at once accessible to a politician like Richelieu. Knowledge of the mutations of matter, of life and death, is more complex than the art of planning strategies or administering a kingdom. Richelieu's search gave no good results.

On the death of the cardinal, all traces of the book were lost, or rather, all traces of the text, for the diagrams have often been reproduced. Indeed, the book must have been copied, for it is recorded in the seventeenth century that the author of the Tresor des Recherches et Antiquites Gauloises made a journey to Milan to see a copy which belonged to the Seigneur of Cabrieres. In any case, the mysterious book has now disappeared. Perhaps a copy or the original itself rests under the dust of some provincial library. And it may be that a wise fate will send it at the proper time to a man who has the patience to ponder it, the knowledge to interpret it, the wisdom not to divulge it too soon.

Is Nicholas Flamel Still Alive?

But the mystery of the story of Flamel, which seemed to have come to an end, was revived in the seventeenth century. Louis VIV sent an archeologist named Paul Lucas on a mission to the East. He was to study antiquities and bring back any inscriptions or documents that could help forward the modest scientific efforts then being made in France. A scholar had in those days to be both a soldier and an adventurer. Paul Lucas united in himself the qualities of a Salomon Reinach and a Casanova. He was captured by Barbary corsairs, who robbed him, according to his own story, of the treasures he had brought from Greece and Palestine. The most valuable contribution that this official emissary made to science is summarized in the story he tells in his Voyage dans la Turquie, which he published in 1719. His account enables men of faith to reconstitute part of the history of the book of Abraham the Jew.

The story goes as follows: At Broussa Paul Lucas made the acquaintance of a kind of philosopher, who wore Turkish clothes, spoke almost every known language and, in outward appearance, belonged to the type of man of whom it is said that they " have no age." Thanks to his own cultured presence, Lucas came to know him fairly well, and this is what he learned. This philosopher was a member of a group of seven philosophers, who belonged to no particular country and traveled all over the world, having no other aim than the search for wisdom and their own development. Every twenty years they met at a pre-determined place, which happened that year to be Broussa. According to him, human life ought to have an infinitely longer duration than we admit; the average length should be a thousand years. A man could live a thousand years if he had knowledge of the Philosopher's Stone, which, besides being knowledge of the transmutation of metals, was also knowledge of the Elixir of life. The sages possessed it and kept it for themselves. In the West, there were only a few such sages. Nicolas Flamel had been one of them. Paul Lucas was astonished that a Turk, whom he had met by chance at Broussa, should be familiar with the story of Flamel. He was still more astonished when the Turk told him how the book of Abraham the Jew had come into Flamel's possession, for hitherto no one had known this.

“Abraham the Jew was a member of our group," the man told him. "He had determined not to lose sight of the descendants of his brothers who had taken refuge in France. He had a desire to see them, and in spite of all we could do to dissuade him he went to Paris. He made the acquaintance there of a rabbi who was seeking the Philosopher's Stone, and our friend became intimate with the rabbi and was able to explain much to him. But before he left the country the rabbi, by an act of treachery, killed our brother to get possession of his book and papers. The rabbi was arrested, convicted of this and other crimes and burned alive. The persecution of the Jews in France began not long afterwards, and they were expelled from the country. The book of Abraham was sold to Flamel by a Jewish man who did not know its value and was anxious to get rid of it before leaving Paris. Having discovered the Philosopher's Stone, Flamel was able to remain alive in the physical form he possessed at the time of his discovery. Pernelle's and his own funerals and the minute care he bestowed on the arrangements for them had been nothing but clever shams.”

But the most amazing thing that Paul Lucas heard was the statement made by the Turk that both Flamel and his wife Pernelle were still alive! Having discovered the Philosopher's Stone, Flamel had been able to remain alive in the physical form he possessed at the time of his discovery. Pernelle's and his own funerals and the minute care he bestowed on the arrangements for them had been nothing but clever shams. He had started out for India, the country of the initiates, where he still lived. The publication of Paul Lucas' book created a great sensation. In the seventeenth century, like today, there lived discerning men who believed that all truth came out of the East and that there were in India adepts who possessed powers infinitely greater than those that science so parsimoniously metes out to us. In fact, this is a belief that has existed at every period in modern human history.

Was Nicolas Flamel one of these adepts? Even if he was, can it reasonably be presumed that he was alive three centuries after his supposed death, by virtue of a deeper study than had yet been made of the life force and the means of prolonging it? Is it relevant to compare with Paul Lucas' story another tradition reported by Abbe Vilain, who says that in the seventeenth century, Flamel visited Monsieur Desalleurs, the French ambassador to the Sublime Porte? Every man, according to his feeling for the miraculous, must come to his own conclusion. I think, myself, that in accordance with the wisdom which he had always shown, Nicolas Flamel, after his discovery of the Philosopher's Stone, would have had no temptation to evade death; for he regarded death merely as the transition to a better state. In obeying, without seeking escape, the ancient and simple law that reduces man to dust when the curve of his life is ended, he gave proof of a wisdom that is none the less beautiful for being widespread.