What is marx generator?

Answer 1

A Marx generator is a voltage multiplier. Erwin Marx came up with the idea in the 1920's. His generator is composed of a network of capacitors (caps), interspersed with resistors. The caps are devices that store a charge. They are connected in parallel, and the resistors are included in the network to prevent the network from "shorting out" the supply when it is turned on. Let's look at that. When any two or more caps are connected in parallel, the total capacitance of the network is additive. This means a bunch of little caps hooked up in parallel add up to one big cap. And at the moment that a circuit with a big cap in it is energized, the cap looks like a "short circuit" in the first few instants of time. This can be disastrous to the supply having to try to charge a giant cap in an instant. Bad things can happen. So we have all these caps in parallel making one giant cap. But with the resistors hooked up here and there, the caps charge through the resistors, and the current stays under control. After a (good long) while, the caps are all fully charged (to the same voltage because they are in parallel). Now for some fun. The caps, in addition to being connected in parallel, are connected in series, but not "completely" so. Conductors are run from the "output" of one to the "input" on another (and so on and so on), but a "gap" is left in the wire. This is done with all the caps. The space left open between the connections is what is called a spark gap. When sufficient voltage is applied, an arc is initiated and it leaps across the gap. This leaves an ionized trail and current can flow along that trail across the gap. That's the way lightning works. The spark gaps are set up (spaced) carefully, and the electrodes are coated to allow better surface emission of electrons when the voltage climbs high enough. We're almost there. All the caps are connected in this "broken series" configuration by all these spark gaps. As the voltage is ramped up and all the caps charge, the spark gaps feel a ton of voltage stress. There is almost enough energy to initiate an arc, but not quite. If we've set everything up correctly, all the spark gaps are now near their breakdown voltage. When one of the gaps breaks down, an arc jumps the gap. The energy of at least two caps in series will stress other gaps, and that will cause the other gaps to break down and arc in a cascade effect. Jump back a moment. All our caps were in parallel, and they were all charged to some value of voltage. When the spark gaps all break down, all the caps are suddenly connected in series, so their voltage will be additive. Again, they are all discharging, and their voltages are adding. With this arrangement, a very high voltage can be achieved, and lightning can be simulated. But the real kicker is the amount of current that can be generated at that elevated voltage - all in an instant of time! The Z machine at Sandia National Labs is the biggest unit like this, and it can dump over 107 amperes in just a tiny fraction of a second. This translates into something approaching 300 x 1012 watts! And all of it right now! There's more! At the business end of the discharge, the test chamber where the lightning occurs (as a result of all the caps dumping their energy almost instantaneously), there is an almost unimaginable release of energy. Temperatures of 3.7 billion °K or 6.6 billion °F burn through whatever is in the way. You want heat? You got it! And you got links to related articles. Go check out the pics! The additional information is posted by our friends at Wikipedia, where knowledge is free.