Marx Generator Circuit Properties?

**wil3** · Nov8-09, 11:16 AM

Hello. I have several theoretical questions about Marx generator circuit operation. Note that I am in no way attempting to build one of these, as I would surely never compromise the integrity of this board by intending to build such a risky device.

I am curious about the recommended value of the resistors in the circuit. I understand that these resistors must have a high enough value so that they effectively block current during the discharge cycle, but simultaneously they must have low enough values that the capacitors can charge relatively quickly. Is there a "rule of thumb" for the optimum resistance given a certain capacitor value? I would like to minimize resistance so as to abet faster charging, but I am unsure of how low I can go without interfering with the discharge process.

Also, I am wondering whether the spark gaps may be substituted with N.O. relays in order to provide more control over the discharge timing. Would this setup save energy, or is it unrealistic because of the damage the discharge would do to the relay leads?

Thank you very much for any input.

**Bob S** · Nov8-09, 06:11 PM

Originally Posted by wil3

Hello. I have several theoretical questions about Marx generator circuit operation. Note that I am in no way attempting to build one of these, as I would surely never compromise the integrity of this board by intending to build such a risky device.

I am curious about the recommended value of the resistors in the circuit. I understand that these resistors must have a high enough value so that they effectively block current during the discharge cycle, but simultaneously they must have low enough values that the capacitors can charge relatively quickly. Is there a "rule of thumb" for the optimum resistance given a certain capacitor value? I would like to minimize resistance so as to abet faster charging, but I am unsure of how low I can go without interfering with the discharge process.

Also, I am wondering whether the spark gaps may be substituted with N.O. relays in order to provide more control over the discharge timing. Would this setup save energy, or is it unrealistic because of the damage the discharge would do to the relay leads?

Thank you very much for any input.

The resistors must be chosen based on charging RC time constant, and power (I-squared R) losses during rapid charging. If you can find NO relays that close in 100's of nanoseconds, and can hold off 1000's of volts and carry pulsed currents of 1000's of amps, use them.
Bob S