Large diode for a Tesla coil.

From:  Jim Lux [SMTP:jimlux-at-earthlink-dot-net]
Sent:  Sunday, April 05, 1998 3:46 PM
To:  Tesla List
Subject:  Re: Large diode for a Tesla coil.

> ----------
> From:  ESchulz531 [SMTP:ESchulz531-at-aol-dot-com]
> Sent:  Saturday, April 04, 1998 4:35 PM
> To:  tesla-at-pupman-dot-com
> Subject:  Large diode for a Tesla coil.
> All,
>      Anybody know how to build a high voltage diode (out of semi house
> products not gallium and arsenic), because if we took lots of these and
> them in series.  We could use the tesla coil to make charges with really
> potentials.  With this we could do a lot of fun things. :)
> Just a though,
> Erik

You make a HV diode by stacking up a whole bunch of regular old 1KV PIV
diodes. They need to be moderatly closely matched in terms of recovery
time, or else, equalized by resistors and capacitors. Otherwise, the first
diode to turn off takes the full voltage. The waveform, of course, makes a
difference. So, stack up a 1000 of those diodes and you'll have yourself a
1MV rectifier.

This is essentially how they make HVDC for power transmission, although the
practical details do cost a bit and take some time to figure out. At the
other end, they run the HVDC into a large inverter to make AC out of it.

For small currents, vacuum tube diodes can be built for several hundred kV.
Electrostatic forces are a big issue in the design, as is reducing X-ray
production and field emission.