|The finished and tested circuit|
The circuit's business end, the high voltage output stage, is depicted below:
|Parts are (from left): flyback transformer, Crockoft Walton multiplier, protective diodes, output resistors|
In order to prevent arcing between and within the high-voltage components, I had to submerge them all in mineral oil. While messy, this method was extremely effective at insulating the parts.
The small, innocuous-looking flyback transformer I used in my circuit is somewhat unconventional. Most HV hobbyists think of the large suction-cup sporting flyback transformers found in CRT's when they hear the term (see picture below). These transformers are frequently used to make spark generators and are easy to salvage from old TV's and computer monitors. They are generally much beefier than the downsized flyback I used in my supply, and one would expect to get more voltage from them. I experimented with using one of these in my supply, but ultimately decided against it. All such flyback transformers I found were internally rectified (AC flybacks were outmoded in TV's thirty years ago) and therefore could not be used with my CW multiplying rectifier. So despite the traditional flyback's heft, I was able to get a greater voltage output from my miniaturized version by tacking a voltage multiplier onto its AC output.
|A classic flyback transformer, salvaged from an old computer monitor|
Troubleshooting my circuit was hardly mundane; between prototypes, my circuit experienced some catastrophic failures. The aftermath of one is pictured below:
|Casualties: four power transistors, one LCM555 timer, one breadboard|
Assuming my circuit doesn't spontaneously combust again any time in the near future, I will be using it to (carefully!) charge up some gargantuan high-voltage oil filled capacitors (see below). Once I'm confident I can charge and discharge these monsters safely, I'll hook up my makeshift water accelerator barrel, and we'll see if I can replicate Peter Graneau's overunity water arc explosions.