Thursday, October 18, 2012

Back to the Drawing Board: Making my own High Voltage Supply

Don't think I've been spending all that time since my last post idly!

That couldn't be farther from the truth. These past 6 months I've been laboring over a little circuit of mine, a custom high voltage power supply that should be able to source all the power I need to blow up some water. The power supply is built entirely from scratch and took a lot of troubleshooting to get working. And, it's not quite done yet, but its completion is in sight.

I will elaborate on the circuit later when the designs have finalized and thoroughly tested.

The system's components are outlined below (click for larger image):

Finally, some quick snapshots of the physical circuit:

Custom DC supply (from 120V mains):
110-90V tapped mains transformer

High-current 120 Vp rectifier, with about 500 uF of smoothing capacitance 

Pulse generator and H-bridge inverter:

The 555 timer is visible towards the far left of the breadboard.
The rear MOSFETS drive the H-bridge transistors in the foreground
Below is a little demo of the H-bridge's operating principle:

Flyback transformers:

A small, non-standard HV flyback, rated at 9 kV. Feeds into the CW multiplying rectifier pictured later.
A more traditional HV flyback, salvaged from an old CRT. Output is rectified internally.

CW voltage multiplying rectifiers:

Uses low ESL "doorknob" capacitors. DC output is nominally four times the AC input.