20,000 volt DC power supply from an old TV

by Stephen Hobley on November 12, 2010

As a follow up to the recent post about extracting components from an old TV, here is a short clip showing what I made from them :

This was shot at 12:30am so apologies if I sound a little bit “out of it”.

This is a simple 15Khz pulsed DC driver for a TV flyback transformer – following the design on the Naudin page. Once running with 50V DC input we should see over 20kV output from the HV terminal – enough to drive a “lifter”.*

A 555 timer is setup in astable oscillator mode using the 5K, 2.7K and 10nF caps (I picked the closest values I could find from the TV control board) this pulses the S2000N transistor that switches the full supply voltage into the primary winding of the flyback transformer. This pulsed DC is then rectified by the flyback internal diodes into a pulsed 20,000V output. I do have some 40,000V capacitors lying around somewhere so I could potentially smooth the output further if required.

This stuff can be dangerous – so don’t go poking around inside an old TV unless you are sure you know what you are doing.

* I was asked to replicate the Mythbuster’s episode where they build a lifter and test it out:

I’m kind of with them on this one – I don’t believe that this thing is controlling gravity, just providing thrust from accelerating ions. (Hey, is this how Twin Ion Engine Fighters work??)


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