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  1. Dear Kevin: Well I modified another MOT, adding 12 turns of wire. I used the 20 ft coils called "primary wire" from Home Depot. It's multi-stranded, plastic coated, not sure of the guage. Anyway I hooked up an electrolysis cell directly to the house mains through my transformer. My primary is 120 turns and my new secondary 12 turns. Didn't blow any circuits but the plastic just melts off the wires. It looks like when I want to step V down I need to run the MOT in reverse, 2400 turn primary, 120 turn secondary. That way at least the reactance limits the current.
  2. Audioguru: thanks. The water molecule supposedly resonates just over 14khz, at least according to the good folks at oupower forum. You mentioned earlier about paltry protection against reverse spikes in my circuit. Do you have any ideas to prevent that? One guy on above board said he fried a few mosfets before wising up.
  3. Hi; thank you everyone, for their comments-- even the negative ones! (I make my ego transparent and they go right through me!) Audioguru: (Your comments are helpful, made me look harder and see my secondary diode was wrong polarity.) The oscillator is the grounded RC, the 1meg R & 10uf cap, tapped in the middle. The transistor gate is the switch. FYI, I tested that part (without the MOT) and it worked fine in the 20usec range of my scope. Such simple oscillators are used in many commercial inverters, schematics of which you can find all over the net, but description of their workings is hard to find. You'll see all timer chips use a simple rc relationship to set the frequency. I'm combining the switching aspect of the oscillator with the gating function to let line current pass through the transformer, and no, I'm not 100% sure this will work till I try! Since my original idea of stepping up voltage by reducing primary turns is a bust, I'll just use the MOT as it meant and add another coil for the output I need. (see attached circuit.) I'm building a stan meyer hydro-torch. (See: http://www.zip.com.au/~alansch/danforth/dan1.htm http://www.rexresearch.com/meyerhy/meyerhy.htm circuit2.txt
  4. Dear Ante & Audioguru: Thanks for your replies. Yes the is the original (& final unless you have improvements) version of my circuit. The filter section provides steady DC to the RC oscillator (about the simplest I could find: see page 102 & 192 "Basic Oscillators" by Gottlieb.) Audioguru, you are correct the filter outputs 48V, but its a pot so I tap it at the 24V setting. The 1meg pot and 10uf cap allow me set the frequency where I want it, and the tap between the two components never reach above V/2 (about 12V) which is within the gate rating of my IGBT. Yes, I blow fuses, the solution I hope you gentlemen might have. Update: yesterday I shorted the secondary and tested the primary winding again, hoping the added reactance might help. Not only did I blow another fuse but the faintest spark in the secondary and now its dead. Apparently the HV side of MOTs aren't meant to handle kV's.
  5. Hi Ante. Thanks for replying. Here's the circuit. Whatever solution i use, hope it fits in a reasonable space because I already made the case for this. But at 14khz hope I'll have enough reactance in the primary so maybe will need to do nothing at all(?) circuit.txt
  6. Thanks for your reply. As a matter of fact I was gonna pulse around 14 khz inside the half-wave 60hz envelopes. It is the latter frequency causing the fuse issue. Are you saying at the former, my circuit could still work? Not so easy increasing number of turns on a microwave oven transformer secondary; 2400 turns is already a lot!
  7. Hi. I'm working on a HV project using a microwave oven transformer as the source. Rather than use the 120 turn primary winding (1:20 P2S ratio), I knocked out the magnetic shunts, removed the heater winding to make room for a new primary winding of 12 turns, upping the ratio to the secondary 1:200. Unfortunately I keep blowing fuses when I plug it in. Does anyone have an idea how to increase reactance in the primary without costing voltage at the output? (R's and caps in series cause a drop:( Thanks!
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