Audio amplifier as AC power generator ?

Just use a transformer whos secondary voltage rating is about twice as high as you need. Then the peak flux will be about half what it was designed to run at, so even in the worst case it will never saturate further than it does during normal operation (that last bit is included because some 50/60Hz transformers saturate like hell twice per cycle. Microwave oven transformers are a good example of that, as are many autotransformers)

try it, its easy.

Or do what I did with my 3kVA light dimmer, and have transformers built that run at a peak flux density of 800mT.

And if the OP wants to produce even lower frequencies, all he needs to do is keep the ratio of volts/hertz constant, and the flux stays constant - this is how all non-vector AC motor controllers work, and is usually called V/Hz or scalar control. At very low frequencies you need to "boost" the voltage a little bit to offset IR drops.

Cheers Terry

"Terry Given" a écrit dans le message de news:

1207633815.886658@ftpsrv1...

Thanks to all (well, thanks to Phil too, I'm not a guy who holds grudges)/. Robert.

"Terry Given"

**That means finding a transformer rated at 500 volts AC at 50 Hz and a secondary of around 80 volts. Easier by far to use TWO transformers with their 240 volt windings in series and 80 volt secondaries paralled.

In fact - all the colossally stupid OP really needs is damn Variac with (

25 amp) triac at the output he can trigger on or off at whim.

....... Phil

yep, that'd do nicely, and he could probably find something 2nd hand for a few dollars.

I went to surplustronics on Sunday to get a moderate sized CT for a test rig, and they'd tossed out most of their electronics junk (because nobody bought it). I was very disappointed :(

So I got the smallest toroidal power transformer from jaycar (9-0-9), chopped off the primary, stuck a shorted turn thru the center, hooked the secondaries in series and added a 510R series resistor. Voila, feed

16Vac up it and get 2A out. short circuit the 510R and get 10A.

(I didnt actually chop the primary wires off, just trimmed the ends, heat-shrunk them & cable tied them around the xfmr. this way if I ever retire the test rig I can scavenge the toroid and still use it)

or simply have one made with more steel. its neither hard nor expensive

- my 800mT 3kVA autotransformer cost $145 1+

Not particularly, my understanding of a big tube is 2000 Watts and up, with 40,000,000 (pulse) Watts being the top end. Take a look at the Eimac / Varian catalogs. GE and RCA used to make high power transmitting tubes also. CTC made RF transistors past the kW power level.

Mmmmm. 6550s and 6164s and up, 4CX1000s, 4KX10000s.

Slightly less spiteful and condescending than Phillys; you need much more margin to properly simulate sags, surges, spikes, dropouts, and other typical line disturbances. Say about 2 kW. and appropriate generators and transformers.

Thank you Terry, you have added to my understanding.

[snip]

I have some 4CX-something-or-other's out in the garage, leftover from my 2-meter days on the '60's ;-)

...Jim Thompson

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