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Re: 220V transformers on 120V?
Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>" <tesla-at-ian-dot-org>
On Wed, 29 May 2002, Tesla list wrote:
> I don't know much about 555 circuits, but how are you measuring the
> transistor output? If you're using a scope on the transistor output
> (essentially no load on the transistor), you may get funny readings.
> This has happened to me before. I was running on 12VDC. I put a 50 ohm
> resistor across the transistor (output to ground), and then got a good
> square wave on the scope. You don't need the resistor if you're driving
> a "real" load, of course. Just a thought.
Yes, resistors helped.. I did some more fiddling around and got
the transistor output to be close enough to the square wave
input that I am happy. A cap in series shifts it to be AC,
but making a sine wave is harder... and I'm not sure the input
to the transformer has to be sine anyway.
Is there a good reference for powering transformers out there? I
have a dozen or so small ones and have varied success in getting
output from them. I read that either high voltage or low voltage
with a high frequency will do the same job, but I am not sure
of why. How does one figure out the proper power input into
an unmarked transformer? There has to be a good web page or
book I can read to show me what I'm missing. Thanks!