Thank you immensly! Now sinse I have only the beginners understanding of circuitry, would you please explain why IC1 is shown only ¼ ? And did it workMessage 1 of 13 , Sep 28, 2002View Source
Thank you immensly! Now sinse I have only the beginners understanding of circuitry, would you please explain why IC1 is shown only � ? And did it work previoously? I mean did anyone ever made it? I really dont want to gather parts, etch the circuit board and then realize that something is wrong...
Actually if this thing works and anyone wants to build it for own use, why not build a few extras? Second and thirds are always easier to build; I would definitely pay for labor, parts and shipping. I think there is a limited market for the thing... Lets develop it a bit further.
Parts are not expensive at all (excluding heating element). Building this thing (actually soldering it to the board and testing out) is about 30 minutes each. If there is a need for more that 10-20 it is definitely worth doing as a college home project. Anyone up to it?
Noel - thanx again.
noel watson wrote:
Basically, for 110V 60Hz operation, where I have written 240V at the right
hand side of the circuit...rub that out....and write in 110V. Same
components, same values.
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Hi, Phase angle power regulation is probably not the way to go. It does produce some fairly nasty harmonics and your neighbours will be pissed at what it doesMessage 2 of 13 , Sep 29, 2002View SourceHi,
Phase angle power regulation is probably not the way to go. It does
produce some fairly nasty harmonics and your neighbours will be
pissed at what it does to their TV reception.
All is not lost, however.
You are not the only person faced with this problem which is why they
produce zero-switching TRIACs. These devices only switch off when
there is no voltage across them. That rules out phase angle
regulation, but enables you to build a controller that is on for a
number of cycles, and off for a number of cycles.
It would be useless as a light dimmer (because your eyes would see
the flicker), but is effective enough to control a heating element.
The basic circuitry involves producing a sawtooth waveform (with a 2
second period) and comparing against a reference voltage through a
high gain op amp circuit. The output is a square wave where the duty
cycle varies according to the reference voltage.
It isn't that hard to put together and won't produce nasty harmonics.
Depending on the size of you elements you will see you lights dim and
brighten as it switches, but that's all.
Contact me directly if you want further information.