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AC Power Meter | PSU | UPS evaluation | Battery Testers - Chargers | CCTV => Power supply / Battery Chargers => Topic started by: giorgos on December 27, 2013, 07:00:27 PM

Title: DIY AC POWER SUPPLY 0-25V 1A
Post by: giorgos on December 27, 2013, 07:00:27 PM

I am starting this topic, in the occasion of a project, that I found in an old Elektor magazine (early 90s).
We know that there are plenty of DC regulated power supplies in market, or as schematic projects for DIY.
What about AC? The first answer is to use a variac in order to have an adjustable AC voltage source.
The point here is that "ok we have adjustable AC voltage here, But what could we do ,If we want this voltage to be regulated (indepented from load changes)?
In market there are some specialised AC power supplies but their cost is unapproachable for a common technician.
So this circuit comes to give an alternative solution with minimal cost. In any case it can not be compared with a professional AC supply ,but it will be found useful in many cases.
I will not enter in circuit analysis here, the only critical point in this circuit, is the "hand made"optocoupler, consists of two 3mm LED and a photoresistor, included both in a small box.
I am going to make this circuit as I am curius to test it. I have already made the pcb and now I have to concentrate the components to assemble them.
I didnt copy Elektor pcb because i found it a little big, with a rather big unsued area of the board.
I used for it, sprint layout software.
So it remains to integrate this project to share my conclusions.

Title: Re: DIY AC POWER SUPPLY 0-25V 1A
Post by: Kiriakos GR on December 27, 2013, 07:57:35 PM

For just adjustable AC voltage measurements I am driving with my function generator one 220V/6V transformer from the 6V side of it.
But it is a secret ...  LOL

If this project could have an output of 110W at 220V, this would be interesting to me.  :)

Title: Re: DIY AC POWER SUPPLY 0-25V 1A
Post by: giorgos on December 27, 2013, 08:05:05 PM

Your generator must have very powerful output stage  to drive a transformer!
I am sure about that as i have seen your Philips generator in other post, and really is a great instrument.

Regarding the circuit that I posted, I think that is an alternative approach.  :)

Title: Re: DIY AC POWER SUPPLY 0-25V 1A
Post by: Kiriakos GR on December 27, 2013, 08:16:13 PM

Regarding the function generator and the transformer all that is needed, is to overcome the operating current of the transformer with out any load, and yes this old Philips it can handle it.  ;)

Even as 0~25V AC at 1A, it looks good enough as DIY project.