Where can i find an adjustable AC (AC output!) power supply? - Page 1
Forum section: electronics / testgear

author: Akra
author_rank: Contributor
timestamp: September 24, 2016, 08:08:23 pm
content: At the moment I'm searching for an adjustable AC power supply.But I can't find any. Every time I search for them I get normal DC power supplies with AC input (of course).The next best option would be to use a adjustable isolation transformer,but they are bloody expensive and I don't need voltage up to 250V, only about <50V.So, does anybody know where I can find an AC power supply?

author: JacobPilsen
author_rank: Regular Contributor
timestamp: September 24, 2016, 08:18:12 pm
content: Tahmid (Syed Tahmid Mahbub): Research on transformerless AC-ACOr some better Frequency changer.

author: SeanB
author_rank: Super Contributor
timestamp: September 24, 2016, 08:19:12 pm
content: Regular variac feeding into a suitably rated mains to 60VAC ( or somewhere between 50-80VAC ) regular transformer will work instead. That way you have both isolation ( the transformer) and adjustable voltage ( the variac) which is what you need. Plus the current rating on the secondary is the current you can draw, which for most variacs is the limiting factor, using a 50VAC secondary transformer you can get up to 4 times the current available on the 50VAC setting than what you could get using the variac alone on 230VAC mains.

author: Akra
author_rank: Contributor
timestamp: September 24, 2016, 09:26:30 pm
content: I thought in a similar way for a plan B.And thanks for the tip with the higher current, haven't thought of that.Probably I will need to build it this way, if I can't find anything.

author: nctnico
author_rank: Super Contributor
timestamp: September 24, 2016, 09:28:56 pm
content: I'd use a hifi amplifier and a function generator.

author: pmcouto
author_rank: Unknown
timestamp: September 24, 2016, 09:37:49 pm
content: Check this one:http://www.gwinstek.com/en-global/products/AC_Power_Source/AC_Power_Sources/APS-7000

author: 0xfede
author_rank: Regular Contributor
timestamp: September 24, 2016, 09:45:14 pm
content: nctnico is way faster than me.I use an old and big PA audio amplifier driven by a sinusoidal wien bridge oscillator.The only modification is that I add a trasformer to the output and I use the output of the trasformer for amplifier feedback.I strongly suggest you to use a PA amplifier cause it is more rugged.Best,0xfede

author: Cerebus
author_rank: Super Contributor
timestamp: September 25, 2016, 12:19:20 am
content: If you're looking for a bench PSU start looking for "bipolar power supply/amplifiers". There are a number of reputable suppliers out there. This is, essentially, a laboratory grade power amplifier. The difference from just using an audio power amp is stability into loads that would upset an audio power amp, in some cases higher bandwidth and of course caring about specifications that are meaningless to power amp designers like line regulation. Secondhand ones are rare, I know because I keep my eyes open for them.if you're looking for something to build in to something else in the sense of "off the shelf power supply" you're probably out of luck unless you're looking at a big enough order that you can say "Hey, TDK? Design and build these for me".

author: billfernandez
author_rank: Regular Contributor
timestamp: September 25, 2016, 12:02:11 pm
content: Do a Google search for "AC power source". You'll find quite a variety of relevant hits.

author: joeqsmith
author_rank: Super Contributor
timestamp: September 25, 2016, 03:30:57 pm
content: Quote from: 0xfede on September 24, 2016, 09:45:14 pmHere we have Crown and Techron. Techron makes some nice DC coupled amplifiers that will output a few hundred volts. More than enough BW for 60Hz work. For higher power work, I have used some equipment from California Instruments.

author: Akra
author_rank: Contributor
timestamp: September 25, 2016, 07:32:22 pm
content: Oh man, why haven't I thought of an amp, it is so easy and brilliantEverything is already here and the power should be enough, I even get the variable frequency feature.This is probably the cheapest and best solution so far, thanks a lot

author: gamalot
author_rank: Super Contributor
timestamp: September 25, 2016, 08:13:41 pm
content: https://www.kikusui.co.jp/en/product/selection.php?Category=AC%20Power%20Supplies%20(AC%20Power%20Source)

author: Yansi
author_rank: Super Contributor
timestamp: September 25, 2016, 09:44:04 pm
content: Quote from: JacobPilsen on September 24, 2016, 08:18:12 pmThat idea is wrong, Think twice about it.(a little help: Parasitic inductances)