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Registered Member #2838
Joined: Fri Apr 30 2010, 07:55PM
Location: tehachapi, CA
Posts: 333
How much are you looking to spend? You can get an "off brand" for $100-$200 that is 0-250v output roughly 5KVA or a used "decent brand" one for roughly $100-$300 on ebay. If you can stay in the 15-20A area you will save a lot of money. A 30-40A model is going to cost you some serious cash... I paid less than $75 on ebay for my powerstat which is 0-140v 15A/20Amax
Registered Member #1875
Joined: Sun Dec 21 2008, 06:36PM
Location:
Posts: 635
Paralleling variacs is good in theory but in reality you make sure they are matched and all turn synchronously... Perhaps a solid state option would be more feasible?
Registered Member #190
Joined: Fri Feb 17 2006, 12:00AM
Location:
Posts: 1567
ScotchTapeLord wrote ...
Paralleling variacs is good in theory but in reality you make sure they are matched and all turn synchronously... Perhaps a solid state option would be more feasible?
I am working on that, but there are "little" problems. I am working on a buck converter, but this will give me slightly less than the 240v input. I would like 280v. A boost-buck might overshoot unless I build a lot of protection circuitry. I could wind a 1:2.5 transformer, but this is expensive to get the core for one or two units. If I find a variac at the right price this would be the cheapest option.
Registered Member #1875
Joined: Sun Dec 21 2008, 06:36PM
Location:
Posts: 635
Eh? Isn't the "overshooting" in a buck boost what you use to charge the capacitor? Just tune the boost converter to give you the proper results by varying component values... or just put a resistive divider on the output capacitor that feeds a portion of the voltage to a comparator that shuts the converter off when the voltage crosses a set threshold.
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variac -again
