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Registered Member #690
Joined: Tue May 08 2007, 03:47AM
Location: New Jersey, USA
Posts: 616
Bottom line is you can only have so much current safely flowing through the winding. Since the winding has a fixed resistance, when the rated amount of current flows through it it WILL have its rated voltage across it (see Ohm's Law).
If you exceed that voltage by 10 times, the current will also increase by 10 times. Similarly, you cannot decrease the current flowing through it while maintaining the same voltage. If you use any sort of current limiting, be it resistive, inductive, capacitive, whatever, the voltage will always change directly with the current.
Registered Member #1394
Joined: Sun Mar 16 2008, 06:18PM
Location:
Posts: 111
Thanks a lot for the info, I guess I will just have to get a mot as I cannot find just a simple 120v to 500v transformer anywhere and I cannot run my 120v to 12v backward so a mot is literally the only option.
Registered Member #30
Joined: Fri Feb 03 2006, 10:52AM
Location: Glasgow, Scotland
Posts: 6706
You should be able to pick up a 120 to 480v transformer easy enough. In industry, people often want to run 120V control electronics when they only have a higher voltage supply available. I've seen transformers with a 120V secondary and a primary tapped 0, 208, 240, 400, 480, 600 for this purpose. Get one of those and run it backwards.
Registered Member #152
Joined: Sun Feb 12 2006, 03:36PM
Location: Czech Rep.
Posts: 3384
The rule is that "volt seconds" in each period must not exceed value for given transformer. For example, if you have 10V to 100V transformer, you can drive the primary with 40V at 1/4 duty cycle or at 4x higher frequency and get 400V out, without the core saturating.
Registered Member #1394
Joined: Sun Mar 16 2008, 06:18PM
Location:
Posts: 111
Where would I find a 120v to 480v transformer, I am looking on ebay but I can't find any. This is the kind of transformer that I want, a mot would work but it provides more power than I need.
Registered Member #543
Joined: Tue Feb 20 2007, 04:26PM
Location: UK
Posts: 4992
Plasmaarc452 wrote ...
Where would I find a 120v to 480v transformer, I am looking on ebay but I can't find any. This is the kind of transformer that I want, a mot would work but it provides more power than I need.
Registered Member #30
Joined: Fri Feb 03 2006, 10:52AM
Location: Glasgow, Scotland
Posts: 6706
Michael's Electronics Emporium is kind of pricey as Ebay stores go. He's also in the UK so shipping would hit you. You want something like this:
or this:
To find more, search with a term like "industrial control transformer". They are more expensive than MOTs, but if you want 500V, a MOT is the wrong tool for the job.
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Can you run a transformer backward?
