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Author Topic: Power Transformer Help (non BH)  (Read 4790 times)

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Offline dmannnnn

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Power Transformer Help (non BH)
« on: November 11, 2009, 02:43:19 PM »
I have a piece of equipment for sale and an interested buyer in asia.  He wants me to convert it to 230vac.  It currently uses an Avel Lindberg 250va torroidal with dual 25vac secondaries.  I cannot seem to find anything equivalent in 230 volts.  It seems that both Avel Lindberg and Plitron only make 120vac transformers. 

Any ideas where to look?  A custom transformer would probably cost too much or take too long.  Is a step down his only option?
Harmon Kardon T60 - Hagerman Bugle - Cal Audio Labs CL15
ForePlayIII - Paramount 300B's
Klipsch RF-7/Altec Model 14/Magnepan MG12

Online Paul Joppa

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Re: Power Transformer Help (non BH)
« Reply #1 on: November 11, 2009, 03:37:45 PM »
Many companies - Hammond is one - make toroids with dual primaries for 117/234 volts. Mouser lists them.
Paul Joppa

Offline dmannnnn

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Re: Power Transformer Help (non BH)
« Reply #2 on: November 11, 2009, 03:51:10 PM »
One set of each? so it could be switchable?

Thanks!
Harmon Kardon T60 - Hagerman Bugle - Cal Audio Labs CL15
ForePlayIII - Paramount 300B's
Klipsch RF-7/Altec Model 14/Magnepan MG12

Offline Tre

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Re: Power Transformer Help (non BH)
« Reply #3 on: November 18, 2009, 05:55:39 AM »
I believe there are two 117 volt primaries. Use them in parallel for 117 and series for 234. So yes, you could make the amp switchable.

Offline dmannnnn

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Re: Power Transformer Help (non BH)
« Reply #4 on: November 20, 2009, 07:20:41 PM »
Yes, the transformer I'm using now has two 117v primaries and two 25v secondaries.  So if I wire the primaries in series and plug into a 234v line I will still get 25v at the secondaries?
Harmon Kardon T60 - Hagerman Bugle - Cal Audio Labs CL15
ForePlayIII - Paramount 300B's
Klipsch RF-7/Altec Model 14/Magnepan MG12

Offline Tre

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Re: Power Transformer Help (non BH)
« Reply #5 on: November 22, 2009, 06:55:05 AM »
Yes.



Offline Grainger49

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Re: Power Transformer Help (non BH)
« Reply #6 on: November 22, 2009, 08:07:52 AM »
Be sure to wire the two windings so they add.  If you get the second winding out of phase I think the output will be zero, theoretically zero.

Offline dmannnnn

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Re: Power Transformer Help (non BH)
« Reply #7 on: November 22, 2009, 10:29:39 AM »
Excellent.  Thanks guys.
Harmon Kardon T60 - Hagerman Bugle - Cal Audio Labs CL15
ForePlayIII - Paramount 300B's
Klipsch RF-7/Altec Model 14/Magnepan MG12