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Hoffman Amps Forum image Author Topic: Power Transformer ID  (Read 2774 times)

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Offline dpm309

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Power Transformer ID
« on: October 11, 2011, 03:22:54 pm »
Have been going through my junk pile of old amp parts and came across this old PT.  I think it came from an old Yamaha bass amp that I gutted and used the chassis for my first build, 5E3, several years ago. Have been all over the internet trying to find what the specs are for this and if it is worth keeping for an amp project but can't find anything.   I see only 2 primary and 2 secondary wires.  See attached picture.

Thanks,

Dan

Offline stingray_65

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Re: Power Transformer ID
« Reply #1 on: October 11, 2011, 08:51:32 pm »
My guess is it is for a solid state amp, no heater wires or CT.

The black wires are likely your primary, but not necessarily, did you take notes when you harvested it?

SS trannys are step down, that means 120V in <120V out, usually in the 25-50V range. Not very useful in tube amps, but they can find their way into other projects like pedal power supplies, bench top variable voltage power supplies, door bell transformer, etc.

You can always power them up with a small AC wall wart if you do not know which end is primary and measure both sides.

Ray
My mind is aglow with whirling, transient nodes of thought careening through a cosmic vapor of invention (H. Lamarr)

stratele52

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Re: Power Transformer ID
« Reply #2 on: October 12, 2011, 04:16:27 am »
+1 stingray 65

Offline dpm309

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Re: Power Transformer ID
« Reply #3 on: October 12, 2011, 11:07:46 am »
Thanks for the replies.  I guess this PT is headed to the recycle bin since I am not planning on building any solid state amps.

Dan

Offline spacelabstudio

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Re: Power Transformer ID
« Reply #4 on: October 12, 2011, 11:37:12 am »
Well a step down transformer is a step up transformer wired the other way around.  If you have some way of generating a 1V-ish sine wave (function generator, variac), you can measure the step up or step down in either direction and decide whether 120V applied on one side will yield something useful on the other side.

Chris

Offline stingray_65

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Re: Power Transformer ID
« Reply #5 on: October 12, 2011, 10:09:04 pm »
Thanks for the replies.  I guess this PT is headed to the recycle bin since I am not planning on building any solid state amps.

Dan

Hey now!

Good iron is good iron! There are lots of great projects to make besides tube amps!

Measure up the output voltage and see what you got!

LOL take that with the grain of salt, I cry on my yearly shop clean getting rid of all the good junk I collect. Believe me if I didn't have close concerned friends who are more stubborn than me I would keep every scrap.

Ray
My mind is aglow with whirling, transient nodes of thought careening through a cosmic vapor of invention (H. Lamarr)

 


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