Power Trans. Load Test

Troncones · 26th January 2010, 07:01 PM

I have a pair of Gulbransen organ amp monoblocks (APS-10 and APS-13). Both are running a set of 6BQ5s in PP at 340V.

How can I test or calculate to see the load these transformers will support. I would like to use them to run two sets of 6BQ5s or 6V6s for a stereo amp. If size matters they are large.

Thanks

Tom

boywonder · 26th January 2010, 07:13 PM

Click Here for a procedure:

diytube.com :: View topic - The Dumpster Transformer Topic

aardvarkash10 · 26th January 2010, 07:28 PM

You need to load the transformer up - a series of household lightbulbs will do it.

Keep increasing the load on hte transformer until you have around a 15% drop from the open circuit voltage eg if the OC voltage was 380VAC, your maximum continuous load current should be at a voltage of 380 x 0.85 = 325.

You should run the transformer under this load for an hour or so to check that it doesn't ovrheat -no more than 55-60 degrees C, but the cooler, the better!

Bear in mind that these are generalisations and rules of thumb. Apply your own level of caution or indescretion!

Troncones · 27th January 2010, 03:33 AM

Thanks for the help.

26th January 2010, 07:01 PM	#1
Troncones diyAudio Member Join Date: Dec 2009 Location: Orange County, California.	Power Trans. Load Test I have a pair of Gulbransen organ amp monoblocks (APS-10 and APS-13). Both are running a set of 6BQ5s in PP at 340V. How can I test or calculate to see the load these transformers will support. I would like to use them to run two sets of 6BQ5s or 6V6s for a stereo amp. If size matters they are large. Thanks Tom

26th January 2010, 07:28 PM	#3
aardvarkash10 diyAudio Member Join Date: Mar 2007 Location: Auckland, NZ	You need to load the transformer up - a series of household lightbulbs will do it. Keep increasing the load on hte transformer until you have around a 15% drop from the open circuit voltage eg if the OC voltage was 380VAC, your maximum continuous load current should be at a voltage of 380 x 0.85 = 325. You should run the transformer under this load for an hour or so to check that it doesn't ovrheat -no more than 55-60 degrees C, but the cooler, the better! Bear in mind that these are generalisations and rules of thumb. Apply your own level of caution or indescretion! __________________ Yes, conservatism thrives on low intelligence and poor information. But the liberals in politics... continue to back off, yielding to the supremacy of the stupid. It's turkeys all the way down. - George Monbiot, guardian.co.uk, 6 Feb 2012

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26th January 2010, 07:13 PM	#2
boywonder diyAudio Member Join Date: Jan 2008 Location: So.Cal.	Click Here for a procedure: diytube.com :: View topic - The Dumpster Transformer Topic

27th January 2010, 03:33 AM	#4
Troncones diyAudio Member Join Date: Dec 2009 Location: Orange County, California.	Thanks for the help.

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