There are lots of Mystery transformers on eBay etc. How can you figure out what you've bought? Link to our FB page ----- / bugamps Link to our website ----- www.bugamps.com
I have 2 transformers that do not have markings or data sheet. Only a schematic of where it belongs. Do you mind if I email you some questions to help identify the pins of primary/secondary? Thank you.
Great tutorial Doug. How can I tell what the input voltage should be? Here in Australia we are 240V but every now and then I come across stuff that I am unsure of the original input voltage. I have a power transformer on my shelf that MAY have come from a US military radio so might be 115V not 240V. Is there a way to test that without letting out the magical blue smoke?
Sorry this took me so long to notice. If you apply 240 and the voltages are all 2x what you would expect, like 10v/12.6v/500+v you know it’s meant for 120v use. Don’t actually apply full voltage though. Just apply 10v or whatever and do the math to see the expected unloaded voltages.
If you want to know a very close approx. of current up to 250ma of an unknown power transformer with a center tap on the HT winding . Take the voltage of one high voltage lead to the center tap. .Then take a resistance reading. Now divide the voltage by the resistance, Take that answer and multiply it by 25. this will be a close current approximation . Test it with a known transformer and you will see its quite close for ball park purposes.
I have been trying to find a good method to use that would indicate the current carrying capability of an unknown power transformer winding for months. Your method is the first ray of hope I have found. If you have any more information in regard to how to do this please let me know. Thanks in advance.
@@bobbysparky4299 Well its a simple method and quite accurate in my experience. As I said test it with a PT you know the specs of and you will see its very close. Should work with up to 250ma power transformers.
You need to take care doing it the way I do. I use the actual high voltage ac reading by connecting the unit into the outlet. take that high voltage reading from the center tap to either high voltage secondary legs. Disconnect the power and take the resistance reading of the wires you just measured the high voltage from. Then voltage divided by resistance x 25 = current . The late Gar Gilles of Garnet Amplification points out this trick in the Book he wrote called "The How and Why of Guitar Tube Amps as "Gar" Sees It"
Doug has helped me find my mystery transformer primary and secondary pins, identified correctly. Amazing teacher!
good video, thanks
I have 2 transformers that do not have markings or data sheet. Only a schematic of where it belongs. Do you mind if I email you some questions to help identify the pins of primary/secondary? Thank you.
Great tutorial Doug.
How can I tell what the input voltage should be?
Here in Australia we are 240V but every now and then I come across stuff that I am unsure of the original input voltage.
I have a power transformer on my shelf that MAY have come from a US military radio so might be 115V not 240V.
Is there a way to test that without letting out the magical blue smoke?
Sorry this took me so long to notice. If you apply 240 and the voltages are all 2x what you would expect, like 10v/12.6v/500+v you know it’s meant for 120v use. Don’t actually apply full voltage though. Just apply 10v or whatever and do the math to see the expected unloaded voltages.
If you want to know a very close approx. of current up to 250ma of an unknown power transformer with a center tap on the HT winding . Take the voltage of one high voltage lead to the center tap. .Then take a resistance reading. Now divide the voltage by the resistance, Take that answer and multiply it by 25. this will be a close current approximation .
Test it with a known transformer and you will see its quite close for ball park purposes.
I have been trying to find a good method to use that would indicate the current carrying capability of an unknown power transformer winding for months. Your method is the first ray of hope I have found. If you have any more information in regard to how to do this please let me know. Thanks in advance.
@@bobbysparky4299 Well its a simple method and quite accurate in my experience. As I said test it with a PT you know the specs of and you will see its very close. Should work with up to 250ma power transformers.
You need to take care doing it the way I do. I use the actual high voltage ac reading by connecting the unit into the outlet. take that high voltage reading from the center tap to either high voltage secondary legs. Disconnect the power and take the resistance reading of the wires you just measured the high voltage from. Then voltage divided by resistance x 25 = current . The late Gar Gilles of Garnet Amplification points out this trick in the Book he wrote called "The How and Why of Guitar Tube Amps as "Gar" Sees It"