Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: dude on December 16, 2022, 03:09:11 pm
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Can DCV be used to determine the turns ratio of an output transformer? Everything l read talks about applying ACV to find turns ratio. Can a 1.5 dcv battery be used on the secondary to find the turns ratio by measuring the result on the primary..?
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try both
or save time and us AC volts
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... transformer? Everything l read talks about applying ACV ...
Transformers & capacitors have the property of "passing AC" from one circuit to another, while blocking DC from one circuit reaching the other circuit.
Spend some time reflecting on the physical mechanism of how transformers work, and you will find for yourself that DC cannot be used to test turns ratio.
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EM induction* occurs when there is a change in current over time. (So if there is no change in current, you won’t get induction). Transformers don’t have any direct connection between windings. So the only way to get current from one winding to another is by induction. (Hence you need VAC).
(*discovered by Michael Faraday and put into math by James Clerk Maxwell.)
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OK, DCV is direct current where ACV is alternating current. To complete the circuit need a path to ground.. ?? Maybe ground is not the word I'm looking for..? I'll read up from the valve wizard.
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Don't lose focus Dude!
Can DCV be used to determine the turns ratio of an output transformer? Everything l read talks about applying ACV to find turns ratio. Can a 1.5 dcv battery be used on the secondary to find the turns ratio by measuring the result on the primary..?
Simple answers to your two specific questions are... NO... and NO.
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Don't lose focus Dude!
I got that right away from Shooter, educating myself with the wizard, thanks.
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You are in danger of becoming a good man. :wink:
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OK, DCV is direct current where ACV is alternating current. To complete the circuit need a path to ground.. ?? ...
"Circuit" means "closed loop." You need a "closed loop" for current (direct or alternating) to flow.
"Ground" is often the "reference voltage." Reference for what? Other voltages around "the loop" (closed circuit).
Ground often is ultimately a connection to Earth/Ground (dirt) outside. But we don't need a connection to Earth/dirt to have a complete circuit. A battery-powered flashlight has a complete closed-loop/circuit, no connection to Earth, and still lights the bulb/LED.
You would do well to get some basic electricity/electronics fundamentals via NEETS (http://www.compatt.com/Tutorials/NEETS/NEETS.html). I read most of them when I was in the Navy, and snagged paper copies of the entire 24-module series.
NEETS Module 2 (http://www.compatt.com/Tutorials/NEETS/New_PDF/14174A.pdf) is about AC and Transformers.