When I use my flyback tester on a power transformer I can only get a reading on the primary side on all transformers I know that are good. Wonder if thats typical. So, is a good test of a transformer when you put a square wave thru it with a function generator and it comes out on the secondary side?
Announcement
Collapse
No announcement yet.
Transformer Ringback testers
Collapse
X
-
Re: Transformer Ringback testers
Mains power transformers are steel-core and flyback transformers are ferrite-core with air-gap. The two core materials have different properties, mainly ringing frequency. Very good detailed article about testing them here:
https://www.repairfaq.org/sam/flytest.htm
The Anatek Blue Flyback Tester applies a narrow pulse (guess 15mA) and then counts rings.
Comment
-
Re: Transformer Ringback testers
That kit manual has the schematics, might be worth picking one up.
Few of us are testing TV flyback transformers nowadays.
I remember this thread, that shorted standby transformer could have been found sooner: https://www.badcaps.net/forum/showth...t=59625&page=6
Maybe these transformer testers need to make a comeback?
Comment
-
Re: Transformer Ringback testers
Like a guitar string, you pluck it and listen to the note decay.
I don't think you can use a signal generator - they are push-pull output and never unload the coil to let it ring and decay. Unless you add a series diode to the sig gen output.
A narrow pulse from open-collector transistor is what I see used. Same used in that youtube video but he doesn't mention it.
The question of in-circuit testing... for a SMPS, if you excite the core below where the output rectifier diodes turn on, should be able to see the ringing.
Comment
Comment