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Default Transformer shot! (was scope SMPS/ capacitor venting)

On Sat, 20 Feb 2016 09:10:13 -0500, legg wrote:

On Sat, 20 Feb 2016 12:55:19 -0000 (UTC), Cursitor Doom
wrote:

On Sat, 20 Feb 2016 01:14:09 -0500, legg wrote:

Recheck pin function before jumping to conclusions.


Right; now re-checked. DC measurments proved (unsurprisingly) too close
together so I re-tested using 100khz instead. These are the impedances
WRT ground of the output taps of the long winding in the order they
actually come out of the transformer:
GND, 0.17ohms, 0.17ohms, 0.26ohms, 0.28ohms, 3.7ohms, 3.8ohms.
So this doesn't seem to tally up with the schematic. Or does it? I need
a pint of strong coffee to kick-start my head on this one. :-/
Anyway, later...

If the transformer is removed from the board, which seems to be the
case, you can probe the PCB for continuity between known component
leads/schematic nodes and empty PCB transformer pin lands.

Using a logical physical numbering scheme (if one is not allready
present on the actual transformer body), you can assign numbers to the
board and the schematic, for reference.

RL


I was really struggling trying to match up the pins to their particular
outputs; fortunately JC has has posted the pin-outs for this transformer
and saved me some brain cells (I can't afford to lose any more). Seems
the voltages I'm getting are not far off what they should be after all.
 
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