Inductor Advice

Thread Starter

R!f@@

Joined Apr 2, 2009
9,918
Possibly dried out electro caps in the feedback loop. That often causes the regulated voltage to go high.
RB threw in the right direction.
Though I did check the caps before. So there was no cap issue.
But I found a 10K gone high in the feedback loop.

Viola ! 40V came back.


Or a resistor gone high in the voltage sensing divider.
ian field said it but I just so it when I came back to tell you it is working.
It was a resistor tht gave the 60V issue


glue it with a metal filled epoxy.
I dunno about how this will effect the inductance.

For now it works.
And I found the source of the issue, I think.
Connecting CRT drops the 40V to 9V and the FET heats up. So CRT is faulty.
But I think the CRT went bad due to 60V because of the open feed back resulting in burning the inductor.
 

ian field

Joined Oct 27, 2012
6,536
RB threw in the right direction.
Though I did check the caps before. So there was no cap issue.
But I found a 10K gone high in the feedback loop.

Viola ! 40V came back.




ian field said it but I just so it when I came back to tell you it is working.
It was a resistor tht gave the 60V issue




I dunno about how this will effect the inductance.

.
The photo posted earlier shows a pretty massive core gap - a few glued joins elsewhere in the core will probably be insignificant compared to that, if anything you could put on a few less turns and still get away with no core saturations under worst conditions.
 

Thread Starter

R!f@@

Joined Apr 2, 2009
9,918
OK... So 40V works.
I will attend to glue the core a bit later
Had to replace the H OUT in the CRT.
CRT screen is working but there are issue, I think capacitors.
 
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