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previous: jayfbv That may be a problem. Specs are a... -- 10/10/2004 1:27 AM View Thread

Re: 150mA....

10/10/2004 10:47 PM
loudthud
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Re: 150mA....
Dave,  
 
The first thing I would do is ohm out the whole circuit to make sure I didn't leave anything out.  
 
From the symptoms you describe I would first look at Q14, the transistor in the Sag circuit. Try just removing it to see if the B+ pops up to around 425V or so. Also, double check that you haven't reversed the C and E terminals on Q14. Next, verify that the G and S connections on the FET you substituted match those of the IRFPE50.  
 
Depending on your voltmeter, measuring voltages in this circuit will give different numbers but, with the Power Scale control at max you should see nearly the same voltage on all three terminals of the FET, within 10V or so. If they are not, report back and I outline a procedure to ohm out the FET.

 
Replies:
Dave B. Results of your sugestions... -- 10/11/2004 12:28 AM