[time-nuts] Re: 5061A HV Supply, et al.

[ed breya]

On further study of the manual and ion pump, I see that the A18 is a 
canned module, so you'd risk some damage opening it up and restoring it. 
The description also says the 3,500 volts is set by a resistor inside, 
controlling the blocking oscillator. So, it's actually not in a closed 
regulator loop, just a fixed circuit that makes about the right voltage 
when operation is in the normal range. So, the 200 meg R4 is kind of a 
load and divider, but not for voltage regulation.

I think it can still be used to monitor the output voltage, but not with 
high accuracy, which doesn't seem all that important now.

Anyway, since you'd have to wreck it to work on it, cutting it open 
should only be the last resort. Treating it like a simple black box, it 
should be fairly easy to isolate it from the system and see what it does 
with external measurements.

Ed