I am attempting to diagnose problems with a PMT (Photo Multiplier Tube) in our lab. I have taken apart the base, and begun drawing the underlying circuitry. I have come across a circuit component that I can't find any information on. Image below:
The part in question is the red, boxy thing (i.e. not the capacitors or the resistors). It is symmetric with 6 legs/prongs, three on each side; it reminds me of an op-amp, only with 6 legs instead of 8. The leg labeled "3" is not attached to anything else in the circuit.
After scouring the web, I found something that was remotely close-seeming to this part called an "optical isolator" or "optocoupler" (there are apparently several names for it); basically a device with a transistor and a diode connected in some special way. It seemed to match up pretty well with what this was, however, there is clearly printed on this device the text "2000 uH" (micro-henries), which is a unit of inductance. There are a few other differences which make me hesitant to call this device an optical isolator.
I have image searched for anything remotely similar to this for quite some time now, and even any opto-isolators I can find don't really look like this. I have also done the obvious and searched Google for the text strings printed on the part (i.e., "PE-5768", "7946-IP" etc). So far, nothing has come up to help me identify this component.
Has anyone ever seen this part before? Can anyone tell me what it is or what it's used for?
Best Answer
It's a three-winding transformer 2:1:1 ratio, probably from Pulse Engineering.
I guess it was made in the 49th week of 1979, so it's getting pretty long in the tooth.
There is no particular reason for it to fail- it would be part of the circuit for creating the high voltage for the dynode divider chain. If all three coils measure continuity with power off, I would look to the driving circuit.