I am setting up a testing rig for the OSEMs we recently obtained. I found the schematic for the OSEM assembly from which the pin assignment can be read.
I connected the OSEM's pin plate to a female DB15 on a breakout board. I find the pin assignment (attachment 1, sorry for the image quality) to be:
| 1 |
PD Cathode |
| 2 |
LED Anode |
| 3 |
Coil end |
| 4 |
PD Anode |
| 5 |
LED Cathode |
| 6 |
Coil Start |
There are several things that need to be done for each OSEM.
1. Measuring inductance of the coils. I checked that the measurement wires don't add any measurable inductance.
2. Check that the PDs and LEDs are alive (e.g. check forward voltage drop with fluke)
3. Energize the LED and PD.
4. Check PD DC level. For this, I might need the satellite box amplifier.
5. Check LED spot position on the PD.
6. Re-engrave OSEM S/N if needed.
| OSEM # |
Coil Inductance (mH) |
Coil resistance (ohm) |
PD forward voltage (V) |
LED forward voltage (V) |
| 280 |
2.87 |
14.1 |
0.63 |
1.1 |
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I still need to figure a sensible scheme for points 3-5.
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