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Entry  Thu Feb 18 15:15:12 2021, yehonathan, Update, SUS, OSEM testing for SOSs OSEM_Pin_Plate.png
    Reply  Mon Feb 22 14:06:49 2021, Yehonathan, Update, SUS, OSEM testing for SOSs 
       Reply  Wed Feb 24 10:23:03 2021, Yehonathan, Update, SUS, OSEM testing for SOSs OSEM_078_LED_Spot.JPGOSEM_280_LED_Spot.JPGOSEM_117_LED_Spot.JPG
          Reply  Wed Mar 3 11:51:07 2021, Yehonathan, Update, SUS, OSEM testing for SOSs 
             Reply  Tue Mar 9 14:30:22 2021, Yehonathan, Update, SUS, OSEM testing for SOSs 
                Reply  Tue Mar 9 15:19:03 2021, Koji, Update, SUS, OSEM testing for SOSs 
                   Reply  Tue Mar 9 18:49:28 2021, Yehonathan, Update, SUS, OSEM testing for SOSs 
    Reply  Tue Feb 23 20:55:19 2021, Koji, Update, SUS, OSEM testing for SOSs SOS_OSEM.pdf
       Reply  Wed Feb 24 10:09:16 2021, yehonathan, Update, SUS, OSEM testing for SOSs 
Message ID: 15816     Entry time: Thu Feb 18 15:15:12 2021     Reply to this: 15832   15835
Author: yehonathan 
Type: Update 
Category: SUS 
Subject: OSEM testing for SOSs 

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
         
         

I still need to figure a sensible scheme for points 3-5.

 

 

Attachment 1: OSEM_Pin_Plate.png  55 kB  Uploaded Thu Feb 18 17:27:58 2021  | Show | Show all
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