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What is this electrical component CR ?

  1. Jan 13, 2012 #1
    What is this electrical component "CR"?

    Hey folks,

    Can anyone give me a hint to what the CR symbol in this wiring diagram might mean? I'm thinking it is some kind of switch...

    The equipment is a solar cell tester. Basically it traces I-V curves. In the attached picture the pins (circles) contact the solar cell (anode and cathode on the back)

    It looks like VB+ is always at the IV-Voltage+ potential. PPV-Test-1 (carried on a BNC cable to an analog card on the control PC) must compare VA+ to VB+ (for some nefarious purpose) but unless CR20 causes some potential drop I don't know why VA wouldn't simply equal VB; unless there was some defect across the solar cell. The original owner used this equipment for QC so that wouldn't surprise me.

    And yes, off to the right hand side is the IV-Voltage- and IV-Current- side.

    Any insight or any helpful references would be a godsend. I'll eventually figure the whole thing out but "cheating" a bit never hurts!
     

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  3. Jan 13, 2012 #2

    Averagesupernova

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    Re: What is this electrical component "CR"?

    I have seen in other schematics that relays are 'CR'. This looks to be the case here too.
     
  4. Jan 13, 2012 #3

    phinds

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    Re: What is this electrical component "CR"?

    cell relay
    A transmission technology that uses small fixed-length packets (cells) that can be switched at high speed. It is easier to build a switch that switches fixed-length packets than variable ones. ATM uses a type of cell relay technology.

    Google is your friend. You should learn to use it.
     
  5. Jan 13, 2012 #4
    Re: What is this electrical component "CR"?

    Try googling "CR" and you'd understand my frustration ;p

    I'm not sure if Cell Relay would be appropriate - the voltage is an analog signal, although the circuit that controls the relay is probably digital.

    I did see in wikipedia that diodes are sometimes denoted by CR.

    My thinking now is that it stands for "Control Relay"...

    Another possibility is that it is a capacitor that charges and discharges at a certain frequency - sending "packets" of charge to the analog->digital converter.
     
    Last edited: Jan 13, 2012
  6. Jan 14, 2012 #5

    jim hardy

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    Re: What is this electrical component "CR"?

    CR often means 'current rectifier', translate diode.

    i spent time trying to make sense of that drawing. my guess is it's as you said, control relay. it'd make sense to test via pushbuttons and relays rather than moving meter leads..

    must be more to that drawing.
     
  7. Jan 14, 2012 #6

    Averagesupernova

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    Re: What is this electrical component "CR"?

    The schematic I recall seeing CR in would certainly fit control relay. I have also seen diodes referred to as CR in schematics.
     
  8. Jan 16, 2012 #7
    Re: What is this electrical component "CR"?

    Thanks guys, I was hesitant to open up the equipment but I did so anyway to see what they meant. There is a OMRON G7L-1A-T in there that is switched by a 24 VPC source. So I think the controlling computer uses it to switch between the different tests.

    Thanks for all of your answers!
     
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