Can someone tell me what this is?

Discussion in 'General Electronics Chat' started by sparkyuiop, Feb 21, 2012.

  1. sparkyuiop

    Thread Starter New Member

    Aug 19, 2011
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    It possibly came out of a 4 camera cctv kit from Maplin but I'm not sure.
    Any help welcomed.

    [​IMG]
     
  2. BillB3857

    Senior Member

    Feb 28, 2009
    2,400
    348
    Looks like a power supply.
     
  3. sparkyuiop

    Thread Starter New Member

    Aug 19, 2011
    12
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    For what though? One end is a PC COM port and the other has sring clips to hold wires. Ze mind boggles!

    This may sound silly but does it amplify the COM port signal lines?
     
  4. bertus

    Administrator

    Apr 5, 2008
    15,649
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    Hello,

    It looks like some kind of switch, as there is a relais on the board.

    Bertus
     
  5. BillB3857

    Senior Member

    Feb 28, 2009
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    Could it take data from the DB connector to switch power to individual cameras?
     
  6. sparkyuiop

    Thread Starter New Member

    Aug 19, 2011
    12
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    Yeah it's the relay that's doing my head in. Maybe there are more important things to worry about anyway!
     
  7. sparkyuiop

    Thread Starter New Member

    Aug 19, 2011
    12
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    Now were cooking with gas!
     
  8. DerStrom8

    Well-Known Member

    Feb 20, 2011
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    1,328
    I don't suppose it could be a channel selector of some sort, could it?
     
  9. colinb

    Active Member

    Jun 15, 2011
    351
    35
    There's an SPDT relay, K1 with a 5 V coil. There are four identical two-transistor circuits with three resistors each -- my guess is they are Darlington pairs. The DE-9F connector may not be an RS-232 serial port, but might be used for another purpose (plain digital I/O).

    My best guess without any more detailed analysis is that this is a relay control board. There are four channels of open-collector digital outputs and one relay output.
    Perhaps the seven wires on the wire-connectors are:
    1. GND
    2. out_oc1
    3. out_oc2
    4. out_oc3
    5. out_ov4
    6. relay1
    7. relay2
     
  10. colinb

    Active Member

    Jun 15, 2011
    351
    35
    OK, coming back to read the new responses since I started writing.

    Perhaps the relay switches power to the cameras. I don't know about the signal, however. You wouldn't be wiring a video signal to this thing using discrete wires.
     
  11. hwy101

    Active Member

    May 23, 2009
    91
    28
    That could also be a module that connects to the server serial port to turn ON lights in a house from a remote location
     
  12. sparkyuiop

    Thread Starter New Member

    Aug 19, 2011
    12
    0
    I have had a look at the Maplin 4 camera kit online but can't see this part. It does say however something about a unit that allows all the cameras to be powered at once but does not show a picture of it.
    That said, I installed the system and all the cameras were working when I left. I found this in my toolbox the next day which is why I am assuming it may have been part of that system.
    I take note what 'hwy101' said about remote lights. Not sure if that has any relevance but this system was one that was accessable to view over the internet although that was not connected up as it was not required.

    Thanks for all the input everyone.
     
  13. @android

    Member

    Dec 15, 2011
    178
    9
    My guess is it is for transferring data from CCTV to CPU.
     
  14. colinb

    Active Member

    Jun 15, 2011
    351
    35
    Would you really transfer video data over discrete wires (see the 7-wire “trap” for discrete wire hookup)?? I think signal integrity would be a fail.
     
  15. BillB3857

    Senior Member

    Feb 28, 2009
    2,400
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    I would say it depends upon the video. My X-10 cameras came with50 feet of 4 lead telephone type wire with the RJ connector for video, audio and power. They work fine for surveillance. I don't think it would work for broadcast quality.:)
     
  16. colinb

    Active Member

    Jun 15, 2011
    351
    35
    Interesting. I suppose it could be twisted-pair cable, but it looks really flat, so I'm guessing the conductors are all parallel.

    The difference is when the discrete wires are terminated individually, you probably have a larger current loop area as the signal and return (ground) conductor will be spaced farther apart than they are in your little 4-conductor cable. This potentially relatively large area would act as a something of a loop antenna to radiate significant electromagnetic interference.

    Anyway, I'd still be curious to know what the device does, but we may never know exactly!

    It sounds like the device isn't useful as it is (since its purpose and connection scheme is unknown), so it would be interesting to carefully photograph the assembly, make note of each part marking and placement, strip the parts, and scan both sides of the PCB. Then you could reverse-engineer a schematic from it and try to figure out what it does. If you have a few spare hours to have some fun, that is.
     
  17. MrChips

    Moderator

    Oct 2, 2009
    12,452
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    Why not ask Maplin?
     
  18. colinb

    Active Member

    Jun 15, 2011
    351
    35
    Oh, that just takes all the fun out of it. :)
     
  19. sparkyuiop

    Thread Starter New Member

    Aug 19, 2011
    12
    0
    Yeah, like the time I asked them if they had any 10k resistors in stock and then had to explain what they were, you mean!
     
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