Open collector output to operate relay

Discussion in 'General Electronics Chat' started by capa_master, Nov 26, 2010.

  1. capa_master

    Thread Starter New Member

    Nov 26, 2010
    4
    0
    Hi ALL,

    I m having digital output with 150mA Max.Current and a Relay of "HLS-CMA3-B" rating:40A/14VDC 560W DC12V.

    I need to operate this relay using this DIO(transistor's Open Collector Output).

    Is this possible or any pull-up resistor is required if yes need detailed circuit.

    Please reply ASAP.
    Thanks
     
    Last edited: Nov 26, 2010
  2. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    The spec on the relay gives the coil current. If you are able to supply the necessary voltage and current, then the coil should operate placed in series with the open collector of the transistor and the required voltage source. With the 12 volt coil, the current will be 150 ma.
     
  3. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    You will need to use a diode across the relay coil to provide a path for current flow when the transistor turns off; otherwise you will blast the transistors' collector with high voltage.

    I can't seem to locate a datasheet for a HLS-CMA3-B relay. Please check the part number, and locate a datasheet for it.
     
  4. capa_master

    Thread Starter New Member

    Nov 26, 2010
    4
    0
  5. marshallf3

    Well-Known Member

    Jul 26, 2010
    2,358
    201
    It does need around 150 mA worst case @ 12V so you'll be fine if, as mentioned above, you place a snubbing diode across it. Any rectifier that's rated as fast, at least 200 PIV and good for an amp or two will work fine.
     
  6. capa_master

    Thread Starter New Member

    Nov 26, 2010
    4
    0
    [​IMG]
    I m having this diagram but need specific as i m having only single open collector output and relay specs as in link
    http://www.helishun.com/hls-cma3.html.

    Please get me out of this.

    Thanks in advance.................
     
  7. KMoffett

    AAC Fanatic!

    Dec 19, 2007
    2,574
    230
    +CTRL goes to your open collector output. GND goes to your logic common and the 12v power supply common. Connect a 1K pullup resistor between +CTRL and +12V, and you are good to go. :)
    R2/D2 is just an indicator (not a robot from Star Wars ;) ), and not necessary.

    Ken
     
  8. capa_master

    Thread Starter New Member

    Nov 26, 2010
    4
    0
    Thanks it is really a relief for me ........

    :)

    Thank you ALL
     
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