Need a circuit

Discussion in 'General Electronics Chat' started by sujay_3819, Oct 19, 2005.

  1. sujay_3819

    Thread Starter New Member

    Oct 19, 2005
    1
    0
    Hi all,
    I am or Oracle DBA. So, do not have much knowledge on electronics and circuits. I am in need of a circuit and need help. Basically, I need a switching circuit. My requirement is this: suppose there is a DC motor connected with 2 sets of power supplies, with power being supplied in one of them initially. The other one will be initially dead. When current starts to flow on the dead pair, I need the motor to switch to that, discarding the initially used pair of power supply. I know that a relay and a 555 ic would serve the purpose, however I need the circuit diagram so that I can construct myself. Thanks.



    regards,
    Sujay PV,
    Oracle DBA,
    SAIC India.
     
  2. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    Hi,

    It's even easier than you guessed. The attached citcuit will do the switch with just a SPDT relay. Just get one with contact ratings large enough for the motor current, and a coil voltage close to the V2 potential.
     
  3. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    Hi,

    Pebe was kind enough to point out that I had the relay in circuit incorrectly. The revised circuit will work much better.
     
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