Connect with us

24 Volt Motor Control w/ 12 Volt Timer

Discussion in 'Sensors and Actuators' started by DYI Guy, Mar 12, 2017.

  1. DYI Guy

    DYI Guy

    4
    0
    Mar 12, 2017
    I am new to this forum but it looks like the place to go for advice so here we go. I am building an automatic feeder that requires the use of a powerful motor so I bought a 24 volt wheelchair motor off ebay. I am using the 12 volt timer to actuate a relay which starts the motor. My first attempt worked a couple of times and then ruined the timer. I am guessing the problem might have been because I did not use a relay with diode protection. I have a crude schematic of how I am planning on wiring my next attempt but I would appreciate any comments so maybe I wouldn't burn up another $60 timer. Thank you in advance Bran Feeder Wiring.JPG
     
  2. Alec_t

    Alec_t

    2,629
    693
    Jul 7, 2015
    For an extra layer of protection you could use the timer to switch on a power transistor (e.g. MOSFET) which in turn operates the relay. BTW a 60A relay is probably inadequate for this task. The rated running current for that 400W motor is ~ 18A but its startup (stall) current will be several times that.
    Welcome to EP.
     
  3. DYI Guy

    DYI Guy

    4
    0
    Mar 12, 2017
    Alec_t, thank you very much for the reply. Getting a larger relay is no problem but the MOFSET is out of my league. I have been reading on them but its not soaking in. Would I need an n or p channel, depletion type or enhancement. Ill keep reading
     
  4. Alec_t

    Alec_t

    2,629
    693
    Jul 7, 2015
    Enhancement type. Polarity would depend on the timer output spec. Can you post a link to its datasheet?
     
  5. Bluejets

    Bluejets

    3,444
    698
    Oct 5, 2014
    Timer should operate a relay coil without any other assistance. What is the timer and what is the relay details?
     
  6. DYI Guy

    DYI Guy

    4
    0
    Mar 12, 2017
    Thank you both for replying. I can find no data for the timer other than it operates on 6/12 volts and is fuse protected with a 15 amp fuse. One other issue I noticed was that the relay was not staying latched in and it was clicking rapidly. A check with the voltmeter confirmed it was opening and closing rapidly. This was with the original timer that quit working so maybe that was causing this. The_Timer.jpg Relay.JPG I attached a photo of the relay as well
     
  7. Bluejets

    Bluejets

    3,444
    698
    Oct 5, 2014
    Certainly sounds like the timer output is overloaded BUT without any diagrams of what you have actually connected to what inside the timer, then not much help in confirming this.
     
  8. DYI Guy

    DYI Guy

    4
    0
    Mar 12, 2017
    Thanks Bluejets, The timers come with 4 wires. 2 for power and 2 for motor. I have nothing else connected except the relay in place of the motor. As soon as I get my parts I am going to give this another try. If you guys don't see anything terrible wrong with this circuit I'm going to blame the old timer as the problem. Thanks for the help
     
Ask a Question
Want to reply to this thread or ask your own question?
You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.
Electronics Point Logo
Continue to site
Quote of the day

-