What to use in this

Discussion in 'The Projects Forum' started by mankomal, Mar 12, 2013.

  1. mankomal

    Thread Starter New Member

    Mar 12, 2013
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    Hello,

    I have this circuit but its not working with the components I am using
    some details about the circuit :
    The GPIO pins generate 3.3V DC
    I am using a 470 Ohm resistor
    using a CPN2222 transistor
    instead of 6v i am using a 12v battery for the motor
    can some one suggest me what should be used and what I am doing wrong coz every time a 3.3V current is generated from GPIO pins motor should rotate, but currently nothing happens.

    thanks in advance
     
  2. #12

    Expert

    Nov 30, 2010
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    How much current does the motor need to start? That means, "Locked rotor current" because all motors start from zero RPM and, for a short time, draw as much current as if they were in a stalled condition.
     
  3. mankomal

    Thread Starter New Member

    Mar 12, 2013
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  4. #12

    Expert

    Nov 30, 2010
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    That motor is recommended for use with a 20 amp controller.
    Are you trying to supply it with a transistor that can't survive 1 watt of power?
     
  5. mankomal

    Thread Starter New Member

    Mar 12, 2013
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    As stupid it may sound but yes
    So what should I do ? to make this work ?
     
  6. takao21203

    Distinguished Member

    Apr 28, 2012
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    463
    Not the right transistor.

    Use a IRF MOSFET, or larger power transistor.
     
  7. mankomal

    Thread Starter New Member

    Mar 12, 2013
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    can you suggest some part no. and the current circuit will work good ?
     
  8. #12

    Expert

    Nov 30, 2010
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    The controller price is listed in Rupees from India?
    Not likely because that translates to 12 cents, American.

    http://coinmill.com/INR_calculator.html#INR=6.50

    If 12 cents is true, buy the controller.
    Other wise, try a logic level MOSFET rated for more than 20 amps.

    I'm sure you will want to correct my dismal attempt at valuing the controller.
     
  9. mankomal

    Thread Starter New Member

    Mar 12, 2013
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    @#12
    its 650INR so 12USD approx
    but how will i integrate it in my current circuit that will be an issue
     
  10. #12

    Expert

    Nov 30, 2010
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    It comes with a simple TTL/CMOS based interface that can connect directly to the IOs of an MCU.

    You typed in, "GPIO" and that seems to indicate that you are using a micro-controller of some sort. The green part is a description of the controller. It has lots of features!

    If all you want the motor to do is run in one direction, this circuit is a good place to start, but most mosfets want 5 volts on their gate. What's your preference?
     
  11. mankomal

    Thread Starter New Member

    Mar 12, 2013
    7
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    well I was planning to use this with Raspberry Pi computer
    http://www.raspberrypi.org/quick-start-guide

    yea the motor has to run only in one direction to start off
    the input voltage from the board itself (software control) is 3.3v (+/- .2V)
     
  12. #12

    Expert

    Nov 30, 2010
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    I think there are solid state relays that can operate on 3 volts. Have to go look some up.

    Guess what...they cost more than the controller board.
     
  13. #12

    Expert

    Nov 30, 2010
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    This circuit will translate the 3 volt MCU to a high enough voltage to run a MOSFET, then the MOSFET can run a motor or a relay.
     
  14. mankomal

    Thread Starter New Member

    Mar 12, 2013
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    0
    you suggest i put a Mosfet on "collector" will solve the problem
    can you suggest which mosfet to put
     
  15. #12

    Expert

    Nov 30, 2010
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    No. That drawing does not show the mosfet connected to an emitter.

    It's past my bedtime. I have to go. Somebody else will soon help you.
     
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