2HP PMDC MOTOR spike supression circuit

Discussion in 'General Electronics Chat' started by Larry_kings, Apr 26, 2013.

  1. Larry_kings

    Thread Starter New Member

    Apr 26, 2013
    4
    0
    I have been using Atmega8 + POwer mosfets IRFP250 +Mosfet gate driver (Ti's UCC series)+48v PMDC motor (2HP Cont.)

    Problem is

    Without using any protection circuitary on the gate output of the PMW speed controller My atmega8 Mcu's internal oscillator gets burned up ,
    So what should I opt to supress these spikes and reverse voltages...
     
  2. crutschow

    Expert

    Mar 14, 2008
    13,022
    3,235
    Post a diagram of your circuit.
     
  3. Larry_kings

    Thread Starter New Member

    Apr 26, 2013
    4
    0
    Block diagram
     
    • CKT.jpg
      CKT.jpg
      File size:
      49.4 KB
      Views:
      32
  4. crutschow

    Expert

    Mar 14, 2008
    13,022
    3,235
    If you have a capacitor and diode across the motor as shown, then that should suppress the motor transient voltage so you may have a ground transient problem. Do you have a single point ground for the motor and processor? That is do you run the ground to a single point near the power supply, separately run from that point to the motor and separately to the processor? You don't want any of the motor ground current going through the processor ground.
     
  5. Larry_kings

    Thread Starter New Member

    Apr 26, 2013
    4
    0
    How can I Isolate the Processor from motor ground,Because there is only a single power supply ,So how can I isolate the ground??
     
  6. ScottWang

    Moderator

    Aug 23, 2012
    4,855
    767
    You can using two powers for uC and Motor, and you can also using photocouple to transfer the signal, it will isolated from two sides.
     
  7. Larry_kings

    Thread Starter New Member

    Apr 26, 2013
    4
    0
    Sorry ,But 2 power supplies are not possibles because i am operation this thing from 2 12v series connected batteries.
     
  8. ScottWang

    Moderator

    Aug 23, 2012
    4,855
    767
    Then you should in series a photocouple with g of mosfet.
     
Loading...