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BLDC motor controller limit power supply current

Discussion in 'Robotics & Mechatronics' started by poofjunior, Aug 9, 2014.

  1. poofjunior

    poofjunior New Member

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    H everyone,

    I'm building a brushless motor controller for a BLDC motor with a sine wave drive. So far, I'm using three half-bridge drivers (BTN7930P) from Infineon and I'm using a microcontroller for the pwm signal generation.

    So far, the pwm signals are working correctly, and the motor does microstep from one pole to the next, but my power supply (12[v], 30[A]) keeps resetting during the commutation sequence. The motor is rated for 20 [A], but I don't know how to limit the current from the power supply.

    Does anyone know how to limit the input current from the power supply?

    Alternatively, I thought it might be more practical to limit the current from the half-bridge drivers, and I think the answer may be in the datasheet. http://www.leonvanderhorst.nl/docs/H-bridge half - BTN7930.pdf
    From the datasheet, I've been looking at the IS pin hoping that the current-sense resistor limits the current to a maximum value. Unfortunately, it looks like it only outputs an analog value indicating the current through the half bridge.

    Thanks in advance for the input!
     
  2. poofjunior

    poofjunior New Member

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    Whoop--to answer my own question: just limit the amplitude of the sine wave input.

    In other words: just limit the maximum duty cycle of the pwm frequency until the power supply stops kicking out.
     

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