60-70 volt brushless DC motor driver (Schematic)

Discussion in 'The Projects Forum' started by aamir_sheikh, Mar 8, 2014.

  1. aamir_sheikh

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    Nov 19, 2013
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    I am trying to make a driver for a 60 volt brushless dc motor. i want to use a charge pump with IR2110. The Nmos i am using are irf 540.
    Attached is the initial schematic, of one phase.
    Do you think there is anything wrong with it?
     
  2. MaxHeadRoom

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    What is the PWM frequency?
    You may want to go with 15v on the IR2110 VCC.
    How are you handling the commutation sensing? normally done with hall effect or equivalent method.
    Max.
     
  3. ronv

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  4. MaxHeadRoom

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  5. aamir_sheikh

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    hall sensing, going to use them on external interrupts of some controller with six or more pwm channels,
    why 15 volts?

    it might go 100% on duty cycle... i am just designing a module for a much bigger system, which i believe would be operating in rapid and sudden bidirectional movements. any one of the high side fet might get used for a long time without its lower fet getting turned on and subsequently not pulling VS to ground and not charging the bootstrap cap.
     
  6. aamir_sheikh

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    Last edited by a moderator: Mar 9, 2014
  7. ronv

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    You know aamir, the more I look at it they are both the same.
     
  8. MaxHeadRoom

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    In your 1stschematic you appear to have two charge pumps on U1 if connecting U2 as well?
    Max.
     
  9. aamir_sheikh

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    I am sorry, i don't understand you, what charge pumps?
     
  10. aamir_sheikh

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    the one in the Ti app note is powered from a separate railing, where as the one in Ir app note is powered when ever the high side switch is on, and voltage apppears on Vs ( i think ),
    and how would you suggest i use that design in a half-bridge configuration?
     
  11. aamir_sheikh

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    Also i was thinking that in me design the 26-27 volt that would appear on VB would be reduced down to 15 by the zener, but where would the extra voltage go? would it appear on VS?
     
  12. MaxHeadRoom

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    D4 and C2 is the charge pump for the IR2110, you also show a 555 C.P.?
    The Vboost is charged when the high side is modulated and there has to be a path to common via load or opposite side on in the case of a full bridge etc in order to work.
    Max.
     
  13. shortbus

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    Isn't D4 and C2 the bootstrap for the IR2110? I've never seen it called a 'charge pump' before.
     
  14. MaxHeadRoom

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    Yes, IR refer to it as a bootstrap, but I have always though of it as a charge pump in a way, as the Vboost capacitor charge requires the modulation or switching of the upper FET. By way of the resistor/diode/capacitor combo and a path to common.
    Maybe a little license with semantics on my part!
    Max.
     
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  15. aamir_sheikh

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    dt92-4 one works fine on bread board, but doesnt work in on a veroboard, i dont know why... :(

    Down anyone knows how VS pin should behave when lowside and high side switches are off?
    on breadboard(the circuit that works) Vs swings to .08v,
    and on veroboard, Vs is on 4 volts... why is that?
     
    Last edited: Mar 15, 2014
  16. MaxHeadRoom

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    VS should float at that point, but how do you have the load side connected?
    I am just in the process of experimenting with the full DC motor bridge ECCP module on a PIC but have not got that far in the hardware point yet.
    Max.
     
  17. aamir_sheikh

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    Nov 19, 2013
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    havent connected load yet, 24 volts(drain voltage) appears on VS when i turn on the high side mosfet.
     
  18. aamir_sheikh

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    Nov 19, 2013
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    just a quick update, the design in schematiccapture3 works fine, it is just like switching with transistors, I just used it in a halfbridge configuration,

    thanks to everyone who replied and helped me.
     
  19. MaxHeadRoom

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