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Gerhard
Joined: 30 Aug 2007 Posts: 144 Location: South Africa
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PWM frequency |
Posted: Thu Oct 11, 2007 6:06 am |
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Hi. I am driving 2 - H-bridges via the PWM function of the pic. I am using a frequency of about 800Hz. I need the output to be stable but if i up the frequency to about 5Khz the electronics has a too log propogation time to switch corectly. What is the recomended frequency for a dc motor if using pwm?? |
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PCM programmer
Joined: 06 Sep 2003 Posts: 21708
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Posted: Thu Oct 11, 2007 11:16 am |
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What H-Bridge chips are you using, and what FETs or transistors (if any) ?
What motors are you driving ?
We used LT1158 Half-bridge drivers with external FETs at 13 kHz, with
no problems. I picked that frequency since it seemed to have the
least amount of audible noise and the highest torque. |
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Gerhard
Joined: 30 Aug 2007 Posts: 144 Location: South Africa
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Posted: Thu Oct 11, 2007 12:55 pm |
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The mosfets I am using is a IRZ44 and I am using a HIP4081 driver from Intersel. The motors are normal small DC motors that is used in the wiper's of a vehicle. |
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