L297/298 chopper driver often heat up the motor while idle. I am wondering how to achieve auto current reduction, like 50% after idle for few seconds. I know we can jumper the Vref pin with another resistor and transistor to one of the LPT output, or controling the Enable pin. Either way, is software control and using LPT pin. Some commercial driver features auto current reduction during idle, how to do that?
Thread: Auto current reduction, How?
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03-06-2006, 10:21 PM #1
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Auto current reduction, How?
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03-06-2006, 10:49 PM #2
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Usually it is done by a circuit that after not seeing any step pulses for a specific time, reduces the Vref to the L297 in your case.
Phil, Still too many interests, too many projects, and not enough time!!!!!!!!
Vist my websites - http://pminmo.com & http://millpcbs.com
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03-06-2006, 11:34 PM #3
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I have this unknown source schematic suppose to have current reduction purpose?? Can someone please verify?
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03-07-2006, 01:23 AM #4
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Nope just an op amp to buffer the reference adjustment.
Phil, Still too many interests, too many projects, and not enough time!!!!!!!!
Vist my websites - http://pminmo.com & http://millpcbs.com
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