inductive motor kick back
inductive motor kick back
(OP)
im driving a motor with a FET. I am PWMing it. There is a bunch inductive kick back that is coming back and making my FET real hot.
How i do protect against that. Do i use a recirculate diode, if so then where.
BATT
|
__
-PWM---| (N-FET)
|
--
|
|
O motor (25 A)
|
|
GND
How i do protect against that. Do i use a recirculate diode, if so then where.
BATT
|
__
-PWM---| (N-FET)
|
--
|
|
O motor (25 A)
|
|
GND





RE: inductive motor kick back
Referring to your diagram above, connect the freewheel diode's cathode to the node joining the FET and motor, and the diode anode ground. Choose the diode carefully - you need a fast type, and its voltage and current ratings should be similar to those of the FET.
----------------------------------
If we learn from our mistakes,
I'm getting a great education!
RE: inductive motor kick back
I am curious how you determined that it was kick which was causing the overheating, rather than load or switching rate.
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RE: inductive motor kick back
RE: inductive motor kick back
RE: inductive motor kick back
For a good book on switching power converter theory get Switching Power Converters by Peter Wood.
Mike Cole, mc6w@earthlink.net
RE: inductive motor kick back
Mike cole, mc5w@earthlink.net