Sparky2003
Electrical
- Jun 16, 2003
- 23
Hi - Hope someone can help.
I have a IC motor driver in a brushless dc motor which rotates a fan. I have 2 type failure modes on same application with different internal circuitry - 2 different end applications.
Failure 1: When I power the motor, it is stalled, there is large current been drawn on power supply which starts to reduce gradually, as it reduces a sound eminates from IC and incrases as current reduces - then the cycle resets and starts again.
Failure 2: Motor operates perfectly at room temperature. At low temp approx 10C the operation becomes abnormal where it loses RPM and sometimes reverse rotates 1/4 turn and back 1/4 turn repeatedly - worst case it sometimes locks up. This happens when I apply freeze spray to IC and when IC heats up and reaches 10C the failure phenomonen occurs.
All the failed devices test good parametrically and failure analysis including PEM analysis has so far shown nothing. Anyone have any advice on what may be the root cause and suggestions would be appreciated
I have a IC motor driver in a brushless dc motor which rotates a fan. I have 2 type failure modes on same application with different internal circuitry - 2 different end applications.
Failure 1: When I power the motor, it is stalled, there is large current been drawn on power supply which starts to reduce gradually, as it reduces a sound eminates from IC and incrases as current reduces - then the cycle resets and starts again.
Failure 2: Motor operates perfectly at room temperature. At low temp approx 10C the operation becomes abnormal where it loses RPM and sometimes reverse rotates 1/4 turn and back 1/4 turn repeatedly - worst case it sometimes locks up. This happens when I apply freeze spray to IC and when IC heats up and reaches 10C the failure phenomonen occurs.
All the failed devices test good parametrically and failure analysis including PEM analysis has so far shown nothing. Anyone have any advice on what may be the root cause and suggestions would be appreciated
