Hi Team,
My customer application is ventilation fan, recently he applies UL certification and need to provide value of open loop lock current. But he found the peak current is not fixed for each lock condition happen. He has no idea how to define the lock current. Could team help explain what is the reason? Is any test method can duplicate same lock current every time.
In the below waveform, CH4 is total current of motor. Customer lock the rotor first then power on the driver, there are 3 lock cycles and the first peak lock current is about 500mA, and about 250mA for 2nd, 3rd peak lock current. Customer did lots of test, the max. peak lock current can up to 700mA.
Thanks a lot.
Vincent Chen