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Motor Driver IC Blown up. Wish to know what went wrong Answered

I am using 11.1V 25C 3700mAh Lipo Battery for powering up Motor driver Card (Dual DC Motor Driver 20A) Motor driver Product Link: http://robokits.co.in/motor-drives/dual-dc-motor-driver-20a .

Basically, I tried connecting two motors instead of single Motor on each motor port on the driver. So in all 4 DC motors connected as the motors had no load. As per my calculations, all 4 DC motors together cannot draw more than 4 Amps of current. DC Motor Specifications 10 RPM High Torque Dc Motor.

Link : http://robokits.co.in/motors/high-torque-dc-geared-motor-10rpm?cPath=2_3&

During this check I noticed that one of the IC LR 7843 on the motor Driver Card got burnt, the moment I powered it up with LiPo Battery.

Really don't Know why this happened.... Can someone please help me....



3 years ago

The motors probably drew a lot of current on start

Josehf Murchison

3 years ago

I can think of 4 reasons.

Defective in the first place.

Over current on startup.

If it is a full bridge:

Wired wrong so it drove past the motor to ground.

Programmed wrong so it drove past the motor to ground.

If you look at circuit A in this Instructable:

If you close transistors QC and QD or transistors QB and QE the current bypasses the motor making a dead short to ground blowing the component.


3 years ago

For one thing, the startup current can be very high.

How did you wire the motors ? In series, or parallel ?


Reply 3 years ago

Thanks for the reply.
I had connected two motors in Parallel.