I was wondering if anybody could help me with my Simple Motor Controller 18v7 (Assembled version) - I received it last night and powered the low current side from USB, but in my rush to get the show on the road, stupidly managed to connect the high/positive side of a fully charged 7.2V 3700mAh NiMH battery to the (high current/motor side) GND terminal and the low/negative side to the to VIN terminal. After a flash of sparks and a puff of expensive blue smoke billowing away from the large power capacitor, the temperature rapidly spiked and I pulled off the power.
Powering it back up today off the USB is fine and all the low voltage side appears to work fine, but connecting the battery correctly now sends the temperature spiralling upwards, both with and without a motor connected. (EDIT: Without a load, the temperature does not rapidly increase) I’ve taken it to about 60 deg. Celsius and then removed the power for fear of damaging it further, especially seeing as parts of the component wherever the thermistor is are probably nearing 80 deg. Celsius at that point. Correction: Having left the controller for longer, it appears to now work fully. I am confused: What was the blue smoke and if something is broken, why does the controller still work?
Correction 2: I’ve done some further testing, and appear to have a grasp on the behaviour of the controller. I’ve tested at approximately 8 and 16 volts, measuring the increase in temperature during the test - it appears to be abnormally high, despite functioning in an otherwise normal way.
(All temperatures in degrees C)
Test 1 - 15.9V: 29.3 -> 37.3 in 5 seconds with motor at 100% - Safe-Start Failed at this point, ending the test.
Test 2 - 15.8V: 33.4 -> 40.6 in under 2 seconds with motor at 100% - Again, safe-start cutout ended this test.
I assume that the safe-start function is triggering because the motor driver chip is registering extreme temperatures, as this is listed in the manual as one way which safe-start failure can trigger? Is there anything I can do to fix this problem?
Thanks in advance,