I was recently having some problems with my motor driver and motor. To check what was wrong, when I used my multimeter to check the OUT1 and OUT2 wires, it says they are shorted. But when I supply power it spins properly. Are the black and red wires (out1 and out2) wires supposed to be shorted? (my multimeter may also be faulty as I have been having some problems with it recently as well)
Hello.
Can you clarify what specific motor and driver you are using, and elaborate on what kind of problems you started having? When you measured the short between the motor wires, were they connected to the driver? If so, could you try disconnected them from the driver and measuring the resistance between them?
Brandon
I was using a custom PCB, DRV 8874, with a Pololu Motor Pololu - HP 6V Motor with 48 CPR Encoder for 25D mm Metal Gearmotors (No Gearbox).
The problems I was experiencing were, the motor humming, and not starting when connected to the board, but when I supplied power, it worked perfectly fine. Furthermore, I had trouble with PID and Motor Reversal, Braking and etc. I think the main problem was with the motor driver I designed, instead of the motor, but it appears that the Motor Black and Red Wires, OUT1, and OUT2 have been shorted. When measured, the short isnt connected to the driver, and there is no resistance between them.
Any replies please? I need to know if I need to reorder motor, or if it is a Pololu problem, or etc.
Your post contains very little useful information, so all anyone can do is guess.
My guesses are that the problem is due to a faulty or incorrectly designed “custom” PCB, poor soldering (e.g. a solder bridge between pads) or incorrect wiring. For help with that, post clear, focused, close up pictures showing the details of the PCB, the soldering and the wiring.
Of course, if you changed any wiring while the system was powered up, the motor driver may have been destroyed.
Ill send over some information over soon. Are the wires supposed to be shorted or not? I think the problem might be my motor driver, but even when I plug it out, its shorted. I tested the motor driver and its been working like it has always.
Of course not.
The motor driver is the least likely of the issues I mentioned, unless you changed wiring while the system was powered. That can instantly destroy the driver iC.
The most productive approach with a problem like this is to assume that the problem is with your implementation of the complete circuit.
Okay. Is the motor still functionable, if they are shorted? It seems to be spinning fine, and spins in either direction with dc voltage.
I think it might be a problem with my multimeter, I need to check. My multimeter randomly says some wires are shorted, when there aren’t any shorts on the two wires. Is there a way to test if the motor works?
By the way, the short I was talking about, is in the motor itself, not the motor driver. The motor (not motor drivers) OUT1 and OUT2 wires are shorted (AKA the red and black wires).
How exactly are you determining that the motor seems to be shorted? The DC resistance of a motor like this one is on the order of a few ohms, so if you are using a multimeter in continuity test mode, it is not unusual for it to beep since the threshold can be up to tens or even hundreds of ohms. What resistance value does the meter show?
If your motor was actually shorted, it would draw excessive current when you apply voltage (and probably not spin, or maybe spin very weakly if it were intermittent). The reason I was asking if the motor was connected to the driver when you measured it is because the driver connections would influence the measurement; furthermore, measuring resistance in a powered circuit is not a good idea as it could be inaccurate or cause damage. Also, if you haven’t done so already, I recommend putting fresh batteries in your multimeter (or fully charging them). Low batteries can cause erratic issues like you described.
Brandon