I have an old toy that drives an 5V dc-motor.
The wires around the motor is brittle and suspected burnt.
This toy uses 2x 1.5V batteries or 2x 1.2V Nimh batteries for powering the whole toy. When the motor initialize or reverse in direction, it hung and causes the circuit to stall. This results in the motor to be super hot. From the picture, the resistor is Green-Black-Gold-Silver which is 50*0.1 10% = 5 Ohms 10% resistor (metal oxide)?
I suspect the 3x capacitors and 2x resistors at the motor died.
I notice that there a number of different types of resistor like metal oxide film resistor, metal film resistor, Cermet resistor, carbon film resistor, wirewound resistor.
What resistor is recommended for this application in a humid environment?
Is a fusable resistor advisable to use to prevent motor overheat?
Best Answer
Those are inductors for filtering electrical grunge produced by the motor, not resistors. And they are not the problem, especially not a problem with heating of the motor - if they were guilty, then it would be those, not the motor getting hot.
There is no evident problem with the external wiring.
Far more likely is that the simply leaf-spring brushes inside of the motor have worn and failed, and may even intermittently be shorting out.
Your question will probably be closed, as this is really a site for electrical design issues, with repair only being on topic when it can be approached with design-level information and understanding of the circuit.