Potentiometer during use, due to the rotation frequent and prone to failure. This failure performance when noise and loud when small, power failures and other switches.
　　So how do we judge the potentiometer and the bad?
　　L Electronic, here to teach you a simple potentiometer test methods.
　　Ready common tools, multimeter.
　　Example: If A, B represents the fixed end of the potentiometer, P represents wiper potentiometer. Adjusting the position of P can change the resistance between the A, P or P, B, but no matter how adjusted results should follow Where: = RAP + R ,. .
　　(1) measuring the potentiometer A, B-side total resistance meets the nominal value
　　The leads are connected between A, B, to see whether the multimeter reading is consistent with the nominal value.
　　(2) in contact with the movable arm detection resistor potentiometer is good
　　Measured with a multimeter ohm block A, P or P, at both ends of B, and slowly turn potentiometer, resistance should be continuously larger or smaller, if the resistance of the beating, then the movable contact poor contact failure.
　　(3) The quality of the measurement switch potentiometer
　　The available digital multimeter diode with a switch potentiometers, block by checking off the situation test "switch" between the two lug to determine whether it is normal. If at the time of the "switch" is closed, the digital multimeter beeps, the internal switch contact is bad; if at the time of the "switch" open, no digital multimeter beeps, the internal switch control.
　　(4) Check the insulating housing and the pins
　　The digital multimeter pen then a potentiometer housing, another table pen individually contacting each pin, the resistance should be infinite; otherwise, indicating poor insulation between the shell and the pin.