- Potentiometer damage discrimination detection
First, measure the nominal resistance of the potentiometer. Use the ohm range of a multimeter to measure the “1” and “3” ends (with the “2” end as the movable contact), and the reading should be the nominal value of the potentiometer. If the pointer of the multimeter does not move, the resistance value does not move, or the resistance value differs significantly, it indicates that the potentiometer is damaged.
Check again whether the contact between the movable arm of the potentiometer and the resistor is good. Measure the ends of “1”, “2” or “2” and “3” with the ohm range of a multimeter. Rotate the potentiometer shaft counterclockwise to a position close to “off”, and the resistance should be as small as possible. Then slowly rotate the shaft clockwise, and the resistance should gradually increase. When rotated to the extreme position, the resistance value should be close to the nominal value of the potentiometer. During the rotation of the potentiometer shaft handle, the multimeter pointer may have a jumping phenomenon, indicating poor contact at the movable touch point.
- Measure the leakage resistance of large capacity capacitors
Place the 500 type multimeter in the R×10 or R×100 range. When the pointer points to the maximum value, immediately switch to the R×1k range for measurement. The pointer will stabilize in a short period of time, allowing the leakage resistance value to be read.
