Potentiometer inspection method2021

The quality of the potentiometer is good or bad, we have to pass the inspection to know? Usually it is carried out in the following method.

1. Appearance inspection: check whether the potentiometer shell has scratches, cracks, breakage and other mechanical damage; check whether the potentiometer lead wire is damaged and whether the plug is loose. If the shell has no obvious scratches, cracks, or breakage, and the plug is not loose, it is qualified.

2. Resistance test

1) Use a multimeter to measure the resistance between the two fixed ends of the potentiometer (that is, the resistance between the terminals at both ends), and compare it with the nominal resistance (10KΩ±10%) to see if the two are consistent. Rotate the shaft at the same time, and its value should be fixed. If the resistance is infinite, the potentiometer has been damaged.

2) Measure the contact between the center end and the resistor body, that is, the resistance value between the two ends and the center end. During the measurement, slowly rotate the shaft and pay attention to the reading of the multimeter. Normal situation: as the shaft rotates, the readings increase or decrease evenly and steadily. When the center end slides to the head or end, the resistance value is 0 or nominal Resistance. If there is a phenomenon such as jumping, falling or blocking, it indicates that the movable contact has a fault with poor contact.

3) Judgment: There is a sense of smoothness when the shaft rotates; the resistance value at both ends reaches the nominal resistance value; the sliding resistance value of the potentiometer changes with the rotation of the shaft, the maximum resistance value reaches the nominal resistance value, and the minimum resistance value reaches zero resistance value , Judged as qualified.

3. Performance test

Put the propeller into the water tank, connect the potentiometer to the propeller, turn on the power switch, and slowly rotate the potentiometer shaft repeatedly to observe whether the propeller speeds evenly. When the potentiometer shaft is rotated to both ends, whether the propeller stops or rotates at the maximum speed. If the potentiometer shaft is rotated, the thruster changes speed evenly, and when the potentiometer shaft is rotated to both ends, the thruster stops or the speed is the maximum, it is judged as qualified.

How to check the potentiometer of the switch

(1) Detection of nominal resistance

When measuring, select the appropriate range of the multimeter's resistance range, connect the two test leads between the two fixed pins of the potentiometer, and first measure whether the total resistance of the potentiometer is the same as the nominal resistance. If the measured resistance value is infinite or larger than the nominal resistance value, it means that the potentiometer has been opened or the value of the potentiometer has been damaged.

Then connect the two watch hairs to the center head of the potentiometer and either end of the two fixed ends, and slowly turn the potentiometer handle to rotate it from one extreme position to the other extreme position. The normal potentiometer and the multimeter needle indicate The resistance value of should continuously change from the nominal resistance (or 0ω) to 0ω (or the nominal resistance). During the whole rotation process, the hands of the watch should change steadily without any jumping phenomenon. If in the process of adjusting the resistance value, the watch needle jumps, it means that the potentiometer has a fault with poor contact. The detection method of the sliding potentiometer is the same as this.

(2) Detection with switch potentiometer

For potentiometers with switches, in addition to testing the potentiometer's nominal resistance and contact conditions according to the above methods, it should also be tested whether the switch is normal.

Rotate the potentiometer shaft first to check whether the switch is flexible and whether there is a crisp "click" sound when it is switched on or off. Use the r×1ω gear of the multimeter, and place the two test leads on the two external soldering tabs of the potentiometer switch respectively. Rotate the potentiometer shaft to turn the switch on. The resistance value indicated on the multimeter should change from infinity (∞) to 0ω. Turn off the switch again, the pointer of the multimeter should return from 0ω to “∞”. During the measurement, the potentiometer switch should be turned on and off repeatedly, and the response of each action of the switch should be observed. If the resistance of the switch in the "on" position is not 0ω and the resistance in the "off" position is not infinite, it means that the switch of the potentiometer is damaged.

(3) Detection of dual-shaft potentiometer

Use the appropriate range of the resistance file of the multimeter to measure whether the resistance values ​​of the two sets of potentiometers on the double-connected potentiometer (that is, the resistance value between a and c and the resistance value between a'and c') are the same and whether they are the same as the standard. Said the resistance value matches. Then use wires to short-circuit the potentiometers a and c'and the potentiometers a'and c, and then use a multimeter to measure the resistance between the center heads b and b'. What position, the resistance value between the two points b and b'should be equal to the resistance value between the two points a, c or a', c'(that is, the pointer of the multimeter should always be kept at a, c or a', c' The resistance scale does not move). If the pointer of the multimeter is deflected, it means that the synchronization performance of the potentiometer is poor