How to detect the adjustable encoder quality stand or fall?

Adjustable adjustable encoder is a kind of commonly used electronic components, derived from variable resistor, it development, by a resistor and a rotating or sliding system composition, the movable arm with the brush on the resistor body sliding, can continuously change the resistance value between movable arm and the two ends. When we purchase the adjustable encoder, receiving to detect it, and see whether there is the occurrence of adverse conditions, then, how to detect the adjustable encoder quality stand or fall? We can from the following several flash for testing. (1) appearance inspection for fixed resistor first check mark clear, paint is in good condition, no burning, no scar, no cracks, no corrosion, resistance body closely contact with pins, etc. Should also check for adjustable encoder shaft flexible, elastic, comfortable feel. Have to check the encoder switch action is normal. Diction multimeter test (1) fixed resistance test block for resistance measurement with multimeter of electricity, for measuring resistance of different resistance to choose different times by blocking multimeter. For pointer multimeter, due to the readings is nonlinear electric block, the greater the resistance, the readings more closely, so choose the appropriate range, whose hands deflection Angle is big, should be instructed to 1/3 to 2/3 full range, more accurate readings. If measured value exceeds range of the error of the resistance, resistance is infinite, resistance to 0 or unstable resistance, suggests that the resistor has been bad. Pay attention to in the measurement of resistance of the hand do not contact with the two resistor lead JiaoXiang, such meetings make hand shows the resistance of the measured resistance in parallel, and affect the measuring accuracy. In addition, cannot be charged case with multimeter resistor of resistance in an electric barrier detection circuit. On-line inspection shall, first of all, without electricity, will the resistance from the circuit break out again, and then measured. (2) the volume adjustable encoder fuse resistors and sensitive resistance testing fuse resistance value generally only a few to dozens of European, if measured value is infinite, has a fuse. Of on-line detection of fuse resistors can be good or bad, measured its both ends of the voltage, if the end for the power supply voltage, the voltage of 0 v, fuse resistors have fuse. Sensitive resistor sort is more, in the case of thermistor, and positive temperature coefficient and negative temperature coefficient thermistor. For the positive temperature ( PTC(列车自动控制系统) Thermistor, general resistance at room temperature is not big, in the measurement using the soldering iron to resistance, heat resistance should be increased at this moment, show that the resistance is normal, if no change shows that element damage, negative temperature of thermistor, on the other hand. Photosensitive resistance in the absence of light, With the hand or cover the light) Multimeter to measure resistance under the condition of big, whose hands indicator light resistance value are significantly reduced. If no change, the damage of components. (3) variable resistance and encoder test first measured between two fixed end resistance is normal, for infinite or zero, or with nominal large difference, exceed range of allowable error, all that has been damaged; Resistance value is normal, then slide multimeter a pens and answer the encoder side, the other pens and encoder ( Adjustable resistance) Any of the fixed end, varied slowly rotating shaft handle, observe whether the clock is smooth, when from one end of the screw to the other end, resistance from zero the change to the nominal value ( Or the opposite) And no jump or the phenomenon such as jitter, explain the encoder is normal, if in the process of spinning jump or dithering phenomenon, that sliding resistance is to the poor contact. Shanghai electronic 27 years, specializing in the production of adjustable encoder encoder models complete, the production of various types of adjustable encoder: rotary encoder, switch, encoders, straight and smooth encoder, rocker encoder, with single and double motor encoder and various style encoder, stable quality, trustworthy, looking for adjustable encoder for electronic manufacturers.