How to judge the capacitor is good or bad?
Due to the amplification of the composite transistor, the measured capacitance of the charge and discharge process to be amplified, so that the multimeter pointer increase the amplitude, so easy to observe. It should be noted that: in the test operation, especially in the measurement of small capacity capacitance, it is necessary to repeatedly change the measured capacitance of the pin contact A, B two points, in order to clearly see the multimeter pointer swing.
Multimeter selection R × 1k block. Both triodes have a beta value of 100 or more and a small penetration current. Can choose 3DG6 and other types of silicon transistors composed of composite pipe. The multimeter's red and black test leads are connected to the emitter e and collector c of the composite tube, respectively.
Measurement, the choice of multimeter R × 10k block, with two test leads were any then the capacitor of the two pins, the resistance should be infinite. If the measured resistance (pointer to the right swing) is zero, then the capacitor leakage damage or internal breakdown.
10pF below the fixed capacitor capacity is too small, with a multimeter to measure, only qualitative check whether there is leakage, internal short circuit or breakdown phenomenon.
