Precautions for measuring new energy vehicle testing multimeter
(1) The new energy vehicle testing multimeter should have a sufficiently large internal resistance, which should be at least 10 times greater than the resistance of the tested circuit to avoid causing significant measurement errors.
(2) The pen or probe should be equipped with anti slip measures. Any momentary short circuit can easily damage the integrated circuit. The following methods can be adopted to prevent the pen from slipping: take a section of bicycle valve core and cover it on the pen tip, and grow the pen tip about 0.5 millimeters. This not only ensures good contact between the pen tip and the tested point, but also effectively prevents slipping, even if it touches adjacent points, it will not short-circuit.
(3) When the voltage of a certain pin does not match the normal value, it should be analyzed based on whether the voltage of that pin has a significant impact on the normal operation of the integrated circuit and the corresponding changes in the voltage of other pins in order to determine the quality of the integrated circuit.
(4) The voltage of integrated circuit pins is affected by peripheral components. When there is leakage, short circuit, open circuit, or variation in the peripheral components, or when the peripheral circuit is connected to a variable resistance potentiometer, the position of the potentiometer sliding arm is different, which will cause the pin voltage to change.
(5) If the voltage of each pin in the integrated circuit is normal, it is generally considered that the integrated circuit is normal; If the voltage of some pins in the integrated circuit is abnormal, it should be started from a point that deviates significantly from the normal value to check for any faults in the peripheral components. If there are no faults, the integrated circuit is likely to be damaged.
(6) For dynamic receiving devices such as televisions, the voltage at each pin of the integrated circuit varies with or without a signal. If it is found that the pin voltage should not change but changes greatly, and does not change with the signal size and different positions of adjustable components, it can be determined that the integrated circuit is damaged.
(7) For devices with multiple working modes, the voltage of each pin of the integrated circuit varies under different working modes.
