Points for attention when measuring new energy vehicle testing multimeters
(1) The new energy vehicle detection multimeter must have a large enough internal resistance, at least 10 times greater than the resistance of the circuit under test, so as not to cause large measurement errors.
(2) Anti-slip measures should be taken for the test leads or probes. Any momentary short circuit can easily damage the integrated circuit. The following methods can be adopted to prevent the test pen from sliding: take a bicycle valve core and put it on the test pen tip, and grow the test pen tip by about 0.5mm, which can not only make the test pen tip in good contact with the tested point, but also effectively prevent slipping. It will not be short-circuited even if it hits a neighboring point.
(3) When the measured voltage of a certain pin does not match the normal value, it should be analyzed according to whether the pin voltage has an important impact on the normal operation of the integrated circuit and the corresponding changes in the voltage of other pins, so as to judge whether the integrated circuit is good or bad .
(4) IC pin voltage will be affected by peripheral components. When leakage, short circuit, open circuit or value change occurs in peripheral components, or the peripheral circuit is connected to a potentiometer with variable resistance, the position of the sliding arm of the potentiometer is different, which will cause the pin voltage to change.
(5) If the voltage of each pin of the integrated circuit is normal, it is generally considered that the integrated circuit is normal; if the voltage of some pins of the integrated circuit is abnormal, you should start from the point where the deviation from the normal value is the largest, and check whether the peripheral components are faulty. The integrated circuit is likely to be damaged.
(6) For a dynamic receiving device, such as a TV, the voltage of each pin of the integrated circuit is different when there is a signal or not. If it is found that the pin voltage should not change but changes greatly, and that which should change with the signal size and the different positions of the adjustable element does not change, 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 is also different under different working modes.
