Why does the digital multimeter keep beeping?
1. Is the multimeter burned? You can check whether it is normal by measuring the ordinary battery, such as the 5th battery or the 7th battery, with the DC voltage file.
2. If the measured DC voltage is normal, it can be basically determined that there is no problem with the meter head of the multimeter. It should be that the protection element or chip inside was damaged after the high-voltage gear was mistakenly measured with the buzzer gear!
If it is the latter case, as long as the components of the buzzer circuit are checked, generally people with maintenance experience can repair it. If it is the former case, it is best to repair it for warranty.
In the latter case, the key parts to check are diodes (to measure whether they are broken down or open), operational amplifier ICs (as the basis for whether the buzzer is beeping or not, general multimeters use TL062, LM358, or LM2904 and other models). , replace it with the same model)
If the resistance value is very small, it will ring. This file is mainly used for continuity testing. The ringing basically proves that the circuit is connected. If the two test leads are directly short-circuited and the test does not sound (the resistance value is almost zero), it is estimated that the buzzer is broken.
The buzzer file of the digital multimeter is generally used to quickly determine whether the circuit is on or off. The buzzer will beep when the measurement is on. The beeping resistance is generally less than 30~50 ohms, and the minimum resistance of various brands of digital multimeters is different.
