How to repair the analog multimeter buzzer that does not sound
For the commonly used MF47 pointer multimeter, some models come with path detection. That is to say, a buzzer is connected in series in the circuit. Path buzzer detection; This gear is next to the resistance gear R * 1 Ω.
This gear is mainly used to quickly determine the on/off status of the circuit. When it is measured to be on, the buzzer will immediately emit a beep sound. It is not necessary to look at the needle indication of the multimeter with your eyes to understand the on/off status of the circuit.
Firstly, like the resistor gear, the instrument needs to be zeroed. At this time, the buzzer will emit a long beep sound of about 1kHz when it is working, and the measurement can be carried out. When the resistance value of the measured circuit is below about 10 Ω, the buzzer will emit a buzzing sound. It should be noted that the sound intensity of the buzzer is inversely proportional to the resistance value in the measured circuit (i.e. the larger the resistance value in the circuit, the smaller the sound emitted by the buzzer). At this time, the dial pointer value is approximately R * 3 (reference value).
For this type of pointer multimeter, the damage to the buzzer is mainly caused by the user mistakenly setting the buzzer gear to measure AC voltage, resulting in damage. In order to provide the questioner with a clear understanding of repairing the damaged buzzer.
There are two types of buzzers, one is a piezoelectric ceramic buzzer blade, and the other is an electromagnetic buzzer. Different multimeters may use different buzzers. The piezoelectric ceramic buzzer is measured with a multimeter and produces sound but has a very high resistance value, while the electromagnetic buzzer has a certain resistance value and emits a buzzing sound when measured with a multimeter.
