How to repair pointer multimeter buzzer does not sound
For people commonly used MF47 pointer multimeter, part of the model with path detection. That is, a buzzer is connected in series in the circuit. Passage buzzer detection; this gear in the resistance block R * 1Ω next to the block.
This gear is mainly used to quickly determine the circuit on, off, in the measurement of the case of through the buzzer will immediately emit a beeping sound, do not need to use the eyes to see the multimeter's needle indication, that is, you can understand the circuit of the on-off situation.
First of all, it is the same as the resistor need to zero the instrument, this time the buzzer works about 1kHz long beep, can be measured. When the resistance value of the measured circuit is lower than about 10 Ω, the buzzer will beep sound. It should be noted that the size of the buzzer sound and the measured circuit resistance value inversely proportional to the relationship (i.e., the greater the resistance value of the circuit, the buzzer sounds smaller), when the dial pointer value of about R * 3 (reference value).
For this pointer multimeter, buzzer damage is mainly caused by the user error dial in the buzzer gear to measure AC voltage and damage.
There are two types of buzzers, one is a piezoelectric ceramic buzzer and the other is an electromagnetic buzzer. Different multimeters will use different buzzers. A piezo ceramic buzzer has a sound but a very high resistance when measured with a multimeter, whereas an electromagnetic buzzer has a certain resistance and emits a beeping sound when measured with a multimeter.
