How does a multimeter measure short circuits and open circuits?
A multimeter is an essential "hardcore" tool for friends engaged in electronics, electrical engineering, and maintenance related fields. It has very powerful functions and can be used to measure AC voltage, DC voltage, AC current, DC current, resistance, capacitance, diode, transistor, temperature, etc. For example, when testing and debugging products, we need to use a multimeter to assist in finding problems.
When a product malfunctions, I usually measure the input and output voltages using the voltage range to determine if the power supply circuit is functioning properly. Abnormal voltage often indicates a short circuit or open circuit.
Buzzer gear test for short circuit and open circuit
A digital multimeter usually has a buzzer mode, which will sound "BI" when connected, which is very intuitive and does not require staring at the multimeter.
When measuring two positions that should not be connected, if a "BI" sound is emitted, it indicates a short circuit; When measuring two positions that should be connected, but there is no "BI" sound, it indicates that there is a circuit breaker;
If your multimeter does not have a buzzer mode, you can also use a resistance mode to determine if there is a short circuit or open circuit according to the method of measuring resistance. If the resistance becomes very small, only a few ohms, or even a few tenths of an ohm, it indicates a short circuit; If the resistance value cannot be measured or is significantly high, it indicates that there is an open circuit.
