How to use a multimeter to test electronic components
Multimeters are also called multiplex meters, multimeters, three-meters, multi-meters, etc. They are indispensable measuring instruments in power electronics and other sectors. They generally measure voltage, current, and resistance as their main purpose. It is a multi-functional, multi-range measuring instrument. Generally, multimeters can measure DC current, DC voltage, AC current, AC voltage, resistance and audio level, etc. Some can also measure AC current, capacitance, inductance and semiconductor Some parameters etc.
1. Test resistance
SMD resistors are generally printed with the identification characters of the resistance value. Use the resistance file of a multimeter to test and compare the marked values to know whether it is normal.
2. Test capacitance
Many digital multimeters have capacitance test gears. Short-circuit and discharge the capacitor first, adjust to the capacitance test gear, and then connect the capacitor to be tested to the two dedicated test ports for the capacitor, and then you can read the capacity. If you only judge the capacitance roughly Good or bad, use the resistance gear or buzzer gear to test, the capacitance should not measure the resistance value or the resistance changes from small to large and then to infinite, it is normal.
3. Test the diode
According to the unidirectional conductivity of the diode, use the buzzer to connect the red and black pens randomly. If it is on, the red pen is connected to the anode of the diode, and the black pen is connected to the negative electrode. In this way, the test twice can be judged as normal, otherwise it is abnormal. The specific operation of the triode is the same as the diode
4. Test the inductance
Some multimeters have an inductance test file that can test the inductance. The method is similar to that of the test capacitor. If there is no inductance test function, you can only use the buzzer or resistance file to test whether the inductance is open. If the inductance is short-circuited, it cannot be determined. There is a dedicated capacitance and inductance meter for testing, and the LCR bridge is best used.