How to use the diode file of the multimeter
Use the diode gear of the digital multimeter, and insert the red test lead into the VΩ hole and the black test lead into the COM hole. We know that in the digital multimeter, the red test lead touches the positive pole of the internal battery, and the black test lead touches the negative pole of the internal battery. Battery negative black test lead contact
The positive pole of the internal battery, touch the red pen of the digital multimeter to the positive pole of the diode, and the black pen to the negative pole of the diode, (to measure the forward resistance value) the normal value is 300-600Ω, then touch the red pen to the negative pole of the diode, and the black pen to the positive pole of the diode (to measure the reverse resistance value), the normal value is "1". If the two measurements show 001 or 000 and the buzzer sounds, it means that the diode has broken down. If the forward and reverse resistance values of the two measurements are both "1", it means that the diode is open. If The two measured values are similar, indicating that the quality of the tube is very poor, the reverse resistance value must be "1" or above 1000, and the forward resistance value must be 300-600Ω. Then the diode is fine.
Diode, (English: Diode), among electronic components, a device with two electrodes that only allows current to flow in a single direction. Many uses apply its rectification function. The varactor diode (VaricapDiode) is used as an electronic adjustable capacitor. The current directionality of most diodes is usually called "rectifying" function. The most common function of a diode is to only allow current to pass in a single direction (called forward bias), and to block it in the reverse direction.
(called reverse bias). So a diode can be thought of as the electronic version of a check valve.
1. Digital multimeter: set the gear to Ω, connect the red test lead to the positive pole of the diode, the black test lead to the negative pole of the diode, and the meter head shows the path (with a certain resistance value); on the contrary, connect the black test lead to the positive pole of the diode, and the red test lead Connect to the negative pole of the diode, and the meter shows open circuit (the resistance value is very large), indicating that the diode is good.
2. Mechanical multimeter: set the gear to Ω, connect the black test lead to the positive pole of the diode, the red test lead to the negative pole of the diode, and the meter head shows the path (with a certain resistance value); on the contrary, connect the red test lead to the positive pole of the diode, and the black test lead Connect to the negative pole of the diode, and the meter shows open circuit (the resistance value is very large), indicating that the diode is good.
3. The red test lead of the digital multimeter is connected to the positive pole of the battery in the meter, while the mechanical multimeter is just the opposite, so it is necessary to correctly distinguish the red and black test leads before measuring.
4. During the measurement, if both forward and reverse directions show a path, or both show an open circuit, it means that the diode has been damaged.
