PCB News - How to see the direction of the diode in the pcb board

How to see the direction of the diode in the PCB board

The diode is one of the basic electronic components, and various modulation circuits are mainly composed of it. The principle of judging the quality of the PCB board diode is also very simple. Just use a multimeter to check the resistance file and measure the reverse resistance if it is small. It means that the diode is bad. If the reverse resistance is very large, it means that the diode is good. For the novice Xiaobai, how to see the direction of the diode in the PCB board is a problem. Today I will share a few tips for distinguishing the direction of the diode.
Diode positive and negative identification diagrams usually have a colored end as the cathode and the other end as the anode. Generally, the horizontal bar represents the cathode and the other end is the anode. If you are afraid of misjudgment, you can use a multimeter to measure and measure, to reach the buzzer position (measurement disconnection position), use the positive test lead to select one end, and the other end to use the negative test lead. On, the two test leads will be switched over and tested, it will definitely light up.

Here are several ways to identify the positive and negative poles of the diode:

1. In-line diode: The side with the color ring on the surface of the tube is the negative electrode.

2. Light-emitting diode: The long pin is the positive pole, and the short pin is the negative pole.

3. Light-emitting diodes with the same lead length: Identify by the size of the internal metal piece, the larger side of the metal piece is the negative electrode, and the smaller metal piece is the positive electrode.

4. Diodes whose positive and negative poles cannot be identified by their appearance: use a multimeter to detect, turn the middle knob of the multimeter to "on-off position", and judge the positive and negative poles on the side of the pin based on the reading. When the reading is not "1", the red pen is the positive pole, and when the reading is "1", the black pen is the positive pole.
Diodes whose positive and negative poles cannot be identified by their appearance. The above is about "how to see the direction of the diode in a PCB board". Have you learned how to distinguish the positive and negative poles of a diode?

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