Which side of the diode is the positive terminal? How to connect the positive and negative poles

Which side of the diode is the positive terminal? How to connect the positive and negative poles

A diode is a semiconductor device with unidirectional conductivity, which can be used for rectification, amplification, and cutting in electronic circuits. The connection method of diodes is very important. Proper connection can ensure the normal operation of the circuit, while incorrect connection may cause damage or malfunction of the circuit. So, which side of the diode is the positive terminal? How should the positive and negative poles be connected?

Firstly, it is necessary to understand the structure of diodes. A diode is composed of a P-type semiconductor and an N-type semiconductor, where the doping concentration of the P-type semiconductor is higher than that of the N-type semiconductor, and the two are connected through a P-N junction. The P-N junction has unidirectional conductivity, which means that under forward voltage, current can flow through the P-N junction, but under reverse voltage, current cannot flow through the P-N junction.

Based on this structural characteristic, the positive and negative terminals of the diode can be determined. Normally, the positive pole mark of a diode is represented by a triangle with an arrow pointing towards the N-type semiconductor of the diode. Therefore, the end pointed by the arrow is the negative terminal of the diode, while the other end is the positive terminal.

In practical applications, the connection method of diodes is also very simple. When forward rectification is required, the positive terminal of the diode is connected to the positive power supply and the negative terminal is connected to the load. At this time, the current can smoothly pass through the P-N junction, achieving forward conduction. Under reverse voltage, current cannot pass through the P-N junction, and the diode is in an open state.

When reverse cutoff is required, the negative terminal of the diode is connected to the positive power supply, and the positive terminal is connected to the load. At this time, the current cannot pass through the P-N junction, achieving reverse cutoff. Under forward voltage, although current can flow through the P-N junction, due to the reverse characteristic of the diode, current still cannot pass through, so the diode is in an open state.

It should be noted that when connecting diodes in practice, efforts should be made to ensure a firm and reliable connection, avoiding problems such as poor or loose contact. At the same time, when using diodes, attention should also be paid to the voltage and current limits to avoid exceeding their rated values and causing device damage or unstable operation.

In summary, correctly connecting the positive and negative terminals of the diode can ensure the normal operation of the circuit. In practical applications, it is necessary to choose the appropriate connection method based on the specific application scenario to fully utilize the unidirectional conductivity of diodes.