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

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

A diode is a semiconductor device with unidirectional conductivity and can be used for rectification, amplification and cutting in electronic circuits. The connection method of the diode is very important, the correct connection can ensure the normal operation of the circuit, and the wrong connection may cause the circuit to be damaged or not work properly. So, which side of the diode is positive? How should the positive and negative poles be connected?

First, you need to understand the structure of a diode. The diode is composed of a P-type semiconductor and an N-type semiconductor, wherein 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 the property of unidirectional conduction, that is, 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 poles of the diode can be judged. Typically, the anode of a diode is marked with a triangle with an arrow pointing to the N-type semiconductor of the diode. Therefore, the end the arrow points to is the cathode of the diode, and the other end is the anode.

In practical applications, the connection method of the diode is also very simple. When forward rectification is required, the anode of the diode is connected to the positive power supply, and the cathode is connected to the load. At this time, the current can pass through the P-N junction smoothly to achieve forward conduction. And under the reverse voltage, the current cannot pass through the P-N junction, and the diode is in the disconnected state at this moment.

When reverse cut-off is required, the cathode of the diode is connected to the positive power supply, and the anode is connected to the load. At this time, the current cannot pass through the P-N junction to achieve reverse cut-off. Under forward voltage, although current can flow through the P-N junction, due to the reverse characteristics of the diode, the current still cannot pass through, so the diode is in an off state.

It should be noted that when actually connecting the diode, the connection should be as firm and reliable as possible to avoid problems such as poor contact or loose contact. At the same time, when using a diode, you should also pay attention to its voltage and current limit range, so as not to exceed its rated value and cause device damage or unstable operation.

To sum up, the correct connection of the positive and negative poles of the diode can ensure the normal operation of the circuit. In practical applications, it is necessary to select an appropriate connection method according to specific application scenarios, so as to make full use of the unidirectional conduction characteristics of the diode.