Triode, also known as bipolar transistor or transistor, is a semiconductor device for controlling current. It can amplify weak signals into large-amplitude electrical signals, and can even be used as a contactless switch. In this paper, the current distribution in the transistor will be discussed in depth to help readers better understand this core component.

Current distribution relation

The current distribution in triode is very interesting. Emitter current is the sum of collector current and base current, and it is the current distribution relationship among three electrodes in triode.

Core component

As the core component of electronic circuit, transistor has the function of current amplification. It is to make two very close PN junctions on a semiconductor substrate and divide the whole semiconductor into three parts: the base region in the middle, the emitter region and the collector region on both sides. There are two transistor arrangements: PNP and NPN.

current amplification

Transistors have the function of current amplification, which can amplify weak signals into electrical signals with large amplitude. This function makes triode one of the indispensable components in electronic circuits.

contactless switch

Triode can be used as contactless switch because of its current control characteristics. When the control current of the transistor reaches a certain value, it can control the switching operation of large current.