Transistors are semiconductor devices that are used as amplifiers, as circuit breakers and current connectors (switching), voltage stabilization, and signal modulation. Transistors can function as a kind of electric faucet, which based on the input current (BJT) or input voltage (FET), allows a very accurate flow of electricity from the mains circuit. In general, transistors have 3 terminals, namely Base (B), Emitter (E) and Collector (C). The voltage at one terminal, for example, the emitter, can be used to regulate currents and voltages that are greater than the base input current, namely the output voltage and the collector output current. Transistors are one of the most common semiconductor components found in electronic circuits. It could be said that almost all electronic devices use transistors for various needs in their circuit. The electronic devices in question include televisions, computers, cell phones, audio amplifiers, audio players, video players, game consoles, power supplies and others. In general, transistors have 3 terminals, namely Base (B), Emitter (E) and Collector (C). The voltage at one terminal, for example, the emitter, can be used to regulate currents and voltages that are greater than the base input current, namely the output voltage and the collector output current. Bipolar transistors are also often referred to by the abbreviation BJT which stands for Bipolar Junction Transistor. Bipolar comes from the word "bi" which means "two" and the word "polar" which means "pole" Bipolar transistor have 2 type 1. NPN transistor is a bipolar transistor that uses a small electric current and a positive voltage at the Base terminal to control the flow of currents and voltages that are greater from the Collector to the Emitter. 2. PNP transistors are bipolar transistors that use a small electric current and negative voltage at the Base terminal to control the flow of currents and voltages that are greater from the emitter to the collector. FET (Field Effect Transistor ) This FET is a type of transistor that uses electricity to control its conductivity. What is meant by the electric field here is the electric voltage applied to the Gate (G) terminal to control the flow of current and voltage at the Drain (D) terminal to the Source (S) terminal. This type of FET transistor consists of three types, namely Junction Field Effect Transistor (JFET), Metal Oxide Semiconductor Field Effect Transistor (MOSFET) and This MOSFET also consists of two types of configurations, namely the Depletion MOSFET and the Enhancement MOSFET, each of which is also divided into P-channel (P-channel) and N-channel (N-channel) MOSFETs. MOSFET consists of three terminal legs namely Gate (G), Drain (D) and Source (S). Union Junction Transistor (UJT). Unlike other types of FET, UJT has two Base terminals (B1 and B2) and 1 emitter terminal. UJT is used specifically as a controller (switch) and cannot be used as an amplifier like other types of transistors. Function Transistor As Switching by adjusting the bias of a transistor until the transistor is saturated, a short circuit is obtained between the connector and emitter legs, by taking advantage of this incident the transistor can be used as a switch. As a current amplifier In order to be used as a function of current amplifiers, the transistor must be biased by a constant voltage on its base, so that a constant voltage can be generated at the emitter
