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What two things can a transistor do?
A transistor is a miniature electronic component that can do two different jobs. It can work either as an amplifier or a switch: When it works as an amplifier, it takes in a tiny electric current at one end (an input current) and produces a much bigger electric current (an output current) at the other.
What are the two main transistors?
There are two main types of transistor: bipolar junction transistors (BJTs) and field effect transistors (FETs).
Where is a transistor controlled?
Transistor Switch. Our control input flows into the base, the output is tied to the collector, and the emitter is kept at a fixed voltage. While a normal switch would require an actuator to be physically flipped, this switch is controlled by the voltage at the base pin.
How much current can transistor handle?
It’s usually around 100, but can range from 50 to 200…even 2000, depending on which transistor you’re using and how much current is running through it. If your transistor had a β of 100, for example, that’d mean an input current of 1mA into the base could produce 100mA current through the collector.
How is a transistor used to control a microcontroller?
These pins are meant to send control signals, not to act as power supplies. The most common way to control another direct current device from a microcontroller is to use a transistor. Transistors allow you to control the flow of a high-current circuit from a low-current source.
How is a transistor used to control high current loads?
It’s designed for switching high-current loads. It has three connections, the base, the collector, and the emitter. The base is connected to the microcontroller’s output through a resistor. The high-current load (i.e. the motor or light) is attached to its power source, and then to the collector of the transistor.
How does the base of a transistor control current?
The base still controls current flow, but that current flows in the opposite direction — from emitter to collector. Instead of electrons, the emitter emits “holes” (a conceptual absence of electrons) which are collected by the collector. The transistor is kind of like an electron valve.
How are current and voltage in a transistor modeled?
Many transistor situations can be modeled as though a small controlling current or voltage signal at one terminal can control a much larger current or voltage at another terminal. Voltage and currentare the two primary state variables in an electronic system.