Transistor as a Switch Summary. When using the bipolar transistor as a switch they must be either “fully-OFF” or “fully-ON”. Some of the applications use a power transistor as switching device, at that time it may necessary to use another signal level transistor to drive the high power transistor. The load can be either the led or the resistor, load depends based on the requirement. This PN junction controls the flow of current across the junction. In today’s tutorial, we will have a look at Transistor as a Switch. When we combine a P-type and N-Type semiconductor materials with each other, a junction is formed between them. Tran… A transistor is a three-terminal semiconductor device which can be used for switching applications, amplification of weak signals and in quantities of thousands and millions of transistors are interconnected and embedded into a tiny integrated circuit/chip, which makes computer memories. Then to summarise when using a Transistor as a Switch the following conditions apply: Transistor switches can be used to switch and control lamps, relays or even motors. This type of LED has a voltage drop of 1.8 V and is rated at a maximum current of 20 mA. Once the transistor is in ON condition the current generated tends to flow from source to the load. The transistor is a 3 pin semiconductor module used for different amplifier and switching circuits.It was created by William Shockley (who was … A Transistor switch, which is used for opening or closing of a circuit, that means the transi… In Electronics Transistor is widely used as the switching purpose . The operating conditions of the P-N-P and N-P-N transistor differ in the application positive or the negative voltages. But this junction breaks by applying a proper biasing voltage across transistor pins. This junction is also known as a PN junction or a transistor. Active Region – the transistor operates as an amplifier Saturation – the transistor is “Fully-ON” operating as a switch and Cut-off – the transistor is “Fully-OFF” operating as a switch and BJT IS CURRENT CONTROLLED. The transistor was invented by William Shockley in 1947. Look at this circuit component by component: LED: This is a standard 5 mm red LED. We design this digital switch by connecting P-type and N-Type semiconductor materials with each other. Both NPN and PNP transistors can be used as switches. A transistor is used for switching operation for opening or closing of a circuit. Hello friends, I hope you all are doing great. P-N-P Transistor as a Switch. This is a schematic diagram for a circuit that uses an NPN transistor as a switch that turns an LED on or off. This type solid state switching offers significant reliability and lower cost as compared with conventional relays.