Can a PNP transistor be used as a switch?
Both NPN and PNP transistors can be used as switches. 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.
Can I replace PNP with NPN?
So for a PNP transistor to conduct the Emitter is always more positive with respect to both the Base and the Collector. Generally, the PNP transistor can replace NPN transistors in most electronic circuits, the only difference is the polarities of the voltages, and the directions of the current flow.
How can a transistor be used as a switch?
With a zero signal applied to the Base of the transistor it turns “OFF” acting like an open switch and zero collector current flows. With a positive signal applied to the Base of the transistor it turns “ON” acting like a closed switch and maximum circuit current flows through the device.
Which is the fastest switching device?
MOSFET
Amongst BJT, MOSFET, JEFT and Triode, MOSFET is the fastest switching device because of its quickest response.
When did William Shockley invent the transistor?
The transistor is a 3 pin semiconductor module used for different amplifier and switching circuits. It was created by William Shockley (who was a physicist of United States of America) in 1947. It also used in different engineering projects and circuitry.
How are transistors used in solid state switching?
This type of switching application is used for controlling LEDs, motors, lamps, solenoids, etc. A transistor can be used for switching operation for opening or closing of a circuit. This type solid state switching offers significant reliability and lower cost when compared to conventional relays.
How does the base and emitter of a transistor work?
The base and emitter of transistor working as a controller that decides open and closed condition of switch. For closed the switch the battery is connected between base and emitter terminals. This source provides large amount of base current due to that collector current flows in the collector and emitter circuitry.
Why are transistor switches used in logic gates?
However, high power devices such as motors, solenoids or lamps, often require more power than that supplied by an ordinary logic gate so transistor switches are used.