What are PNP transistors used for?
PNP transistors are used to source current, i.e. current flows out of the collector. PNP transistors are used as switches. These are used in the amplifying circuits. PNP transistors are used when we need to turnoff something by push a button.
How can I use PNP as a switch?
For a PNP transistor, the Emitter potential must be positive with respect to the Base. Then the transistor operates as a “single-pole single-throw” (SPST) solid state 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.
Can PNP replace NPN?
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. PNP transistors can also be used as switching devices and an example of a PNP transistor switch is shown below.
What is PNP wiring?
PNP = Switched Positive. NPN = Switched Negative. “Switched” refers to which side of the controlled load (relay, small indicator, PLC input) is being switched electrically. Either the load is connected to Negative and the Positive is switched (PNP), or the load is connected to Positive and the Negative is switched (NPN …
Can PNP be used as NPN?
How do you use a transistor as a switch?
Some of the basic Applications of Transistor as a Switch. In a transistor, unless a current flows in the base circuit, there is no current can flow in the collector circuit. This property will allow a transistor to be used as a switch. The transistor can be switched ON or OFF by changing the base.
How does a PNP transistor work?
PNP Transistor. A PNP transistor receives positive voltage at the emitter terminal. The positive voltage to the emitter allows current to flow from the emitter to the collector, given that there is negative current to the base (current flowing out of the base to ground).
How does NPN transistor work?
The NPN transistor is designed to pass electrons from the emitter to the collector (so conventional current flows from collector to emitter). The emitter “emits” electrons into the base, which controls the number of electrons the emitter emits.
What is switching transistor?
A transistor is used for switching operation for opening or closing of a circuit. This type solid state switching offers significant reliability and lower cost as compared with conventional relays. Both NPN and PNP transistors can be used as switches.