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.

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.

What is the use of BC557 transistor?

BC557 is a general-purpose transistor, used like an amplifier or a switch in electronic circuits. Its hFE ratings of this transistor range from 125 to 800 to make the transistor ideal by using like an amplifier within electronic circuits like audio signal amplification.

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.

Can I use NPN transistor as PNP?

Answer: NPN and PNP transistors are interchangeable if you remember one simple rule: A bipolar transistor is essentially two back-to-back diodes with the base being the common connection.

How do PNP transistor?

Definition: The PNP transistor is a type of transistor in which one n-type material is doped with two p-type materials. When a small current flow through the base of the PNP transistor, it turns on. The current in a PNP transistor flows from the emitter to the collector.

What is BD140 transistor?

BD140 is a medium power bipolar junction transistor that is mainly used for switching and amplification purpose. It belongs to the PNP transistor category and comes in the TO-126 package. It is made up of silicon material with collector current 1.5A which indicates it can support loads under 1.5A.

How do you trigger a PNP transistor?

First of all, to turn on the PNP transistor, you need the voltage on the base to be lower than the emitter. For a simple circuit like this, it’s common to connect the emitter to the plus from your power source. This way, you know what voltage you have on the emitter.

Is PNP and NPN same?

As they are normally referred, PNP and NPN sensors are both supplied with positive and negative power leads, then produce a signal to indicate an “on” state. PNP sensors produce a positive output to your industrial controls input, while NPN sensors produce a negative signal during an “on” state.

What is the symbol of PNP transistor?

PNP vs NPN Transistor

Is PNP a transistor?

The PNP transistor is a type of transistor in which one n-type material is doped with two p-type materials. It is a device that is controlled by the current. Both the emitter and collector currents were controlled by the small amount of base current. Two crystal diodes are connected back-to-back in the PNP transistor.