What is the difference between NPN and PNP sensor?
PNP and NPN sensors are 3 wire DC devices. The difference is in the type of transistor used in the sensor. The PNP device has 2 control power leads, one connected to positive, the other to negative. However, on an NPN device, the remaining lead from the load must be connected to the positive pole of the power supply.
Electrons are better when compared to holes so (npn) is preferred. Not always … The majority charge carriers in an NPN transistor are electrons and for a PNP transistor, holes. Electrons have greater mobility than holes, thus making the circuit response faster when an NPN transistor is used.
- The main difference between the NPN and PNP transistor is, an NPN transistor turns on when the current flows through the base of the transistor. In this type of transistor, the current flows from the collector (C) to the emitter (E). A PNP transistor turns ON, when there is no current at the base of the transistor.
- Biasing in electronics means establishing predetermined voltages or currents at various points of an electronic circuit for the purpose of establishing proper operating conditions in electronic components. The AC signal applied to them is superposed on this DC bias current or voltage.
- A Bipolar Junction Transistor, or BJT, is a solid-state device in which the current flow between two terminals (the collector and the emitter) is controlled by the amount of current that flows through a third terminal (the base).
Updated: 18th September 2018