Current-sinking devices are PNP sensors, while current-sourcing devices are NPN sensors. A current-sinking input must be connected to a current-source sensor.
NPN stands for Negative-Positive-Negative. The term "switched" refers to the electrically switched side of the regulated load (relay, tiny indicator, PLC input). 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).
During a "on" state, PNP sensors produce a positive signal to your industrial controls input, whereas NPN sensors produce a negative signal. When turned on, NPN, or "sinking" output sensors act in the opposite direction, sinking ground voltage to an input.
A piece of P-type silicon (the base) is sandwiched between two pieces of N-type silicon in an NPN transistor (the collector and emitter). The layers of a PNP transistor are reversed in type. The schematic symbols for NPN and PNP transistors are extremely similar. The direction of the arrow on the emitter is the sole change.
Electrons make up the bulk of charge carriers in an NPN transistor, while holes make up the majority of charge carriers in a PNP transistor. The mobility of electrons is greater than that of holes. NPN transistors are therefore preferred over PNP transistors.
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Pavan valmik koli
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Hi sir can you please let me know how to get this leader logic software?
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Vijaykumar
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Sir I have dout u can solve my problem
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Durgesh
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I finished PLC Course at Minimum time, Videos content is to good
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Jasbir
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I have pay this course amout 16 oct can u tell me how many days for delivery my certificate
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Faiz Siddique
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Dear You make a little mistake in NPN transistor current flow from Emitter to Collector , not form collector to Emitter please correct it
S
Sagar
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the unit of voltage is volts please change it (9:07)the classes are absolutely good
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