How PNP Transistor Works as a Switch?
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- Опубликовано: 30 авг 2019
- In this video I highlight how a bipolar junction PNP transistor operates when being used as a switch. This video demonstrates a simple and practical look that will help you understand what a PNP (Sourcing) transistor does and how it energizes a load.
Industrial electricians are dealing constantly with proximity switches that are configured as either PNP or NPN, this will also help explain which one you will need. PNP Transistors "Source" positive voltage to a load, or a PLC input. They pair with a "Sinking" or NPN PLC input card.
If an electronic assembly or system is noted as configured for PNP, its outputs source positive voltage, and inputs expect positive voltage to energize them.
Thank you very much. The book said "make sure you understand why?" But didn't explain shit lol, you solved my question and now I can move on to the next circuit. Appreciate it 👍🎉
This cleared up so much. Now I understand why it helps when reverse bias is needed.
@colinmitchell7760 Do you see the date last posted? Aside from that, I welcome constructive criticism, but they have to be constructive. Anything outside of that is just starting $#"[, and I will not engage in this madness over a two year old post. I'm glad you're so gifted you pointed out a slight flaw in my statement from years of learning the basics, but seriously. No bro. Not doing this.
Nice Job... Real world examples in layman terms.
Very useful tutorial 👍, please keep going to post such interesting tutorial. Thanks
Master in Layman's terms is a true master in their craft. Awesome. thank you.
#Philippines
thank you very much, thanks to the comparison with the relay, I understand much better!
Thsnks for you explanation hope to continue
Nice brass tacks explanation
Thank you for your lesson sir
Thanks this helped me a lot
Thanks, good video
Thank you friend.
Probably the best video on RUclips in terms of real world transistor application. Thank you.
That said, Instead of floating the Base of the transistor to break the Emitter/Collector path, wouldn't setting the Base to the Emitter potential generate the same result?
Thank you for the good review. You are correct. If base and emitter are at the same potential, the collector emitter junction will block current flow.
Thank you so much
IAM the first one thump up . Keep it up . I like the way you give the information and you make it simple
Tenkyu. veri gut .
Nice information 👉❤❤❤🙏🙏🙏👍👍💕💕
Is there a way to control a solid state relay using a pnp controler? I have a pressure switch with a pnp output and would like it to control an alarm when the air pressure drops below a set point. Thanks very much!
Awesome
Thanks
I have worked designing tons of circuits in America. And the typical convention is to use NPN transistors for nearly everything. PNPs just aren't used that much. But I guess it depends on what you are designing. JMHO
Thank you. The video is geared more toward industrial sensors and switches, and supporting the idea that they are usually configured to provide a positive rail output when active (if manufactured in the US.)
You speak about COMPLEMENTARY transistors. Is there a discrete complementary transistor, or are we talking transistor pairs?
Also, why no use of pullup resistor on the base?
thanks very informing
so is this a pull down or pull up. i watched one video and he said it is a pull up , the other on said it is pull down.
i have a question regarding a pnp transistor switching a parallel mosfet in xcortech 304 for airsoft replica, is it better than using mosfets only? i wanna try to copy the schematics using to220 package pnp and irlb3034pbf mosfet if its going to run better than 3034 alone
So If I want to duplicate a reed switch using a hall sensor such as A3144 for high current, should I then use PNP MOSFET? Meaning that when the magnet passes by the sensor and its output is hardly much and it is hooked up to the gate of the MOSFET, it will cause the MOSFET to turn on and current flow through it, and when no magnet passes by the sensor, there is no voltage at all to the gate of the MOSFET and that causes the MOSFET not to close or it is off or it floats or whatever you want to call it. Is this what is happening? And if one uses NPN MOSFET, then it will be the opposite, as the magnet passes by the hall instead of allowing current going through the MOSFET, the current stops and if there is no voltage at the output of the sensor, no magnet by it, the MOSFET is on. In other words, the NPN MOSFET is on by default. While the PNP MOSFET is off by default in a sense. I s this correct?
I like to make a fidget spinner motor with a magnet on each of its three arms and use the hall and a transistor to energize a coil so every time the magnet passes by the sensor the coil is energized and pushes the magnets and is de-energized when the magnet is not by the sensor. I assume PNP MOSFET must be the right choice according to what I see here unless I have it wrong.
You sound like David Duchovny. The truth is out there!
Can you explain what the resistor at the base is doing? How is it lowering the current to the load if current takes the path of least resistance?
Excellent question. The base - emitter junction is like a diode. And almost always, diodes need a resistor in series otherwise they will burn up. So somewhere in the base to emitter circuit, a resistor is needed. They put it on the base side, because they don't want it to affect the flow of current in The collector.
You are limiting the current basically. That's all
Make sure what you hv written on z board is visible
So if I apply +voltage to base the transitor will turn off right?
Positive voltage, compared to the emitter.
I need info about mosfet why they brake down in 60v in linear region even they consider to have brake down in 200v . Even I use the data sheet required power / volt / current . They just short out because they can't handle any longer the linear action more than a couple of seconds . So I only see mosfet is good for switching application
Many different things to consider. All transistors dissipate heat in the linear region (current, and voltage drop at the same time). Without seeing specific examples, I would assume you are allowing too much current (DS) while at this 60 volts.
Yes . Example I have a power DC load test max volt 100v max current 20A max power 360W . The mosfet just brake down in 60v 5A with less than 5 second even the temperature not yet go to 70 . But in 12v DC I can go even to 28A with out problem and even the temperature not max than 80c even up to 5 min . I think you know the DC load testing. IAM trying to find a mosfet can work on my universal DC load test for testing 80v 20A 1600w ( powersupply )
Which MOSFET are you using?
Soo many ( too many models ) now i buy IXTX90N25L2 to test it
Do you think that I have a problem with the mosfet driver ? Or shunt current ohm feed back ? But this 2 are already devitalized by microcontroller .
Why are you saying the collector floats when the transistor is off? I think it should be ground since there is no current through the load. That means means voltage across the load is zero, and the collector voltage will equal to what the load is connected which is ground.
The collector can be thought of as ground only because of the load, and only if the load is low impedance. If the load is high impedance or has reactivate characteristics, it takes time to stabilize to a ground potential. Try hooking that pnp output to a high impedance input and you will see it doesn't work as expected when turned off. You would need a low impedance circuit to quickly pull the collector point back to ground. Low impedance loads like coils and relays will appear to work like you described.
So for people who just want working knowledge to use them. Connect base to ground, and it shits itself... and you need the polarities to be right on the other 2 pins.
I just did not understand why did you put a number 3 at the middle of the transistor???
Sorry that was supposed to be a "B" for base.
Sorry I am just a little lost. From everything prior to this video, I understood that you source a low input current to the base of an NPN transistor. As for a PNP, you sink through the base by having a lower potential relative to the emitter. I understand that when you are not using conventional current the opposite is true, but I was told in lectures from my professors that electrical engineers(EE's) use conventional and physicists use true flow(Hole vs electron flow). Therefore, I would imagine that you would use a PNP transistor if you were dealing with low level logic.
You are correct. The PNP transistor is the "sourcing" portion of the circuit. So to turn it on you must "sink" the current from the emitter, through the base. Conventional flow. Same goes for the load, the PNP sources the current and the rest of the circuit sinks the current through the collector and load.
Differentiate between NPN and PNP transistors. According to you which one is going to switch faster.
؟؟؟؟ 💔 💔 💔 💔 💔
switching speed is not related to type of transistor (PNP or NPN wise).
Thanks this helped me a lot