How to Use a MOSFET as a Switch
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- เผยแพร่เมื่อ 24 ม.ค. 2015
- In this video we will cover: What is a MOSFET. Benefits of using a MOSFET switch vs mechanical switch. How to use MOSFET as a switch. Go over example using a MOSFET as a switch with Arduino. Here is a link to the Arduino code used in the video: forcetronic.blogspot.com/2015...
Don't know where to start man,. But I want to let you know,, this video, demo, explanation, is really helpful for me..
This is exactly what I needed instead of relay
,, just starting from scratch here man..
God bless you
Thanks man. I was struggling with a P-channel MOSFET and now I know why.
Perfect explanation, Thank you!
thank -you for the great explanation and visual aids well done!
This was your first video I've watched and I enjoyed it. Thanks from a new subscriber
thanks for the best explanation of n-channel vs p-channel I have seen so far
I'm getting back into electronics after about 30 years. Thanks for the video, it's helping me to remember. Now if I can only figure out how to use my PicKit I'll be good?. 👍
Thank you for the video on MOSFET switch control using Arduino.
Awesome! Best explanation I have found!
Thanks for this. Really helpful. Your an excellent tutor!
Really great video, thanks for sharing!
Thanks, clear and easy to understand, I learned something.
Great video! Helped me to better understand N and P MOSFET, Thanks!
Awesome video. This should be required for anyone EE students at the beginning of any courses dealing with transistors.
Thank you. It was precise and helpful.
Your video on using MOSFETs was very informative and comprehendable.i would like you to do a video on how to use MOSFETs in constructing a H-bridge.
Thank you.
7:38 that finally solved my confusion about P-channel and negative voltage value. thanks.
Excellent, very clearly explained.
superb explanation . . easily understood . . Thank you very much . .
Good job. Thank you for doing this.
thanks for explaining so clearly
Thank you Very much Sir for sharing this video about transistor
very good explanation, thank you!
Explained thoroughly well
excellent clear explanation.
Great Video, THANK YOU!!!!
very helpful video!! thanksss!!!!
excelent video, thanks.
Awesome , thank you sir
Hello from India... Great video.. Very useful and informative 👌
Amazing video!
FT, Very Good Videos. thank you.
great video thanks
This is a great video. thanks for posting.
8:15 I think you can use a pullup resistor on the P channel base so that it is normally off when there is no signal driving the base as both an "initial condition" during controller powerup and as a "fail safe" if something goes wrong. One disadvantage of the N channel over P is that it is a high side switch which means that the device being switched always has live power to one terminal even when it is off. So there are tradeoffs with each approach.
very informative, love watching your videos!
Very good explanation...thanks
smart india 0
Hi ;Thanks for the video
Helpful explanation. I wish there had been G/D/S labels on your diagrams to help clarify the connections. Using an IRF4905 p-channel MOSFET, and copying the code from the video, I found that a HIGH signal turned it on and a LOW signal turned it off -- the exact opposite of what it says in the video.
const int pMOS = 3; //create variable for gate of p-channel MOSFET IRF4905
void setup()
{
pinMode(pMOS, OUTPUT);
}
void loop()
{
digitalWrite(pMOS, HIGH); //Hmm, this turns it ON!
delay(1000);
digitalWrite(pMOS, LOW); //And this turns it OFF!
delay(1000);
}
At 7:18 for the P-Channel the 5V is supposed to be connected to the Source pin not the Drain pin. The Arduino wiring is correct.
Yep.. P-channel MOSFET is drawn backwards. I'm still learning, so I had to go look it up.
Awesome video... God bless ...!!
Hi
Thanks for the video. I just couldn't get this working on a higher load than a LED. I have a 5VDC load that draws 2A. Could you please leave me some tips?
Great! Thank you!!!
Great, been a long time away for me,
I had a guess at what they were but needed to be sure.
N - negative side.
P- positive side.
(Side being the load)
N no power
P powered.
Which is the switch off.
What I hadn't known was the reverse drain and source. But I guess the diode should have pointed that out.
It get complicated when you've zenners and you're running reverse for low volt application. Then S to D works.
But the gate then can be/have more important characteristics.
Thank you for the video, it is very clear
5:12 and following may not be accurate for the mosfet used
5v on the gate will not garantuee the low Rds - you would need a "logic level" mosfet for that
the datasheet for the buz11 notes in the electrical specifications: Id 15A and Vgs 10v for a typical Rds of 0.03ohm
so, if you use this mosfet you might not saturate the mosfet with Vgs 5v, and the Rds might be a lot higher than what you anticipate, meaning lots of heat generated in the mosfet, and less voltage for the load, as there will be a voltage drop across the mosfet
Rds depends on Vgs, Id, and the temperature of the mosfet, if i understand the datasheet correctly
I wish the datasheet showed a graph noting the relation of Vgs to Rds
breadboard time, i guess :)
note: a "logic level" mosfet has a Vgs(th) of 1-3v - most of the time it will be noted in the description of the datasheet it is logic level
@KiSwiSje, I just came across this video and was going to point out the same thing but saw you already did, so thank you for doing so. Some logic level mosfets have an L somewhere in the part number to denote it is logic level but it is not guaranteed to have an L or that having an L means it is logic level. Some examples of popular logic vs not-logic level ones are International Rectifier's IRLXXX vs IRFXXX series, or a Fairchild Semiconductor FQP30N06L vs FQP30N06.
i like it to use it for boost voltage up and make good pair with capacitors 😊
Very gud information sir plz upload without Arduino circuit only with discrete circuit of switching both type mosfet
Nice video. Is it safe to connect the battery positive to the gate with a wire without resistance?
Thanks !
Hello brother Ilike your video thank you
nice video is there anyway to use the mosfet with floting ground ?
Perfect!!!!
I have a hard time finding a p-channel TO-220 fets with on resistance specified at 5v.
I think the gate voltage that gives the rated on resistance is pretty important?
0:51 "They Will Live Longer Than YOU WILL" 😂😂
thanks alot
Is it possible to put mosfets in series in order to increase the source voltage? For example I have 5 mosfets rated at 450 volts. Can I put their sours and drains in series, so that I can increase the voltage up to for example 1200v?
Just an advice, add gate, source & drain symbols too at 7:22, beginners get confused with terminals all the time
can u tell me about what is aurdino ...is it a micro controller or a micro processor.. explain to me
hi ForceTronics,
Please help me with this I have to switch a peltier module using a attiny 85 microcontroller.where the controller works on 5v and the pelteir works on 12v 3amp current.
so my 1st question is can i be able to switch my peltier module using my attiny 85.
and 2nd if yes which mosfet would you like to prefer to connect for better result. And do i need to connect a heat sink with the mosfet.
Thanks you
I need to use three MOSFETs to switch high voltage DC. Three phase, up to 220 DCV. Which kind of MOSFET do you recomand?
I Like That Video
This one can I apply for 430V using microcontroller.application is 5HP moter,can you give nessary circuit
How about a video about fets and e-bike motor control?
For a better understanding when it comes on N type or P type I would have state that N-Type is normally open or NO and P-Type is normally closed or NC. Am I correct ?
As arduinos are a bit old, can these be used on an esp32 or 8266. These have 3.3v volt output. If so, can the go straight to the pin? Info on the internet is conflicting.
that's a lot of kit for a slow switch between the LEDs ? If I wanted say 2000 HZ at 35 amp 40V dc would I need this kind of set up ?
make a video on how to use mosfet as switch in place of relays in car wiring harness
Do you know how to connect two P-MOSFETs in parallel to give the same current, please?
Enjoyed many of your arduino videos but your BUZ11 is not recommended for 5v. Special logic level fets are indicated for 5v. Most power fets are designed for 10 volts drive. Also if higher currents are anticipated a series gate resistor is needed to lower the frequency capability of the fet. A fet is really a programmable device depending upon the series resistor value. Power fets make excellent series regulators but must have 10k or higher series gate resistance. A series gate resistor should always be used, if the fet oscillates it may fail from various reasons. I have made power oscillators up to 150mhz( before failures) using typical parasitic inductance values.
The threshold voltage of 2v to 4v is where conduction may start. " threshold" after 4v the resistance will decrease to the Resistance of 0.040 ohm at some level below 10v.
Ray King
Ray,
Any recommendations for a similar fet that has similar voltage / amperage maximums?
hi Ray, so following your thinking which is the right mosfet to use?
Besides the P-channel MOSFET being drawn backwards @7:01 , the only thing you might have added is how to attach an insulated heat sink (non-conductive heat pad and nylon screw/nut).
Thanks for your comment, Chris - I thought the p-ch MOSFET was upside-down - it should have the source connected to the positive rail.
Sir ek bt clear kar de mosfet or transiste ek he tara kam karte hain kya or kya ye sb resistans transister mosfet rectifire alag alag number k alag alag kam karte hain agar alag alag kam karte hain tu sub k bare me kese yad rakhe koi easy solution bata de plzzzz
thanks what does it mean if my LED doesn't stay on it stays on for a couple seconds but then fades away does this mean my mosfet is broken or damaged
I wish that I had paid more attention ! Before TH-cam was available.
What kind of P channel was used? I tried the IRF9540 but it doesn't work. With the IRF540 it's ok.
I want to switch 48 dc (i,e i am not applying any load, i just want to break the circuit when needed ) but I don't have 48v dc relay.
can I use a MOSFET if yes how
1000 likes -Great
I want to connect a supercap to a mosfet so that when the supercap is fully charged, the switch is on. Should i connect the drain to the supercap and source to the H-bridge? and how can actually turn on the switch or how can i make it understand that the supercap is fully charged. I am so confused
Can i use BUZ11 N Chanel to switch 36VDC , 5A LOAD??
Sir your video is very useful thanks
Sir Rc curcite of igbt paller how to calculated resistance capacitor velue please video sed
Very nice presentation. Exceptionally well done. Do you know anything about "latching" mosfet switches? I need to turn a PIR "on" with a "pulse", a logic high from my AtMega 328 bare bones chip before it goes into POWER_DOWN_MODE. I need the PIR to remain on, until it receives another "pulse" from the 328 chip to turn it "off". I have found many examples on line, however NONE have been as clear as your presentation on switches and I am hopeful you might be able to explain an "on" "off" latch circuit. Regards
Have you figure it out?
Thank you I made a error about the load BEFORE the drain with P chanel IRL530n I solve it now
Can a MOSFET be used as a load switch to transfer 3.3V from one circuit to another?
hello can u tell me other mosfets name with gate to source voltage less than 5 volts
what is the P channel MOSFET used here???
Hello sir kindly make a video on 4 mosfet how to control 4 mosfet which is use in converters
Thank you for this very helpful video. It would be helpful to know the type of p-channel mosfet you used. Also, and I know this is a much bigger ask, could you do a similar video on depletion mode mosfet (when used, gate to source voltages needed to turn than on/off, etc? - Thanks again!
Hi. I just bought lot of 20 pieces of irfz44n, i was searching for a logic one and got this one up, so i thought it was logic, but it dosn't state that anywhere, and ofcource i discovered that after the purchase...lool.
Never the less, its specs are vds 55v ID 49A and VDR 17,5 mohm. Its for to be used with an arduino and controling a solonoid valve (12v 4,7W), so its almost the same as the buzz11 , and i can use as intended as a switch with 5v and 0v?
Most likely. You need to look for its threshold voltage spec or Vth and ensure it is lower than 5v and higher than 0v which it probably is
Haha great vid!
So I've been doing a long running car restoration and have been having a thought. I just ordered an arduino to get into programming a little, really boost my electronics potential, and was thinking of how I could replace most of the relay panel and computers in the car. It's from 79, the computers and relay panel don't do much that's too complicated, but they are big, bulky, and easily add about 3" to the passenger side foot well plus all the heavy gauge wire running everywhere. Also I think it would be really cool to make new wiring harnesses and be able to take care of all my check engine lights and whatnot in a custom manner.
So are mosfets a viable alternative to relays for headlights, wipers, starters, etc...?
Could I just run power through a fuse bar and then directly to each component with a mosfet at the component, and a signal cable from a control unit? Sounds like more cable but with it I could have a power wiring harness and a signal harness run separately. Or I could just build a smaller unit to replace the massive relay board and other hardware.
Or are relays better in most of these applications and there's a reason car manufactures use them?
I have not worked in the automotive industry so I can't give you an exact answer on why they use relays versus MOSFET. My guess is relays are better for the rugged life of a vehicle since they are less susceptible to electrical noise and harsh environments. Also automotive is a highly regulated industry and they maybe required to have a literal air gap when an electrical connection is turned off (often referred to as galvanic isolation)
That does make sense. And how are MOSFETs susceptible to electrical noise; what should I look out for when using them in a design?
MOSFETs require less power to turn on then relays. If you have wiring connected to the MOSFET that is not shielded it can act like an antenna and pick RF noise. Also I believe vehicles are noisy electrical environments in general. For instance when the engine is started a huge spike of current is pulled from the battery which can induce noise onto the electrical system. There also may be other sources that I am not aware of.
So can i use the n channel with arduino and dc motor to give a signal HIGH from the arduino pin to make the motor run on the 5v
Yes, assuming you get an N Channel MOSFET that can handle the current of the motor and connect things up correctly.
Add a flyback diode !
Sunderwolf Impulse I would like to know if the Marshall amps that are of the Mosfet variety have a whole bunch of these mosfet gates or are there only a few ?I really like the sound of them and was wondering if they still use them and just don't play up that fact or was there a problem with their use?
You forgot to mention the capicity of the MOSFET and the resulting effects of these capacity. E.g. It is no good idea to connect an io pin of a mcu without a resistor to the gate of a n-channel FET. Also there should be an resistor between gate and ground allowing tha capacitor to discharge when FET is switched off.
Hi, thanks for the video. Can the GATE voltage be above 5v? (i have between 7 - 10v)
***** Can the GATE voltage be below the Source Voltage? my source voltage is 19V but it didnt work.
***** Thanks for the quick reply, i want to switch on/off a led strip whenever i turn on/off my pc monitor. The monitor uses about 8v for its backlight, so i conected it to the gate, and the led strip (12v) is conected via the monitors psu(19v) and a step down converter to the drain. Source is conected to Gnd. I have a buz11 mosfet. It didnt really work because the leds were very dimm. Maybe a RFP30N06LE mosfet would work? however i dont know if it can handle the 8v of the gate.
You have a problem on schematic. You are connecting wrong the PMOS with drain on VCC and source on GND. In that case the body diode will be forward bias all the time. The PMOS indeed is used on high side but with source on VCC and drain between load and GND.
+Adrian Carstea
I had to look at that twice, and I too was convinced he was wrong as the Body diode will conduct all the time.
+Adrian Carstea Yes that's wrong
for automotive application which one do you think would be better- pMOS or nMOS ?
Both are equal. The determining factor for P versus N is where in the particular circuit you are working with is the best place to put the switch. If it is between ground and the load then N is the best. If it is between the load and power source then P is the best.
Could you put a link to the specific blogpost that has the code? (maybe I just missed it) thanks!
Here is a link to the code. I will add to video description: forcetronic.blogspot.com/2015/01/how-to-use-mosfet-as-switch.html
Hi, is it necessary to have a pull-down resistor attached to the gate for N-mosfets? Some people say, the mosfet could misbehave without it.
+Anab Akanda Having a pull down resistor is a good idea if you want to ensure the MOSFET is in a known state when the MCU is powering up or is reset.
+ForceTronics Thank you. Makes sense.
Please help: I'm using a npn darlington tranzistor to switch on D.R.L. lights on the car . Been using the tranzistor as an amplifier and it is directly connected to the battery and switching on when there is power from the ECU.
The problem is that it has a voltage drop of aprox 2.2 volts witch is way too much for the DRL brighteness , it's dimming the lights with defeats the whole purpose of Daytime Running Lights. Please help
Bd901 is the tranzistor
Maybe you could use the transistor to activate a larger mosfet that has a lower voltage drop. Or use LED DLRs.
Kuri the wolf Thank you for your reply. Could you name one that works with 12-15V 2W and unde the hood car temperatures? Maybe 42C degrees
Any i buy on the internet seem to be rated for it.
Hello sir,
Can you help me for Dimming COB DC lamp with 28V 670mA?
1. TIP41C BJT [100V 6A 65W] it is getting to much hot.
2. IRF540 MOSFET[100V 30A 150W] it is not giving effective dimming
Other Option is to use TIP120C BJT[60V 5A], IRF520 MOSFET[100V 10A]
Which is best IC to use with 4N35 Optoisolator to dim DC with ARDUINO ?
can 24v 10 amp power control be provided with arduino with this method?
The answer is yes as long as you properly spec your design to handle the power level and heat dissapation needs of the design. There could be additional circuit design needs depending on your load. For instance if you are powering an electric motor there could be inductive fly back that needs to be addressed
Hi, can my Vdd be more than 5v, for example 30 V and my load be a battery? Here I am thinking of charging a battery using a solar panel, but controlling the process using a microcontroller.
+Elisha Mufambirwi Yes, it all depends on the MOSFETs ratings which you can access through the datasheet. Here is a link to the IRF540N which has a rating of 100V www.irf.com/product-info/datasheets/data/irf540n.pdf
I cant find any large mosfets where I live. I can only get scrap electronics and use what I find. I have several smaller mosfets, can I use them in parallel for more power? Like resisters, if used together in parallel, they split power flow between them and conduct more power and lower the resistance, can mosfets work the same?
+Randy Travis In theory yes, you can put them in parallel to divide up the current flow. From a practical standpoint there are a couple challenges or pitfalls with this approach. First they may not all have the same on resistance so one of them may get more current than the rest. Second if they don't all turn on at the exact same time then one will get the full current for a short period of time.
That might be a problem. I plan on making a stun gun with a voltage multiplier and a flyback transformer, its going to be some fast killer voltage. I think I just might go out and just get a beefy relay, that might be a better idea, any ideas?