MOSFET delay circuit

Get professional PCBs for low prices from www.pcbway.com -~-
In this video we use an N channel enchancement mode MOSFET as a swicth and then we create a tank circuit to control the timing of the switch. When we put them together we get a circuit that switches on when you press a button and stays on for a length of time determined by the tank.
(5PCS) IRFZ34NPBF MOSFET: amzn.to/2xOKsES
6x6x6mm Momentary Push Button Switch 10 pack: amzn.to/2z9evZI
Electrolytic Capacitors Assorted: amzn.to/2A8G6tU
1/4 watt resistors kit: amzn.to/2xOZBWU
5mm LED Assortment: amzn.to/2xP1SRW
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[@dhudzina]

These have become my favorite videos of yours. I'm self taught and it feels like there's a lot of places to get reviews, teardowns and arduino stuff (not to say your's aren't good and informative) but not a lot on the simple circuitry design. I'd like to see more of this.

[@learnelectronics]

+dhudzina Thanks. Check out my basic electricity and electronics playlist. There are 56 videos in it all about circuits.

[@shvideo1]

Great simple practical circuit. Love your explanation and demo as well. Great job. Thank you.

[@georgechambers3197]

I just love seeing these simple circuits that take a few components. These days we tend to think of specialized IC's and such for things like this! Thanks for the video.

[@learnelectronics]

+George Chambers anytime my friend

[@carldavis8228]

I agree. Good down and dirties, just like his logic circuits. Understanding the building blocks, that's what counts. Since I am self taught, learned the fancy stuff, but never did get the reasoning behind a circuit at its lowest level. I hope he keeps doing circuits like this at least 30% of the time.

[@georgechambers3197]

Hey, that's what I think learnelectronics is all about! Paul is a great teacher at least online? He's got the best teaching technic since Forest Mims III at least in my opinion.

[@igrewold]

I agree with your, sometimes something amazing can be done with just transistors. Also them generic ICs are very useful like 741, 555 timer and them AM radio chip (MK484, ZN414, TA7642) kinda look like a transistor...etc. en.wikipedia.org/wiki/MK484 BTW you can get an assortment of chips for a cheap price to tamper with www.futurlec.com/ValuePacks.shtml

[@georgechambers3197]

Good link! Thanks.

[@kobie1585]

Great Video Boss👍👍👍, I've just subscribed to your channel and liked your video.... Greetings from Ghana 🇬🇭, West Africa

[@danielroibert5631]

Hello, thank you for this nice video. This is good for low current, but, for important currents and long durations, the transistor is going to warm because it stays relatively for a long time in intermediate regime. It is then better to add a Schmitt trigger somewhere in this circuit before the power transistor.

[@samk2630]

Love the intro on this vid

[@stevecahill9106]

Good demo. If you hold down the button does the LED stay on? When it is released that it starts the timing ?

[@melplishka5978]

Nice one Paul.

[@christiannielsen3863]

thanks for the video. like in some other videos I am missing an explanation on how the current flows in the circuit. for example I dont get how the current flows from the timing resistors and to the capacitors and how it discharge slowly etc.

[@peterjol]

this was just what I wanted ...works a treat thanks.

[@milesmoore5422]

What can you do with it ? Where would it be good to use ? What about timing adjustment by turning a screw or nob ?

[@naderhumood1199]

Big thanks, aptly great project while staying home far awy of Corona virus..... from kingdom of Bahrain...... Peace ✌️🇧🇭

[@steve6375]

So you can use any MOSFET? It doesn't matter what the Gate Threshold Voltage is? I always thought that for use with logic, you need a MOSFET which has a Gate Threshold Voltage of under 5V, otherwise it won't turn on. The IRFZ34NPBF which you used has a Vgs(th) of 2-4V and so will work with low voltages. Many MOSFETs have much higher threshold voltages and so won't work in your circuit AFAIK.

[@hadibq]

👍 great classic masterpiece circuit well explained sir!

[@magnuswootton6181]

it would be cool to see a switch on delay based oscillator. awesome if u could do it!!

[@tindicio44]

I did this circuit but does not work. I guess the 12vdc power supply has a huge ripple and an ac componente goes across the intrinsic gate-source capacitance and recharges de electrlitic capacitor and this way the mosfet never turns off . Is it possible??

[@blackpinkhitmewiththatddud4237]

Sir how about for delay on timer? Can you please give a schematic diagram for it. Thanks

[@emanuelsilvapt]

Do you think it could be used to stretch a duty cycle from a pwm?

[@JREMC2]

If I have only a negative input, like in a car, how should I manage that, for the same result?

[@Ex-fk4nr]

is changing the source vorltage from 9 to 12 v gonna change the timing aswell

[@autoworldgentech3304]

Can this work on 12v for a cob led tks Nice video btw.

[@harrymatharoo1969]

Sir, it can b used for power factor correction on welding sets...great video...

[@michaelpadovani9566]

Here is another example of a simple circuit that has wide reaching application possibilities. Could tie a pot instead of individual resistors to control delay, although it would need to be of the large value type.

[@igrewold]

Great idea, since he said 1~100Mohm then maybe a 100Mohm pot will do.

[@tomlomax9909]

5:04 Interesting to see the decay of the load current at higher R1 values

[@michaelanderson7160]

so if i needed to add an ascending volume control to an alarm speaker so not to scare a person awake rather to get louder and louder

[@raytru3191]

if i got it right the highter the resistor the longer the delay great voi always find you vid most interesting

[@learnelectronics]

+ray tru thanks

[@jamest.5001]

so can a l.e.d be used in the gate of a FET. along with a resistor. .To drop the gate voltage? or would that harm the MOSFET? for like a 24v system. and would the popular IRFZ44N be good for an 15-18 amp inductive load. at 22-29v. in a pulsed cycle maybe 10 kHz. to guessing maybe 20kHz. I'm sorry I have a lot to learn. I can't afford to buy and burn components! I know at my level. things will happen. but I try to salvage components for just playing around. but I need to build 6 regulators and will be buying multiple components. and can't be burning them. thanks for your help.

[@snnwstt]

A little (a lot) late, but here is how you can make a fast check. Use a datasheet such as at pdf.datasheetcatalog.com/datasheet/irf/irfz44n.pdf. Look for the SOA. For the given reference, that is figure 8. You should be able to see that for 30V, with a single pulse of 1milli second, you are good for about 9A. Furthermore, as long as you are below the horizontal upper limit, you can add a thermal radiator if you need higher current. Note that the figure assumes that your transistor is in air at 25C (ie, not inside a poorly ventilated enclosure where the temperature could be much higher).

[@nadachikh1829]

I wanna know how we can control the delay time without changing the resistance or the capacitor every time we wanna have a different timing?

[@miked7923]

you cant, those 2 components are the main timing items. Maybe with a potentiometer you can change the timing more easily.

[@nadachikh1829]

@@miked7923 thanks a lot , tha was so helpfull

[@quoit99training83]

Another great electronics lecture! Do u have any plans on making tutorials using raspberry pi / automation? Thanks.

[@learnelectronics]

+quoit99 training I have a number of Raspberry pi videos.

[@mahmoodali7082]

A large diagram helps in improved learning

[@MicrosiMe]

Nice

[@diamony123]

This lends its have to a rising edge detection

[@sayantanmaiti2513]

What if I place a power BJT in place of that MOSFET???

[@learnelectronics]

+Sayantan Maiti really doesn't matter, it's just a switch

[@gartmorn]

Does it not need a current limiting resistor to the gate? I assume because the button is held in very briefly it doesn't matter or am I getting it all wrong? I'm not an expert on electronics as you've no doubt gathered!

[@learnelectronics]

+gartmorn No resistor. MOSFETS are voltage driven. They sink no current.

[@gartmorn]

Of course. Need to lay off the old scotch whisky! Thinking bjt! Good wee timer btw!

[@danielroibert5631]

See the datasheet of the mosfet. most mosfet accept until 20V for gate- source voltage. the IRF234 is in this général specifications.

[@carldavis8228]

BTW, I did not see an add on this one.

[@learnelectronics]

+Carl Davis Yeah, KZbin is putting me out of business.

[@hkcccc2889]

[@jdragon8184]

damn i wanna like the video but no of likes is 333 a perfect palindrome ,smhh

[@jdragon8184]

adding the 70 th cmnt will also be vv difficult but love my mosfet timer

[@James_Bowie]

kilohm and megohm.