Simple easy transistor delay circuit - Explained tutorial | How it works

[@borsi99]

Thank you very much for your excellent explanation of this transistor circuit! Never before I‘ve seen the working of multiple transistors that way. Hope you go on with circuits like this! Greetings, Bo 🇨🇭

[@GlevoTec]

Thank you! I appreciate comments like yours. If you have any circuits you would like to see, feel free to suggest. Greetings

[@reverseengineering1931]

The best explanation I found ever to learn electronics though I'm a mechanical engineer still understood each word that you spoke...love from india🇮🇳🇮🇳🇮🇳keep up good work

[@GlevoTec]

Thanks!

[@mattrothe149]

This is good I like it. Some people will need high side switching with the second transistor being being a PNP. The relay also high side, might be 20 or more feet away so best to send 12V at a 1/2A. Extra credit for not using a FET.

[@danmoscaliuc1881]

Your videos are so underrated. You are an amazing teacher.

[@GlevoTec]

Thank you! I really appreciate that. It's motivation for me to keep going. I'm glad you liked my video!

[@shvideo1]

Awesome circuit, masterfully explained in detail. Thank you for taking the time.

[@GlevoTec]

Thank you. I appreciate the feedback. I'm happy you liked it

[@shvideo1]

@@GlevoTec I wish you would do more on topics like this. You are great at it. Simple practical (useful) transistor circuits are fun and a great way to learn as you have already mentioned in your video. Thanks again.

[@GlevoTec]

@@shvideo1 Thanks, I'll keep that in mind. Only I've noticed there's not so much interest anymore for these kind of videos. Although I like doing this. If you have any suggestions, please let me know!

[@shvideo1]

@@GlevoTec You are right, but at the same time there so many electronic enthusiasts. Understanding this stuff is pretty important, and as you know it’s really fun to put together simple practical circuits like this and to know how they work. Just looking at the feedback on this video, you can see that you have it down. Thank you again.

[@GlevoTec]

@@shvideo1 Thank you, I appreciate your thoughts, really. Comments like these is what I need to grow the channel. I wish I had more people taking time to leave me a useful comment. You know, I have some ideas, I might do something with it soon. Keep an eye on the channel. And thank you again!

[@isurusamarathunga3835]

Dude I been watching your “how things work” series and they are so damn good! Love this, led flasher and the one about cassette tapes. Love how you explain everything from the beginning and your mindset on how basic electronics are indeed magic and sadly everyone using microcontrollers for every little thing these days. I really really hope you will keep making those videos.

[@JAVIMETALL]

Thanks! I'm starting to learn some basic electronics by myself and this explanition is solid and clear

[@GlevoTec]

Thank you! I'm glad it could help you

[@zetaconvex1987]

Nice tutorial. I'd like to see more simple circuits like this.

[@gibingeorge4266]

Simple and clear explanation of the topic .. Thank you !!

[@GlevoTec]

Thanks!

[@matthewberry201]

Great video thanks, would you use this instead of a 555 monostable circuit, if so why?

[@GlevoTec]

For simple circuits like a blinker yes. But for higher frequencies a 555 is a better choice.

[@kobie1585]

Wow , i just liked your video and subscribed to your channel.......Good one Boss👍👍👍

[@Saveindian]

I have subscribed you from India.

[@GlevoTec]

Thank you!

[@Studywithstudent97]

Best video ever🤓! Thank you so much!!!

[@eyalyehuda5420]

Well, I think I’v got my self a teacher:), I am a soft engineer for more than 20 years now, I’m a Linux kernel developer. Electronic Is my new hobby, and I am talking about analog circuits only. I wish to connect with you for a few basic questions regarding frequency of flip flop . I’d appreciate it if you can tell me how we can establish any connection for Q&A.

[@sulingli5517]

I like you videos. Thank you Sir

[@darshpandya7952]

What Resistor Model u have used for Ex MINRES or what ?

[@kd5txo]

This is a perfect circuit to make an automatic shower flow timer.... use a thermostatic mixer to control water temperature along with a normally closed servo valve.....then just tap a switch for a regulated shower lasting a certain duration...... tap as many times as you want to prolong the flow of water. No more twisting valves!! This could conserve both energy and water by using the "Navy Shower" method... perfect for off-grid solar powered households.

[@GlevoTec]

That's a great project. This is a very versatile simple circuit indeed. It can be used in many solutions and be used as a building block to build more complex circuits.

[@kd5txo]

@@GlevoTec It appears the idea has already commercialized by a firm headquartered in Bath, UK they sell the basic fixture for 375 UKP ....just a knob (adjust temperature) and a pushbutton to start showering.

[@mandingoteckdailey5235]

Can you please do a video of a transistor controlled voltage regulator with a current limiting functionality.? That would be a great video. You can even break it into parts.

[@jonathanaird5840]

Hi, Great video.... thanks. I am trying to make a 24 hour delay circuit which will turn off a load after this time. However, if it is tripped during this 24 hour period, it starts counting from zero again

[@prakashsharma6186]

Kindly explain how the voltage is inverted at collectors of transistors.l I love your vidios and subscribe your channel. Love from India.

[@techtinkerin]

Very helpful thank👍😎

[@Irshu]

How did u come up with the values for the resistors? What equations did you use? Thanks for the video.

[@GlevoTec]

Good question. I took some random values here. But you can calculate the time constant of a resistor-capacitor circuit with t= R*C. This is the charge/discharge rate where it charges or discharges 63%. Full charge or discharge takes 5t, or 5*R*C. Look up RC time constant for more detailed explanation. Hope this helps!

[@Irshu]

@@GlevoTec thank you.

[@fuljahanbegam6793]

Very nice

[@byGDur]

Can you show the same but using a hall effect sensor as the switch. Eg when a magnet goes by the hall effect sensor, the delay circuit starts. thanks

[@GlevoTec]

Very simple. You don't need a hall effect sensor. Just a simple reed-switch in place of the switch and it will work perfectly.

[@byGDur]

@@GlevoTec thank you for the reply. I think that is a good idea. I would like to use the circuit for my bicycle. The magnet would be attached to the wheel and the sensor to the frame. I think the hall effect sensor could be more error robust. Even a hint or link in the right direction would be greatly appreciated, thank you

[@mandingoteckdailey5235]

Great explanation. The only thing missing is you didn't explain the the time constant related to the circuit and how that controls the delay. It would have been perfect if you did that and explained the math involved.

[@GlevoTec]

Thank you. I left that out for simplicity. But I'll keep it in mind for future videos

[@richeobrador9611]

Thank you very much

[@arifahmed1121]

how much power this Circuit consume when It's off? i mean when capacitor discharged, LED turn off.. but this circuit connected to the Battery, now It's keep draw current or totally off? 0 power consumption?

[@nainghtooaung500]

Very thanks

[@ssaacchhiinn8138]

Is the transistor used FET (VCCS)? Because BJTs are CCCS.

[@GlevoTec]

No, just ordinary bipolar junction transistors.

[@davyisbert5122]

Hello Could you please do the same for delay on Br Davy

[@jendak7921]

I need something like this but without button. When powered it turn on relay and after few second turn off. I tried three circuit i found for this but no one work properly for example too slow turning relay on after powered I need it immedietely. Also operating voltage is 12V when main power supply and backup is 6 rechargeable AAA so I use 5V relay and zener diode so relay work on both voltage and delay circuit also must work when on battery.

[@lawalmohammed83]

Can the circuit be used to turn on an alarm circuit for some time?

[@GlevoTec]

Sure, why not

[@robc4191]

So could the two transistor circuit be used as an on-delay?

[@GlevoTec]

No, but you can modify the RC circuit to make an on-delay. If you simply place another resistor between the button and capacitor, you'll have added an on-delay. Hope that helps!

[@Blue.star1]

What is the quiescent current

[@alchemy1]

If we just observe we can see how simple the real principles are and that is about all of it. The complexities are not in the actual principle but in how various things having different names/labels and having different physical shape/appearance are placed with respect to others that cause and make different things happen. What is information/memory/data? That is in the computer lingo system. Look it is energy. Correct. In the old days this energy was held in what we understand to be magnetic field. Then it became cumbersome and bulky. They decided it was much easier and more efficient to use electric field. Energy held in electric field. What is then memory cell. Simple, it is a capacitor. What is a capacitor. It is a mechanism that keeps the opposite charges apart. This holding of separation of charges cause an electric field between them. What is a timer, the core of it. It is again a capacitor. Small capacitor charge and discharge rapidly and larger capacitor ..... you got the idea. Sensors, transducers, signals, inductors, hall effect... blah blah blah blah.... if you look very closely, they are all the same stuff doing the same thing but having certain look and being placed in a certain place in certain way, perform different roles and therefore given different names. Variable resistor, adjustable resistor, potentiometer. Look, a diode, a transistor and a capacitor... do you see that a diode is also a capacitor and so is a transistor. Wait wait. Everything has capacitance. Your light switch in your bedroom is also a capacitor. Trust me it has capacitance. and so does all the wires.

[@GlevoTec]

Well said. Indeed. All the electronics in the world, no matter how complex still work on the same basic principles. Everything is basically a unique puzzle of different combinations of principles and optimized for the unique purpose. Look close enough and everything is very simple and similar. It's indeed the labeling and methods of combining things into sub-parts that make it complicated and require specific knowledge about it

[@alchemy1]

@@GlevoTec After all these years of struggle and all the grunt I have reached and have concluded it all with this: " You do not know anymore than your ability to explain something to another in such a way that they would truly and fully understand it". If you can't do it then you yourself don't really understand it either. Now, anyone will have to think twice to brag about their professorships and their credentials. When they teach... how do computers turns 0s and 1s into text, audio and video. I stand opposed. I say because they don't.

[@thuydang3668]

I still don't know how do they turn on and turn off automactically when switch closing. Could you explain for me .thank you.

[@hkcccc2889]

[@RC-Heli835]

This is awesome man! Do you know of a circuit that will continuously flash an LED twice rapidly, pause and repeat? **__**__**__**__**__ Like a jet airliner!

[@AztecWarrior69_69]

You don't need so many transistors, all you need is a zener diode.

[@magnuswootton6181]

learn how to do a delay just like this, helps immensly if you want to design your own stuff for real!!!

[@LJacyHenry]

I love actual electronics. Not arduino non-sense. Everything is just arduino and go nowadays. It's programming not electronics. I build all my amplifiers with discrete BJTs and JFETs ocasionally an op-amp. I hate 555s and other chips I can never figure out how to use. It is much easier for me to just pull out my trusty MPSa42s and do what ever I want.

[@GlevoTec]

Thanks for the comment. Real electronics is learned by building with discrete components indeed. But I do admit that an opamp or 555-timer are incredibly useful and I like to use them for certain projects. And that's alright, as long as you take the effort to understand what is happening inside the IC, in my opinion. I have a handful of basic IC's in my stock that come in handy sometimes.

[@shvideo1]

This circuit did not work for me when I built it. For the middle transistor, having a base transistor of 22K and a collector of the same resistance value does not seems to make sense to put that transistor in saturation! The base resistance is typically 10 times or more smaller than the collector resistance!!

[@GlevoTec]

Strange. Try to build it with the same component values as here, and use BC547 NPN transistors. 22k as a base resistor is plenty of current to saturate the transistor, since the BC547 has an Hfe of at least 180.

[@shvideo1]

@@GlevoTec will do. I forgot to mention that I did use 5 VDC as power supply. A lot of people demo with 12 v, but that is not a very convenient portable value. I also tried to energize a 5v coil relay, but it wouldn’t energize. Thank you for the reply.

[@GlevoTec]

@@shvideo1 That will be the problem. This circuit works best at higher voltages. Although, with tweaking of the component values, you should be able to get it to work at 5V as well

[@shvideo1]

@@GlevoTec Yes, I think so too. I started from scratch building each transistor stage using 5 v and an led at the output. I got 2 stages to work. Now working on the 3rd stage. I think you are great at explaining these circuits. I wish you would do more small practical transistor circuits. Thank you for all your input and your channel.

[@GlevoTec]

@@shvideo1Thank you. I'm working on a new transistor circuit video actually. Also, if you're driving a relay with your circuit, make sure that the last transistor can handle the drive current of the coil. The BC547 that I used here can only handle max 100mA. So you might have to change to a more powerful transistor. Good luck!