Adjustable strobe with 555 timer and 1W LED

[@nigeljohnson9820]

If you want to use an LED as a stroboscope, it is important to generate very narrow on pulses. I have found the simplest way to do this is to use one of my favourite ICs, the quad nAND Schmitt. With this, one gate is configured as an RC oscillator, two are connected as a monostable and the last provides logic inversion. A single mult-turn pot allows the oscillator to be frequency adjustable, its output triggers the monostable which gives a fixed narrow pulse width that can be adjusted with a preset pot or switched resistors, but more of that later. The output of the monostable can be inverted to drive the N channel power MOSFET which powers the LED. As the LED is driven with a high current, beyond its DC power rating, the LED can be protected from a fault condition that leaves it in the on state by AC coupling the pulse signal into its gate. To facilitate this, the gate is coupled to the driver circuit with a low value capacitor and a pull down resistor and reverse biased clamp diode are fitted in parallel to ground. To ensure the oscillator frequency and pulse width are not adversely affected by the high current pulses taken from the supply, in my case a 9 volt battery, it is necessary to fit a large reservoir capacitor across the supply rails to the LED and MOSFET. It is also necessary to regulate the supply of the quad Schmitt with a 78L05 linear regulator circuit. A low value resistor is also placed in series with the LED to limit the maximum current it can take from the battery. A suitable working range for the pulse width is between 10us and 100us. The oscillator frequency can be set from a few Hertz to a few kilohertz. I have run tests where the LED has been pulsed up to one megahertz, as confirmed by photo diode connected to an oscilloscope. At such a high flash rate the pulse width must be very narrow to avoid overheating the LED. In practice, a maximum flash rate of two or three kilohertz is suitable for for most stroboscopic applications, particularly as fast rotating machines can be viewed at harmonics of the flash rate. At very low flash rates the average light output is noticeable lower and increasing the pulse width above 10us improves the brightness. ( 60us to 100us is optimum). I have used this circuit to examine the spinning blades on computer fans and freeze the motion of high speed drills as they cut through metal. P.S. there are a couple of circuit tricks that can improve the isolation the linear regulator provides from the led current pulses. If a power diode is placed in the input to the regulator, followed by a reservoir capacitor to ground (zero volt rail), the very short pulses reverse bias the diode, stopping the reduction in the supply voltage, due to the high current demand, from pulling down the rail supplying the quad Schmitt circuit. In the monostable and MOSFET driver, where a capacitive load is being driven with a clamp diode fitted, it is important to protect the Schmitt gate output with a series resistor, with a 5 volt supply to the Schmitt IC, a 270 ohm resistor provides a good margin of protection to limit the gates output current.

[@learnelectronics]

Wow! Thanks for that. I hope folks read it Nd apply 8t to their designs.

[@neilgroves3592]

Do you have a schematic for your circuit?.... sounds very interesting

[@nigeljohnson9820]

@@neilgroves3592 as I did not generate a PCB, the circuits it is not in my computer archive, however I could draw up a copy of the circuit diagram, but I am not sure how I can post it here. It is a relatively simple circuit, using a few tricks to make it work with low-cost components. None of the components are particularly critical in value. As far as I remember it uses a CD74HC132 Schmitt trigger and a high power blue Cree LED, as I had a few free samples. I have been meaning to build it on PCB, as I have a hand torch which would be an ideal case for a stroboscope. As the pulse mark space ratio is so small, it runs perfectly well from a PP3 size battery. In a finished design I might use a rechargable NiMH of a slightly larger capacity. The reason the project has not been finished is because I was having a problem finding a heat sink to back the LED that is compatible with the parabolic reflector in the torch. My prototype was completed on vero board and was sufficient to perform the tests on the computer fans and their speed controller. I was also playing with the idea of adding a five digit LED frequency counter read out of the flash rate, rather than use the bench counter. There are all sorts of enhancements that can be made, but the commercial versions are not that expensive and you quickly wonder if it is worth buying rather than building when you start adding more complex features. The basic circuit cost practical nothing to build and provides a very acceptable stroboscope function, all be it rather basic compared to the much more relatively expensive commercial offerings. PS I have found a copy of the original circuit in my lab book. While a picture (circuit diagram) speaks a thousand words, the circuit is so simple I could describe it.

[@richard1113]

Love your videos because you are real. Mistakes are not taken out. "I don't know why this is happening" not taken out. You are a true hobbyist, and I respect you immensely. Keep doing what you do!

[@learnelectronics]

Thank you!

[@jimmyneutron8702]

Fr man, it’s those moments that make me love this channel and its tutorials!

[@TheTubejunky]

The 555 timer ic is one of my favs. I've used it for a strobe light like 5 years ago. It's so awesome that this ic still gets recognized and appreciated. Thank you for your great upload sir.

[@sachinkokate5060]

Send circuit diagram

[@TheTubejunky]

@@sachinkokate5060 circuits-diy.com/led-strobe-light-circuit-using-555-timer/

[@TheTubejunky]

I used a 5v relay with a hand held flashlight as the output leds. I put a diode on pin 3 as to stop inductive kickback from the relay coil.

[@CogitoBcn]

I've used the 555 IC, at least, since 30 years ago... 😁 so it's used an valued for more time that you think.

[@dalenassar9152]

My two cents: a variable speed spinning motor with a white dot on a dark shaft would really help show the "stroboscopic effect". When the LED flashes at such a high rate that you can no longer "see" the flash, that is due to "PERSISTENCE OF VISION". GREAT VIDEO!!! I am going to build one in a box...

[@HelmutTschemernjak]

Great training video like always. Why not to put up a schematic as well, maybe at the end. Regards from Germany.

[@alsnow3582]

Agree. Even if it's as simple as this one. Hand drawn on a piece of paper would be fine.

[@sonnylou8087]

Ok thank you I will get it on the bench and start at the begining and work my way around with the fluke and we’ll see what I come up with, thank you for your response I appreciate it and I’ll let you know what I find.👍

[@jayherde0]

@learnelectronics - Just a little breadboard tip. When you use components with flat leads, like ICs, MOSFETs, Pots or such, twist the leads 90 degrees. They will go in better, stay put better and cause a lot less wear and tear on the breadboard. You can test this by turning the component 90 degrees. Of course, you can't do that and have your circuit work, so just twist the leads. ;-)

[@dalenassar9152]

I have been doing this since I saw the inside of a breadboard...good to hear this from someone else. I have probably posted 50 comments explaining this...but have not ONCE seen anyone do it. The regular way REALLY damages the breadboard! Another rare thing that took me many HOURS to track down...A jumper wire was inserted in a breadboard, but not quite enough bare wire was exposed, and the insulation slipped in, and there was no contact. I believe one can learn something new like this, or a better technique do a particular thing, with each project. BEST THING I LEARNED: clean up as you go...

[@KobraVR]

Great job mate I finally got my stupid circuit to work after trying 20+ other tutorials 😄

[@Friendroid]

Thanks for sharing, I'm going to try to put this together tomorrow. Coincidentally I'm familiar with CHF, as my dog had it. Fluid would accumulate in her lungs so she had to take lasix for the rest of her life.

[@sjafarsayyedi8869]

Dear Sir, I thank you for your efforts. But I think if you show us a clear schematics diagram, it would be easier to understand things. Thanks.

[@paul-c7541]

You kinda see the flash rate as a reflection on the scope screen Paul, looks pretty good to me

[@MrFrazierNation]

I just got on eBay to order my 555 timers with sockets and some 3W COB LEDs. It's 4 am in the morning 🤣😒🤣

[@alsnow3582]

This gives me some new ideas! Thanks Paul. By the way, I like the unscripted method.

[@learnelectronics]

Thanks

[@TheJatkumo]

Super informative and useful. No need for schematics as the arrangements are clearly visible and explained.

[@danjose4072]

Excuse me sir can I get a circuit diagram of this

[@pulesjet]

I used a few of those running 365nm UV to mod a flash light for mineral hunting and inspecting for scorpions here in the land of Disenchantment. NM. One 18650 cell can last a hour or so easy.

[@pulesjet]

The Camera Framing does that. Looking at my Wind Turbine it looks like it's only doing like 5 RPM when it's actually chooching along a some 700.

[@certified-forklifter]

haha, cool

[@MalagasOnFire]

That is very neat to put inside a pumpkin and big wires to potentiometer . Hummm triggered by IR barrier :P

[@christiannielsen3863]

I also love the small simple projects. Could you perhaps do a tiny project on how to simply make a servo motor turn 90 degrees clockwise and anti clockwise by pushing two different buttons for example.

[@learnelectronics]

Sure

[@Hooch737]

Sir, you taught me something today! Like I have a lot to learn 😝 Thank you

[@matthewberry201]

Really interesting, had to think how that feed back was effecting the frequency. I think it is basically charging and discharging the capacitor quicker?

[@jjab99]

Excellent way to have great fun at a really low price!! Many Thanks.

[@geirendre]

Of course you get a thumbs up for posting videos like this. Just put a resistor here, a pot here,hook up the drain there... And it blinks. That's great fun, and educational too. BTW, hope you are doing ok. Take care.

[@learnelectronics]

I am thank you!

[@blanana_m]

Do you have the schemetic?

[@Electronzap]

Nice video! My camera does picks up fast flashes the same way. Reflecting off something seems to help for a little bit. I usually make sure to have the right component values ready for the max flash speed that the camera will pick up nicely no matter how prepared I am to make an impromptu video otherwise. Hopefully I'll stumble on a setting that does better job picking up flashes some day.

[@pulesjet]

Most chity phone camera work good for checking IR transmitters. Mine can even show IR Laser beam.

[@Electronzap]

@@pulesjet Nice :)

[@tensor131]

how is the V & A regulated for the LED? 3v, 350mA .. no resistor .. I am confused on this point?

[@richard1113]

BTW.. I love your outtro. It reminds me of something but I can't quite place it.

[@murrrr8288]

Your videos are great, I learn a lot! I think I understood finally how mosfets work with this video

[@garrysingh4020]

Thanks, you're a good tutor. I am self learning electronics/electrical trying to find some used textbooks can't afford it. any good idea on where to find will be appreciated.

[@heed7496]

Can you make a 555 timer circuit without using the microchip.? Just all discreet components?

[@jeffk204]

Thanks, just the kind of video I was looking for in order to setup a flashing LED to go into a pumpkin! I just wired it up and it works.

[@moodberry]

How do you think I could make this SUPER bright? I want a strobe that can be seen in bright sunlight. Thanks.

[@piyushpriyadarshandas5630]

In 6:53 what potentiometer rating you used???????? And the capacitor

[@tpaul522]

I’ve purchased 7 colored 1watt led lights from the net for very cheap . They arrived mount in the light fixture with just stripped blue and black wire hanging off ,no switch no nothing, so how do I light and some how control these lights???

[@willyrivero470]

"Arduino feels like cheating" I so much agree with you. In my opinion working with arduino is no fun at all. It's the same as buying an already made circuit and just by adding a few more components to make something work is kind of cheating to say you made it. The fun of electronics is to build from the bones out. Your brain really starts working. I know many people won't agree with me but I always thought that.

[@neilgroves3592]

The advent of microprocessors in my opinion has ruined hobby electronics for me.

[@willyrivero470]

@David Wingood You're right. But even going that farther back it actually feels kind of fun. At least once in a while.

[@mamediarralo4283]

What assembly do you use to drive 7 sst uv leds in series with the maximum current in a les of 1.5A and 3.63 v

[@jlucasound]

Thanks for this! My favorite IC also and I am just learning how to implement it!

[@jonathanj-g-yyelle6144]

Real good job in explaining this! 👍

[@patrickmckowen1154]

Would this also work for a rave?

[@godislove3709]

Good job man

[@sonnylou8087]

I have a question, I was wondering what way is the best way to clean out heavy dust from the inside of my realistic SA-1000 solid state amplifier so that I can preform voltage checks?.

[@milesmoore5422]

Are you using oscilloscope software ? Can you show the wiring schematic ?

[@bigjobs5000]

Excellent work Sir. Your vids are a great source of learning - Thankyou!

[@bblod4896]

Okay, that's bright!

[@mrhejbump9351]

Thanks for this pedagogic video. Interesting stuff. A question: How would you set up components on your breadboard for being able to adjust frequency AS WELL AS adjusting duty cycle?

[@shorb2289]

changing the resistance changes the duty cycle/the rate at which the capacitor is charged/discharged. The frequency however is decided by the rating of the capacitor itself.

[@williammiller7543]

Another Great video. I just had a problem trying to use an ESP32 (Pin limit of 12mA) to a buzzer (3.3vdc BUT 30mA). The volts needed was the same But I needed more current capability. I have used a MOSFET in the past to drive a SSR, it also drew too much current (20mA) but also needed higher driving voltage ( at least 5vdc) than I had available in the ESP8266. I used the same MOSFET for this current (no pun intended) problem but there must be better or other alternatives for these low voltage/amperage devices. Help if possible.

[@deadalus888]

Hi Bro. How can I use this circuit to control a pump or motor??

[@bobhcr2872]

Can i connect it with multiple led

[@daveoswald5375]

Could i run the 555 and the mosfet on 12 volts , to power a 12 volt relay ( i want to fun a 120 volt light bulb) without needing any current limiting resistors ( no leds in circuit)? Also if i feed 12 volts into a 555, could the 555 feed its out put into a cd 4017 decade counter. just want to run everthing on 12 volts.

[@sho-nuff8256]

Pins 4 and 8 not connected in this circuit?

[@joaquinmedina7734]

I love your honesty, nice video, new subscriber here

[@PrincePloppy]

Your channel is awesome, im learning ...

[@mikeoliver3254]

Fun strobe circuit, definitely a classic. Great video Paul, m thinking about doing some motion sensitive stuff for Halloween this year.

[@dalenassar9152]

THANKS, I am looking for a good 555 circuit to flash an LED from about 30Hz to 150HZ. I do NOT want to see any flicker, which means the LED must flash faster than your "PERSISTANCE IF VISION" range. In other words, the after-image of each consecutive flash does dot give enough time for the image to "fade" before the next flash From your video, that looks like about 30Hz min. I never looked it up.

[@learnelectronics]

30 hertz is the accepted frame rate

[@clintonhunter7410]

Love these neat little projects, is there a way to have the strobe light turn on after a set amount of time like 5 or 10 minutes and have a reset button?

[@learnelectronics]

You could do that with another 555

[@MCsCreations]

Pretty nice circuit, dude! Thanks! 😃

[@1chrisandrew1]

Enjoyed that, many thanks. Have subscribed 👍

[@bastienguilbaud5768]

Is 260 hz the maximum frequency or can it go higher ?

[@Custom3dPrinting4U]

I wish you were my uncle lol I do cosplay and have to do research for months and I could just ask you

[@jj74qformerlyjailbreak3]

107 Juan O Savin. Get To Know Him. ❤️ And 💡 “or this case LED” 😂

[@g-code]

This is fantastic!!! Awesome job.

[@brent19731]

Watch AVE, he will tell you how to get your camera to FOCUS

[@benwinkel]

"FOCUS you F#ck!!"

[@mattantonelli4273]

great work man

[@sonnylou8087]

I do have a question but it’s not about your strobe light, I have an old realistic sa-1000 integrated stereo amplifier that won’t power up, the transformer has many output taps going to the board, I have not checked for voltages yet because I’m working on another project right now, do you think maybe by some chance it could be a diode in the power supply section or is it possible a bad cap? It’s all original and no one has been inside of it but it is exstreamly dirty, a lot of dust all over everything, what would you suggest? To make matters worse I can’t find a schematic for it any were, I hate to throw it out because I believe it’s something simple, just for the hell of it I thought you may have an idea we’re to start.

[@learnelectronics]

All of those things are possible. Start from the input, trace the power, component to component until you find where it stops. There's your culprit. That being said, given the age; electrolytic capacitors are high on the list of suspects.

[@anandswami3028]

can you provide circuits diagram pls

[@heed7496]

Why did you have to put the mosfet in when it already worked with the green led?

[@learnelectronics]

That 1 watt LED needs way too much current for the IC to source.

[@eddiekilby]

Always loved the 555

[@alanparadise3139]

Now you should do a few circuits using it as a one- shot with the 555 timer. Love these kind of videos with the 555 timer. Was that timer a 555p cmos or TTL

[@learnelectronics]

Ttl

[@alanparadise3139]

@@learnelectronics Ok thanks for replying And Ttl

[@PawOfRizzo]

Nice vid and project. Thanks!

[@sachinkokate5060]

Circuit diagram nahi details one by one nahi to kay samj me aaega

[@michaelpadovani9566]

This is great! I have a bunch of 555's and this is a great project. Just to clarify - you didn't use the BJT due to current constraints (no other reason)?

[@learnelectronics]

The BJT doesnt switch fast enough either

[@michaelpadovani9566]

@@learnelectronics ahh okay thx

[@melplishka5978]

Hey my friend can u put schematics plz. Great vids bud , much appreciated.

[@thetooginator153]

Great tutorial! Thanks!

[@skinnymouse1410]

Hey Paul!!! Thanks for the great videos!!! I got a couple of noob questions... Why an N-Channel Mosfet instead of a BJT for the low-side switch?? Also, how exactly are you limiting the current to the LED to 350mA? Where is the current limiting resistor??

[@learnelectronics]

BJT doesnt switch fast enough. I'm limiting current with my power supply.

[@skinnymouse1410]

Paul, thanks for the quick reply!

[@cjdelphi]

you can use a 2n2222 bjt up to about 400ma without too much heat, and a resistor to limit the current

[@muhammadsayed59]

What the max freq we can get from it??

[@bollie9752]

06:33 was the resistor in row 25 instead of 24?

[@debunkified]

What no schematic? FYI I scan through the entire video in like 2 seconds and saw that there was absolutely no schematic, which shows how to build it with just a glance.

[@darkvoidinfinity9810]

I want to make breathing effect using two 1w leds , anyone know how to do that ?

[@gplustree]

PWM signal to one led, inverse PWM signal to the other, vary the duty cycle at a frequency of maybe 400Hz?

[@asusasus2300]

merci , net et clair 👍

[@sachinkokate5060]

circuit diagram send kije ye with transistor than misfit n chanel

[@gunnaralv]

None of my business, but since I really like your videos, I will say it as it is. Read about your heart condition, and for the last years mounting evidence towards great benefits of plant-based diets, in reversing many illnesses and becoming really healthy, I was hoping you would check out this matter. Maybe it sounds strange, but you're a smart guy and I bet you would be interested. Really want you to stay here and keep up your good work.

[@neilgroves3592]

Why no current limiting resistor for the LED?

[@learnelectronics]

I limited it through the power supply.

[@melplishka5978]

It’s faster than the frame rate of the camera lol.

[@Aurora-xc8gw]

What is the purpose of the MOSFIT?

[@learnelectronics]

It's a switch. It switches the higher current needed by the LED and keeps it away from the sensitive IC.

[@Aurora-xc8gw]

@@learnelectronics hey, thank you for the explanation!

[@certified-forklifter]

nice

[@weerobot]

Arduino Feels like Cheating..lol

[@JNET_Reloaded]

Skip to @5:00 Minutes in!

[@FreedomRiderGarage3168]

if you're going to give a video demonstration, you should reveal the value numbers of the components you are using in your project, and no I am not happy with this video...

[@learnelectronics]

Then I would invite you to do your Youtubing elsewhere. Happy holidays. 🎄

[@FreedomRiderGarage3168]

@@learnelectronics and I will gladly unsubscribe from your channel happy holidays...

[@carlosmunoz4466]

If are capable of constructing something real cool. How come you can't fix the audio on your videos?