If you feel strobe lights very interesting but are disappointed by the fact that these wonderful light effects can be produced only through complex xenon tube then probably you are quite mistaken.
It is very much possible to make any light a strobe light if you are equipped with a proper driving circuit capable of handling different lighting devices to generate the desired strobe light effect.
The present article shows how a circuit as basic as a multivibrator may be modified in different ways and made compatible with ordinary bulbs, lasers, LEDs to produce spectacular light pulses.
A strobe light may be used for warning, scientific analysis or as an entertainment device, whatever may be the application the effects are simply dazzling. In fact it is possible to make any light a strobe light through a proper driving circuit. Explained with Circuit Diagrams.
Difference Between Flashing and Strobing
A light when made to blink or flash indeed looks pretty eye-catching and that’s the reason why they are used in number of places as a warning device or for decorations.
However a strobe light in particular may also be considered a flashing light yet is uniquely different from ordinary light flashers. Unlike them in a strobe light the ON/OFF pattern is so optimized that it produces sharp dazzling pulsed flashes of light.
There’s no doubt why they are mostly used in conjunction with fast music to enhance a party mood. Nowadays green lasers are being popularly used as a strobing device in party halls and gatherings and have become hot favorite among the new generation.
Whether it’s LEDs, lasers or an ordinary filament bulb, all can be made to flash or rather strobe using an electronic circuit capable of producing the required pulsed switching in the connected lighting element. Here we will see how we can make any light a strobe light using a simple electronic circuit.
The following section will acquaint you with the circuit details. Let’s go through it.
Pulsating any Light to Produce Strobing Effect
Through one of my previous articles we came across a nice little circuit able to produce interesting strobe effects over a few of the connected LEDs.
But this circuit is only suitable for driving low power LEDs and thus cannot be applied to illuminate big areas and premises.
The proposed circuit allows you to drive not only LEDs but also powerful lighting agents like incandescent bulbs, lasers, CFLs etc.
The first diagram shows the most basic form of a multivibrator circuit using transistors as the main active components. The connected LEDs can be made to strobe by suitably adjusting the two potentiometers VR1 and VR2.
UPDATE:
I have explained a few transistorized strobe light circuits in this article, however the below shown design is the easiest one and is tested by me. So you can begin with this design, and customize it as per your own preference and liking.
Video Illustration
The above discussed simple design can be further modified as explained below for greater control and refined outputs.
The above circuit forms the base for all the following circuits through some suitable modifications and additions.
Using a Flashlight Lamp as Strobe Light
For example if you want to illuminate and pulsate a small torch bulb using it, you would just need to do the simple modifications as shown in the second diagram.
Here by adding a PNP power transistor and triggering it through the collector of T2, a torch bulb is easily made to strobe. Off course, optimum effect is achieved only through proper adjustment of the two Pots.
As already discussed already in the previous section, green laser pointers are pretty popular nowadays; the diagram illustrated shows a simple method of converting the above circuit into a pulsating green laser pointer strobe light.
Here the zener diode along with the transistor works like a constant voltage circuit ensuring that the laser pointer is never supplied with a voltage higher than its maximum rating.
This also ensures that the current to the laser can also never exceed the rated value.
This the zener and the transistor functions like a constant voltage and also an indirect constant current driver for the laser.
Using AC 220V or 120V Lamp as Strobe Light
The next diagram shows how an AC mains lamp may be used as a strobing light source using the above circuit. Here a triac forms the main switching component receiving the required gate pulses from T2’s collector.
Thus we see that through the above circuit designs it becomes very easy to make any light a strobe light simply by doing the relevant modifications within a simple transistor based circuit as exlained in the above examples.
Parts List
- R1, R4, R5 = 680 Ohms,
- R2, R3 = 10K
- VR1, VR2 = 100K pot
- T1, T2 = BC547,
- T3, T4 = BC557
- C1, C2 = 10uF/25V
- Triac = BT136
- LEDs = as per choice
Police Strobe Light Circuit
For the slow astable use the following parts:
- R1, R4 = 680 Ω
- R2, R3 = 18K
- C1 = 100 μF
- C2 = 100 μF
- T1, T2 = BC547
For the Fast astable use the following parts
- R1, R4 = 680 Ω
- R2, R3 = 10K
- preset = 100K
- C1 = 47 μF
- C2 = 47 μF
- T1, T2 = BC547
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Hello and thank you for your work and postings here.
I am looking to build a single (1) LED strobe (not flash or blink) that runs on 5VDC where I can control the pulse rate. I found this video and it looks to be the right time between nice defined strobes in the video but it was not when I built it, also the voltage is 12v not the required 5v I need. Could you please show me how to redesign this for 5V with the ability to control the strobe rate (looking for 1-1.5 seconds) please. Thank you.
You will need 12V for this circuit, 5V will not work, and it cannot be modified for 5V
https://www.homemade-circuits.com/how-to-make-single-transistor-led/
Hello,I would like a Simple as possible ?
Circuit diagram for a Variable frequency Strobe light using leds ?
I want to use it for various Physics experiments ?
Meldes,Water drop,Etc,etc
Thank you
Hi, you can try the circuit design which is shown in the video…
sir, is this the kind of capacitor your mean I should put for T1 and T2 Ceramic Capacitor 103 (0.01uF),
Capacitor 0.01uF = 10nF, code is
103/ 103z. pls don’t be bore with my question.
It is to be put in the calculator software for time T1, T2 slots.
sir thank u for your responds but I didn’t understand what u mean, but let me state it this way connect the positive of the astable circuit to the battery positive through a 100k ohm resistor and connect a 100/25v capacitor across the positive terminal of the circuit. and connect a IN4007 diode paraller to the capacitor which is the negative of the diode to positive line. positive of the diode to negative line,pls is this what u mean and as for the transistor astable calculator software, can you give me clue on how to make use of it .I will appreciate.
Hello younkking, It should be 100 ohms, not 100k. And the diode should be a 12V zener, not 1N4007.
Please refer to the following circuit, and check how the circuit side configured with the above mentioned parameters.
https://www.homemade-circuits.com/1500-watt-pwm-sinewave-inverter-circuit/
In the astable put 0.01 for T1, and T2, rest can be as already filled
good evening sir, I used this first circuit as an inverter which is light strobe circuit. the gate of the MOSFET (irf540)was connected to the collector .drain to the left side of the transformer and the other drain to the right side of the transformer while the center tap is for battery positive.but on powering the circuit, it light up 60 watts bulb for a seconds before blowing off bc547 transistor .the only thing I change in the circuit is 100k fixed resistors in place of preset. now what could caused the problem. does it mean that the MOSFET is not getting the need frequency or does it mean that the two halve wave is oscillating at the same time .cos the two led in your circuit is blinking at the same rate and I wish i know how to upload the video of this circuit so u can see the blinking rate before this issue arise.pls your respond is needed.
Hello youngking, it could have happened due to the transformers’s reverse EMF spike. Connect the positive of the astable circuit to the battery positive through a 100 ohm resistor, and connect a 100uF/25V capacitor across the +/- terminals of the circuit, and also connect a 1N4007 diode parallel to this capacitor, cathode to the positive line, anode to the negative.
…and you can use this software to set the frequency at 50 Hz:
https://www.homemade-circuits.com/transistor-astable-multivibrator-amv-calculator/
Thank you sir, i will still go back and apply what you said whenever i have time
hello sir, thanks for your effort so far . i went through the second diagram concerning where the gate should be connencted is in between R1 AND R4 or before R1 and R4 . the link you shown me about increasing the frequency, i scean through it yet i didn’t figure out anything. pls i really need your help on this few question above.
You can change the capacitor values to change the frequency. The mosfet does not need to be Darlington. Mosfet gate can be connected directly to the collectors.
since you have already tested the circuit with LEDs, the circuit has to oscillate and the transformer will make a low buzzing sound that will confirm its oscillating.
sir pls don’t be bore with my question. 1. so the gate of the mosfet will be connected to the output of this circuit where the Led bulb is .2. like you mention darlington iRf540 should be used can’t iRf3205 be use for the job. 3. the circuit was built with 9v battery, so what if one use 12v battery won’t it blow the whole circuit .4. what and what can be change in other to increase the frequency, because what i use is fixed resistor which 100k. 5. the diode you mention which side will be connected to the gate nor the source. 6. how will i know that the transformer is oscillating. I’m waiting for Ur respond
youngking,
please go to this article:
https://www.homemade-circuits.com/mini-50-watt-mosfet-inverter-circuit/
and check the second diagram for the details.
for frequency change you can refer to the following page:
https://www.homemade-circuits.com/transistor-astable-multivibrator-amv-calculator/
sir i build this first circuit and it work, so how can i use it as an inverter. sorry to quote you . I would recommend you to first build a basic astable circuit with LEDs as shown in the first diagram from this article and then apply it or the inverter function: don’t use VR1, use 100K for the base resistors initially so what next to do thanks.
Youngking, if you have confirmed with LEDs, so now you can link the Darlington power BJT or mosfet with the two halves of the astable. I would recommend IRF540 which can be directly linked with the collectors of the respective BJTs. Make sure to attach protection diodes across the D/S of the mosfets.
After this switch ON power and you’d find the transformer oscillating at the set slow rate, may be 1Hz. Now you can gradually increase the frequency to 50Hz and get the required results.
Swagatam,
Could you add the Resister value for the two resistors going to the TIP 122 Transistors? Thank you!
Todd
You can use any resistor between 1K and 10K since the TIP122 is a high gain transistor. I have not shown resistors for the LEDs, assuming they are 12V rated or they have their own internal protections.
Hello sir, I cant get a 100k pot in our local market. I got a rotary switch having six fixed similar resistors (switch used in small emergency led light pack as dimmer). Can I use this switch as a pot buy replacing all six resistor with 15k resistor (each step will increased by 15k ohm as switch rotate) for above circuit???
Hello Nitin, you can use the pot or the rotary switch with 15K resistors, both will work.
Hello sir, I want know why two pot are used?
Can use one fixed and one pot instead???
You can use one pot in the manner shown here:
https://www.homemade-circuits.com/make-this-electronic-mosquito-repeller/
Hello sir, can I use this strobe light circuit as a pwm for small dc motor ???
Hi Nitin, yes you can use, try the second design.
Does anyone have a good place to get the parts in order to make this? Also, approximately how much would the parts to make this cost? I was thinking more of the 120V version. The 120V version would allow me to take a bank of LEDs that is connected to 120V plug I plug into the wall…and in theory if I plug it into this circuit then this device into the wall, would cause that bank of LEDs to flash rather than be on steady, right?
Hi Wesley, In India the cost of the parts would be less than a dollar, not sure about other countries. Yes the last circuit would allow you to illuminate lamps specified to work with 120V AC
You can buy the parts from any online electronic spare parts store, although the shipping charges could be 20 times higher than the actual cost of the parts
Sir,
I have successfully built the 2nd circuit i it works but how can i make it blink slower and i have set the VR2 in maximum and its still blinking fast. Do i have to increase the 100k pot? thanks..
Paul
Paul, increase the two capacitors values proportionately, that will slow down the blinking rate….
Sir can i replace VR1 with a fixed resistor and can you suggest what values of resistor can i replace..
Thank you..
Paul
you can directly connect R3/R2 ends with the positive line, but make sure these are at least 22K
BTW Sir,
In the second circuit can i add a piezo buzzer? And can i remove the two leds connected at R4?
Thanks again.
Paul
yes you can remove the LeDs, and also add a buzzer in parallel with R1 or R4…the buzzer should be a piezo buzzer ready to use
Thank you very for the quick response
Thank you for helping us newbies..
Paul
you are welcome Paul!
Hello,
Which of this circuit well power 12v LED to use as signal blinker for a motorcycle? And as replacement for my broken flasher in my motorcycle?
Thanks..
Paul
you can use the second circuit for your purpose, replace the bulb with your 12 LED connections
Hi Sir, I am a begginer in this and don't even know about the symbols or short forms of parts used in the schematic diagram. So, please kindly help me in this. I am interested in making a simple Led strobe with simple parts. So plz sir kindly send me circuit diagram with full names of parts and their values. Bcoz i can't understand above circuits of strobe lights.I will be very thankful to you for helping me.
Hi Anshuman, here's the parts list for you
Parts List
RESISTORS, 1/4 WATT
R1, R4, R5 = 680 Ohms,
R2, R3 = 10K
POTENTIOMETER
VR1, VR2 = 100K pot
TRANSISTORS
T1, T2 = BC547,
T3, T4 = BC557
CAPACITORS (ELECTROLYTIC)
C1, C2 = 10uF/25V
Triac = BT136
LEDs = as per choice
Hii sir, I am interested in using your circuit for speed measurement( Application of Stroboscope) so will it work for flashing light at high frequency and provide sharp light pulses at variable rate I.e at 0.5 ms to 100 ms? Please It'll be so kind if u can help me…
Hi Yakub, yes it will definitely work…you can try the second design from top….make sure to connect a 1N4007 diode in series with the emitter of the PNP transistor to ensure total switch OFF of the connected lamp
Hi! i´m try to use this for an OFF/ROAD led cubes in my vehicle andmanage to make it work eleminating "R4" but still the leds do not illuminate to their maximun capacity and sometimes they stop being strobes, these led cubes are 12v but do not specifies the watts, Iknow they are hig wattage, could you please help me with this dilemma? thanks in advance
I use 1/2w resistance
Please try the second circuit from top, replace the bulb with your LED, but make sure to add a calculated resistor in series otherwise your LED and the PNP transistor both might get damaged
you can also try the third circuit from top
T3 should be TIP127 or as per the LED current
HI, finally I know that the LED cubes are 12v 18w and i´m going to use two LED cubes, if I use the second circuit with the "TIP127" is going to work?
Hi, yes you can use the second circuit for getting the intended results.
use a large heatsink for TIP127
the pulse width can be controlled through the shown pot, and the frequency by changing the capacitor values.
I've noticed that some strobe circuits are better than others. Better, I mean sharper transient response. I'm looking at the kind used in the strobascope applications. https://en.wikipedia.org/wiki/Stroboscope
I've created art using this concept and tried various strobes. The conventual novelty units work best, cell phone stobe apps do not. They seem to blur the visuals the conventual are crisp.
Can you tell me why and also point me in the direction of concept to make a working circuit with sharper transient response?
Thanks!
Did you try a simple PWM IC 555 based stroboscope circuit? or you can also try a NAND gate PWM circuit for generating absolutely sharp turn ON/OFF strobe effects
I'm interested in flashing an LED 80-100 times per second. How can I accomplish this? Thank you!! jasona111988@gmail.com
reduce C1/C2 and VR1/VR2 values…
Please give a suggestion..
Hey i tried 1st one and works perfect on 9v battery and if i connect them in my bike the bc547 gets heated and no blinking in bulbs..
use 1k for R1, R4 and if possible replace the BC547 transistors with 2N2222….
Thanks and it worked great..how to make them to blink twice one and twice other if we connecting them on other arm as you said above in comment?
For blinking it twice on each channel you may have to build another identical circuit, but without the collector resistors.
connect the collectors at the junction of the respective resistor and LED of the on each channel of the previous circuit.
adjust the new circuit to blink faster so that two blinks are injected on the LeDs.
…make sure the resistor of the LED is connected with the positive and the LED with the collector for implementing the above integration.
if you have the LED connected to positive and resistor to the collector, just swap the positions.
Hey bro when i connected this circuit the led is not blinking instead glowing steady also bc547 gets heated much
What should i do?also is it ok to replace the two led with led strip?
led strips rated to work on 12V can be connected with the above circuit, change the transistors and check again, it seems the transistors are blown, replace them with 2N2222 or 8050
Yeah u r ryt it blown out…now works perfect as per ur diagram but brightness is low wt to do for it?i hv replaced two led and 680ohms into led strip..whats advantage of 2n2222 and 8050?how to check blown transistor? Btwn thnkz a lot finally my bike blinking:-)
LED strips already have internal resistors so may be R1, R4 can be eliminated from the circuit.
2N2222 or 8050 are have higher current rating will not become warm or get damaged with higher current or voltages.
…..2N2222 or 8050 have higher current rating therefore will not become warm or get damaged with higher current or voltages.
R1too it won't affect ics?btwn does it is reduce the brightness of the led due to less current? I already removed r4.. Does it works on 24v circuit too? Thnkz for the kind reply 🙂
sorry No, if you are using only the R4 channel then you should NOT remove R1 otherwise T1 will blow off.
yes you can 24V also but only if the strips are also rated at 24V
Cool super works by u 🙂 can u lend me ur email id i have some queries and i need to send pics?
thanks Bro! here's my email ID hitman2008@live.in
Hello
Just came across your blog. Are these circuits free to use or there are any copyright issues???
Hello, Practical use is free and allowed, but publishing elsewhere could be an infringement
….T1, T2 = 2N2222
Hi, the third circuit would perfectly suit your need. LS1 may be replaced with the LED,
T4 = 2N2907
T3 = TIP32
R6 = 0.6/0.5 = 1.2 ohm it's the current limit for limiting the current to 500mA
rest everything would be as per the given parts list.
I'm an amateur with dc electrical circuits but quite fascinated and eager to try. I have been throwing around the idea of trying to build an electric fence charger. I think your strobe circuit would work. Would you agree? I need a constant on/off/on/off power source capable of delivering a high voltage shock while still not being strong enough to deliver permanent damage. These are the specs on a 2 mile fence charger.
Item Specifications:
115 volt, 60 cycle
AC input/output
0.5 joule output
Pulsed output
Output voltage no load is 2300 volts
2 mile range
I would like to build a tiny fence charger that would energize only about 50 ft. What do you think…is it possible?
Yes the above circuit can be used with a fence charger for triggering short pulses, I have discussed one similar application which employs a 555IC producing identical results which also has an adjustable pulse rate feature, you can refer to the following two articles for getting an idea regarding the concepts:
https://homemade-circuits.com/2012/05/make-this-solar-powered-fence-charger.html
https://homemade-circuits.com/2011/12/homemade-fence-charger-energizer.html
….for making it tiny you can replace the ignition coil suggested in the above links with a small ferrite core transformer as used in mosquito zappers.
I got a few questions for you. I am a volunteer fireman and I'm thinking about using your design here for some emergency lighting for my jeep. How could i wire in 2 strips of LEDs both containing 6 LEDs, and make them alternate? Also can this circuit work on a 12v DC circuit?
If you can email me about this I'm very interested in learning more.
The above circuit will work with 12V supply.
You can use the first circuit with the following mods:
Connect LED on the other arm also but use three LED in the series.
You can accommodate another series of 3 on each arm with separate individual series resistors as done with the previous series, in this way you have six LEDs on each side.
If you have readymade strips with the above series built in, you can simply connect each strip directly between the collector and the positive of the transistor on each arm..R1 and R4 will not be required in that case.
he parts list would be:
R1, R4(for the first option) = 150 ohms
R2, R3 = 68K (the VR1/2 are not required, you can remove them and connect R2 R3 directly with the positive rail)
Capacitors = 10uF/25V
Transistors = BC547
Hi, I followed your first circuit diagram on a breadboard and it worked perfectly. I'm truing to make a 12v circuit using 12 festoon LEDs with inbuilt resistors. I can't quite work out from your written description what to do. Can you draw it?
Hi, if the LEDs are rated to work with 12V, you may connect 6 of them in parallel across each transistor collector arm, they should work, but the transistor may need an upgradation and may be replaced with 8050
Hi Swagtam, OK, getting closer. My previous post probably didn't accurately describe what I'm trying to do. I have a vehicle 12v festoon LED bulb that I want to rapidly blink. I originally didn't understand what you meant by connecting between collector and positive (I thought you meant the positive base of the transistor, and blew it up) but understand now that you meant the positive rail at the top of the circuit.
OK, so I have removed R1 and R4. R2 and R3 are still the original 10k ohm resistor and the trim pots are still there at 100k ohm. I wired in the 12v LEDs where the original 3v LEDs are in the 1st circuit. Now I get the LEDs to light up, and dim slightly with a tweak of on of the trim pots, but no blink.
Should I take out R2 and R3? Should they be replaced with a smaller ohm resistor? One last piece of info is that the 12v festoon LEDs measure 88.7 ohms across.
Any help would be appreciated.
Adam
Adam, yes making R2/R3 smaller will produce faster blinking rates so you can try replacing them with 1k resistors.
If the LEDs are not completely shutting off, the reason could be leaky caps or wrongly connected cap polarity.
If the caps are OK, you may try adding a series 50 ohm resistor with the LEDs to eliminate the issue or put 1N4007 diodes in series with the emitters of T1/T2