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.
Contents
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
36 Watt Current Controlled Strobe LED Light
This 36 watt LED strobe light circuit with current control feature was requested by one of the dedicated readers of the website, Mr. Rohit.
The design idea can be learned from the following explnation:
I am trying to make a fast flash LED strobe light like the ones used by cameramen for photography. I have seen some circuits on your website regarding LEDs like constant current driver, powering high wattage LED lights, LED strobe light. However, I think my application is a combination of these projects.
So what I want to do is power 18W or 36W LEDs for 1 microsecond flash and need a constant current driver so that every flash has the same intensity.
I hope to hear from you soon. Feel free to contact me if you have any questions by email or call me to discuss further
The complete circuit diagram for the 36 watt high power LED strobe light with current control feature can be witnessed in the following image:
Parts list
- All resistors are 1/4 watt 5% unless specified
- 1K = 4nos
- 330 ohms = 1no
- 56K = 1no
- 100k preset = 1no
- RX = as given in the diagram
- Capacitors
- 10uF/25V Electrolytic = 2nos
- Transistors
- BC547 = 2nos
- TIP142 = 1no
- 2N2222 = 1no
- RED LED = 5mm 20mA type
- PowerLED = 12V, below 5 amps.
Have Questions? Please Comment below to Solve your Queries! Comments must be Related to the above Topic!!
Hi Swagatam,
In the 1st circuit, I want to use a 3.7V Li-Ion battery.
What changes do I have to do?
Hi Nelio, to use 3.7V in the first circuit you can remove the 330 ohms and connect the positive directly with the circuit. However, now you can use only one LED, and make sure to use a 100 ohm resistor in series with the LED.
Also, the preset is wrongly shown as 10K preset, it must be a 100K preset instead.
Hi Swagatam,
Ok.
Thank You
Best Regards.
You are welcome Nelio!
Hello, thanks for your circuit, and your explications, I’m planning to use strobe lights in my motorcycle, and I think your circuit will work, but my question is, do I need to use several circuits for each one of the bulbs, or one board can be used for the four bulbs.
Thanks in advance
Hi, glad you liked the circuit. You can use a single circuit to drive all the 4 bulbs, which will then strobe simultaneously.
Hi, I’m planning to build the circuit in the next days, I hope works fine. You’re doing a good job with this webpage. Thanks again.
My pleasure Arnold, all the best to you!
Mr. Swagatam, I built a schematic of this in EasyEDA (not sure if you would like a copy of it) and put together a prototype of the schematic on a cheap breadboard off amazon. It works! (after a few hours of blundering attempts). The issue that I have is that the 18 watt LED light that I am using is extremely dim. My power supply says that is it only drawing 0.036 amps and less then .5 watts @ 12.6 vdc. When hooked up without the strobe circuit the light draws 1.2 amps and 15 watts @ 12.6 vdc. Any… Read more »
Hi Donald, is the driver transistor which powers the LED heating up too much? If it is heating up then it might blow off and cause the LED to be dim, if not then there could be a fault in your connections. If everything else is in good order, there can be only 3 reasons for the LED to get dim 1) The LED itself gets damaged due to over heating. 2) Transistor over heats and gets damaged, 3) Power supply fails to provide the required amount of current. It would be better to assemble the circuit by soldering instead… Read more »
Mr. Swagatam,
Thank you for sticking with me as I am working this thru.
Although I have not soldered it all together (I’m still working on that skill) I have purchased much better-quality components and have the strobe light working at 5 watts. (about a third of what it operates at without the circuit).
I have noticed that the TIP142 Transistor is getting hot after a few moments of operation. Do you think that has something to do with it?
Thanks again!
Donald
Hi Donald,
5 watts at 12V means the current will be = 5 / 12 = around 400 mA. This current is quite less for the TIP142 since it is rated to handle 10 amp current.
Are you sure the transistors are original and not duplicate.
Anyway you can consider adding a heatsink to the transistor if it is getting hot as the last resort.
As always sir, thank you for your advice!
My pleasure Donald.
Swagatam,
Thank you again for your help and quick response!
Could you enlighten me on the purpose of the “RED LED = 5mm 20mA type”?
Also, please pardon my ignorance, but what units is the “RX=.6/led current” in?
If I understand this correctly it would be .6 / 1.5amps = 0.4 somethings….Would this be a resister of 400Ω?
Thanks Again!
Hi Donald,
The red led is just an indicator LED which will flash along with the main LED.
RX is the current limiter resistor.
Yes your calculations are correct, but the result is a 0.4 Ohm resistor, not a 400 ohm
wattage of the resistor will be 0.6 x 1.5 = 0.9 watts or simply a 1 watt.
Thank you sir!
Mr. Swagatam, I am new to working with circuit boards and I find your work both fascinating and helpful. I am trying to create a security “blind light” that goes off with an alarm on a 12v system. I am using a 18watt led light that draws about 1.5 amps but would like the option to add an additional light for a total of 3amps/ 36 watts. I seems to me that your last diagram is precisely what I am looking for. Is there any possibility that you could decode the image for me into a parts list. I would… Read more »
Thank you Donald,
You can definitely try the last design for your specified application
I have updated the parts list under the last diagram, as required by you. Hope it helps
Hi. I love the simplicity of what you’ve shown here and I’m hoping that I’m just being simple in my turn when looking at the diagrams. I’m trying to make the strobe circuit for mains power to run the lamp on top of a full size police box (AKA TARDIS from Dr Who – I know, I know……). Anyway, I get most of the diagram for the mains powered lamp alternative except for the positive and earth wires. Do I need to add additional power into the circuit at those points or does it not already use the mains shown… Read more »
Hi, thank you, and glad you liked the post! I guess you are referring to the following diagram:
Yes you will have to apply a DC between 5 and 12V across the (+) and the ground lines. The mains power is used only to drive the lamp through the triac. The transistor circuit will require an external DC to operate.
ok Swagatam, The reason I ask for connecting the SMDs without soldering, is because I have heard there is some kind of special glue to do the job. You understand there is a tedious work to solder these tiny components together especially for a hobbyist. One more thing. Can I use those I already have, yellow SMD LED’s [0402 warm white] are coming pre-wired, or should I use any other type of LED’s? And how I can identify the polarity +/- of those components [resistors, capacitors, transistors] etc., to complete the circuit you suggest? Or it does not matter, I… Read more »
Hi Pat, I have no idea about how SMDs can be glued, soldering is perhaps a must for proper connections. You can use any 20 mA LEDs for optimum brightness. Resistors do not have polarity they can be connected any way round, only the LEDs and the electrolytic capacitors have polarity….I think you can easily find the information by doing an online search…there’s plenty of information available. To ensure that the circuit works regardless of the input DC polarity, you may have to supply the DC to the circuit via a bridge rectifier. The positive and negative terminals of the… Read more »
OK Swagatam thanks
Is any Bridge Rectifier with special electrical characteristics for this application I should buy? or any bridge rectifier will do the job.? Keep in mind I must build this circuit as small as possible.
I have order all components yesterday, except the bridge rectifiers.
I promise to send to you the results of the outcome.
Or my goof-ups……………!!!!
Hi Pat,
Any ordinary bridge rectifier will do. It may be SMD type or built using 4nos of 1N4148 diodes.
You can surely send me the results, hope it works for you as per the expectations.
Thank you Swagatam,
I have some old SMD Bridge Rectifiers (remove them from an old board) without the marks + and – on them.
Is any way to identify those marks +/- on these components by using a continuity check?
So I can use them instead of ordering new ones?
Thanks
Pat
No problem Pat, Yes you can use it. You may have to check each diode inside the bridge with a multimeter, and with some effort find out which are the two ends that have two anodes joined together and which are the two ends that have two cathodes joined together
Thanks Swagatam
I do appreciate ALL your help.
Waiting for the parts to arrive.
Pat
You are most welcome Pat!
Hi Swagatam, Just run to your site and I wonder if you can help me converting a strobe LED light made for bike safety at night, using two of those round 3V batteries, to my DC or DCC HO locomotives that use 7 to 19 DC Volts. In other words is any way to modify/bypass the 3 way push button switch (“ON-study lit”, “slow blinking” and “strobe”), and install this tiny chip with LED light(s), to my locomotive and get activated without any buttons to push, but once I apply power to the rail tracks and ONLY in the “strobe”… Read more »
Hi Pat,
It can be difficult to modify the existing circuit without actually seeing its circuit diagram. If you are willing to build a new strobe light then I would recommend the first circuit which is a tested design, and quite easy to build and implement. For 19 V, you may have to put another 330 ohm resistor in series with the LEDs, if two LEDs are used in series. For a single LEd use a 1K series resistor.
Thank you Swagatam for your reply. Now to understand as I wrote the supply voltage is various from 7DCV to 19DCV. There is a transformer that regulates the voltage to the tracks accordingly to how fast of the locomotives run. So, the additional 330 ohm resistor should be between the two LED’s? For one LED you advise me to use1K resistor, instead of 330 ohm? Because of limited space I have inside the loco shell one more question. Is there any way to connect the SMD’s without soldering the parts, so to create a very tiny circuit? Thanks in advance… Read more »
Hi Pat, that’s correct, if 19V is the maximum that the circuit has to tolerate then you will have to put an additional 330 ohms in series with the LEDs (if two are used), or a 1K resistor if a single LED is used.
SMDs parts can be used, and that will allow you to get a very tiny little circuit. SMD will require soldering, they cannot be connected without soldering.
I need to make an array of 300 LED of 660nm chips of 0.5W each. And, I want that the full array can be strobed at the frequency of 1MHz, producing ON pulses of the minimum 1microsecond. Can you please suggest the kind of LED’s and the driving circuit best suitable for this application?
I think you should modify the last concept from the above article for your application. You can adjust the output frequency to the desired levels by adjusting the capacitor values suitably.
Thank you for all the wonderful designs. I’m interested in turning FEIT Electric WLR2000/2/RP LED work lights into strobe lights to humanely drive away unwanted squatters (squirrels and mice) in our attic. These white LED lights have the needed brightness but they are equipped with internal battery packs. I’d like to remove the battery packs and directly control them with one of your circuits. Please advise which of these circuits will be suitable for this application. Thank you.
You are welcome, can you please provide the voltage and current specifications of the LED module that you have mentioned? I will try to figure it out.
That LED module will probably not work since it has an internal non-replaceable Li-ion battery. I have found another device that fits into a 110V E26 light bulb socket and is rated at 120V/60Hz/80W so I will need a circuit in line with the switch. The circuit itself may be powered by a lower voltage (5V?) USB power supply if needed.
OK, in that case the circuit using the triac will work, but it won’t be isolated from mains AC, and therefore USB would be also floating with AC mains. To avoid this an opto coupler might be required between the triac gate and the DC circuit, but that would make the design much complex.
Thank you. Perhaps I didn’t explain clearly, I’m thinking the circuit you provided for Lloyd Chesney’s application above would work for me since my 80W LED light is powered by 110V. I assume this circuit can drive an 80W LED lamp. What power 12V power supply should I use for this circuit.
What’s the part number for 12V relay and the red & blue diodes connected to the 1K resistors on terminal 3 of IC 555?
What change should be made to adjust the strobe flashing frequency?
OK got it, however a relay based strobe light may not be a good idea, since that may subject the relay to a lot of wear and tear, due to rapid switching.
If you want to use it, you can try it. The relay can be any 12V relay with coil resistance of around 400 ohms
The 12V DC can be from any small 12V adapter.
R2 and R1 both can be experimented to adjust the strobe.
Thank you for all the examples. First I am hoping someone has a suggestions for a real world need for many of our elderly family members living in a standalone housing developments. I want to find/make a light switch to replace a conman on/off light switch. I want it to switch to have two operating states, one constant on – for everyday use and a second operating state of flashing to help emergency responder’s to find them quickly. Please let know if you have ideas or know of a product that can do this.
Glad you liked the ideas. Here’s a diagram which can be used for fulfilling the mentioned application:
Hi Swagatam
Thanks for your reply
I’m using the 2N2222 transistors only and are the parts shown in the second diagram the same as the parts list shown further down in this article after the fifth diagram
Thanks
Regards
Vee
That’s fine Vee,
2N2222 will be able to handle higher numbers of LEDs. Instead of using two potentiometers you can use just one, and replace the other one with a fixed resistor.
Hi Swagatam
In your first and second circuit diagram using a 12 volt supply how many white LED’s can I use in series or series//parallel
Regards
Vee
Hi Vee,
In the first diagram due to the presence of the series 330 Ohm with the positive line, you cannot use more than 6 LEDs (2 strings of 3 LEDs, in parallel)
However, in the second diagram you can use more than 12 LEDs (4 strings of 3 LEDs, in parallel, with series resistor of 1K on each string). You can increase the number even more by replacing the BC547 with 2N2222 or 8050 transistor.
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… Read more »
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… Read more »
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.