How to Make Car LED Chasing Tail Light, Brake Light Circuit

The circuit explained here is presented in response to a
request sent by one of the avid readers of this blog. The proposed circuit is of a sequential
LED light driver, especially designed to suit the application of a multipurpose
car tail light indicator.
The circuit is integrated to the brake switch and
works as a brake light, it’s also connected to the turn signal switches for
indicating the turning of the vehicle with chasing light patterns, and the
circuit can also be used just as an ordinary tail light warning indicator.

In order to successfully make the proposed car LED chasing tail light, brake light circuit, it will be important to first  understand the circuit functioning in details with the following

The CIRCUIT DIAGRAM can be divided into two sections, the first consists
of the LED driver stage, where the IC 4017 forms the main LED sequencer and is
configured in its usual counter/divider mode.
Only six channels of the IC 4017 have been used to avoid
lengthy sequencing patterns and crowding of the LEDs.
Two arrays of LED are taken from the above outputs such
that they β€œrun” in opposite directions when switched ON, however both the channels
are never run together since they are used for the LEFT, RIGHT turn indicator
purpose and therefore only the relevant side is switched ON depending upon the
vehicles turning side.
The IC 4060 is configured in its standard mode, as an
oscillator and is used for driving the IC 4017 with its clock signals. With
every rising peak of the clocks, the outputs of the IC 4017 shift from one pin
out to the next in the shown order, making the connected LED illuminate sequentially.
The pot associated with the IC 4060 may be used for
adjusting the sequencing speed as desired.

The LED stage consists of the LEDs arranged in a definite
sequencing pattern as discussed in above explanation. The LEDs are connected to
the IC 4017 outputs so that they are able to perform the intended sequencing or
chasing function.
The LEDs are also discretely wired up to the different vehicle
controls like the brake switch, the turn signal switches and an optional DIM
tail light switch.
When the brake switch is applied, the LEDs light up all
together brightly, indiacting the application of the brakes.
When one of the turn signal switches is switched ON, say for
example the LEFT turn signal is applied, the LED array positioned on the LEFT
portion starts sequencing from center, toward LEFT, indicating the intended moving
direction of the vehicle.  
The above function is repeated toward the RIGHT side by the
right portion LED array when the right signaling is made with the relevant
A couple of optional switches (S1) may also be included and wired up with
the LEDs as shown in the diagram. This provides a feature of operating the LEDs
as a dim tail light indicator which stays switched all the time with a
relatively lower brightness, however when the brakes are applied the LEDs light
up brightly.

The driver circuit is powered through the IC 7812 which is a voltage regulator and provides safe operating stabilized voltage to the circuit, irrespective of the input fluctuations.
In the above position, the turn signals will also work, but
is not recommended as the DIM light at the background may affect the signaling.

The following image shows the complete combined circuit design of the above discussed two stages:


A simplified and scaled down version of the above explained car chasing light circuit with brake light and park light can be witnessed below:

102 Replies to “How to Make Car LED Chasing Tail Light, Brake Light Circuit”

  1. B

    This is AMAZING! Thank you so much! I can't believe you did it so quickly, too!

    Just a few questions if I may:
    1: Is there a set limit of how many led's can be safely used with this?
    2: If the brakes are on, will the turn signals still operate or would the brakes being on override that function, keeping all of the led's lit constantly?
    3: Are the brake light switch and signal indicator switches providing the ground? Also why is "to brake light switch" on there in two different places?
    4: lastly – is there a particular type of LED you'd recommend. There are so many different types out there now, it's overwhelming for a laymen like myself.

    I apologize for what probably seem like stupid questions, but I want to make sure I have a good grasp of everything that's going on here before I even think about attempting this.

    Thank you, again, for the phenomenal work you did on this!

  2. Swagatam Post author

    Thanks very much B!

    Here are the answers to your questions:

    1)3 nos. per channel is the recommended quantity for any type or color of LEDs for optimum brightness.
    2) Applying brakes will override the chasing feature and the LEDs will remain lit as long as the brakes are ON.
    3)All the vehicle switches bring positive supply to the shown inputs, all the "brake switch" marked inputs can be made into a common terminal and connected to the brake switch.
    4) 5mm RED LEDs will be most suitable here, since we are using the circuit as a warning indicator.

    Your questions are all valid and I very much appreciate them.

    Thanks and Best Regards, keep in touch!

  3. B

    Thank you for replying so quickly, Swagatam. You are extremely helpful!

    I have one last question for you. I now know that 3 per channel is the recommended quantity of LED's, but is that the TOTAL number of LED's per channel, or just the number that should be run in series? Would you get the same brightness out of the LED's if you had four "clusters" (a "cluster" being 3 LED's run in series) of lights run in parallel per channel? Does what I'm saying make sense?

    The only reason I ask is my tail lights are rather large by today's standards and I think I might need to use more LED's to fill them properly.


  4. Swagatam Post author

    Hi B,

    I am not exactly sure regarding what will be the LED brightness if more numbers are added, however you can try connecting a couple of more strings in parallel to the existing string in each channel, don't forget to connect a series resistor with each string.
    You may reduce the series resistor value to 680 Ohms for getting more brightness.
    If you are using RED LEDs, make the series into 4 LEDs, that would add an extra LED to the string and help to increase the over all number of LEDs.


  5. B

    OK I lied… haha. I have one more quick question on this. Would you mind, terribly, providing a parts list as you have in other posts I've seen. I'd rather not have to ask, but I'm not entirely sure what all of these symbols mean. Also is there a specific pot which should be used in conjunction with IC 4060?

    Thank you again! I'll have to send you a video of this thing in action when it get's done!

  6. Swagatam Post author

    Hi B,
    The orange boxes are the resistors, the black arrow like symbols are the diodes, the BC547s are the transistors and the the three large squares are the ICs 4060, 4017 and 7812.
    All the diodes are 1N4007 or, 1N4148 will also do.
    The resistors values are printed over or near the orange boxes, you can find them easily, most of them are designated with the letter "K"
    The resistors are all 1/4 watt rated.
    The pot can be any standard type with three pins and a spindle, having the shown value.
    The parts dealer will know everything, you can take his help.
    The switches are two pin type, any make and size will do the job.
    It seems you are pretty new in the field, are you sure you can build this???
    Let's hope positively…. I'll wait for the video, wish you all the best.
    Thanks for posting!

  7. B

    Yes I am new to circuits like this, but I am positive that I can build this. If I have any trouble with anything during the build, my dad has experience with building circuits and he can lend a hand if the need should arise. I am excited to get started on it! I've always been a self taught and hands-on guy and this will be a great experience!

  8. B

    Hi again Swagatam. I tried to get a friend of mine to help me out with this as I didn't want to bother you any more about it, but it turns out he is out of the country for the next two months. I don't want to ask you to design another circuit since I already got more than I had hoped for with this one. But if you wouldn't mind, could you possibly take a look at the linked picture below and tell me if this idea would be do-able by modifying this circuit or if this would require a whole new setup. I would be most appreciative of any help you can give.

    I laid it out in such a way that the dim/bright switched lights would operate independently of the turn signals. I figured this would make the implementation of all the functions together easier. But as you see, there are over one hundred LED's which would make up this light. I did make it so the number of led's used is a multiple of four (as in 4 led's connected in series). The top three rows of led's would be strictly dim/bright. As in running/brake lights / hazard flasher. The bottom two rows are separated into 7 "banks" of led's and used strictly for the sequential turn signals. Lastly – I'm wondering if there is any way to use pots to independently control the brightness of the dim and bright settings? Anyways… If there's anything you can do to assist in this, I would very much appreciate it.

    I know this is a lot and if it's not something you would prefer to take on, I would certainly understand!

    Thank you so much either way! Oh – and here's the picture:

  9. Swagatam Post author

    Hi B,

    If the dim/bright LED section is kept entirely aloof from the sequencing LED section and operated independently then definitely your idea will work.
    The dim level of the LEDs can be controlled by making the 220 Ohm resistor variable or by replacing it by a pot.


    1. Zues 73 Nova

      I think I understand how this is working all the way up to the switch (S1) for dim control of the LEDs. I would definitely us a pot for this. I do need to use the (S1) for my application. The brake light and turn signal wire are the same wire at the tail light and the brake light is canceled in the turn signal switch. If I put the pot on the positive side and eliminated the brake light switch lead in that area of your schematic. Would this work? It appears that the LEDs would sequence one time for the brake and stay lit until the brake is released.

  10. Anonymous

    I’ve been looking for this for a few weeks and it looks great but I have a few ques
    1: what type (trimpot, cermet or rotary) and size pots ton replace ic 7818 and the 220 ohms r
    2: what switch should I use for the two at the bottom of the second image(push on/off, toggle threw, pushbutton (by the way what is the purpose for them?)
    3: can I replace the 1uF/25v with a 1uF/35v
    4: will the flashers from the turn signal bother the design or is it better to go striaght from the turn signal switch
    Thanks for the post and for any help given

    1. Swagatam Post author

      1. A trimpot will do
      2. any ordinary DPDT toggle switch
      3. 1uF/35V will do.
      4. Straight from turn signal switch and not from the flasher unit.

      Thanks and Regards.

  11. Anonymous

    dealing with the leds is kinda tricky due to the fact of the sodering in series, the diodes and resisters.
    but when dealing with the led max voltage, max continuos forward current and max peak forward current what do i go by to get to the resister i'm confused…..
    if the led is 3.6v max cont current is 30mA and the max peak current is 75mA and its 3 leds in series will 1k r work or 680ohm r to get the brightes glow
    cuase on line calculator recomends 18ohm or 47ohm r when doing the math
    sorry for being a pain just want to get the right resisters for the job


  12. Anonymous


    Does this work with ordinary tail light bulbs or does it have to be LED's? Thanks in advance for your help

  13. Ron Franklin

    Hello, I came across this via Google search. I am in the process of building a custom chopper and the shop that has my bike would like to run a set-up like this. I am not a circuit builder, where do I purchase the parts you used for this setup? I appreciate any input you can share.

  14. Fish

    I am currently bulding a setup like this for my car and found your circuit to be very helpful. my question is how can you configure it so that the sequential overrides the brake function?

    1. Swagatam

      You mean when the side signals are ON, the braking should not affect the sequencing?

      In that case you will have to do following mods:

      Introduce a TIP122 transistor in the circuit with its emitter connected to the common termination of all the 1N4007 diodes, connect the collector to supply positive, connect its base via a 1K resistor to the brake switch (to the cathode of the existing 1N4007 brake switch diode).

      Also connect its base directly to the collectors of the BC547 transistors via two individual 1N4007 diodes, the common anode of the two diodes will connect to the base of TIP122 and the cathodes will go separately to the collectors of the two BC547 transistors;)

  15. Jordan Cain

    I am interested in building this set up but I have one question. When your driving lights are on will the tail lights be dim and brighten when brakes are applied? Or is that what the dim switch is for?

    1. Swagatam Post author

      I think there's a slight mistake with the brake switch connection, there's no ground available to the LEDs when brakes are applied. I'll correct it and update the article soon….

    2. Swagatam Post author

      I am sorry, the circuit has no mistakes….. yes, if S1 is kept switched ON then while driving the LEDs will be dimly lit and will brighten up when brakes are applied.

  16. Anonymous

    Thank you so much for the great posting and diagrams. I am looking to create this circuit for my car. I think your response of Nov 29, 2012 defines what I want to accomplish, in that I want the turn signal indication to remain in an active sequencing mode even when the brakes are applied. The modifications you detail in your Nov 29 29 posting allows this to happen, true? If so, can you provide a diagram that shows the placement of these added components. Again, thank you.

    1. Swagatam Post author

      Thanks so much! appreciate your kind words.

      Actually the present work load is not allowing me to concentrate here, I wish I could do it immediately, yet I'll try to update the required diagram asap.

      Bets Regards.

  17. Anonymous

    Hi Swagatam,

    Merry Christmas to you and to all your followers.

    i make this circuit but i got a problem. when im turning on the signal left or right the LED is not sequencing? what could be the problem?


    1. Swagatam Post author

      Hi Mike,

      Merry Christmas to you too!

      Did you check the circuit on table before installing?

      You will need to check it manually through a 12 power supply before installing it.

      Connect the LED resistor common ends directly to ground and confirm whether the circuit is sequencing or not.


    2. Anonymous

      Hi Swagatam,

      i already test it connecting the resistor to the ground without the transistor. still the the same no sequence movement for the LED, all in light mode only like a break light.
      i check it also connecting the LED direct to IC 4017, the sequence mode is working.
      what would be the problem? is it something is missing?


    3. Swagatam Post author

      Hi Mike,

      Disconnect the diode common anode wire entirely from wherever you have connected it, then check.

      The LEDs are always ON means it's getting positive supply from the diode common anode, there cannot be any other reason for its continuous illumination.


    4. Anonymous

      Happy New Year Swagatam…

      Thanks, it is working now. i thought the diode going to the battery is for the park light. it was my mistake.
      i have a little problem, how can i make the signal much brighter?


    5. Anonymous

      Could you be more specific on the components. I tried to purchase the 4060, 4017, 7812 and BC547 components; however, some of these components have multiple suffixes. I would appreciate a specific listing of components and a possible source.

    6. Swagatam Post author

      I have provided the core numbers which are universally recognized, the suffixes are not important and can be ignored….the concerned dealer should know about all these, if he is unable to recognize them then it would be difficult for you.

  18. Jack Ripper

    Hi Swagatam,

    I just recently started to put this circut together and was wondering why a 555 wasnt used instead of the 4060 as it is somewhat of a simpler chip(less pins)? I also had a question as i seem to not be able to get it to sequence, i've tried all Things i could possibly think it could be and have tried the solutions on here as well with no luck any idea would be great.

    ps. i have a background in electronics and i'm about to say that the chips i have bought are defective(hopefully not).

    1. Swagatam Post author

      Hi Jack,

      IC 555 can also be used, no issues….. in fact any design that is able to generate the required clocks is perfect.

      IC 4060 has 10 outputs and we want to use only one out of them, so eliminate the remaining 9 pins from the the total 16 pins, becomes 7, means it's even simpler than a 555 which has 8 pins. Moreover it's highly accurate compared to 555.

      You could probably check the stages separately, first check whether pin14 of IC 4017 is getting the required clocks from IC4060.

      Then check the LED, diode polarity etc etc.

      The design is pretty straightforward and their shouldn't be much problems making it work.

  19. Toontje

    Hello Swagatam,
    I found this circuit and it is very helpfull in designing a set of custom tail/turn/brake lights for my '86 Monte Carlo SS.

    One question: do you think it is difficult to make the turn signal a bit different, I want my turn signal not as chasing led's (only one on at a time) but they have to switch on after eachother and stay on until the last one lights up. Then all switch off and repeat the sequence.

    One remark: to control the brightness difference between the tail light function and the turn/brake function, I'm going to use a led dimmer based on a 555 (basically by varying the duty cycle) instead of changing the current through the led's by changing the resistor.

  20. Chris Rose

    Great write up! I'm going to do this within the next couple of weekends.

    2 questions…

    Do both sides need separate drivers, or is it one driver to run both sides?

    Also, looking at the LED portion of the circuit we'll take the left side for example, I'm confused as to why the right turn signal power is connected to the left turn signal.

    Thank you

    1. Swagatam Post author

      Thanks Chris,

      You won't require two drivers, the first circuit works for both the sides.

      The arrow heads from the LEDs which are assigned with identical numbers will need to be joined together and connected to the relevant diode termination from the IC4017.

      yes you are right, it looks like a drawing mistake, please ignore it, the right/left power must obviously join with the corresponding sections:)

    1. Bill N


      I have read this thread and some of the links. I understand what I want to do is entirely possible but I need some clarification and/or a specific diagram for my challenge.

      I would like the sequential turn signals like Toontje and Chris requested with the turn signals priority over the brake signal AND functioning (dimmer) tail lights when stop or turn signals are NOT in use.

      A link to a corrected, specific diagram would be fine.


      Also I want to use 10 outputs with 3 LEDs on each x2 for each side.
      (30 LEDs + 30LEDs for left and 30LEDs + 30LEDs on the right)

    2. Swagatam Post author

      Hello Bill,

      Please check out the first circuit given in this article. It should suit your application.

      Since you are interested to use all the 10 outputs, T1 disappears from the circuit and all the 10 outputs of the 4017 IC get configured with the SCR/LED network as shown.

      For each three LED string you will need a 150 ohms series resistor for limiting current.

  21. Dan Andrei Andor

    Hi , i wanna use this for turn lights
    1 this circuit is secvential , first led is on until last in on , or only one at 1 time ,
    2 you sad in one comment that max 3 led / 1out , connected in paralel?
    3 what happen if i conect from the flasher unit Taillight

    1. Swagatam Post author

      1) it's sequential but one led at a time, not like a bar graph, rather it's like a dot sequence.
      2)yes three LEDs in series for 12V supply, a couple of more can be added with 16V supply.
      3) sorry, did not get your question??

  22. Brian Walton

    Hi Swagatam
    How could i use this circuit using a feed direct from the flasher unit? I was wondering if it could be modified in the same manner as the sequential bar graph circuit that has the time delay circuit addition to hold the current.
    I want to use the above for the rear indicators only and obviously the feed from the flasher is readily available – Rather than having to run a specific signal wires from the front of the vehicle to the rear just to supply the signals.
    Thanks in advance of any assistance


    1. Swagatam Post author

      Hi Brian,

      you can achieve the same by doing the following quick modifications.

      Increase the base resistor values of the BC547 transistors to around 10K, and connect a 470uF/25V capacitor between the resistor's outer ends (diode junctions) and ground.

      Do this for both rthe BC547 transistors.

      finally you may simply integrate the Right/left diode ends to the readily available outputs from the flasher circuit over the relevant turn signal lamp sockets.

  23. Brian Walton

    Hi Swagatam
    Many thanks for the swift reply to an old thread!
    I will follow up on your suggestion and maybe others will find the mod useful too!
    You've got a fantastic site here for the hobbyist and done some great work and provided a fabulous service for the less able
    Thanks again

  24. Brian Walton

    Hi (again) Swagatam πŸ™‚

    I've been giving the project some further thought. I am wondering what changes might be needed to use single, higher power leds instead of the advised 5mm ganged in threes? So there would be 6 LED's rather than 6*3 5mm

    The reason is that I have combined LED DRL & indicators on the front of my car, so I would like to retain the OEM look & feel at the rear – where I propose to use your excellent circuit design.
    I'm thinking along the lines of the LEDS in the link below.

    They are Osram Opto Diamond DRAGON Series GW Amber LED. They are designed for automotive use in DRL's and indicators.
    They are 2.9v forward voltage and appear to take about 1.4A at typical lumens.

    The LEDs above are not definitive but a suggestion in terms of output and style for my construction needs.

    So my question is can the circuit take or how do I need to modify the circuit to take the extra power these LED's may take.
    For info; from a practicalities point of view, I intend to have a separate driver circuit for each side of the vehicle – it makes installation simpler given i'm going to attach the pulse form the existing indicator relay as discussed previously with you.

    I hope you can advise me (again!) and many thanks for your devotion to the electronics hobbyist on the web.
    Best wishes

    1. Swagatam Post author

      Thanks Brian, I appreciate your interest very much:-)

      Incorporating higher wattage LEDs will need individual transistor buffers across the 6 outputs from the IC, it's actually very easy to implement.

      I'll try to explain the connections verbally, although I am also thinking of updating a suitable diagram for this particular application, I may do it within a couple of days….in the meantime you could try doing the following mods in the above circuit:

      Use TIP122 for the buffer transistors.

      Connect the bases of the 6 transistors to the respective outputs of the IC 4017 via the indicated diodes. Make sure the base have individual series 1k resistors

      The LEDs will need to be attached across the transistor collectors and the positive, the LEDs too must have their own series limiting resistor

      The LED resistors could be calculated using the following formula:

      R = (Us – LEDfwd)/I

      where Us is the supply voltage,

      LEDfwd is the optimum glow voltage of the LED or the forward voltage drop spec.

      I is the optimum current for the LED as specified in its datasheet.

      That's all….. now your circuit is ready and would be capable of handling any type of high watt LEd in the range….

      Best Regards.

  25. Brian Walton

    Hi Swagatam
    I really appreciate your assistance and the fast replies are a treat too!
    I have seen your piece about limiting resistors on another page and thanks for reiterating it.

    I really pleased I've given you some food for thought in enhancing your original design!!
    Im looking forward to seeing the revised diagram ….if and when you have the time that is! I'm on a steep learning curve and think I get your explanation but the proof will be a bonus.

    1. Brian Walton

      Thankyou again Swagatam!
      As a child I used to pull apart old radios to see how they worked. That was a long time ago ( hint pre transistor) Since then I've always been fascinated by the world of PC's and now, with your site, I've had my interest in electronics reignited!

    2. Swagatam Post author

      You are right Brian, I too started in the same manner, and I think most of the hobbyists usually begin by breaking and mending old junks.
      Be assured with my association your electronics passion will not just ignite but light up fiercely:)

  26. Larry

    I have prototyped this circuit on a breadboard and the issue I am having is when I make the connection on the transistor (brake light circuit) I get a single row (3 leds) lit… but no sequencing. But if I touch with my finger on the resister lead coming from pin 11 on the 4060 ic, I get the lights to sequence at a fast rate. (and unable to adjust the speed with the pot). What could be my issue?

    1. Swagatam Post author

      Making the brake connection is not supposed to produce the sequencing effect, rather it's supposed to produce a constant illumination on the LEDs.

      Switching ON the turn signal connection will produce the sequencing effect.

    2. Swagatam Post author

      ..connect an LED from pin16 to ground via 1K resistor of IC 4060, this LED should blink in order to confirm the correct working of the IC 4060, if this does not happen would indicate a malfunctioning IC 4060 stage.

  27. Larry

    Thanks, I meant turn signal circuit. I found that changing the cap from pin 9 of the 4060 ic from 1 uf to .1 uf fixed the problem. I also eliminated the pot and with selecting the correct resistor, I got the sequence to go at the speed I desired.
    I also have the brake light function working perfectly. The only thing I noticed is that there is a slight voltage leakage Bc547 transistors. (in a dark room I can see the faint sequencing/lighting of the leds.)

    1. Swagatam Post author

      OK that's great, however 1uF would also work for producing the same results if P1 is adjusted properly, the leakage could be probably stopped by putting a low value capacitor across base and ground of the BC547 transistors.

  28. stuart jones

    not sure if my comments came through, but this is exactly what we are looking for to make for my son's 73 Mach 1 Mustang. we'll post as we build. thank you for all your help to others – i have learned a lot by reading all the follow up comments.

  29. Wade McBeth

    I am new to doing anything like this, first of all. I did bread board this out also. I am not using switches yet just the positive and negative ports of the bread board with jumper wires. When I have the wire from the 220 Ohm resistor to negative the lights sequence, I had not plugged the right blinker switch wire to the positive side yet either. Am I shorting out somewhere? Also when I do plug the wire into positive on the breadboard and then the wire for brakes it does go solid. Is the To brake switch for the running lights and the to brake light switch run them brighter as in when applying the brakes? Getting closer to getting it running just have a few things to sort out possibly. I am working on this to tinker, but also want to incorporate something like this on my 1966 Mustang. I know there are kits for sale, but whats the fun if you cant try it yourself. πŸ™‚ Kind of like the setup from website.
    Thank you and have been reading through all questions and comments as well

    1. Swagatam Post author

      Hi, the 220 ohm switch is ganged with the another switch indicated just beside…so both these switches need to be switched ON simultaneously for switching ON all the LEDs together (dimmed) and with the sequencing effect cancelled.

      In order to implement the brake light illumination the vertical diodes connected at the bases of the BC547 transistor also need to be connected the positive line simultaneously along with the bottom diode end indicated as "to brake switch", I think you might have missed it…

  30. kikira

    Good morning sir,
    I have done with this ckt last night. Just a prob. there…Am I need two diodes;one for ic out put and another with led pannel. Please help…..
    With regards ,
    K. Kausik

    1. Swagatam Post author

      Kaushik, yes that's right, it is clearly shown in the diagram, the LED panel diodes go to the brake light switch while the arrow heads show the points which needs to be connected with the 4060 diodes.

  31. Wade McBeth

    Not sure what is going on, but when I use the 1uF/25v at C1 on the IC4060 nothing happens. When I use a 103 capacitor all works fine. Any suggestions as to what is going on? I am a novice at this and I thank you for your reply.

    1. Swagatam Post author

      that's very strange….by saying "nothing happens" do you mean to say that the LEDs don't "run"??

      under any case that cannot happen, because changing the 100k pot setting should adjust things as per the C1 value and help to achieve the intended response across the LEDs ….please check all the pinout connections of the IC with the relevant components.

  32. Wade McBeth

    The LED's will at times come on and stay on, at other times will not come on at all.
    No sequencing at all. Even when connecting an LED to pin 15 as you had suggested in an earlier post, the LED does not flash stays solid. Is there a certain way I need to connect the 100k pot? I have it all laid out on a breadboard, the pot has three pinouts with a small setscrew on top to adjust. I have connected it various ways and there is nothing happening when I do any adjustments to the 100k pot. Yes, I will double check all connections as well. Thank you Swagatam.

  33. Tomas Ortiz-Potter

    Alright, I'm most definitely determined to make this and apply it to my car, BUT im having trouble with the schematics. Can you please, for me and everyone else wanting to make this, make a new schematic that incorporates them both together. In the first schematic where can you apply a POT? im assuming PIN 11 of the IC4060. Also are the diodes(1n4007) running from 4017 in the first schematic the same ones appearing in the 2nd schematic that connect to the LED's? If the 1st schematic is the only driving circuit how is there a left and right side of LED's in your 2nd schematic?
    I would really appreciate if you could make another digram/circuit/schematic all in one with just a tad more detail, PLEASE you would be a hero.

    1. Swagatam Post author

      I have the updated the design as per your request.

      P1 is speed timing pot.

      The left and the right turn signal switches decide which set LEDs need to "run" as per the user preference.

    1. Tomas Ortiz-Potter

      So I recieved all my parts and built this circuit on a breadboard…before finalizing this circuit on pcb board, how do I test this circuit without hooking this up to my cars positive+ground and brake switch? I don't want to go splicing wires in my car unless I know this is a fully functional circuit. I'm assuming I would have to hook this up to a power supply(12v)….but what could I use to imitate a brake switch signal and both left & right signal? Also to help others and myself, understand your diagram better; are those LED'S in series or parallel?

    2. Swagatam Post author

      obviously you will need a 12V power supply to test the circuit on your work bench.

      connect the 12v supply to the circuit, then make all the indicated "brake switch" wire ends common (join them together) and manually connect the joint to the positive line…this will simulate the brake application and hopefully illuminate all the LEDs (if you have done everything correctly.)

      Do the same with the L/R wire ends…connect these individually to the positive line for implementing the relevant L/R chasing LED effect.

      LED are in series on each channel

  34. Reeko

    Sir, can you explain a bit on S1 switch, Battery Positive & Dim Tail Light. where do you install this switch inside the car. Is it necessary to have this switch. Thank you for reply.

    1. Swagatam Post author

      Reeko, S1 is optional and may be included only if you want the dimmed LED feature.

      S1 switches are GANGED together, that is both are joined and are switched ON in a combined way.

      Please click on the diagram to enlarge and just wire the parameters exactly as shown.

  35. Reeko

    Sir I have tested this circuit on a bread board, the BC547 blow up, I tested 3 times…what do you think could be the cause? I have check every wiring. The 7812 Vin and Vout, Vin is from the diode to +12V correct?

    1. Swagatam Post author

      Reeko, the BC547 transistors can blow up due to any of the following four reasons:

      base 1K not included.
      collector shorted to the positive line
      pins wrongly connected
      duplicate quality B547 used

  36. Dr Anupam Das

    as commented by Wade McBeth the leds becomes solid without sequencing and there is no blinking signal at pin 15 of IC 4060 , only in pin 7 the led blinks and rest pins show steady led, the touching of PIN 11 of IC 4060 signifies something as pin 7 outputs blinking led when touching pin 11. please clarify the point

  37. Dr Anupam Das

    as per as diagram one end of 100k resistor connected to pin 10 of ic4060 should be connected to one outer end of pot and the other outer end of pot should be connected to the another end of 2.2M resistor connected to pin 11 where the middle point of potentio meter also gets connected . Is it correct ? or one outer end of potentio-meter can be eliminated and only the middle point should be connected to another end of 2.2M resistor along with other pin of capacitor connected to PIN 9?

    please refer to this image
    and correct me whichever should work,image 1 with RED circle and image 2 with green circle.

    1. Swagatam Post author

      The middle is the most important pin of the pot, it must shorted with any of the outer pins, that will do the job.

      to be precise only the middle and any one of the outer leads needs to be used, the other outer can be left unused….just as indicated in your no.2 diagram.

      both the diagrams are correct.

  38. Dr Anupam Das

    thanks for support. whats the wrong with this circuit ?? please check image
    pin 9 10 11 of 4060 contains the exact resistors and capacitor (as 1uf didnt work i have tried 0.1 and .01 ) pin 8 and 12 ground and pin 16 Vcc .. so that PIN 15 should get blink signal.

    i could not make it to work even after trying 3 ICs with all different components , i am 100% sure all components are working and wiring as per as your circuit . as this IC is very reliable what can be the cause ?? the 4017 part is working.

    1. Swagatam Post author

      A 1uF capacitor will definitely work, in fact any capacitor will work.

      0.1uF or 0.01uF will make the oscillations so fast at pin#15 that the connected LEd will appear glowing constantly.

      did you check the oscillations at pin#3, 2, 1 etc using an LED if all these pinouts are not responding to P1 adjustments, then there may be certainly something not right in your design, make sure the IC is from a reputed brand, having a prefix such as CD, ST, TI etc. before the number 4060

      If you are having problems with 4060 IC you can simply replace it with a IC555 circuit.

  39. Anonymous

    Touching pin 11 with a forcep starts blinking led at pin 15 however for a while only. Some users also commeneted that touching pin 11 starts blinking . Why it happens? Morever 555 ic gives constant chasing not a sequence

  40. Dr Anupam Das

    IC is CD, i have tested with two more same CD4060 , same result at pin 3 constant led and also in pin 15 constant led and no response to P1 , capacitor at 1 uF, why touching the pin 11 starts led to blink ? IC555 circuit can i get sequential

    1. Swagatam Post author

      Pin#11 is the oscillator input of the IC, may be this in not properly connected with the 2m2 resistor in your PCB, you can check it.

      Any blinking or oscillating input at pin#14 of the IC 4017 will always produce a sequencing logic across its output pins, it does not matter whether it's from 4060 or from 555 IC or from any other source.

      Normally a good IC may be identified with a visible and hard etched print on it.

      the supply voltage should be a good DC at above 5V

  41. Dr Anupam Das

    i am able to do the sequencing using 555 instead of 4060 . i have used all 10 channels with piranha led 4 nos in each series with Bipolar transistor as power. applying 12 volt to the board shows a smooth sequencing . how to connect this to TURN signal ? i dnt want any brake or optional light , just i need that whenever i turn right or left the led should show sequence irrespective of any other switches like brake or parking as i have separated them with individual led array(also two boards for each left and right indicator). The turn signal gives 12 volt with a relay in central power system of car . if i put this signal as supply to the led board , the sequence is incomplete as it cuts the 12 volt synchronized to relay tik tik.? Should i bypass this relay system?? Or putting the board in constant 12 volt supply and using the turn signal to make it active only whenever the turn switch is on??
    will the led shows the sequencing uninterruptedly if i use TIP122 at led array and powering this tip122(at base) with turn signal? i mean to say as the turn signal contains voltage with on and off pattern will this signal at TIP122 base shows the same effect as if the board is powered directly and without the TIP122 signaling section

    1. Swagatam Post author

      you can connect the board directly with the 12V from the turn signal switch, the turn signal flasher can be removed it won't be required here. So whenever any of the turn signal switches are switched ON the relevant LEDs will start sequencing and continue doing so as long as the switch is ON.

  42. dr anupam das

    hi swagatam , can i use npn 2n2222 without a base resistor directly to pin outputs of cd4017 for getting collector correct ?

  43. Anupam das

    The above circuit.. instead of bc 547 i am using 2n2222.. piranha led current is 80ma and ic 4017 output current is 5ma. Ic output is connected to base of 2n2222.

  44. anon

    The BC547's have a max continuous collector current of 100mA, does this mean that it can only be used with LEDs drawing less than 100mA each? Thanks!


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