Flashing LED unit

john November 15, 2011 29 Comments

The circuit given here is designed as an LED flasher which produces a rotating effect when the LEDs are arranged properly. The circuit has very low current consumption and can be operated from even 3V button cells.

The IC 1 (CMOS NE555) is wired as an astable multivibrator wired at a duty cycle of 50% and 4Hz frequency and drives LEDs D1 to D6.The second IC, IC2 (CMOS NE555) is working as a trigger pulse inverter and drives LEDs D7 to D12.The circuit is arranged such that the ICs sink the current consumed by the LEDs. At low operating voltages like 3V, the CMOS NE 555 performs better when arranged in sinking mode rather than in sourcing mode. The LED D13 remains permanently ON.

Circuit diagram with Parts list.

LED Arrangement.



  • Arrange the circuit on a good quality PCB.
  • The circuit can be powered from a 3V battery.
  • The ICs must be fixed on holders.
  • The switch S1 can be a slider switch.
  • To get a rotating effect arrange the LEDs on a plastic sheet as shown as in the figure.
  • June 23, 2015

    This circuit has possibilities for what I am trying to do. Can it be modified to run 3 banks of leds at 12v?

  • Masroor Mastoi
    November 5, 2014

    whic ic can i use in plase of ne555, because it is not available in my regioun

  • May 10, 2014

    sir mai led arrange karke 12v dc se chalana chahata hun kaise arrange karoon

  • Virender
    March 10, 2014

    Dear sir, i want to make blinking led circuit using chip 555 with ldr so the circuit can be turn off in daylight. Can you please provide such schematic. Thanks in adv.

  • Honey
    October 12, 2013

    Can ANy one tell please the ratings of capacitor used………..

  • Al Amir Sultan
    July 21, 2013

    I just want 2 ask, i try this project at strip board.
    But just LED D1-D6 blinking only.
    D7-D12 not function. I check probably for wire is right.
    So what can i do??


  • July 19, 2013

    A really nice post sir . I been looking for electronic mini projects . This one seems good to me . I will try to construct it .

  • m.asim hashmi
    May 27, 2013

    i want to learn and i think that i can learn from this web,

  • dinesh gupta
    March 30, 2013

    sir, iam new in building electronic project. i want to make large board like 11*13 size. i want to make govt. iti on board using flashing led circuit . can i use this circuit or not?if not , acn u tell me circuit can be used?

  • kimxerg
    December 13, 2012

    hello, we have a school project and we would like to make this one , do you have a PCB design sir? and can we use different color of LED’s?
    thank you so much…
    God Bless

  • alex
    October 11, 2012

    i just ask if what voltage are those capacitors?

  • Seetharaman
    June 16, 2012

    Hi Din if you want to use 12volt supply you have to modify the circuit. you have to increase the current limitting resistances of all 13 LEDs to 1K ohm 1/4 watt.

  • Din
    June 14, 2012

    Hi, I’m currently doing school project regarding LED flasher,
    By referring to diagram, can I use power supply 12VDC?

  • Dennis
    November 25, 2011

    Electronics student from nigeria,this circuit is fine, thanks so much.Sir, i want to know if there would be any damage if more than one LED is used in place of one say D1 or D2. Again i need a LED circuit that shows a name blinking line by line one after the other in orderly manner just like on screen.I will be so happy if i see one

    • shahida irshad
      January 9, 2013

      Assalamo Alikum.. sir i want the circuit for dancing Leds that using blinking.. Regularly or after some times.. please reply as soon as possible .. thank you so much

  • RICK
    November 12, 2011


  • RICK
    November 12, 2011

    THIS Circuit Is GOODS!

  • RICK
    November 12, 2011

    THIS Circuit has infinite Possibilities!!!

  • deepak
    August 1, 2011

    Hello sir, i want to make mains operated 2 chains blinking led circuit with 25 leds in each chain and 2 chains should flashes alternately. Can you suggest me the circuit?
    plz reply!

  • Seetharaman
    March 13, 2011

    Hi Anthony As view from the top, (where IC type is printed) there is a dot shown against one of the end pins. this dot indicates pin no 1 from there the number should be counted in the anticlockwise direction. please go through the following site.

  • March 11, 2011

    I’m new in electronic circuits, and i like to leran how
    to make Running Led Lights, Blinking Lights. but my problem
    isthat i don’t understand for example the IC1 NE 555 pins numbers, i mean i don’t know which one is number 1, 2, 8 ext.

    please if you can help me I will be thankful.


  • Rakesh
    October 18, 2010

    I’ve a question. Cannot the first IC(The upper one)take all the load? I mean, if the circuit can be made with only one 555 timer.

  • aswin
    March 13, 2010

    wow! this circiut is nice. it’s working.

  • Benet Gaytos
    February 23, 2010

    This is great I am looking for a multi mode LED light circuit This one is great but hoping for a multi-mode LED light

  • October 23, 2009

    dear sir,
    i am danish from pakistan, i make here, led police light,. and i want to use ic, in pcb for flashing 14pin,. ic,. i need, 3/4 diffrient mode change flashing mode, plz let me ic number, which ic i use in our pcb thanks. i use 60 led in our pcb board, and i need, 3/4 diffrient flashing mode, plz give me ic number thanks. regards.

  • Farasat
    July 10, 2009

    please tell me the all capacitors volt and which type of led should i use in leds white leds or colourful leds thanks.

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