On this enterprise, I will current you the best way to design a simple Bike Turning Signal Circuit using 555 Timer IC, couple of LEDs and a few completely different merely accessible components.


Flip Indicator Lights additionally known as Directional Indicators (formally) or Blinkers, Flashers (informally), are an necessary half all vehicles whether or not or not a motorcycle or a vehicle. They inform completely different road clients our intent to indicate left or correct. There are a selection of guidelines and necessities that producers ought to modify to whereas designing and integrating Flip Lights on to a automotive.

Bike Turning Alerts are used to level the intent of left flip or correct flip to completely different clients of the road. Have you ever ever ever tried to design bike turning indicators? This textual content explains you the best way to design these bike turning indicators.

Bike Turning Signal Circuit Principle

The goal of this circuit is to level left or correct flip for bike/automotive. The precept a part of this circuit is the infamous 555 Timer IC. Proper right here, this 555 timer acts as an Astable multi vibrator. It generates the guts beat signal with variable width. Using this variable width of the guts beat, we are going to set fully completely different time delays for the LEDs (ON and OFF for LEDs).

The circuit consists of two very important resistors (100KΩ and 470KΩ), which might be linked to 555 timer and these are used to set the time delay for LEDs. The output of the 555 Timer IC is given to each LEFT indicator LED or the RIGHT Indicator LED using a Slide Change. 

1n4148 signal diode is linked in reverse bias on the output to maintain up fastened current on the output. BC547 (NPN) Transistor switches the LED’s ON and OFF primarily based totally on the underside currents. 330 ohm resistors are used to drop the voltage in some other case LEDs might get damaged. Proper right here we are going to fluctuate the time width of output pulse by varied the resistance or capacitance price.

Bike Turning Signal Circuit Diagram

Bike Turning Signal Circuit Circuit Diagram

Circuit Elements

  • Resistor 180Ω
  • Resistor 100KΩ
  • Resistor 470KΩ
  • Capacitor 1µF
  • 555 Timer IC
  • LEDs – 2
  • Diodes (1N4007) – 2
  • SPDT Slide Change
  • 9V Battery
  • Connecting Wires
  • Breadboard

Bike Turning Signal Indicator Circuit Design

On this circuit, the 555 timer produces pulse signal with variable width. The center beat width is numerous by varied resistance or capacitance price (100KΩ, 470KΩ or 1µF). Pins 2 and 6 are shorted to allow triggering after every timing cycle.

Fourth pin is reset, it is shorted with VCC (8th pin) to stay away from sudden resets. 7th pin is discharging pin, it is linked to 6th pin by the use of a 470KΩ resistor. The beneath decide explains you the operation of 555 timer. On this circuit capacitor C charges by the use of resistors RA and RB. Now on account of inside op-amps, capacitor C discharges by the use of resistor RB. 555 timer internally encompass two operational amplifiers, one D flip flop and one NPN transistor.

555 Timer in Astable Mode

555 Timer in Astable Mode

Inside the above circuit, the guts beat is generated on the threerd pin of the 555 timer. By varied the values of RA, RB or C, we are going to fluctuate the guts beat width. The entire time interval of the guts beat is given as

T = THIGH + TLOW = 0.693 (RA+ 2RB) C

 Frequency of the guts beat is given as

f = 1/T = 1.44/ (RA+ 2RB)C

proportion of obligation cycle is given as

% obligation cycle, D = t/ T * 100 = (RA + RB) / (RA + 2RB) * 100

The obtained pulse from the 555 timer is utilized to the LEDs by the use of the slide change to make the LEDs ON and OFF with some delay. Proper right here the working voltage of LEDs is spherical 2 to 3v nonetheless from battery, we get 9V present. So, we have now to drop the remaining voltage. To drop this voltage, we’re using resistors in sequence with LEDs.

Bike Turning Signal Circuit Image 2

The best way to Perform the Circuit?

  • Initially feed 9V power present to the circuit.
  • Slide the change to the Left place and you could observe the LEFT Indicator LED will start to Blink with some delay.
  • Within the occasion you slide the change to Correct Place, the RIGHT Indicator LED will Blink.
  • Within the occasion you slide the change to coronary heart, every the LEDs could be OFF
  • In case you want, set the fully completely different time delays for LEDs, then fluctuate the resistance or capacitance price.
  • Now you might even see the change in time delay.
  • By varied the capacitance price moreover you might even see the in time delay of LEDs.

NOTE: Since this is usually a demonstration, I’ve used only one LED per channel (LEFT and RIGHT). Nevertheless for those who want to mix plenty of LEDs per channel, you’ll be able to do this with the help of a Transistor on each channel and satisfactory power present.

Bike Turning Signal Circuit Image 3

Features of Bike Turning Signal Indicator Circuit



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