The Simple and useful bicycle direction indicator circuit is given, the Astable multivibrator is designed with IC 555 and the output is given to single pole dual through switch (spdt), the output fed into LEDs.
Hence it will glow frequently to indicate the turning direction (use yellow or orange colour LEDs), in this circuit you can choose Resistor R2 as a variable resistor to vary the speed of light.
|2.||Transistor SL 100||2|
|3.||LED (yellow or orange colour)||16|
|6.||Capacitor 33µF/16v ,0.1 µF||each 1|