A very simple 555 timer circuit Warning lights for bicycle with automatic disconnection can be designed using this circuit. This 555 timer circuit Warning lights for bicycle circuit will turn off warning lights of bicycle after about 3 minutes.
The battery is charged in the same time while lights are "connected". When stopping at a traffic light, the voltage supplied by the dynamo is void. Trigger input of timer IC1 (pin 2) receives a negative pulse relay attracts at which point lighting is provided with voltage from the battery through the relay until the voltage at pin 6 reaches the internal reference voltage of the integrated circuit. when the battery relay triggers and separate lighting and the whole assembly. This time is set by R2 and C2 at about 3 minutes .