This circuit was found in Electronics Handbook, Vol XIII 1993 and consists of a simple direction indicator or arrow to bicycles. The circuit is triggered when pressing PB1 and PB2 after S1 being closed. The LEDs are common and the circuit is powered by four small batteries. The components are given in the list below:
Q1 - BC548 or 2N2222 - Transistor
R1, R2 - 100k ohm 1/8 x W
R3 - 1 k ohm
R4, R5, R7, R8 - W 1 x 100 Ω
R6 - 10 K Ω
C1 10 µF electrolytic V x 12
L1, L2, L3, L4 - red LED high-brightness
PB1, PB2- pressure switches NA
S1 - SPST switch
IC1- 555 - Integrated circuit
