This project is installed in a car, to modify a brake light into flash. Using a small number of pieces of equipment, so it is easy to build, consists of CMOS IC and power transistors etc.
The rear brake light is warning lights to the behind car. Add Caution while tracking. This flashing brake light to sensitive drivers who tracking behind. Can be visible as far add to secure than a plain brake light. Which it will flashing when brake is touched only.
In Figure 1 is modification flashing to the brake light. The working start with power to circuit or touch that brake. The timer-IC2 is driver current to transistors feed a clock signal pulse out to pin 3 go to pin1 of IC1, count amount of pulse and will stop counting when full 8 pulses. By pin 2 of IC1 will reset itself.
Figure 1 The circuit to modified the brake light into flash.
The transistor-Q1 is trigger to IC2 and also results pin 3 of IC2 reverse stage, by get voltage drop across R3 cause have output voltage at pin 7 of IC2 cause Q2 receive forward bias to drive current cause the brake lamp glow up.
The flashing of bake light while touch bake Hold it, Will flash continuously per set around 6 times per second. Which defines by the R3 and value C3. The distance of each series is determined by the C2 and R1. The voltage that feed to the circuit can use DC 12 volts of Car. The capacitors-C1 is a filter to smooth the currents. The transistors-Q2 may use any number SM3180.
How to build it.
We can assemble all components on the universal PCB board. The wiring for circuit wiring and various components can view of the example in Figure 2. So be careful for the polarity of the electrolytic capacitors and Diodes correctly, Pin of the IC is not an error.
Figure 2 The components layout of this project.
Resistors size ¼W +5%
Q1___________BC337___50V 800mA NPN Transistor
IC1__________CD4024___7-Stage Ripple Carry Binary Counter
Universal PCB Board__________1 pcs.