This project is installed in a car, to modify brake light flasher circuit. 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 flash when a brake is touched only.
In the circuit is modification flashing to the brake light. The working start with the 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.
The transistor-Q1 is a trigger to IC2 and also results in pin 3 of the IC2 reverse stage, by getting a 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 feeds 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. So, be careful about the polarity of the electrolytic capacitors and Diodes correctly, Pin of the IC is not an error. And pin of transistors (BC337 and BD139) you can look at the image below.
Resistors size ¼W +5%
R1, R2: 10K
C1: 3.3uF 25V, Electrolyte
C2: 1uF 25V, Electrolyte
C3: 0.1uF 50V, Polyester
Q1: BC337, 50V 800mA NPN Transistor
Q2: BD139, SM3180
IC1: CD4024, 7-Stage Ripple-Carry Binary Counter
IC2: LM7555, CMOS Timer
Universal PCB Board
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