Learning Electronics

Learning Electronics

Learn to build electronic circuits

Led or Lamp Flasher Circuit

Ideal to operate 3 to 24V DC existing on-circuit lamps

This circuit was designed to provide that continuous light lamps already wired into a circuit, become flashing. Simply insert the circuit between existing lamp and negative supply. Especially suited for car or panel pilot lights, this device can drive lamps up to 10W.

Circuit diagram:

Led or Lamp Flasher Circuit Diagram


R1 = 6.8K
R2 = 270K
R3 = 220K
D1 = 1N4002
C1 = 220uF-25V
C2 = 10uF-25V
Q1 = BC557
Q2 = BD139
B1 = Any type in the range 3-24V
B1 = Suited to the lamp adopted
LP1 = Filament Lamp 10W-3V to 24V
SW1 = On-Off Switch


Source: Red Free Circuit Design