Two-wire Lamp Flasher

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

LED operation is also possible

Circuit diagram:

Lamp Flasher


R1______________6K8  1/4W Resistor
R2____________270K   1/4W Resistor
R3_____________22K   1/4W Resistor

C1____________220µF   25V Electrolytic Capacitor
C2_____________10µF   25V Electrolytic Capacitor

D1___________1N4002  100V 1A Diode

Q1____________BC557   45V 100mA PNP Transistor
Q2____________BD139   80V 1.5A NPN Transistor

LP1___________Existing filament Lamp: any type in the range 3-24V 10W max.

SW1___________Existing On-Off switch

B1____________Existing V DC source: any type in the range 3-24V
                                    suited to the lamp adopted

Device purpose:

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.