Power Flasher

Suitable for alerting purposes

Drives 12V Car bulbs

Circuit diagram:

Power Flasher


R1______________6K8  1/4W Resistor
R2____________220K   1/4W Resistor
R3_____________22K   1/4W Resistor

C1____________100µF   25V Electrolytic Capacitor
C2_____________10µF   25V Electrolytic Capacitor

D1___________1N4002  100V 1A Diode

Q1____________BC557   45V 100mA PNP Transistor
Q2___________IRF530  100V 14A N-Channel Hexfet

LP1___________One 12V 21W Car Filament Bulb or two wired in parallel (See Notes)

SW1___________SPST Switch (3 Amp minimum)


Derived from the Two-wire Lamp Flasher design, hosted on RED Free Circuit Designs since 1999, this astonishingly simple circuit allows one or two powerful 12V 21W car bulbs to be driven in flashing mode by means of a power MosFet.
Devices of this kind are particularly suited for road, traffic and yard alerts and in all cases where mains supply is not available but a powerful flashing light is yet necessary.