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 are not available but a powerful flashing light are yet necessary.
Circuit Diagram:
Parts:
- R1 = 6.8K
- R2 = 220K
- R3 = 22K
- C1 = 100uF-25V
- C2 = 10u-25V
- D1 = 1N4002
- Q1 = BC557
- Q2 = IRF530
- LP1 = 12V-21W Car Filament Bulb (See Notes)
- SW1 = SPST Switch (3 Amp minimum)
- Flashing frequency can be varied within a limited range by changing C1 value.
- As high dc currents are involved, please use suitably sized cables for battery and bulb(s) connections.