Timer driven wig-wag flasher

First switch powers up the light circuit. Second switch engages flashing circuits. Flasher is driven by a 555 timer IC and each relay is driven by a transistor which is being fed by the timer output. One relay has a second transistor for the inverter effect of the timer so the lights will flash alternately. This circuit simulates the flashing ditch lights on a railroad locomotive, where the flashing circuit is activated automatically by the horn valve and/or warning bell valve. The LEDs simulate a 300 watt incandescent bulb and the RC circuit gives the appearance that the light is dimming as intended.

published 8 years ago