Solar powered Road Studs are used for road safety, traffic guidance and to mark traffic hazards. The Bright flashing LEDs give drivers enough time to react adequately in case of emergency. This kind of LED blinkers are used in Traffic dividers and Pedestrian crossings in Highways. Here is a Solar based LED blinker that uses an LDR to activates the light at sunset or in foggy weather.
A 6 volt 150 mA solar panel is used in the circuit to charge the 6 V rechargeable battery during day time. CD 4060 is used to drive the LEDs. CD4060 is the binary counter IC with 10 outputs, of these only the first output is used here. Capacitor C2 and resistor R2 determines the frequency of oscillation and with the given values, the LEDs blink very fast.
During day time Battery charges via D1. The reset pin 12 of IC1 is connected to a potential divider comprising LDR and R1. So during daytime, LDR conducts and keeps the reset pin of IC1 high to prevent its oscillations. When the day light ceases, reset pin of IC1 goes to ground potential and the IC starts oscillating. Transistor T1 then turns on / off alternately and the LEDs blink.
Use 6 Volt rechargeable battery pack used in portable devices. You can also procure the battery from China make LED emergency lamps.