Tips
It is pretty simple to wind
a transformer with a toroid core. You can usually find a suitable core in an old compact fluorescent bulb base. I have also heard of people winding wire onto a nail as a substitute, or using two commercially available coils (they look similar to resistors) side by side. You can find coils and cores in old computer power supplies as well.
Notes
The prototype of
solar cat eye road stud is suitable for lab evaluation/demonstration purposes only. The real practical solar cat eye road stud should be fixed to the road in a conventional way (glued or drilled). A solar cat eye road stud must be highly visible in all lighting and roadway conditions.To achieve the maximum possible driver acceptability it may necessary to put all the circuitry in the same housing as that now used for conventional reflector studs. It is recommended to use materials like Die Cast Aluminium and High Strength Polycarbonate for making a suitable enclosures.
Lab report
(1)Current consumption in idle state (day time – Solar panel working/LEDs OFF ): near 1 mA /from 1.2V battery.
(2)Current consumption in active state (night time – Solar panel not working/LEDs ON ): near 30 mA /from 1.2V battery.