[AI2V]

TA- I think you would find that an incandescent bulb would require much more current than the circuit would allow. That's the reason that I chose the 5mm LED's; even the 10mm LED's drew too much current to be usable.

A lamp or larger LED could be used if someone wants to do a design including an active circuit with a FET or transistor; that wouldn't be very difficult but would require many more parts and a low voltage supply.