Unless it's a purely digital circuit (and possibly even
then) the different voltage level will definitely affect
its operation. Find the proper chip.

yhan wrote:
good day, let me ask more question please.

I have here 7805 regulator ready for use. I just dont understand if a
12 volt circuit design can be operated on 5 volts. Let me enlighten
with this thing. Can it be compatible? Is there no operating
differences or malfunction of the circuit because the circuit will
operate with lower voltage supply and that might affect the operation
because it doesn't go with the circuit design? If it is still works,
i'll be glad coz i will not bother to find 74c14 which is not available
in my place.

tnx again,

ian