Reducing current draw on using CMOS logic gates

Other Hardware General Electronics
8

Grumpy_Mike:
If the metal is getting hot then there is a bad connection and a lot of current. If you are lucky you just shorted the power supply, if not you blew the chips.

i guess i was lucky, perhaps not totally shorted, but certainly drawing unnecessary current.

adwsystems:
Where did the LEDs come from?

Then you have a high current draw on you power rails or a resistive connection. Dirty connections introduce resistance. Resistance causes a voltage drop. A voltage drop is power dissipated. Power is heat.

the LEDs are to indicate the SUM from the Adder.

i also forgot to mention; to complete the full-adder, i used a "manual" OR gate, but tried two versions, one using transistors, with 680 Ohm resistors, and another "simpler" one with just diodes.

i am thinking it's this second OR gate that might be drawing unnecessary current ?

here's the circuit;