Hi,
I'm new on this site and I'm an absolute beginner in electronics.
My target is to build an adder - inspired by this Ben Eater video:
I use an XOR chip from TI: SN74HC86N, 5V on pin 14 and Ground on pin 7.
The problem is that I get an output on pin3 despite no input on pin 1 or 2.
I measure just under 1V on pin 1 and 2 - I was expecting 0 V, and I don't understand why pin 1 and 2 are charged.
I have tried installing a pull-down resistor, 10k, and it worked in a small test installation.
The final installation, however needs two XOR chips with a total of 16 inputs - it's going to be a lot of pull-downs and quite messy.
And most importantly: The samples I've seen on the internet don't need this (ok, Ben uses a chip from Fairchild, but they should be the same..?)
Any comments or input?
I'm new on this site and I'm an absolute beginner in electronics.
My target is to build an adder - inspired by this Ben Eater video:
I use an XOR chip from TI: SN74HC86N, 5V on pin 14 and Ground on pin 7.
The problem is that I get an output on pin3 despite no input on pin 1 or 2.
I measure just under 1V on pin 1 and 2 - I was expecting 0 V, and I don't understand why pin 1 and 2 are charged.
I have tried installing a pull-down resistor, 10k, and it worked in a small test installation.
The final installation, however needs two XOR chips with a total of 16 inputs - it's going to be a lot of pull-downs and quite messy.
And most importantly: The samples I've seen on the internet don't need this (ok, Ben uses a chip from Fairchild, but they should be the same..?)
Any comments or input?