I built a counter circuit that I want to count down from :30 to :00.
It is composed entirely of 4000 series logic. I'm using two 4510 chips and two 4511 chips.
I built an astable that works but not when connected to the circuit.
These counting circuits work when on the breadboard but not when soldered together.
I use wire lengths to connect everything together. I just bought new chips and installed them.
When I turn it on random digits come on the display each time I connect and disconnect power.
The preset input which I have tied to a 10k pulldown resistor doesn't preset the display when I take it high.
I'm thoroughly confused and would welcome any advice.
It is composed entirely of 4000 series logic. I'm using two 4510 chips and two 4511 chips.
I built an astable that works but not when connected to the circuit.
These counting circuits work when on the breadboard but not when soldered together.
I use wire lengths to connect everything together. I just bought new chips and installed them.
When I turn it on random digits come on the display each time I connect and disconnect power.
The preset input which I have tied to a 10k pulldown resistor doesn't preset the display when I take it high.
I'm thoroughly confused and would welcome any advice.