Today I ordered about 20 different types of relays. I’ve got to find the one we’re going to use since we need to know the size and voltage and resistance, etc. The big problem is that the one I want is about $5 in bulk which means about $160 in relay cost alone for one bit of the ALU which is a lot of money. The ALU isn’t fully designed yet since I need to figure out the control and I/O board still but I’m guessing that total we’re going to need about 200 or so relays. So my target price per relay is more like $1-$2.
Another relay requirement is that they make a good amount of noise since this is the whole reason for this project (to make a cool clicking computer). Also we want to mount them on a PC board without needing to add sockets for each one. The sockets, while cool and useful, would add even more cost. I’d like to also keep the voltage down to 5V or maybe 12V at most.
When I get the relays and start to play with them I’ll update you all.