Dishwashers are rare over here on the wrong end of the planet. I've looked into solenoid valves but they are seldom in my price bracket. Another thing is that having something like that would require the water level in the secondary tank to be higher than that in the primary tank, at which point one might as well just use a simple connecting tube to keep both water levels equal.
I don't want to do this for two reasons:
1) A smaller volume of water cools faster
2) Having holes below the water line makes the system more prone to leakage. Aside from my questionable ability with a drill, a line might also get disconnected by accident, or the tank get filled without the line connected. I know the above all can be solved by paying a little attention, but as we all know shit happens, and my philosophy has always been to give it as little opportunity as possible.
Thus I envision an electronic system that responds to two water levels. If water is below both sensed levels, a pump is turned on in the secondary tank, and pumps water into the primary tank until the full level is reached.
What I need help in is figuring out how to actually build such a circuit. I am thinking that it will involve some kind of very basic logic circuit with some kind of memory. The logic table would be something like: (let the two levels be EMPTY and FULL)
EMPTY FULL PUMP
0 0 Turn On
0 1 Hold State (theoretical situation, in practice this would never happen for obvious reasons)
1 0 Hold State
1 1 Turn OFF
Can anybody suggest me what I need to look into? Preferably something solid state except for the pump relay, and operating directly from a 12VDC source.
Thanks!