Nice.
We'll have to assume that the Pelt PSU is seperate from the PC's PSU.
As a power source, the PC's PSU has a +5 line that's always on (+5 standby), as long as the switch is on, so we can tap into that to power this circuit.
So the objectives are:
1) Turns peltier PSU, pump, and fans on and off with the PC so that there is no danger of running the pelt without pump.
2) Shutdown if temperatures exceed a certain point (the cold plate seems a logical spot to measure to me).
3) Shutdown of system in the absence of flow
4) A delay for PC boot until the cold plate is cold
#1
We might not have enough power to drive a DC fan off of that standby line, so it'd have to be driven from the Pelt's PSU, or be left off until that coldplate temp (#4) is good. The pump can still turn on though (if it's an AC pump).
#2
We can either use a thermal switch (easy, bulky?), or figure out how to setup temp probes. I prefer the temp probe, it seems more interesting.
#3
Let's try to avoid the OC flow sensor, the one with the cork plug
. It shouldn't be a big flow restriction, whatever we come up with.
#4
If we're going to build a temp probe, that's the way we should do #2 as well. Do we want to tap into the "Power_OK" line from the PSU, or just cut off the "Power_ON" line? Could we add a solution, alongside, to allow for a soft shutdown? that would mean setting two temp levels, one for a soft shutdown, one for a hard shutdown, unless we just implement a delay.