I want to control a circulation pump. I'd like it to have 3 settings:
Off
On
Auto
the problem is with the "auto" function, because the input could be from two different circuits ('too hot, turn on!' or a 'too cold, turn on').
A two-stage temperature controller would be sending the signal, it has a high range and a low range, and both a heater and chiller would be attached to control a water bath at a fairly precise temperature.
I thought about a 4 way - off, on, auto cool, auto heat ---however I may not know which circuit is engaged, and I don't want to manually switch the pump back and forth.
so, to prevent energizing the wrong circuit, I'm thinking a diode on each line feeding the input leg of the switch would prevent the heater energizer from energizing the cooler and vice versa.
pump's current draw is under 10 watts, 120V
would this work, and what size diodes?
thanks a million!
Off
On
Auto
the problem is with the "auto" function, because the input could be from two different circuits ('too hot, turn on!' or a 'too cold, turn on').
A two-stage temperature controller would be sending the signal, it has a high range and a low range, and both a heater and chiller would be attached to control a water bath at a fairly precise temperature.
I thought about a 4 way - off, on, auto cool, auto heat ---however I may not know which circuit is engaged, and I don't want to manually switch the pump back and forth.
so, to prevent energizing the wrong circuit, I'm thinking a diode on each line feeding the input leg of the switch would prevent the heater energizer from energizing the cooler and vice versa.
pump's current draw is under 10 watts, 120V
would this work, and what size diodes?
thanks a million!
Attachments
-
8.8 KB Views: 29
Last edited: