Howdy everybody!
I was kind of thinking this might be thought of as automation as in automating it to be as efficient as possible to enjoy some luxury on our renewable energy system.
I am hauling my fridge from the states to the Philippines because you just can’t buy this kind of fridge over there. You get used to having water and ice in the door kinda like breathing. I have a water treatment system with ceramic filters and UV so I’m good there. 99% of the folks there don’t have safe municipal water so there’s not a market for water/ice in the door fridges.
The necessity of this design is to avoid having a high wattage xfmr sucking up battery 24/7.
The compressor is variable speed with an inverter board attached to it. As you can see on the diagram, 120v is supplied constant and control voltage from the control board +12vdc and pwm signal possibly. I notice that the compressor only ramps up and down but nothing in between like a pure inverter fridge or HVAC.
My original idea was to use 2 step down xfmr’s , 1 low wattage to power the control board (on 24/7) and the other of sufficient wattage (on when called) to power the compressor powered on by a relay from from the compressor output on the control board. Output from step down xfmr tied to compressor.
Since the output from the control board is different, how do I approach this dilemma. When I have more time I want to see if the 12vdc is there constantly or only when called by thermostat. In that case I could make a circuit to energize the xfmr to supply ac for the inverter. If not, is there a way to tap into/sense the signal line without interfering and do the same task needed.