Icemaker technical question for you electronics experts

[MikeP]

I bought an icemaker earlier this season and I posted some stuff about it a while back, including the fact that quit working - then worked, then quit, etc.

OK...today I discovered the problem; If I use distilled water it will quit. If I use non-distilled it will run fine. Distilled water produces clear ice; non distilled produces cloudy ice.

The reason it quits with distilled is that at the water nozzle where it dumps into the icemake tray, there is a pair of wires. One is connected to the metal (ungrounded) nozzle, the other is connected to a metal (also ungrounded) splash plate that the water sprays onto as it goes into the icemaker tray. Apparently, these wires are part of a sensor that detects water flow based on resistance. If there is no resistance, the machine thinks there is no water flowing and it shuts down the water pump after a few seconds instead of having it run for 15-20 sec to fill the tray.

SO...I want to use distilled water but distilled has no minerals so it does not flow any current and the sensor sees "nothing." Could I wire a resistor between the two wires to fool the machine into seeing water? There is 4.3VDC in the circuit. How could i determine what value resistor would work? I'm assuming that just jumping straight across the two wires would damage the sensor but I don't know if that's true...

 

[Kiwipushrod]

Take an ohmmeter, set the probes in non-distilled water at the same distance as the sensor wires on icemaker....record ohm reading.

Proceed down to the local Radio shack, purchase resistor. Temp resistor in line with alligator clipped jumpers. Invite Me over to sample Your finest scotch on clear ice.

Kiwi

 

[Dan Mapes]

I'll second that. Just watch the ohm meter since the value will change. It could take a couple of passes to get it right. Perhaps use a potentiometer with a range around the measured value so you can adjust it a bit.

By the way did you speak with the manufacturer? Perhaps they know about this and can make a suggestion. I'd start there first, and if they blow you off the above is about as good as it gets.

 

[MikeP]

Thanks guys! The manufacturer is (surprise, surprise) Chinese. The supplier has no clue...

 

[SeaEric]

Perhaps a drop of Soy Sauce in the distilled water will make a difference.

But seriously- I'm continually amazed by the tech knowledge here. Not to mention some of the questions.

 

[Kiwipushrod]

Before we all congratulate ourselves......There's is a problem!

I'm gonna guess that the sensor is to let the processor know that there is water in the tray and quite possibly it's a level indicator.

It cannot use a float switch because the float would freeze in to the cube.

If we leave the sensor jumped one of 2 things is going to happen and one has to do with water all over the deck!

Kiwi

 

[MikeP]

It seems to me that the pump starts, then, if the sensor doesn't "see" any water, the pump stops. However, if the sensor sees water, it continues to pump for 20 seconds or thereabouts. So, IMO, I believe their is some sort of timer that, once water is seen, the timer "takes over" and allows the pump to keep running even if the sensor no longer sees anything. I BELIEVE, that once the sensor sees the water, the pump timer then runs for the required time. But within the first 5-10 seconds the sensor has to see water. But after that has occurred, the timer takes over.

I'm just guessing at this based on what I have seen. When filled with distilled water, I took a piece of paper towel, soaked in in "regular water," and laid it across the nozzle/shield, and turned on the unit. Despite having distilled water in the unit, the pump stayed on for the normal cycle.

So I think that if the sensor leads were shorted or had an appropriate resistor, the pump would still only run for the specified number of seconds.

 

[Kiwipushrod]

Hey Mike, I thought about it being on a timer too, but it would have to know water pressure or have it's own regulator to be precise on the fill level.

I'm probably overthinking it. So don't follow My advise because I break stuff all the time.

I'll bet spcoolin knows exactly how it works.

Kiwi

EDIT: I missed the part about it's own pump..crap.