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I have an espresso machine that I tore down, reassembled with fewer components then modified it to fit a specific setup -- kind of DIY project.
The machine has an autofill circuit. After I removed the controller and SSR, the machine does not have an autofill circuit, which is fine when I turn on the pump to refill manually. The only problem is checking the water level to find out when I need to refill the boiler. I fitted a sight glass for that purpose, but I still need another aid to notify me whether the water level is OK or not, mainly in case someone else is using it.
I want to add a small buzzer/LED which is activated only when the water level drops below a certain point, OR just a LED which lights up so long as the water level is fine.
There is a water level probe. The boiler is grounded so if there is water touching it there will be a circuit/current through the probe, and if water is below the tip then there is no circuit (this is my understanding, so please correct me if it is not correct.)
There are buzzer/LED gadgets that can be bought cheap, but I want to know how it would work with the water level probe? I tried connecting the probe to a LED then to one of electric current poles; I thought it should light up when there is water touching the probe, but it does not seem to work, or maybe it is just the wrong way to do it. :)
Any help is appreciated.