Hi all,
I've been looking for a simple circuit to sense if water is present at a steel probe (a bolt!).
I found a nice simple comparator based circuit that ties one input of the comparator high via a 1M resistor, this input is also connected to the probe, ground of the comparator is connected to a immersed probe.
The other input is set at 1/2 supply voltage, the idea being output changes when the water makes the circuit to ground and switches the comparator.
I'm going to use a pic with onboard comparator, thinking about it will use stainless bolts for probes.
Any problems apart from a tiny bit of plating? Seems to simple to be true compared to some other circuits I've seen?
Cheers Geoff
I've been looking for a simple circuit to sense if water is present at a steel probe (a bolt!).
I found a nice simple comparator based circuit that ties one input of the comparator high via a 1M resistor, this input is also connected to the probe, ground of the comparator is connected to a immersed probe.
The other input is set at 1/2 supply voltage, the idea being output changes when the water makes the circuit to ground and switches the comparator.
I'm going to use a pic with onboard comparator, thinking about it will use stainless bolts for probes.
Any problems apart from a tiny bit of plating? Seems to simple to be true compared to some other circuits I've seen?
Cheers Geoff