Component suggestions - Float sensor

Thread Starter

icydash

Joined Jan 14, 2009
148
Hi all,

I'm trying to build a simple circuit where a float sensor turns on or off the circuit, like the following:schematic.jpg
Ideally, I'd like the circuit to be off until the float sensor is lifted, and then have the circuit become powered. I bought this on Amazon: https://www.amazon.com/gp/product/B00909404Y/ref=oh_aui_detailpage_o04_s00?ie=UTF8&psc=1 ... but it doesn't seem to be working. I'm not sure if it's only for AC or the 9v battery just isn't enough power. Does anyone have any suggestions for a float sensor that might work?

Thanks!
 

MrChips

Joined Oct 2, 2009
30,706
A float sensor should just be a mechanical switch.
Take a multimeter and set the range switch to measure resistance (ohmmeter).
Measure the resistance by connecting the ohmmeter leads to the two leads of the switch. Manually operate the switch between the two positions, ON and OFF.
 

Thread Starter

icydash

Joined Jan 14, 2009
148
I think these sensors (at least the one I bought) may work by induction. I know there's a magnet in the float piece, so I think it had something to do with that.
 

MrChips

Joined Oct 2, 2009
30,706
I think these sensors (at least the one I bought) may work by induction. I know there's a magnet in the float piece, so I think it had something to do with that.
If it has a magnet then it would be using a reed switch if there are only two wires.
A Hall Effect switch would have three wires.
 

Thread Starter

icydash

Joined Jan 14, 2009
148
Weird. I just tested it and it all seems to be working now. Don't know what the problem was, but thanks for your help!
 
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