/diy/ - Do It Yourself

Cut the end off an extension cord. Plug in, poke the exposed end at suspected wet areas.

>>1595276
>Essentially I need something that’ll complete a circuit when coming in contact with water

what sort of circuit. what will the presence or absence of water do? most water has enough conductivity to be detected by any sort of metallic probes. for long term life I would use stainless steel.

>>1595276
Literally all materials have this property, to some extent.
Concrete, semen, kool-aid powder, table salt, wood. etc.

>>1595300
>>1595311
I’m sorry I wasn’t more clear it’s going to a low voltage alarm and the voltage isn’t strong enough for water to complete the circuit alone

>>1595314
Back about 100 years ago scientists developed a special kind of vacuum tube that was able to control the flow of electricity by using a *different* flow of electricity. One could have a small signal, and make it into a big signal. The amplifier was born! Eventually this was called the "thyratron" This began a long march in technology that led to different types of vacuum tubes that could also perform this switching function, and eventually to the transistor effect. We can now make devices that use this transistor effect to amplify absolutely tiny signals to very large signals.
This same kind of amplifier technology is used in basement water detector circuits, which you can easily find by searching.

>>1595314

use a comparator to drive a transistor and perhaps a relay might be needed if you ever get around to telling us about the circuit.

>>1595276
to say, sound an alarm or something like that?

>>1595276
I did an experiment many years ago where I was trying to draw high value resistors on a PCB using regular pencils. If I remember correctly the resistance changed greatly whenever I exhaled on it from what I assumed must've been the moisture in my breath. An amplifier like this asshole >>1595318 is talking about could be hooked up to such a resistor and a microcontroller or comparator could monitor the current output of the amplifier to do what you are talking about.

Or if you're just looking for a flooding sensor then what we use at work are two metal plates with a small air gap called beetles. And yeah obviously amplifiers are involved because you don't want high currents flowing through water in a flood.

>>1595276
Flesh.

>>1595314
>it’s going to a low voltage alarm and the voltage isn’t strong enough for water to complete the circuit alone

a clothspin
two thumbtacks
an aspirin
wire to connect alarm

strip ends of wire
wrap one wire around stud of one thumbtack
wrap other wire around stud of other thumbtack
press thumbtacks into jaws of clothspin
connect other ends of wires to alarm
insert aspirin between thumbtacks
place in area to be protected from water

Here's a circuit that turns on a buzzer and LED when moisture is detected
>https://circuitdigest.com/electronic-circuits/soil-moisture-sensor-circuit-diagram

>>1595491
This unironically is one of my more favorite 'safety' devices.
It starts to howl low when the battery dies unlike the other cheap brand I tried that gave no warning that the batteries were exhausted.
I keep one under each sink, and one near the hot water heater.
Sure enough the kitchen one went off when the dishwasher's waste hose started to leak.
>>1595558
This one also works well if you want to make you own as an experiment.

>>1595276
Non-contact capacitive sensors work well for detecting water. For example, mounting some electrodes (copper tape) on the outside of a plant pot will readily detect the water content inside