Simple Water Sensor

Intro: Simple Water Sensor

I will Teach you how to make a simple water sensor circuit

Step 1: Gather Parts

Parts List
1 General Purpose NPN Transistor $0.10
1 50K Trimpot $0.15
1 47ohm Resistor $0.01
1 LED $0.08
1 Proto Board or You can etch A PCB
1 3 volt power source battery, wall wart, whatever

Step 2: Learn the Layout

[Play Video]



Read Circuit Diagram

Step 3: Create PCB (skip Step If Using Proto Board)

The Schematic is made with ExpressPCB which is a free PCB Layout Software you can download it here
Than Download the PCB file and open and print it and make your PCB. Here are a few links to Instructibles that show you how to make a PCB
water sensor.pcb is 3v
water sensor2.pcb is 12v
these PCB schematics are free to use if I see them being sold buy anyone but me you will be contacted
5pcb
Cheap and Easy Toner Transfer for PCB Making
The Saltwater etch process

Step 4: Build It

Build time will update once I make the PCB

Step 5: Connect to HHO Cell or Any Other Water Sensing Probe

Here are some mock ups of how to connect it to a HHO Cell or just detect water.

Step 6: 12 VOLT CIRCUIT

Here is how to setup the circuit to run on 12 volts from a car battery the circuit is still the same just some resistors are added to the probes to protect the transistor and a larger resistor to protect the LED

Share

Recommendations

  • Furniture Contest 2018

    Furniture Contest 2018
  • Metalworking Contest

    Metalworking Contest
  • Fix It! Contest

    Fix It! Contest

60 Discussions

0
None
DaveJ96

11 months ago

Really like this and mr_man's comments are great too. What I am hoping to do is to but a system to check 5 separate points in the house for leaks, and have a small board on the wall with a red and amber led for each location a green system light and run through a raspberry pi or arduino uno. The idea being that for each location if it is leaking at the time the red led is lit, if it has leaked but is not now, then the amber light is lit. The green system light will be lit if the system is running and there has been no leak at any point since last reset. A button to reset the system on the board would be good too. I can do the programming either Arduino or Raspberry pi but the electronics are eluding me. ideally would be a 3v3 system for the raspberry pi without doing voltage changes and also taking into account the points raised by mr_man. Any help would be much appreciated.

0
None
T448

1 year ago

Any ideas why my LED would remain on all the time regardless of the moisture on the sensor? What have I done wrong?? Driving me nuts! Thanks

0
None
DavyZ

2 years ago

how do you prevent corrosion on the wires? I want to use it in the ocean and corrosion will be a problem.

5 replies
0
None
Cyberscann54DavyZ

Reply 1 year ago

I just was looking over the comments and the pencil leads are a good idea but brittle get some cheap heavy-duty batteries AAA to D no 9V they have carbon rod's in them and are not dangerous to disassemble the don't corrode or rust and are conductive and really cheap if you are in the USA you can get 8 AAA OR AA for a $1 at most $1 stores

0
None
vamsikurreDavyZ

Reply 2 years ago

Even I have similar plan and did some reading about "Electrolytic corrosion" and found out that inert metals like platinum or gold dose not corrode. but they are a bit expensive for me :) So I am planning to use a good stainless steel rod's as probs as they corrode and eaten away very slowly compared to copper and aluminium. I think graphite (pencil lead) also makes good electrode.

0
None
MG17vamsikurre

Reply 2 years ago

If you're doing this for drinking water DON'T USE STAINLESS STEEL !!!

I was going down that path too, thinking that there will be little/no corrosion, but then I noticed a strange substance in the water. Turns out that using stainless steel as electrodes is a bad idea as it releases a poisonous substance! ...

See http://antique-engines.com/stainless-steel-electrodes.htm

0
None
TibiA1DavyZ

Reply 2 years ago

look for stainless steel wire used for welding and use terminal board for conexion

0
None
cihanc1

1 year ago

Hi. I need to use this with raspberry pi. Raspi pins operate in 0 - 3.3v. so which
resistor value do i need. I ask if i have to change 47 ohm R. Then i willl
connect raspi pins to where the led is and then read value with wiringpi functions. Right? Thanx

1 reply
0
None
Cyberscann54cihanc1

Reply 1 year ago

if you are going to use this with a raspberry pi you will use the 3v circuit without the LED and 47ohm resistor or you can keep it as is with the LED and resistor. if the pi is powering the circuit you can attach a wire between the collector of the transistor and the LED and put it on one of the input pins and you can put a resistor in the input wire to ensure the maximum current going to the IO pin don't exceed 16mA

0
None
NealP5

2 years ago

How would I modify this to "press" a button instead of the led? I am considering coupling this with a dash button for an ultra cheap smart sensor! So how would I make this activate the button?

5 replies
0
None
Cyberscann54NealP5

Reply 2 years ago

To better help you what does the button do. What does it turn on or off. Is it in series(a switch wired in line with the + or -) with a pump is it a button of a control board(circuit board). Depending on this it could be as simple as an other transistor or a Mosfet transistor (can handle more power) or a relay switch (a lot more power)?

0
None
NealP5Cyberscann54

Reply 2 years ago

I'm filling 5 gallon bottles with a slow 50GPD reverse osmosis system in a kitchen that is 100 degrees most of the time. I want to have it notify me when the bottle is almost full as I have forgotten and flooded the damn kitchen 3 times now.

0
None
NealP5Cyberscann54

Reply 2 years ago

it's just on a tiny circuit board. It's the button on the Amazon Dash Button. I wanted to make this as cheap as possible and these sell for only 5 bucks.

0
None
Cyberscann54NealP5

Reply 2 years ago

so is the button to be activated when a liquid product gets low if so this sensor circuit won't work. what is the dash button doing ordering a product or some modified use i will create a circuit to fit your needs to work with the button

0
None
fthebunny1NealP5

Reply 2 years ago

A pull up resistance would made the job. It's very simple : electricity is lazy, really lazy, so it will always take the shorter, easier path. A resistor is a kind of hill, so it is harder to take, than a wire, which is a flat, right lane. A pull up resistance, makes the path to the Vcc, harder to reach, than GND. So it keeps your input to GND. But if you cut the wire, the electricity will pass by the resistance, and give a HIGH state to your input on your dash button.

Now, if you need it to be a short impulse, not a continue one, you must look about the 555, the most famous timer of all time. It will create the impulse, once, even if it still high at its input.

0
None
fthebunny1

2 years ago

Great project ! I was seeking something like this since a while, but just found the good search terms now ^^.

I have a question, does this :

Wouldn't be cheapest ?

0
None
EmerSonE3

2 years ago

Can you show me the diagram in PCB ?

0
None
aphy101

2 years ago

Hi we are planning to use this circuit in our project but how do we calibrate it?
Thanks