Detecting Water Flow in Sprinkler System

Good idea. I'll see if I can find that. Any idea how much the pressure should drop between flowing and not flowing?

If you put it on the delivery side of the valve your closed pressure will be the height of the lowest sprinkler above the sensor / valve.

The open pressure will be working pressure + friction.

You will need an isolating switch to prevent alarm when you do irrigate.

You may have to protect your sensor from over pressure.

the sensor will register zero pressure when at the same height as the sprinklers.

There are good pressure sensors available to buy as well.

What type of sprinklers are you using?

Hmmmmm how about sensing the flow of water inside the house in the pipe going to the tap (faucet)...?

Something like an orifce plate to generate a noise as water flows... or a small cheap turbine to make a noise when water flows... No electricity, nothing complex to go wrong...

Or maybe a temperature sensor (small thermistor) on the pipe leading to the faucet, so as the water flows the temperature drops and reaches a set point to operate an alarm...?

John...

Thanks but this won't work in this case. It's my sprinkler water line and it never enters the house. My house water line make a LOT of noise whenever water is running but the sprinker one is completely silent in here. The pressure switch idea might work.

if you look at fire suppression systems (sprinklers), there are loads of very inexpensive flow detectors that tell you when the water is on. Most have a SPDT switch on them that you can attach to any load.

hi there

well there is a few idea here that i have being in the irragation myself what i have is when im watering or useing the sprinklers well if you have over 80,000 plants that needs water you can't have any problems

ive got two computers running the whole lot that and there are sensor pick up all over so if the pressure drops at any point at any sensor i alerted to the area were its happend

the sensor ive got is under ground self built i use moton sensors that can pick up a speck of dust going past them it works well

ok about the water delivery system ive got a huge plant that recycles water this is backed up by a pump so if any thing fails to come in when its needed im alerted

Canderous, thanks for your post. The original question was what to use for a sensor that does not require power to it. What do you use for sensors? It sounds like you have a home built but commercial system there and it's all wired together. I could do that but it's a lot of work for this use. One suggestion I got was to not try to detect the water at all but to use a wireless camera and detect image motion in my computer since my problem is not leaks but people turning on the faucets, either to steal water or as a prank. The suggestion to use the camera is interesting because if it works, I'd have a picture of the trespasser for the cops (or my cousin Guido) as a bonus.

use two bar like bamboo material with a matel piece on their terminal. as the bar has elesticity, when water flow, they will contact together, so the electric current get throw when they link to a power. then alarm, then thats all...

only one cent or no need money...

Thanks cnpower. How do I get the two bars with metal terminals inside of the half inch plastic pipe and how do I get the wires out? How do I stop the water from short circuiting the terminals? You must be envisioning something that I'm not.

Plastic pipe!!!!!!!!!!now your talking, cause a minor flood around the area under the hose connection. Run a 120 VAC wire through the wall and connect it to the handle. Make sure you have driven a copper rod into the ground in the flooded area and connect it to the ground buss on your house. This will cost you a little flood water but the thief will not return.

He won't leave either! But our friend needing an alarm will; straight to jail for murder.

j.

wow, its terrible.

theif is still man. he willl be killed.

he also has human rights.

In this country it's the dog's rights. In some areas it's unlawful to chain a dog indefinitely (other than briefly under more or less supervision) to a stationary object.

Look at the illustration. you can use even two thread with two metal foil and bind on the tap, no water, they are splitting. when water flow, basised on Bernulli law, the more speed the flux the close the foil are getting. Now they are getting contact with each other time to time. the wire which connect the foil willhave current time to time when power supply apply to.
you can apply an solenoid valve from wash machine to the tap or pipe. so that, when water flow, the valve get crueent and turn off, when water stop, it can turn on.you can also use a relay to keep it on turning off station.

??

A normal sprinkler system has an alarm valve to detect water flow.

At least when I speak about sprinklers I think of an automated fire suppression system, where it is normal that you want to be warned of an activation.

Are you saying some one is turning on your sprinkers? Or disabling your sprinklers? Irrigation sprinklers? Other?

No, they are not activating the sprinkler solenoids. That controller is locked in the garage. They are turning on spigots I have piped into the sprinkler piping which I use for hand watering with a hose. It's either water theft by neighbors who better hope that I don't catch them, or vandalism - ditto.

In your situation, if the faucet location allowed, and if I had an extra circuit available in the control box, and if I had a relay and a photosensor...I might be inclined to install another solenoid unit and its own pop-up sprinkler. The control box circuit timer would be programmed for interval sufficient to keep solenoid shutoff disengaged during whatever interval the prowler comes around. The only thing that would keep the sprinkler from actually sprinkling seemingly incessantly would be a relay interrupt in its control valve circuit. The relay, however, would enable/disable control current to the solenoid (to open the valve) whenever the water vandal, when approaching to turn the faucet valve, interrupts the photo sensor. The sprinker itself would be so situated that whenever the water weenie came to take or waste water, he would get a shower--a soaking--as well.

Unfortunately I'm at the capacity of my sprinkler circuit box. Replacing it with a larger one, running new wires several hundred feet and installing the solenoids would all be quite a bit of work or quite expensive to have it done. That's why my original post asked for a wireless solution. I'd happily replace the batteries once a year for this purpose rather than spend upwards of a thousand dollars for a new control system.

So far the simplest, cheapest and lowest tech solution is to remove the handles if I can convince my wife to go along. Installing a washing machine pressure switch and a wireless doorbell is the next workable. It's a true low cost hobby gadget solution but a fair amount of work and it's possible there won't be enough pressure drop to activate it. A wireless camera is the most complex that satisfies the no wires need and doesn't require messing with the water pipes but it's most useful if it works because of the satisfaction of getting evidence.

I may just do a project selection matrix chart on these and see how the numbers come out. I teach quantitative decision making and this would make a good classroom example.

BTW, I take the solutions that lead to harming the thief as joking around. Don't get your panties in a twist over them! There is real value in proposing outlandish solutions when brainstorming because often in the creative process of doing that, the solutions often contains workable elements for a truly useful solution!

Okay, how about a sign that says something like: "If you need water, please knock on door and ask."

Or: "Mess with this faucet again and I'm telling your parents!"

Why didn't I think of that? I can store the handle and a small screwdriver in a small bag near the door to take when we need it.

"Why didn't I think of that?"

Too obvious. Way less effort than any of the others, but not as much fun as some of them. BTW, you could step down the 110V to enough to rout but less than lethal.

haha, its very useful way. very simple and many people have used it in the past. they lock their tap by a lock, when they use water, they open it with their key.