Country house. Well with pump + storage tank. If you are too lazy to turn on the pump, then you need an automatic switch. The task is as follows: it is necessary to turn on the pump in the well when the water in the storage tank (for example, a barrel) drops below a certain level, and turn off the pump when the water is filled.
Storage tanks are different in size. Wells are also different. You can inadvertently drain the well if you do not turn off the pump in time. And the pump itself is also not accustomed to working without water.
Therefore, you still need to be able to temporarily turn off the pump in the well if the level has dropped and allow it to turn on if the level is normal.
There are many electronic circuits on the Web that monitor the upper and lower water levels. From simple ones (a couple of transistors) to microprocessor ones. We will not consider them. The principle of electrical conductivity of water is often used as a water level sensor. Those. these are, as a rule, electrodes in direct contact with water. Their downside is that they tend to oxidize, lose contact with wires and other delights of finding "pieces of iron under potential" in water.
This article discusses the implementation of a non-contact sensor from improvised materials.
After my pump once again did not turn on, I decided to make something more original as a sensor than three pieces of iron in the water.
To make one such sensor, you will need:
- Polypropylene pipe for water with an inner diameter of 25mm. A metal-plastic pipe is not desirable, because it can be inadvertently quite easily deformed, but if carefully, then it can be.
- A pair of sensors for opening the door (we remove two reed switches and a magnet from them)
- Cork stopper from a bottle (wine or other suitable). The contents of the bottle are not so important, the main thing is that it does not interfere with further work.
- Cord of the desired length, heat shrink tube, a pair of nylon ties, string and electrical tape.
In general, nothing scarce, everything was found in the barn.
The first thing to do is to drill (dig) a hole in the end of the cork to insert a magnet inside.
After the magnet is inserted, you need to check that the cork flies freely inside the pipe. Most likely, this is not the case. Therefore, by rubbing the cork against a file or sandpaper, we reduce the diameter of the cork.
It should turn out something like this:
For better sliding inside the pipe, the cork can be varnished (for example, yacht varnish) by dipping.
Because the varnish will add some thickness to the cork, you need to adjust the diameter of the cork with a margin. I have a cork diameter, together with a varnish coating, less than the inner diameter of the pipe by about 3 mm.
Next, we solder the extracted reed switches to the wires, put them in heat shrink and plant them. The distance between the reed switches corresponds to the difference between the lower water level in the well (when you need to turn off the pump in an emergency) and top level when it is allowed to be enabled again.
To prevent water from penetrating inside, the upper edge of the heat shrink should go over the wire and firmly wrap around it. Therefore, it is better to use a wire with a round section.
The heat shrink should go from the wire that goes to the sensor over both reed switches and end about 5 cm after the bottom reed switch.
We make the lower edge of the heat shrink by about 5 cm more than necessary, and after shrinkage we bend the tail up, fixing it in this position, for example, with another piece of heat shrink.
We collect. Heat-shrinkable reed switches are attached along the tube by any convenient method (nylon ties or electrical tape). In the case of the use of screeds, it must be taken into account that in cold water they can shrink and either burst themselves or damage something. Therefore, do not tighten them too much.
Above is exactly the same limiter so that the cork does not float out of the pipe. The limiters must be set in such a way that, resting on them, the cork is opposite the reed switch.
More or less like this:
The assembled structure must be tied to a rope and can be used.
It turns out like this:
Before lowering into the well, we connect everything to the pump control device and check the operability by turning the pipe over.
The plug should move freely and, when reaching the reed switches, turn off / turn on the pump.
We lower the pipe into the well to the end (the lower reed switch is just below the level of the pump). We turn on the pump and try to suck out the well. As soon as the pump starts to grab air, we raise the tube until the plug drops to the lower reed switch and turns off the pump.
We raise it a little higher so that the pump turns off a little earlier than the water runs out and so we fix it. Accordingly, when there is enough water in the well, the plug will turn on the upper reed switch, which allows the pump to work again.
A similar device is installed on the storage tank. It turns on the pump when the water in the tank runs out and turns it off when the water is filled.
True, this device has some technological features:
- The device is not located inside the tank, but outside and works according to the method of communicating vessels.
- In this case, the upper limiter can be omitted, it is enough that the pipe is slightly higher than the upper edge of the tank
- It will not be possible to use two holes and a screed as a lower limiter (water will flow out). Therefore, the lower limiter is the pipe bend.
Unfortunately, we were unable to photograph the actual structure installed on the drive. So I'll show you a schematic.
To regulate and control the level of a liquid or solid (sand or gravel) in production, in everyday life, a special device is used. It is called a water level sensor (or other substance of interest). There are several types of such devices, which differ significantly from each other in the principle of operation. How the sensor works, the advantages, disadvantages of its varieties, what subtleties you should pay attention to when choosing a device and how to make a simplified model with a relay with your own hands, read in this article.
The water level sensor is used for the following purposes:
Possible Methods for Determining Tank Loading
There are several methods for measuring liquid level:
- Contactless- Often devices of this type are used to control the level of viscous, toxic, liquid or solid, bulk substances. These are capacitive (discrete) devices, ultrasonic models;
- Contact- the device is located directly in the tank, on its wall, at a certain level. When the water reaches this indicator, the sensor is triggered. These are float, hydrostatic models.
According to the principle of operation, the following types of sensors are distinguished:
- float type;
- hydrostatic;
- capacitive;
- Radar;
- Ultrasonic.
Briefly about each type of device
Float models are discrete and magnetostrictive. The first option is cheap, reliable, and the second is expensive, complex in design, but guarantees an accurate level reading. However, a common disadvantage of float instruments is the need to be immersed in liquid.
Float sensor for determining the liquid level in the tank
- Hydrostatic devices - in them all attention is paid to the hydrostatic pressure of the liquid column in the tank. The sensitive element of the device perceives pressure above itself, displays it according to the scheme for determining the height of the water column.
The main advantages of such units are compactness, continuity of operation and availability in price category. But it is impossible to use them in aggressive conditions, because contact with the liquid is indispensable.
Hydrostatic liquid level sensor
- Capacitive devices - Plates are provided to control the water level in the tank. By changing the capacity indicators, one can judge the amount of liquid. Lack of moving structures and elements, simple circuit devices guarantee durability, reliability of the device. But it is impossible not to note the shortcomings - this is the obligatory immersion in a liquid, the exactingness of the temperature regime.
- Radar devices - determine the degree of water rise by comparing the frequency shift, the delay between the emission and reaching the reflected signal. Thus, the sensor acts as both an emitter and a reflector.
Such models are considered the best, accurate, reliable devices. They have a number of advantages:
The disadvantages of the model can be attributed only to their high cost.
Radar tank liquid level sensor
- Ultrasonic sensors - the principle of operation, the scheme of the device is similar to radar devices, only ultrasound is used. The generator creates ultrasonic radiation, which, upon reaching the surface of the liquid, is reflected and after some time enters the sensor receiver. After small mathematical calculations, knowing the time delay and the speed of the ultrasound, determine the distance to the surface of the water.
The advantages of the radar sensor are also inherent in the ultrasonic version. The only thing, less accurate indicators, a simpler scheme of work.
The subtleties of choosing such devices
When buying a unit, pay attention to the functionality of the device, some of its indicators. The most important questions when buying a device are:
Options for sensors for determining the level of water or solids
DIY liquid level sensor
You can make an elementary sensor to determine and control the water level in a well or tank with your own hands. To perform a simplified version, you must:
A do-it-yourself device can be used to regulate water in a tank, well or pump.
After installing a new barrel of a larger volume on a summer shower, it became necessary to install some kind of "sensor" of the water level, so as not to constantly climb onto the roof of the shower, and besides new barrel equipped with a lid, which is fixed with a clamp, and you don’t really want to constantly remove it and see how much water is left. Therefore, I installed such an easy-to-make device.
Necessary materials:
Styrofoam (such a piece as in the photo, I found in a box from gas stove, they dig up camphor during transportation.);
- small nut
- large nut
- a long screw;
- two pieces of plastic strip;
- fishing line.
Sensor manufacturing
First of all, we drill through hole in the middle of the foam (this is done so that when we tighten the screw, the foam does not split), as well as on both plates.
Then we fasten the parts as shown in the photo:
View from above:
Bottom view:
We fasten the fishing line to the screw and our “sensor” is almost ready.
Now we carry everything to the roof of the shower, drill a hole in the tank lid (the hole must be made in such a way that the fishing line passes freely through it).
And here is the finished result.
Principle of operation our "sensor" is very simple. When the water in the tank runs out, our float goes down, and the washer on the outside goes up, therefore, you need to add water. And when the water is poured, it is also very convenient to follow. Of course, you can make markings on the tank and hang some kind of arrow instead of a puck, but this is a personal matter for everyone. If you have any questions, please ask!
Thank you for your attention!
With the advent of the spring-summer dacha-garden season, the seedlings need water and irrigation. Of course, it is better to water more often, but not everyone, of course, manages to regularly come to the dacha to water vegetables. Before watering, water must be defended with cold water from the tap is absolutely impossible, because you can ruin everything in the bud. Usually summer residents collect water in large containers, barrels. During the time that you are on the site, the water is turned on, it is being collected, and you yourself are messing with the beds. But it often happens that we got tired and forgot to turn off the water, went home for two days, returned, and there was a flood and the neighbors were all flooded. An unpleasant moment, of course, but if meters are still installed on the water, this is generally a horror. So our author got into such a situation and decided - something needs to be done about it. And the idea came to mind to make a signaling device for filling a barrel of water with your own hands. He did not want to buy a device for money and began to develop a signaling device. The driver's "anti-sleep" signaling device was taken as the basis
And so what next will the author need for his design.
Materials: signaling device, wire, tennis ball, plastic tube.
Tools: Glue gun, pliers, hammer, screwdriver.
The principle of operation of this signaling device is that when the driver begins to fall asleep and his head tilts, an audible signal is triggered. Operation occurs due to a mercury ball enclosed in a flask with contacts, when tilted, the ball rolls down and closes the contacts and a signal is triggered. Here is the disassembled device.
The first step of the author is the preparation of the wire.
Then the author puts a plastic tube on the flattened end
Such a loop was made on the wire for subsequent fasteners.
Then, at one end, the author glues a signaling device with a glue gun.
Glue a tennis ball to the other end, which will act as a float.
The author attaches this design to a column, for a hose near the barrel, like this.
And as the container is filled with water, the signaling device deviates to the bottom, thereby simulating a falling asleep driver.
When full, the inclination angle will become maximum and an audible signal will sound.
After the container is filled, the alarm can be removed so that it does not get wet in the rain or thieves do not steal.
In industry and everyday life, there is always a need to determine the different levels in containers. Level sensors are used for these tasks. various designs. Depending on the filling medium of the tank, one or another sensor is used, sometimes, for the sake of simplicity and saving money and time, combined sensors are used, that is, they are made by hand. These are simple designs that use sensors of completely different types in their composition. Basically, such sensors are used where there is no easy access to the measurement environment or the measurement site is very aggressive for human health.
Types of level sensors
Most modern level sensors have an electronic relay with a converter in their design. The electronic circuit is designed to convert the measured value into a standard signal. The signal can be analog or digital. Analog can be current 0..20mA and signal called current loop 4..20mA or voltage 0…5V, 0..10V.
Level sensors are used to protect the pump motor from dry running, they regulate the motors of pumps of wells that fill any containers with water and not only in the system of cold and hot water supply.
DIY water level sensor
Let's see, using the example of pumping water from a pit, how it is possible to make control in the automatic cycle of maintaining the water level not higher than it should be.
We have a pit with a very unclean liquid, consisting of water and coolant impurities for the cutters of a metal-cutting machine.
All types of sensors were considered, however, for the price and ease of execution, a combined design came up, consisting three meters long wire(pit depth), attached to a float (a large plastic container with air), on the surface the wire is attached to a spring with a petal.
As a signal, a conventional discrete signal of 24V is taken from a conventional inductive sensor. He works on a petal. When the water level in the pit rises, the float rises, releasing the spring. A petal is attached to the end of the spring; it rises due to the unbending force of the spring. In turn, an inductive sensor works on the petal, feeding the pump motor relay to the coil, forcing it to pump water from the pit. In order to avoid frequent switching on and off of the engine, in the sensor-coil circuit, there is a switch-off delay relay with a setting of 10 minutes.
Thus, the next time the sensor is triggered, the relay will work again and the cycle will repeat.
Of course, to protect the engine from dry running, it is advisable put a leak sensor in the pipe through which the emulsion is pumped out. But in our case, the simplicity of the design was important. Instead of an inductive sensor, you can use two plates in contact with each other, which will be even more economical.
If the water or other liquid has a homogeneous composition, then you can apply the end who metric single electrode level sensor.
For example, DU-1N manufactured by "Relsib", designed to measure the level in various types liquids. The sensor can operate over a wide temperature range. The case is not exposed to corrosion, consists of high-quality stainless steel. Ceramic and PTFE are used as insulation, which provides excellent insulation protection. Resistant to many mechanical loads. The measurements are independent of the density of the liquid. And does not require additional care during operation.