Using your favorite 555 timer, you can make a sensor for water, for washer, antifreeze, etc. It should be noted that such a sensor is useful both in your car and in everyday life. The scheme is quite simple and repeatable. The microcircuit has become widespread precisely because of its simplicity.

The circuit will be used for the water sensor.

The operation of the device is extremely simple. When the electrodes are immersed in liquid, C1 is a capacitor, shunted. When the electrodes are in the air, the shunt disappears and the microcircuit begins to work.

Square-wave pulses emanate from the microcircuit. With the help of such impulses, it is possible to control with a larger load. For example, you can send a signal to a light bulb through a transistor. This technology allows you to include an alarm or indicator in the circuit. With the help of the latter, you can determine the presence of water in the tank. A similar sensor can be installed both in the tank and in the radiator. Sensor power supply - 12 volts. This suggests that there will be no issues with nutrition.

As a rule, the sensors are made of fiberglass. But most often they use ordinary copper (wires). For the sensor, two identical pieces of wire with a cross section of 1 millimeter are suitable. It is important to note that you need to clean off the varnish from the wires, which may be on the metal surface. This is done with fire or sandpaper. So, the length of the wire should be up to 3.5 centimeters.

To keep the wires in the plug, they are reinforced with silicone. Then the wires are attached to the microcircuit itself. The wires in the cover can be connected to the microcircuit with thinner conductors.

The microcircuit can be hinged - without an installation board. When everything is ready, the resulting device is closed with another similar lid. The connection of the covers must be sealed with glue or other means.

Thus, without incurring unnecessary costs, you can independently make a sensor that will help not only in the car, but also in everyday life. So, you can save yourself from frequent rises to the shower in order to see the water level in the tank. A homemade water level sensor will solve the problem. It is only important to do all the work carefully and carefully so that the device works properly.

To regulate and control the level of liquid or solid matter (sand or gravel) in production, in everyday life, a special device is used. It is called the water level sensor (or other interesting substance). There are several varieties of such devices, which differ significantly from each other in their principle of operation. How the sensor works, the advantages, disadvantages of its varieties, what subtleties when choosing a device should be paid attention to 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 the tank load

There are several methods for measuring liquid level:

1. Contactless- often devices of this type are used to control the level of viscous, toxic, liquid or solid, free-flowing substances. These are capacitive (discrete) devices, ultrasonic models;
2. 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 design, but guarantees an accurate level reading. However, a common disadvantage of float devices is the need for immersion in liquid.

Float sensor for determining the level of liquid in the tank

1. 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 senses pressure above itself, displays it according to the scheme to determine the height of the water column.

The main advantages of such units are compactness, continuity of operation and affordability in the price category. But they cannot be used in aggressive conditions, because one cannot do without contact with liquid.

Hydrostatic liquid level sensor

1. 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. The absence of movable structures and elements, a simple scheme of the device guarantee the durability and reliability of the device. But one cannot fail to note the disadvantages - this is the obligatory immersion in liquid, exactingness to the temperature regime.
2. Radar devices - Determine the degree of water rise by comparing the frequency shift, the delay between emission and arrival of the reflected signal. Thus, the sensor acts as an emitter and a reflector catcher.

Such models are considered the best, accurate, reliable devices. They have a number of advantages:

The disadvantages of the model include only their high cost.

Tank liquid level radar sensor

1. Ultrasonic sensors - the principle of operation, the circuit 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 a while falls on the receiver of the sensor. After a little mathematical calculations, knowing the time delay and speed of ultrasound movement, determine the distance to the water surface.

The advantages of the radar sensor are also inherent in the ultrasonic version. The only 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 extremely 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 DIY device can be used to regulate water in a tank, well, or pump.

After installing a new barrel of a larger volume on an outside shower, it became necessary to install any kind of "sensor" of water level, so as not to constantly climb onto the roof of the shower, and besides, the new barrel is equipped with a lid, which is fixed with a clamp, and must be constantly removed and I don't really want to see how much water is left. Therefore, I installed such an easy-to-manufacture device.

Necessary materials:

Styrofoam (I found such a piece as in the photo in a box from a gas stove, they break up camphors during transportation.);
- small nut;
- large nut;
- long screw;
- two pieces of plastic strip;
- fishing line.

Sensor manufacturing

First of all, we drill a 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 attach 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 needs to be made so that the line would pass freely along it).

And here's the finished result.

Principle of operation our "sensor" is very simple. When the water in the tank runs out, our float falls to the bottom, and the washer that is outside rises to the top, therefore, you need to add water. And when the water is poured, it is also very convenient to follow. You can, of course, make markings on the tank and hang some kind of arrow instead of a washer, but this is up to everyone personally. If you have any questions, please ask!

Thank you for the attention!

This device was developed for a septic tank of a country house, as an indicator for monitoring the filling level of the sewer. The task was to create a reliable sensor that should work in moisture conditions and in different temperature conditions. At the beginning, I thought to apply the principle of a float in a cylinder, taking as a basis a container from under a silicone (as you can see in the figure of possible versions of a liquid level sensor). But, life itself, guides and suggests the necessary paths, you just need to be able to be aware of it! Based on the fact that in my septic tank there was already a 110mm and 50mm outlet for sewer pipes, the decision came by itself. Thus, it became possible to mount the device on a 50mm pipe, excluding other mounting options. All materials must be made of plastic, aluminum, bronze, stainless steel, and so on - resistant to the environment to which you are going to apply them!

The principle of operation of the liquid level sensor is based on a magnet and reed switches. By moving the magnet along two reed switches, the sensors are triggered and, accordingly, the LEDs glow in a certain color, indicating the progress in filling the tank with liquid. I tried to simplify the product diagram as much as possible, and achieved the use of only two reed switches. It was also important to use as few parts as possible for reliable, long-term performance.

Liquid level sensor circuit

The principle of operation of the liquid level sensor

Possible versions of the liquid level sensor

The diagrams show that in the lower position of the float, when the green LED HL1 is on, the 2nd switch is activated. That is, the liquid level is below the float, which is limited by a stopper and, accordingly, the magnet closes the reed switch contacts. As the liquid level rises (filling the reservoir), the magnet moves and the 2nd reed switch switches, which connects the yellow LED HL2 and turns off HL1. When a critical level is reached, the magnet activates the 1st reed switch, the red LED HL3 will light up, and the yellow LED will turn off, notifying you that the tank is full. In case of any malfunction with the float or magnet, the yellow LED should be on (for example, float tipping or magnet mixing, stopper breakage, etc.). By adding a relay to the circuit, it will be possible to use it as an actuator for connecting more powerful loads. Also, you can connect a buzzer to the 2nd reed switch, for sound notification or a mobile phone and so on.

Power supply of the device from any source of 3-12V. For example, from telephone charging with a 5 volt switching power supply or two 1.5V batteries, a more compact 3V one is also suitable. In this case, it will be necessary to reduce the resistance of the resistor R1. Choose a smaller button or switch, although you can do without it by keeping the indicator on all the time. Mounting is hinged, in the house, for example, in an electrical panel. Carry out the wiring in advance (I already had it ready). Thus, very simple circuitry can be dispensed with, without microcontrollers, etc. After all, the simpler, the more reliable!

So, we need the following materials:

Connecting sleeve for sewer pipes PP d = 50mm х2pc.
- sewer plug d = 50mm x2 pcs.
- plastic clamp (bracelet) x1pc.
- U-shaped plastic profiles (from furniture fittings).
- shrink sleeve d = 30-40mm, d = 3-10mm.
- plastic or textolite plate = 4-6mm.
- aluminum rivets x10 pcs.
- non-uniform magnet (from the hard disk of the computer) x1pc.
- 3-pin reed switches x2 pcs.
- button or low-voltage switch x1pc.
- resistor 680-1.5k. x1pc.
- LEDs x3 pcs.
- low-voltage wires (for example, for burglar alarms, 5-core).
- a plug for 4 legs (for example, from a dimmer for RGB LED).
- hot melt glue or silicone.
- 12V power supply or 3V battery (from a computer).

From the tool:

Drill
- building hair dryer
- thermal gun
- soldering iron
- also another handy tool that any master can find.

Manufacturing

First you need to find all the necessary materials and be patient. It took me three days to work, including development and experiments. I advise you to test the device diagram first, and then assemble it. Be careful when working with reed switches, it is very easy to break the glass body when bending the legs. Using a plastic clamp, secure the reed switches with hot glue. The distance for them, select experimentally, it should ensure that the reed switches are triggered when the magnet passes. Seal the connection with heat shrink and hot melt glue or silicone. The finished bracelet is put on the clutch and allows the adjustment of the best actuation position. Also, it can be easily replaced in the event of a malfunction by disconnecting the plug. Find a moisture-resistant plug, with four or more legs. If the plug is exposed to moisture, cover it with heat shrink or silicone. You can do without it by soldering the wires directly.

Depending on the length of the float holder, the actuation stroke of the device depends. In my case, the length is about 40cm. The float profile must be heated with a construction hair dryer and laid on the coupling (this is done quickly), then glued and riveted. The resulting clamp should provide easy rotation relative to the reed switch coupling. The float itself, having installed the plugs, is simply attached to the profile with rivets. The fact that the design of the float has a certain flexibility will prevent further breakage. A non-uniform magnet is also attached to the structure, so that it is within the reed switch actuation distance. Having drilled holes in the coupling, install the float stopper, it is needed for the correct actuation position during the operation of the device.