SU596192A2 - Automatic watering control device - Google Patents

Description

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 The invention relates to agriculture, namely, to devices for automatic control of irrigation and can be used to automatically control the salinity and moisture content of the soil during programmed cultivation of crops in open and closed ground.

According to the main author. St. No. 463427 a device for automatic irrigation control is known, which contains soil moisture content sensors associated with control equipment made in the form of two paired transistors connected to a potentiometer bridge circuit, one of which is covered with a hygroscopic cord lowered into the soil to the lowest point of the root system. plants.

The device works on the principle of temperature difference, which excludes the influence of the salt content of the soil on its readings.

The purpose of the invention is to provide automatic control of soil removal during irrigation.

This is achieved in that the device is equipped with a soil salt-moisture content sensor, an operational amplifier with inverting and non-inverting inputs, an output amplifier, and a comparison unit with a setpoint device. With

In this way, the output of the soil moisture content sensors is connected to the inverting input of the operational amplifier, to the non-inverting input of which the salt-moisture content sensor is connected

soil, and the output of the same amplifier through the output amplifier is connected to the unit of comparison with the setpoint device.

FIG. 1 shows the proposed device with sensors, general view; in fig. 2 - the sensor connection circuit is functional.

The automatic irrigation control device contains a soil moisture content sensor 1 with control equipment, a soil moisture content sensor 2, an operational amplifier 3 with an inverting input 4 and a non-inverting input 5, an output amplifier 6, a comparison unit 7, a setting device 8, a recording device 9, a power amplifier 10, an executive mechanism 11, sprinkler activation unit 12 and metering-displacing device 13.

The device works as follows. In the soil (see Fig. 1), sensors 1 of soil moisture content and sensor salt content of soil 2 are installed. When the marginal field moisture capacity reaches 70% or less, sensors 1 produce a potential difference,

which in the paired transistor circuit changes in direct proportion to the temperature of the various soil layers. As a result, the signal is fed to the switching unit of the sprinkler unit 12. At the same time, the signal is fed to the inserting input 4 of the operating amplifier 3, which performs the function of the first comparing device. During the irrigation process, the concentration of salt content in the soil is disturbed, i.e., leaching, removal and filtration of mineral fertilizers that feed the plants. As a result of disturbing the salt concentration in the soil, the soil moisture content sensor sends a signal to the non-inverting input 5 of the operational amplifier 3. By comparing and subtracting the signals from the two sensors, a difference signal is obtained equivalent to the salt content, reduced to a unit volume of the salt solution concentration. Next, the difference signal from the output of the operational amplifier 3 is fed to the output amplifier 6, simultaneously to the recording devices 9 and the comparison unit 7. The signal in the comparison unit

7 is compared with a predetermined salinity in the setter 8. When the salinity of the soil corresponds to the predetermined value, the output signals of the transmitter 8 and. output amplifier 6 are equal to each other in amplitude and opposite in phase. In this case, the output of Comparison Block 7 is zero.

There are 8 cases when the salt content in the soil is less than the specified value, the setpoint signal 8 is greater than the output amplifier 6 signal, and a control signal appears on the comparison unit 7, which is fed to the amplifier

 POWER 10 and actuator 1, which acts on the dosing-mixing device 3.

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Thus, in the process of irrigating the soil, salt-like mineral fertilizers are introduced into it. A concentrated solution of nitrogen-phosphorus-potassium fertilizers will be automatically fed into the irrigation pipelines until the soil, soil, soil reaches a predetermined value. In a similar way, mineral fertilizers are automatically applied when precipitation falls.

The proposed device allows the process of automatic mineral fertilization in the soil during the irrigation process.

Claims (1)

1. Copyright certificate № 463427, cl. A 01 G 27/00, 1972.