Two-position water level control for water tower

Abstract

The article is devoted to the description of the electrical circuit and the principle of operation of the water level regulator in the water tower tank. The executive body of the regulator, which directly turns on and off the electric pump unit of the water lifting system, is a magnetic starter, the coil of which is controlled in turn by an electronic key, the transfer of which to the closed state is carried out by applying a current signal to its low-resistance input from the control signal shaper, which has a hysteresis characteristic "input -exit". The shaper is made on discrete electronic elements: resistors, diodes and transistors. The regulator provides on-off level control according to the signals of level or pressure sensors of various operating principles, including electrode, float, electrocontact pressure gauges, and pressure switches. The organization of a double positive feedback in the regulator ensures a clear operation of the magnetic starter without “bounce”. At the same time, to transmit signals from sensors to the regulator, the number of wires of the communication line is reduced from two to one, which, taking into account the large distance of the water tower from the water source, increases the reliability of communication and reduces the cost of its construction. This is also facilitated by the fact that to control the input of the regulator from the sensors, alternating current signals of a relatively small value (up to 4 - 5 mA) are supplied, excluding their noticeable attenuation when transmitted over a distance of 2 or even more kilometers over small-section wires (1 – 1.5 mm2). At the same time, the electrochemical corrosion of the electrodes is also greatly reduced.