The heat of summer. In the sky - no clouds. Without watering a vegetable garden is not to save. In this case good use of the installation, which pours itself. The device is an electronic relay on the VT1 transistor, the base and the emitter of which is connected to plates of conductive material embedded in the soil at a distance of 3 3.5 cm from each other. Because raw land is of low resistance, can assume that the base of the transistor is connected with its emitter (the transistor is turned off). But as soon as the soil begins to dry out, semiconductor the device is opened, actuates solenoid relay K1 and its contact pair a short circuit actuating mechanism of the electromagnet, lifting the flap water tank irrigation.
An electromagnet is a solenoid with a sucking action. Coil form made from phenolic resin or hard rubber, has a length of 100 mm, outer diameter 30 mm / internal 20 mm "Cheeks" diameter 70 and a thickness of 5 mm made of the same material as the frame, and stuck to it with glue BF-2 or "Moment".
Solenoid coil contains 4300 turns of wire sew 0,4 (for voltage 127 In) or 5500 turns sew 0,35 (for 220V). The core is made of mild steel (steel 10 or 20) with a diameter of 20 and a length of 100 mm. attached To the core pin, the length of which depends on the distance between the solenoid and the valve of the tank. Spring - pushing; its purpose is to at the end of the irrigation return valve in original state.
At the opposite end of the coil is inserted, a fixed core diameter and 20 length of 18 mm to enhance the pulling power of the solenoid. The stationary core made of the same material as that of the mobile.
A circuit diagram of a watering machine
The solenoid control valve: 1 - the stationary core; 2 - frame coil; 3 - winding; 4 - washer; 5 - spring; 6 - movable core
The device and the dimensions of the damper are not given, since they depend on tank and pipes. The main thing is that the mass of the damper does not exceed 300 - 350 g
In a sprinkler installation, you can use any electromagnetic relay (for example, PCM-1, RES-10), triggered at a voltage of 7 to 9 V. the Transistor type MP39 - MP42. Power - one battery "Corundum" or two series United sources L.
Author: Dmitry Kryazhev