Soil moisture detection and display circuit

Soil moisture detection and display circuit

Shown is a soil moisture detection and display circuit composed of a hygroscopic resistor . This circuit is mainly composed of humidity-sensitive resistor RS, humidity signal amplification circuit (ICI, RP1, RP2, R3~Rs, such as VD3), voltage-stabilized power supply circuit, etc. It can be used in forestry, agriculture and other departments to detect whether there is water shortage in the soil.     In the circuit, the humidity-sensitive resistor RS, amplification transistor vri, Ri, and R2 form a soil moisture detection circuit, which is used to detect changes in humidity in the soil and transmit the signal to the humidity signal amplification circuit. After the +12 V DC voltage is sent into the circuit, it is first divided by resistors 9-R11 , stabilized by the voltage stabilizing diode VD2, and then +6 V voltage is output. The +6 V voltage provides the working voltage for the ⑥ pin of Icl all the way, and the R7 is stepped down and VDI is stabilized to output a 2.5 V voltage to power the humidity detection circuit.