Humidity detection box control circuit in greenhouse

Humidity detection box control circuit in greenhouse

Shown is a temperature detection and control circuit in a greenhouse . There is a humidity detection sensor RS (humidity resistor) in the greenhouse
. When the humidity increases. The resistance value of RS will increase. When the humidity decreases, the resistance value will also decrease. After passing through the bridge rectifier circuit, the DC voltage will increase.
This will convert the humidity situation into a DC voltage and add it to the inverting input of the voltage comparator IC 2. end. That is, when the humidity is high, IC2 outputs a low level,
the transistor VT1 is cut off, and the humidifier does not operate. When the humidity is low, IC2 outputs a high level. VT1 is turned on; relay K acts to make the humidifier work
and increase the humidity in the shed. Three-terminal regulator IC 1 provides +12 V DC power to the circuit.