Anti-condensation automatic exhaust and bird chirping sound circuit for greenhouse or greenhouse

The circuit is shown in the figure. It consists of a resistive dew sensor, an electronic switch, a relay-controlled exhaust fan circuit, a birdsong sound circuit, an audio power amplifier circuit and an AC step-down rectifier circuit. RH is a resistive condensation sensor that is particularly sensitive to high humidity air and can detect whether water vapor in the air will condense.