set2: 1 x humidity sensor with humidity sensitive resistor + 1 x Battery Undervoltage Control Board Measurement of humidity, humidity sensor, humidity detection, with a relay output, direct power control equipment using high-quality HR202 humidity sensor; the comparator output directly drive the relay, the 220V AC or other equipment; with a potentiometer to adjust temperature detection threshold sensor interface can be arranged needle, with the lead of humidity sensor; Type: Electronic products Model Number: 12V Charging Controller Protection Board Application: Computer Operating Temperature: -40-+85 Supply Voltage: 12V Electronic products: For Arduino STM Battery Undervoltage Control Board Size:40x29mm The circuit board size: 50x26mm, thickness 19mm, with four 3mm fixing bolt holes, easy to install Contact normally open circuit connection: Contact normally closed circuit connection: Functional diagram connection is when the relay does not suck timely public side and normally closed terminal is turned on, the equivalent of the switch is closed, the circuit is turned on, the device has power to work, when the relay pulls in, the equivalent of switching off the device no electricity does not work Electrical parameters: Power supply voltage: 5VDC (default: 5V ) currents: greater than 150mA The maximum load: 250V 10A AC or 30V 10A DC, less than this power can be used Colour:blue Material:PCB/plastic humidity sensor Size:50 x 26mm Package Contents: 1 x humidity sensor with humidity sensitive resistor 1 x Battery Undervoltage Control Board