RC-33 Magnetic Reed Switch Door Sensor Normally Open

From the shop's description

Description The magnetic switch sensor comes in a pair consisting of a Reed Switch and a magnet. The wired part of the module is the reed switch, whereas the other part is the magnet. It is commonly used as a home security alarm system. The sensor consists of two main parts, a magnet and as switch with terminals to connect the signal wires. The magnet mounts to a door or access panel, while the switch mounts to the frame. When the door is closed the two pieces should be in close contact of each other. When the door opens this distance increases, eventually toggling the switch. This allows to know when the door is open. Specifications: Product Name: Magnetic Door Switch Model: RC-33 Contact Type: NO (Normally Open) Actuation Distance: 18mm ± 5mm Max. Current: 0.5A NO means Normally Open: when the magnet separates, the circuit is conductive( light on ); When the magnet together, the circuit is not conductive ( light off ). Max. Contact Power: 10W Working Voltage: DC0-100V Each Size(Approx): 17 x 10.6mm Cable Length(Each): 30cm Material: ABS (Housing) Color: White. Package Content: Magnetic Door Switch. Connection The sensor can be easily connected to any chip with a microcontroller, e.g. an Arduino. By attaching a pulling up resistor or by running an internal pull-up, the read can be implemented in digital form.