Product description: SPDT magnetic door/window opening sensor - reed switch - Littelfuse 59140-3-S-02-A
The Littelfuse 59140-3-S-02-A reed switch is a wired magnetic sensor that uses contactless technology to detect the presence of a magnet. Designed for various applications, including determining the position of doors and windows. Thanks to its hermetically sealed housing and high IP67 protection level, it is resistant to dust, moisture and other unfavorable weather conditions. The 11.6 mm reach and SPDT contact configuration enable precise and reliable circuit switching. This sensor measures 23 x 14 x 6 mm , making it ideal for installation in confined spaces. It can be used in various applications such as industrial automation, security systems, access control and household appliances. The use of this sensor eliminates the need to use moving mechanical elements, which increases the reliability and durability of the system. The sensor requires an actuator , which must be ordered separately .
Magnetic door/window opening sensor - reed switch - Littelfuse 59140-3-S-02-A.
The contract is intended for various applications, including determining the position of doors and windows.
The principle of operation of a reed switch
A reed switch is a type of magnetic switch that operates based on the presence of a magnetic field. Inside the reed switch there are movable contacts made of ferromagnetic material. In the rest state, the contacts are normally open (NO) , which means that the circuit is open . Bringing the magnet closer closes the contacts and creates a short circuit, which is detected by the connected device. The reed switch housing is hermetically closed , which provides protection against weather conditions. Hysteresis in ferromagnetics requires the magnet to be moved a greater distance to disconnect the contacts. This makes reed switches ideal for applications requiring contactless switching , such as door opening sensors, alarm systems or revolution counters.
Connecting the reed switch to devices such as Arduino or Raspberry Pi
Connecting the Littelfuse 59140-3-S-02-A reed switch to an Arduino or Raspberry Pi is a simple process that allows it to detect the presence of a magnet. To connect the reed switch, connect one wire to the GND pin (ground) and the other wire to any digital input pin of the Arduino or GPIO of the Raspberry Pi. Then in the code set this pin as an input with activation of the internal pull-up resistor. The reed switch, when activated by the magnet, will complete the circuit, changing the logic state on the input pin.
Example of connecting a magnetic sensor with Arduino.
For proper operation of the sensor, the contractor requires an actuator, which must be ordered separately.
Technical specifications of the sensor
- Sensor type: reed switch
- Range: 11.6 mm
- Switchable power: 5W
- Connection: 0.3 m cable
- Contact configuration: SPDT
- Switching current: 0.25 A
- Switching voltage: max. 175 V
- Operating temperature: from -40°C to 105°C
- Housing material: 20% GF PBT, black, epoxy seal
- Features: actuator ordered separately
- Collaborating articles: 57140-000
- External dimensions: 23 x 14 x 6 mm
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