Seco-Larm SL-SM200QW Normally Closed Proximity Door Switch, Package of 5
This Normally Closed Proximity Door Switch is built to monitor the opening and closing state of windows and doors. The internal reed switch is closed, meaning the circuit is completed, when the magnet is near the sensor, meaning the door or window is closed.
* Please note these switches cannot carry current. A supplementary relay with surge protection must be used if the intention of the switch is to activate a bell or siren strobe.
Normally Closed vs Normally Open
Normally open *Example: light turns on when door is open A N/O contact does not flow current in its normal state. Activating the contact (opening a door/window) will create a flow of current to create an alarm/turn on light etc.
Normally closed*Example: light is on when door is closed A N/C contact flows current in its normal state. Activating the contact (opening a window/door) will interrupt the contact, allowing no current to flow. Normally closed is typically used for alarm systems to alert when door/window is opened or wire is cut.
Door Switch Specifications
- Dimensions: 2.5" x 0.75" x 0.5" (part with screw terminals) 2.5" x 0.75" x 0.625" (part with magnet)
- Contacts: Closed when Door is Closed and Open when Door is Open
Door Switch Includes
- 5 x SL-SM200QW Magnetic Reed Door Switch Kit
Door Switch Support
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