The MC-38 Wired Door/Window Sensor is a compact magnetic proximity switch used to monitor whether doors, windows, or drawers are open or closed. Technical Specifications

• Operating Voltage: Up to 100V DC
• Max Current: 0.5A (100mA recommended)
• Rated Power: 10W
• Sensing Distance: 15mm to 25mm
• Housing: Flame-retardant ABS plastic
• Wiring: Two-wire, non-polar cable

Switch Behavior (NC vs. NO)

• Normally Closed (NC – Most Common): Circuit is closed (connected) when the door is shut. Circuit opens (breaks) when the door opens.
• Normally Open (NO): Circuit is open (broken) when the door is shut. Circuit closes (connects) when the door opens.

Working PrincipleThe sensor consists of two separate pieces:

1. The Magnet: A passive, unwired piece mounted to the moving door or window.
2. The Reed Switch: A wired piece mounted to the stationary frame. When the magnet gets close, its magnetic field pulls internal metal contacts together to change the electrical state.

Quick Installation

• Mounting: Use the pre-applied double-sided tape or screws.
• Alignment: Mount pieces parallel to each other. Keep the gap under 15mm when closed.
• Testing: Use a multimeter in continuity mode to confirm the switch opens and closes as the magnet moves.