• Normally Closed (NC) Magnetic Contact
• Recessed Hidden Installation Design
• Reliable Magnetic Reed Switch Technology
• Durable ABS Plastic Housing
• Designed for Alarm & Security Systems
• Suitable for Doors & Windows
The DH-33 Recessed Door Contact Sensor (NC) is a wired magnetic sensor designed for alarm and security systems to detect door or window openings.
The sensor works using a magnetic reed switch and magnet pair. When the door is closed, the magnet keeps the circuit closed. When the door opens and the magnet moves away, the circuit opens and sends a signal to the alarm system.
Its recessed design allows installation inside the door or window frame, making the sensor hidden and more secure compared to surface-mount sensors.
The DH-33 sensor is widely used in home security systems, burglar alarms, access control systems, and commercial security installations where reliable intrusion detection is required.
Product Type: Recessed Magnetic Door Contact Sensor
Model: DH-33
Contact Type: NC (Normally Closed)
Operating Voltage: Up to 100V DC/AC
Max Switching Current: 0.5A
Max Power Load: 10W
Detection Gap: Approx. 10 mm
Material: ABS Plastic
Connection Type: Wired
Installation Type: Recessed / Flush Mount
Color: White
Application: Alarm & Security Systems
Home Security Systems
Burglar Alarm Systems
Office Doors
Window Security
Warehouses
Commercial Buildings
Access Control Systems
Smart Alarm Installations
Q1: What does NC mean in door contact sensors?
NC means Normally Closed — the circuit remains closed when the door is shut.
Q2: What is a recessed door contact sensor?
It is installed inside the door frame so the sensor remains hidden.
Q3: Can it be used on windows?
Yes, it works for both doors and windows.
Q4: Is it compatible with alarm systems?
Yes, it works with most wired burglar alarm panels.
Q5: Does it require power?
No, it only sends a switching signal to the alarm system.
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