Description
The MC-33 is a recessed (hidden) magnetic contact sensor designed for discreet door and window intrusion detection in wired alarm and access control systems. Unlike surface-mount contacts that sit visibly on the frame, the MC-33 installs flush into a drilled hole, making it nearly invisible once fitted—an important advantage for residential and commercial security where aesthetics and tamper resistance matter. As a Normally Closed (NC) sensor, the reed switch circuit remains closed (conductive) when the magnet is within close proximity (typically less than 5mm for this model), meaning the alarm loop is intact when the door or window is secured . When the door opens and the magnet separates from the switch, the circuit opens, triggering the alarm panel or microcontroller to register an intrusion. This fail-safe wiring convention is standard in security systems: a cut wire or tampered sensor also breaks the circuit and triggers an alert. The sensor consists of two components—the reed switch body and a matching permanent magnet—both designed for recessed installation into wooden or non-ferrous frames. It requires no external power and functions as a passive switch, connecting directly to an alarm panel’s zone input or a microcontroller GPIO pin with a pull-up resistor.
Features
-
Recessed Hidden Installation: Flush-mount design conceals the sensor inside the door or window frame, preserving aesthetics and reducing tamper visibility
-
Normally Closed (NC) Fail-Safe Wiring: Circuit remains closed when the door is secure; a broken wire or removed sensor also triggers an alarm—critical for security applications
-
Passive, Power-Free Operation: No battery or external power required; the reed switch actuates solely through the magnet’s proximity
-
Compact Recessed Profile: Miniature cylindrical housing designed to fit into a standard drilled hole (approximately 19mm hole size for some variants)
-
Metal-Shielded ABS Construction: Fire-resistant housing with metal shielding for stable performance and durability
-
Wired Connection for Alarm Panels: Screw terminals or pre-attached wire leads connect directly to wired alarm zone inputs
-
Wide Compatibility: Suitable for wooden doors, windows, cabinets, and access control systems in residential and commercial installations
Technical Specifications
| Parameter | Specification |
|---|---|
| Model | MC-33 (also listed as MC-33C) |
| Contact Type | Normally Closed (NC) |
| Switch Element | Magnetic Reed Switch |
| Housing Material | Fire-resistant ABS with metal shielding |
| Activation Distance | Typically <5mm (close proximity required for closed state) ; other sources list 15–25mm |
| Rated Current | 300mA ; some variants up to 500mA |
| Rated Voltage | Up to 100V DC |
| Rated Power | 10W |
| Installation Type | Recessed / Hidden (drill-mounted) |
Reviews
There are no reviews yet.