Reed Switch / Magnetic Contact KN-04C-BR by No name — cylindrical form, model KN-04C-BR

Cylindrical reed switch KN-04C-BR by No name is a compact magnetic contact designed to detect the presence or absence of a magnetic field. The sensor contains a sealed pair of ferromagnetic contacts that close or open under a magnetic influence, providing a passive contact output suitable for direct connection to alarm panels, control circuits and basic automation systems. Its cylindrical form factor and small dimensions make it suitable for installation in narrow frames, panels or housings where space is limited.

Advantages

The KN-04C-BR offers a passive, low-power switching function without the need for an independent power supply, ensuring simple electrical integration and minimal maintenance. Its sealed construction provides reliable contact operation and protection from dust and humidity in typical indoor environments. The cylindrical shape allows discreet installation and alignment with a matching magnet, and the mechanical design supports long-term switching cycles with stable performance.

Suitable for

• Door and window position monitoring in alarm systems
• Panel or enclosure tamper and access control
• Basic automation sensing where magnetic contact is required
• Retrofit installations in narrow frames or recessed mounting points

Key specifications

• Sensor type: normally open / normally closed magnetic reed contact (magnetic field actuated)
• Form factor: cylindrical, compact dimensions for recessed or narrow mounting
• Output: passive mechanical contact suitable for direct wiring to control panels
• Operating principle: magnet-actuated sealed reed contacts
• Environmental use: intended for indoor installations; sealed against dust and minor humidity (not rated for direct immersion)

How to use

Install the KN-04C-BR by positioning the cylindrical sensor and its matching magnet so that their relative movement corresponds to the monitored opening or closing action. Mount the sensor in the fixed frame or housing and place the magnet on the moving part (door, window, or panel) aligned along the sensor axis. Connect the two contact wires into the alarm panel or control circuit following the panel manufacturer’s wiring diagram for normally open or normally closed inputs. Test operation by moving the magnet toward and away from the sensor to confirm reliable contact change and correct panel response.

Usage recommendations

For reliable operation, ensure correct alignment between sensor and magnet and avoid mounting near strong external magnetic sources. Use appropriate wire routing and strain relief to protect connections; where exposure to moisture or outdoor conditions is expected, select a specifically rated enclosure or alternative sensor designed for harsh environments.