Skip to content
#1 Source in low voltage wire and cable. Call us today to learn more about special offers.

Magnetic Reed Switches

Magnetic Reed Contact Switches

Often the first line of defense in a security system, the magnetic door switch is a mechanism recessed in door and window frames. It’s made to trigger alarm and surveillance systems when unauthorized intrusion is detected. Our magnetic contact switches utilize the power of rare earth magnets to create an open or closed loop circuit.

The recessed magnetic switch is most common in residential purposes as it’s concealed and mounted within the materials of the structure. The recessed magnetic door switch is made with the same magnetic reed switch used for surface-mount alarm contacts. Instead of a rectangular housing, recessed alarm contacts have a cylindrical case. This makes them easy to install by simply drilling a hole. The magnets are also made using the same type of round housing.

How a Magnetic Reed Switch Works

The magnetic reed switch is typically installed on the door frame and the magnet that activates the switch is typically installed on the door. Inside the magnetic reed switch, a thin piece of steel – a steel ‘reed’, if you will – is held in position by the attraction of the magnet when the door is closed. When the door is opened, the magnet is taken away from the switch and the spring tension of the “reed” causes it to spring back against the other contact, changing the state of the switch.

Closed Loop, Open Loop Vs. SPDT

Most magnetic reed switches are closed loop, or the switch is closed in its default state. When a magnetic reed switch is designed so that the magnet is close to the switch in its default state, it is considered an open loop style. Another variation is the SPDT, or Single Pole Double Throw magnetic reed switch.

It has both open and closed loops incorporated into its design. Finally, the DPDT, or Double Pole Double Throw has two SPDT reeds in the same contact switch housing, with each having its own common open and closed side.

A popular magnetic switch set Primus Cableoffers is the Reed Switch Set, Closed Loop, Steel Door Recessed 3/4" Magnetic Switch w/ Screw Terminals - 10 Pack. This closed loop magnetic reed switch set is 3/4” recessed with screw terminals. It comes hermetically sealed with plated contacts to resist sticking or freezing. It is available in 1/2” standard gap and 3/4"+ wide gap versions. Its short length and composition of PC board type terminals makes installation quick without soldering.

Primus Cable provides end-to-end security system solutions besides magnetic switches. Our products are manufactured of quality build materials and offered at the most competitive prices. Thank you for visiting our website.

Order from Primus Cable, and upgrade your home or business security system today!

If you have any questions, feel free to give us a call. 
  • Commercial Overhead Door Switch
    from Call for Pricing

    Commercial Overhead Door Surface Mount Switch Set - 4110/4482 Series

    4482A
    GRI

    These products are all Made to Order Which means they are non-cancelable and non-refundable Description Commercial Overhead Door Surface Mount...

    View full details
    from Call for Pricing
  • Water Sensor With Relay Contact - 2500/2600 Series
    from $21.80

    Water Sensor With Relay Contact - 2500/2600 Series

    2600
    GRI

    These products are all Made to Order Which means they are non-cancelable and non-refundable Description Water Sensor With Relay Contact Undete...

    View full details
    from $21.80
  • Miniature Surface Mount Switch Sets - 1100 Series - 10 Pack
    from $53.00

    Miniature Surface Mount Switch Sets - 1100 Series - 10 Pack

    1100A-12
    GRI

    These products are all Made to Order Which means they are non-cancelable and non-refundable Description Miniature Surface Mount Switch Sets - ...

    View full details
    from $53.00
  • Miniature 1/4” Recessed Switch Set - 50R Series - 10 Pack
    from $32.80

    Miniature 1/4” Recessed Switch Set - 50R Series - 10 Pack

    50RF-12
    GRI

    These products are all Made to Order Which means they are non-cancelable and non-refundable Description Miniature 1/4” Recessed Switch Set -...

    View full details
    from $32.80
  • Capped Miniature Surface Mount Switch Set - 700 Series - 10 Pack
    from $63.60

    Capped Miniature Surface Mount Switch Set - 700 Series - 10 Pack

    700CL-12
    GRI

    These products are all Made to Order Which means they are non-cancelable and non-refundable Description Capped Miniature Surface Mount Switch ...

    View full details
    from $63.60
  • Adjustable Screw Plunger/Push Button Switch, Closed Loop 3/8" Press Fit w/ Screw Terminals
    $47.20

    Press Fit Reed Switch Adjustable Screw Plunger/Push Button Switch, Closed Loop, 3/8" w/ Screw Terminals - 10 Pack

    AL-GRI-3020-WH
    GRI

    These products are all Made to Order Which means they are non-cancelable and non-refundable Description Press Fit Reed Switch Adjustable Scr...

    View full details
    $47.20
  • Standard Surface Mount Switch Sets - 29P Series  - 10 Pack
    from $64.20

    Standard Surface Mount Switch Sets - 29P Series - 10 Pack

    29PA-12
    GRI

    These products are all Made to Order Which means they are non-cancelable and non-refundable Description Standard Surface Mount Switch Sets - 2...

    View full details
    from $64.20
  • Tamper Proof Miniature Surface Mount Switch Set w/ Concealed Terminals
    from $56.40

    Miniature Surface Mount Switch Set - 129 Series - 10 Pack

    129A
    GRI

    These products are all Made to Order Which means they are non-cancelable and non-refundable Description Miniature Surface Mount Switch Set - 1...

    View full details
    from $56.40
  • Under Carpet Water Sensor with Relay Contact and Automatic Reset
    from $29.84

    Surface Mount Water Sensor - 2500T/26000T Series

    2600T
    GRI

    These products are all Made to Order Which means they are non-cancelable and non-refundable Description Water Sensor (Under Carpet) with Relay...

    View full details
    from $29.84
  • Reed Switch Set, Closed Loop
    from $42.20

    Super Miniature Surface Mount Switch Sets - 505 Series - 10 Pack

    505-12
    GRI

    These products are all Made to Order Which means they are non-cancelable and non-refundable Description Super Miniature Surface Mount Switch S...

    View full details
    from $42.20