This Product Selection Guide contains information to help select products in the Magnetic, Reed Switches category on DigiKey.com
Magnetic reed switches are devices consisting of a pair of ferromagnetic flexible metal reed contacts in a hermetically sealed glass, magnetosphere, or other molded body and are operated by an applied magnetic field. The contacts are normally open, closing when a magnetic field is present, or closed and open when a magnetic field is applied. The switch may be actuated by an electromagnetic coil or permanent magnet placed near the switch. When the magnetic field is removed, the reeds return to their original position. Contact forms include SPDT and SPST.
SelectionCharacteristics
Type: Refers to the different physical construction options available for the switches.
Circuit: Describes device function in terms of a number of poles and throws, as is typical for mechanical switches. For more information please see: Switch Basics, Examples of Pole and Throw
Operate Range: An indication of the magnetic field strength or target proximity required to actuate a switch, measured under manufacturer-defined conditions.
Release Range: Indicates the level to which an actuating influence must be reduced to allow an actuated switch to return to its resting state, as characterized by the manufacturer.
Current - Switching: The maximum current the switch is rated to interrupt.
Voltage - Switching AC: The maximum AC RMS (sine wave) voltage that a device is rated to interrupt, usually specified under conditions of minimal load current and a non-reactive load.
Voltage - Switching DC: The maximum DC voltage that a device is rated to interrupt, usually specified under conditions of minimal load current and a non-reactive load.
Power-Rated: Characterizes the switching capacity of a device’s contacts; the maximum allowable product of switching voltage and switching current to which a device should be subjected.
Operate Time: Characterizes the time delay between the application of rated coil voltage and the closure (or opening) of all contacts that occurs as a result. Typically does not include contact bounce time.
Release Time: Characterizes the time delay between the removal of power from the device coil and all contacts returning to their rest positions. Does not include bounce time, and may be affected by the choice of control circuitry.
Mounting Type: Indicates how the device is attached.
Termination Style: Selection of termination style used to connect the device to a system, such as axial, PC pins, or wire leads.
Length - Overall: Refers to the total length of the switch.
Size - Body: The nominal dimensions of the encapsulated portion of a switch, not including protrusions of device leads/contacts.
Height Above Board: Indicates how far the device will extend above the surface to which it has been attached.
Operating Temperature: Recommended operating temperature, typically given in a range or as a maximum. Exceeding these temperatures may affect performance or damage the device and other system components.
Capacitance: Refers to the inherent electrical capacitance that exists between the switch contacts.
Current - Carry: Indicates maximum allowable current flow through closed and settled (non-switching) contacts.
ProductExamples
| MFR PART # | DRS-DTH-45-50 |
|---|---|
| DIGIKEY PART # | F10259-ND |
| MANUFACTURER | Littelfuse Inc. |
| DESCRIPTION | Glass Body Reed Switch SPDT 45 ~ 50AT Operate Range 30W 350mA (AC), 500mA (DC) 350 V Through Hole |
| DATASHEET | Click Here |
| MFR PART # | ORD 213S-1/10-15 AT |
|---|---|
| DIGIKEY PART # | 374-ORD213S-1/10-15AT-ND |
| MANUFACTURER | Standex-Meder Electronics |
| DESCRIPTION | Glass Body Reed Switch SPST-NO 10 ~ 15AT Operate Range 1VA 100mA (AC/DC) 24 V Surface Mount |
| DATASHEET | Click Here |
| MFR PART # | PMC-1001THY |
|---|---|
| DIGIKEY PART # | 2010-1282-2-ND - Tape & Reel (TR) |
| MANUFACTURER | PIC GmbH |
| DESCRIPTION | Molded Body Reed Switch SPST-NC 10 ~ 50AT Operate Range 10W 700mA (AC/DC) 130 V Surface Mount |
| DATASHEET | Click Here |
MediaLinks
Videos
Standex Electronics Leads the Way in Reed Switch Technology
Gauss vs. AT – Operate & Release Distance – Coto Technology’s RedRock®
Articles
Micromachined Reed Switches Offer New Solutions to Many MEMS Applications
Liquid Level Sensors for Industrial Applications
Product Training Modules
Reed Switch Technology - Standex
Reed Switch Magnet Interaction - Standex
Reed Switch Basics - Littelfuse
Reed Switch Basics - Coto
Surface Mount Reed Sensors Overview - Standex
Latching FormB Reed Relays Overview - Standex
TechForum
Why is My Reed Switch Failing?
Switching Current vs. Carry Current in a Reed Switch?
Ampere Turn (AT) Spec in Reed Switches