Reed Relays and
Electronics India Limited
Manufacturer of Reed Switches, Reed Sensors and Reed-based products
Reed Relays and Electronics India Limited Incorporated in 1971

Reed sensors in Telephone Handsets

Reed switches in telephone hook switches
Telephone Handset

Even though the telephone was ubiquitous in the 80s and 90s even every home or office, it has been replaced with cellular phones or smart phones. Offices though, still continue to use desktop telephones which use handsets and hook switches. This makes it easier for higher level management to get connected on external calls by their secretaries or receptionists as well as internally, via an intercom system, to a PBX or a private branch exchange.

These telephone appliances, make many calls a day and the handset is placed back on the base station when hanging up a call. To avoid static when using mechanical switches in the base station, handset designers use normally closed reed sensors on the base station, with a magnet on the handset. This also helps remove the noise of the handset being placed on the base station and the user at the other end always gets a silent ending to a call.

When the handset is taken off the base station, it closes the normally closed reed sensor and enables dialing circuit. In the case of wireless handsets, the same sensor is also used to trigger the charging circuits.

Application Classification

Applications are classified as Position Sensing, Pulse Counting, Electromagnetic or Relay, Temperature Sensing or Magnet Biasing types. This application is classified as follows and the link gives more information on best practices to help select the most suitable AT band and matching magnet.

Position sensing Type
Position sensing Position Sensing type application When an application requires the end position of a movement sensed, or the sensing of a part when it Continue reading ->

Nov 7, 2020

The Reed Switches and Sensors used in such applications need to be robust, durable and efficient in meeting a high life expectancy. Our engineers work hard in life testing our products under various conditions, and our intention is to ensure end product durability and life. Although we wouldn’t want to restrict any of our products for use in only certain applications, the recommended products for use in this application are listed below.

R5B Ultra-miniature Normally Closed SMD Reed Sensor
Ultra-miniature biased SMD R5B-S Reed Sensor DrawingR5B-S Reed Sensor Pad L:ayoutR5B Reed Sensor Carrier Tape starFeatures5W Contact Rating. Normally Closed Continue reading ->

Nov 30, 2020

R2B, Normally Closed, SMD Reed Sensor
Drawing of R2B-S NC Reed SensorR2B-S Gull-wing SMD Formed Reed Sensor Pad LayoutDrawing of R2B-F NC Reed SensorR2B-F Low Profile SMD Continue reading ->

Nov 30, 2020

IL-2022 Reed Switch for Inductive Loads
Reed Switch for Inductive Load This Inductive Load switching IL-2022 Reed Switch is designed for performance at moderate inductive loads of 15W. The flattened leads are Continue reading ->

Dec 3, 2020