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
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Reed Relay

A Reed Relay is a type of Relay that uses a Reed Switch within a coil. Coils can be designed to accommodate multiple Reed Switches for designing multi-pole Reed Relays. A normally open reed switch can be biased closed with a permanent magnet or with a biasing coil to produce a normally closed reed relay, but frequently a changeover reed is used for normally closed relays.

Reed_relay (Wikipedia)
(from top) Single-pole reed switch, four-pole reed switch and single-pole reed relay. Scale in centimeters.

A reed relay is a type of relay that uses an electromagnet to control one or more reed switches. The contacts are of magnetic material and the electromagnet acts directly on them without requiring an armature to move them. Sealed in a long, narrow glass tube, the contacts are protected from corrosion. The glass envelope may contain multiple reed switches or multiple reed switches can be inserted into a single bobbin and actuate simultaneously. Reed switches have been manufactured since the 1930s.

Compared with armature-based relays, reed relays can switch much faster, as the moving parts are small and lightweight, although switch bounce is still present. Also, they require less operating power and have lower contact capacitance. Their current handling capacity is limited but, with appropriate contact materials, they are suitable for "dry" switching applications. They are mechanically simple, making for reliability and long life.

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