Editing Relay (section)

=== Reed relay ===
[[file:Reedrelay.jpg|thumb|(from top) Single-pole reed switch, four-pole reed switch and single-pole reed relay. Scale in centimeters]]

A [[reed relay]] is a [[reed switch]] enclosed in a solenoid. The switch has a set of contacts inside an [[Vacuum|evacuated]] or [[inert gas]]-filled glass tube that protects the contacts against atmospheric [[corrosion]]; the contacts are made of [[magnet]]ic material that makes them move under the influence of the field of the enclosing solenoid or an external magnet.

Reed relays can switch faster than larger relays and require very little power from the control circuit. However, they have relatively low switching current and voltage ratings. Though rare, the reeds can become magnetized over time, which makes them stick "on", even when no current is present; changing the orientation of the reeds or [[degaussing]] the switch with respect to the solenoid's magnetic field can resolve this problem.

Sealed contacts with mercury-wetted contacts have longer operating lives and less contact chatter than any other kind of relay.<ref name="keller">{{cite journal |last1=Keller |first1=A.C. |date=January 1964 |title=Recent Developments in Bell System Relays — Particularly Sealed Contact and Miniature Relays |url=https://archive.org/details/bstj43-1-15 |journal=The Bell System Technical Journal |volume=43 |issue=1 |pages=15–44 |doi=10.1002/j.1538-7305.1964.tb04057.x |access-date=2023-03-16}}</ref>