Magnetic latching relays require one pulse of coil power to move their contacts in one direction, and another, redirected pulse to move them back.
12.
In computer memories, latching relays and other relays were replaced by delay line memory, which in turn was replaced by a series of ever-faster and ever-smaller memory technologies.
13.
Such an electrically latching reed relay requires continuous power to maintain state, unlike magnetically latching relays, such as ferreed ( ferrite and reed relay ) or the later remreed ( remanent reed relay ).
14.
It typically has better thermal stability than a BJT . Because they are controlled by gate charge, once the gate is closed or opened, there is no additional power draw, as there would be with a bipolar junction transistor or with non-latching relays in some states.
15.
The computer controlled the magnetic latching relays by Signal Distributors ( SD ) packaged in the Universal Trunk frames, Junctor frames, or in Miscellaneous Trunk frames, according to which they were numbered as USD, JSD or MSD . SD were originally contact trees of 30-contact wire spring relays, each driven by a flipflop.
16.
The 219 packaged family of products, and the 219NE ( Nuclear Energy ) family, encompassed in addition to the standard electro-mechanical versions-the 236 / 237 / 238 family of industrial time-delay relays, the later 246 / 247 / 248 family of advanced time-delay relays, the 255 Series of latching relays, the 311 Series of Sequence / stepper relays, the 349 Series Voltage Sensors and the RSX Series of custom packages controls.
