Search results
Results from the WOW.Com Content Network
A relay Electromechanical relay principle Electromechanical relay schematic showing a control coil, four pairs of normally open and one pair of normally closed contacts An automotive-style miniature relay with the dust cover taken off. A relay is an electrically operated switch. It consists of a set of input terminals for a single or multiple ...
Electromechanical protective relays operate by either magnetic attraction, or magnetic induction. [9]: 14 Unlike switching type electromechanical relays with fixed and usually ill-defined operating voltage thresholds and operating times, protective relays have well-established, selectable, and adjustable time and current (or other operating parameter) operating characteristics.
High voltage interface relays, a.k.a., interface relays: [1] [2] or coupling relays or insulating interfaces [3] [4] is a special class of electrical relays designed to provide informational and electrical compatibility between functional components isolated from each other and not allowing for a direct connection due to a high difference of potentials.
This page was last edited on 28 November 2019, at 01:34 (UTC).; Text is available under the Creative Commons Attribution-ShareAlike 4.0 License; additional terms may apply.
(from top) Single-pole reed switch, four-pole reed switch and single-pole reed relay. Scale in centimeters. Reed switch, contact detail. Commonly-used circuit symbol Operation of the reed switch. The reed switch [i] is an electromechanical switch operated by an applied magnetic field.
Relay or contactor – Electro-mechanically operated switch (see also solid state relay above) Reed switch – Magnetically activated switch; Thermostat – Thermally activated switch; Humidistat – Humidity activated switch; Circuit breaker – Switch opened in response to excessive current: a resettable fuse
(from top) Single-pole reed switch, four-pole reed switch and single-pole reed relay. Scale in centimeters. A reed relay [i] 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.
A normal relay uses a wire coil and the mechanical movement of the metal contacts to switch the load on and off. The metal contacts may weld shut after repeated operation cycles. If this happens, the machine would continue running if the operator pressed the emergency stop pushbutton. This would be hazardous for the operator.