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AC contactor for pump application. A contactor is an electrically controlled switch used for switching an electrical power circuit. [1] A contactor is typically controlled by a circuit which has a much lower power level than the switched circuit, such as a 24-volt coil electromagnet controlling a 230-volt motor switch.
They are used as high-current switches or contactors, where contact erosion from constant cycling would be a problem for conventional relay contacts. Owing to environmental considerations about the toxicity of mercury, mercury relays are mostly obsolete, though modern encapsulated units still have applications.
Artist's impression of Leonardo's method for neutralizing the refractive power of the cornea. Leonardo da Vinci is frequently credited with introducing the idea of contact lenses in his 1508 Codex of the eye, Manual D, [9] wherein he described a method of directly altering corneal power by either submerging the head in a bowl of water or wearing a water-filled glass hemisphere over the eye.
An electromagnetic relay with a pair of contacts. An electrical contact is an electrical circuit component found in electrical switches, relays, connectors and circuit breakers. [1]
By measuring this zone, the autorefractor can determine when a patient's eye properly focuses an image. The instrument changes its magnification until the image comes into focus. The process is repeated in at least three meridians of the eye and the autorefractor calculates the refraction of the eye, sphere, cylinder and axis.
AC relay with shading coil (red arrow near top) for operating with AC. A shading coil or shading ring (Also called Frager spire or Frager coil) is one or more turns of electrical conductor (usually copper or aluminum) located in the face of the magnet assembly or armature of an alternating current solenoid.
Arc suppression is an area of interest in engineering due to the destructive effects of the electrical arc to electromechanical power switches, relays and contactors' points of contact. [11] There are many forms of "arc suppression" that provide contact protection in applications operating at less than 1 Ampere. Most of these, however, are more ...
Every time the contacts of an electromechanical switch, relay or contactor are opened or closed, there is a certain amount of contact wear. If the contact is cycling without electricity (dry), the impact of the contact electrodes a slightly deformed by the resulting cold forging. [1]