The synchro is a type of rotary electrical transformer that is used for measuring the angle of a rotating machine such as an antenna platform. The primary winding of the transformer, fixed to the rotor, is excited by a sinusoidal electric current, which by electromagnetic induction causes currents to flow in three star-connected secondary windings fixed at 120 degrees to each other on the stator. The relative magnitudes of secondary currents are measured and used to determine the angle of the rotor relative to the stator, or the currents can be used to directly drive an electric motor that will rotate in unison with the synchro. In the latter case, the whole device is also called a selsyn (a word made up from self-synchronizing).
The synchro was developed during World War II as part of a servomechanism that was used to synchronise the movement of a gun turret to a control dial.
Synchros designed for terrestrial use tend to be driven at 60 hertz (the mainsfrequency in many countries), while those for marine or aeronautical use tend to operate at 400 hertz (the frequency of the on-board generator driven by the engines).
Synchros designed for terrestrial use tend to be driven at 50 or 60 hertz (the mainsfrequency in most countries), while those for marine or aeronautical use tend to operate at 400 hertz (the frequency of the on-board generator driven by the engines).
Selsyn motors were widely used in motion picture equipment to synchronize movie cameras and sound recording equipment, before the advent of crystal oscillators and microelectronics.
These three are bussed to the other selsyns in the system, and provide the power and information to precisely align by rotation all the shafts in the receivers.
Share your thoughts, questions and commentary here
Want to know more? Search encyclopedia, statistics and forums:
Press Releases |
The Wikipedia article included on this page is licensed under the
Images may be subject to relevant owners' copyright.
All other elements are (c) copyright NationMaster.com 2003-5. All Rights Reserved.
Usage implies agreement with terms, 1022, m