Motor
Panel is an example of a power drive system. Strowger or crossbar systems, in contrast, use individual electromagnets for operation: the power available from an electromagnet limits the maximum size of the switch element it can move. Panel having no such restriction, the dimensions of the panel were determined solely by the needs of the switch and the design of the exchange, as the driving electric motor can be made as large as is necessary to move the switch elements. Thus, most calls required only about half as many stages as in earlier and later systems. Motors used on Panel frames operated on A.C. or D.C. however they could only be started on D.C. In the event of an A.C. power failure the motor would switch over to its D.C. windings.
Read more about this topic: Panel Switch
Famous quotes containing the word motor:
“This biplane is the shape of human flight.
Its name might better be First Motor Kite.”
—Robert Frost (1874–1963)
“We disparage reason.
But all the time it’s what we’re most concerned with.
There’s will as motor and there’s will as brakes.
Reason is, I suppose, the steering gear.”
—Robert Frost (1874–1963)
“What shall we do with country quiet now?
A motor drones insanely in the blue
Like a bad bird in a dream.”
—Babette Deutsch (1895–1982)