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1938 - C.R. Hanna adjusts the magnet control of his latest invention, the Silverstat

SILVER BUTTONS AT WORK

CD 2478056 E&MP12.035

Electric Appliances & Apparatus

Oct. 12 1938

C. R. Hanna, research engineer of the Westinghouse Electric & Manufacturing Company, adjusts the magnet control of his latest invention -- the "Silverstat" which utilizes silver buttons and a "tug-of-war" to regulate voltages automatically.

additional text found...

TINY ELECTRICAL DEVICE CONTROLS VOLTAGE OUTPUT OF INDUSTRIAL GENERATORS

A new compact voltage regulator for industrial electrical generators has been announced here by its inventor, Hanna of the Westinghouse Research Laboratories. The device is designed for plants producing their own power.

The device keeps independent generators giving power at constant voltage, regardless of the load on the power line in the installation.

Ordinarily such generators have the human-like trick of lagging at their work when heavily loaded. They also produce too much voltage when the power load, drawn from them, is light.

One past method of overcoming this difficulty was to have a man regulate the generator's output by hand control of rheostats.

The new device consists of a number of graduated electrical resistances which can decrease or increase the generator's speed, and hence its power output.

The selection of these resistances is effected automatically.

Its name is the Silverstat, because the electrical contacts of the resistances consist of tiny silver buttons.  


Original Caption by Science Service
Westinghouse



National Museum of American History

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