Page:Popular Science Monthly Volume 92.djvu/42

 Clap! Let There Be Light

Ey clapping your hands you can light up the whole house. No, there is no microphone to hear the sound

��SUPPOSE that you wished to light the electric light in the library while you were in the living-room and that you could do so by the clap of your hands. Or, on coming home at night, sup- pose that you

Armature Stop Pendulum^ contacts on inter

��dient and refuse to come out of its kennel, because of the variable current changes of the microphone mechanism, by which it was operated. The new means which Mr. Berger has invented to make the dog

obey every

���Ratctiet Magnet

Noise of hand- clap jars a small pendu- lum away from diaphragm and breaks the relay circuit

��Point of contact

��could light your way by the same means with- out hunting for the elec- t r i c light switches in the dark.

But what's the use of sup- posing? Mr. H. Christian Berger, a New York city in- ventor, has made all such things possible by inventing a new con- trivance which he calls a sound- operated circuit controller. Besides the utilitarian uses to -vVhich the device may be put, it may be employed for the opera- tion of mechanical toys of various sorts, including elec- tric railway trains, electric boats, hoisting derricks, or even the docile little wooden pup who jumps out of his kennel at your hand-clap com- mand — a toy first described in the November, 19H), issue of theP0PULARS<'i- ENCE Monthly.

While the mechanical pup, just mentioned, worked fairly well, on occa- ^,^^^^j^ ^^5,^^^^ ^^^ ^,^

Sions it would Introduction of a contrivance

become disobe- like this one adds novelty

��Sound -operated circuit.controller

���command without fail, is based on an entirely new principle and one wholly different from that of the microphone. While the lat- ter acts by varying the electric resist- ance and cur- rent in a cir- c u i t by changes of pressure and conductivity as a result of the action of sound waves — and does not break* the circuit — the sound-oper- ated circuit controller ac- tually does open the cir- cuit. These circuit breaks are made possible because two con- tacting members are used. . A diaphragm member con- tacting with a pendulum member un- der such

��The apparatus is small. It is but little larger than a lamp socket

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