Receiver control system

May 17, 1938.

2,117,638

J. C. WALTER

RECEIVER CONTROL SYSTEM

Filed Oct. 3, 1936

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INVENTOR.

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Patented May 17, 1938

2,117,638

UNITED STATES PATENT OFFICE

2,117,638

RECEIVER CONTROL SYSTEM

John C. Walter, Collingswood, N. J., assignor to Wired Radio, Inc., New York, N. Y., a corporation of Delaware

Application October 3, 1936, Serial No. 103,923

Claims. (Cl. 250—20)

My invention pertains in general to signalling systems and specifically relates to an arrangement for rendering signal receiving circuits effective under control of signals transmitted from a program source at a remote point.

The principal object of my invention consists in providing a system of program reception having a stand-by control circuit effective for initiating the operation of the system of program reception upon reception of signalling energy.

A further object comprises providing a signal receiver with a controlling switch which, when moved to a position for rendering the receiver inoperative, automatically initiates the operation of a stand-by control circuit for rendering the receiver operative upon receipt of signals intended for the receiver.

A still further object comprises providing a wired radio program system for automatically rendering receivers operative for reception of programs.

These and other objects will be apparent from the following, reference being had to the accompanying drawing which diagrammatically illustrates a preferred form of the receiver control system of the invention.

Referring to the drawing in detail, power lines I represent a wired radio distribution system including a commercial alternating current network upon which program modulated carrier frequencies are impressed in accordance with wired radio practice. A selective program filter 2 is capacitively coupled with the lines i for receiving therefrom various and selected carrier frequency bands for delivering program signalling energy to a wired radio receiver 3.

The receiver 3 comprises electrical circuits and electron tubes for receiving and reproducing a desired program. The electron tubes of the receiver 3 are energized by a circuit 4 which is connected to the lines f through a switch terminal 5, adapted to be engaged by a movable switch element 6. The switching element 6 is adapted to be manually controlled by the wired radio subscriber to energize the set 3 when it is desired to receive programs. When the subscriber “shuts down” receiver 3, he moves the switch element '6 out of engagement with the terminal 5, whereupon the switch element 6 engages with a terminal 7 connected through a transformer primary winding 8 to complete a circuit with the power lines I.

A secondary winding 9 supplies a low voltage operating current to an electron tube 10, biased to cut-off. The control element of the electron tube 10 is included in a resonant input circuit having an inductance (I and capacitor 12 connected therein. This input circuit for the tube 10 is capacitively coupled across power lines I. The resonance of this input circuit may be adjusted in several ways. In one instance, it may 5 be sensitive to carrier frequencies in a very broad band which embraces all of the frequency bands to which the program filter 2 may be sensitive in its selection operations. In another instance, the resonance of the input circuit for the tube 10 may 10 be adjusted so that it is responsive only to frequencies within a selected program passed by the filter 2, and, in another instance, the resonance of this input circuit to tube 10 may be adjusted to a special “monitoring” frequency entirely outside 15 of the frequencies normally passed by the filter 2.

The anode or output circuit of tube 10 includes connections 13 which provide an available supply of anode current for the tube 10. This output circuit also includes a milliammeter 14 for 20 closing a switch 15 having upper and lower contacts the upper contact being movable by and falling with the armature, the operation of which closes an energizing circuit from the power lines I to a solenoid 16 adapted to move the switch ele- 25 ment 6 from a position in engagement with contact 7 to a position in engagement with contact terminal 5.

When the receiver 3 is “shut down” the tube 10 is automatically energized for stand-by operation, 30 drawing a minimum amount of heating current and substantially no anode current. Upon reception of carrier frequency energy within the frequency range to which the input circuit of tube 10 is responsive, the control electrode of 35 tube 10 causes a flow of anode current which operates milliammeter 14 to close switch 15. Upon closure of switch (5 the solenoid IS is energized, whereupon the switch element 6 is actuated to engage terminal 5, thereby completing circuit 4 40 and initiating and maintaining the operation of receiver 3 until manually shut down. When the switch element 6 is thus moved, the energizing circuit for the tube 10 is interrupted so that the tube 10 does not become energized until the switch ⁴⁵element 6 is again manually moved and the receiver 3 is deenergized.

Although a preferred form of control system has been disclosed, it will be understood that vari- ₅₀ous changes and modifications can be made without departing from the intended scope of the invention. Therefore, no limitation is intended other than imposed by the appended claims.