US2263298A - Signal receiver for remote control apparatus - Google Patents

Description

NOV. 18, 1941. Q HAIMBAUGH 2,263,298

SIGNAL RECEIVER FOR REMOTE CONTROL APPARATUS Filed July 18, 1940 2 Sheets-Sheet 2 I 20/ Z04 /6Z Ham/war! INVENTOR. fflgwo/va 6. Hal/1061107.

Patented Nov. 18, 1941 2,263,298 SIGNAL RECEIVER FOR REMOTE CONTROL APPARATUS Raymond C. Haimbaugh, North N. Y., assignor to The Rudolph pany, Cincinnati,

Tonawanda, Wurlitzer Com- Ohlo, a corporation Application July 18, 1940, Serial No. 346,130

2 Claims.

This invention relates, to a signal receiver for remote control apparatus which is particularly adapted to the selective control of automatic record changing phonographs. 1

One object of the invention is to provide a remote control in which selective operation may be accomplished by means of electrical signals transmitted over power lines supplying the operatingpower for the phonograph and for a remotely positioned transmission apparatus.

Another object of the invention is to provide improved apparatus for receiving such signals and for operating a phonograph in response to said signals.

The invention in its preferred form may be used with a transmitter unit oi' the type 'disclosed in co-pending application of Osborne and Wright, Serial No. 305,920, filed November 24, 1939, although other forms of transmitters operating upon the same general principle may be used. The transmitter is combined with a signal generating unit adapted to generate electrical signalsof frequencies above the audible range and to apply such signals to the power mains supplying the generating unit and the phonograph in the form of high frequency modulation of the normal alternating current voltages carried by said power mains.

" hold wiring. The

At the phonograph there is employed a novel form of receiving unit operating in response to the high frequency signals carried by the power mains and adapted to control the operation of the phonograph in accordance with such signals.

In the present application the invention has been shown in a form best adapted to control an automatic record-changing phonograph of the type disclosed in Wilcox Patent No. 2,002,236, issued May 21, 1935. However, adaptations to the control of other types of apparatus will be apparent.

Other objects and features of the invention will be understood from the accompanying drawings and the following specification and claims:

Fig. 1 is an elevational view with parts shown in section of mechanical portions ofva receiver constructed in accordance with a preferred form of the invention. Fig. 2 is a sectional view taken on the line 2-2 of Fig. 1. Fig. 3 is a diagram of electrical connections illustrating electrical elements used with the apparatus of Figs. 1 and 2, certain parts of said apparatus being-shown diagrammatically therein. Fig; 4 is a diagrammatical drawing illustrating the connection of the transmitter and a phonograph to the power line.

Referring first to Fig. 4, there is shown therein I54 and is normally urged in a pair of power mains 20 supplying power 22. The mains 20 may be taken to represent the usual distributory lines from the sub-station of the public utility, carrying alternating current voltages greaterthan that allowable for housepower lines 22 are the usual conductors supplying current for operation of lights and other appliances in the building in which the phonograph is to be used and preferably carry alternating current of 110 volts. cycles. A number of outlet sockets 23 are supplied from the power lines 22 and may be used for lighting fixtures 24 or other electrical appliances. In any one of said sockets there may be inserted a Dlug25 connected by a cable 25 to a transmitter unit 21. In another of said sockets may be inserted a plug 28 connected to a phonograph cabinet 29 and supp y ng current for operation of said phonograph and for operation of the signal receiving mechanism which may be housed in the cabinet of'said phonograph.

The transmitter 21 forms no part of the present invention and'need not be described in detail. It issuiflcient to say that it is adapted to modulate the normal voltage of the power lines Any suitable apparatus for generating such signals and impressing the same on the may be employed for the purpose.

The mechanical parts of the receiving apparatus are shown particularly in Figs. 1 and 2. The frame of the receiver consists of a pair of plates I53 and I54 secured together by spacer bolts I 55 and mounted in any convenient position adjacent the phonograph preferably within the cabinet of the phonograph itself. A shaft I55 is journaled in the plates I53 and the clockwise direction (Fig.2) by a torsion spring I51. Said shaft carries a ratchet I58 and a scanning finger I59. The tip of said scanning finger is adapted to engage electrical contact buttons I60 mounted on a dial I6! formed of insulating material and supported in any suitable manner on the plate I53. An electromagnet I62 is mounted on a bracket I63 secured to the plate I54 and when energized serves to lift an armature I54 pivotally mounted at I65. Said armature has secured thereto by means of a vertical pivot pin I56 an Dower lines arm I61. The resulting stricted upward movement released from the arm I61 projecting forwardly'through a suitable opening in the plate the lower corner of-said opening. Each actuation of the magnet I62 lifts the armature I64 and I engagement of said arm with the /teeth of the ratchet wheel I58 moves said wheel in the counterclockwise direction of Fig, 2 a distance corresponding to one tooth.

A pawl- I69 pivotally mounted on the plate I53 at I18 is urged by a tension spring I1I'toward engagement with the teeth of the ratchet wheel I58. 'An arm I12 pivotally mounted at I13.

extends, through a suitable opening in plate I53 to engage the tailof the pawl I69. Said arm is urged downwardly by a tension spring I14. A rod I15 ispivotally connected at its upper end to the arm I6I and rests at its lower end on the armature I64. Areduced extension I16 of said mally rests on the pawl 'I69andis held in that position bythe spring I14. vSaid pawl is thus and the spring I51 holds said ratchet wheel in an idle position in which a stop pin I19 carried by said wheel engages a stop member I88 carried by the plate I53. The electromagnet I62 is operated in. response the remote stations as will be described hereinafter. The first of a series of such signals causes 1 said magnet to move the ratchet wheel one space been found satisfactory for teeth of the ratchet wheel I58 to indexing signals from I53 and-normally retained .by a diagonally arranged tension spring I68 in I the same in proper relation thereto. A dashpot I11 in the counterclockwise direction. At the same time the rod I15 lifts the arm I12 from the tail of' the pawl I69 and permits the pawl to engage the teeth of the ratchet to retain the same in its new'position. Succeeding-indexing signals arrive at predetermined time intervals. The action of the dashpot I11 is so timed with relation to the timing of the signals that the arm I12 cannot reengage the pawl I69 in the interval between two successive signals. As long as a series of indexing signals continues, the ratchet I58 is moved one 'step by each signal and the pawl I69 prevents return movement. At the conclusion of a series, the spring I14 returns the arm I12 slowly to its original position, releases the pawl I69 and permits the ratchet wheel I58 to return to its original position under the influence of spring I51. During the movement of the ratchet wheel I58 the scanning member I59 restson a different one of the contact buttons I68 at each position. Thus the scanning member I59 is moved in synchronism with the signals .in the indexing series and engages a particular contact button during and immediately after each indexing signal of the series. I

Electrical circuitsassociated with the receiver just described are shownin Fig. 3. The plug 28 shown in said figure and in Fig. 4, when inserted in one of the sockets 23, provides a direct connection between the power lines 22 of Fig. 4 and a pair of power lines I98 and I9I of Fig. 4. The last mentioned power lines therefore receive the usual commercial alternating current modulated by the high frequency signals generated at the transmitter. Power for operating'the controlled machine may be taken from the power lines I98 and I9I as shown in the drawings by connection of these lines to the rectangle marked "Phonograph mechanism.

A pair of input transformers I92 and I99 have their primary windings connected across the power lines I98 and I9I through condensers I94 and I95 respectively. The secondary windings of the transformers I92 and I93 are connected in the grid circuit of an amplifier tube I98 which may be the usualmentode tube connected in the conventional manner shown in the drawings. The circuits of the transformers I92 and I93 are tuned to transmit to the amplifier tube only high frequency energy having the frequencies of the indexing and selection signals respectively. Direct current for operationof the amplifier tube I96 is supplied by a rectifier I91 which establishes the necessary direct current potential between a conductor I98 and the power line I98 which serves as the high voltage direct current distributory as well as an alternating current power line.

The output circuit of the tube I96 is connected to the primary windings of a pair of transformers I99 and 288. The secondary windings of I said transformers are provided with bridging condensers 28I and 282 properly chosen to provide tuned circuits sensitive respectively to \the frequencies of the indexing and selection .signals. One terminal of eachof said secondary windings is connected to the low voltage direct current conductor I98 through a resistance 283. The opposite terminal of the secondary winding of transformer I99. is connected to the control grid of a gas filled triode discharge tube 284 and the'secondary winding of transformer 288 is similarly connected to a similar tube 285. The anode of the tube 284is connected through a relay coil 286, anorm'ally open switch 281 and a radio fre quency choke coil 288 to the power line I9I. The anode of the tube 285 is similarly connected through a relay coil 289. The cathodes of the tubes 284 and 285 are connected to the power line I98. Thus when the switch 281 is closed, alternating voltage is established between the anodes and cathodes of said tubes. In the idle condition of the apparatus, however, the control grids of said tubes are biased to cut off by their connection through the secondary windings of the transformers I99 and 288 to the low voltage direct current line I98. Thus, inthe absence of a high frequency signal, no current flows through the tubes 284 and 285. The presence of a signal voltage of the predetermined high frequency in the transformers I99 and 288 causes the potential of the control grids of said tubes to be raised suiiiciently on alternate half cycles to pass current through said tubes to operate the relay coils 286 and 289. a

To prevent establishing the alternating voltage across the elements ofsaid tubes before the control grids can be biased to cutoff; a direct current v relay coil 2 I8 is connected between the power line I98 and the lowvoltage direct current line I98 and serves when energized to close the switch 281. Thus, when current is first established, the

direct current voltage must be built up sufliciently to operate the relay coil 2" and to biasthe grids of tubes 284 and 285 before switch 281 may be closed to establish the alternating potential across said tubes. Ame use of the relay 2I8 .tubes by pulling and frequency of the selection of the scanning arm thus prevents unauthorized operation of said replacing the plug 28.

By means of the wiring just described, the high frequency modulations received on the power lines I90 and I 9| are amplified by the tube I96 and are caused to operate the discharge tubes 204 and 205.. The characteristics of the circuit associated with tube 204 are such that it re-, sponds only to the frequency of the indexing signal: Similarly the characteristics of the circuits associated with the tube 205 respond only to the signal. Thus the relay 206 is actuated in response to each indexing signal and the relay 209 is actuated in response to each selection signal.

The relay 206 when actuated closes a switch 2 which connects the electromagnet I62 of the receiver directly across the power lines I90 and I9I and thus actuates said magnet to move the scanning member I59. The relay 209 when actuated in response to each selection signal closes a switch 2I2 which-connects the scanning arm I59 to the power line I90. Each of the contact buttons I60 is connected to one of a series of electromagnets 2I3, each of which is adapted to control an operation of the machine. When op-- crating a phonograph of the type shown in Wilcox Patent No, 2,002,236; the magnets 2I3 correspond to the magnets I15 of the Wilcox machine, each of which is adapted to control the selection of a predetermined record for playing..

Each of said magnets has its opposite terminal connected to the power line I 9| and thus the closure of switch 2I2 causes the actuation of one of. said magnets depending upon the position I59. A magnet coil 2 is connected directly between the switch 2I2 and the power line I9I and is thus actuated each time that one of the magnets 2I3 is actuated. This magnet corresponds to magnet I50 in the Wilcox patent and serves to start the operation of the machine when the first selection signal is received and to continue such operation toplay as many records as have been selected. While the magnets 2I3 and 2 have been shown separated from the phonograph mechanism in the drawings for sake of convenience, it is to be understood that they form a part thereof.

The invention has been described in one of its preferred forms, the details of which may be varied -by those skilled in the art without departing' from the scope thereof as defined by the'appended claims.

The invention claimed is:

1. In a receiver for a remote control system operated by modulated carrier signals received between said rectifier, said cathode, and said conelectrodes,

trol electrode normally applying a biasing voltage to said control electrode to prevent current flow in said anode-cathode circuit, apparatus responsive to said carrier signals and associated with electrode to change the potential thereof suiiiciently to permit current flow in said anode-cathode circuit when a modulated signal is received, a relay connected to receive at least a part of the biasing voltage of said control electrode and adapted to be actuated only when said biasing voltage has been established at a predetermined amount, and a switch in said anodecathodecircuit operated by actuation of said relay, said switch being open to prevent operation of said circuit when said relay is deenergized.

2. Ina receiver for a remote control system operated by modulated carrier signals received I on an alternating current power line, the subcombination including a pair of electron valves each having a cathode, an anode, a control electrode, and an anode-cathode circuit, a rectifier receiving energy from said power line, and supplying direct current energy to both of said anode-cathode circuits, an electrical device to 'be controlled included in each of said circuits, a

grid biasing connection for each of said control connected to said rectifier and normally applying a biasing voltage to said control electrodes to prevent current flow in said anodecathode circuits, a pair of tuned receiving circuits'each responsive to signals of a different predetermined carrier frequency and each associated with one of said control electrodes and adapted to change the potential thereof sufliciently to permit current flow in the corresponding anode-cathode circuit when a signal of the predetermined carrier frequency is received, a relay associated with said grid biasing connections and receiving at least a part of the biasing voltage and adapted to be actuated only when said biasing voltage has been established in a. predetermined amount, and

switching meanscontrolling both of said anode-cathode circuits operated by said relay to prevent current

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