US2184565A

US2184565A - Sound picture apparatus

Info

Publication number: US2184565A
Application number: US203354A
Authority: US
Inventors: Joseph S Pesce
Original assignee: RCA Corp
Current assignee: RCA Corp
Priority date: 1938-04-21
Filing date: 1938-04-21
Publication date: 1939-12-26
Anticipated expiration: 1956-12-26

Description

Dec. 26, 1939. J. s. PESCE soUND PICTURE APPARATUS Filed April 2l, 1938 QMJIIIIIIIIII Snventor Tlllllll llllll |.I s Y www Hl Q Patented Dec. 26, 1939 UNITED STATES DBHVCH PATENT OFFICE SOUND PICTURE APPARATUS of Delaware Application April 21, 1938, Serial No. 203,354

6 Claims.

This invention relates to an improved sound picture apparatus, and more particularly to a change-over device for switching from one sound reproducer to another at the end of a reel of lm.

In such devices heretofore constructed, the volume control was usually located in the amplier, precluding a presetting of the volume control for the incoming machine, since the volume control had to be retained in circuit until the outgoing machine was disposed of. In other types of such apparatus, separate volume controls for the several machines were provided, which required volume control at low levels, thereby introducing noise, and which prevented a unied volume control permitting of remote control.

In my improved apparatus, I locate the volume controls between the voltage amplifier and the power amplifier, providing a separate volume control for each projector, and the volume control circuits are switched simultaneously with the projector, thereby permitting unitary control of the volume controls, presetting of the individual volume controls, and control of the volume during the projection of the picture from a remote point.

One object of my invention is to provide an improved change-over device.

Another object of my invention is to provide an improved switching arrangement.

Another object of my invention is to provide an improved type of volume control.

Another object of my invention is to provide an improved volume control which controls the Volume at high electrical levels.

Another object of my invention is to provide a volume control having a remote control and having projection room control for the individual machines.

Other objects of my invention will be apparent to those skilled in the art from a reading of the following specification and an inspection of the accompanying drawing, in which the single gure is a schematic diagram of the connections of my apparatus.

In the drawing, the input from the several soundheads is represented as being fed through the three transformers I0, II and I2, which are connected in series. The output from these transformers is fed to a rotary switch I3 which short-circuits the output from the two soundheads which are not in service. The output from the soundhead in service, which in the position of the switch illustrated, is that numbered II, is

fed to the voltage ampler I4. Output from the voltage amplier I4 is transmitted to a second rotary switch I5, and is selectively directed to the several attenuators I6, I1 or I8, as may be required. These attenuators are illustrated as a modified T-pad type of attenuator, but it will be apparent to those skilled in the art that H-pads or any other equivalent type of attenuator may be substituted therefor.

In the position of the switch I5 shown, which corresponds to the position of the switch I3, matching the soundhead II in the circuit, the output from the switch I5 passes to the attenuator I1. The output from this attenuator I1 passes through the leads I9 and 20 to a third rotary switch 2 I, which in turn connects, through the leads 22, to the link circuit 23. The output from the link circuit 23 passes in the usual manner, through the power amplifier 24, to the loudspeaker or loudspeakers 25.

The three controls of each of the T-pads indicated are interconnected, as indicated schematically in the drawing, so that the three resistors are changed in value simultaneously. Each of these attenuators I6, I1 and I8 is connected through an appropriate clutch 26, 21 and 28, to a centralized control unit 29, which may be a capacitor motor, Selsyn motor, or solenoid control device adapted to be controlled from some remote point, such as an auditorium. This connection between the several attenuators may likewise be provided in the projection room, or at some other convenient point, with common manual controls 3U.

The several attenuators I6, I1 and I 8 are provided with the usual indicia of their settings, so that they may be preset in accordance with the volume indications on each reel of film by releasing the corresponding clutch 26, 21 or 28, and adjusting the attenuator of the incoming machine to correspond with the aforesaid markings. Any control of the general level of reproduction is accomplished either by the manual controls 30 or the remote control 29, and controls all of the attenuators simultaneously, independently of the relative volume settings required by the several soundheads. In this Way, as the volume of sound reproduction required increases, due to an increased audience, the sound reproducer may be adjusted to suit the requirements, independently of the relative adjustment of the several reproducers required by the sound records being played therein or about to be played therein.

Having now described my invention, I claim:

l. Apparatus of the class described including a nUUll plurality of electrical sound reproducers, a. power amplifier, a voltage amplifier, a plurality of volume control devices corresponding in number with the sound reproducers and arranged to be connected between said voltage amplier and said power amplier, and means for simultaneously selecting one of said sound reproducers and the corresponding volume control device, said means including interconnected switches between said sound reproducers and said voltage amplifier, and betwen said voltage amplifier and said volume control devices.

2. Apparatus of the class described including a plurality of electrical sound reproducers, a power amplifier, a voltage amplifier, a plurality of volurne control devices corresponding in number with the sound reproducers and arranged to be connected between said voltage amplifier and said power amplier, and switch means for simultaneously selecting one of said sound reproducers and the corresponding volume control device, said switch means including interconnected switches between said sound reproducers and said voltage amplier, and between said voltage amplier and said volume control devices.

3. Apparatus of the class described including a plurality of electrical sound reproducers, an amplifier, a plurality of volume control devices corresponding in number with the sound reproducers and arranged to be connected to the output of said amplifier, and means for simultaneously selecting one of said sound reproducers and the corresponding volume control device, said means including interconnected switches between said sound reproducers and said ampller and between said amplier and said volume control devices.

4. Apparatus of the class described including a plurality of electrical sound reproducers, an amplier, a plurality of volume control devices corresponding in number with the sound reproducers and arranged to be connected to the output of said amplier, means for simultaneously selecting one of said sound reproducers, and the corresponding volume control device. said means including interconnected switches between said sound reproducers and said amplifier and between said amplifier and said volume control devices, and common control means for said devices.

5. Apparatus of the class described including a plurality of electrical sound reproducers, an amplier, a plurality of volume control devices corresponding in number with the sound reproducers and arranged to be connected to the output of said amplifier, means for simultaneously selecting one of said sound reproducers and the corresponding volume control device, and common remote control means for said volume control devices.

6. Apparatus of the class described including a plurality of electrical sound reproducers, an amplifier, a plurality of volume control devices corresponding in number with the sound reproducers and arranged to be connected to the output of said amplifier, means for simultaneously selecting one of said sound reproducers and the corresponding volume control device, said means including interconnected switches between said sound reproducers and said amplifier and between said amplifier and said volume control devices, and common remote control means for said devices.

JOSEPH S. PESCE.