DE601454C - Loudspeaker and amplifier arrangement - Google Patents

Description

GERMAN EMPIRE

ISSUED ON
AUGUST 16, 1934

REICH PATENT OFFICE

PATENT LETTERING

JVr 601454 CLASS 21a ² GROUP 16 oi

Patented in the German Empire on November 29, 1930

The invention relates to a loudspeaker and amplifier arrangement for use in devices for the electrical reproduction of sound vibrations.

Such arrangements are already known in which at least two on the input side amplifiers working in parallel feed the sound reproduction devices distributed in the room and arranged in groups.

The invention relates in particular to an arrangement of the type specified, which is used in the Playback of sound films or when broadcasting a speech ο. Like. To a large crowd by means of several loudspeakers arranged outdoors or in a large room from a central point or used for similar purposes.

In the systems for sound film purposes are preferably to achieve an acoustic Spatial effect in the projection screen several in relation to their effect on each other the same loudspeaker groups are arranged, each of which is connected to an associated amplifier is. These different amplifiers are mostly the electrical ones at the same time Vibrations supplied, the z. B. from a photocell, an electrical sound box, a Microphone, a radio receiver or the like.

originate. Such an arrangement has the disadvantage that if, for. B. in the use of two amplifiers with two associated loudspeaker groups, one of the amplifiers fails, a whole loudspeaker group is taken out of service. In particular in the case of devices for the reproduction of sound films this constitutes a major disadvantage, since the remaining sound is then produced solely by of the undisturbed speaker group is reproduced only from one side of the projection screen comes from, so that the acoustic spatial effect, as it exists with sound reproduction from both sides of the screen, is completely lost.

This difficulty is eliminated according to the invention in that the loudspeakers in groups electrically connected in parallel are divided, each of which has one or more Loudspeaker of each spatial group includes, and that each group of the electrical A switch of a known type is assigned to loudspeakers connected in parallel, with which they can be connected to any of the amplifiers. This ensures that in the event of failure an amplifier within "the groups only a part of the sound reproduction devices except Operation is set so that ζ. B. at the re-

*,) The patent seeker indicated the following as the inventors:

Albert von Sluiters, Willem Six and Anton Leendert Timmer in Eindhoven.

Claims (1)

would give the acoustic spatial effect of sound films, even if somewhat weakened, nevertheless is maintained. It is known per se for telephone and signal systems when an amplifier fails to have this replaced automatically by a reserve provided for this purpose. In the However, the device according to the invention does not have a reserve, but takes it over ίο after switching the intact amplifier the supply of the to the defective one Amplifiers belong to a group of sound reproduction devices. Of course there will be such a switch initially lead to the amplifier to which the additional load is switched will be influenced. By correctly dimensioning the amplifiers, however, the sound reproduction can be readjusted in such a way that that almost the same effect as before is achieved without any significant loss of time. The invention is explained in more detail with reference to the drawing, in. One embodiment is shown for example. In the amplifier arrangement shown schematically in the figure, the z. B. serves a to broadcast a speech 0 like that from a central point to a large crowd, are denoted by 19, 20 and 21 amplifiers, which simultaneously from a device such as z. B. a microphone or an electrical sound box, the electrical vibrations delivered are used by the groups of playback units, e.g. B. arranged at different points speakers in acoustic Vibrations are implemented. The amplifiers 19, 20 and 21 are via changeover switches 22, 23 and 24 connected to loudspeaker groups 25, 26 and 27. Each of these groups consists of six loudspeakers, which are connected in pairs. As can be seen from the figure, each group has each a set of two speakers connected to switches 22, 23 and 24. Each of the switch shown schematically has three contacts 19 ', 20' and 21 ' which lead to the amplifiers of the same name. The middle contact of each changeover switch causes the amplifiers to be connected to the associated ones during normal operation Loudspeaker groups. When one of the amplifiers, e.g. B. the amplifier 19, fails, so two loudspeakers from each loudspeaker group are thereby put out of operation; However the sound distribution remains almost the same, even if it is somewhat overall is weakened. You then have enough time to check which amplifier has failed. If this has been determined, in the present case the amplifier 19, then can the loudspeakers assigned to it by moving the switch 22 from the contact 19 ' can be switched to contact 20 'or 21' to one of the other amplifiers 20 or 21, whereupon this amplifier can be readjusted so that about the same sound effect as is achieved before. With the aid of the arrangement according to the invention it can thus be achieved that the disturbance is noticeable as little as possible. Patent application ·. Loudspeaker and amplifier arrangement, in particular for sound film systems, in which the Loudspeakers are arranged in groups in the room and distributed by at least two amplifiers operating in parallel on the input side are fed, characterized in that that the loudspeakers are divided into groups connected electrically in parallel, each of which comprises one or more loudspeakers from each spatial group, and that each group of loudspeakers connected electrically in parallel has a switch known type with which they are connected to each of the amplifiers can. 1 sheet of drawings