Description of the Invention
The present invention relates to a speaker switching device. More particularly, the invention relates to a speaker switching device for a radio having a radio power supply and producing a radio speaker output and a tape deck having a tape deck power supply and producing a tape deck speaker output when a tape cartridge is inserted therein.
Objects of the invention are to provide a speaker switching device of simple structure, which is inexpensive in manufacture, eliminates any duplication of speakers by permitting a single set of speakers to be used selectively for a radio and a tape deck, and functions efficiently, effectively and reliably to produce sound provided by a radio and a tape deck, selectively, with fidelity.
In order that the invention may be readily carried into effect, it will now be described with reference to the accompanying drawing, wherein:
FIG. 1 is a block diagram of an embodiment of the speaker switching device of the invention; and
FIG. 2 is a circuit diagram of the embodiment of FIG. 1.
In the FIGS., the same components are identified by the same reference numerals.
The speaker switching device of the invention is for a radio 1 having a radio power supply 2 and producing a radio speaker output 3, and a tape deck 4 having a tape deck power supply 5 and producing a tape deck speaker output 6 when a tape cartridge (not shown in the FIGS.) is inserted therein.
The speaker switching device of the invention comprises a single pair of speakers 7 and 8. Relay contacts including fixed contacts 9a, 9b, 9c, 9d and 9e and movable relay armatures 9f, 9g and 9h are provided. A relay energizing winding 9 controls the positioning of the movable relay armatures 9f, 9g and 9h relative to the fixed relay contacts 9a, 9b, 9c, 9d and 9e.
Circuit conductors 10, 11, 12, 13, 14 and 15 electrically connect the speakers 7 and 8 to the radio speaker output 3 and to the tape deck speaker output 6 via the relay contacts 9b, 9c, 9d, 9e, 9f and 9g. Thus, as shown in FIG. 2, in a first position of the relay armatures 9f and 9g, as shown in FIG. 2, the radio speaker output 3 is electrically connected to the speakers 7 and 8 via the electrical conductors 13 and 10 and 12 and 11, and the tape deck speaker output 6 is disconnected from said speakers.
In a second position of the relay contacts 9f and 9g, not shown in FIG. 2, the tape deck speaker output 6 is electrically connected to the speakers 7 and 8 via the electrical conductors 14 and 10 and 15 and 11 and the radio speaker output 3 is disconnected from the speakers. This is accomplished by the movement of armatures 9f and 9g under the control of the relay energizing winding 9.
In the first position of the relay contacts, the relay armatures 9f and 9g are in their positions shown in FIG. 2 in contact with the relay contacts 9c and 9b, respectively. In the second position of the relay contacts, the relay armatures 9f and 9g are in electrical contact with the relay contacts 9e and 9d, respectively.
A current-sensitive switch or transistor 16 is electrically connected to the relay energizing winding 9 via an electrical conductor 17, and to the tape deck power supply 5 via an electrical conductor 18. The current-sensitive switch 16 is electrically connected to the radio power supply 2 via electrical conductors 19 and 20 when the relay armature 9h is in its first position, in electrical contact with the relay contact 9a, as shown in FIG. 2.
The current-sensitive switch 16 is disconnected from the radio power supply 2 and the relay energizing winding 9 is energized by the tape deck power supply 5 to move the relay armatures 9f, 9g and 9h to their second positions when a cartridge is inserted in the tape deck 4. This is due to the switch 16 changing its condition upon the increased current flow therethrough produced when a cartridge is inserted in the tape deck.
While the invention has been described by means of a specific example and in a specific embodiment, I do not wish to be limited thereto, for obvious modifications will occur to those skilled in the art without departing from the spirit and scope of the invention.