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Patent Agency Ranking
公开(公告)号：AU511332B2
公开(公告)日：1980-08-14
申请号：AU2786277
申请日：1977-08-12
Applicant: GEN SIGNAL CORP
Abstract: A dynamic loudspeaker is driven by chopped d.c. from the collector of a transistor. A free wheeling diode is connected in parallel with the speaker circuit to dissipate the inductive energy in the speaker voice coil when the transistor is turned off. The transistor is controlled by a voltage controlled oscillator which, under control of other elements, can be made to produce a wide variety of cyclically varying output signals for producing a wide range of sounds, tones and signals from the loudspeaker. This permits selection of a tone which differs sufficiently from the ambient noise to assure attracting attention. By the use of chopped d.c. to drive the speaker, the expense, weight and bulk of an impedance matching transformer is eliminated. A plurality of individually operable switches are provided for switching circuit elements in and out of circuit to modify wave shapes and alter sound output. Another group of individually operable switches mixes selected wave shapes to produce various compound waves and produce additional sound variations. One switch provides pitch control and another provides output volume control.
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公开(公告)号：ZA774837B
公开(公告)日：1978-06-28
申请号：ZA774837
申请日：1977-08-10
Applicant: GEN SIGNAL CORP
Abstract: A dynamic loudspeaker is driven by chopped d.c. from the collector of a transistor. A free wheeling diode is connected in parallel with the speaker circuit to dissipate the inductive energy in the speaker voice coil when the transistor is turned off. The transistor is controlled by a voltage controlled oscillator which, under control of other elements, can be made to produce a wide variety of cyclically varying output signals for producing a wide range of sounds, tones and signals from the loudspeaker. This permits selection of a tone which differs sufficiently from the ambient noise to assure attracting attention. By the use of chopped d.c. to drive the speaker, the expense, weight and bulk of an impedance matching transformer is eliminated. A plurality of individually operable switches are provided for switching circuit elements in and out of circuit to modify wave shapes and alter sound output. Another group of individually operable switches mixes selected wave shapes to produce various compound waves and produce additional sound variations. One switch provides pitch control and another provides output volume control.
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公开(公告)号：ZA7506551B
公开(公告)日：1976-09-29
申请号：ZA7506551
申请日：1975-10-16
Applicant: GEN SIGNAL CORP
CPC classification number: B06B1/0261 , B06B2201/53 , H03K17/64
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公开(公告)号：ZA756551B
公开(公告)日：1976-09-29
申请号：ZA756551
申请日：1975-10-16
Applicant: GEN SIGNAL CORP
Abstract: An electronic circuit including a transistor which is biased to conduction is provided to initiate actuation of an electromagnetic transducer. The transducer has first and second coils one of which actuates the sounder. A potential is induced in the other coil and this induced potential is used to cut off the transistor. The next cycle of operation is initiated when the induced potential falls below a predetermined value in response to the reduction of the magnetic flux which, in turn, was the result of the transistor having been cut off.
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