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Machine translation
1. (WO1980002477) PROTECTION DEVICE OR CIRCUIT FOR LOUDSPEAKERS
Latest bibliographic data on file with the International Bureau   

Pub. No.:    WO/1980/002477    International Application No.:    PCT/AU1980/000010
Publication Date: 13.11.1980 International Filing Date: 08.05.1980
IPC:
H02H 3/093 (2006.01), H02H 3/50 (2006.01), H04R 3/00 (2006.01)
Applicants:
Inventors:
Priority Data:
8700/79 08.05.1979 AU
Title (EN) PROTECTION DEVICE OR CIRCUIT FOR LOUDSPEAKERS
(FR) DISPOSITIF OU CIRCUIT DE PROTECTION POUR HAUT-PARLEURS
Abstract: front page image
(EN)A protection device for loudspeakers includes circuitry (16) for continuously measuring the average power of an audio signal delivered to a loudspeaker driver and detecting peak levels of said signal in both positive and negative directions. The circuitry (16) is adapted to provide a particular output to switching circuitry (T1) to activate a relay (13) when the average power exceeds a predetermined maximum for a predetermined time which would cause excessive heating in said driver or when said peak levels in either direction exceed predetermined limits set to correspond to the maximum positive or negative excursion limits of said driver. Activation of the relay causes switching of the audio signal path to the driver into an open circuit condition or switches a resistive load into the path to substantially reduce the power to the driver until overload ceases. Separate said circuitry is provided for each driver in a multi-driver speaker arrangement thus providing protection against distortion components in said audio signal caused by clipping. Optional circuitry (B4, R2, C2, 28, T2) for DC protection is also described as is an arrangement wherein the predetermined levels are user adjustable for incorporation into an audio amplifier.
(FR)Un dispositif de protection pour haut-parleurs comprend un circuit (16) de mesure continue de la puissance moyenne d"un audio-signal fournie a la commande d"un haut-parleur et de detection des niveaux de crete dudit signal dans les sens positif et negatif. Le circuit (16) est adapte pour fournir une sortie particuliere a un circuit de commutation (T1) pour actionner un relais (13) lorsque la puissance moyenne excede un maximum predetermine, afin d"eviter un echauffement excessif de ladite commande ou lorsque lesdits niveaux de crete excedent, dans l"un ou l"autre sens, des limites predeterminees etablies pour correspondre aux limites d"excursion positives ou negatives maximum de ladite commande. L"activation du relais entraine la commutation du cheminement de l"audio-signal vers la commande dans une condition de circuit ouvert ou commute une charge de resistance dans ce cheminement afin de reduire sensiblement la puissance fournie a la commande jusqu"a ce que la surcharge cesse. Un tel circuit separe est prevu pour chaque commande dans un dispositif haut-parleur a commandes multiples assurant ainsi une protection contre des composantes de distorsion dudit audio-signal dues aux coupures. Un circuit facultatif (B4, R2, C2, 28, T2) pour une protection a courant continu (DC) est aussi decrit ainsi qu"un dispositif dans lequel les niveaux predetermines sont reglables par l"usager, pour son incorporation dans un audio-amplificateur.
Designated States:
Publication Language: English (EN)
Filing Language: English (EN)