The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 04, 1980
Filed:
Dec. 18, 1978
Daniel Lelaidier, Neuilly sur Marne, FR;
Pierre Godard, Tremblay les Gonesse, FR;
Saft-Societe des Accumulateurs Fixes et de Traction, Romainville, FR;
Abstract
The invention relates to electronic warning devices. The control system includes means for supplying an accurate clock signal and a divider (CD1, CD2) for dividing the clock signal to obtain an audio frequency, adjusting the mark/space ratio of the audio frequency for application to a power transistor (T6), said transistor driving a loudspeaker (HP), providing a cyclic modulation for modulating the clock frequency; and timing the duration of the sound emission of the loud speaker. The timing functions can all be provided without the use of electrolytic capacitors as would otherwise have been necessary, thereby avoiding problems due to the lack of precision and drift in the values of such capacitors.