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:
Feb. 23, 1988
Filed:
Feb. 24, 1987
Wilhelm Hegeler, Bad Salzdetfurth, DE;
Blaupunkt Werke GmbH, Hildesheim, DE;
Abstract
Pulses of constant pulse frequency but varying duty cycle are generated in a pulse generator which provides pulse trains or pulse sequences, as controlled by a pulse train or pulse length or sequence control unit coupled to the pulse generator and controlling the pulse generator to emit a train or sequence of pulses of similar pulse lengths, and further including a pulse length modulation control unit (12) coupled to the pulse generator and to the pulse train or sequence control unit, to control the length of the pulses of the individual pulse trains, the pulse lengths increasing in sequential pulse trains to provide an output signal of increasing intensity. The output from the pulse generator is filtered with respect to the base frequency, for example 800 Hz, and generated square wave pulses are converted into sawtooth wave pulses by a RC circuit to increase the dynamic range of output obtainable. The pulse generator (10), the pulse train length control unit (11) and the pulse length modulation control unit (12) can all form part of a digital microprocessor, generating the pulses, with intervening intervals to provide for a warning tone rhythm, the intervening intervals permitting the microprocessor to carry out calculating functions other than pulse generation for the warning tone.