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. 06, 1984
Filed:
Oct. 21, 1982
Uwe Matzold, Salzgitter, DE;
Dieter Heiss, Hildesheim, DE;
Robert Bosch GmbH, Stuttgart, DE;
Abstract
To decode control signals from a mixture of signals including audio signals, such as music, voice or speech, in which the control signals are within the audio range, for example 2,350 Hz, on which a low-frequency signal, for example in the 100-200 Hz range is modulated, the control signal in the form of a control tone is filtered and demodulated by band pass filters (1,3), demodulators and rectifiers (2,4), and then applied to a timing circuit (5) which provides an output signal if and only if the demodulated control tone is continuously applied during the timing interval thereof. Suitable timing intervals are about 1 second, to provide an output signal which can switch a flipflop (7) on, for example to command radiation of a particular type of recognition signal by the transmitter (13), the setting of the flipflop (FF) (7) being fed back to the timing circuit to change the timing interval thereof to a lesser amount, for example 1/2 seconds, to provide for a shorter signal to cause resetting of the FF (7). A second timing circuit (9) is provided to turn OFF the FF (7) in case it is overlooked to generate a 0.5 turn OFF signal and apply it to the first timing circuit (5).