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:
Sep. 07, 1976
Filed:
Sep. 16, 1974
David M Motley, Santa Ana, CA (US);
King Y Cheng, Tustin, CA (US);
Richard W Middlestead, El Toro, CA (US);
Hycom Incorporated, Irvine, CA (US);
Abstract
A demodulator for detecting first and second frequencies in an analog input signal includes a limiter providing first pulses having a short duration in response to the first frequency and having a long duration in response to the second frequency. A first counter provides a first reference signal including second pulses, and a second counter provides a second reference signal including third pulses. Logic means responsive to the second and third pulses provide a signal including fourth pulses during periods corresponding to the first frequency and a signal including fifth pulses during periods corresponding to the second frequency. An up-down counter is responsive to the fourth pulses to provide a first output signal and responsive to the fifth pulses to provide a second output signal. The fourth and fifth pulses have frequencies and durations providing the counter with substantially equal counting rates during the periods corresponding to the first and second frequencies of the analog signal.