Title: Muting circuit for a radio receiver

Abstract: A zero crossing detector and one shot circuit connected to receive audio frequency signals from a receiver and provide a pulse each time the signal crosses a reference level, first and second one shot timers connected to receive the pulses and provide pulses in response thereto which coincide with the zero crossing of a predetermined signal it is desired to mute, coincidence gates receiving the one shot pulses and the delayed pulses and cooperating with a missing pulse detector and a relay in the receiver to mute the receiver whenever the pulses from either of the one shot timers coincide with the pulses from the zero crossing detector, which coincidence indicates a signal of the frequency it is desired to mute.

Do you think this is a good invention? Vote now:

Votes so far: For:(0) Against:(0)
Other info:

Inventors: Cohlman, Donald C. (Rolling Meadows, IL, US)

Application Number: 526485
Filing Date: 1974-11-25
Publication_date: 1976-02-17
Assignee: Motorola, Inc. (Chicago, IL)
Primary Class(es): 375/217 375/351, 455/221
Other Classes:
US Patent Ref:

3437937	Apr, 1969	Warfield	325/478.
3564419	Feb, 1971	Yackish	325/478.
3603884	Sep, 1971	Zaur, Jr.	325/478.
3633112	Jan, 1972	Anderson	325/478.
3758856	Sep, 1973	Fromm	328/110.
3843928	Oct, 1974	Nishimura et al.	325/478.

Other Refs:
Primary Examiner: Griffin, Robert L.
Assistant Examiner: Ng, Jin F.
Attorney: Gillman; James W., Parsons; Eugene A.