Communications: electrical – Audible indication
Patent
1994-07-29
1997-03-18
Hofsass, Jeffery
Communications: electrical
Audible indication
340539, 34082569, 34082572, 3403847, 341176, 455336, 455339, G08B 300
Patent
active
056126662
ABSTRACT:
A wireless audible indication system comprising a transmitter and a receiver. An embodiment of the transmitter includes a crystal oscillator which produces a signal having a predetermined audio frequency. A duty cycle limiting circuit limits the duty cycle of the oscillator signal to be less than 25%. The limited duty cycle signal is applied to a radio frequency oscillator to produce an amplitude modulated radio frequency signal. An embodiment of the receiver includes a superregenerative detector which provides wide band detection of transmissions about a carrier frequency. A signal processing circuit formed by a cascade of a crystal filter stage, an amplifier/comparator stage, and a detector stage, processes the signal from the superregenerative detector. A sound generator integrated circuit, which generates an audible signal indicative of reception of a transmitted signal, is coupled to the signal processing circuit. Another embodiment of the receiver includes two parallel signal processing paths having different crystal filter stages, which allows use with two different transmitters.
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Fasco Industries Wireless Chime Program, Mar. 15, 1993.
Phamphlet by Dimango Products--Dimango's 1993 Wireless Chime Program.
Dimango Products Inc.
Hofsass Jeffery
Pope Daryl
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