Abstract: According to the present invention, a relatively straightforward, cost-effective technique for eliminating and/or reducing inaccuracies, such as amplitude induced timing errors, is provided in a pulse detection system without reducing bandwidth or degrading the signal-to-noise ratio. Exemplary embodiments detect a change in polarity of slope in a pulse of received energy to provide accurate pulse detection in the presence of noise, without degrading signal-to-noise ratio. Exemplary embodiments can create a time-invariant pulse from a single received, amplitude variant pulse, wherein a rising edge of the detected pulse is coincident with a change in a polarity of slope of the received pulse. Thus, a repetitive pulse signal is not needed to provide accurate pulse detection. Further, exemplary embodiments eliminate any need for complex circuitry since, for example, they are based on using cost-effective differentiators and do not require a reset signal to be asserted between pulses.

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.

Abstract: A wireless audible indication system comprising a transmitter and a receiver. An embodiment of the transmitter includes a modulator formed by a microprocessor and a radio frequency oscillator. The modulation format employed is selectable by the user using severable jumper wires. A battery status circuit is included which verifies the status of a battery within the transmitter. The modulator transmits a low battery bit to the receiver in order to alert the user of a weak transmitter battery. An embodiment of the receiver includes a superregenerative detector which produces an intermediate signal upon receiving a radio frequency signal. A signal processing circuit, which includes an active peak detector stage and a discrete comparator stage, is used to process the intermediate signal. A microprocessor controls a sound generator circuit in response to the processed intermediate signal.

Abstract: The monitoring assembly (10) monitors the location of mobile objects (12), i.e., personnel, within a structure (18). The object (12) carries a transponder (14) which periodically transmits status signals and receives command signals. Transceivers (16) are fixed at locations about the structure (18) for receiving the status signal producing the location signals, and transmitting commands to the transponders. The transmissions and reception occur during prescribed time windows. A central controller (20) is connected to each transceiver (16) and monitors the location of transponders (14) and communication therethrough. The transponders (14) have audio capability of producing audio messages directly to the person thereof, especially during emergency conditions for assistance. The controller (20) transmits synchronizing signals to the transceivers (16), which in turn synchronize themselves and transmit the synchronizing signal to the transponders (14) for synchronizing.

Abstract: The musical wireless alerting system includes several detectors (12) which transmit rf signals to a common receiver (14). The detectors (12) include manual switches thereon to allow manual selection of a song or melody. The selection is coded in the form of an audio code which is transmitted to the receiver (14). The receiver (14) detects any rf transmissions and verifies that the received transmissions are identifiable with the receiver (14). Upon verification, the receiver reads the audio code and compares same to a plurality of stored songs or tones within memory for transmission to a speaker which plays the tone or song. Each of the detectors (14) may sense different predefined conditions and indicate different audible indications to be played. The detectors may sense conditions such as opening of the door or depression of a door bell.

Abstract: An illumination level control device (10) is disclosed which sequentially reduces the illumination level of a multi-bulb lamp (12). The illumination level control device (10) incorporates two D flip-flops (38,40) configured in a master-slave relationship wherein the two D flip-flops (38,40) change their respective states when the clock (60) sends a positive-edge of the clock signal thereto. A portion (58) of the device (10) sets the two D flip-flops (38,40) when the wall switch (22) is off for more than a predetermined time. In the case of a three bulb (14,16,18) lamp (12), a zero state preventor (56) prevents all of the bulbs (14,16,18) from being turned off when the wall switch (22) is in the ON position. The zero state preventor (56) effectively eliminates the state wherein the outputs of both of the two D flip-flops (38,40) are low.

Abstract: The monitoring assembly (10) monitors the location of mobile objects (12), i.e., personnel, within a structure (18). The object (12) carries a transponder (14) which periodically transmits status signals and receives command signals relating to audio control. Transceivers (16) are fixed at locations about the structure (18) for receiving the status signal producing the location signals, and transmitting commands to the transponders. The transmissions and reception occur during prescribed time windows. A controller (20) is connected to each transceiver (16) and monitors the location of transponders (14) and communication therethrough. The transponders (14) have audio capability of producing audio messages directly to the person thereof.