Abstract: A telephone ring detector detects a ring signal voltage from a diverse set of signals transmitted on a telephone line before a complete alternating current ring signal cycle is received. In an exemplary embodiment, the ring detector includes a voltage threshold setting device for establishing a voltage threshold and comparing the ring signal voltage to the voltage threshold to provide an output signal when the ring signal voltage is above the voltage threshold. A pair of zener diodes having a selected voltage value can provide the threshold setting and comparison functions. A microprocessor, including a timer for measuring a time duration of the output signal, outputs a ring detection signal when the time duration exceeds a predetermined time interval value, which is substantially less than a full ring cycle. A line switch responsive to the ring detector is provided to direct communication signals to a telecommunications device.

Abstract: A closed-loop system for monitoring the condition of a person in a residence. A digital dialer-transceiver at the residence is connected to a telephone line and may be triggered by an emergency button or the running out of a timer. It transmits identification and alarm codes to a compatible digital transceiver at a central station and at the same time emits an alarm signal at the residence. The central station digital receiving unit acknowledges the communication, means being provided in response to this acknowledgement for changing the "alarm" signal at the residence to a "call received" signal. The central station operator calls emergency responders previously recruited for that residence. The responder arriving at the residence presses a reset button on the unit which transmits an "all clear" signal to the central station and changes the "call receive" mode of the residence signal to an "all clear" mode.

Abstract: An alarm system for automatically sending a telephone message or other remote signal in case help is needed for a person residing alone. In one version, a timer cyclically activates a magnetic tape player which begins slowly to dial the number of the station at which help is available, and then transmit a prerecorded message. The timer simultaneously activates an audible warning signal so that the resident can abort sending of the message if no help is needed. The timer is automatically reset each time the resident lifts the handset in normal telephone usage so that it is unnecessary under ordinary circumstances for him to worry about resetting the timer each day. Should the audible signal be activated but there is no need for help, the signal may be shut off, the message sending aborted and the timer reset merely by lifting the handset. A manual emergency bypass switch is provided.