Abstract: An apparatus and technique for providing a monitoring alarm telephone which not only automatically dials a predetermined alarm notification telephone number upon activation of a suitable alarm device (e.g., tripping of a motion detector), but which also provides audible monitoring of the secured premises using the automatically dialed telephone call. In one embodiment, an open channel is established between the monitoring alarm telephone and a called telephone allowing sounds from the secured premises to be passed on to the called party. A silent monitoring alarm is provided by muting the speaker of the monitoring alarm telephone upon activation of the alarm device. In another embodiment, a cordless telephone includes a motion detector and forms a monitoring alarm telephone. The microphone of either the remote handset or the base unit may be used to provide the monitored sounds to the automatically called party.

Abstract: An apparatus and technique for providing a monitoring alarm telephone which not only automatically dials a predetermined alarm notification telephone number upon activation of a suitable alarm device (e.g., tripping of a motion detector), but which also provides audible monitoring of the secured premises using the automatically dialed telephone call. In one embodiment, an open channel is established between the monitoring alarm telephone and a called telephone allowing sounds from the secured premises to be passed on to the called party. A silent monitoring alarm is provided by muting the speaker of the monitoring alarm telephone upon activation of the alarm device. In another embodiment, a cordless telephone includes a motion detector and forms a monitoring alarm telephone. The microphone of either the remote handset or the base unit may be used to provide the monitored sounds to the automatically called party.

Abstract: A battery charging circuit, a method of charging a battery and a battery-powered electronic device employing the circuit or the method. In one embodiment, the battery charging circuit includes a charging switch coupled between a base interface of the battery-powered electronic device and a battery thereof to be charged. When closed, the charging switch provides a conductive path for charge current from the base interface to the battery. The charge current is based on an input voltage of the battery charging circuit and a voltage of the battery. The battery charging circuit further includes a controller that modulates the charging switch at a duty cycle that at least in part determines a rate at which the charge current is delivered to the battery thereby to compensate at least in part for variations in the input voltage.

Abstract: Solid stage apparatus for the detection of synchronism between line and bus voltages in order to permit safer interconnection therebetween is disclosed. A first comparator circuit constantly monitors the magnitude of the vector difference between the line voltage and the bus voltage and generates a first enabling signal whenever the magnitude of the vector difference voltage is below a predetermined value. The first enabling signal will continue to be generated until the magnitude of the vector difference voltage rises above the predetermined value. A second comparator circuit monitors the relative magnitudes of the line and bus voltages and generates a second enabling signal whenever a high bus-dead line or a dead bus-high line circuit occurs. The second enabling signal will continue to be generated as long as one of these conditions exist. The enabling signals are applied to a time delay circuit.