Abstract: A system generates an alarm at one unit of the system when a second unit of the system is more than a predetermined distance from the first unit. The system has a first transceiver unit with a first transmitter for transmitting a first reference signal having a phase with respect to a reference source, and a first receiver for detecting a second reference signal having a phase which bears a relationship to that of the first reference signal. There is a second, portable, transceiver unit with a second transmitter for transmitting the second reference signal after receipt of the first reference signal. The first transceiver unit includes a distance resolver for determining the distance between the two transceiver units from the phases of the first and second reference signals, and an alarm, responsive to the distance resolver, for generating an alarm signal if the distance between the two transceiver units is more than a predetermined amount.

Abstract: A switching control circuit for energizing a lamp in response to a decrease in ambient light below a predetermined level includes a photosensor and a timer circuit that responds to the photosensor indicating that the ambient light level is below a predetermined level by gating a solid state switching device into conductance to energize the lamp. The photosensor is powered by the signal that gates the switching device in a manner that renders the photosensor operative only when the lamp is not energized. Therefore, the lamp is energized upon the onset of dusk for a predetermined period of time during which the photosensor is disabled. After the period of time has expired, the lamp is deenergized and the photosensor is again enabled for a brief period of time to determine whether ambient light is still below the predetermined level. If it is, the light is again energized for another period of time. If not, the light remains deenergized.

Abstract: A flashing alarm device responsive to audible signals produced by a smoke detector when the smoke detector senses a smoke condition, the alarm device including a circuit with a microphone portion for responding to audible signals produced by the smoke detector and an amplifier circuit portion for amplifying signals produced by the microphone, a switch circuit portion having a control input connected to the output of the amplifier circuit portion, and another circuit portion including a battery, a timer circuit, and a light bulb, the battery having a connection to the amplifier circuit and to the timer circuit, the timer circuit and the light bulb being connected in series with the switch circuit portion for energizing and de-engergizing the light bulb whenever the switch circuit portion is in its conducting condition. The device may also include a housing for the components and the device may optionally be constructed to operate on transmitted and received radio frequency signals.

Abstract: Method of and apparatus for heating or cooking a food product packaged within a container by using heated air. The oven apparatus includes a substantially closed-loop heated air system that starts with a blower that blows air into a heating barrel where a heating element heats the air to a high temperature. The heated air exits the heating barrel, passes through an air flow channel in the oven's door, and enters the oven's heating chamber. The heated air passes through the container inside the heating chamber and heats the food product within the container. In a preferred embodiment of the invention, the heating chamber is rotated while the heated air passes through the container to tumble the food product and ensure even heating thereof. The air exiting from the food product container enters a recirculation chamber which directs the air back into the blower to repeat the cycle.

Abstract: A battery charger device and method including a charging circuit having a source of charging energy and connections for installing one or more batteries to be charged, the device having a controllable switch associated with each battery to be charged and a microprocessor for controlling the switches to establish a charging sequence of distinct repeated charging periods for each battery, a display device associated with each battery under control of a microprocessor for individually indicating the charging status of each battery, the microprocessor having inputs at which various parameters with respect to the batteries being charged are applied such as battery voltages, ambient temperatures and charging currents, the microprocessor being programmed to terminate a voltage charging operation with respect to any one or more of the batteries if the measured difference between the charging and non charging voltage of any one or more of the batteries during succeeding charging periods exceeds some predetermined valu