Abstract: A system for selectively providing power from a power source to a load to operate in an area for at least one occupant comprising a processing device for controlling the opening and closing of a relay connected between the load and the power source for energizing the load, and a sensor for detecting the presence of an occupant in the area. The processing device is programmable to close the relay in response to an output signal from the sensor for a period of time that can be of fixed duration, or a duration that is dynamically and automatically determined using sensor data relating to measure time between successive, detected occupant movements. In addition to a daylight inhibit function, the system is provided with color indicators and a tone generator to indicate various operating conditions and to guide a user entering selected system parameters, among other features.

Abstract: A power supply circuit is provided for use in combination with a load and an alternating current (AC) power source for selectively connecting and disconnecting the load and the AC power source. The load is connected between a neutral conductor of the AC power source and the power supply circuit. The power supply circuit is connected to a power or hot line conductor and a ground conductor of the AC power source. The power supply circuit comprises relay connected in series between the load and the line conductor; a control circuit for selectively operating the relay; and a transformer. The primary winding of the transformer is connected in series with the line conductor and the ground conductor for supplying power to the control circuit even when the load is disconnected from the AC power source. The power supply circuit comprises a switch in series with the primary winding of the potential transformer for interrupting the primary winding current at frequencies above the AC line frequency.

Abstract: A three wire power supply circuit is provided comprising a circuit for monitoring the integrity of the ground connection of the power supply circuit. A circuit element is provided in the line-to-ground current path which conducts when current flows in the line-to-ground current path and is nonconductive when the ground connection is poor or absent. A microcontroller monitors the output of the circuit element and operates a buzzer or a light emitting diode to indicate when the ground connection is poor or absent.

Abstract: A system for selectively providing power from a power source to a load to operate in an area for at least one occupant comprising a processing device for controlling the opening and closing of a relay connected between the load and the power source for energizing the load, and a sensor for detecting the presence of an occupant in the area. The processing device is programmable to close the relay in response to an output signal from the sensor for a period of time that can be of fixed duration, or a duration that is dynamically and automatically determined using sensor data relating to measured time between successive, detected occupant movements. In addition to a daylight inhibit function, the system is provided with color indicators and a tone generator to indicate various operating conditions and to guide a user entering selected system parameters, among other features.