Abstract: A fluorescent lamp operating circuit includes a high frequency electronic ballast circuit for providing a controlled output to a fluorescent lamp load. A control signal is detected from the power line carrier which includes binary data indicative of the illumination level desired. The control signal comprises a multi-bit binary signal which is detected by the control circuit and used to control the frequency of the power supply circuit so that the fluorescent light illumination level may be dimmed over a wide range.

Abstract: A transfer compensation circuit for use in a standby A-C power system which compensates for the transient in system output voltage which occurs when the system transfers from the conventional A-C input voltage to the standby power system. The compensation is dependent on the total load on the system at the instant of transfer. The total load includes both the external load connected to the system load and the battery in the standby supply if the system normally functions to provide charging current to that battery.

Abstract: A continuously operating standby A-C power system which uses a single loop responsive to the system's input and output A-C voltages, the voltage of the battery included in the standby portion of the supply and the amplitude and frequency of the input A-C voltage for controlling the phase relationship between the input and output voltages. When the input A-C voltage is acceptable in both amplitude and frequency, the loop is closed. When the voltage becomes unacceptable, the loop opens. When the voltage returns to acceptability after a period of nonacceptability, circuitry is included in the system for slowly closing the loop.