Abstract: An emergency power supply including an input for connection to a power line, an output for connecting the input to electrical equipment so as to supply power thereto from the power line, a supplemental power supply connected to the output and adapted to supply power to the electrical equipment upon a power abnormality in the power line, an electrical energy storage means connected to the supplemental power supply and adapted to supply electrical energy thereto; and a circuit for detecting the abnormalities in the power line.

Abstract: An electronic appliance having a microcomputer, peripheral devices controlled by the microcomputer, a main battery acting as power source, and a backup battery for backing up the main battery. Checking is made of whether the main battery is loaded in the appliance or not and whether the output voltage of the main battery is above a predetermined voltage or not. When the main battery is not loaded or when its output voltage is below the predetermined voltage, the backup battery is made available for preserving information in the memory inside or outside the microcomputer in good order, with operations of the peripheral devices being restricted at such times. Further, the disclosed electronic appliance includes means to prevent malfunctioning of the microcomputer and the peripheral devices when a new main battery has been loaded in the appliance as replacement for an exhausted main battery.

Abstract: An inverter control system for selectively operating on one of an inverter and backup power source to supply a load current comprises a PLL circuit which includes an integrating amplifier and is operative to synchronize the inverter operation with the voltage of the backup power source. When the power supply to the load is switched from the backup power source to the inverter, a.c. switches for the switching operation are controlled so that both the backup power source and inverter are active simultaneously for a certain period, and during the parallel operation the integrating amplifier is supplied with a reference signal which operates on the inverter to increase its shared load current.

Abstract: A consumer electronics product such as a portable radio or combination radio/tape recorder having both primary and auxiliary loads is provided with power control apparatus for energizing both loads when connected to a source of a-c potential and energizing only the primary load when connected to a source of d-c potential. The control apparatus includes a solid state switching device in series with the auxiliary load, the switching device coupled to the output of the a-c source such that it is conductive only when a-c electric power is being supplied to drive the loads.

Abstract: The power supply system comprises three levels: a primary level (PRI), a secondary level (SEC), and a tertiary level (TER). The secondary level is constituted by power supply circuits (S1 to Sn) which provide galvanic isolation between the primary and the tertiary levels, and which provide at least one intermediate voltage at a fixed level relative to a system reference potential (point R). The tertiary level comprises chopper power supplies (RD), converters (CV), and inverters (OND) connected to user equipment (UT).

Abstract: Techniques are disclosed for supplying positive and negative voltages to electrical components in a system where power demand from the components needing voltage of one polarity is different from the power demand from components needing voltage of the other polarity. At least two batteries of substantially the same capacity are connected in series and used to supply the positive and negative voltages to the system components. In order to permit the batteries to be recharged simultaneously in series without damage to them the interconnection between the batteries and the loads are alternately reversed so that the batteries will discharge at substantially the same rate.

Abstract: An engine generator power supply system comprises a plurality of engine generators; a plurality of separate power feed lines for independently feeding power from respective engine generators to a plurality of loads respectively associated with the separate power feed lines; an electromagnetic contactor inserted in each of the power feed lines, the contactor being normally enabled for feeding power to the plurality of loads from one of the engine generators; and a controller for controlling such that the supply of power from a first engine generator to the plurality of loads is switched to the supply of power from a second engine generator to the plurality of loads at a predetermined time interval.

Abstract: An uninterruptible power supply utilizes a controlled ferroresonant regulator to derive a regulated DC voltage from a primary AC source. A reserve source of DC power is coupled to the output through a DC voltage regulator which is activated when the DC output voltage of the power supply drops below a predetermined threshold.

Abstract: A primary load, such as a conventional household light bulb, is series connected to a power source. The conventional light switch is replaced by a series connected circuit to the source and lamp. The circuit has an energy storage capacitor and a diode. A secondary load, such as an alarm, is coupled across the capacitor through an SCR (Silicon Controlled Rectifier). A sensing circuit, such as a smoke detector, is also connected across the capacitor and triggers the SCR upon detection of an alarm condition. A timing circuit is coupled between the SCR output and the diode to intermittently control the light bulb operation at a predetermined frequency upon smoke detection or other alarm. A switch selectively places in the circuit a neon night light or dimmer circuit for the primary load. In an alternative circuit the primary load is operated at near full power during periods of non-alarm.

Abstract: A control arrangement for a three-phase, uninterruptible power supply generates timing signals to drive the static switches of inverters located in each phase. This control arrangement precisely controls the phase differences of the inverter signals with relation to each other so that while the overall three-phase power supplied by the inverters is nulled, power circulation through the inverters compensates for unbalanced output loads thereby maintaining balanced phase angles between the output voltage and a balanced input impedance at the input of the power supply.

Abstract: A method and system for controlling peak electrical demand placed on a source of electrical energy by a plurality of electrical loads that include at least one electrical load of lower priority than at least another of the loads. Demand for electrical energy by the loads connected to the source of electrical energy is sensed and, in response to the sensed demand exceeding a predetermined value the loads are selectively disconnected from the source. Normally, all the loads are connected to the source in the absence of a sensed excessive demand condition. Therefore, all demand control is lost in the event of failure of the controller. Accordingly, the system senses an abnormal operating condition of the controlling system of the type that renders the selective disconnecting means inoperative to disconnect the loads from the source. The electrical load of lower priority is then disconnected from the source for the duration of the sensed abnormal condition.

Abstract: A NMOS transistor in the input current path of a PMOS current mirror amplifier senses any tendency to change of the voltage across a load driven by the output current of the amplifier. In response thereto, the NMOS transistor changes the input current of the amplifier to thereby vary its output current in a sense to maintain the voltage across the load constant.

Abstract: To prevent high-intensity-discharge (HID) lamps from extinguishing for prolonged periods due to a power interruption or an appreciable drop in line voltage, a rectifier-battery combination provides standby power for operating a high-frequency inverter. The output of the inverter connects to the HID lamps through impedance means which passes a greatly reduced high-frequency current as compared to the normal lamp operating current, in order to sustain the operation of the lamps at a very reduced power level. Upon restoration of the normal line voltage, the lamps again operate with normal power consumption. The same wiring can be used for both the normal lamp operating current and the high-frequency sustaining current or separate wiring systems can be used if desired. The high-frequency current can be supplied simultaneously with the normal operating current or the high-frequency current can be supplied only during periods of power interruption.

Abstract: Power is fed from a pair of power supplies to each one of a plurality of load circuits through a distributed power switch. A plurality of switch means are each associated with a respective one of the load circuits for connecting it to one of the power supplies in a primary manner and to the other power supply in a secondary manner. Upon failure of its primary source of power, each switch means is effective for automatically connecting its load circuit to its secondary source of power.