A redundant power supply system wherein the standby power supplies are maintained in a powered up state at all times by feeding back a difference signal which is indicative of the voltage difference between the output of the power supply and a further difference voltage. The further difference voltage is indicative of the voltage drop across a diode located between the output from the power supply and the load of the entire power supply system.
In a power supply device supplying, in parallel, power from a plurality of DC/DC converters to a common load, there is provided an output compensation circuit which is provided on an output side of each of the DC/DC converters and compensates for an output voltage drop due to a voltage drop developing across a diode for parallel operation.
A disturbance-limiting circuit for regulation equipment connected to an actuator controlling a process in which the actuator is controlled from a reference generator unit (1) via a plurality of regulator modules (3A, 3B, . . . , 3N) having their outputs connected to a common point (UP) so that the control value provided to the actuator at said point corresponds to the mean value of the respectively-provided voltages. The circuit is constituted by a voting circuit comprising modules (4A, 4B, . . . , 4N) each inserted between the output of one of the regulator modules and a corresponding respective resistor (RA, RB, . . . , RN), connected to the common point (UP). Each voting module includes an impedance adapter (7A) having its input connected to a regulator module and having its output connected to the corresponding respective resistor, said output is also connected via a resistor (9A) firstly to the input of the adapter via a clipping circuit (8A) and secondly to a point (UR) common to all of the adapters of the voting circuit.
A compensation circuit for a DC--DC converter having a low voltage output line and a plurality of high voltage output lines applied to a plurality of loads includes an adjustable impedance source connected to the low voltage output line. The impedance source generates a feedback control signal to the DC--DC converter used to control the transformer duty cycle. A sensing circuit is connected to the plurality of high voltage output lines for generating a control signal which represents variations in the output voltages of the high voltage output lines. The control signal is applied to the impedance source to thereby regulate the feedback control signal which in turn provides regulation for the high voltage output lines.
A second inverter portion having a similar configuration to a first inverter portion is connected in parallel with the first inverter portion which consists of an inverter circuit and an inverter driving circuit. If an inverter current detector detects abnormality of an electric current flowing through the inverter circuits in use of the first inverter circuit, use of the second inverter portion is allowed by switching a switch.
In a DC--DC converter circuit having a plurality of input terminals connected to a plurality of DC power supplies, and an output terminal, the DC--DC converter circuit includes a power supply selection section for selecting a DC power supply of lowest voltage on the condition that the voltage is not less than a predetermined voltage, and a step-down type of regulator section for converting the voltage of the DC power supply selected by the power supply selection section into a predetermined voltage lower than the voltage of the DC power supply selected by the power supply selection section, and outputting the converted voltage through the output terminal.
