Controlled switched bridge-based power reconfiguring apparatus

Claim 1

A power manipulating apparatus for manipulating an input source of power having a voltage of a predetermined amplitude characteristic into an output power source having a voltage of a different predetermined amplitude characteristic, and operable in a selected one of two states, in a first operating state the input power is characterized as being directed current and the output power is characterized as being alternating current, and in the second operating state the input power is characterized as being alternating voltage and the output power is characterized as being a unipolar voltage, the apparatus comprising: a plurality of switching bridge means coupled in series, each bridge means comprising two input terminals coupleable to an input power source, two output terminals on which an output power source is generated, and four switch means for coupling selectively each of the input terminals to each of the output terminals; means for generating, for each bridge means, first and second control signals representative of a predetermined pattern of switching of the associated four switch means, each of the first and second control signals being associated with two of the switch means and having two states; the control-signal-generating means comprising means for generating a signal indicating a pattern corresponding to the desired output power characteristic, and means, responsive to the pattern-indicating signal, for storing a plurality of patterns of switching of the switch means and outputting the first and second control signals in the pattern determined by the pattern-indicating signal; the pattern storing and outputting means comprising an addressable memory means storing the patterns of control signals at predetermined addresses, and the pattern-indicating signal means converting the existing output terminal voltage level into the pattern-indicating signal as a digital signal in the form of an address corresponding to the predetermined pattern of control signals; the means for generating the first and second control signals being responsive to a third control signal having two states, with all of the first and second control signals having a third state when the third control signal is in a first state whereby all of the switch means are open, and the first and second control signals are in the first and second states as determined by the means for generating the first and second control signals when the third control signal is in the second state; means controllable for generating the third control signal in either the first or second state; switch driver means responsive to the first and second control signals and coupled to each of the switch means, with the switch driver means associated with a first switch means opening the first switch means and the switch driver means associated with the second switch means closing the second switch means when the corresponding one of the first and second control signals is in a first state, and the first switch driver means closing the first switch means and the second switch driver means opening the second switch means when the corresponding one of the first and second control signals is in the second state; at least one switch driver means comprising a diode means for coupling the corresponding control signal to the associated switch means, with each control signal being coupled to the anode of the diode associated with a first of the pair of switches to which the control signal is coupled, and coupled to the cathode of the diode associated with the second of the pair of switches to which the control signal is coupled, whereby the same control signal forward biases one of the diodes and reverse biases the other of the diodes when in the first state, and reverse biases the one diode and forward biases the other diode when in the second state; means for sensing the voltage amplitude at both sets of terminals; and switch means operable for selecting the voltage amplitude sensed at the output terminals corresponding to the operating state of the apparatus, the first and second control signal generating means being responsive to the sensed voltage amplitude for generating the pattern of states of each of the first and second control signals; the pattern-indicating signal generating means being responsive to the output voltage amplitude existing on the output terminals for varying the pattern-indicating signal in a manner reducing any difference between the existing voltage amplitude and the predetermined voltage amplitude on the output terminals.