Abstract: A system for measuring available energy in a metal fuel cell is provided. The system comprises first componentry for measuring an electrical property of a mixture formed from one or more reaction products dissolved in a reaction medium. The electrical property may be such as to bear a known relationship with the concentration of the one or more reaction products. Using this known relationship, second componentry estimates the concentration of the one or more reaction products, and, responsive thereto, determines the available energy in the fuel cell.

Abstract: The present invention can be embodied in a power source having internal redundancy for allowing continued operation of a load such as an electric vehicle, as well as related methods. The power source comprises a first plurality of fuel cell stacks, a second plurality of fuel cells, and a third plurality of bypass devices. Each power converter can receive input electrical power from one of the fuel cell stacks and generates output electrical power at a predetermined output voltage. The power converters can be connected in series between terminals of the power source. Each bypass device can be coupled to one of the power converters for providing a current path if the power converter is unable to provide output electrical power. Each power converter can have selectable output voltages for increasing its output voltage if one of the power converters is not supplying power for the power source.

Abstract: A system for measuring available energy in a metal fuel cell is provided. The system comprises first componentry for measuring an electrical property of a mixture formed from one or more reaction products dissolved in a reaction medium. The electrical property may be such as to bear a known relationship with the concentration of the one or more reaction products. Using this known relationship, second componentry estimates the concentration of the one or more reaction products, and, responsive thereto, determines the available energy in the fuel cell.

Abstract: The present invention may be embodied in an apparatus, and related method, for monitoring an individual cell in a fuel cell in an electrical power source. The monitoring apparatus includes a plurality of individual cells, a first switch network, a capacitor, a second switch network, and a voltage measurement circuit. The plurality of individual cells electrically may be stacked in series. The first switch network is coupled between the plurality of cells and the capacitor for momentarily coupling a selected cell to the capacitor. The second switch network is coupled between the capacitor and the measurement circuit for momentarily coupling the capacitor to the measurement circuit for permitting measurement of the voltage across the capacitor for monitoring selected cells. The capacitor may be a floating capacitor that is electrically isolated from a reference voltage of the monitoring apparatus when not coupled by the second network to the measurement circuit.

Abstract: An AC power amplifier (50) with a pair of push-pull transistors (Q1, Q2) driving opposite sides (36, 38) of the primary winding of an output transformer (T1) controlled by a pair of variable duty cycle, pulse width modulated width trains (A, B) generated on the output of a pulse width modulator (26) controlled, in turn, through means of a wave shaping feedback system to cause the AC output at the secondary winding (20) to track the output of a precision reference sine wave oscillator (12) and through means of another feedback system for automatic DC compensation including a pair of CMOS analog switches respectively driven by the two pulse width modulated pulse trains (A on 28, B on 30) to produce a pair of feedback signals.

Abstract: A pulse-width ac voltage regulator that provides a precisely ac output voltage without the need for any inefficient protective circuitry for ensuring proper operation when it repeatedly switches between its two alternative operating modes. A transformer is arranged with a first winding connected between an input terminal and an output terminal and a second winding connected between one end of the first winding and a control terminal. A special switch assembly including four separate circuits, each having a series connected transistor and diode, is controllably switched such that the second winding is alternatively shorted or excited, to provide a stepped-up (or stepped-down) voltage out of the first winding. The transistors are controllably switched at a frequency substantially greater than that of the ac input signal and at a duty cycle selected to provide the desired ac output voltage.