Abstract:
An inverter arrangement including controlled rectifiers, the inverter being supplied by a regulatable direct voltage supply which includes an on-off switchable element and a filter. A control circuit connected to the output of the supply generates and directs first control pulses to the switchable element, and a pulse generator also connected to the output of the supply generates and directs second control pulses to control the rectifiers in the inverter. The control circuit includes a step regulator having an amplifier, a feedback path and apparatus for producing an oscillation, the step regulator having the effect of altering both the frequency and the width of the first control pulses when the voltage at the output of the supply changes.
Abstract:
A three-phase inverter for producing a stepped voltage approximating to a sinusoidal form, and largely free of odd harmonics, wherein, for the purpose of producing each phase voltage a basic and two additional rectangular impulses are summed, the basic impulse being shortened in relation to a halfwave and occupying substantially the entire amplitude-time area of the phase voltage, and the additional impulses having a considerably smaller amplitude and shorter duration than the basic impulse. One of the additional impulses procedes and the other is superimposed on a basic impulse of the same polarity.
Abstract:
An electrical three-phase generator and motor control circuit. The generator is made of three alike wave-generating units in cascade each generating a respective trapezoidal wave corresponding to a respective phase of the generator. Each unit comprises a small detector in series with a control circuit varying the amplitude of the wave proportionately to a control voltage representative of and corresponding to variations of voltage from voltage sources and applied to a motor and an integrating circuit consisting of an integrating amplifier and an integrating capacitor and a double limiter in parallel therewith. The control voltage is developed by a voltage divider across the motor control circuit.