Contraves Goerz Corporation

Gerard A Gallagher

Kenneth R Wyman

A DC power supply is disclosed which returns excessive regenerative energy to the AC line. The regenerative power supply generates a DC bus voltage from an AC power line and regulates the maximum DC bus voltage by returning to the AC power line energy supplied through the DC bus from the load. A conventional full wave rectifier bridge is used to rectify the incoming AC power line voltage into a DC bus voltage. A capacitor is connected across the DC bus to dampen high frequency transient voltages which may be present on the DC bus voltage. In anti-parallel with each of the rectifying diode circuits is a power transistor which is controllable to allow current conduction in a direction opposite to its associated rectifying diode. Control circuitry, associated with each of the anti-parallel transistors, senses excessive DC bus voltage and initiates conduction of the transistor when the AC power line phases are at the correct potential for receiving the regenerative energy.

Regenerative DC power supply

A power processor having a switching type output is provided with protection against short circuit current flow. A transformer is provided with the primary windings connected in series with the main current flow path. The secondary transformer windings have a voltage signal induced therein which is indicative of a rapidly rising short circuit current flow. A threshold detector connected to the output from the secondary windings determines when the voltage signal from the secondary windings exceeds a predetermined value. The signal from the threshold detector is used to activate over current protection circuitry which shuts down the output switching devices and prevents the occurrence of large short circuit currents.

Short circuit protection for switching type power processors

A power processor having improved current monitoring constructed from a plurality of power output modules which can be added or removed as desired to change the power output rating. The electrical output of the individual power modules are removably attached to an output combining structure. The electrical connections to the output combining structure also provide mechanical support for the power output modules. The servo controller is constructed so that as additional power modules are added, each provides a predetermined proportion of the output power. That is, each module will add in a linear fashion to the total output capability of the amplifier. The disclosed modular servo controller includes an improved current sampling circuit. A feedback signal is derived from the power output modules to protect the servo controller. The protection of the power controller is one function of the feedback signal, in that, it limits the maximum current derivable from the controller under normal conditions. The primary function of the current feedback signal is to provide an error signal which when combined with the input command causes the current output to be properly metered to a load. The feedback signal can be obtained from only one of the output modules since load current sharing is provided in the paralleled output module to a degree sufficient to guarantee that sampling the current flow through one module produces a signal proportional to the actual total load current. Alternately, the feedback current signal can be obtained from a composite signal derived from individual signals from each module. A third way of obtaining the feedback signal is through a sampling of the combined output currents from each module.

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Pittsburgh, PA, United States of America

Gerard A Gallagher