Abstract: A power conversion system is described which includes a power input for accepting a waveform at a given power level and frequency, and a power output for providing an output waveform at a second given power level. A DC to AC converter accepts a waveform based on an input wave form from the power input and converts the waveform to an AC waveform having a frequency at least approximately an order of magnatude higher than the frequency of the input waveform for application to a DC to AC converter output. An AC converter accepts the output waveform from the DC to AC converter output and provides a converted waveform from an output of the AC converter to the power output. A coupling device operates at the frequency of the converter output for coupling the output of the DC to AC converter to the AC converter.

Abstract: An uninterruptible power supply, with passing neutral, comprises a twin step-up chopper whose input is connected to a battery and to a rectifier circuit connected to the mains power system. The twin step-up chopper comprises a positive step-up chopper supplying a first output voltage between a positive DC output and neutral, and a negative step-up chopper supplying a second output voltage between a negative DC output and neutral. The control circuit of the twin step-up chopper comprises means for regulating imbalance between the output voltages of the positive and negative step-up choppers, suitable both for operation on the mains power system and for operation on the battery.

Abstract: The invention relates to the encapsulation of integrated circuits, and more particularly encapsulation in a multi-layer ceramic case. In order to permit the disposition of chips of variable size on a monolithic chip (22, 24, 26) reception site (23, 25, 27) without the risk of having excessively long connection wires between the chip and the conductive regions (44) surrounding the reserved site, it is proposed according to the invention to cover the chip-reception site with a number of mutually insulated conductive contacts which can serve as soldering relays for these connection wires (80, 90, 100). If the chip is large (chip 24) it is bonded or soldered to these contacts; if it is small (chip 22) it is surrounded by relay-contacts.

Abstract: The present invention converts an alternating current input into a direct current output by switching a current load at high speeds to create a voltage envelope having a maximum allowed voltage and a minimum allowed voltage. Complementary switching elements are employed to take advantage of both the positive and negative portions of an AC cycle. Load switching is arranged so that the current vector which represents the load is nearly coincident with the voltage vector which represents the power source. The system can operate in an open loop mode at a constant frequency, in a closed loop mode, or in a hysteresis mode. During open loop operation, the voltage envelope is not rigidly defined as the switching frequency remains constant. During hysteresis mode control, the voltage envelope remains fixed and the current switching frequency varies.