Raytheon Company

Spellman High Voltage Electronics Corporation

Reliance Electric Company

Derek Chambers

Richard H Baker

A Leonard Harley

Hugh C Masterman

Dee Wang

S Merrill Skeist

Robert O Pedersen

Andrzej Bortkiewicz

David L Chu

A variable output induction motor drive system for use with a polyphase variable output alternating current motor including a rotor and stator to drive an operating load such as an automotive vehicle, the variable output induction motor drive system comprises a sine wave current generator operatively coupled to a direct current power source to receive direct current therefrom and to generate a variable sine wave current and operatively coupled to the polyphase variable output alternating current motor to selectively feed the variable sine wave current thereto and a sine wave current control coupled between the sine wave power current generator and the polyphase variable output alternating current motor to monitor the operating parameters of the polyphase variable output alternating current motor and to control the amplitude and frequency of the variable sine wave current fed from the sine wave current generator to the polyphase variable output alternating current motor to control the output torque and speed thereof.

Variable output induction motor drive system

An inverter system having two resonating current sources which are resonant at the same frequency. The currents of the two sources are combined. At low power levels, the currents are substantially out of phase and the frequency is adjusted. At intermediate power levels, the currents are adjusted in phase and the frequency is fixed. At high power levels, the currents are substantially in phase and the frequency is adjusted.

Multi-mode control systems for high-frequency resonant inverters

A DC to N phase AC converter, where N is an integer greater than 2, includes a DC source having first and second terminals for deriving equal amplitude opposite polarity DC voltages, a series resonant circuit, and N output terminals, one for each phase of the converter. The series resonant circuit is selectively connected in series with the first and second terminals and the N output terminals for an interval equal to one half cycle of the resonant circuit resonant frequency, so that current flows between a selected one of the first and second terminals and the resonant circuit and a selected one of the N output terminals during the interval. The resonant circuit current is zero at the beginning and end of the interval. A capacitor shunting each of the output terminals has a value relative to the capacitance of the series resonant circuit such that the voltage across each output terminal remains approximately constant between adjacent exchanges of energy between the resonant circuit and the output terminal. The selective connection is in response to a comparison of the actual voltage across each of the N output terminals and a reference voltage for each of the N output terminals. The comparison controls when the flow of current between the selected first and second terminals and the selected output terminal via the resonant circuit begins. The frequency of the AC voltage developed across the N output terminals is much less than the resonant frequency of the circuit.

Series resonance charge transfer regulation method and apparatus

An inverter system having a plurality of resonating current supplying stages connected in parallel, all resonant at the same frequency. The rate at which the stages operate is controlled by a feedback circuit responsive to the load output. The rate is maintained above the audible range for all but small total current values. Should the rate tend to vary outside a predetermined range, a different combination of stages is switched in. The stages supply currents which are binary weighted.

High-power, high-frequency inverter system with combined digital and

A high power factor AC to DC power supply having a high frequency pulse producing circuit comprising an inductor supplied with rectified raw AC power through a semiconductor switch which provides dynamic power factor correction by maintaining the width of the on-times of the switch substantially constant throughout each cycle of the input AC power. The peak energy stored in the inductor during the on-times are a function of the amplitude of the instantaneous voltage of said rectified AC power, so that each time the switch is turned off, the output pulse of current supplied to the load by the inductor has a time duration which is a direct function of the instantaneous voltage value of the rectified AC power. The output load has a filter whose time constant is greater than a cycle of said rectified AC power, and the average on-time of said switch is varied over a number of cycles of said AC power to regulate the output voltage of said supply.

Digitally controlled power supply

A high voltage power supply system particularly adapted for rapid switching of high voltage applied to an anode of a beam penetration color cathode-ray tube. Energy for making the rapid transition between voltage levels is stored in two energy storage inductors, one for upward transitions and the other for downward transitions. When it is desired to change the voltage applied to the cathode-ray tube, the appropriate one of the storage inductors is coupled through a controlled switch to the anode causing the voltage applied to the anode to change at a rapid rate. The voltage rises until the desired voltage level corresponding to a desired output color is reached at which time the switch is turned off and the storage inductor recharged. A tracking high voltage supply maintains the anode at the predetermined voltage level once that level has been reached. Gain compensation is applied to the deflection amplifiers within the system so that patterns displayed upon the cathode-ray tube have a constant size independent of the voltage applied to the final anode of the tube.

High voltage power supply system

A marine radar system having a constant brightness display presentation upon all range settings and with independent switched power supplies for both the MTR and indicator units. The switching frequencies of the power supplies are independent from each other and those of the data clocks and PRF with the switching frequencies of the power supplies being intermediate those of the data clocks and PRF. Means is provided for switching the bandwidth of the system in accordance with the range setting. A digital STC circuit and a North stabilization device are also provided.

Marine radar system with independent switched power supplies

Switched high voltage power supply system

A synchronized power supply for use with display systems and data processing equipment in general in which information is displayed on a screen such as a cathode ray tube in which the power supply is synchronized to the display such that internal synchronization is maintained regardless of variation in external synchronization. A unique converter arrangement transfers regulated power to the loads at high efficiency such that both improved power supply and display operation result.

High efficiency low-loss power supply

A display and power supply system in which the power supply uses a switching frequency which is higher than the highest linear deflection rate used in a cathode ray tube display device supplied by the power supply and in which the frequency of the power supply and the information repetitively displayed on the display are synchronized to eliminate interference of the power supply frequency with the display characteristics.

Power supply with voltage protection circuit

A preregulator power supply having drive and control circuits which are isolated or floating alternately from the input and output leads to permit direct coupling to the power switching regulator device without requiring isolation devices such as transformers or optical isolators. This is achieved by an added series winding on the output choke, the common junction of which is connected to the output of the switching regulator and also forms the return lead for the floating drive and control circuits, while the added winding provides a sample output voltage for comparison by the floating drive and control circuits to control the width of pulses fed to the switching regulator device. A free-wheeling diode is also connected from the output of the switching regulator to an output terminal to maintain current in the choke during the OFF cycle of the switching regulator and provide several isolated regulated voltages in windings magnetically coupled to the choke.

Switching power supply with floating internal supply circuit

A voltage subtracting diode which is utilized in the current limiting or current foldback section of the voltage regulator circuit of a power supply to offset the base-emitter voltage drop of a transistor in said regulating circuit and also to provide tracking of the base-emitter voltage of said transistor with temperature in order to stabilize the value of current limit operation and to permit accurate current limiting with a smaller value of resistance in the series pass current sensing resistor. The use of individual diodes for each pass transistor permits parallel stages of series pass transistors to be used without exceeding permitted limits in the event of a failure of one of the series pass transistors.

Current limiting circuit for voltage regulated power supply

A display and power supply system in which the power assembly uses a switching frequency which is higher than the highest linear deflection rate used in a cathode ray tube display device supplied by the power supply and in which the frequency of the power supply and the information repetitively displayed on the display are synchronized to eliminate interference of the power supply frequency with the display characteristics.

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Bedford, NH, United States of America

Derek Chambers