Abstract: A programmed PWM controller for controlling an inverter is provided which includes memory means for storing a plurality of drive data words representing a pulsewidth modulation sequence, each drive data word including a driveword and a drivetime word, the drivewords being used to operate the inverter; first digital means for selectively retrieving each of the plurality of drive data words from the memory means according to the pulsewidth modulation sequence in response to a next drive data word request signal; and second digital means governed by the drivetime word for generating the next drive data word request signal.

Abstract: An inverter circuit for providing an AC driver voltage for a capacitive load from a DC input voltage. The circuit uses a pair of balanced transistors supplying a split primary winding of a transformer, a feedback winding thereof being coupled thereto to supply a feedback signal to the transistor inputs. Resistors are used to optimize inverter efficiency by adjusting transformer saturation and the DC bias of the drive transistors. A capacitor is connected across the two primaries to provide harmonic suppression an aid in starting the inverter. A second capacitor, connected from base to collector of the transistors opposite the transistor with DC bias being introduced, provides suppression of undesirable high frequencies which will occur if this capacitor is not present. The AC output is supplied from the secondary winding of the transformer.

Abstract: A reference voltage generator which compensates for temperature and V.sub.CC variations includes a constant current source and a MOS P-channel transistor. The constant current source provides a constant current over a wide range of V.sub.CC that corresponds to biasing a p-channel transistor in a region where its resistance is constant. The output of the current source is supplied to the P-channel transistor, which is in saturation. The constant current provides a constant voltage drop across the P-channel transistor. Hence, a stable reference voltage is generated. Temperature compensation is provided by biasing the P-channel transistor to saturation and supplying a constant current that the corresponds to biasing a p-channel transistor where the resistance is substantially constant over a temperature range. The current causes a voltage drop across the P-channel transistor to maintain a stable reference voltage.

Abstract: Disclosed is a power system for use with a computer, the power system having incorporated in it circuitry for automatically varying the supply voltage output to the computer system based upon the magnitude of the current being supplied to the computer by the power system. Also included in the computer system is a variable frequency clock circuit, the frequency of which changes based upon the supply voltage produced by the power system. This permits, during computer system operation where low voltage and low clock speeds will be sufficient to provide the performance needed, achievement of a power saving since both the voltage and frequency at which the system operates is reduced, thereby markedly reducing the power consumption.

Abstract: Precise CMOS bandgap voltage and current references which uses the difference of MOS source-gate voltages to perform efficient curvature compensation are proposed and analyzed. Applying the developed design strategies, bandgap voltage references (BVR) with a temperature drift below 10 ppm/.degree.C. and a power supply drift below 10 ppm/V can be realized. For bandgap current references, both drifts can be under 15 ppm. An experimental BVR chip shows an average drift of 5.5 ppm/.degree.C. from -60.degree. C. to 150.degree. C. and 25 .mu.V/V for supply voltages between 5 V and 15 V at 25.degree. C. Due to novel curvature compensation, the circuit structure of the proposed references is simple and both chip area and power consumption are small.

Abstract: An inverter apparatus for a battery-powered vehicle drive which is selectively operable in either a normal drive mode or an alternative battery-charging mode. In the drive mode, the inverter functions to invert DC from the vehicle's on-board storage batteries to a polyphase AC to power the vehicle drive motor. In the battery-charging mode, the inverter draws charging current from an external energy supply source and supplies it to the battery as a DC charging current. The apparatus is usable with external energy supply sources varying widely in voltage and frequency.

Abstract: An integrated current generator circuit operates in conjunction with a known reference voltage and internal and external reference resistances. The current generator circuit includes three operational modes. In the first operational mode, the reference voltage is impressed upon the internal reference resistance to generate one or more relatively inaccurate output currents. In a second operational mode, the reference voltage is impressed upon an external reference resistance to generate one or more highly accurate output currents, even if an internal ESD resistor is used, or if the bonding pad has high series parasitic resistance. An alternative voltage sensing path is included to ensure the accuracy of the reference current. In a third operational mode, the reference voltage is again impressed upon the internal resistance, with the corresponding node voltage being connected to an external integrated circuit bonding pad.

Abstract: A method and apparatus for a circuit physically realizing a virtual ground function producing a virtual ground voltage halfway between the supply and common voltages and having improved accuracy and stability is described. A stable bias current source is coupled to a precision resistor voltage divider network, which is used as a voltage reference generator to produce a virtual ground voltage of a precise value. This reference voltage is coupled to an operational amplifier configured in a unity gain configuration. The circuit thus created offers numerous advantages over the virtual ground circuits in use in the prior art. An integrated circuit implementing this circuit is described, and alternative packaging embodiments are disclosed. Other embodiments are also disclosed.

Abstract: A controller for controlling currents in an AC line connected to the controller is capable of causing the controlled current to assume any pre-determined magnitude and wave form. The pre-determined AC magnitude and wave form need not be of the same frequency or wave form existing at AC power lines connected to the controller. The controller uses the voltage at the AC power lines and an additional DC voltage as two sources of power to control the current in an inductor connected in series with the AC lines. A plurality of electronic switches are arranged so that at any instant in time, closing of appropriate switches will apply either the line voltage, or the sum of the line voltage and the DC voltage, or the difference between the line voltage and the DC voltage to the inductor. This causes the current of the inductor to increase or decrease at a rate determined by the net applied voltage.

Abstract: A circuit arrangement, which includes a switched-mode power supply energized by a source and which is controlled by a control circuit. The switched-mode power supply supplies the control circuit with energy during operation. The circuit also comprising a starter circuit for applying a supply current to the control circuit when the arrangement is put into operation. A particularly simple and inexpensive construction is obtained in that the starter circuit comprises a capacitive voltage divider which is fed directly by the source and is provided with a tapping wherefrom the supply current is derived via a rectifier element.

Abstract: A method and apparatus for a circuit physically realizing a virtual ground function and having improved accuracy and stability is described. A stable bias current source is coupled to a bandgap reference generator and resistances to produce a virtual ground voltage of a precise value, this voltage is then coupled to an operational amplifier configured in a unity gain configuration. The circuit thus created offers numerous advantages over the virtual ground circuits in use in the prior art. An integrated circuit implementing this circuit is described, and alternative packaging embodiments are disclosed. Other embodiments are also disclosed.

Abstract: Disclosed is an a.c. electric railway power distribution system comprising an a.c. busbar having at least first and second a.c. busbar sections electrically isolated by a non-energized busbar. Each of a.c. busbar sections is capable of having at least one electric train electrically connected thereto as the train moves along a railway track. A first single phase a.c. power supply is operably connected to the first a.c. busbar section and a second single phase a.c. power supply is operably connected to the second a.c. busbar section. An a.c. to d.c. electronic power converter is provided having an input operably connected to the first a.c. busbar section, and having an output operably connected to a d.c. busbar. A d.c. to a.c. electronic power converter is also provided having an input operably connected to the d.c. busbar and having an output operably connected to the second a.c. busbar section.

Abstract: A power supply for generation of a mainly sinusoidal output voltage, the magnitude and frequency of which are adapted for driving of main power-operated apparatuses. The power supply includes means (10) for generating a DC voltage, a DC/AC converter (18) including controlled semiconductor switches (19,20,21,22) and an electric control device (30) for emitting to the semiconductor switches suitable commutating signals according to a predetermined program to keep the switches closed and open, respectively, such that the desired waveform for the output voltage is achieved. Sensing of a parameter associated with the load current of the power supply is associated with the load current of the power supply is provided and cooperates with the control device (30) such that upon the load current exceeding a predetermined value the commutating signals are cancelled. The commutating signals are thereafter reconnected after a period of time which is considerably less than half the period of the output voltage.

Abstract: An ozonator power supply including a step-up transformer having one end of its primary winding connected to one side of an AC supply, its other end connected to the other side of the AC supply via a pair of switches connected in antiparallel, and a controller for providing switching pulses to said switches for making them conductive during variable portions of alternate half cycles of the AC voltage provided by said supply. An inductor is included in the circuit with the primary or secondary winding of the transformer that resonates with the capacitive impedance of an ozonator, for presenting a substantially non-reactive load to said AC supply.

Abstract: An inverter device for supplying a stable, high power-factor input current while restraining higher harmonics to be low is provided by a simple circuit structure in which a pulsating DC voltage supplied through a power circuit is provided to a smoothing condenser, a direct current is provided from the smoothing condenser to an inverter circuit section, and an input current path is formed from the power circuit through an impedance element to a switching element of the inverter circuit section and to part of an oscillation circuit.

Abstract: An output voltage of an A.C. power source is input to an frequency converter and the frequency thereof is increased. A plurality of high voltage transformers of small capacity each of which has a secondary winding of a small number of turns and which are connected in parallel with one another are connected to an output terminal of the frequency converter. Outputs of the high voltage transformers are respectively connected to high voltage rectifier circuits. Outputs of the high voltage rectifier circuits are serially coupled, the output voltages thereof are added together, and the addition result is applied to an X-ray tube. Combinations of the high voltage transformers and the high voltage rectifier circuits are molded into units one or a preset number at a time with solid insulating material including gel insulating material.

Abstract: Disclosed is a new Transformerless Power Conversion System (TPCS) that allows a direct voltage step-up or step-down of DC or AC power without the use of magnetic core transformers. The operation is accomplished with solid state switching devices, capacitors, preferentially air core inductors and a switch control system.The conversion and step-up from AC to DC and the inverse process can be implemented with high efficiency and without the generation of harmonics. The transformer elimination in conjunction with high inversion frequency operation results in a low weight system without transformer core losses and third harmonic generation. For high ratio DC to DC transformation the TPCS transports the input charge directly to the output without requiring an AC link. The three distinct operations of charging, transformation, and energy discharge are typically in sequential order and allows a complete isolation between the input and output power grids.

Abstract: An improved phase-controlled power control apparatus includes a semiconductor switching element for varying the effective power delivered to a load from the power lines. The conduction angle of the semiconductor power switch element is varied from a nominal angle to compensate for changes in power line voltage and for changes in load current. The amount of load current flow is continuously compared to the power line voltage to detect any overcurrent condition, even very close to the zero-crossing of the power line voltage. The shape of the transition from load current on to load current off (or vice versa) in controlled to minimize audible noise from the load. The load current can be shared between a plurality of compatible power control sections.

Abstract: According to this invention, a power supply apparatus includes a first power supply unit, a second power supply unit, and an interlocking starting circuit. The first power supply unit has a first power supply terminal connected to a power supply, a first converter for converting a voltage of the power supply terminal into a predetermined voltage, and a switch for connecting/disconnecting the power supply through the first power supply terminal. The second power supply unit has a second power supply terminal connected to an output of the switch and a second converter for converting a voltage of the second power supply terminal into a predetermined voltage. The interlocking starting circuit is connected to the output of the switch and interlocks and starts the first and second power supply units.

Abstract: A power supply system for powering a plurality of loads. The system includes a plurality of energizeable power supply circuits each associated with one of the loads for supplying power thereto in response to a power supply circuit control signal. An actuable power sharing arrangement is connected to all of the power supply circuits to facilitate sharing of power among the power supply circuits in response to a power sharing control signal. In addition, a control circuit generates the power supply control signals to individually controlling energization of each of the power supply circuits and the power sharing control signal to maintain the power sharing arrangement in an actuated condition when the power supply circuit control signals are controlling all of the power supply circuits to be energized, and otherwise maintaining the power sharing arrangement in a de-actuated condition.