Abstract: The integrable control circuit drives a semiconductor switch in a switched-mode power supply. The control circuit has a control unit for producing control pulses for the semiconductor switch based on a variable oscillator signal. A duration of the individual control pulses depends on a first control signal and on a second control signal. In addition, a measurement system produces the second control signal in dependence on a load current of the semiconductor switch. A power regulation system that receives the oscillator signal produces a third control signal and supplies the signal to the control unit. The third control signal is inversely proportional to the square root of the oscillator frequency. In this way, it is possible for the power output of the switched-mode power supply to remain constant independent of the oscillator frequency.

Abstract: Intelligent power supplies to provide power to electronic devices in a manner the avoids causing a power supply circuit fuse to blow or breaker to trip are disclosed. The power supply circuit includes a power supply control device that determines whether supplying power to an additional electronic device would exceed the capacity of the circuit and cause the fuse to blow or the breaker to trip. The power supply control device communicates with electronic devices via a power control interface to determine the power requirements of the electronic devices. Power is supplied to the devices that can be supplied without causing the fuse to blow or the breaker to trip. Power is not supplied to the devices that would cause the fuse to blow or the breaker to trip.

Abstract: A switch mode power supply (SMPS) and method are provided. In particular, the present invention provides an SMPS in which data is encoded by manipulating voltage pulses on a primary side. The manipulated voltage pulses are then transferred over a transformer to a secondary side. Secondary side pulses generated in response to the primary side pulses are sensed and decoded by a detector. The present invention allows data to be transferred from the primary side to the secondary side without affecting output voltages.

Abstract: Methods and apparatus are disclosed for reducing output ripple voltages in bandgap voltage reference circuits. Ripple rejection circuitry is connected to a supply voltage and a first control signal, such as from an amplifier. The ripple rejection circuitry provides a second control signal representative of a difference between the supply voltage and the first control signal. The second control signal is then used to generate a reference voltage output. The incorporation of the supply voltage component in the second control signal operates to reduce or suppress the effects of power supply ripple on the bandgap voltage output.

Abstract: The present invention provide systems and methods for reducing a reverse recovery current through a body diode in a synchronous switching transistor. An inductor is coupled in the commutation path of the body diode of the synchronous switching transistor. The inductor slows the rate of increase of the reverse recovery current to reduce avalanche effects in the synchronous switching transistor. This reduces the peak reverse recovery current through the body diode of the synchronous switching transistor when the body diode commutates, thereby reducing power dissipation in the main switching transistor. An inductor may be coupled to both switching transistors so that power dissipation is reduced if the regulator is operated as a buck or boost regulator. A diode and a reverse recovery switcher may be coupled to the inductor to transfer energy in the inductor back to the input or output capacitor after the body diode commutates.

Abstract: When a main switching transistor of a zero voltage switching power supply is conductive, a voltage is developed in a current sensing resistor coupled in series with the transistor. The voltage in the current sensing resistor is coupled to a control terminal of a comparator transistor. During a given conduction interval of the main switching transistor, the comparator transistor is turned on when the current sensing resistor voltage is sufficiently large to turn on the comparator transistor. An output of the comparator transistor is coupled to the control terminal of the main switching transistor for controlling the turn off instant of the main switching transistor on a current pulse-by-current pulse basis. A resonant voltage pulse developed at a main current conducting terminal of the main switching transistor is capacitively coupled to the control terminal of the comparator transistor for maintaining the comparator transistor turned on, during a transition interval of the resonant voltage pulse.

Abstract: A voltage source circuit adapted to provide a regulated output voltage independent of variations in an input voltage and having an input node adapted to receive an input reference current and an output node adapted to provide a definable voltage output. The circuit comprises a control element adapted to provide an output signal to the output node, an impedance being driven by the output signal of the control element, and a sensing element having a current mirror adapted to sense the current flowing through the impedance, and to provide a feedback signal. The control element is responsive to the difference between the feedback signal and the input reference current, thereby providing a regulated voltage output.

Abstract: The present invention provides a device and method for protecting the motor of a hermetic refrigeration compressor. The device comprises a motor, input power lines, and a motor protector connected to the input power lines to control the power to the motor. The motor protector includes a microprocessor, an input power measurement device, and a switch means for controlling the connection of the power lines to the motor. The input power measurement device includes a motor power input signal to the microprocessor. The microprocessor includes memory having instructions for storing an operating input power limit range based on the torque limits of the motor and for comparing the power input signal to the operating input power limit range of the motor. The microprocessor controls the switch means to open when the input power signal is outside of the operating input power limit range of the motor.

Abstract: The internal supply voltage generating circuit includes a level trimming circuit for regulating a first reference voltage and generating a predetermined second reference voltage, and an internal reference voltage generating circuit connected to the level trimming circuit, for generating internal reference voltages using the predetermined second reference voltage. The internal supply voltage generating circuit prevents the circuit area from increasing, reduces a variation in a load when regulating a feedback voltage, and generates a plurality of highly accurate internal supply voltages.

Abstract: A power supply unit having: transformer (2) with primary winding (2p) connected to D.C. power supply (1); switching element (3) connected to the primary winding (2p) of the transformer (2); forward controller (4) for controlling the switching element (3); rectifier element (5), choke coil (7), switching element (19) and smoothing circuit (8), all connected in series between secondary winding of the transformers (2) and output terminal (9); rectifier element (6) connected in parallel with the rectifier element (5) and the secondary winding; and switching element (21) and smoothing circuit (22) connected in series between an output terminal of the rectifier elements (5) and output terminal 24. The forward controller (4) controls the switching element (3) responsive to an output voltage of the smoothing circuit (8). Divider control circuit (23) controls the switching element (21) responsive to an output voltage of the smoothing circuit (22).

Abstract: A ripple-mode controller provides reliable operation in multi-phase power supply circuits, over a variety of operating conditions. Cross-phase blanking allows the controller to preserve the desired phase relationship between the switching pulses its provides to the different output phases, and permits the controller to operate each output phase at nearly 100% duty cycles. Active current sharing compliments blanking operations by adjusting the width of switching pulses the controller provides to one or more of the output phases based on detecting load current imbalances between the different output phases. With active current sharing, the controller prevents one or more output phases from carrying excessive portions of the load current. Further complimenting its operation, the controller may include virtual ripple generation to increase the noise immunity of its ripple-mode regulation.

Abstract: A parallel operation-type uninterruptible power system capable of preventing one of uninterruptible power systems from being extremely increased in load sharing ratio without having to operate each uninterruptible power system while watching operation of the remaining uninterruptible power systems. The uninterruptible power systems each are constituted by an inverter circuit and an inverter circuit control device. The inverter circuit control device includes a PWM control signal generating means. The PWM control signal generating means generates a PWM control signal so as to gradually reduce an output voltage of the inverter circuit as supply active power increases and until a judging means judges that the supply active power has reached a predetermined level and so as to reduce the output voltage at a reduction ratio increased as compared with before to keep it from falling into an overload condition when the judging means judges that the supply active power has reached the predetermined level.

Abstract: A surge arrester having electrical connections to a source of power and to electrical ground is retrofitted with a spark gap assembly to improve performance of the surge arrester. This is accomplished by a providing a spark gap module including at least one spark gap assembly sealed within a housing, disconnecting an electrical connection of the surge arrester, and connecting the spark gap module between the electrical connection and the surge arrester.

Abstract: A reference current source includes at least one first voltage-controlled current source, at least one second voltage-controlled current source, and an addition unit. The first voltage-controlled current source includes: at least one first control voltage source providing a first temperature-dependent control voltage, at least one first MOS transistor having a process gain, and an output providing a first current that is dependent on the control voltage and on the process gain of the first MOS transistor. The second voltage-controlled current source includes: at least one second control voltage source providing a second control voltage, at least one second MOS transistor having a process gain, and an output providing a second current that is dependent on the second control voltage and on the process gain of the second MOS transistor. The addition unit provides a reference current from the first current and the second current.

Abstract: A silicon controlled rectifier (SCR) serving as an electrostatic discharge (ESD) protection device having a vertical zener junction for triggering breakdown. The SCR includes a p-doped substrate having an n-doped well, spaced-apart p+ and n+ doped regions for cathode connection formed within the n-doped well, and spaced-apart p+ and n+ doped regions for anode connection formed with the p-substrate external to the n-doped well. The SCR further includes a vertical zener junction situated between the anode n+ doped region and the n-well. The vertical zener junction has a p+ doped region sandwiched between two n+ doped regions. The n+ doped region of the vertical zener junction closest to the n-well may extend at least partially within the n-well, or be totally outside of the n-well.

Abstract: A semiconductor apparatus includes positive and negative side conductors for bridge-connecting semiconductor switches, constituted to a wide conductor, and laminated by sandwiching an insulator between them. A semiconductor apparatus includes positive and negative side conductors extended from its case, and an electrolytic capacitor connected to the extension portion of the positive and negative side conductors. A power converter uses the semiconductor apparatus.

Abstract: An architecture for a post regulator control circuit that utilizes an advance trigger signal to trigger the post regulator ramp. This advance trigger signal anticipates the beginning and end of a power cycle, and can be used to drive all of the secondary rectifier switches with optimal timing to minimize both cross conduction and body diode conduction. The architecture can be used to cascade an arbitrary number of post regulators. The present invention provides to the auxiliary outputs the full range of regulation available to the main output even in light load conditions. Rather than sensing the beginning or end of the power cycle, the present invention anticipates the beginning and end of the power cycle using the pulse train generated by the feedback loop for the main output. This allows the circuit to prepare the switches for the beginning of the power cycle and avoids problems encountered with inherent propagation delays in the circuit.

Abstract: A semiconductor electric power converter in accordance with the present invention comprises an arm consisting of an IGBT, a capacitor connected between a collector and a gate of said IGBT, and a gate circuit connected to the gate of said IGBT for controlling the switching operation of said IGBT, wherein a plurality of said arms connected in series are connected in parallel and each midpoint of said arms connected in of series is connected to a load. Thereby the impedance between the gate terminal of the IGBT and the gate circuit is decreased when the gate voltage is higher than the gate voltage command value or the impedance between the gate and the emitter of the IGBT is decreased when the collector voltage is high so that an electric charge stored in the gate is rapidly discharged.

Abstract: The present invention provides to a method and apparatus for minimizing or preventing negative current build up in DC-DC converters with synchronous rectification. The method turns the first synchronous rectifier off when the negative current is present in the first secondary winding and the first synchronous rectifier is on, and turns the second synchronous rectifier off when the negative current is present in the second secondary winding and the second synchronous rectifier is on.

Abstract: The voltage supply provides voltages to an electronic circuit requiring at least two different supply voltages. A plurality of standby supply voltages with different levels are obtained from the highest supply voltage with the aid of a voltage divider.