Abstract: A system (10) and method (100) for connecting and synchronizing a supplemental power supply (10) and a power grid. The present invention detects current feedback signals ia and ib and grid phase voltage input signals Ua—g, Ub—g, and Uc—g for controlling and synchronizing the three-phase output voltages Ua—p, Ub—p, and Uc—p, of the supplemental power supply (10) with the power grid. The method (100) of the present invention detects the three-phase voltages of both the supplemental power supply, Ua—p, Ub—p, Uc—p and the power grid Ua—g, Ub—g, Uc—g, and converts the detected voltages into components Ud—com, Uq—com on a d-q plane.

Abstract: A blank formed from electrically conductive sheet material defines a continuous conductive path which includes two terminal ends and at least three loops disposed along the path. The blank is foldable at preselected folding locations on the path to position the loops in overlying relation to one another, and the blank is preferably formed with the loops disposed along the conductive path in substantially the same plane. The blank is used to form a multi-turn planar winding for a magnetic device such as, for example, an inductor or transformer which may be incorporated into electrical circuits such as power supplies. The planar magnetic device provides a low overall volume and profile, as well as a substantially higher volume or surface area of conductive material per turn of the winding compared to conventional wire or etched windings to provide a higher current carrying capacity and fewer turns compared to conventional windings.

Abstract: A method and apparatus for determining accurate stored energy values and effective DC bus voltage values for a voltage source inverter. The technique includes the determination of an effective DC bus voltage for the VSI based on an output voltage and the modulation index of the VSI. Further, an estimated power flow can be integrated to obtain an estimated stored energy, which can then be used to determine the effective DC bus voltage of the VSI. The disclosed technique is accurate in both transient and steady-state conditions, and reduces the effects of long term error accumulation.

Abstract: A electric power conversion unit generates a DC output according to a pulse signal from a PWM unit. An A/D conversion unit converts the output voltage from the electric power conversion unit into digital data. A digital filter amplifies the difference between the digital data output from the A/D conversion unit and a reference value. A pulse width computation unit computes the on-time of a pulse signal provided to the electric power conversion unit based on the output from the digital filter. The on-time is written to an on-time register. The PWM unit generates a pulse signal according to the cycle set in a cycle register and the on-time written to the on-time register, and provides the signal to the electric power conversion unit.

Abstract: An exchanging converter includes a zero-voltage switching control circuit, which drives an output voltage filter capacitor to partially feed back storage energy to an input side thereof by means of the operation of a transformer (or storage inductor), and provides a complementary driving signal to switches in the exchanging converter when the switches reaching a zero-voltage switching control condition, so as to control turn off or turn-on time of the switches, enabling the switches to repeat the switching operation at zero-voltage again and again.

Abstract: Uninterruptible power supplies (UPSs), power conversion apparatus and power conversion methods are provided which may improve phase regulation of polyphase AC voltages in the presence of load imbalances. According to one embodiment, a UPS includes a DC voltage generating circuit that produces a DC voltage. A space vector domain controlled inverter couples the DC voltage generating circuit to an AC load, and produces a polyphase AC output voltage at the load by sensing a plurality of voltages at the load, transforming the plurality of sensed voltages according to a space vector (d-q) transformation to produce an output space vector, generating an error space vector from the output space vector and a reference space vector, and selectively coupling the DC voltage generating circuit to the load responsive to the error space vector. In this manner, a voltage control loop is closed in the d-q domain, which may improve per-phase regulation of the polyphase AC output.

Abstract: An electrical circuit provides a fixed frequency switching regulator, having improved dynamic response, and a low count of external discrete elements. The circuit can be used at 100% duty cycle and does not require a minimum load or the components usually found in such circuits for compensation. A current source is used to charge a timing capacitor. A comparator is used in conjunction with a hysteresis circuit so that as the timing capacitor is charged the voltage on one input of the comparator rises until reaching a set input voltage level whereupon the timing capacitor is discharged to ground. A PWM latch logic element is used to control output to a control switch, a FET, so that positive going output pulses are received at an output terminal. A divider network between the output terminal and the timing capacitor along with a switch controlled by the PWM latch element are used for slope compensation for maintaining operational synchronization to the oscillator.

Abstract: A switching flyback regulator circuit for providing a plurality of regulated DC voltage power supplies. The flyback regulator circuit includes a primary inductive element coupled in series with a first switch to turn charging current flow through the primary inductive element ON and OFF. A first secondary inductive element having a first end coupled to supply a first power source. A second secondary inductive element has a first end coupled to produce the second power source, and a second end coupled to a second switch to turn current flow through the second secondary inductive element ON and OFF. The first secondary inductive element and the second secondary inductive element are magnetically coupled to the primary inductive element.

Abstract: There is provided an inverter apparatus islanding operation detecting method capable of surely detecting an islanding operation with a simple construction. A distortion for causing a variation in an output frequency of an inverter apparatus in an islanding operation stage is applied to an inverter output waveform. With this arrangement, even when the inverter apparatus is disconnected from an AC power system in a state in which a power factor of a load impedance is proximate to one, a frequency variation is generated in an inverter output, thereby ensuring detection of the islanding operation.

Abstract: An uninterruptable power supply controlled by a digital signal processor. The digital signal processor periodically senses an input current, an input voltage, a battery current, a battery voltage boost circuit, first and second DC bus voltages, an output current and an output voltage. The digital signal processor controls an AC to DC conversion unit, a battery charger, a battery voltage boost circuit and a DC to AC inverter via an inner current loop and an outer voltage loop. The digital signal processor calculates the inner current loops each predetermined time interval and calculates the outer voltage loops every two predetermined time intervals. The digital signal processor preferably alternately senses a first group of signals consisting of the input voltage, the input current, the output voltage and the output current and a second group of signals consisting of the battery voltage, the battery current, the first DC bus voltage and a second DC bus voltage.

Abstract: An inverter apparatus operatable over an extended output frequency range having an increased upper limit with error contained in the output voltage being suppressed by eliminating dispersions of PWM pulse signals. A PWM command pulse signal and an output voltage detection signal derived from the output of the inverter are compared straightforwardly with each other for determining difference therebetween on the basis of which error contained in the inverter output voltage is canceled. An isolation device for isolating electrically a low-voltage-rated control circuitry and a high-voltage-rated main circuitry from each other is inserted between a PWM command pulse signal generating circuit and a pulse width correcting circuit.

Abstract: A multi-motor drive in which the resonance existing between one or more output filter capacitors of a current source inverter and an a.c. induction motor is reduced. The inverter features a switching pattern generator which controls the power switches of the inverter based on a reference current. A control loop, connected to the switching pattern generator, measures the load current or voltage and generates a nominal reference current based on an error therein; determines a damping current based on the voltage at the terminal; and determines the reference current supplied to the switching pattern generator by subtracting the damping current from the nominal reference current. The invention essentially simulates the use of a physical damping resistor connected in parallel with each output filter capacitor, but without the corresponding energy loss.

Abstract: An induction furnace having a voltage source series inverter, a load circuit having a combination of an induction coil and a resonating capacitor bank, and control circuitry to phase lock the inverter frequency to the natural resonant frequency of the load. The capacitor bank can be divided into two groups, one across the output of the inverter and the other in series with the load. This arrangement allows for the division of the inverter voltage across the furnace coil according to the ratio of the two capacitances. The inverter uses pulse width modulation and is buffered from the load circuit by means of a small series connected inductor. Additionally, the system can have a common power supply system that supplies power in any desired proportion to a plurality of induction furnaces.

Abstract: A series-resonant power converter (10) featuring a tap winding (106) on a transformer (100) that is coupled to a resonant capacitor (124) in a resonant tank circuit (122). An output voltage is taken at a secondary (104) of the transformer (100) via a rectifier (110). A control circuit (140) is coupled to the output voltage to monitor the output voltage with respect to a reference to determine load conditions and to generate a control signal representative thereof. An energy recirculation circuit (180) is coupled to the control circuit (140) and to the voltage source (12) and comprises a switch (186) coupled to the tap winding (106) of the transformer (100).

Abstract: The power converter of this invention accomplishes zero voltage switching at both turn on and turn off transitions of four primary switches (220, 224, 228, and 232). A pair of coupled inductors (242 and 244) serve as both energy storage devices and isolation mechanisms. The stored energy in the coupled inductors (242 and 244) is used to drive the resonant transitions. The availability of stored energy in a coupled inductor for driving a switching transition is dependent on the timing of secondary switches (250 and 252) whereby the turn off of the secondary switches is delayed until the transition of the primary switches is complete. The power converter behaves as a pair of interleaved coupled inductor buck converters with oppositely directed magnetizing currents. During a first half cycle, while one inductor is coupled to the output, the other uncoupled inductor behaves as a current source, setting the primary winding currents for both inductors equal to the magnetizing current of the uncoupled inductor.

Abstract: A switching regulator (18) for use in a switching power supply (10) receives a feedback signal and provides a gate drive signal. The switching regulator enables the gate drive signal once at any point during a cycle of an oscillator signal by setting a first latch (74) upon receiving a non-asserted feedback signal. Setting the first latch triggers a pulse generator (78) to generate a pulse signal. The first latch is not reset until the end of the cycle of the oscillator signal. Therefore, the pulse generator can generate only one pulse per oscillator cycle. The pulse signal sets a second latch (80) that enables the gate drive signal. The switching regulator disables the gate drive signal by resetting the second latch. A power transistor (20) conducts an inductor current through the primary winding of the transformer (16) in response to the gate drive signal.

Abstract: A switching power supply is provided which is capable of supplying a stable voltage to a control circuit with high precision so as to enable an electronic part that does not have a high voltage tolerance to be used in the control circuit, and which enhances efficiency by providing a circuit configuration with a reduced power loss. The auxiliary power supply circuit of the switching power supply is configured such that, to a primary power supply, a series circuit including a first resistor, a voltage element, and a Zener diode; and a series circuit including a second resistor, a first transistor, a second transistor; and a control circuit of a switching element, are connected in parallel to each other. The input terminal of the first transistor is connected to the connection point of the first resistor and the voltage element, the input terminal of the second transistor is connected to the connection point of the voltage element and the Zener diode.

Abstract: A voltage source supplies power to a ring laser gyro and includes a pulse width modulator that charges an output capacitor network. An apparatus connected to the pulse width modulator assumes control so that the pulse width modulator continues to produce output pulses despite exposure to radiation.

Abstract: A system for conserving power and reducing heat generation, and a method of operation thereof, that turns off an analog-to-digital converter during e period of time of non-data acquisition is disclosed.

Abstract: An inverter includes a first switch to disconnect an output of the inverter from any device connected thereto, a second switch to disconnect and connect an input of the inverter from direct current fed to the inverter, and a discharge device to discharge any residual charge on a large capacitor. The inverter further includes a voltage sensor to measure input DC voltage to the inverter, a current sensor to measure input DC current to the inverter and a data recorder to provide a current voltage trace to provide a current-voltage curve tracer to provide current-voltage properties of the solar array to which the inverter is attached. The inverter is capable of reproducibly operating at the same point on a module IV curve for a given set of temperature and irradiance conditions.

Abstract: A switched mode power supplier having an improved power factor, that is to say a reduced harmonic load on the mains comprising a switch mode power supply with a reduced harmonic load on mains, comprising a mains rectifier being coupled to a charge capacitor and to a series circuit, the series circuit comprising a decoupling element, a primary winding of a transformer, a switching transistor, and an energy storage capacitor coupled in parallel with the primary winding and the switching transistor, with the voltage thereacross being a smoothed DC voltage, the charge capacitor being further coupled to a tap of said primary winding via a second series circuit comprising an inductor and a diode, and the inductor and the diode being connected via a second diode to a point with a fixed voltage.

Abstract: A series-resonant power converter (10) comprising a transformer (100), a resonant tank circuit (120) having a piezo-electric crystal (122) as the resonant element and a series-connected resonant capacitor (124). First and second switches (132 and 134) are connected to the transformer (100) and are driven by voltages at windings of the transformer so as to alternately turn on. The piezo-electric crystal (122) self-oscillates to store and release energy and thereby charge and discharge the capacitor (124). Moreover, as a result of the self-oscillation of the resonant circuit (120), the switches (132 and 134) are alternately driven in synchronism with the charging and discharging cycle of the capacitor (122) through windings of the transformer (100). No additional switching circuitry is needed to achieve proper oscillation of the resonant tank circuit (120).

Abstract: For use with a flyback converter having a modulator for providing a main switch control signal thereto and main and cross-regulated output circuits, the cross-regulated output circuit subject to ringing and resulting voltage excursion, a voltage excursion controller and a method of operating the same. In one embodiment, the controller includes: (1) a delay circuit, coupled to the modulator, that generates a delay signal based on the main switch control signal and (2) an auxiliary switch, associated with the cross-regulated output circuit, that receives the delay signal and opens to isolate at least a portion of the ringing within said cross-regulated output circuit.

Abstract: A switching flyback regulator circuit for providing a plurality of regulated DC voltage supplies, wherein one of the regulator circuits includes a saturable reactor for regulating one of the output voltages. The flyback regulator circuit includes a primary inductive element coupled to a first switch to turn charging current flow through the primary inductive element ON and OFF, a first secondary inductive element having a first end coupled to supply a first power source and magnetically coupled with the primary inductive element, and a second secondary inductive element magnetically coupled with the primary inductive element. The second secondary inductive element has a first end coupled to produce the second power source and a second end coupled in series with the saturable reactor and a second switch to control current flow through the second secondary inductive element.

Abstract: An inverter power supply device designed to supply power to a resonant circuit, includes a generator, having at least one switch series-connected with the resonant circuit and a freewheeling diode parallel-connected with the switch, the switch being controlled by a periodic signal with a frequency known as a working frequency. The device furthermore includes first device providing a measurement of the instantaneous current flowing in the resonant circuit; second device to deduce the maximum current (I.sub.max) from the instantaneous current; third device to deduce the current known as the switching current from the instantaneous current, this switching current being the current for which the switch or the freewheeling diode that is associated with it becomes conductive (I.sub.commut); first control device for the switch, receiving the maximum current(I.sub.max), the switching current (I.sub.

Abstract: After starting the input of a switching signal to a booster circuit whose boosting rate is changeable in accordance with the duty ratio of the inputted switching signal and calculating the output power of an inverter circuit, which is connected to the subsequent stage of the booster circuit, from the output current of the inverter circuit, the target voltage after boosting by the booster circuit is obtained based on the output power. If the actual output voltage of the booster circuit is lower than the target voltage, the duty ratio of the above switching signal is increased, and if higher, the duty ratio of the above switching signal is decreased.

Abstract: A noise suppression circuit for use with a DC/DC converter having an output and an input responsive at least in part to the output of the converter is provided. The noise suppression circuit includes multiple parallel feedback loops, wherein the first feedback sets the steady state nominal output voltage, the second feedback loop prevents the output voltage from exceeding a predefined high voltage level, and the third feedback loop prevents the output voltage from decreasing below a predefined low voltage level. In some embodiments, the first, second, and third feedback loops comprise a operational amplifier, a diode, and an internal feedback loop, wherein the internal feedback loops of each of these loops share a common node. The common node configuration provides the circuit with quick transitions between output voltage states and dynamic regulation of the DC/DC converter output voltage.

Abstract: A power supply and method of operation thereof. In one embodiment, the power supply includes: (1) a primary side power switch, (2) an isolation transformer having a primary winding coupled to the primary side power switch, the primary side power switch conducting intermittently to transfer current from an input of the power supply to the isolation transformer, (3) a secondary side power switch, coupled to a secondary winding of the isolation transformer, that is operable to conduct within a conduction period of the primary side power switch to transfer current from the isolation transformer to an output of the power supply, a portion of the current being contained within the power supply during a nonconduction period of the secondary side power switch and (4) a capacitor, coupled to the secondary side power switch, that, circulates the portion toward the output during the nonconduction period.

Abstract: A switched bridge circuit includes a low voltage to high voltage interface which selectively controls an input to a high side switch. A controller compares the voltage across the interface, the state of the high side switch, and the output of the circuit. If hard switching is detected by the controller, it latches the voltage across the interface thus keeping the high side switch on to allow the hard switching to occur. If soft switching is detected, the high side switch is kept off. A source follower is used to drive the high side switch so that the circuit output follows the interface output thereby avoiding oscillation. A falling edge detector for the output of the circuit uses the inherent parasitic capacitance of a high voltage device which also forms a bootstrap diode. When the output drops, the parasitic capacitance feeds a resistance which causes a driver to actuate. A second falling edge detector uses the inherent parasitic capacitance of the level shifter switch which is another high voltage device.

Abstract: An AC-DC power supply system for receiving a three phase mains supply and outputting a transformed DC supply. The power supply unit has a rectifier circuit (30) providing an output to a three phase inverter circuit (40) to generate a pseudo AC three phase output of higher frequency than the AC supplied to the rectifier circuit (30). A three phase transformer (60) receives the pseudo AC three phase output and transforms the output to a three phase rectifier circuit (70) to generate the output DC supply. The inverter circuit (40) provides a three leg bridge structure with each leg having a switching device one of which is used to provide a phase reference whereas the other two legs control the relative phase shift on each leg to reduce the phase shift relative to the phase reference on one leg and increase the phase shift relative to the phase reference on the other leg.

Abstract: The invention relates to a method and an arrangement for producing an operating voltage of a desired form. A high-voltage operating voltage of a desired form is produced by means of a DC-AC converter. The desired operating voltage is usually a sine voltage. The DC-AC converter is controlled by means of a pulse form control signal of a signal generator, the pulse width of the control signal being controlled by means of a pulse width modulator. To change the pulse width of the control pulses, the operating voltage of a desired form produced by means of the DC-AC converter is compared with a reference signal and a comparator is used for forming a difference signal. The difference signal is used for controlling the pulse width of the control signal of the pulse generator in order to produce the operating voltage of a desired form.

Abstract: A power supply device having a transformer for generating at least one output voltage supplied to an electronic apparatus with power saving mode includes: a switching circuit connected to the transformer, a reference signal generator for generating a reference signal having a first high frequency or a second low frequency according to whether the electronic apparatus is in a normal operation mode or a power saving mode, and a PWM control circuit for generating a PWM signal to control the switching operation of the switching circuit according to the reference signal and a feedback signal from the output voltage.

Abstract: A circuit for inhibiting a transition phenomenon in a power supply unit is disclosed. When the power supply mode is shifted, a transition phenomenon is made not to appear in the operating power supplied to the load. The circuit includes a microcomputer which judges as to the presence or absence of horizontal and vertical synchronizing signals supplied from the computer system so as to vary the power in a stepwise form when shifting the power supply mode. In accordance with control signals of the microcomputer, a feedback level adjusting section reduces the error detected voltage in a stepwise form when the power is fed back from a second rectifying section through an error detecting section to a pulse width modulator (PWM) control section. Therefore, in accordance with the stepwisely decreasing error detected voltage, the pulse width modulator (PWM) control section reduces its output signals in a stepwise form, so that the power supplied to the load can be reduced in a stepwise form.

Abstract: A power supply comprises a first coupled to receive AC mains power that provides a first power level, a second stage that receives the first power level and that provides a second power level, a third stage that receives the first power level that provides a third power level, and a pulse width modulated switching block comprising a first modulation input, a second modulation input, the first modulation input receives a signal indicative of a voltage, current or power at the second stage output and the second modulation input coupled to receive a signal indicative of a voltage, current or power at the third stage output.

Abstract: In a switching power source, an error signal indicating an error of an output voltage is applied to an insolation element whose input and output are insolated from each other, and an output of the insolation element is utilized to control a switching operation, thereby to stabilize the output voltage. The switching power source includes a power outage detecting section in which, when an input voltage of a switching circuit adapted to switch a current flowing in a primary coil becomes lower than a predetermined value, the level of the error signal is a limit level, and when the level of the error signal becomes the limit level, a power outage detection signal is produced.

Abstract: The chopping power controller reduces switching error due to the noise in the current detected signal. The chopping power controller includes a switching member (18a) for supplying power to an electric load (1a) and a current sensor (2) for detecting electric current flowing through the electric load (1a). The detected electric current is compared by a comparator (16a, 30a) to a target value. The output from the comparator is supplied to a filter (23) for outputting identical signal (k) as the comparator (16a, 30a) after the comparator (16a, 30a) keeps the same level signal for a period of time. The switching member (18a) is turned off when the detected electric current continuously exceeds the target value for the period of time set at the filter (23). The filter (23) may removes the noise which has a shorter period than that of the filter (23). In other words, the filter (23) removes high frequency noise from the comparator (16a, 30a) in order to turn off the switching member (18a) accurately.

Abstract: A switched-mode power supply comprises storage means (8) for the storage of state information relating to switching times of switching means of the power supply, which state information corresponds to a load level of the load (3). The power supply further comprises detection means (9) responsive to a change in the load level of the load (3) to supply a selection signal (10) to the storage means (8) for the selection of the appropriate state information.

Abstract: A voltage converter having a voltage intermediate circuit and an invertor connected to the output of the voltage intermediate circuit. The invertor produces a three-phase AC voltage at its output and is connected to the output terminals of the voltage converter by a filter arrangement. The filter arrangement includes a filter inductor connected in series with the output terminal and the filter capacitor connected between the output terminal and a common capacitor star point. Attenuation of the DC system is achieved by having the capacitor star point connected to the voltage intermediate circuit by way of an RC element having a capacitor and a resistor.

Abstract: An inverter control unit includes a variable-tap-added step-down transformer. A DC energy unit is connected to a DC side of an inverter unit for supplying or consuming effective power. A control circuit controls a variable tap of the variable-tap-added step-down transformer. The control circuit includes a calculating circuit for calculating an effective value of a system voltage. A setting circuit sets an effective value command value. A deviation calculating circuit calculates a deviation between the effective value and the effective value command value. A tap command circuit operated by the system voltage outputs a tap command value corresponding to the deviation. A tap change judging circuit determines whether an inverter current at least equal to a rated value is output with a change in the variable tap. A tap command circuit changes the tap command value on the basis of the determination of the tap change judging circuit.

Abstract: A hybrid standby power system for producing regulated DC electrical power, a method of producing such power and a telecommunications installation that employs either the system or the method. In one embodiment, the system includes: (1) a primary power input, couplable to a primary power source, that accepts primary electrical power subject to interruption, (2) a standby power input, couplable to a standby power source, that accepts unregulated standby electrical power and (3) a power converter, couplable to at least one of the primary and standby power inputs, including a rectifier that rectifies at least one of the primary and standby electrical power to provide unregulated DC electrical power and a DC--DC converter that converts the unregulated DC electrical power into the regulated DC electrical power.

Abstract: A power conversion apparatus has a voltage type power convertor, a power control circuit for outputting a first active power reference signal for the voltage type power convertor based on a power reference value Pref and a detection value P of a power detector, a DC voltage detector for outputting a second active power reference signal for the voltage type power convertor based on a DC voltage reference value Vdref and a detection value Vd of the DC voltage detector, and a gate control circuit for firing switching elements in the voltage type power convertor based on both first and second active power reference signals.

Abstract: A self-oscillation type signal converter includes a piezoelectric ceramic, four electrodes P.sub.A, P.sub.B, Q.sub.C and Q.sub.D, a load resistance R consisting of N parts R.sub.i (i=1, 2, . . . , N), N-1 terminals T.sub.i {i=1, 2, . . . , (N-1)} between two parts R.sub.i and R.sub.(i+1), two terminals T.sub.0 and T.sub.N, formed on the electrodes Q.sub.C and Q.sub.D, respectively, a switch, a vibration circuit connected between the electrodes P.sub.A and P.sub.B, and a rectification circuit connected between two of all the terminals T.sub.0, T.sub.i and T.sub.N, via the switch. The electrodes P.sub.A, P.sub.B, Q.sub.C and Q.sub.D are formed on four side surfaces A, B, C and D, of the piezoelectric ceramic, respectively. The load resistance R is connected between the terminals T.sub.0 and T.sub.N. The piezoelectric ceramic, the electrodes P.sub.A, P.sub.B, Q.sub.C and Q.sub.D, form a piezoelectric vibrator. When a high-frequency electric signal E.sub.IN with a voltage V.sub.IN is applied to the electrodes P.

Abstract: A power supply comprises a bridge rectifier with an input and an output, the input of the bridge rectifier coupled to an AC power supply signal, the output comprising positive and negative terminals; a first inductor comprises a first terminal and a second terminal, the first terminal coupled to the positive terminal of the output of the bridge rectifier; a first switch comprises a first terminal, a second terminal and a control terminal, the first terminal of the switch coupled to the second terminal of the first inductor, the second terminal of the switch coupled to the negative terminal output of the bridge rectifier and the switch being switched on and off at a first duty cycle according to a signal received at the control terminal; a first diode comprising an anode terminal and a cathode terminal, the anode terminal coupled to the first terminal of the switch; a first capacitor comprises a first terminal and second terminal, the first terminal coupled to the cathode of the first diode and the second term

Abstract: In order to provide an inverter apparatus and a solar power generation apparatus in which when a main AC power system (5) has suffered, e.g., a power failure, the operation mode of an inverter (2) in the tie operation with the main AC power system (5) can be easily and safely switched from the tie operation mode to the self-support operation mode, and electric power can be supplied to a load (4) directly using normal indoor wiring, the open/closed state of a switch (3) for opening/closing a connection between the output terminal of the inverter (2) and the main AC power system (5) is detected, and the self-support operation of the inverter (2) is started when the open state of the switch (3) is detected.

Abstract: An output voltage control apparatus for performing feedback control on an output voltage of an inverter which drives an AC machine. The output voltage control apparatus converts a command value for the output voltage of the inverter into a pulse density using a converter (PDM), and converts a detection value of the output voltage of the inverter into a pulse density using a .DELTA.-.SIGMA. modulation converter. The proportional control ability and integral control ability for the output voltage are realized by digital hardware including an up-counter, a down-counter and a shift circuit.

Abstract: An monolithic programmable dc--dc converter controller integrated circuit with a high speed synchronous controller and a 4-bit programmable DAC to provide an operating voltage to an external device such as a microprocessor in response to a code programmed in the external device. The 4-bit programmable DAC outputs a signal which is combined with a precise reference voltage to provide voltages to the external device in increments of 100 millivolts.

Abstract: Switched mode mains power supply unit having a transformer (Tr), which comprises a primary winding (L.sub.P) and at least one secondary winding (L.sub.S) as well as an auxiliary winding (L.sub.H), having a switch (S) controlled by a control circuit (A), by means of which switch the primary winding is connected to an input direct voltage (U.sub.E), having, connected downstream of the secondary winding, a rectifier (D1) together with a filtering means (C1) for producing an output direct voltage (U.sub.A) and having a regulator means (K1) for producing a first control variable (St1) for the control circuit (A) in dependence upon the deviation of the output voltage from a first set value (U.sub.Ref1), wherein the pulse duty ratio and/or the frequency of the control signal of the controlled switch depends upon the control variable, and also having an auxiliary rectifier (D2; Glr) connected downstream of the auxiliary winding (L.sub.H) in order to produce an auxiliary direct voltage (U.sub.

Abstract: An RCC system switching power source comprises a delaying capacitor C1 having one terminal connected to the base of a switching transistor Q3 and the other terminal connected to a primary side ground level IN-. The delaying capacitor C1 delays the rise of the base voltage of the switching transistor Q3 after the current of a secondary coil 7 becomes zero.

Abstract: An inverter-control device includes a subtractor for detecting an error between a waveform of a reference current signal generated in synchronization with a waveform of an inverter output current signal and the inverter output current signal, a delay portion for delaying by a prescribed time period a signal obtained by amplifying and removing high frequency component by filtering the error, an error waveform integrating portion for integrating the delayed signal f' output from delay portion, a proportional control portion for amplifying the error, and an adding portion for adding an error amplified signal output from the proportional control portion and an inverter driving waveform pattern output from the error waveform integrating portion.

Abstract: A PWM controlling circuit includes a signal generator and two PWM controllers. The signal generator comprises an oscillator, a plurality of inverters, and two RC delay networks. The oscillator and the inverters are composed of elementary elements, respectively, such as diodes, resistors, inverters and capacitors. The PWM controlling circuit in accordance with the present invention can be implemented with low cost, and the duty cycles thereof are not limited to 50%.