Abstract: In connection with remote feeder devices it is often necessary to take steps not to exceed limit values, for example the maximally permissible contact voltage. Customary voltage limiters evaluate the voltage at the output terminals of the remote feeder device. The remote feeder current can be distorted by the evaluation. With the invention, a dynamic resistor (V1, V2) is provided at the base point of the voltage limiter (BU), which can be set in such a way that the voltage drop at the remote feeder current regulator (RI) can be compensated. The range of the remote feeding or the distance between the intermediate current regenerators can be increased by means of the steps of the invention.

Abstract: A vibratory device having a drive circuit for providing a highly regulated drive voltage/current to the vibrator. A DC voltage is derived from line voltage. A DC-to-DC converter steps up the voltage to at least the desired voltage for vibration. The stepped up DC voltage is provided to the vibratory coils through a path containing a switch. The switch is controlled by an oscillator which turns the switch on and off at a desired vibration frequency so as to provide an alternating current through the coil for generating the vibratory force.

Abstract: One of a plurality of image processing apparatus connected to an image processing system freely sets image forming conditions, such as recording paper size and enlargement/reduction magnification ratio, with regard to some or all of the other image processing apparatus, subsequently reads the image of an original by means of a reader, outputs image data indicative of the image read and transmits this image data to the other image processing apparatus. The image processing apparatus that has read the image of the original and the image processing apparatus that has received the image data output copies of the image of the original on the basis of the image forming conditions that have been set. Accordingly, it is possible to provide an image processing method and system in which a plurality of image processing apparatus are connected and identical images are outputted simultaneously from each of the apparatus connected.

Abstract: A switched-mode power supply circuit having an operating mode and a stand-by mode, includes a functional ON/OFF switch. The switched-mode power supply circuit includes a transformer and a controllable switch connected to a primary winding of the transformer for switchably connecting the primary winding to a source of d.c. voltage. In the stand-by mode, based on a detected voltage level at an input of a controller IC, the switched-mode power supply circuit is arranged to switchable connect the primary winding to the d.c. voltage source in bursts which occur at a low frequency. By switchably connecting this input to a power source for the switched-mode power supply circuit, the controller IC detects the absence of this power source, and turns off the switched-mode power supply circuit allowing a minimum current consumption by the switched-mode power supply circuit.

Abstract: A low power consumption input buffer is disclosed which exhibits reduced power consumption, especially that of a peak current consumed, to make a semiconductor chip (e.g., a memory device) operated in a more stable manner. The buffer employs a switching unit to block a current path so as to decrease current consumption. Noise due to a peak in the current during transmission of an input signal is decreased by using a higher resistance constantly turned-on transistor.

Abstract: A system to control the output voltage of a power converter in response to a specific load battery condition. The system contains a power converter, a TCMS interface attached thereto and a controller for selectively and/or adaptably changing the magnitude of converter output voltage. A control module is incorporated in the system to automatically change converter output voltage up or down in response to the load (input) voltage. The module contains a microcontroller to sense the battery (input) voltage process said input voltage with an analog-to-digital converter. The microcontroller is programmed to execute a series of routines to determine the proper charging voltage for the system. Thereafter, the control module communicates this information through the interface of the power converter to cause the power converter to charge at the optimum voltage. In the alternative, a plug-in component containing passive circuitry may be used to manually signal the power converter to charge at a predetermined voltage.

Abstract: In order to adjust the output voltage and output current of a galvanically isolated switched-mode power supply, on the primary side there is formed an auxiliary voltage (15) proportional to the secondary voltage, and said auxiliary voltage is studied by means of a window comparator, so that when the auxiliary voltage is within the reference window, there is applied fixed power adjustment, and when the auxiliary voltage falls outside the reference window (>max, <min), the quantity of electric power fed in by the isolation transformer of the primary side is restricted. Most advantageously the auxiliary voltage is formed by means of an auxiliary coil (12b) contained in the isolation transformer, and the reverse threshold voltages of two zener diodes represent the limit values of the reference window.

Abstract: To improve the power conversion efficiency of a power circuit provided with a power-factor improvement converter and reduce the size, weight, and cost of the circuit, the power-factor improvement converter according to the invention is provided at a stage in front of the switching power circuit, in which a self-excited current resonant switching converter with a simple circuit construction is provided and the switching voltage thereof is fed back to the rectifying path via series resonant circuits so as to improve the power factor.

Abstract: A system interconnection generator comprising a power converting unit for converting solar energy into AC power by using a voltage chopping waveform, the ON duty of which is adjusted, thereby to supply the converted AC power to the system for a commercial AC power source. The distortion of the current waveform of the AC power supplied from the system interconnection generator to the system is detected to correct the ON duty of the chopping section after 360 degrees of the chopping section, in accordance with the distortion which has been detected.

Abstract: A multiple stage sequential synchronous regulator including multiple switch stages activated in a sequential manner to reduce the frequency, stress and power loss per stage. In the preferred embodiment, each stage is implemented using buck regulator topology including an inductor and two synchronous switches, preferably comprising MOSFETs. A sequential logic circuit asserts corresponding enable signals to activate each of the stages one at a time in sequential manner. Each stage also receives a pulse width modulated (PWM) signal for activating the first synchronous switch during a power phase and then activating the second synchronous switch during a flux reversal phase for the enabled stage. The time sharing of multiple stages reduces the average current per stage and allows increased utilization of the switching parts per stage. Thus, the typically large and expensive power inductors and switches are replaced with significantly smaller, lighter and cheaper components.

Abstract: A controller circuit for controlling and continuously varying the average value of discontinuous current pulses in a step down switching regulator operating in discontinuous conduction mode effects improvements in efficiency and output ripple of the switching regulator.

Abstract: A boost converter employs an isolated active snubber to reduce the losses caused by the reverse-recovery characteristic of a boost rectifier and the turn-on discharge loss of the output capacitance of the boost switch. The losses are reduced by inserting the primary winding of a coupled-inductor in the series path of the boost switch and the rectifier, to control the rate of current change (i.e., the di/dt rate) of the rectifier during its turn-off, and to create the conditions for zero-voltage turn-on for the boost switch. The energy from the inductor, after the boost-switch is turned off, is delivered to the output via the secondary winding of the coupled-inductor which is connected in series with a clamping capacitor and an auxiliary switch to form an isolated active snubber. The same technique can be extended to any member of the PWM-converter family.

Abstract: Run/standby switching including switching to standby upon excessive current loading are provided in a switched mode power supply useful as an auxiliary power supply in a television. A switching controller IC is coupled between a primary transformer winding on the rectified raw B.sup.+ input voltage and ground. A switching transistor is coupled to the control input of the controller and is biased by the raw B.sup.+ input voltage for pulling down the control input. A run/standby control circuit and an overcurrent protective circuit disable the switching transistor during run mode operation and enable the switching transistor upon an overcurrent fault. The switched-mode power supply is further provided with a quick-reset capability to enable the power supply to consistently provide output voltages which are within nominal output voltage levels despite rapidly repeated dislocations in the operational mode of the apparatus.

Abstract: A band-gap reference voltage generator comprises an operational amplifier comprising a first input and a second input, the first input being coupled to a first feedback network and the second input being coupled to a second feedback network both coupled to an output of the operational amplifier providing a reference voltage. The first feedback network contains an emitter-base junction of first bipolar junction transistor and the second feedback network contains an emitter-base junction of second bipolar junction transistor. A selectively activated current supply supplies a bias current to the operational amplifier, the current supply being deactivatable in a substantially zero power consumption operating condition for turning the reference voltage generator off. A start-up circuit activated upon start-up of the reference voltage generator for a fixed, prescribed time interval forces a start-up current to flow through the first bipolar junction transistor means.

Abstract: A soft start pulse width modulation integrated circuit having a reduced number of external connection terminals, a single one of which transmits the soft start signal superimposed upon an external sync signal. The soft start pulse width modulation integrated circuit includes a comparison voltage signal generating circuit, a soft start and external sync generation circuit, a comparator, a triangle signal generator and a pulse width modulator. The voltage level of a comparison voltage signal is increased over time in response to a feedback signal. A DC voltage signal is generated having a voltage level which increases over time but at a lesser rate than the comparison voltage signal and is superimposed with an external sync signal. The superimposed signal is compared with a reference signal and the resulting compared signal determines a triangular signal generated therefrom which has one of two different oscillation modes: a variable natural mode, and a regulated synchronized mode.

Abstract: A band-gap reference voltage source comprises a first current branch including a first field effect transistor (T1); a second current branch including a second field effect transistor (T2); a reference resistor (RRF) arranged in series with one of the field effect transistors (T1, T2); and a voltage level shifter for coupling the backgates (BG1, BG2) of the field effect transistors (T1, T2) to the gates (G1, G2) of the field effect transistors (T1, T2), which reduces the gate-source voltages of the field effect transistors (T1, T2). As a result of this, the output voltage supplied by the band-gap reference voltage source can be lower than customary.

Abstract: The present invention relates to a method for controlling the power to be transferred via a mains inverter, the mains inverter (VVS) being arranged to transfer electric power in both directions between the n-phase AC main system (U) and the DC intermediate circuit (1).

Abstract: A high voltage generating device includes a charge pump generating high voltage by boosting a power supply voltage and supplying it to a load, a timer measuring activation time of the charge pump and outputting a signal after a prescribed time period, an A-D converter converting an output voltage of the charge pump into a digital value in response to the signal and outputting four bit binary data, and a current limiting circuit including four P channel MOS transistors connected in parallel between a power supply node and a drain of an N channel MOS transistor which has a gate receiving the digital value output from the A-D converter.

Abstract: An AC-DC converter for connecting an AC supply and a DC has a rectifier, and a harmonic correction circuit formed of (a) thyristor inverter legs connected at a common output point to form a Y switch, or separately at positive and negative terminals and (b) a voltage selection circuit for selecting a voltage derived from one of the positive and negative DC rails, or the AC lines, to control current shape and turn-off the thyristors. The thyristors are turned on by, and may also be turned off by, a controller. The voltage selection network may be a resonant circuit that uses ramping of the voltage at the outputs from the thyristors to turn the thyristors off or switches controlled by the controller.

Abstract: A line type modulator for modulating an RF power device in a medical linear accelerator is described. The modulator employs a low voltage DC power source and a flyback transformer. Current sensing circuitry senses current in the primary winding of the flyback transformer and generates a current sense signal indicative thereof. A solid-state switching stage is coupled between the DC power source and the flyback transformer which electrically connects and disconnects the DC power source and the primary winding in response to a control signal. Control circuitry coupled to the current sensing circuitry and the switching stage generates the control signal in response to the current sense signal. The anode of a charge diode assembly is coupled to the secondary winding of the flyback transformer. A delay element is coupled to the cathode of the charge diode assembly. A pulse forming network is coupled to the delay element and generates an energy pulse.