Abstract: A microwave oven uses a full wave full bridge inverter for supplying energy to a cooking magnetron by way of a power transformer. The inverter is controlled by a microprocessor which acts upon a control circuit having an oscillator. The control circuit provides gating pulses which are used to switch on FET switches in the inverter. The microprocessor stops and starts the gating pulses. The microprocessor may adjust the power of magnetron by turning the control circuit on and off for variable time intervals. Alternately, the microprocessor may control the power of the magnetron by changing the switching frequency of the inverter. The microprocessor is used in a filament standby mode to monitor the current in the magnetron's filament. In the filament standby mode, the inverter is operated at a lower than normal voltage such that the magnetron is not generating microwave power, but its filament is receiving sufficient current to warm it up, the current flowing through a filament winding of a power transformer.

Abstract: The invention relates to an AC voltage supplied rectifier circuit with a downstream smoothing capacitor. A prior art problem with this type of circuit was that the inductive impedance of the supply voltage caused a practically umdamped oscillation between the inductive supply impedance and the smoothing capacitor during start-up which caused the voltage to rise to about twice the stationary value. A rectifier circuit is provided which substantially prevents the over-oscillation having at least one controllable rectifier which brings the rectifier to a conductive state during the charging period of the smoothing capacitor over such a time that the output direct voltage of the rectifier circuit exceeds the momentary capacitor voltage by no more than a predetermined limited value.

Abstract: In a voltage-source inverter system, wherein the commutation between static switches in the AC/DC converter in the regenerative mode is forced by a GTO or transistor device in series with an auxiliary thyristor in order to bring the current path to zero, a reactor of large inductance is inserted for improved operation in the forward and regenerative mode, but an additional thyristor is converted in unparallel to such reactor in order to neutralize the inductance when bringing the current to zero in the regenerative mode, and such additional thyristor is turned OFF by natural commutation when the next converter static switch is coming ON.

Abstract: In a hybrid relay circuit for supplying current to a load with a AC power supply, an electromagnetic relay is provided and the contact thereof is connected in series to the load and the AC power. The electromagnetic relay is driven by a driving circuit in accordance with an input control signal, thereby switching the supply of current to the load.

Abstract: A switch-mode power supply includes the series combination of an inductor and a controllable switch adapted to be coupled to a voltage source for producing a succession of increasing and decreasing ramp currents through the inductor. The average value of the ramp currents is controlled by a feedback loop. A second controllable switch arrangement is coupled for causing the current leaving the inductor to recirculate through the inductor during those intervals in which the second switch is conductive. An integrator is coupled to the inductor for integrating ramp current from the inductor during those intervals in which the second switch is nonconductive, for generating load voltage. A second feedback arrangement senses the load voltage and controls the average conduction of the second switch to control the load voltage. In one embodiment, an inverter receives ramp current from the inductor and generates alternating current, which are transformed and rectified before application to the integrator.

Abstract: A full-color copying machine copying color originals in colors as they are. A full-color copying machine in which a photosensitive member carrying multi-colored visible images obtained based on a color original is formed into belt, and the photosensitive belt is looped over between copying process stations.

Abstract: A circuit for reducing peak current in dependence on line voltage in a blocking oscillator-switched power supply, includes a transformer having a primary winding and a control winding, an electronic switch connected in series with the primary winding, and a control circuit supplied by the control winding for controlling the electronic switch, the control circuit including a pulse processing stage addressed by rectified a-c line voltage fed into the primary winding, a start-up stage, and a variable voltage coupling stage coupling the pulse-processing stage to the start-up stage.

Abstract: An inverter control apparatus contains digital phase-locked loop oscillators, in order to achieve a synchronization with a reference frequency of a commercial power supply. The inverters are activated by outputs from programmable dividers for frequency-dividing the output pulses from the digital phase-locked loop oscillators. The frequency-dividing ratio of each of the programmable dividers is changed in accordance with the deviation of the active output powers of the inverters.

Abstract: A bridge rectifier comprised of four passivated silicon diode chips coupled to convert an alternating voltage input to a direct voltage output includes four L-shaped leads each coupling the anode or cathode of one diode to either the same or opposite terminal of another diode. Each L-shaped lead includes transversely coupled first and second elongated, linear sections with the first sections of each lead forming either the AC input lines or DC output lines. The second section of each lead is coupled to either the anode or cathode of one of the diode chips, each of which includes a dielectric coated moat, or groove, around the periphery of one of its flat, generally rectangular shaped terminal surfaces which prevents charge migration on the edges of the chip and resulting leakage current.

Abstract: A power supply control is disclosed which performs in conjunction with an a.c. source as may be provided by a utility line input. This line input is directed through a converter which reflects or mirrors an a.c. signal into the line input mimicing it in all aspects except that of amplitude. The opposite side of the bi-directional device is coupled to a node connection which further is coupled to an energy reservoir present as a rechargeable storage battery. An output converter device serves to develop a desired a.c. output employing the energy at the node connection. Energy transfer into the node is provided by controlling the amplitude of the input converter such that it is slightly less than that of the input utility. The apparatus is modular in design such that it may assume a variety of configurations employing either a.c. or d.c. node connections.

Abstract: An off-line regulating power supply utilizes a regulating transistor which perates in a dissipative mode for only a portion of each half cycle of an input AC voltage in order to regulate an output voltage by truncating the input AC sinewave. This AC input signal is full wave rectified and coupled to a primary winding of a power transformer through the regulating transistor. One of a plurality of secondary windings is coupled to a voltage threshold detector which responds instantaneously to attainment of the threshold in each half cycle of operation to bias the regulating transistor from a saturated condition to an active dissipative impedance state which limits the output voltage to the threshold level. As the input AC sinewave peaks and declines in value, the regulating transistor is again biased into saturation when the voltage applied to the threshold detector drops below the threshold level.

Abstract: A traction power supply system in which one, two or three single-phase traction loads are supplied from a 3-phase high voltage system. Balancing of the load in each phase of the high voltage system and reduction of reactive currents in that high voltage system is achieved by simulating any further single-phase load or loads necessary to make the number up to three and providing individual controllable balancing circuits for all of the single phase circuits together with individual harmonic filters designed to include accommodation of the harmonic currents generated by the balancing circuits.

Abstract: A power supply circuit includes a battery power source connected by a switch to the input of a DC to DC converter. The output of the DC to DC converter is connected to a filter capacitor and a load. A crow-bar is connected to the input and the output of the DC to DC converter. The crow-bar shorts the output to ground to discharge the capacitor when the voltage at the input drops to a predetermined value.

Abstract: This patent presents a touch-responsive switch which incrementally varies AC voltage supplied to an electrical apparatus. The invention includes digital circuitry which compares a control pulse train with a touch affected pulse train to create a switching pulse. The switching pulse is synchronous with the line frequency and controls truncating of individual cycles of line power to regulate voltage applied to an appliance as a function of the number of times a touch plate has been touched. The switching pulse also provides on/off switching as one of the available incremental steps. The circuit components are incorporated in an interface assembly which connects the appliance receptacle to a source of AC voltage.

Abstract: An improved instrument for use with an electrochemical cell that provides a system having enhanced stability and increased bandwidth. The instrument includes a voltage to current converter which drives the cell. The current output of the voltage to current converter is linearly proportional to the differential voltage input. The voltage to current converter drives the cell in both the potentiostatic mode and in the galvanostatic mode of operation.

Abstract: A switched-mode power supply providing high speed switch operation and high efficiency is disclosed. Faster switch turn-off is accomplished by means of an additional primary winding in the power supply's converter transformer which causes switching current to be diverted from the switch element when the oscillating switch transitions to the cut-off state. More rapid switch turn-on is achieved by shunting current from the regulation circuit of the power supply during initial switch turn-on in providing the entire switch control output of a blocking oscillator to the switch element. Power supply regulation is provided by an optical link including a photodiode coupled to a secondary of the converter transformer and a phototransistor which controls the input provided to the switch by the blocking oscillator.