Abstract: A reference voltage circuit is disclosed that is independent of the voltage supply as well as substantially insensitive to process and temperature variations. The reference voltage circuit includes an intrinsic transistor circuit which includes a plurality of intrinsic transistors of equal size. The intrinsic transistor circuit is coupled to a current mirror circuit, and a plurality of threshold transistors. In so doing, a reference voltage circuit is provided that is substantially independent of process and temperature variations. In addition, by grounding the source connections of the plurality of threshold transistors, the reference voltage circuit output voltage also is substantially independent of supply voltage variations.

Abstract: A switched mode power supply is provided that has two output circuits one of which is directly regulated by control of the input switching device and the other of which is indirectly regulated. This indirect regulation is provided by means of an additional winding wound in common on an energy-storing magnetic core with windings of the first and second output circuits. The additional winding is connected between a lower-voltage one of the output circuits and the other, higher-voltage, output circuit such that when the lower-voltage output circuit is lightly loaded current can flow from this output circuit through the additional winding to the higher-voltage output circuit, this current decreasing as the loading on the lower-voltage output circuit increases.

Abstract: A soft switching device for electric power switching applications includes a switching element and a soft switching active snubber. The soft switching active snubber includes a capacitor, a rectifier and a soft switching active reset circuit. The capacitor connects in series with the rectifier and both of which connects across the switching element. The soft switching active reset circuit, connected across the rectifier as well as the capacitor, is responsive to a reset signal for active resetting of the capacitor within the normal switching cycle of the switching element. Energy absorbed by the capacitor is recovered to the input voltage source or to the load. This occurs contemporaneous with the power switching operation of the switching element. With the active snubber, soft switching is provided for both the switching element and a snubber switch within the active reset circuit, for an efficient and reliable circuit operation.

Abstract: A single phase AC input voltage is subjected to a single-phase full-bridge rectifier to obtain a first rectified voltage. The first rectified voltage has a fundamental DC component and a harmonic component, the harmonic component being defined by a ripple voltage of the first rectified voltage. The first rectified voltage is then subjected to an auxiliary rectification in which the ripple voltage of the first rectified voltage is rectified. A resultant auxiliary DC component is added to the fundamental DC component to obtain a DC component of a rectified output voltage.

Abstract: A power supply self adjusted circuit that can sense a power supply voltage and detect whether the power supply is of a first value (e.g., 5V) or a second value (e.g., 3.3 V). In the case of a modem system, the power supply self adjusted circuit then adjusts the modem system accordingly. Hence, using this circuit, a modem or other signal processing circuit can be designed to work for both 5V and 3.3V power supply systems, for example. Futhermore, the power supply self adjusted circuit enables a modem system to automatically adjust itself when the power supply is switched from 5V to 3.3V or vice versa, without any manual intervention from the user. This capability is important for increasingly-popular PC Card- modems.

Abstract: An automotive racing simulation apparatus has an electronic controller which controls a series of Christmas lights each of which is separately activatable. In addition, the electronic controller controls a sound generator activated immediately prior to the activation of the Christmas lights to more realistically simulate automotive racing conditions.

Abstract: For use in a DC/DC converter fed by a three phase rectifier, an active circuit and method for delivering an inner phase of three phase AC input power provided to the rectifier and a power converter employing the active circuit or the method. The active circuit includes: (1) a phase selection switching circuit, coupled to the rectifier, that selects an inner phase of the three phase AC input power and (2) a switching network, coupled to the phase selection switching circuit, that controls a waveshape of at least the inner phase to the DC/DC converter thereby to reduce harmonics associated with the three phase AC input power.

Abstract: A voltage step-up circuit with regulated output voltage, comprises a voltage divider and a current-absorption circuit connected between the output terminal of the circuit and ground. A control circuit connected to the divider drives the switching of the current-absorption circuit.

Abstract: Current flow between the boost inductor and the output bulk capacitor in a boost converter type power factor correction circuit for an AC-to-DC power converter is controlled by a single power MOSFET which is operated by a gate driver in a low-level constant current surge limiting mode during initial charging of the bulk capacitor, and in a high-level current-limiting mode once the bulk capacitor is sufficiently charged for normal operation. The power MOSFET gate driver is in turn controlled by a control logic which is connected to the input and output voltages of the boost converter, and which allows the circuit to cope with short circuits and input power interruptions and glitches.

Abstract: In a power supply apparatus which is used for an image forming apparatus, even when a resonance frequency extremely changes due to an influence by an inductance load just after a fluorescent lamp was lit on and after completion of the stabilization after the light-on, the apparatus can immediately follow such a change and can generate a stable voltage.

Abstract: Apparatus for irradiating a substrate is compact, transportable, rugged, high powered, and highly efficient. It includes an improved high voltage inductor (1-230), an improved power transfer apparatus (230-294), an improved voltage multiplication apparatus (500-575), an improved auxiliary power supply (600-619) for the voltage multiplication apparatus, improved accessibility self-shielding (700), and improved methods for radiation processing of solid or liquid materials.

Abstract: A differential transformer includes a magnetic core within which difference signal detection inaccuracies resulting from non-homogeneity within the core are corrected by compensation. A phase wire extends proximate the magnetic core for transporting a first current in a first direction. A neutral wire extends proximate the magnetic core center for transporting a second current in a second direction which is substantially opposite the first direction. A shunt wire is electrically connected to one of: the phase wire and the neutral wire depending on whether the transformer is undersensitive or oversensitive. The shunt wire shunts a portion of the current flowing in one of the phase and neutral wires such that first and second signals are generated in the transformer as a result of said first and second currents that are substantially equal.

Abstract: The present invention relates to electrical conversion between electrical systems, e.g. inversion. An improved power converter is disclosed, which utilizes zero current switched and zero voltage stitched switching networks either side of a link. An operating state in which one network is disconnected from the link (a zero power flow state) results in an increase in efficiency.

Abstract: An improved two-stage, high voltage inductor assembly. The inductor assembly is particularly adapted for use in a power supply circuit for an electrostatic precipitator. The inductor assembly includes a first inductor member defined by a plurality of turns of a continuous length of wire, and a second inductor member defined by a plurality of ferrite beads in end-to-end relationship. The assembly changes the electrical characteristics of power generated by a power supply to increase the output voltage, decrease ripple, and decrease the amount of power required. The assembly also reduces the arcing and sparking which normally occurs, improving the collection time and efficiency of the precipitator.

Abstract: Method for generating low magnetic fields from a three-phase conductor arrangement. Four phase conductors are used, one phase being split into two phase conductors which are arranged one on each side of the phase conductors of the unsplit phases in a planar phase arrangement. The two outer phase conductors are interconnected, thereby forming a loop. Capacitive elements can be arranged in the loop, preferably in loop-forming cross connections.

Abstract: An input protection circuit for an instrumentation system which receives an input signal and which is adapted for providing a current and/or voltage limited version of the input signal to a measurement system. The input protection circuit of the present invention utilizes an optocoupler and also includes circuitry which protects the optocoupler from damage if an over-voltage condition is detected. The input protection circuit includes a comparator which is operable to disable or turn off the optocoupler when the current limited version of the input signal exceeds a preset value. The input protection circuit preferably includes a resistor connected in parallel with the optocoupler. which provides an alternative path for the input signal when the optocoupler has been cut off. The present invention thus provides an improved input protection circuit which also protects the optocoupler from damage if an over-voltage condition is detected, but still allows the input signal to be measured during this time.

Abstract: A hybrid type image forming apparatus capable of forming a high quality image by using two image forming units having different resolution from each other, perform high throughput image forming by selecting most suitable image forming method or methods depending upon a kind of input image data, and reducing its running cost. In the apparatus, input image data of resolution of 300 dpi is separated into monochromatic image data and color image data. The monochromatic image data is converted into that of 600 dpi so that four pixels of an image of 600 dpi make one pixel of an image of 300 dpi. Then, a monochromatic image is formed on the basis of the monochromatic image data of 600 dpi by the image forming unit employing the electrophotograph method. A print medium on which the monochromatic image is formed is conveyed to the image forming unit employing the ink-jet printing method where a color image is formed on the basis of the color image data of 300 dpi.

Abstract: A staggered-frequency AC inverter includes at least first and second pulse width modulated bridge circuits connected in series. The first bridge circuit receives a DC voltage and operates at a first pulse width modulated switch frequency to generate a first output corresponding to a first region of the AC signal. The second bridge circuit receives a DC voltage and operates at a second pulse width modulated switch frequency substantially lower than the first frequency. The second bridge circuit generates a second output corresponding to a second region of the AC signal in which the AC signal changes less rapidly than in the first region, minus a maximum voltage magnitude of the first region. Another aspect of the invention features a staggered-voltage multiple-phase circuit having at least a first-phase portion for generating a voltage signal in a first phase, and a second-phase portion for generating the voltage signal in a second phase.

Abstract: The present invention relates to a print head in a powder jet image forming apparatus comprising a plurality of first electrodes formed on the surface of an insulating layer on the side of a developer supplying roller and a plurality of second electrodes formed on the surface of the insulating layer on the side of a paper conveying section, a developer through-hole being provided at each of intersections of the first electrodes and the second electrodes. In the present invention, one or a plurality of guard electrodes for drawing a developer from the developer supplying roller and supplying the developer to the first electrodes are provided around the first electrodes on the surface of the insulating layer.

Abstract: A control circuit generates signals for controlling the sequence in which selected input signals are carried across the terminals of a polyphase switching conversion circuit. The control circuit includes switching elements galvanically isolated from the selected input signals with the control signals electrically isolated from the switching devices. The control circuit for the conversion circuit is, in essence, electrically isolated from the conversion circuit. The control circuit is configured to have a topology analogous to that of the switching converter and includes conventional switching diodes as well as a light generating device optically coupled to a light sensor which, in response to detection of light from the optically coupled light generating device, provides a control signal to a corresponding switching device. The control circuit also includes a source of regulated and electrically isolated power to operate drive circuitry for the switching devices.