Abstract: A converter for powering a discharge lamp of a motor vehicle headlight, the converter comprising a primary circuit and a secondary circuit which includes two branches connected in parallel, each of which is coupled by mutual induction with the primary circuit, and two diodes connected in such a manner as to prevent either of the branches discharging into the other, the transformation ratio by mutual induction with the primary circuit of one of the two branches being greater than the transformation ratio of the other, the branch having the greater transformation ratio including a switch controlled by control electronics in such a manner as to be on whenever the voltage of the lamp is greater than a given threshold voltage, and to be off whenever said voltage becomes less than said threshold.

Abstract: A power supply for converting a plurality of alternating current (AC) and direct current (DC) input line voltages to a DC output voltage includes a converter for converting the input voltages to an intermediate voltage at a first node; a switching regulator having a power voltage at a second node for providing a reference voltage therefrom, and for providing a switching signal at a third node from the reference voltage and a feedback voltage; a circuit for electrically interconnecting the first node to the second node whenever the intermediate voltage exceeds a predetermined voltage; a transformer including a primary winding electrically interconnected with the first node, and a secondary winding having a secondary voltage; a feedback circuit cooperating with the transformer for providing the feedback voltage therefrom; a switching circuit responsive to the switching signal at the third node for switching an electrical current from the first node through the primary winding; and a circuit electrically interco

Abstract: A frequency adjustable, zero temperature coefficient referencing ring oscillator circuit includes a plurality of inverter stages each having a switching circuit that produces the oscillating output signal for the ring oscillator circuit and a control circuit that controls the switching circuit to establish the frequency of the output signal, the control circuit including field-effect transistors which are operated as output resistance controllable devices and which have their operating points, and thus their output resistances, established by a reference voltage that is produced by a precision reference voltage generating circuit so that the operating frequency of the ring oscillator circuit can be set by adjusting the value of the reference signals produced by the precision reference signal generating circuit and is maintained at the setpoint value because the precision reference voltage generating circuit operates independently of variations in temperature and/or the power supply voltage.

Abstract: A power magnetic device, a method of manufacture therefor and a power converter. The power magnetic device includes: (1) an isolation transformer having a primary winding and a secondary winding, (2) a switch coupled to the primary winding, (3) a rectifier coupled to the secondary winding and (4) an encapsulant substantially surrounding the isolation transformer, the switch and the rectifier to join the isolation transformer, the switch and the rectifier into an integrated package, the integrated package having: (a) a first power input coupled to a first end of the primary winding, (b) a second power input coupled to the switch, (c) first and second power outputs coupled to the rectifier circuit and (d) a control input coupled to the switch, the control input allowing the switch to be controlled to couple the primary winding to a source of electrical power, the power magnetic device thereby capable of employing the isolation transformer and the rectifier to convert electrical power into DC electrical power.

Abstract: The improvement proposed relates to the dipole ring magnet in a magnetic field generator for magnetron plasma in an apparatus for plasma sputtering or plasma etching. Different from the conventional dipole ring magnet, which is an assembly of anisotropic columnar segment magnets in a circular arrangement each in an integral columnar form, each of the segment magnets according to the first aspect of the invention is divided into upper and lower halves and the gap space held between the upper and lower halves is varied from position to position so that the uniformity of the magnetic field formed inside of the dipole ring magnet is increased in the horizontal direction with consequently increased uniformity of the plasma density generated thereby.

Abstract: A system and method for providing harmonic currents to a harmonic generating load connected to a multiphase alternating current power system includes a zig-zag transformer and a current generator. The zig-zag transformer is electrically connected to the multiphase alternating current power system. The current generator is electrically connected between a neutral of the zig-zag transformer and a neutral return path of the multiphase alternating current power system. The current generator injects a harmonic current into the neutral of the zig-zag transformer which in turn, reduces the harmonic currents provided to the load from the multiphase alternating current power system.

Abstract: Apparatus for controlling a load connected to an internal combustion engine during operation is disclosed and claimed. The apparatus comprises a suction switch (12) which is sensitive to a decrease in vacuum in the manifold (16) of the vehicle when more motive power is required. The switch (16) causes a controller (30), at terminal (44) thereof, to provide a voltage higher than a predetermined set voltage at the D+ terminal of a conventional regulator (46), thereby to interrupt current flow in the excitation circuit of a conventional alternator (48). The alternator is consequently switched off to reduce the load connected to the engine, thereby to make more engine power available to the drive wheels of the vehicle. The apparatus thus also serves as a fuel saving device.

Abstract: An electrical power inverter with a controllable output voltage waveform is disclosed. In a preferred embodiment, the electrical power inverter has a trapezoidal output voltage waveform with rising and falling edges that are controlled such that their slopes are kept below a selected value.

Abstract: A triac-based electronic control system (20) for an electrical appliance which alternately applies and disrupts power in full cycles or full half cycles. Each zero crossing in a wave cycle is detected and this information is input into a microprocessor (U1) along with a user selected power level. The microprocessor outputs a triac control signal (36) to alternately turn ON and turn OFF power to a heater element (22) to produce a duty cycle used to achieve the desired heating level.

Abstract: According to the timer device of the invention, a time-setting part supplied from the power supply sets up the period from the opening instance of said switch to the instance that the magnitude of current in the capacitor comes down under a specified value, as said current-supply period, and a current-controlling part allows the current to flow from said power supply to said load during said current-supply period determined by said time-setting part, and a switch makes the time-setting part operate at opening instance of the switch.Therefore, the timer device of the invention can reduce the loss of power during the waiting period. And when the magnitude of the current flowing through the time-setting part and the current-controlling part in open-state of the switch, in order that the decrement of the current in the current-controlling part makes the current in the time-setting part rapidly decrease, these parts are interconnected with each other.

Abstract: A set of command signals is generated for application to the respective lines of a four-wire three phase power distribution system to compensate for harmonic distortion and neutral unbalance. A transform operation is performed upon a first set of signals, which collectively represent the uncompensated load current in each of the main transmission lines of the power distribution system, to generate a second set of signals which collectively represent the active and reactive components of the current in the system. Signal components at the fundamental frequency of the three phase system are removed from the active and reactive components to provide only harmonic active and reactive components. A reverse transform operation is performed upon the harmonic components to provide a set of command signals.

Abstract: The present invention relates to an improving circuit of uninterruptible power system which especially improve the flyback circuit and charging circuit.

Abstract: A pulse-width modulated (PWM) circuit applies voltage to a load with high fidelity. The circuit includes switches connected in series with inductors, the inductors being magnetically coupled to other inductors connected to the gates of the switches. The arrangement of inductors and the magnetic coupling causes the turn-on of one switch to assist in the turn-off of the other switch. A pair of diodes connected across some of the inductors assures that the magnetically coupled inductors do not assist the switches to turn on. The result is a circuit which effectively eliminates the problem of "shoot through" current, without providing a "dead time" in the switching scheme, and thus without substantial power losses. The circuit can therefore be used in audio amplification, and in other applications requiring high fidelity.

Abstract: A power system compensator apparatus comprising a power converter unit that works in series with the transmission of a power system and switching control means for controlling the link voltage (V.sub.LINK) of the non-power system side. The switching control means controls the phase of, at least, the fundamental frequency of the power system. The power converter unit contains a static power converter transformer with phase differences taking place the secondary windings of the power converter unit. The static power converter unit is operated in non-PWM or fixed pulse width ratio. Switching rate is minimized. Loss is lowered while economy of operation is improved. Since the voltage that works in series with the power transmission line is controlled, direct compensation of system reactance voltage and direct control of line current are performed. Improved performance thus results.

Abstract: A light is dimmed by pulsing it at a selected duty cycle. By pulsing, the light can be dimmed without being turned off completely which reduces wear on the filament. The circuit is designed for flashing a pair of ditch lights on a railroad locomotive. The lights are alternately illuminated at full voltage and dimmed by pulsing. The flashing sequence can be activated when the locomotive is travelling below a selected speed or when the horn is sounded. The duration of the flashing sequence is controlled by a timer. The pulsing circuit can be used to effectively reduce a voltage without voltage dropping resistors.

Abstract: An improved bridge rectifier for an alternating current generator includes a first heat sink, an insulating layer disposed on the first heat sink, and a second heat sink disposed on the insulating layer.

Abstract: A current source circuit is contained in an output control IC and amplifies a feedback current produced by a photocoupler by 7 to 10 times. The current amplifier has an adequate current amplification factor and is composed of an IC. A capacitor connected to the oscillator is charged by a current amplified at the current amplifier and a period of the output of the oscillator is controlled by the charging current. A conductive period of the switching device connected to the oscillator through a driver is also controlled. Accordingly, the amount of energy supplied to the secondary side of the switching transformer is also controlled and a stable secondary dc output voltage is produced. A stable voltage control is obtained over a wide range of loads, from a light load to a heavy load.

Abstract: A controller for supplying a switching signal to a switched mode power supply, includes a sinusoidal-like wave generator, and circuitry for selectively shifting a dc level in the sinusoidal-like wave whereby a duty cycle of the sinusoidal-like wave at a predetermined threshold level, corresponding to a turn-on level of a power switch in the switched mode power supply, is effectively controlled.

Abstract: A fixed and a user adjustable voltage reference is alternatively provided by an integrated switch which switches between two current sources according to an input voltage. A fixed reference voltage is achieved by amplifying the current of one of the two current sources according to a predetermined voltage difference between the output terminal and an internal reference voltage. An adjustable reference voltage is achieved by amplifying the current of other of the two current sources according to a voltage difference between the internal reference voltage and an user adjustable voltage. In one embodiment, the user adjustable voltage is achieved by a user adjustable voltage divider circuit.

Abstract: A charging apparatus charges a secondary battery in alternating charging and rest periods. The charge amount supplied in the charging periods is restricted to an amount which reduces or eliminates deterioration of the secondary battery by overcharging.