Showing papers on "Boost converter published in 1983"

An AC-to-DC Converter with High Quality Input Waveforms

Abstract: An ac-to-dc converter which draws sinusoidal and inphase current waveforms from the ac power source is described. Harmonic and power factor measurements obtained from a field- effect transistor (FET) converter operating at 45 kHz for a single- phase and a three-phase connection are presented. A stability analysis and design methodology are given.

Compact electrical power supply for signal processing applications

Abstract: The present invention relates to a compact electrical power supply which derives electrical energy from a low frequency medium voltage source (eg a 120 V 60 Hz ac main), and converts the electrical energy to a low voltage format suitable for solid state signal processing equipment The supply entails in succession bridge rectification means, a dc-dc boost converter, a capacitor storage bank, and a half bridge converter, either resonantly or non-resonantly operated The converters operate at frequencies substantially above audible frequencies in the interests of compactness The design provides a high input power factor (inductive) with minimum EMT, and provides a lengthened voltage hold up after loss of power

Modulated power supply for an electrostatic precipitator

Abstract: In an electrostatic precipitator system powered by a primary power source, the power supply has a converter and a high voltage device. The converter can be coupled to the primary power source for producing a converter voltage with a different frequency content. The high voltage device is driven by the converter, producing from its converted voltage a high voltage. This high voltage is influenced by the different frequency content, having at least one frequency component at a predetermined low frequency which is sized to promote efficient precipitation.

High frequency ballast circuit

Abstract: A high frequency ballast circuit powered by a dc input voltage source for starting and operating a gas discharge lamp load, comprising: a means for providing drive signals, each the drive signal having a first and second state, a series switch having a conduction channel having a first and second terminal, the series switch having a control terminal responsive to the drive signals, the conduction channel is on (conductive) in responsive to the interval characterized by the first state of the drive signal and off (non-conductive) in response to a drive signal having a second state, and an inductor. A clamp diode is included. The inductor is coupled to the clamp diode cathode and to the series switch. A ballast reactance is included with a a power oscillator circuit, the power oscillator circuit has a transformer having, a primary winding having a first, a second and a center-tap terminal, a drive winding having a first and a second and a center-tap terminal, and an output winding. A reactance tunning means coupled between the transformer primary winding first and second terminal, a first and second drive switch, the primary winding first terminal is coupled to the first drive switch, the primary winding second terminal is coupled to the second drive switch, and the primary winding center-tap is coupled to the inductor; the drive winding first and second terminal are respectively coupled to the first and second a switch control terminals. A boost circuit means, and a timer circuit operating from the boost circuit means power, and means for adjusting the duty cycle ratio of the timer circuit.

Method of digital temperature compensation and a digital data handling system utilizing the same

Abstract: A method of digital temperature compensation uses a digital temperature compensation word to produce a digital word modification of a digital input to a temperature sensitive digital to analog converter hereinafter converter. The method includes the steps of sensing the temperature affecting the converter to produce a digital temperature representation which is used by a digital computer to produce an output in accordance with a characterization equation in the form of Output=f(D, M) where D=digital data and M=f(temperature). The temperature stability of the converter is affected by the temperature stability of a reference voltage circuit used in the converter and having a voltage reference diode. A compensation circuit uses a temperature sensor in the form of a second diode, which is thermally coupled to the reference diode, and a tracking type analog-to-digital converter for converting an analog signal. The output of the analog-to-digital converter is supplied as a digital word to a digital computer system which uses the digital word to modify a digital input to the converter. The computer system includes a non-volatile memory in which is stored a characterization equation which describes the performance of the converter as a function of the digital output signal from the computer and the digital representation of temperature from the analog-to-digital converter. Thus, the output from the digital-to-analog converter is compensated for the effect of temperature on the converter.

Multi-phase DC-to-AC and DC-to-DC boost converter

Abstract: A multi-phase DC-to-AC voltage boosting converter suitable for use as the primary stage of power isolated, high output voltage DC-to-DC voltage converters. The converter is comprised of a plurality of transformer primary windings electrically interconnected in a single loop mesh configuration and a plurality of voltage boosting channels operatively associated with the respective primary windings and commonly connected to a low voltage power source. The phase channels are operated so as to periodically provide a boosted voltage potential to the primary windings in a continuously cycling, multi-phase synchronous relation to one another so that a corresponding multi-phase, high-voltage AC potential is provided across each of said primary windings. Various conventional AC-to-DC converters and voltage multiplier circuits may be inductively coupled to the transformer primary windings to provide a wide variety of highly efficient low-to-high voltage DC-to-DC boost converters.

Start-up transient control for a DC-to-DC converter powered by a current-limited source

Abstract: The start-up trajectory of the operating point of a DC-to-DC converter normally includes a high current locus which must be traversed to reach the steady-state operating point. In the case of a converter powered by a current-limited source, such as a power supply system where one converter powers a plurality of subsequent converters, the subsequent converters may be unable to turn on due to inadequate current drive. By using a control circuit adapted to control the start-up trajectory of a DC-to-DC converter as a continuous function of the input voltage applied to it by the current-limited source, the start-up characteristics are constrained to be compatible to both source and load permitting the converter to proceed to its steady-state operating point.

A water-level sensor using a capacitance to frequency converter

Abstract: A capacitive water-level sensor using PTFE-insulated wire and a capacitance to frequency converter is described. Construction is simple, yet overall linearity is 0.1%. Temperature drift of the sensor is -0.05%K-1 and that of the converter is <0.01%K-1. Long-term stability of the sensor appears excellent. The converter draws only 150 mu A from a 5 V supply and is insensitive to supply voltage variations.

Power supply unit for electronic flash

Abstract: A power supply unit for electronic flash includes a converter drive circuit which is activated when a main switch is turned on or in response to the completion of a shutter operation or the completion of a film winding operation, thereby driving a converter for oscillation. The converter charges a main discharge capacitor to a given voltage, and when the given voltage is reached, the converter drive circuit is deactivated, thereby automatically ceasing the oscillation of the converter.

Buck-boost converter with dual-mode control for battery charging

Abstract: A voltage controlled flyback converter used as a battery charging circuit avoids the power dissipation of the more conventional series-type regulator-type charging circuits but cannot be readily utilized because of the high gain in the feedback loop due to the battery voltage, which causes instabilities therein when it is operated in a continuous current mode. These instabilities are avoided in a flyback converter used for battery charging by using current control techniques to control current on the primary side of the converter during high-rate battery charging. During low-rate charging, normal voltage feedback from an output current sensing resistor is used as long as the converter operates in a discontinuous mode.

An 8b 50ns monolithic A/D converter with internal S/H

Abstract: An A/D converter, using a non-clocked successive approximation approach with an internal sample and hold amplifier, achieving an 8b conversion in 50ns, will be reported. Die size is 108×159mils and power dissipation is 300mW.

Floating battery feed circuit

Abstract: A floating battery feed circuit (10) comprising a switching-mode, flyback power converter (200) wherein a capacitor (C3) connected to a converter transformer winding (201) develops a relatively low voltage used to energize the converter control circuitry (100). The converter control circuitry prevents the operation of the battery feed circuit unless the voltage developed by the capacitor is above a predetermined magnitude. The power converter advantageously operates in only a constant-power mode regardless of loop impedance.

Flyback DC/DC converter with low ripple in the output capacitor

Abstract: A flyback type DC/DC converter includes an input filter with input capacitor (C₁), an inductance (L) in series with a power transistor (T) and an output filter with an output capa­ citor (C₂). The input capacitor (C₁) is connected in series with the output capacitor (C₂) and to the input terminals of the converter to compensate the ripple current in the output capacitor (C₂).

Output controller of fuel cell

Abstract: PURPOSE:To prevent overload applied to a fuel cell by detecting d.c. side voltage of a converter which converts D.C. power of a fuel cell to A.C. power, and suppressing increase of active power of the converter when the D.C. voltage dropped below setting voltage. CONSTITUTION:The D.C. output power of a fuel cell 5 is converted to A.C. power with a D/A converter 10, and supplied to a power line. Active power Pa and reactive power Qa are compared with setting values Ps and Qs and the converter 10 is controlled through a controller 14. Output voltage Va of the fuel cell 5 is detected with a detector 18 and compared with setting voltage Vs with a comparator 19. When output voltage dropped below setting voltage, a signal is inputted into an active power comparator 11 through a lower limit controller 21 and output to power line is controlled. Overload applied to the fuel cell 5 which is caused by quicker electricity output response than control response of fuel or air of the fuel cell is effectively prevented.

Electrical power source for resistance welding apparatus

Abstract: An electrical energy source with a static inverter and a welding transformer (12) for a resistance welding machine comprises a first static frequency converter (10) made up of semiconductor elements, the alternating output voltage of which has a frequency and pulse shape which differ from the frequency and pulse shape of the supply voltage fed to the inverter. In this connection, the pulse shape, the amplitude, and the pulse to space ratio are to be variable within wide limits. This is attained by at least one second frequency converter (11) connected in parallel to the first frequency converter (10), wherein the alternating output voltage of the second frequency converter (11) is adapted to be added in phase synchronism to the alternating output voltage of the first frequency converter (10) in the primary circuit of the welding transformer (12).

Apparatus for the current supply of a subscriber set from an exchange.

Abstract: An apparatus for applying current to a subscriber line telephone set (RL) with associated two-wire line connected to a telephone exchange. The apparatus includes two analogue amplifiers (5, 6) each with its output connected to one of the two wires of the line, and feeding out on the line the combined DC current and current representing the speech signal. A DC/DC converter supplies voltage to a at least one of the amplifiers. To form a control voltage to the DC/DC converter, a cascade connection of a differential amplifier (1), a lowpass filter (2) and an adding circuit (3) are arranged between the line connection terminals and the control signal input of the DC/DC converter.

D.C. voltage converter including a pulse width controlled semiconductor switch

Abstract: A d.c. voltage converter having alternating energy intake and energy discharge phases. The converter includes a power transformer having a core and at least primary, secondary and tertiary windings associated with the core. A primary circuit including a pulse width controlled semiconductor switch connected in series with the primary winding conducts an energy intake current during the energy intake phase of the converter. A secondary circuit including a smoothing capacitor and at least one rectifier element connecting the smoothing capacitor to the secondary winding conducts an energy discharge current during the energy discharge phase on the converter. Circuit means are provided for connecting the tertiary winding to the smoothing capacitor so that, following the energy discharge phase of the converter, excess energy of the smoothing capacitor in the form of an energy feedback current is fed back into the core until the start of the next energy intake phase of the converter.

DC Static switch with phase commutation

Abstract: An apparatus for the interruption of DC transmission lines without substantial arcing utilizing in combination a DC circuit breaker, a DC-to-AC current converter, converter control and an AC power sink. Upon command from the converter control, DC current is converted to AC current in the current converter and is then magnetically coupled via a transformer into the AC power sink; thus, drawing power out of the DC transmission line and reducing the DC current toward a zero value at which point the DC breaker can be opened without substantial arcing. Various single and multi-phase converter circuits utilizing thyristors are employed. A bypass switch in parallel with the converter can be provided to pass the DC current around the converter during normal operation of the DC transmission line to minimize electrical losses. Alternatively in multi-phase converters, normal DC current can be multiplexed among the phases of the current converter in order to distribute the heating caused by the conduction of DC current therethrough. Interruption of DC transmission lines having bidirectional DC current flow is accomplished with alternate embodiments of the invention including current converters in a back-to-back parallel arrangement, or a current converter full wave bridge rectifier combination or a current converter connected to the DC transmission line via polarity reversing switches.

Converter control apparatus and method

Abstract: The input terminals of a PWM converter are connected to the a-c power supply via a reactor. A capacitor C as well as a load 11 are connected to the d-c output terminals of the PWM converter. An apparent phase of the power supply voltage E is shifted depending upon the difference between a d-c voltage detected across both terminals of the capacitor and a set voltage, and a control signal for the PWM converter is prepared, with the shifted voltage as a reference. When the detected voltage is greater than the set voltage, the PWM converter is so controlled as to be operated with a lagging power factor, and the a-c voltage at the input terminals of the PWM converter becomes smaller than the power supply voltage. Accordingly, the d-c voltage can be maintained at a value smaller than the set voltage.

Charge control device in a flash device for a camera

Abstract: A flash device for photography includes a DC/DC converter for boosting a DC power source voltage and applying a voltage to a main capacitor for supplying an energy for driving a flashlight tube. The converter has control means operative in response to the trigger operation by a start operating switch to detect any reduction in the charging current of the main capacitor and stop said operation. The flash device is provided with another switch means for enabling the operation of the converter independently of the start operating switch. Said another switch means is operative to operate the converter until the charging voltage of the main capacitor reaches a sufficient value to drive the flashlight tube.

Static phase converter

Abstract: Single-speed, three-phase motors and two-speed, three-phase motors are started and run by a static phase converter which comprises a timing circuit, adjustable for a starting interval, and a switching device which configures a plurality of capacitors, with respect to motor windings, so that a starting capacitance and a running capacitance are connected during a starting mode for a high-torque condition, and, thereafter, the run capacitance is connected for running the motor.

An improved push-pull voltage fed converter using a tapped output-filter inductor

Abstract: A new concept of using a tapped output-filter inductor and an auxiliary commutating diode to reduce the liklihood of transformer core saturation in a push-pull, voltage-fed converter is presented. The linearized circuit model and transfer functions are derived with a hybrid approach using both state-space and circuit averaging. Operation of the new converter—including parasitic effects—is discussed, and a design equation for inductor tap ratio is established. It is predicted and experimentally confirmed that the new converter has more symmetrical transformer core operation, and the potential exists for lower transistor turnon current and reduced transistor voltage stress. These benefits reduce switching loss and enhance transistor reliability.

Equal-pulse-width modulation control strategy for an AC to DC converter

Abstract: Pulse-width modulation schemes are important for the improvement of supply power factor and AC supply waveform. A control circuit with an equal-pulse-width modula-tion scheme is developed, The circuit is used to control a simple and versatile AC-DC converter developed by Kataoka et al. (1979). The control gating pulses are selected in such a way that the converter does not require precharging of the commutation capacitor when starting the converter initially. This feature was not reported by Kataoka et al. The converter, which uses few components, can be used for both rectification and inversion. Oscillograms demonstrate the working of the converter.

Characteristics of superconducting magnetic energy storage (SMES) energized by a high-voltage SCR converter

Abstract: A small-scale Superconducting Magnetic Energy Storage(SMES) unit was constructed using small magnets and a high-voltage converter, and the characteristics of this unit were examined. The high output voltage of the converter makes it possible for even a small magnet to charge and discharge large power. Moreover, converter control provides adequate protection during quenching. AC and DC filters can be eliminated from the converter system, and ripple voltage does not harm the superconducting magnet. These features demonstrated the potential of an SMES unit as a power system stabilizer and a peak load power supply.

Effect of the Selection of Input Voltage and Maximum Operating Flux Density of Different Core Material on the Optimum Design of Switching Power Converter

Abstract: The effects of using different input voltage and different core material of different saturation flux density on the switching power converter weight minimization are presented. The design- oriented sensitivity analysis by perturbing the operating point, for example, the input voltage and the maximum flux density, reveals valuable design insights into the switching power converter global design optimization. A cost-effective computer-aided nonlinear programming (NLP) design technique is utilized for the minimum weight design. The new topology Cuk switching converter is taken as a demonstration example. Detailed loss and weight breakdowns as a function of the input voltage and the operating flux density are calculated for the optimum operation. Significant differences of the overall power converter performances are observed by using different input voltages and saturation flux densities.

Single-ended DC converter

Abstract: The invention relates to a single-ended DC converter using the forward converter principle and having a current transformer and a flyback converter inductor, whose primary windings are connected in series. The transformation ratios of the current transformer and the flyback converter inductor are selected to be of equal magnitude. The rectifier elements on the secondary side are connected to the secondary windings of the current transformer and of the flyback converter inductor, and to one another, in such a manner that a continuous load current flows.

Pulse pneumatic pressure converter

Abstract: PURPOSE: To obtain a pulse pneumatic pressure converter storing an output pneumatic pressure even at power failure with high service life by using a piezoelectric flapper for a pneumatic-electric transducer, dividing a power supply into two systems and backing up only the circuit relating to the piezoelectric element flapper. CONSTITUTION: An output voltage of a DC-DC converter 37 or a voltage of a battery 38 is inputted to a DC-DC converter 39, where the voltage is converted into around DC24V. the voltage V 2 is applied to an input electric circuit comprising an up-down counter 22, a D/A converter 23 and a comparator 24 or the like and a circuit element required minimum for holding an output pneumatic pressure such as a pneumatic-electric transducer 32 or the like. Since the voltage of the battery 38 is used as a backup power supply at power failure although no voltage is inputted to the converter 39 from the converter 37, the converter 39 generates the voltage V 2 . Thus, the piezoelectric element flapper 26 holds a potential corresponding to that at power failure and the output voltage is held to a value at power failure. COPYRIGHT: (C)1985,JPO&Japio