Showing papers on "Boost converter published in 1981"

DC-to-DC Voltage converter

Abstract: A DC-to-DC voltage converter is disclosed for converting the voltage from a battery to provide a power supply voltage whose value can be equal to the battery voltage multiplied by or divided by a non-integral factor, e.g. 2/3. The converter operates on the principle of capacitor charge switching, and high conversion efficiency is achieved in operation at very low levels of supply current, such as are utilized in an electronic timepiece.

Bi-lateral four quadrant power converter

Abstract: A power converter which supplies AC or positive or negative DC output voltage with positive or negative current while isolating the output voltage from the input power source This converter includes a pulse width modulator converts power amplitude signals to pulses of proportionate width A power driver circuit applies these pulses to a sychronous demodulator and low pass filter via a pulse transformer A low output impedance is presented to all output disturbances such that the converter can source or sink current in true four quadrant operation, including the passing of power from output to input when a load voltage exceeds the intended supply voltage

Method of equalizing the voltages of the individual cells of storage batteries

Abstract: There is disclosed a method of equalizing the voltages of the individual cells of a storage battery that consists in the steps of, 1. providing a single input circuit type of d.c. to d.c. converter incorporating multiple output circuits equal in number to the number of cells of the battery to which it is planned that the converter will make connection, with the converter so designed and employed that, with its input circuit connected to the terminals of the battery, and one of each of its output circuits connected across one of each of the cells of the battery, flow of cell equalizing current will hold low so long as the downward departures of the voltages of the battery's cells from average cell voltage hold below a prescribed index value. 2. providing, via method of converter design and employment, and choice of the above referred to index value, so that, for a given type, size, and prior condition of use of a battery, employment of the converter as in step 1 above can be expected to provide a cost-effective way to both favorably affect the equality of the battery's cell voltages, and avoid cell voltage reversal during battery discharge under contemplated conditions of the battery's use. 3. providing to connect one of each of the output circuits of the converter across one of each of the individual cells of the battery. 4. providing so that when the battery is in active use the input circuit of the converter will be energized from the battery's terminals. 5. providing a means of indicating when the extent of inequality of the cell voltages of the battery is such as to cause converter input current to exceed a preset value.

Dual mode dc/dc converter.

Abstract: A DC/DC converter operates at peak efficiency in either of two output current level states in response to the power demands of an associated electronic device, thereby reducing wasted current to a minimum. The converter is designed to operate from a one-cell battery, and is particularly suited to an integrated circuit implementation.

Current control apparatus for a flyback capacitor charger

Abstract: A DC to DC flyback converter for charging a capacitor in which the maximum current supplied from a battery to the converter's transformer is determined solely by the battery recovery voltage, circuit resistances, the transformer turns ratio and semiconductor junction voltages.

Free-running blocking oscillator-type converter

Abstract: A free-running blocking oscillator-type converter for producing a controlled output signal. The converter is provided with a primary winding of a transformer, a switching transistor, and a resistor which are connected in series with one another between first and second input terminals of the converter. The transformer is further provided with a feedback winding which is coupled to the base terminal of the switching transistor. In some embodiments, optoelectronic coupling devices are used in a sensor arrangement for providing a control signal responsive to variations in the magnitude of the output signal of the converter. In other embodiments, such variations in the output signal of the converter are sensed by a transformer winding. Circuitry is disclosed for applying the sensor control signal selectably to the base and emitter terminals of the switching transistor.

Voltage balance control for split capacitors in half bridge DC to DC converter

Abstract: An AC to DC converter that utilizes a split capacitor, half bridge, DC to DC converter compensates for unequal voltages across each member of a split capacitor bank. A voltage balance control circuit senses any differences in voltages across the member capacitors and generates an error correcting signal for modifying steering signals to an inverter that is used to convert a DC signal from the half bridge DC to DC converter to a high frequency pulse width modulated AC signal by alternately placing each member of the split capacitor bank and consequently their stored energy across the output terminals of the inverter. The error signal causes the steering signals to connect the member capacitor with the larger sensed voltage across the output terminals for a relatively larger period of time than the capacitor with the lesser sensed voltage.

Electronic watthour meter

Abstract: An electronic watthour meter including a pulse width modulation circuit for converting a voltage signal proportional to the load voltage across the power supply lines to a pulse width duty cycle signal and a current-to-voltage converter for converting a current signal proportional to the load current across the power supply lines to a voltage signal. A multiplication circuit issues the product of the voltage signals under the control of the pulse width duty cycle signal as a pulse signal proportional to the instantaneous power consumption of the power supply lines. A filter circuit integrates the pulse signal of the multiplication circuit as an integrated voltage signal. A voltage-to-frequency converter converts the integrated voltage signal to a pulse signal proportional to the consumption power of the power supply lines. An automatic compensation circuit integrates the pulse signal of the voltage-to-frequency converter as a feedback signal to the input of the voltage-to-frequency converter thereby eliminating the inherent offset voltage caused by the pulse width modulation circuit, the current-to-voltage converter and the voltage-to-frequency converter.

Statistically adaptive analog to digital converter

Abstract: An improvement in an analog-to-digital converter wherein a series string of capacitors is utilized to generate reference voltages for the comparators of the converter. The digitized output of the converter is then used to control a predetermined timed discharge from a selected one of the series string of capacitors. The converter, as described, may be used in a video system as an adaptive contrast enhancement mechanism.

Two-stage a-to-d converter

Abstract: A two-stage analog-to-digital converter wherein the first stage is a resistor-string d-to-a converter controlled by a successive-approximation register, functioning in a first phase of the conversion operation to determine a set of higher order bits of the digital output signal The second stage is a dual-slope integrating-type a-to-d converter functioning in a second phase of the conversion operation to determine the remaining lower-order bits of the digital output signal The dual-slope converter receives a reference signal derived from two adjacent junction points of the first-stage resistor-string d-to-a converter corresponding to the higher order bits determined in the first phase of operation, thereby to assure high resolution performance

Integrated circuit comprising a plurality of voltage-current converters

Abstract: An integrated circuit comprising a plurality of adjustable voltage-current converters, of which one converter is employed as a reference converter. The reference converter is included in a control loop. To the input of the reference converter an input voltage is applied in that a first current is passed through a reference resistor connected to said input. A second current, which is in a fixed ratio to said first current, is compared with the output current of the reference converter and this reference converter is then biassed so that its output current corresponds to said second current. In this way the transconductance of the reference converter is determined by the reference resistor and the ratio of the first and the second current, so that this transconductance is highly independent of process, temperature and supply-voltage variations. The other converters are biassed by signals derived from the bias signals for the reference converter and thus have corresponding transconductances.

Digital-to-analog converter and analog-to-digital converter with controllable bi-polar and uni-polar capability

Abstract: The digital-to-analog converter comprises an R-2R ladder network with bit controlled current steering switches connecting the legs of the ladder network to first and second current buses. First and second current-to-voltage converters are connected to the current buses respectively, the second current-to-voltage converter being connected through a switch to the input of the first current-to-voltage converter. A uni-polar/bi-polar control signal renders the switch conductive or non-conductive in accordance with the data format desired. The digital-to-analog converter is also utilized in a successive approximation analog-to-digital converter.

Analog-to-digital converter circuit

Abstract: PURPOSE:To reduce the error in conversion, by forming a reference voltage at A/D conversion of lower-order bits based on upper-order bits of a digital output and providing an offset corresponding to the upper-order bits for the reference voltage. CONSTITUTION:A 3-bit parallel A/D converter 11 converts an analog input voltage Vin into digital outputs, upper-order three bits H2-H0 and lower-order three bits L2-L0 in time division. The signals H2-H0 are applied to a latch 15 in three bits and switches 12, 13 are changed over into inverted state as shown in figure. The signals H2-H0 from the latch 15 are applied to a D/A converter 16, where the signals are converted into an analog voltage V16 having a value three times the signals H2-H0 and the analog voltage is applied to the converter 11 through the switch 13 as a reference voltage for lower limit. The voltage V16 is offset by 8V at a DC power supply 17 and applied through the switch circuit 12 as a reference voltage for upper limit for the converter 11. Thus, errors at a joint between the upper-order and the lower-order bits can be eliminated.

Method for mains feedback of a line commutated direct converter and control circuit therefor

Abstract: 1. A method for reducing main feedback from a line-commutated direct converter (I, II) when connected to a three-phase mains supply (R, S, T), by modulating a controllable reactive power compensator (5, 6, 7) connected to the three-phase mains, characterised in that the theoretical value (i*B ) for the control (8) of the reactive current to be supplied by the reactive power compensator is formed independently of the actual value of the reactive current, from the product ( iA . cos psi = iq1 ) of the amount of the direct converter output current (iA ) and a predetermined function (cos psi) of the direct converter control angle (psi) derived from the control voltage (UST ) of the direct converter (I, II) or from the direct converter output voltage (Ua ) (Figure 1).

Flash device of 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.

Cross-tied current regulator for load commutated inverter drives

Abstract: A control system for an AC motor drive including a source side converter and a load side converter coupled together by means of a DC link circuit wherein the current in the DC link circuit is controlled by either the source side converter or load side converter depending upon which converter is capable of control. This is achieved by crosstieing a signal from the normal regulating path in the source side converter control to the alternate regulating path in the load side converter control. This signal is chosen to be indicative of the source side converter controller being unable to control current, and may be derived from current error. This signal operates to alter the firing angle of the load side thyristor bridge to regulate the DC link current in the event the source side converter is unable to maintain the required current regulation.

Spannungsmesseinrichtung zur ventilsteuerung von stromrichtern in hgue-anlagen

Abstract: In the case of a device for producing the correct-phase image of the high AC voltage (U1) of a network for controlling the line-commutated valves of a converter, which is connected to the network via a converter transformer (1, 2, 3, 4), in a high-voltage DC transmission system, an auxiliary winding (6) is provided in the converter transformer.

Electric discharge lamp adapter circuits.

Abstract: not available for EP0030785Abstract of corresponding document: US4342948A converter circuit for addition to the existing lamp operating circuitry of a high pressure mercury lamp consisting of an existing series ballast inductor and a power factor connecting capacitor connected across the input terminals of the existing lamp operating circuit includes inductance arranged to be connected to the ballast inductor so as to adjust the resultant series inductance to a value suitable for a sodium lamp, and an igniter portion coupled to the converter inductance. The igniter portion operates to apply ignition voltage to the sodium lamp during at least part of the time that the converter circuit is supplied with power. Protective circuitry is coupled to the converter inductance to block or limit high frequency voltage pulses which could otherwise reach the ballast inductor.

Start-Up Transient of a DC-to-DC Converter Powered by a Current-Limited Source

Abstract: An analysis technique is presented which permits the designer to explore the start-up transient of a dc-to-dc converter when it is powered by a current-limited source. The current versus voltage characteristics of the source are superimposed upon those of the dc-to-dc converter. By noting the nature of the intersection of these curves in the voltage-current plane, we are able to predict whether or not the converter is able to start up while powering a specified load.

Spindle drive generating system

Abstract: PURPOSE:To prevent the mutual interference of frequencies between the input and the output by providing a beat phenomenon detector when an AC generator is driven by a variable speed drive source and a load is connected through a stationary converter, thereby correcting a frequency command. CONSTITUTION:An AC generator 1 is driven by an engine or the like, and electric power is supplied through a stationary converter 2 which has a power reactor 3 and a power inverter 6 to a load 7. At this time, a beat phenomenon detector 10 is provided at the output side of the converter 2, a frequency command to a frequency converter 9 is corrected by the output, thereby slightly displacing the frequency command. Accordingly, frequency difference can be always produced between the input and the output of the converter 2, thereby reducing the size of the system without increasing the reactor 4 and the condenser 5 in the converter 2 and preventing the beat phenomenon which occurs when the frequencies of the input and output approach to each other.

A Resonant Converter with PWM Control

Abstract: A dc-to-dc converter of resonant type regulated by PWM means is presented. The converter consists of two stages. The first stage is the boost converter with a switch of MOS FET. The change of the output voltage is regulated by this switch. The second stage is the self-oscillating inverter with rectified output. In the dc side of the output rectifier, a parallel capacitor is connected. A resonant condition is satisfied between the capacitor and the leakage inductance of the inverter transformer. The resonant frequency is almost the same as that of the oscillating frequency. With the resonance phenomena, the switching loss of the transistor is decreased. A good regulation is obtained by the feedback from the output to the boost converter.

A novel pulse delay circuit for converter control

Abstract: A new pulse delay circuit for converter control is described. The circuit is versatile in the sense that- it can be used for many converter configurations employing line and forced commutations.

Converter for converting an a.c. voltage into a direct current and an oscillator circuit using said converter

Abstract: A converter (300) for converting an a.c. voltage (SP) into a direct current (i 3 ), characterized in that it comprises a first elementary converter (21) which, in response to the a.c. voltage (SP), provides a pulsed direct current (i 1 ), the mean value (i 1 ) of which is a steeply rising function of the amplitude A of the a.c. voltage (SP), and a second elementary converter (22) which, in response to the current i 1 provides a current i 3 , the value of which is a steeply falling function of i 1 . Used for regulating the amplitude of the oscillation signal of an oscillator.

AC-AC Converter device

Abstract: The present invention is an AC--AC converter device comprising a converter circuit capable of producing an instantaneously varying output voltage, and a coupled reactor commutating inverter circuit cascade-connected thereto, the inverter circuit having a plurality of thyristors which are rendered conductive in a predetermined sequence, in which the output voltage of the converter circuit is rendered positive, negative or zero as necessary to effect commutation and current control in the inverter circuit.

A 12b A/D converter

Abstract: This report will discuss a 12b AD converter with integral track and hold fabricated in compound monolithic form. Chip displays less than ± 1 LSB total error over a -55 to 125°C temperature range.

Power-Factor Improvement of Single-Phase Converter by Means of Bias Voltage Control

Abstract: Power-factor improvement and harmonic reduction in ac line current, as well as stable and reliable operation, are very significant areas in the high-power ac-dc converter. The improvements of these characteristics of the single-phase converter may be generally difficult compared with the polyphase type. A new converter scheme suitable for the high power single-phase converter to overcome the above problems is presented. The basic configuration and principle of operation of the new converter scheme, theoretical characteristics and design indexes, and the drive system and characteristics of a dc series motor by this scheme are described. The basic principle of operation is verified and the feasibility of this converter system is demonstrated by experiments.

Power supply for solar cell output - has adaptive DC=DC converter to raise or directly connect cell output to storage accumulators

Abstract: Power supply unit for electrical equipment, primarily agricultural electric fences, using solar cells, dc/dc converter and storage batteries. The dc/dc converter circuit also regulates the output from the solar cells for optimum performance, i.e. supply to equipment and charging batteries under sunny and cloudy conditions but allowing discharge to power the equipment at night and during rainy weather. The dc/dc converter (11) raises the lower voltage output (U1) from the solar cells (4), under adverse light conditions, to the value required (U2) for charging the storage accumulators (5). The converter also charges the accumulators directly via the primary (1) of the converter transformer and a diode (8) when the solar cell (4) output exceeds the accumulator (5) potential under favourable conditions. Operation is controlled by an output switching transistor (2) associated with the output diode (8) and by the converter internal circuitry (13).