Showing papers on "Buck–boost converter published in 1984"

High-Frequency Resonant Transistor DC-DC Converters

Abstract: Transistor dc-dc converters which employ a resonant circuit are described. A resonant circuit is driven with square waves of current or voltage, and by adjusting the frequency around the resonant point, the voltage on the resonant components can be adjusted to any practical voltage level. By rectifying the voltage across the resonant elements, a dc voltage is obtained which can be either higher or lower than the input dc voltage to the converter. Thus, the converter can operate in either the step-up or step-down mode. In addition, the switching losses in the inverter devices and rectifiers are extremely low due to the sine waves that occur from the use of a resonant circuit (as opposed to square waves in a conventional converter); also, easier EMI filtering should result. In the voltage input version, the converter is able to use the parasitic diode associated with an FET or monolithic Darlington, while in the current input version, the converter needs the inverse blocking capability which can be obtained with an IGT or GTO device. A low-power breadboard operating at 200-300 kHz has been built. Two typical application areas are switching power supplies and battery chargers. The converter circuits offer improvements over conventional circuits due to their high efficiency (low switching losses), small reactive components (high-frequency operation), and their step-up/stepdown ability.

Fuel injection apparatus employing electric power converter

Abstract: Fuel injection apparatus including a power converter for generating a stable, high voltage DC signal for powering the fuel injectors. The power converter is connected to a voltage source such as a vehicle battery. The power converter includes a DC-DC converter and a feedback-stabilized converter control circuit. The converter control circuit adjusts the operation of the DC-DC converter in a direction to counteract changes in output voltage caused by battery voltage variations. The high voltage DC signal is applied to each injector through one or more solid state switches. Since the signal used to power the fuel injectors is substantially constant regardless of normal battery voltage variations, the injector pull-in time is substantially constant. Moreover, the use of a high voltage power signal enables low current injectors to be used. The low injector current results in low power dissipation by the solid state switches which operate the injectors. The output voltage generated by the converter is also used to bootstrap the power signal applied to the converter control circuit.

Multi-step parallel analog-digital converter

Abstract: A multi-step A/D converter of the successive approximation type utilizes a single three-position switchable current-output DAC in combination with a voltage divider, a plurality of comparators, a decoder, a successive approximation register and a control logic module to provide a high speed, high resolution A/D converter requiring fewer parts than the prior art A/D converters of this general type.

Combination low-pass filter and high frequency transient suppressor

Abstract: Spikes occurring on an AC line and coupled through an AC to DC converter are substantially decoupled from a DC load of the converter even though the converter includes a supply transformer and a shunt electrolytic filter capacitor, by a circuit comprising a shunt network including a bidirectional breakdown means having a predetermined threshold conduction level with a dead band series connected with a capacitor. The capacitor is a low impedance capacitive reactance to high frequency components in pulses developed by the converter in response to the spikes, and a high impedance to ripple of the line derived by the converter. The high frequency components are supplied by the breakdown means to and through the capacitor to momentarily interrupt the flow of current from the converter to the load when the pulses are derived. A low pass filter connected in series with the shunt network and the load has a cut-off frequency lower than the ripple frequency.

Adaptive analog-to-digital converter

Abstract: The converter system includes a conventional N bit analog-to-digital (A/D) converter and also includes an automatic gain control circuit and DC offset circuit to alter the input analog signal to utilize the full N bit capacity of the A/D converter regardless of the amplitude of the input signal, within the range of the calibration of the system.

Design and operating experience of an ac-dc power converter for a superconducting magnetic energy storage unit

Abstract: The design philosophy and the operating behavior of a 5.5 kA, +-2.5 kV converter, being the electrical interface between a high voltage transmission system and a 30 MJ superconducting coil, are documented in this paper. Converter short circuit tests, load tests under various control conditions, dc breaker tests for magnet current interruption, and converter failure modes are described.

Steady-State Characteristics of the Push-Pull DC-to-DC Converter

Abstract: Six modes of operation for the push-pull 4c-to-dc converter are presented by taking into account the magnetizing current of the transformer If the inductance of the transformer is decreased, the region where the output voltage is abnormally high is expanded in the load characteristics

Capacitive d/a converter and adjusting method

Abstract: A capacitive digital to analog converter (50) which can be trimmed to obtain precise capacitor matching is provided. The trimming method may be utilized with a weighted capacitive D/A converter (50) having a scaling capacitor (52) and an ordered plurality of capacitors (51,58,60) for developing an analog output signal as a function of a digital input code. A compensation portion (59,60,61) is coupled to at least a predetermined one (58) of the capacitors for selectively changing the effective capacitive value of the predetermined capacitor (58).

Testing circuit of ad converter

Abstract: PURPOSE: To check the accuracy of an AD converter through digital signal processing by providing a digital-analog (DA) converter which outputs the input voltage of an AD converter to be tested, a counter circuit which outputs the input value of the DA converter, and the 1st and the 2nd arithmetic circuits which calculate an error CONSTITUTION: The output value of the counter circuit 1 is latched by latch circuits 4 and 5 successively every time the output value of the AD converter 8 increases by one LSB, and a subtracting circuit 6 calculates the difference between output values of the latch circuits 4 and 5 to find the quantity of variation in the output value of the counter circuit 1 corresponding to one LSB variation in the output value of the AD converter 8 The output value of the subtracting circuit 6 is compared with that of a comparator A which is set previously by a comparing circuit 7 to compare the quantity of variation in input voltage value with the one LSB variation in the output value at each input voltage point of the AD converter 8, thereby checking a differential nonlinear error COPYRIGHT: (C)1986,JPO&Japio

Digital-to-analog converter biasing control circuit

Abstract: A device for controlling the output voltage range of a digital-to-analog (D/A) converter of the type wherein the converter output voltage range is proportional to the magnitude of an applied bias current. The device comprises means to sample and store a selected converter output voltage, means to produce a variable current of magnitude proportional to the stored converter output voltage, and a source of constant current. The constant current and the variable current are summed and applied to the converter as the bias current. The converter output voltage range is dependent on the variable portion of the applied bias current which is in turn dependent on the stored, selected converter output voltage.

DC-DC converter having feedback type switching voltage converting circuit

Abstract: A DC-DC converter having a high conversion efficiency and stable output voltage. A constant current supply circuit, located between the output terminals of the converter, make it possible for the source current to decrease as a function of battery output voltage, resulting in lower current requirements for a lower required voltage boost and hence increased efficiency.

Controlled parallel converter plant

Abstract: The electrical converter or inverter plant comprises several converter modules arranged in parallel between a power supplying line and a power consuming line. Each converter module includes a power converting unit being controlled by a control circuit which monitors the current and the voltage applied from the module itself to the load line. All functions of the plant are completely distributed among the converter modules so that no central arrangement exists. To coordinate the operation of the different modules there is provided one common current (voltage) balance bus to which all the control circuits are connected. The arrangement is constructed so that the voltage on the common current (voltage) balance bus shall be proportional to the current (voltage) provided to the load line from the module which produces the largest load current (voltage). This is obtained in a simple manner by connecting each control circuit with the common balance bus via an idealized diode.

Thyristor converter control apparatus

Abstract: An apparatus for controlling a thyristor converter in- dudes a plurality of voltage detectors (3, 4, 5) provided for individual series-connected thyristors (1) respectively for detecting the presence or absence of voltage applied to the thyristors, and elements (6-1, 10-1, 7, 8) for generating a thyristor triggering pulse signal representative of the logical sum of the voltage presence-absence signals from the voltage detectors and a triggering command signal commanding the desired triggering phase and on-period of the thyristor converter. The apparatus comprises a plurality of differentiation circuits (6-1, 6-2) differentiating the output signals of the plural voltage detectors respectively, and a signal synthesis circuit (14) synthesizing the output signals of the differentiation circuits to generate an output signal indicative of the voltage presence or absence. By virtue of the above construction, the thyristor converter can con- tinuosly operate without being shut down even when any one of the thyristor voltage detection signals is disabled.

Method and device for stopping a DC intermediate-circuit converter

Abstract: If it is desired to stop the converter in a converter having a current [sic] intermediate circuit, by reducing the frequency to zero, then the commutating capacitors must be adequately charged in the correct polarity for starting operation again. To this end, if the frequency falls below a predetermined frequency limit, on the one hand the intermediate circuit current is limited to a constantly predetermined value, and on the other hand the invertor is operated at an increased commutating frequency until a predetermined phase angle in the commutation cycle is reached. When this predetermined phase angle is reached, the commutation cycle is stopped and the converter is blocked. There is then so much energy stored in the invertor that the commutation cycle can be started again at any time at this predetermined phase angle.

A new firing scheme for converter control

Abstract: A new firing scheme for converter control is proposed. This circuit may be used for controlling both line and forced commutated converter configurations. The advantages being simplicity and ease of control. The delay angle is proportional to the control voltage and variation can be obtained throughout 180°. The circuit may comfortably be used for closed-loop operation

Ac-harmonics of power converter loads and the distortion of power system voltages

Abstract: Calculation of dynamic effects of power converter loads in the frequency domain is suggested. In this case the converter loads must be simulated by their frequency spectrum which is dependent on the actual operation mode of the converter load and on the feeding ac-voltage frequency spectrum. The dynamic effects on the feeding network can be reduced not only by means of compensation equipment but also by an optimal on-line-control of the power converter loads' operation. An optimizing method based on the maximum principle of Pontrjagin is described.