No description available.

No description available.

The present work describes the development of a control scheme for boost-type switch-mode rectifiers. While controllers for this circuit commonly use a shunt resistor or a magnetic field sensor to measure the instantaneous input or inductor current, here the inductor current is computed from the measured inductor voltage. This calculation requires knowledge of the physical properties of the inductor, most importantly its inductance, which are prone to change with operating conditions of the converter and throughout the lifetime of the inductor. The parameters of the inductor model are estimated during normal converter operation, and the inductor model is adapted accordingly. Simulation and experimental results confirm the effectiveness of the devised scheme in reducing the distortion of the input current. / Graduate / 0544 / aengel@uvic.ca

The present work describes the development of a control scheme for boost-type switch-mode rectifiers. While controllers for this circuit commonly use a shunt resistor or a magnetic field sensor to measure the instantaneous input or inductor current, here the inductor current is computed from the measured inductor voltage. This calculation requires knowledge of the physical properties of the inductor, most importantly its inductance, which are prone to change with operating conditions of the converter and throughout the lifetime of the inductor. The parameters of the inductor model are estimated during normal converter operation, and the inductor model is adapted accordingly. Simulation and experimental results confirm the effectiveness of the devised scheme in reducing the distortion of the input current. / Graduate / 0544 / aengel@uvic.ca

Thesis (M.S.)--University of Wisconsin--Madison, 1964. / eContent provider-neutral record in process. Description based on print version record. Bibliography: 1 l. at end.

The varactor properties of silicon—diode rectifiers in the low-frequency region are investigated. A theoretical analysis of a two-diode bridge is made, and the results experimentally verified using a matched pair of these diodes and a pump frequency of 455 Kc. The theoretical transducer power gain is found to be a function of ( formula omitted). For the amplifier built, a transducer power gain of 12.6 db has been achieved with a bandwidth from 0 to 8 Kc. With the diodes placed in a thermostatically controlled oven, the d-c drift is ±30 µvper hour. The noise figure of the parametric amplifier bridge is about 3 db. A study of possible sources of noise is made. / Applied Science, Faculty of / Electrical and Computer Engineering, Department of / Graduate

Continuous current control, so familiar in the operation of high-vacuum tubes, has not been possible, except under special circumstances, for gas tubes. Even current interruption has been awkward, except for low currents, for the usual manner of interrupting the current is to decrease the anode potential to zero. The time to switch off the gas tube has been of the order of the deionization time for the gas employed. Now a method is developed for switching off mercury-pool arcs using a third electrode. There is no interference with the main power circuit and, in fact, the potential on the anode causing the electric field aids the dispersal of the charge carriers when the arc has been interrupted. The switching-off time is much decreased because this anode-to-cathode voltage sweeps all the charge carriers out of the tube. Switching off is effected by passing a reverse current of equal or greater magnitude than the arc cathode current through the tube for a time long enough to interrupt the cathode spot. A technical difficulty arises in that the third electrode introducing the reverse current has to have an already formed or an easily formed cathode spot since this third electrode is a cold cathode. Many methods for forming the cathode spot are discussed. The method finally used is probably not the best one but it has the virtue of being easily effected. There appears to be no limit as to the current that can be interrupted if the spot-forming mechanism is altered. Energy used in not an important factor. The amount varies with the time to switch off and does not influence the actual switching process. / Applied Science, Faculty of / Electrical and Computer Engineering, Department of / Graduate

No description available.

No description available.

Thesis (SC. D.)--University of Michigan, 1935. / "Reprint from Electrical engineering ... March 1937." Includes bibliographical references (p. 8).