Converter with continuous currents flowing through secondary windings

A fast voltage ramp generator comprising a chain of transistors in avalanche switching mode connected collector to emitter in series, each said transistor being connected to have a low resistance path between its base and emitter, a voltage source connected across said chain between the collector of a transistor at one end of the chain and the emitter of a transistor at the other end of the chain and arranged to bias said transistors to avalanche switching mode, and a discrete transformer having a respective secondary connected to apply a switching pulse across the base-emitter junction of each of the transistors of the chain to initiate avalanche switching of the transistors of the chain to generate a fast ramp voltage across the load, said transformers having respective primaries which are connected in series, wherein said voltage source connected across said chain is a balanced source and there are an even number of transistors in said chain and associated discrete transformers, said generator including a switching pulse driver connected to apply a balanced switching pulse voltage across said series connected transformer primaries, wherein the transformers having primaries directly connected to said driver, at opposite ends of said series connected primaries, are associated with two central transistors at or adjacent to the centre of said chain, the transformers having primaries connected next to said end primaries are associated with the next transistors outwards from said central transistors, and so on, so that two transformers having primaries at or adjacent to the centre of said series connected primaries are associated with the end transistors of said chain.

A fast voltage ramp generator comprising a chain of transistors in avalanche switching mode connected collector to emitter in series, each said transistor being connected to have a low resistance path between its base and emitter, a voltage source connected across said chain between the collector of a transistor at one end of the chain and the emitter of a transistor at the other end of the chain and arranged to bias said transistors to avalanche switching mode, and a discrete transformer having a respective secondary connected to apply a switching pulse across the base-emitter junction of each of the transistors of the chain to initiate avalanche switching of the transistors of the chain to generate a fast ramp voltage across the load, said transformers having respective primaries which are connected in series, said generator including a switching pulse driver connected to apply a switching pulse voltage across said series connected transformer primaries, wherein said driver comprises a driver avalanche transistor having its collector-emitter circuit capacitively coupled across said series connected transformer primaries, a triggering transformer having a secondary connected to provide a low resistance path between the base and emitter of said driver transformer, a drive voltage source connected across the collector and emitter of said driver transistor and having a value exceeding the collector-base breakdown voltage of said driver transistor, a resistance in series with said drive voltage source to limit the collector-base breakdown current through the driver transistor to a quiescent value below the current at which avalanche switching of the driver transistor occurs, and a triggering pulse source, the triggering transformer having a primary connected to receive a triggering pulse from said source to trigger the driver transistor into avalanche switching.