Voltage converter that steps up low starting voltages to higher voltages

摘要

The present invention relates to a voltage converter circuit for transforming a low voltage applied to its input into a higher output voltage at an output. The voltage converter circuit comprises at least one first to fourth controllable switch of a first type, which are connected to each other in the form of an H-bridge, which is arranged between the input voltage and a reference potential, and a transformer with at least one primary winding arranged in a transversal branch of the H-bridge, and with a secondary winding, at which a transformed voltage can be tapped for generating the output voltage. In parallel to at least one of the controllable switches at least one controllable switch of a second type is arranged, which is conductive without a control potential being applied. The secondary winding of the transformer is furthermore connected with the control inputs of the controllable switches for feeding back the transformed voltage.

主权项

1. A voltage converter comprising:
an input voltage source; an output voltage terminal at which an alternating current voltage is developed; a reference voltage source; an H-bridge circuit: (a) between the input voltage source and the reference voltage source, and (b) having:
(1) a first controllable H-bridge circuit switch branch between the input voltage source and the reference voltage source, and(2) a second controllable H-bridge circuit switch branch between the input voltage source and the reference voltage source; a transformer having: (a) a primary winding in the first controllable H-bridge circuit switch branch, and (b) a secondary winding at which the alternating current output voltage is developed and connected with the output voltage terminal; at least one of an ohmic resistance and a reactive impedance connected between the output terminal and control terminals of the first controllable H-bridge circuit switch branch and the second controllable H-bridge circuit switch branch to passively apply the alternating current output voltage to the control terminals of the first controllable H-bridge circuit switch branch and the second controllable H-bridge circuit switch branch; first n-JFET connected in parallel with the first controllable H-bridge circuit switch branch between the input voltage source and a first terminal one primary winding; and a second n-JFET connected in parallel with the second controllable H-bridge circuit switch branch between a second terminal of the primary winding of the transformer and the reference voltage source, so that when an input voltage is applied, a current flows though the n-JFETs and the primary winding towards the reference potential.