초록 ▼

Known converters for converting a d.c. voltage at their input to a rectifiable a.c. voltage at the output operate reliably with very small input voltage fluctuations and relatively small fluctuations in load. In order to increase the range of input voltages and loads, it is proposed that a full-brid

Known converters for converting a d.c. voltage at their input to a rectifiable a.c. voltage at the output operate reliably with very small input voltage fluctuations and relatively small fluctuations in load. In order to increase the range of input voltages and loads, it is proposed that a full-bridge converter with filter capacitors in one bridge branch be operated under low-load conditions as a half bridge, such that the capacitors form the midpoint of the half bridge, and under high-load conditions to change to full-bridge operation.

대표청구항 ▼

[ What is claimed is:] [1.] A converter for converting a d.c. voltage at the input into a rectified a.c. voltage at the output, with a resonant full-bridge chopper circuit, comprisinga first half bridge circuit means with first and second controllable electronic switches;a second half bridge circuit

[ What is claimed is:] [1.] A converter for converting a d.c. voltage at the input into a rectified a.c. voltage at the output, with a resonant full-bridge chopper circuit, comprisinga first half bridge circuit means with first and second controllable electronic switches;a second half bridge circuit means with third and fourth controllable electronic switches which are each bridged by first and second capacitor means respectively;an output transformer, the primary winding of which is arranged in series with a third capacitor means and the primary winding and third capacitor means being connected to each of the first and second half bridge circuit means at midpoints between the respective first and second, and third and fourth electronic switches;a first inductor connected in parallel with the primary winding of the transformer; andcontrol circuit means connected to said electronic switches and operative(a) in a "low load" operating state to form a half-bridge push-pull converter in a situation with at least one of a low output voltage, a high input voltage and a small load, the first and second electronic switches being opened and closed in alternation and their pulse width being modulated while the third and fourth electronic switches remain closed, and(b) in a "high load" operating state to form a full-bridge push-pull converter in a situation with at least one of a high output voltage, a low input voltage and a large load, the aforesaid electronic switches of both first and second half bridge circuit means being opened and closed in alternation and drive pulses for the aforesaid electronic switches being shifted in phase between the two half bridge circuit means for the purpose of regulation.