| 摘要 |
A d.c.-to-d.c. converter is equipped with a switching regulator in which the energy storage, instead of being a storage choke, is a series-resonant circuit, the input side of which is switched alternately between two different voltages, one of whi ch may be ground potential. The switching is performed by an electronically controlled switch. A current converter is interposed in series between a series-resonant circuit an d a full-wave rectifier which charges a capacitor connected across the load circuit. The current converter has an output providing an alternating voltage in phase with the curre nt in the series circuit. After simple processing this alternating voltage is fed back to control the electronic switch, but it is first passed through a correlation circuit in which a regulating voltage at times causes the feedback to be interrupted. The regulating voltage i s typically a binary error signal derived by comparison of the output voltage with a reference voltage. The advantage of this regulator is that the switching times o f the electronic switch may coincide with the null transitions of the current of the series-resonant circuit, thus providing high efficiency. The converter contains an inverted rectifier power supply which is also usable for other purposes, e.g. as a high f requency generator for a high frequency surgical apparatus. This power supply comprises t he series resonant circuit, phase detector means and feedback means for applying sw itching pulse flanks to the electronic switch. Excitation of oscillation in the inverted rectifier is produced which occurs as accurately as possible at the frequency of resonance of the series resonant circuit. A regulating voltage only blocks or passes the output v oltage of a pulse shaping means contained in the phase detector means to input stages of t he electronic switch at such times, at which the current in the series resonant cir cuit is zero or at least as far as possible close to zero.
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