Patent ID: 6366058
Filing Date: 2002-04-02
Classification: H02M

Abstract:
A capacitor power supply unit for generating an auxiliary direct voltage supply from a main alternating voltage supply for powering an electrical consumer, the capacitor power supply unit comprising:a storage capacitor for providing an auxiliary direct voltage supply for powering an electrical consumer; a charging capacitor operable for charging the storage capacitor with current generated by a main alternating voltage supply; rectifying means disposed between the charging capacitor and the storage capacitor for rectifying the current charging the storage capacitor; switching means disposed between the charging capacitor and the storage capacitor, wherein the switching means is switchable between a first switch position for enabling the charging capacitor to charge the storage capacitor and a second switch position for disabling the charging capacitor from charging the storage capacitor; a switching time-determining member for providing a switching time control signal to the switching means, wherein the switching time control signal is a function of voltage output by the charging capacitor, wherein the switching time control signal is enabled when the voltage output by the charging capacitor is less than a reference voltage such that current through the switching means is substantially non-existent; and a charging state-determining member for providing a charging state control signal to the switching means, wherein the charging state control signal is a function of charging state of the storage capacitor, wherein the charging state control signal is enabled when the charging state of the storage capacitor is less than a limit value and is disabled wherein the switching means switches to the first switch position when the switching time control signal and the charging state control signal are enabled for enabling the charging capacitor to charge the storage capacitor.