Patent ID: 6040640
Filing Date: 2000-03-21
Classification: H02J

Abstract:
A device for backing-up a DC voltage at a DC voltage output of a power-line operated power supply, the power supply supplying power to a load, the device comprisingat least one back-up battery; anda control unit performing the following functions:comparing an actual value of the DC voltage at the DC voltage output to a predetermined minimum value,connecting the at least one back-up battery to the DC voltage output of the power supply when an actual value of the DC voltage is less than the predetermined minimum value, the at least one connected back-up battery providing a battery voltage which, together with the DC voltage at the DC voltage output of the power supply, supplies the power to the load,determining a predetermined back-up time period,disconnecting the at least one connected back-up battery from the DC voltage output of the power supply after the predetermined back-up time period expires, andrepeating a comparison of the actual value of the DC voltage to the predetermined minimum value.