Patent ID: 6212411
Filing Date: 2001-04-03
Classification: H04M

Abstract:
A power supply circuit comprising:a line voltage forming circuit for forming a first voltage that is proportional to a line voltage provided by a telecommunication line;a supply voltage forming circuit for forming a second voltage from said first voltage, said second voltage being proportional to said first voltage;a sensing circuit for sensing said telecommunication line and for providing a sensor signal that is representative of power provided by said telecommunication line, said line voltage forming circuit being controlled by said sensor signal such that a slope of a load line characteristic of said line voltage forming circuit is modified when said sensor signal is above a predetermined threshold signal, said load line characteristic defining an increase of said line voltage with an increase of a line current provided by said telecommunication line;wherein said sensing circuit comprises a current sensor, and a current comparator coupled to said current sensor, said predetermined threshold signal being a current threshold signal that is provided to said current comparator, and said current comparator providing said sensor signal; andwherein a further current threshold signal is provided to said current comparator, said further current threshold signal controlling further modification of said slope when said sensor signal is above said further current threshold signal, said further current threshold signal being above said current threshold signal.