Patent ID: 6433516
Filing Date: 2002-08-13
Classification: H02J

Abstract:
A temperature stabilized, constant current source battery charger suitable for charging a fully discharged battery, comprising:a current based feedback control circuit responsive to small signal changes in a battery charging current wherein the feedback control circuit maintains the battery charging current within a predetermined range of current values at a particular operating temperature; a temperature compensation circuit coupled from the feedback control circuit that is responsive to a temperature change having a sensing resistor of a given resistor technology coupled from at least one positive temperature coefficient voltage source and at least one negative temperature coefficient current source arranged to provide said sensing resistor with a temperature stabilized control current such that temperature dependencies of the negative temperature coefficient current source substantially countervails the at least one positive temperature coefficient voltage source such that a sense voltage developed by the sensing resistor is substantially constant over a predetermined operating range of temperatures; and a bias resister coupled to the temperature compensation circuit arranged to provide a bias current to the temperature compensation circuit based upon a supply voltage such that the temperature compensation circuit is operative when the battery is fully discharged.