CIRCUIT FOR A SMALL ELECTRIC APPLIANCE WITH AN ACCUMULATOR AND METHOD FOR MEASURING A CHARGING CURRENT

摘要

The invention relates to a circuit for a battery-operated small electric appliance having a rechargeable battery (B), a control circuit (uC) for measuring the charging current of the rechargeable battery (B), and a DC-DC converter (DC/DC) which supplies the control circuit (uC) and possibly further loads from the battery. The circuit has further a current sensing resistor (R1), whose one end lies at a reference potential and whose other end is connected to the battery (B). The control circuit (uC) has a terminal which is at reference potential and a measurement input which is related to the reference potential. A method for measuring the charging current of the rechargeable battery includes that said control circuit (uC) measures the charging current only when the at least one further load is switched off or the control circuit (uC) provides at least one correction value to the measured charging current when the at least one further load is not is switched off during the current measurement.