Battery charger with control circuit
AssigneeMotorola, Inc.
InventorsJohn W. Oglesbee, Michael D. Geren
Life of this patent
Estimating the term…
Abstract
A battery charger (10) is provided with a power supply (26) which is energized by a main winding (22) and a bias winding (24) on the secondary side (18) of an input transformer (14). The charger switches a main voltage level provided at a main voltage output (28) according to a pulse width modulation scheme, and has an output section (36) for filtering the switched voltage. A power switch (38) is coupled between the output section and the main voltage output, and is driven by a bias switch (48) coupled between the control terminal (50) of the power switch, and a bias voltage output (30), which provides a bias voltage level that is higher then the main voltage level by a minimum delta.
Claims13
A battery charger for charging a battery, comprising:
- a power supply, having a return line, for providing a main voltage level at a main voltage output, and a bias voltage level at a bias level output, the bias voltage level being higher than the main voltage level;
- an output section for filtering a switched voltage and providing a regulated current to the battery;
- a power switch, having a control terminal, coupled between the main voltage output and the output section for switching the main voltage level thereby providing the switched voltage;
- a control circuit having a bias switch for switchably connecting the control terminal of the power switch with the bias level output;
- and
- a control network coupled to the control terminal of the power switch.
A battery charger for charging a battery, comprising:
- a transformer having a secondary side having a main winding and a bias winding, the main winding providing voltage for a main voltage output, the bias winding providing voltage for a bias level output, the bias level output having a bias voltage level which is higher than a main voltage level at the main level output;
- an output section, having a series inductor and a shunt freewheel diode, for filtering a switched voltage and providing a regulated current to the battery;
- a power switch, having a control terminal, coupled between the output section and the main voltage output for providing the switched voltage to the output section;
- and
- a control circuit, having a bias switch coupled between the control terminal of the power switch and the bias voltage output.
Dependencies are inferred from the claim text.