BATTERY CHARGING CIRCUIT

• US 20100327817A1
• Filed: 02/05/2009
• Published: 12/30/2010
• Est. Priority Date: 02/06/2008
• Status: Active Grant

• Current Assignee: Shindengen Electric Manufacturing Company Limited
• Original Assignee: Shindengen Electric Manufacturing Company Limited
• Inventors: Tabuta, Makoto
• Granted Patent: US 8,415,929 B2
• Time in Patent Office: Days
• US Class Current: 320/148
• CPC Class Codes: H01M 10/44 Methods for charging or discharging circuits for charging H02J7/00
• CPC Class Codes: H02J 7/1484 by commutation of the output windings of the generator
• CPC Class Codes: H02J 7/1492 by means of controlling devices between the generator output and the battery
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02T 10/92 Energy efficient charging or discharging systems for batteries, ultracapacitors, supercapacitors or double-layer capacitors specially adapted for vehicles

Abstract

A battery charging circuit comprises: a rectifier circuit (2) for rectifying a three-phase AC voltage outputted from an electric power generator (1) and generating a charge voltage for charging a battery (B); a voltage detection circuit (4) for detecting that the voltage of the battery (B) exceeds a predetermined voltage; a switching circuit (3) for, in an off-state, charging the battery (B) through the rectifier circuit (2) and, in an on-state, short-circuiting the electric power generator (1) through the rectifier circuit (2); a switch control circuit (5) for, when it is detected by the voltage detection circuit (4) that the voltage of the battery (B) exceeds the predetermined voltage, bringing the switching circuit (3) into the on-state; and a control circuit (6) for allowing the switch control circuit (5) to subsequently perform a control for bringing the switching circuit (3) into the off-state.

Claims

1. A battery charging circuit comprising:

a rectifier circuit that rectifies a three-phase alternate-current voltage outputted from an electric power generator and generates a charge voltage for charging a battery;

a voltage detection circuit that detects that a voltage of the battery becomes equal to or higher than a predetermined voltage;

a switching circuit that charges, in an off-state, the battery through the rectifier circuit and that short-circuits, in an on-state, the electric power generator through the rectifier circuit;

a switch control circuit that switches the switching circuit to the on-state when the voltage detection circuit detects that the voltage of the battery becomes equal to or higher than the predetermined voltage; and

a control circuit that controls the switching circuit to switch from the on-state to the off-state and to maintain the off-state,

wherein the control circuit comprises a capacitor that is charged when the switch control circuit controls the switching circuit to switch to the on-state, the capacitor discharging when the switch control circuit controls the switching circuit to switch to the off-state,

the voltage detection circuit comprises a first transistor, a base of the first transistor being reverse-biased by the capacitor discharging, and

the switch control circuit comprises a second transistor, a base of the second transistor being connected to a collector of the first transistor, the switch control circuit controlling the on-state and the off-state of the switching circuit based on a collector current through the collector.

2. (canceled)

3. A battery charging circuit comprising:

a rectifier circuit that rectifies a three-phase alternate-current voltage outputted from an electric power generator and generates a charge voltage for charging a battery;

a voltage detection circuit that detects that a voltage of the battery becomes equal to or higher than a predetermined voltage;

a switching circuit that charges, in an off-state, the battery through the rectifier circuit and that short-circuits, in an on-state, the electric power generator through the rectifier circuit;

a switch control circuit that switches the switching circuit to the on-state when the voltage detection circuit detects that the voltage of the battery becomes equal to or higher than the predetermined voltage; and

a control circuit that controls the switching circuit to maintain the on-state when the switching circuit is in the on-state and to maintain the off-state when the switching circuit is in the off-state,

wherein the control circuit comprises a capacitor that is charged when the switch control circuit controls the switching circuit to switch to the on-state, the capacitor discharging when the switch control circuit controls the switching circuit to switch to the off-state,

the voltage detection circuit comprises a first transistor, a base of the first transistor being reverse-biased by the capacitor discharging, and

the switch control circuit comprises a second transistor, a base of the second transistor being connected to a collector of the first transistor, the switch control circuit controlling the on-state and the off-state of the switching circuit based on a collector current through the collector.

4. (canceled)

5. (canceled)

6. (canceled)