Universal battery charger

• US 20040108834A1
• Filed: 12/01/2003
• Published: 06/10/2004
• Est. Priority Date: 11/29/2002
• Status: Active Grant

• Current Assignee: Hitachi KOKI Company Limited (Koki Holdings Co., Ltd.)
• Original Assignee: Hitachi KOKI Company Limited (Koki Holdings Co., Ltd.)
• Inventors: Funabashi, Kazuhiko, Takano, Nobuhiro
• Granted Patent: US 7,365,515 B2
• Time in Patent Office: Days
• US Class Current: 320/120
• CPC Class Codes: H02J 2207/20 Charging or discharging characterised by the power electronics converter
• CPC Class Codes: H02J 9/005 using a power saving mode for copiers G03G15/5004
• CPC Class Codes: Y02B 70/30 Systems integrating technologies related to power network operation and communication or information technologies for improving the carbon footprint of the management of residential or tertiary loads, i.e. smart grids as climate change mitigation technology in the buildings sector, including also the last stages of power distribution and the control, monitoring or operating management systems at local level
• CPC Class Codes: Y04S 20/20 End-user application control systems

Abstract

To provide a universal battery charger with low power consumption during a standby condition and a rush current suppressing capability at the time of commencement of charging, a voltage slightly larger than a battery voltage is produced and applied to the battery. Thereafter, the highest voltage is produced and applied to the battery to charge the same. When the battery is unloaded from the battery charger, the lowest voltage is produced to save power consumption.

Claims

1. A universal battery charger for charging batteries with different number of cells connected in series, comprising:

a power supply circuit that produces a predetermined number of voltages different in level for applying selected one of the predetermined number of voltages to a battery, the predetermined number of voltages including a highest voltage and a lowest voltage;

a switch that is connected between the power supply circuit and the battery and is turned ON to allow the selected one of the predetermined number of voltages to the battery and OFF to interrupt the power supply circuit from the battery; and

a control device that controls the power supply circuit to produce a voltage to be applied to the battery and also controls the switch so that a rush current does not flow in the battery when the voltage to be applied to the battery is switched from one level to another level.

2. The universal battery charger according to claim 1, further comprising a battery voltage detecting circuit that detects a voltage across the battery, wherein the control device controls the power supply circuit to produce a voltage equal to or close to the voltage detected by the battery voltage detecting circuit and further controls the switch to turn on.

3. The universal battery charger according to claim 2, wherein the control device controls the switch to turn on after expiration of a predetermined period of time from a time when the voltage equal to or close to the voltage detected by the battery voltage detecting circuit is produced by the power supply circuit.

4. The universal battery charger according to claim 3, wherein the voltage close to the voltage detected by the battery voltage detecting circuit is a voltage above and closest to the voltage detected by the battery voltage detecting circuit among the predetermined number of voltages.

5. The universal battery charger according to claim 3, wherein the control device further controls the power supply circuit to produce the highest voltage after the switch is turned on.

6. The universal battery charger according to claim 2, further comprising a battery connection detecting device that detects that the battery is connected for being charged, wherein when the battery connection detecting device detects that the battery is connected, the battery voltage detecting circuit detects a voltage across the battery and the control device controls the power supply circuit to produce the voltage equal to or close to the voltage detected by the battery voltage detecting circuit, and thereafter controls the switch to turn on.

7. The universal battery charger according to claim 6, wherein when the battery connection detecting device detects that the battery is not connected, the control device controls the power supply circuit to produce the lowest voltage.

8. The universal battery charger according to claim 2, wherein when a difference between the voltage detected by the battery voltage detecting circuit and the voltage produced by the power supply circuit falls within a predetermined range, the control device controls the switch to turn on.

9. The universal battery charger according to claim 8, wherein the voltage close to the voltage detected by the battery voltage detecting circuit is a voltage above and closest to the voltage detected by the battery voltage detecting circuit among the predetermined number of voltages.

10. The universal battery charger according to claim 9, wherein the control device further controls the power supply circuit to produce the highest voltage after the switch is turned on.