Battery charger

• US 20070069688A1
• Filed: 09/26/2006
• Published: 03/29/2007
• Est. Priority Date: 09/29/2005
• Status: Active Grant

• Current Assignee: Sanyo Electric Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Sanyo Electric Company Limited (Panasonic Holdings Corporation)
• Inventors: Satsuma, Eiji
• Granted Patent: US 7,741,807 B2
• Time in Patent Office: Days
• US Class Current: 320/110
• CPC Class Codes: H02J 7/0042 characterised by the mechanical construction

Abstract

The type of the attached batteries is determined by decision switch mechanisms. A protruding region is established in the attachment section to provide contact between charging terminals and the electrodes of short batteries. A stepped shelf region is established with the protruding region, and long batteries are mounted inside the attachment section on top of the stepped shelf region. Charging terminals are disposed in electrode alignment surface of the stepped shelf region, and decision switch mechanisms are housed inside the stepped shelf region. A decision switch mechanism is a switch that switches when pressed by the battery electrode of either a long battery or a short battery loaded in the attachment section. The control circuit switches charging current between a first charging current and a second charging current depending on the OFF or ON state of the decision switch mechanisms.

Claims

1. A battery charger comprising a case that has a battery attachment section to attach long batteries and short batteries, charging terminals to contact electrodes at both ends of long batteries and short batteries attached in the battery attachment section and to supply charging current to those batteries, decision switch mechanisms to distinguish the types of batteries attached in the battery attachment section, and a control circuit to control charging current for batteries attached in the battery attachment section based on signals from the decision switch mechanisms;

a first pair of charging terminals to charge long batteries and a second pair of charging terminals to charge short batteries are disposed in opposing positions in the battery attachment section;

a protruding region is established in the battery attachment section to provide contact between the charging terminals and electrodes of short batteries, which are not as long as long batteries, stepped shelf region is established with the protruding region in electrode attachment section, charging terminals are disposed at surface of the stepped shelf region that align opposite electrodes, and the decision switch mechanisms are disposed inside the stepped shelf region;

a decision switch mechanism is a switch that switches when pressed by the battery electrode of either a long battery or a short battery attached in the battery attachment section, and the control circuit switches charging current between a first charging current and a second charging current to charge long batteries and short batteries depending on the OFF or ON state of the decision switch mechanism.

2. A battery charger as recited in claim 1 wherein the charging terminals are provided with common charging terminals disposed at one end of the battery attachment section to contact electrodes at one end of long batteries and short batteries, long battery charging terminals to contact electrodes at the other end of long batteries attached in the battery attachment section, and short battery charging terminals to contact electrodes at the other end of short batteries attached in the battery attachment section;

long battery charging terminals are disposed in positions facing the electrodes of long batteries set on top of the stepped shelf region, and short battery charging terminals are disposed at surfaces of the protruding region of the stepped shelf region that align opposite electrodes.

3. A battery charger as recited in claim 2 wherein the decision switch mechanism is made up of a short battery charging terminal and a long battery charging terminal.

4. A battery charger as recited in claim 3 wherein the short battery charging terminal is a resiliently deforming sheet metal piece, the short battery charging terminal is disposed in a position such that it is pressed upon by the electrode of a short battery attached in the battery attachment section and contacts the long battery charging terminal, and it is separated from the long battery charging terminal in a non-contact state when not pressed by a short battery;

when a short battery is attached in the battery attachment section, the short battery presses against the short battery charging terminal causing it to contact the long battery charging terminal, the control circuit detects contact between the short battery charging terminal and long battery charging terminal, and the short battery is charged with the second charging current;

when a short battery is not attached in the battery attachment section and a long battery is attached, a short battery does not press against the short battery charging terminal, the short battery charging terminal is separated from the long battery charging terminal, the control circuit detects a non-contact state between the short battery charging terminal and long battery charging terminal, and the long battery is charged with the first charging current.

5. A battery charger as recited in claim 4 wherein the long battery charging terminal is disposed behind the short battery charging terminal inside a stepped shelf region, a short battery attached in the battery attachment section presses the short battery charging terminal toward the long battery charging terminal, and causes the short battery charging terminal to contact the long battery charging terminal.

6. A battery charger as recited in claim 3 wherein the long battery charging terminal is a resiliently deforming sheet metal piece, the long battery charging terminal is disposed in a position such that it is pressed upon by the electrode of a long battery attached in the battery attachment section and contacts the short battery charging terminal, and it is separated from the short battery charging terminal in a non-contact state when not pressed by a long battery;

when a long battery is attached in the battery attachment section, the long battery presses against the long battery charging terminal causing it to contact the short battery charging terminal, the control circuit detects contact between the long battery charging terminal and short. battery charging terminal, and the long battery is charged with the first charging current;

when a long battery is not attached in the battery attachment section and a short battery is attached, a long battery does not press against the long battery charging terminal, the long battery charging terminal is separated from the short battery charging terminal, the control circuit detects a non-contact state between the long battery charging terminal and short battery charging terminal, and the short battery is charged with the second charging current.

7. A battery charger as recited in claim 3 wherein the control circuit detects short battery charging terminal voltage to detect contact or non-contact between the short battery charging terminal and long battery charging terminal.

8. A battery charger as recited in claim 7 wherein power supply voltage Vcc is supplied to the long battery charging terminal via a pull-up resistor R.

9. A battery charger as recited in claim 3 wherein the control circuit detects long battery charging terminal voltage to control long battery charging current.

10. A battery charger as recited in claim 9 wherein power supply voltage Vcc is supplied to the short battery charging terminal via a pull-up resistor R.

11. A battery charger as recited in claim 1 wherein the battery attachment section of the case has battery pockets that allow four rows of long batteries or short batteries to be loaded.

12. A battery charger as recited in claim 1 wherein temperature sensors are provided in the charging terminals.

13. A battery charger as recited in claim 10 wherein a temperature sensor is sandwiched between the end of a charging terminal and the backside of a spring-action arm of the charging terminal.