Charger and electrical apparatus

• US 6,646,417 B2
• Filed: 11/26/2002
• Issued: 11/11/2003
• Est. Priority Date: 12/04/2001
• Status: Expired due to Fees

• Current Assignee: Pioneer Corporation, Tohoku Pioneer Corporation (Pioneer Corporation)
• Original Assignee: Pioneer Corporation, Tohoku Pioneer Corporation (Pioneer Corporation)
• Inventors: Sato, Koichi, Kato, Yoshinao
• Primary Examiner(s): LUK, LAWRENCE W
• Application Number:
  US10/303,900
• Publication Number:
  US 20030102843A1
• Time in Patent Office: 350 Days
• Field of Search: 320/116, 320/117, 320/120, 320/126, 320/128, 429/96, 429/97, 429/98, 429/99, 429/100
• US Class Current: 320/116
• CPC Class Codes: H02J 7/0029 with safety or protection devices or circuits
• CPC Class Codes: H02J 7/0031 using battery or load disconnect circuits H02J9/002 takes precedence

Abstract

A battery holding portion holds the plurality of secondary batteries in series connection to a charging power source. The power supply to the secondary batteries in series connection is turned on or off by a switching circuit. A control terminal of the switching circuit is connected to a chassis exposure part of one secondary battery, the chassis exposure parts of other secondary batteries being connected to the reference voltage of the charging power source. When the primary battery is mounted, the switching circuit is turned off, because no current path from the charging power source through the plurality of secondary batteries to the reference voltage is established, whereby the batteries are not charged. Hence, it is possible to prevent the charging for the primary battery.

Claims

1. A charger for charging a plurality of secondary batteries, comprising:

a battery holding portion for holding said plurality of secondary batteries in series connection to a charging power source; and

a switching circuit for turning on or off the power supply to said plurality of secondary batteries in series connection from said charging power source, based on a signal to a control terminal,

wherein said control terminal of said switching circuit is connected to a chassis exposure part of one secondary battery, the chassis exposure part of another secondary battery being connected to a reference voltage of said charging power source.

2. The charger according to claim 1, wherein said battery holding portion is a case for accommodating each of said secondary batteries in a state where the plus terminal and the chassis exposure part are exposed outside.

3. The charger according to claim 1, wherein said chassis exposure part is formed on the outer circumference of said secondary battery, and conducts to the minus terminal of said secondary battery.

4. The charger according to claim 1, wherein said switching circuit is a switching transistor, and the base of said switching transistor is connected to the chassis exposure part of said one secondary battery as said control terminal.

5. The charger according to claim 1, further comprising a load circuit connected in parallel to said plurality of secondary batteries in series connection.

6. An electrical apparatus comprising the charger according to any one of claims 1 to 5.