Apparatus for preventing over-discharge

• US 5,929,603 A
• Filed: 01/28/1997
• Issued: 07/27/1999
• Est. Priority Date: 02/05/1996
• Status: Expired due to Term

• Current Assignee: FDK Corporation (Fujitsu Limited)
• Original Assignee: FDK Corporation (Fujitsu Limited)
• Inventors: Suzuki, Tetsuya, Yamada, Katsuo, Wakao, Shoichi, Ohishi, Kozi, Nakao, Fumiaki
• Primary Examiner(s): Wong, Peter S.
• Assistant Examiner(s): SHIN, KYUNG E
• Application Number:
  US08/791,045
• Time in Patent Office: 910 Days
• Field of Search: 320/135, 320/136, 320/134, 320/116, 320/118, 324/429, 324/433, 324/434, 429/90, 429/91, 429/92, 429/93, 307/10.7
• US Class Current: 320/136
• CPC Class Codes: H02J 7/0014 Circuits for equalisation of charge between batteries
• CPC Class Codes: H02J 7/00306 Overdischarge protection

Abstract

An over-discharge prevention apparatus comprising:

a voltage detection device 2 for detecting electric voltages of both ends of a electric storage element (B) and outputting a discharge finishing signal (PFD) when a discharge extinction voltage (VL) is detected;

a discharge controlling device 3 for delaying the detected output of the voltage detection device 2 for a predetermined time (Td); and

a switching device 1 connected in series with the electric storage element (B), the switching device being set to an OFF state by a delay signal of the discharge controlling device.

Claims

1. An over-discharge prevention apparatus for an external apparatus, comprising:

voltage detection means for detecting electric voltages of each battery cell of a multi-cell structure forming a battery package, said voltage detection means obtaining a logical sum of the detected electric voltages when a discharge finishing voltage is detected to transmit a discharge finishing signal (PFD) for the battery package to the external apparatus;

discharge controlling means for delaying a detected output of the voltage detection means for a predetermined time (Td); and

switching means connected in series with the battery package, the switching means being set to an OFF state by a delay signal of the discharge controlling means after the discharge finishing signal is transmitted to the external apparatus.

2. An over-discharge prevention apparatus for an external apparatus, comprising:

voltage detection means for detecting electric voltages of each battery cell of a multi-cell structure forming a battery package, said voltage detection means obtaining a logical sum of the detected electric voltages when a discharge finishing voltage is detected to transmit a discharge finishing signal (PFD) for the battery package to the external apparatus;

remote controlling means for effectuating an external power cut-off signal (RST) after the discharge finishing signal (PFD) is transmitted; and

switching means connected in series with the battery package, the switching means being set to an OFF state by an OFF output signal (S1) of the remote controlling means after the discharge finishing signal is transmitted to the external apparatus.