Battery protecting system in a car stereo

• US 5,138,246 A
• Filed: 01/02/1991
• Issued: 08/11/1992
• Est. Priority Date: 06/21/1990
• Status: Expired due to Fees

• Current Assignee: Pioneer Electronics (USA) Incorporated (Pioneer Corporation)
• Original Assignee: Pioneer Electronics Corporation (Pioneer Corporation)
• Inventors: Kobayashi, Hiroshi
• Primary Examiner(s): HICKEY, ROBERT
• Application Number:
  US07/636,790
• Time in Patent Office: 587 Days
• Field of Search: 320/13, 320/48, 307/10.7
• US Class Current: 320/136
• CPC Class Codes: B60R 16/03 for supply of electrical power to vehicle subsystems or for circuit arrangements for charging batteries H02J7/00
• CPC Class Codes: H02J 2310/46 for ICE-powered road vehicles
• CPC Class Codes: H02J 7/0031 using battery or load disconnect circuits H02J9/002 takes precedence
• CPC Class Codes: Y10S 320/21 State of charge of battery

Abstract

A discharge detector circuit is provided for detecting a discharging state of a battery of a motor vehicle. A lower limit voltage of the battery which is a lower limit voltage for starting an engine of the vouching is detected. Power supply to a car stereo is cut off when the discharge of the battery is detected and the battery voltage decreases to the lower limit voltage.

Claims

1. A battery protecting system in a car stereo mounted on a motor vehicle, comprising:

charge-level detector means for detecting a state of charge of a battery of the motor vehicle and for producing a discharge signal;

first limit detector means for detecting a first lower limit voltage of the battery which is the lower limit voltage for starting an engine of the vehicle and for producing a first limit signal when battery voltage is lower than the first lower limit voltage and higher than a second lower limit voltage which is lower than the first lower limit voltage and is a lower limit voltage for operating the car stereo;

first cutting means responsive to both of the discharge signal and the first limit signal for cutting off power supply to the car stereo;

second limit detector means for detecting the second lower limit voltage of the battery and for producing a second limit signal when the battery voltage is lower than the second lower limit voltage; and

second cutting means responsive to the second limit signal for cutting off the power supply to the car stereo.

2. The system according to claim 1 wherein the charge-level detector means includes detector means for detecting closing.

3. The system according to claim 2 wherein the first limit detector means includes means for detecting output voltage of the battery.

4. The system according to claim 3 wherein the second limit detector means include means for detecting output voltage of the battery.

5. The system according to claim 4 wherein the first limit detector means includes a timer.