Battery monitor with automatic scale and recycle prevents

• US 3,979,657 A
• Filed: 08/22/1975
• Issued: 09/07/1976
• Est. Priority Date: 05/15/1973
• Status: Expired due to Term

• Current Assignee: Westinghouse Electric Company LLC (Brookfield Asset Management Incorporated)
• Original Assignee: Westinghouse Electric Company LLC (Brookfield Asset Management Incorporated)
• Inventors: Yorksie, Daniel S.
• Primary Examiner(s): Miller J D
• Assistant Examiner(s): Hickey, Robert J.
• Application Number:
  US05/607,010
• Time in Patent Office: 382 Days
• Field of Search: 320/13, 320/39, 320/40, 320/48, 340/248 B, 340/249, 317/9 BP
• US Class Current: 320/136
• CPC Class Codes: B60L 58/13 Maintaining the SoC within a determined range
• CPC Class Codes: G01R 19/16542 for batteries charge condition monitoring in G01R31/36
• CPC Class Codes: H02J 9/002 in which a reserve is maintained in an energy source by disconnecting non-critical loads, e.g. maintaining a reserve of charge in a vehicle battery for starting an engine
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/92 Energy efficient charging or discharging systems for batteries, ultracapacitors, supercapacitors or double-layer capacitors specially adapted for vehicles
• CPC Class Codes: Y10S 320/21 State of charge of battery

Abstract

A monitor for disabling a selected operative function of the battery powered vehicle when the battery reaches a predetermined discharge state is disclosed. The discharge state of the battery is determined by continuously monitoring the terminal voltage of the battery. Automatic scaling circuitry is included so that the monitor automatically adjusts to the range which is appropriate for the battery being monitored. Two warning signals are generated with each warning signal indicating a progressively lower discharge state of the battery. After the second warning signal has been on for a predetermined time period, a selected operative function of the vehicle is disabled. If the vehicle is a fork-lift truck for example, the lift mechanism might be disabled however the main drive motor could remain operative so that the truck could be returned to the battery charging station. The monitor also prohibits the disabled function from being reenergized except when a fully charged battery is installed in the vehicle.

Claims

1. A circuit for monitoring the terminal voltage of an electrical energy source for an electrically powered vehicle, comprising in combination:

(a) automatic scaling means for monitoring the terminal voltage of said energy source and adjusting an attenuator to a range appropriate for the energy source being monitored to produce a first signal, said first signal having a predetermined relationship to the terminal voltage of said energy source, said scaling means also including a filter to assure that said range changing means does not respond to rapid changes in the terminal voltage of said energy source;

(b) comparator and timing means for comparing the magnitude of said first signal to a reference signal to determine if said first signal decreases below a first predetermined level and remains below a second predetermined level for a predetermined time interval to generate and initiate disable signal; and

(c) first disable means for disabling a selected operative function of said vehicle in response to said initiate disable signal.

2. The circuit defined by claim 1 further including means for initiating a warning signal whenever said first signal is below said first predetermined level.

3. The circuit defined by claim 1 further including means for retaining a selected operative function of the vehicle in a disabled condition until the terminal voltage of said energy source exceeds a second predetermined level.

4. The circuit defined by claim 3 further including second disable means for disabling said selected operative function without substantial delay if the terminal voltage of said battery falls below a third predetermined level.

5. The circuit defined by claim 1 wherein said automatic scaling circuit comprises:

a. first and second resistance resistors series coupled to form a divider network;

b. switching means permitting the current flowing in selected elements of said first network to relatively flow through said second network to change the scale of said attenuator.

6. A circuit for monitoring the terminal voltage of an electrical energy source for an electrically powered vehicle, comprising in combination:

(a) automatic scaling means for monitoring the terminal voltage of said energy source and for adjusting an attenuator to produce a first signal, said first signal having a predetermined relationship to the terminal voltage of said energy source, said scaling means also including a filter to assure that said range changing means does not respond to rapid changes in the terminal voltage of said energy source;

(b) compare and timing means for comparing the magnitude of said first signal to a second signal to determine if the terminal voltage of said energy source decreases below a first predetermined value and remains below a second predetermined level for a predetermined time interval to generate a disable initiate signa;

(c) first disable means for selectively disabling a selected operative function of said vehicle in response to said disable initiate signal; and

(d) means for selectively re-enabling said selected operative function if the terminal voltage of said energy source exceeds a third predetermined level.

7. A circuit for monitoring the terminal voltage of an electrical energy source for an electrically powered vehicle, comprising in combination:

(a) automatic scaling means for monitoring the terminal voltage of said energy source and for adjusting an attenuator to produce a first signal, said first signal having a predetermined relationship to the terminal voltage of said energy source;

(b) means for delaying the operation of a selected function of said vehicle until said automatic scaling means determines the expected terminal voltage of said energy source;

(c) compare and timing means for comparing the magnitude of said first signal to a reference signal to determine if the terminal voltage of said energy source decreases below a first predetermined value and remains below a predetermined level for a predetermined time interval to generate a disable ititiate signal;

(d) first disable means for selectively disabling a selected operative function of said vehicle in response to said disable initiate signal.

8. A circuit for monitoring the terminal voltage of an electrical energy source for an electrically powered vehicle, comprising in combination;

(a) automatic scaling means for monitoring the terminal voltage of said energy source and for adjusting an attenuator to produce a first signal, said first signal having a predetermined relationship to the terminal voltage of said energy source, (b) means for delaying the operation of a selected function of said vehicle until said automatic scaling means determines the expected terminal voltage of said energy source;

(c) compare and timing means for comparing the magnitude of said first signal to a second signal to determine if said first signal decreases below a first predetermined value and remains below a second predetermined level for a predetermined time interval to generate a disable initiate signal;

(d) first disable means for selectively disabling a selected operative function of said vehicle in response to said disable initiate signal; and

(e) means for selectively re-enabling said selected operative function if the terminal voltage of said energy source exceeds a predetermined level.

9. A circuit for monitoring the terminal voltage of an electrical energy source for electrically powered apparatus comprising in combination:

(a) automatic scaling means for monitoring the terminal voltage of said energy source and for adjusting an attenuator to produce a first signal, said first signal having a predetermined relationship to the terminal voltage of said energy source;

(b) means for delaying the operation of a selected function of said electrically powered apparatus until said automatic scaling means determines the expected terminal voltage of said energy source;

(c) compare and timing means for comparing the magnitude of said first signal to a second signal to determine if the terminal voltage of said energy source decreases below a first predetermined value and remains below a second predetermined level for a predetermined time interval to generate a disable initiate signal;

(d) first disable means for selectively disabling a selected operative function of said vehicle in response to said disable initiate signal; and

(e) means for selectively re-enabling said selected operative function if the terminal voltage of said energy source exceeds a third predetermined level.