BATTERY OPERATING SYSTEM TIMED BY COULOMETERS

• US 3,710,225 A
• Filed: 03/20/1972
• Issued: 01/09/1973
• Est. Priority Date: 03/20/1972
• Status: Expired due to Term

• Current Assignee: Robert W. Herzig
• Original Assignee: Robert W. Herzig
• Inventors: Herzig, Robert W.
• Primary Examiner(s): Miller, J. D.
• Assistant Examiner(s): Hickey, Robert J.
• Application Number:
  US05/235,998
• Time in Patent Office: 295 Days
• Field of Search: 320/5,23,44,45,14,43,9,39,40
• US Class Current: 320/130
• CPC Class Codes: H02J 7/00714 in response to battery charging or discharging current

Abstract

A battery circuit having a drain coulometer and a charge coulometer connected in series so as to alternately plate and deplate and being alternately connectible in parallel with one of a pair of current sensing resistors in series with the battery, each of which accurately reflects the current condition of the battery circuit over a period of time. The drain coulometer integrates a proportional charge current. Thus during the drain mode of the battery, when a predetermined amount will be removed from the drain coulometer and deposited in the charge coulometer. At a critical depletion of coulombs the drain monitor undergoes an impedance transformation which triggers a gate mechanism to actuate switching of the battery to the charge mode. In the charge mode the charge coulometer undergoes the critical coulomb depletion leading to an impedance transformation which in turn triggers a further gate mechanism for actuating switching of the battery back to the drain mode.

Claims

1. A battery operating system timed by coulometers, said system comprising a battery, a load, a charging source, switching means to alternatively connect said battery to said load and said source, a pair of current integrators in the form of a first coulometer to integrate a proportional drain current and a second coulometer to integrate a proportional charge current, said first coulometer and said second coulometer operatively connected in a circuit with said switching means such that a charge being drained from said battery by said load causes said first coulometer to deplate and said second coulometer to plate until an impedance transformation in said first coulometer causes said switching means to connect said battery to said source whereupon a charge from said source to said battery causes said second coulometer to deplate and said first coulometer to plate until an impedance transformation in said second coulometer causes said switching means to connect said battery to said load.

2. In a rechargeable battery control system having a pair of coulometers connected in series so that each coulometer deplates as the other coulometer plates and a source of current for recharging a battery, a battery, a first switching means being operable to connect the battery with a battery load, and a first sensing resistor connected in series with said battery and connectible to said battery load, means connecting said pair of coulometers in parallel with said first sensing resistor during the discharge of said battery including a second switching means having a first contact connectible to said first sensing resistor, whereby closing said first contacts of said first and second switching means and connecting said battery to a load produces an abrupt impedance transformation in one of said coulometers upon passage of a predetermined charge current through the coulometer, said coulometer being connected to gating means to actuate by said abrupt impedance transformation means for switching said first and second switching means to open the respective first contacts and close respective second contacts, the second contact of the first switching means being operable to connect the battery to one terminal of the current source, a second sensing resistor connected in series with the battery and the other terminal of the current source, the second contact of the second switching means being operable to connect the second sensing resistor in parallel with the pair of coulometers whereby the passage of a predetermined charge current through the other of the coulometers produces an impedance transformation, gating means connected to said other coulometer for actuating by said impedance transformation means for switching said first and second switching means to open said respective second contacts and reclose the first contacts.

3. In the system as claimed in claim 2, means joining the sensing resistors and means connecting the junction of the sensing resistors with the coulometers.

4. The system as claimed in claim 3 in which the interconnection of the coulometers at the junction is the negative side of the first sensing resistor during the battery discharge and the positive side of the second sensing resistor during the battery charge.

5. In the system as claimed in claim 2, said first and second sensing resistors having the same values.

6. In the system as claimed in claim 2, a first sensing resistor having a higher value than the second sensing resistor so that a greater ampere-hour charge is provided through the second resistor.

7. In the system as claimed in claim 2, means connecting the first and second switching means with the current source to hold the second contacts closed by the voltage of the current source.