BATTERY-CHARGING SYSTEM WITH VOLTAGE REFERENCE MEANS WITH TWO REFERENCE LEVELS
First Claim
1. A battery-charging control system connectable between a source of charging current and a battery which may have currentconsuming equipment connected thereto, the combination cOmprising:
- a power-controlling device connected between said battery and said source of charging current so that said battery receives current flow from said power controlling device and varies in voltage value;
control circuit means for controlling said power-controlling device to control the battery voltage in accordance with the value established by a voltage reference means, voltage reference means controlling said control circuit means and having a first portion establishing a first reference value related to a first battery voltage and a second portion establishing a second reference value related to a preselected higher battery voltage;
battery voltage-sensing circuit means coupled to said voltage reference means, voltage control circuit means coupled to said voltage reference means and responsive to said battery voltage-sensing circuit means for coupling said second portion in effective circuit relationship in the voltage reference means whereby said control circuit means is selectively controlled at said second reference value upon the battery voltage falling below the first battery voltage value and is maintained at said second reference value until said battery attains a preselected higher voltage value; and
additional voltage control circuit means responsive to said battery voltage-sensing circuit means for decoupling said second portion and coupling only said first portion in effective circuit relationship in said voltage reference means upon the battery attaining the preselected higher voltage value whereby said first reference value selectively controls operation of said control circuit means as long as the battery voltage does not fall below said first voltage reference value.
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Accused Products
Abstract
A battery-charging system wherein a power-controlling device, such as a power transistor, is controlled in accordance with feedback signals representing (1) a charging current exceeding a predetermined maximum reference level and (2) a battery voltage differing from the value associated with a voltage reference, the value of which is changeable between a first value related to a desired battery float voltage and a second value related to a battery voltage a preselected magnitude higher than the desired float voltage; the voltage reference means being arranged to automatically exhibit the second value whenever the battery voltage falls below the desired float voltage and to remain at such second value until the battery has attained the preselected higher voltage when the voltage reference means will exhibit the first value and cause the battery voltage to be regulated at the desired float voltage. A temperature responsive means is included to cause the value of the voltage reference means to change with temperature in a manner corresponding with the typical change in battery voltage with temperature.
24 Citations
17 Claims
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1. A battery-charging control system connectable between a source of charging current and a battery which may have currentconsuming equipment connected thereto, the combination cOmprising:
- a power-controlling device connected between said battery and said source of charging current so that said battery receives current flow from said power controlling device and varies in voltage value;
control circuit means for controlling said power-controlling device to control the battery voltage in accordance with the value established by a voltage reference means, voltage reference means controlling said control circuit means and having a first portion establishing a first reference value related to a first battery voltage and a second portion establishing a second reference value related to a preselected higher battery voltage;
battery voltage-sensing circuit means coupled to said voltage reference means, voltage control circuit means coupled to said voltage reference means and responsive to said battery voltage-sensing circuit means for coupling said second portion in effective circuit relationship in the voltage reference means whereby said control circuit means is selectively controlled at said second reference value upon the battery voltage falling below the first battery voltage value and is maintained at said second reference value until said battery attains a preselected higher voltage value; and
additional voltage control circuit means responsive to said battery voltage-sensing circuit means for decoupling said second portion and coupling only said first portion in effective circuit relationship in said voltage reference means upon the battery attaining the preselected higher voltage value whereby said first reference value selectively controls operation of said control circuit means as long as the battery voltage does not fall below said first voltage reference value.
- a power-controlling device connected between said battery and said source of charging current so that said battery receives current flow from said power controlling device and varies in voltage value;
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2. The battery-charging control system recited in claim 1 wherein said voltage reference means is comprised of temperature responsive elements operative to cause the values of said voltage reference to change in a predetermined manner with changes in temperature.
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3. The battery-charging control system recited in claim 1 further including current limiting circuit means coupled to and controlling said control circuit means for limiting the maximum charging current to a predetermined level.
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4. The battery-charging control system recited in claim 1 further including adjusting means coupled to said battery voltage-sensing circuit means to adjust the same to accommodate different size batteries, and load-limiting coupling circuit means for coupling said voltage reference means to said battery voltage-sensing circuit means for minimizing the loading effect thereon.
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5. The battery-charging control system recited in claim 1 wherein said first portion of said voltage reference means includes a Zener diode operatively coupled to said battery voltage sensing circuit means for essentially establishing the first voltage reference value and the voltage control circuit means comprises a first voltage control transistor responsive to current flow through the Zener diode to couple said second portion of the voltage reference means in effective circuit relationship in controlling the operation of the control circuit means.
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6. The battery-charging control system recited in claim 2 wherein said second portion of said voltage reference means includes an adjustable resistor and parallel connected latching transistor for substantially shunting said adjustable resistor upon being rendered conductive with said adjustable resistor serving to establish the second higher reference voltage with the latching transistor in the nonconducting condition, and the additional voltage control circuit means includes a second voltage control transistor responsive to current flow through said first voltage control transistor for controlling turn-on and turnoff of said latching transistor.
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7. The battery-charging control system recited in claim 6 further including current limiting circuit means coupled to and controlling said control circuit means for limiting the maximum charging current to a predetermined lEvel.
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8. The battery-charging control system recited in claim 7 wherein said voltage reference means is comprised of temperature responsive elements operative to cause the values of said voltage reference to change in a predetermined manner with changes in temperature.
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9. The battery-charging control system recited in claim 8 further including adjusting means coupled to said battery voltage sensing circuit means to adjust the same to accommodate different size batteries, and load-limiting coupling circuit means for coupling said voltage reference means to said battery voltage sensing circuit means for minimizing the loading effect thereon.
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10. An automatic battery charging and voltage regulating system connectable between a source of voltage and a battery which may have current consuming equipment connected thereto, comprising:
- a power transistor connected between said voltage source and said battery so that said battery receives current flow from said source through said power transistor and varies in voltage value;
battery voltage-sensing circuit means;
voltage reference means responsive to said battery voltage-sensing circuit means and including a first portion capable of selectively providing a first voltage reference value related to a first battery voltage value and a second portion coacting with said first portion and capable of selectively providing a second voltage reference value related to a preselected higher battery voltage value;
control circuit means responsive to the voltage reference means to controlling the conductivity of said power transistor to control the battery voltage in accordance with the value established by said voltage reference means;
a first voltage control transistor connected with both said first and second portions of said voltage reference means for selectively connecting both portions thereof in effective circuit relationship to establish the second voltage reference value whenever the battery voltage is below the first voltage reference value as established by said first portion and for maintaining said second voltage reference value until the battery attains the preselected higher voltage value; and
a second voltage control transistor responsive to a preselected value of current flow through said first voltage control transistor for effectively disconnecting said second portion from said voltage reference means to thereby establish the first voltage reference value for controlling the control circuit means in response to the battery attaining the preselected higher second reference voltage value.
- a power transistor connected between said voltage source and said battery so that said battery receives current flow from said source through said power transistor and varies in voltage value;
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11. The automatic battery-charging and voltage-regulating system recited in claim 10 further including current-limiting circuit means operatively connected with and controlling said control circuit means for limiting the maximum output current of the system to a predetermined level.
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12. The automatic battery-charging and voltage-regulating system recited in claim 11 wherein said voltage reference means is comprised of temperature responsive elements designed to cause the value of said voltage reference means to change in a predetermined manner with changes in temperature.
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13. The battery-charging control system recited in claim 12 further including adjusting means coupled to said battery voltage-sensing circuit means to adjust the same to accommodate different size batteries, and load-limiting coupling circuit means for coupling said voltage reference means to said battery voltage-sensing circuit means for minimizing the loading effect thereon.
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14. In a battery-charging system of the type including a transformer and a rectifier to provide a charging current source from an alternating current voltage supply, a control system for automatically bringing the battery to its fully charged condition and thereafter regulating the voltage value to maintain the battery in its fully charged condition comprising:
- a power transistor connected in series circuit relationship between said charging current source and said battery so that said bAttery receives current flow from said source through said power transistor and varies in voltage value;
a second transistor connected to said power transistor at the base thereof and providing base drive current for said power transistor for controlling the conductivity thereof;
a third transistor connected to said second transistor at the base thereof and arranged to bypass base current from said second transistor to control its conductivity;
current level-detecting and limiting means including current sensing means and a fourth transistor being responsive to the current-sensing means and connected to said third transistor at the base thereof, said fourth transistor being arranged to become conducting when the charging current sensed by said sensing means reaches a predetermined level and provides base drive current for said third transistor to limit current flow through said power transistor;
voltage reference means providing a voltage-regulating control signal to the base of said third transistor in conjunction with said current level detecting and limiting means, said voltage reference means comprising first and second voltage reference portions, said first portion provided by a voltage breakover device and the P-N junction barrier voltage of a first voltage control transistor and said second portion being provided by an adjustable resistor;
a latching transistor connected in series with said first voltage control transistor and in shunt with said second reference portion so that said second reference portion is made part of or removed from the effective value of said voltage reference means as said latching transistor is in a nonconducting and conducting condition, respectively;
a second voltage transistor responsive to current flow through said first voltage control transistor and arranged to become conducting upon said first voltage control transistor being rendered conductive and connected in regenerative relationship with said latching transistor to cause said latching transistor to quickly become saturated after said first and second voltage control transistors become conductive;
circuit means coupling said first and second voltage control transistors to the base of said third transistor for controlling operation thereof in conjunction with said current level-detecting and limiting means;
battery voltage-sensing circuit means for deriving a voltage signal proportional to the battery voltage; and
means applying the voltage signal derived from said battery voltage sensing means to said voltage reference means.
- a power transistor connected in series circuit relationship between said charging current source and said battery so that said bAttery receives current flow from said source through said power transistor and varies in voltage value;
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15. The battery-charging system recited in claim 14 wherein at least the voltage sensitive breakover device connected with said voltage reference means is temperature responsive to cause the value thereof to change in a predetermined manner with changes in temperature.
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16. The battery-charging system recited in claim 15 wherein at least one additional temperature responsive P-N junction device is connected in series circuit relationship with said voltage breakover device.
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17. The battery-charging control system recited in claim 16 wherein adjusting means are provided to the battery voltage sensing circuit means to adjust the same to accommodate different size batteries, and wherein the means for applying the voltage signal derived from the battery voltage sensing circuit means to the voltage reference means comprises load-limiting coupling circuit means for minimizing the loading effect of the voltage reference means on the battery voltage-sensing circuit means.
Specification