CONTROL CIRCUIT OPERABLE TO CHARGE A BATTERY AT MULTIPLE CHARGE RATES

• US 20110215770A1
• Filed: 03/08/2010
• Published: 09/08/2011
• Est. Priority Date: 03/08/2010
• Status: Active Grant

• Current Assignee: Masco Canada Limited (Masco Corporation)
• Original Assignee: Masco Canada Limited (Masco Corporation)
• Inventors: Belz, Jeffrey John
• Granted Patent: US 8,841,879 B2
• Time in Patent Office: Days
• US Class Current: 320/160
• CPC Class Codes: H02J 2207/10 Control circuit supply, e.g. means for supplying power to the control circuit
• CPC Class Codes: H02J 2207/40 adapted for charging from various sources, e.g. AC, DC or multivoltage
• CPC Class Codes: H02J 7/00 Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
• CPC Class Codes: H02J 7/0068 Battery or charger load switching, e.g. concurrent charging and load supply H02J7/0013 takes precedence
• CPC Class Codes: H02J 7/007182 in response to battery voltage
• CPC Class Codes: H02J 7/04 Regulation of charging current or voltage

Abstract

A method of charging a battery at multiple charges rates includes determining a type of power source connected to a charging circuit and determining a voltage of a battery to be charged by the power source. A desired charging voltage is determined in response to the power source type and the battery voltage. A difference between the desired charging voltage and the battery voltage is determined. A digital potentiometer is selectively commanded to adjust the desired charging voltage to vary the difference and alter a charging rate of the battery, such that the difference is increased to increase the charging rate or is decreased to decrease the charging rate.

Claims

1. A method of charging a battery at multiple charge rates, comprising:

determining a type of power source connected to a charging circuit;

determining a voltage of a battery to be charged by the power source;

determining a desired charging voltage in response to the power source type and the battery voltage;

determining a difference between the desired charging voltage and the battery voltage; and

selectively commanding a digital potentiometer to adjust the desired charging voltage to vary the difference and alter a charging rate of the battery, such that the difference is increased to increase the charging rate or is decreased to decrease the charging rate.

2. The method of claim 1, wherein said steps of determining a type of power source, determining a desired charging voltage, determining a difference between the desired charging voltage and the battery voltage, and selectively commanding a digital potentiometer to adjust the desired charging voltage are only performed if a voltage of the power source exceeds a voltage threshold.

3. The method of claim 2, wherein the voltage threshold is implemented by a zener diode oriented to prevent a flow of current from the power source unless a voltage of the power source exceeds a breakdown voltage of the zener diode.

4. The method of claim 1, including:

preventing the charging voltage from charging the battery in response to a voltage of the power source being less than a voltage threshold or in response to a voltage of the battery being equal to or greater than a predefined battery charging threshold.

5. The method of claim 4, wherein said preventing the charging voltage from charging the battery includes disabling a charge enable circuit, the method including:

enabling the charge enable circuit to charge the battery using a charging current from the charging voltage.

6. The method of claim 1, wherein said step of selectively adjusting the desired charging voltage to vary the difference and alter a charging rate of the battery includes:

comparing a power draw on the power source at the charging rate to a maximum rated power output of the power source; and

decreasing the charging rate to prevent the power source from exceeding its maximum power output in response to the charging current causing the power source to exceed its maximum power output.

7. The method of claim 1, wherein said determining a desired charging voltage in response to the power source type and the battery voltage includes defining the desired charging voltage to effect a variable charging rate that varies depending on a frequency of current from the power source at a given battery voltage.

8. The method of claim 1, wherein said determining a desired charging voltage in response to the power source type and the battery voltage includes defining the desired charging voltage to effect a constant charging rate in response to the power source being an AC power source having a constant output voltage.

9. The method of claim 1, wherein said determining a type of power source connected to a charging circuit includes:

determining a frequency of current from the power source;

defining the power source to be a first type of power source in response to the frequency being within a first range; and

defining the power source to be a second type of power source in response to the frequency being within a second range that is higher than the first range.

10. A control circuit operable to charge a battery at multiple charge rates, comprising:

a power source having a power source voltage;

a voltage regulator producing a charging voltage in response to the power source voltage exceeding a voltage threshold;

a digital potentiometer providing a feedback voltage to the voltage regulator such that the digital potentiometer is operable to dynamically adjust the charging voltage and a corresponding charging rate of the charging voltage;

a charge enable circuit operable to enable or disable a charging current of the charging voltage from charging a battery;

a microcontroller operable to control the charge enable circuit and the digital potentiometer, wherein the microcontroller determines a type of power source, determines the charging voltage and corresponding charging rate in response to the type of power source and a voltage of the battery, and commands the digital potentiometer to adjust the charging voltage such that a difference between the charging voltage and a voltage of the battery may be varied to alter a charging rate of the battery.

11. The circuit of claim 10, wherein the power source is one of a generator or an AC power source having a constant output not dependent upon environmental conditions, and wherein the microcontroller assigns a dynamic charging voltage and dynamic charging rate in response to detecting the generator, the dynamic charging voltage varying depending on a frequency of current from the power source at a given battery voltage.

12. The circuit of claim 11, wherein the generator is a hydroelectric generator that harvests energy from a flow of a fluid, and wherein the battery powers a electronic faucet load that controls a flow of the fluid.

13. The circuit of claim 10, wherein the microcontroller adjusts the charging voltage such that the charging rate corresponding to the charging voltage does not cause the detected power source to exceed its maximum power output.

14. The circuit of claim 10, wherein the microcontroller determines the type of power source in response to a frequency of current from the power source voltage being within one of a first range, or a second range different than the first range.

15. The circuit of claim 10, wherein the voltage regulator is a step-down voltage regulator, and wherein the charging voltage is less than the power source voltage.

16. The circuit of claim 10, including a zener diode located between the power source and the voltage regulator, the zener diode being oriented to prevent a flow of current from the power source to the voltage regulator unless a voltage of the power source exceeds a breakdown voltage of the zener diode.

17. A method of charging a battery at multiple charge rates, comprising:

determining a difference between a desired charging voltage from a power source and a voltage of a battery to be charged; and

selectively adjusting the desired charging voltage to vary the difference and alter a charging rate of the battery, such that the difference is increased to increase the charging rate or is decreased to decrease the charging rate; and

verifying that the charging rate does not cause the power source to exceed its maximum power output.

18. The method of claim 17, including:

determining a type of power source connected to a charging circuit;

determining a voltage of a battery to be charged by the power source; and

determining a desired charging voltage in response to the power source type and the battery voltage.

19. The method of claim 17, wherein said determining a type of power source connected to a charging circuit includes:

determining a frequency of current from the power source;

defining the power source to be a first type of power source in response to the frequency being within a first range; and

defining the power source to be a second type of power source in response to the frequency being within a second range that is higher than the first range.

20. The method of claim 17, including:

determining a desired charging voltage in response to the power source type and the battery voltage, wherein the charging voltage is defined to effect a variable charging rate that varies depending on a frequency of current from the power source at a given battery voltage, and is defined to effect a constant charging rate in response to the power source being an AC power source having a constant output voltage.