Maximum power regulated battery charger
First Claim
1. An AC adapter having an output for providing DC power to a substantially constant power load which can be selectively enabled or disabled, having a maximum load value and being substantially constant above a lower voltage level and to charge a battery, where the load and the battery are each electrically coupled to the output, and the battery is removably connected to the circuit and has a fully charged voltage level, comprising:
- power regulated source means having an output power control input, an output power sense output and a voltage output having a positive terminal and a negative terminal, wherein the positive terminal of the battery and the load are connected to said positive terminal of said voltage output, the negative terminal of the load is connected to said negative terminal of said voltage output, and the negative terminal of the battery is coupled to said negative terminal of said voltage output, wherein said voltage output provides the AC adapter output, for providing up to a predetermined maximum power level to the substantially constant load and the battery, said power regulated source means predetermined maximum power level exceeding the maximum load provided by the substantially constant load, such that the battery absorbs the remaining power supplied by said power regulated source means and said predetermined maximum power level being less than the battery fully charged voltage level times the current drawn by the substantially constant power load at the lower voltage level; and
means having a sense input and a control output, said control output connected to said output power control input and said sense input connected to said output power sense output, for controlling the voltage output of said power regulated source means, said control means including means for limiting the output power provided by said power regulated source means to said predetermined maximum power level when the battery is in a condition for rapid charging and the total load presented to said power regulated source means by the battery and the substantially constant power load would otherwise cause the power output by said power regulated source means to exceed said predetermined maximum power level.
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Accused Products
Abstract
An AC adapter that allows a lower power rating while still providing the necessary power to a load which is substantially constant over a varying voltage range and to charge a discharged Ni-Cad battery in a desired time. The AC adapter regulates its output power to a maximum level just greater than the maximum of the load rather than providing a controlled current until a predetermined fully charged voltage is attained. In this manner, the output voltage and current are allowed to vary inversely with respect to each other in order to maintain the desired power level, allowing the output current level to be reduced as the voltage level increases. A regulated voltage mode is also provided to keep the output voltage from rising above a predetermined maximum level should the Ni-Cad battery be disconnected. One preferred embodiment includes a regulated current mode wherein the current through the Ni-Cad battery is maintained at the desired trickle level once the battery is fully charged.
129 Citations
30 Claims
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1. An AC adapter having an output for providing DC power to a substantially constant power load which can be selectively enabled or disabled, having a maximum load value and being substantially constant above a lower voltage level and to charge a battery, where the load and the battery are each electrically coupled to the output, and the battery is removably connected to the circuit and has a fully charged voltage level, comprising:
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power regulated source means having an output power control input, an output power sense output and a voltage output having a positive terminal and a negative terminal, wherein the positive terminal of the battery and the load are connected to said positive terminal of said voltage output, the negative terminal of the load is connected to said negative terminal of said voltage output, and the negative terminal of the battery is coupled to said negative terminal of said voltage output, wherein said voltage output provides the AC adapter output, for providing up to a predetermined maximum power level to the substantially constant load and the battery, said power regulated source means predetermined maximum power level exceeding the maximum load provided by the substantially constant load, such that the battery absorbs the remaining power supplied by said power regulated source means and said predetermined maximum power level being less than the battery fully charged voltage level times the current drawn by the substantially constant power load at the lower voltage level; and means having a sense input and a control output, said control output connected to said output power control input and said sense input connected to said output power sense output, for controlling the voltage output of said power regulated source means, said control means including means for limiting the output power provided by said power regulated source means to said predetermined maximum power level when the battery is in a condition for rapid charging and the total load presented to said power regulated source means by the battery and the substantially constant power load would otherwise cause the power output by said power regulated source means to exceed said predetermined maximum power level. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18)
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19. A method of providing power from a regulated power source to a substantially constant power load which can be selectively enabled or disabled, having a predetermined maximum load level and being substantially constant above a lower voltage level and to charge a removably connected battery having a fully charged voltage level, wherein the battery and the load are electrically coupled in parallel, comprising the steps of:
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impressing the output of the regulated power source across the battery and the load; sensing the output voltage of the regulated power source; controlling the regulated power source to provide up to a predetermined maximum power level, wherein said predetermined maximum power level exceeds the predetermined maximum load level of the substantially constant power load and said predetermined maximum power level is less than the battery fully charged voltage level times the current drawn by the substantially constant power load at the lower voltage level; and limiting the output power of the regulated power source to regulate the output voltage at a predetermined maximum voltage level when the total load presented by the load and the battery would otherwise cause the voltage provided by the regulated power source to exceed said predetermined maximum voltage level.
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20. A method of providing power from a regulated power source to a substantially constant power load which can be selectively enabled or disabled, having a predetermined maximum load level and being substantially constant above a lower voltage level and to charge a removably connected battery having a fully charged voltage level, wherein the battery and the load are electrically coupled in parallel, comprising the steps of:
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impressing the output of the regulated power source across the battery and the load; sensing the output voltage of the regulated power source; sensing the current through the battery; sensing the temperature of the battery; controlling the regulated power source to provide a predetermined maximum power level wherein said predetermined maximum power level exceeds the predetermined maximum load level of the substantially constant power load and said predetermined maximum power level is less than the battery fully charged voltage level times the current drawn by the substantially constant power load at the lower voltage level; limiting the output power of the regulated power source to regulate the output voltage at a predetermined maximum voltage level when the battery is not connected or when the battery is connected and the battery voltage is substantially equal to said predetermined maximum output voltage level; and limiting the output power of the regulated power source to regulate the current through the battery at a predetermined trickle level when the temperature of the battery is not within allowable limits or when the battery has been discharged and then charged such that the temperature of the battery exceeds a predetermined high temperature level.
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21. An AC adapter having an output for charging a Nickel-based battery electrically coupled to the output, comprising:
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means for monitoring the battery temperature; means for monitoring the battery current; means for monitoring the battery voltage; means coupled to said battery temperature, current and voltage monitoring means for determining whether the battery is in a condition for fast charging; and means coupled to said battery fast charging determining means and for coupling to the battery for providing a substantially constant predetermined power level sufficient to fast charge the battery when the battery is in a condition for fast charging and for providing a reduced amount of power when the battery is not in a condition for fast charging, wherein said power providing means includes; DC source voltage means having a positive terminal and a negative terminal; a transformer having a primary inductance including a first terminal and a second terminal and having a secondary inductance including a first terminal and a second terminal, where said first terminal of said primary inductance is coupled to said positive terminal of said DC source voltage means; a transistor having an input terminal, an output terminal and a control terminal, said input terminal coupled to said second terminal of said primary inductance of said transformer, said control terminal providing an output power control input; means coupled between said output terminal of said transistor and said negative terminal of said DC source voltage means for converting the level of current through said primary inductance of said transformer into a proportional voltage, said proportional voltage providing an output power sense output; means for generating an oscillating signal having a constant predetermined frequency; and activation means coupled to said oscillating signal means, said output power control input and said output power sense output, for providing a signal to said output power control input at the beginning of each cycle of said constant predetermined frequency, and for removing said signal to said output power control input if the level of said output power sense output reaches a predetermined maximum level. - View Dependent Claims (22, 23)
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24. An AC adapter having an output for providing DC power to a substantially constant power load which can be selectively enabled or disabled having a maximum load value and being substantially constant above a lower voltage level and to charge a battery, where the load and the battery are each electrically coupled to the output, and the battery is removably connected to the circuit and has a fully charged voltage level, comprising:
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means for providing an unregulated DC source voltage; a transformer having a primary and a secondary, wherein said primary is coupled to said unregulated DC source voltage means; an output rectifier and filter means coupled to said transformer secondary for implementing flyback operation, wherein said transformer stores energy when current flows through said transformer primary and transfers said stored energy to said transformer secondary when the current flow through said transformer primary is terminated; a transistor having a control terminal and a current path, wherein said current path is coupled in series with said DC source voltage means, said transformer primary and ground, wherein said current path allows current flow through said transformer primary from said unregulated DC source voltage means to ground when turned on, and substantially terminates the current flow through said transformer primary when turned off; means coupled in series with said transformer primary for sensing the level of current through said transformer primary; means for generating an oscillating signal having a constant predetermined frequency; pulse width modulation means coupled to said oscillating signal means, said primary current sensing means, said transistor control terminal and said oscillating signal means for turning said transistor on at the beginning of each cycle of said constant predetermined frequency and for turning said transistor off when the current reaches a predetermined maximum level wherein said predetermined maximum current level corresponds to a predetermined maximum output power level; and wherein said predetermined maximum output power level exceeds the maximum load provided by the substantially constant load, so that the battery absorbs the remaining power transferred by said transformer and wherein said predetermined maximum power level is less than the battery fully charged voltage level times the current drawn by the substantially constant power load at the lower voltage level. - View Dependent Claims (25, 26, 27, 28, 29, 30)
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Specification