Charging circuit with two levels of safety
First Claim
1. A battery charging circuit, comprising:
- a. input terminals for receiving an input voltage and an input current;
b. an overvoltage protection circuit;
c. a voltage regulation circuit having an output voltage;
d. a current regulation circuit;
e. a means for sensing current flowing through the charging circuit;
f. battery terminals for coupling to a rechargeable battery cell; and
g. a microprocessor having a plurality of inputs and outputs;
wherein a first input is coupled to one of the input terminals;
further wherein a second input is coupled to the voltage regulation circuit;
further wherein a third input is coupled to the battery terminals;
further wherein a fourth input is coupled to the means for sensing current;
further wherein the microprocessor is capable of actuating a voltage regulation circuit control signal to cause the voltage regulation circuit to enter a high impedance state; and
further wherein the microprocessor is capable of actuating a current regulation circuit control signal to cause the current regulation circuit to enter a high impedance state.
2 Assignments
0 Petitions
Accused Products
Abstract
A battery charging circuit having two levels of safety protection is provided. The circuit is said to have “two levels” of safety because if any one component fails (either as a short circuit or as an open circuit) the remainder of the charging circuit ensures that a rechargeable battery coupled to the circuit will not be overcharged. The circuit includes both hardware and firmware protection components, with a microprocessor providing the firmware protection. Overvoltage protection, voltage regulation and current regulation are provided, along with a microprocessor capable of sensing a plurality of voltages across the circuit. The overvoltage protection, voltage regulator and current regulator each include safety actuation points. In parallel, the microprocessor may isolate a rechargeable battery from the cell if voltage and current minimums and maximums are exceeded. The microprocessor further is able to isolate the battery from the circuit if the power dissipation in the voltage regulator, the current regulator or the overall charging circuit is exceeded, provided the microprocessor has decremented current to a minimum level.
31 Citations
20 Claims
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1. A battery charging circuit, comprising:
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a. input terminals for receiving an input voltage and an input current;
b. an overvoltage protection circuit;
c. a voltage regulation circuit having an output voltage;
d. a current regulation circuit;
e. a means for sensing current flowing through the charging circuit;
f. battery terminals for coupling to a rechargeable battery cell; and
g. a microprocessor having a plurality of inputs and outputs;
wherein a first input is coupled to one of the input terminals;
further wherein a second input is coupled to the voltage regulation circuit;
further wherein a third input is coupled to the battery terminals;
further wherein a fourth input is coupled to the means for sensing current;
further wherein the microprocessor is capable of actuating a voltage regulation circuit control signal to cause the voltage regulation circuit to enter a high impedance state; and
further wherein the microprocessor is capable of actuating a current regulation circuit control signal to cause the current regulation circuit to enter a high impedance state. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A battery charging circuit, comprising:
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a. input terminals for receiving an input voltage and an input current;
b. an overvoltage protection circuit;
c. a voltage regulation circuit having an output voltage;
d. a current regulation circuit;
e. a means for sensing current flowing through the charging circuit;
f. battery terminals for coupling to a rechargeable battery cell; and
g. a microprocessor having a plurality of inputs and outputs;
wherein by way of the plurality of inputs, the microprocessor is capable of sensing;
1. an input voltage across the input terminals;
2. the output voltage of the voltage regulation circuit;
3. a voltage across the voltage regulation circuit;
4. a voltage across the current regulation circuit;
5. a voltage across the means for sensing current; and
6. a voltage across the battery terminals. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20)
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Specification