Battery protection circuit
First Claim
1. A battery protection circuit, comprising:
- a. at least one rechargeable cell;
b. a safety circuit coupled to the at least one rechargeable cell, the safety circuit comprising a voltage monitoring circuit and a current monitoring circuit;
c. at least one disconnect element coupled serially with the at least one rechargeable cell;
d. a current monitoring circuit;
e. a circuit for simulating an overcurrent condition within the safety circuit when the current monitoring circuit determines that the current flowing to or from the at least one rechargeable cell exceeds a predetermined current threshold;
f. a transistor coupled serially with the at least one rechargeable cell; and
g. a resistor having an impedance less than 100 Ohms coupled in parallel with the transistor;
wherein when the current flowing to or from the at least one rechargeable cell exceeds the predetermined current threshold, the current monitoring circuit causes the transistor to enter a high-impedance state.
2 Assignments
0 Petitions
Accused Products
Abstract
A battery protection circuit is provided that includes current monitoring circuit. The current monitoring circuit senses current flowing to or from a rechargeable cell. When the current exceeds a maximum value, the current monitoring circuit actuates, whereby opening a transistor. The transistor has a resistor couple in parallel. When the transistor opens, current is forced through the resistor coupled in parallel with the transistor, thereby limiting the current to a maximum value. The current monitoring circuit also simulates an overcurrent condition in the safety circuit. The overcurrent condition causes a disconnect switch to open, thereby disconnecting the cell(s) from the external terminals.
18 Citations
15 Claims
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1. A battery protection circuit, comprising:
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a. at least one rechargeable cell;
b. a safety circuit coupled to the at least one rechargeable cell, the safety circuit comprising a voltage monitoring circuit and a current monitoring circuit;
c. at least one disconnect element coupled serially with the at least one rechargeable cell;
d. a current monitoring circuit;
e. a circuit for simulating an overcurrent condition within the safety circuit when the current monitoring circuit determines that the current flowing to or from the at least one rechargeable cell exceeds a predetermined current threshold;
f. a transistor coupled serially with the at least one rechargeable cell; and
g. a resistor having an impedance less than 100 Ohms coupled in parallel with the transistor;
wherein when the current flowing to or from the at least one rechargeable cell exceeds the predetermined current threshold, the current monitoring circuit causes the transistor to enter a high-impedance state. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A battery protection circuit having an current monitoring circuit, wherein the current monitoring circuit determines when a current exceeds a predetermined threshold, comprising:
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a. at least one rechargeable cell;
b. at least one safety circuit coupled to the at least one rechargeable cell;
c. at least one switch coupled serially with the at least one rechargeable cell;
d. at least one circuit for simulating an overcurrent condition within the safety circuit when the current monitoring circuit determines that the current exceeds the predetermined threshold;
e. a transistor coupled serially with the at least one rechargeable cell; and
f. a resistor having an impedance less than 100 Ohms coupled in parallel with the transistor;
wherein when the exceeds a predetermined current threshold, the current monitoring circuit causes the transistor to enter a high-impedance state. - View Dependent Claims (10, 11, 12, 13, 14, 15)
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Specification