Resettable Electronic Fuse Circuit for High-Current Device Protection
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Solution Overview
Problem
Conventional fuses in high-power devices, such as battery packs and chargers, become permanently inoperable when opened due to high currents, requiring repair and replacement, which is inefficient and costly.
Innovation Solution
Implementing a resettable electronic fuse that can selectively interrupt current based on detected conditions and reset itself or be controlled externally, replacing conventional fuses to provide a smaller footprint, lower heat generation, and reduced heat sinking requirements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional fuse is used to protect high-power devices from high currents, then device protection is achieved, but the device becomes permanently inoperable when the fuse opens
Solution Approach 1:
The fuse element transitions from a static conventional design to a dynamic resettable system. The heating element can change state between conductive and non-conductive, and the system can dynamically reset after tripping, allowing the device to recover operation automatically or through external control.
Solution Approach 2:
The system changes the electrical resistance parameter of the fuse element dynamically. When excessive current is detected, the heating element's resistance increases to interrupt current flow. After resetting, the resistance returns to normal, restoring full functionality without permanent damage.
2Reliability
If multiple components (conventional fuse and semiconductor switches) are used in the current path, then device protection is achieved, but heat generation and heat sinking requirements increase
Solution Approach 1:
The patent combines the fuse protection function and semiconductor switch functions into a single integrated resettable electronic fuse component. This merging eliminates the need for separate conventional fuse and switch components, reducing the total number of heat-generating elements in the current path.
Solution Approach 2:
The invention extracts and eliminates the conventional fuse component from the system, replacing it with an electronic resettable fuse that uses active control rather than passive thermal melting. This removes a significant heat-generating component while maintaining protection functionality.
3Reliability
If a conventional fuse is used in high-power devices, then current protection is achieved, but the device requires repair and replacement when the fuse opens
Solution Approach 1:
The resettable electronic fuse provides self-service by automatically resetting after tripping on excessive current. The system can restore normal operation without external intervention or component replacement, eliminating the need for repair services and reducing maintenance costs.
4Reliability
If conventional fuses and semiconductor switches are used separately, then device protection is achieved, but the circuit footprint and component count increase
Solution Approach 1:
The patent merges multiple discrete components (conventional fuse, semiconductor switches, control circuitry) into a single integrated resettable electronic fuse module. This consolidation significantly reduces the circuit footprint by eliminating the need for separate mounting areas for each component.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The resettable electronic fuse maintains device functionality by allowing temporary disruption of high currents, reducing heat dissipation, and offering cost and space savings by eliminating the need for multiple components.
Implementation Method 1
a sensing circuit configured to sense a parameter of the device
Implementation Method 2
a comparing circuit configured to compare the parameter of the device to a first reference value for the parameter of the device
Implementation Method 3
a semiconductor switch including a conductive state and a nonconductive state
Implementation Method 4
a conventional fuse, in addition to any series-connected semiconductor switches, all generate heat when passing current
Data Source
AI summary
A resettable electronic fuse for a high-power device such as a power tool, a battery pack for the power tool, or a battery pack charger. The resettable electronic fuse is connected in a current path of the device and is operable or configured to selectively interrupt current through the resettable electronic fuse based on a detected condition of the device (e.g., a detected fault condition of the device). The resettable electronic fuse is also configured to be reset after a detected fault condition has ended. In some embodiments, the resettable electronic fuse is configured to reset itself. In other embodiments, the resettable electronic fuse is configured to receive a signal (e.g., from a device controller) to reset.