Electronic Safety Circuit for Overcurrent Protection
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Solution Overview
Problem
Conventional fine-wire fuses in electronic devices are inadequate for protecting against overcurrents and overvoltages due to slow response times and high resistance, leading to potential damage and compromised signal quality, especially in hi-fi devices.
Innovation Solution
Replacing the fine-wire fuse with a low-resistance metal pin and integrating an external electronic safety circuit that includes a current sensor, comparator, and bistable relay to accurately detect and interrupt overcurrents, thereby providing enhanced protection and minimizing signal interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a fine-wire fuse is used to protect electronic devices, then protection against overcurrent is provided, but the response time is slow and the switch-off characteristic has large uncertainty
Solution Approach 1:
The patent replaces the mechanical/thermal fine-wire fuse with an electronic protection circuit that uses electronic components (transistors, resistors, capacitors, operational amplifiers) to detect and respond to overcurrent conditions. This electronic system provides faster response time and more precise switch-off characteristics compared to the thermal-melting mechanism of traditional fuses.
Solution Approach 2:
The protection circuit continuously monitors the current flowing through the electronic device and provides feedback control. When overcurrent is detected, the circuit automatically triggers the protection mechanism to interrupt the power supply, ensuring reliable and timely protection without the uncertainty inherent in fuse melting characteristics.
2Reliability
If a fine-wire fuse is used, then protection function is provided, but the indifferent resistance is relatively high which impedes current flow
Solution Approach 1:
The patent replaces the passive fine-wire fuse with an active electronic protection circuit that has negligible resistance in the signal path. The circuit monitors current through sensing elements and controls power delivery electronically, eliminating the continuous resistance obstruction caused by fuse wires while maintaining protection functionality.
Solution Approach 2:
The protection circuit acts as an intelligent intermediary between the power source and the electronic device. It uses low-resistance current sensing elements to monitor flow and employs electronic switching mechanisms to control power delivery, thereby eliminating the harmful resistance effect of traditional fuses while preserving overcurrent protection.
3Reliability
If a fine-wire fuse with metal filament is used, then overcurrent protection is achieved, but considerable heat development occurs before tripping
Solution Approach 1:
The patent replaces the thermal-melting mechanism of metal filament fuses with an electronic detection and control system. The protection circuit uses electronic sensors and control elements to detect overcurrent conditions and interrupt power flow before excessive heat can develop, eliminating the thermal lag and heat generation problems of traditional fuses.
Solution Approach 2:
The protection circuit performs preliminary detection of current conditions continuously before dangerous heat levels can occur. By monitoring current flow and predicting potential overcurrent events, the system can trigger protection mechanisms in advance, preventing the considerable heat development that occurs in traditional fuses before they trip.
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 solution effectively prevents damage from overcurrents with precise switch-off characteristics and improves signal quality by reducing the volume resistance, ensuring better protection and performance in electronic devices.
Implementation Method 1
a current sensor (11) and at least one switching element (10), in particular a semiconductor switch or relay, are provided and are or can be coupled into the power supply path
Implementation Method 2
at least one switching element (10), in particular a semiconductor switch or relay, are provided and are or can be coupled into the power supply path to the electronic device
Data Source
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AI summary
The invention relates to a method for improved protection of an electronic device (2) against excessively high currents. It is applicable to electronic devices (2) that can be connected to a voltage source via an external power supply path (L) having at least one connecting cable and that have a replaceable miniature fuse inserted into a contact socket. This fuse is connected between the electronic device (2) and the power supply (L, N, S) supplying it in such a way that it is able to interrupt the current flow to the electronic device (2) in the event of a fault, particularly one characterized by an excessively high current. Miniature fuses are slow-blow and, moreover, have the disadvantage that, due to their relatively high resistance, they can negatively affect the signal quality of the supplied current.To avoid this disadvantage, according to the invention the miniature fuse is removed and an electrical bridge or disconnect with low electrical resistance is inserted into the contact instead of the miniature fuse, and the electronic device (2) is protected by an external or internal electronic safety circuit (1), wherein the electronic safety circuit (1) is arranged outside or inside the electronic device (2) of the power supply path (L).