Short Circuit Protection Apparatus with Variable Resistor Control
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Solution Overview
Problem
Existing relay testing apparatuses fail to prevent short circuits between the relay and external apparatuses, leading to discharge of the power supply and inability to diagnose the relay effectively, especially in cases of over-current conditions.
Innovation Solution
An apparatus with an input/output terminal unit connected via a second external power line to an external apparatus, featuring a switching unit, a variable resistor unit, and a control unit that determines short circuits by measuring current and adjusts the resistance value to prevent high currents and maintain the output within limits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a relay testing apparatus is used to diagnose relays, then relay diagnosis capability is improved, but the system becomes vulnerable to short circuits causing power supply discharge
Solution Approach 1:
A current limiting unit is introduced as an intermediary component between the power supply and the relay under test. This unit actively monitors current flow and inserts resistance when short circuits are detected, preventing direct short circuit paths while maintaining normal testing operations. The intermediary component resolves the contradiction by allowing diagnosis functionality while blocking harmful short circuit effects.
Solution Approach 2:
The system performs preliminary detection of short circuit conditions before they can cause damage. The current limiting unit continuously monitors current flow and proactively responds by increasing resistance when abnormal current patterns are detected, preventing the short circuit from developing into a damaging condition rather than reacting after damage occurs.
2Measurement precision
If the system allows high current flow for testing, then testing accuracy is improved, but short circuit risks increase causing power supply discharge
Solution Approach 1:
The current limiting unit dynamically adjusts its resistance based on real-time current measurements. During normal testing, it maintains low resistance to allow accurate measurements. When short circuit conditions are detected through current threshold monitoring, it rapidly increases resistance to limit current and protect the power supply. This dynamic adaptation resolves the contradiction between allowing sufficient current for accurate testing and preventing excessive current that causes discharge.
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
Effectively blocks short circuits by adjusting the resistance value of the variable resistor unit, preventing high currents and ensuring the driving voltage supply does not exceed its output limit, thereby enabling reliable relay diagnosis and preventing potential explosions.
Implementation Method 1
a variable resistor unit configured to be mounted on the internal power line and configured to be electrically connected to the other end of the switching unit
Implementation Method 2
a control unit configured to determine whether the input/output terminal unit is shorted based on a measurement current value of a current flowing through the internal power line
Data Source
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AI summary
Provided is an apparatus for preventing short circuit including an input/output terminal unit electrically connected, via a second external power line, to an external apparatus that is electrically connected to one of a driving voltage supply and a ground via a first external power line; an internal power line electrically connecting one of the driving voltage supply and the ground to the input/output terminal unit; a switching unit mounted on the internal power line, the switching unit having one end electrically connected to the input/output terminal unit and configured to energize or block the internal power line; a variable resistor unit mounted on the internal power line and electrically connected to the other end of the switching unit; and a control unit configured to determine whether the input/output terminal unit is shorted based on a measurement current value of a current flowing through the internal power line and control a set resistance value of the variable resistor unit in accordance with a result of determining whether the input/output terminal unit is shorted.