Power Supply Control Apparatus Dynamic Current Threshold
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Solution Overview
Problem
Existing power supply control apparatuses struggle to prevent performance deterioration of wires due to overcurrent while allowing inrush currents to flow immediately after a switch is turned ON, as the current threshold value needs to be set higher than inrush current values to prevent wire damage, but this can lead to premature switching OFF when the wire temperature increases.
Innovation Solution
A power supply control apparatus with a switching circuit, current output circuit, resistance circuit, and voltage applying circuit that includes a series circuit of a second resistor and capacitor connected in parallel to the first resistor, allowing the current threshold value to adjust based on the power stored in the capacitor, enabling the inrush current to flow initially and then reducing the threshold to prevent overcurrent damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the current threshold value is set higher than or equal to the inrush current value to allow inrush current flow, then the load can operate normally, but the wire performance may significantly deteriorate after the wire temperature exceeds a certain threshold
Solution Approach 1:
The patent applies dynamics by making the current threshold value changeable over time. The control unit sets the current threshold value to a first value (higher than inrush current) immediately after switch ON to allow inrush current, then switches to a second value (lower than inrush current) after a predetermined time to prevent overcurrent damage. This dynamic adjustment resolves the contradiction between allowing load operation and protecting wire performance.
Solution Approach 2:
The patent applies preliminary action by pre-setting the current threshold value to a higher level before the inrush current occurs (immediately after switch ON). This allows the inrush current to pass through without triggering the protection mechanism, and then the threshold is lowered in advance to prevent future overcurrent damage, thus protecting the wire before damage can occur.
2Reliability
If the current threshold value is set to a value smaller than or equal to the inrush current value to prevent overcurrent damage, then wire performance is protected, but the switch turns OFF immediately after turning ON and the load cannot operate
Solution Approach 1:
The control unit dynamically adjusts the current threshold value based on the operating state. Immediately after switch ON, the threshold is set to a first value that allows inrush current passage, enabling load operation. After a predetermined time period, the threshold transitions to a second value that prevents overcurrent, thus protecting wire performance. This dynamic behavior resolves the contradiction.
Solution Approach 2:
The patent applies periodic action by dividing the protection period into two distinct time phases: an initial period immediately after switch ON where the higher threshold applies, and a subsequent period where the lower threshold applies. This time-based periodic control allows the system to accommodate inrush current initially, then enforce stricter protection later, resolving the contradiction between load operation and wire protection.
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 apparatus effectively allows inrush currents to flow without immediately switching OFF, thereby preventing significant wire performance deterioration by dynamically adjusting the current threshold value based on the capacitor's power storage, ensuring reliable operation and preventing overcurrent damage.
Implementation Method 1
a series circuit of a second resistor and a capacitor that is connected in parallel to the first resistor
Implementation Method 2
a resistance circuit through which the current that the current output circuit outputs flows, wherein the resistance circuit includes: a first resistor
Data Source
AI summary
A power supply control apparatus that includes a switching circuit that turns ON or OFF a switch provided at a point along a wire, wherein power supply via the wire is controlled by switching with the switching circuit; a current output circuit configured to output a current whose current value increases as a current value of a current flowing through the wire increases; a resistance circuit through which the current that the current output circuit outputs flows, wherein the resistance circuit includes: a first resistor; and a series circuit of a second resistor and a capacitor that is connected in parallel to the first resistor; and a voltage applying circuit configured to, if an end-to-end voltage value across the resistance circuit becomes higher than or equal to a predetermined voltage value, apply a voltage whose value is higher than the predetermined voltage value.