Load-Isolated Leakage Current Measurement with a Holdup Capacitor
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Solution Overview
Problem
Current fault managed power systems require complex circuitry to detect leakage current in electronic circuits, increasing time and costs.
Innovation Solution
A fault managed power system with a source controller, pulsing controller, leakage current sensor, and load end circuit that uses pulsing inputs to measure leakage current by isolating the load during current-off intervals, allowing for accurate measurement without interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If complex circuitry is used to detect leakage current, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The patent applies periodic pulsing action to the power supply, creating alternating current-on and current-off intervals. During the current-off interval, the leakage current sensor can accurately measure leakage current without interference from the load, as the load is isolated during this period. This periodic action enables simple circuitry to achieve accurate measurement by exploiting the time separation between power delivery and measurement.
Solution Approach 2:
The patent segments the measurement process into distinct time intervals: current-on intervals for power delivery and current-off intervals for leakage current measurement. By segmenting the operational timeline, the system allows the leakage current sensor to measure accurately during off-intervals without requiring complex continuous measurement circuitry, thus reducing overall device complexity while maintaining measurement precision.
2Measurement precision
If complex circuitry is used to detect leakage current, then measurement precision is improved, but manufacturing cost increases
Solution Approach 1:
The patent uses periodic pulsing of the power supply to create measurement opportunities during current-off intervals. This approach allows the use of simple, cost-effective leakage current sensors that only need to operate briefly during off-intervals, rather than requiring expensive complex circuitry that would need to continuously and accurately measure leakage current throughout operation, thereby reducing manufacturing cost while maintaining measurement precision.
Solution Approach 2:
The patent implements preliminary isolation of the load during current-off intervals before leakage current measurement occurs. By pre-isolating the load through the blocking diode and holdup capacitor mechanism, the system prepares the circuit state to ensure accurate measurement without requiring complex continuous monitoring circuitry, thus reducing manufacturing cost while achieving precise leakage current detection.
3Productivity
If continuous power is supplied to the electronic circuit, then productivity is maintained, but leakage current measurement accuracy deteriorates
Solution Approach 1:
The patent implements periodic pulsing of the power supply, alternating between current-on intervals that maintain productivity and current-off intervals that enable accurate leakage current measurement. During current-off intervals, the leakage current sensor can accurately measure leakage current because the load is isolated. This periodic action allows the system to maintain continuous operational capability through on-intervals while achieving measurement accuracy during off-intervals, resolving the contradiction between productivity and measurement precision.
Solution Approach 2:
The patent segments the operational timeline into distinct current-on and current-off intervals. During current-on intervals, the system maintains full power delivery for productivity. During current-off intervals, the system performs leakage current measurement with the load isolated. This segmentation allows both high productivity during operation and accurate measurement during brief off-periods, eliminating the need to choose between continuous operation and measurement accuracy.
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
Enables efficient and accurate measurement of leakage current, reducing circuit complexity and costs while maintaining touch-safe operation.
Implementation Method 1
The holdup capacitor is configured to reverse bias the blocking diode during the current-off time interval to isolate the load from the electronic circuit
Implementation Method 2
The leakage current sensor is configured to measure leakage current in the electronic circuit during the current-off time interval
Data Source
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AI summary
A fault managed power system (FMPS) measures leakage current in an electronic circuit. The FMPS comprises a source controller, leakage current sensor, pulsing controller, and load end circuit. The source controller generates a pulsing input defining a current-on time interval and current-off time interval. During the current-off time interval, a source driver of the source controller opens a source switch to disconnect power from a power source. The leakage current sensor utilizes a leakage current sensor driver to open a leakage current sensor switch. The pulsing controller utilizes a pulsing driver to close a pulsing switch to provide a return path for leakage current during the current-off time interval. A holdup capacitor at the load end circuit reverse biases a blocking diode to isolate a load from the electronic circuit, such that leakage current flows in the leakage current sensor to enable an accurate measurement of the leakage current.