Floating Voltage Measurement Circuit Using Identical Ceramic Capacitors
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Solution Overview
Problem
Measuring floating high voltage sources is complex due to the risk of modifying the voltage value, which can harm the system, and existing sensing circuits are ineffective in accurately measuring such voltages without impacting their value.
Innovation Solution
A circuit utilizing identical ceramic capacitors in two branches, with a control mechanism to adjust the voltage across one branch until the currents through two nodes are equal, allowing for precise measurement of the floating voltage without altering its value, using a comparison circuit and operational amplifier to generate and modify the voltage accordingly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a measuring circuit is used to measure floating voltage, then voltage measurement is achieved, but the measuring circuit modifies the voltage value and can harm the system
Solution Approach 1:
The patent introduces an intermediary measuring circuit that couples to the floating voltage source through a voltage divider network. This intermediary approach allows the measurement to be performed without direct connection to the floating voltage nodes, thereby avoiding modification of the voltage value while still enabling accurate measurement through the divided voltage components.
Solution Approach 2:
The patent creates a copy of the floating voltage measurement scenario by using identical voltage divider networks on both the floating voltage source and the reference voltage source. This copying approach allows the measuring circuit to compare voltage levels without directly tapping into or modifying the original floating voltage, thus maintaining measurement accuracy while avoiding harmful voltage modification.
2Measurement precision
If existing sensing circuits are used to measure floating voltage, then measurement capability is provided, but the circuits are ineffective in accurately measuring without impacting voltage value
Solution Approach 1:
The patent establishes equipotentiality by using identical voltage divider networks with the same component values for both the floating voltage source and the reference voltage source. This ensures that both voltage sources are treated equally in the measurement process, allowing accurate measurement of the floating voltage without introducing bias or modification, thereby improving both measurement precision and reliability.
Solution Approach 2:
The patent implements feedback by continuously monitoring the voltage levels and adjusting the reference voltage source to match the floating voltage source. This feedback mechanism ensures that the measuring circuit maintains accurate measurement conditions without impacting the floating voltage value, as the reference is dynamically adjusted to compensate for any potential modifications.
3Productivity
If continuous DC voltage is applied in the measurement process, then measurement can be performed, but it can harm the functionality of the system
Solution Approach 1:
The patent employs periodic action by using alternating voltage sources instead of continuous DC voltage for the measurement process. The voltage sources are switched alternately between the floating voltage source and the reference voltage source, allowing measurement to be performed without applying continuous DC voltage that could harm system functionality. This periodic switching enables measurement capability while avoiding harmful continuous voltage application.
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 accurate and non-intrusive measurement of floating high voltage sources, ensuring the measured voltage remains unaffected by the measurement process, with galvanic isolation and precise determination of voltage values.
Implementation Method 1
a first branch coupled between a first node and a second node, the first branch comprising a first ceramic capacitor, the first voltage being applied across the terminals of the first ceramic capacitor; and a second branch coupled between the first node and a third node, the second branch comprising a second ceramic capacitor, identical to the first ceramic capacitor
Data Source
AI summary
In an embodiment, a circuit includes a first branch coupled between a first node and a second node, the first branch including a first ceramic capacitor, the first ceramic capacitor including terminals configured to receive a first voltage applied therebetween. The circuit further includes a second branch coupled between the first node and a third node, the second branch including a second ceramic capacitor that is substantially identical to the first ceramic capacitor, the second ceramic capacitor including terminals configured to receive a second voltage applied therebetween. The circuit further includes a control circuit configured to modify the second voltage until a first current passing through the second node is substantially equal to a second current passing through the third node.