Temperature-Compensated Voltage Divider Circuit
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Solution Overview
Problem
Existing voltage measurement techniques face inaccuracies due to temperature variations, especially when measuring large voltages, as resistance values change with temperature, leading to measurement errors and requiring complex temperature compensation methods that are either impractical or inefficient.
Innovation Solution
A voltage divider circuit with a large resistor network and a small resistor network, where the resistors are selected such that their transfer ratios remain constant across temperature changes, allowing for continuous real-time compensation and enabling accurate measurement of large voltages without direct measurement, using a reference voltage and calculating the unknown voltage from a smaller divided voltage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a voltage divider circuit with resistors is used to measure large voltages, then the voltage can be reduced to a measurable level, but measurement errors occur due to temperature-induced resistance changes
Solution Approach 1:
The patent changes the parameters of the resistor network by selecting resistors with specific temperature coefficients and ratios. The key insight is to choose resistors where the temperature-induced resistance changes maintain a constant transfer ratio. This is achieved by selecting resistors with appropriate temperature coefficients (α1 and α2) and resistance values (R1 and R2) such that the ratio Uout/Uin remains constant across temperature variations, thereby compensating for temperature effects without requiring active temperature control.
2Reliability
If active temperature compensation methods (heating/cooling devices) are used, then the temperature can be controlled to a steady state, but the system becomes complex and requires additional power supply
Solution Approach 1:
The patent implements self-service temperature compensation through the inherent properties of the resistor network. By carefully selecting resistors with specific temperature coefficients and ratios, the circuit automatically compensates for temperature changes without requiring external control systems. The resistor network itself provides the compensation mechanism, eliminating the need for heating/cooling devices, temperature sensors, and control electronics, thereby reducing device complexity and power requirements while maintaining measurement reliability.
3Measurement precision
If the transfer ratio of the voltage divider is made temperature-independent, then measurement accuracy is maintained, but resistor selection becomes more restrictive
Solution Approach 1:
The patent addresses the manufacturing challenge by providing specific guidance on parameter selection. The solution involves choosing resistors with temperature coefficients that satisfy the relationship α1*R1 = α2*R2, and selecting resistance ratios that maintain the desired transfer ratio. The patent provides concrete examples and calculation methods to simplify the selection process, making it easier to manufacture temperature-compensated voltage dividers while maintaining measurement precision.
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
This approach allows for accurate determination of large voltages across varying temperatures without additional power supply, providing fast and stable measurements with operational freedom, as the resistor networks behave similarly under temperature changes, ensuring consistent transfer ratios and quick calculation speeds.
Implementation Method 1
a voltage divider circuit with a large resistor network and a small resistor network, where the resistors are selected such that their transfer ratios remain constant across temperature changes
Data Source
Figure 1
AI summary
The present invention discloses a manner of determining a high voltage value without actually measuring it directly, in varying possible temperatures. The present invention comprises two voltage divider circuits (108, 110; 109, 111), where the other one (i.e. a reference circuit 109, 111) is provided with a smaller reference input voltage (102). The transfer ratio can be obtained from the reference circuit (109, 111) through voltage measurements, and deduced into a transfer ratio of another circuit (108, 110), no matter of the ambient temperature value. When measuring a divided voltage value (103) of another circuit (108, 110), the desired high voltage value (101) can be calculated, no matter what the ambient temperature is.