Voltage Probe Automatic DC Offset Compensation Circuit
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Solution Overview
Problem
Existing voltage rail probes require manual adjustment to offset DC voltage, which is time-consuming and inefficient, especially when the average voltage drifts over time, limiting the ability to accurately measure high frequency signals simultaneously.
Innovation Solution
A voltage probe with an integrator and amplifier configuration that automatically offsets DC voltage, using a capacitor and resistive divider to servo the output voltage to zero, while providing a monitor output to indicate the offset, allowing for simultaneous measurement of average DC and high frequency components without manual intervention.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If manual adjustment is used to offset DC voltage, then the measurement setup is simple, but the measurement process is time-consuming and inefficient
Solution Approach 1:
The voltage probe performs automatic DC offset measurement and indication without requiring manual adjustment by the user. The integrator circuit automatically integrates the output signal to determine the DC component, and the system self-adjusts to provide both AC measurement and DC offset indication simultaneously, eliminating the need for manual intervention.
Solution Approach 2:
The integrator circuit continuously monitors the output signal and automatically adjusts the DC offset compensation based on the integrated value. This feedback mechanism ensures that the DC component is accurately measured and compensated in real-time, improving measurement efficiency while maintaining signal integrity.
2Measurement precision
If DC offset is not compensated, then the circuit is simple, but the dynamic range for measuring high frequency signals is reduced
Solution Approach 1:
The measurement function is segmented into two independent paths: one for AC component measurement through the capacitor-coupled output, and another for DC offset measurement through the integrator circuit. This segmentation allows both AC and DC measurements to occur simultaneously without interfering with each other, improving measurement precision while keeping the circuit design modular and manageable.
Solution Approach 2:
The integrator circuit acts as an intermediary that separates the DC component from the AC signal. By integrating the output signal, it extracts the DC offset information without affecting the AC measurement path, enabling accurate high-frequency signal measurement while maintaining a relatively simple circuit configuration.
3Extent of automation
If automatic DC offset measurement is implemented, then measurement efficiency improves, but the device complexity increases
Solution Approach 1:
The integrator circuit serves multiple functions: it measures the DC offset component, provides automatic compensation control, and generates the indication signal for DC voltage. This multi-functionality reduces the need for separate dedicated circuits for each function, thereby improving automation while limiting the increase in overall device complexity.
Data Source
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AI summary
A voltage probe comprising: an input connector; an output connector; and an offset measurement connector. The voltage probe also includes an integrator, and amplifier and a capacitor. The capacitor has a first plate connected to the input connector; and a second plate connected to the output connector. The integrator input terminal is connected to the output connector. The integrator output terminal is connected to both: i) the amplifier second input terminal; and ii) the offset measurement connector. The amplifier first input terminal is connected to the input connector. The amplifier output terminal is connected to the second plate of the capacitor. Such a voltage probe can automatically offset a DC voltage that is measured from a voltage rail while simultaneously indicating the amount of offset. Therefore, a measurement of average DC and maximum gain of high frequency components of the voltage on the voltage rail can be measured at the same time.