Differential Pressure Measurement with Dual A/D Sampling Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional differential pressure transmitting devices face instability in A/D conversion values due to fluctuations in power supply voltage when using a single A/D converting device for differential pressure, static pressure, and temperature sampling, especially when one device operates continuously and the other intermittently.
Innovation Solution
Both A/D converting devices are maintained in a constantly operating state to ensure a constant total current consumption, stabilizing the power supply voltage and reducing fluctuations in A/D conversion values, allowing for precise and stable differential pressure measurements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single A/D converting device is used to convert differential pressure, static pressure, and temperature into digital signals, then device complexity is reduced, but measurement precision deteriorates because the sampling period for differential pressure cannot be sufficiently shortened
Solution Approach 1:
The patent divides the A/D conversion function into two separate devices: a first A/D converting device dedicated to differential pressure signals and a second A/D converting device for static pressure and temperature signals. This segmentation allows the first device to operate continuously with short sampling periods, thereby improving differential pressure measurement precision while the second device handles environmental parameters with longer sampling periods.
2Measurement precision
If two A/D converting devices are provided with one for differential pressure and another for static pressure and temperature, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The second A/D converting device serves multiple functions by converting both static pressure and temperature signals into digital signals. This multi-functionality approach justifies the addition of the second device, as it handles multiple measurement tasks simultaneously, reducing the overall system complexity compared to having separate dedicated converters for each parameter.
3Use of energy by moving object
If the second A/D converting device operates intermittently to reduce power consumption, then energy use is reduced, but power supply voltage stability deteriorates causing A/D conversion value fluctuations
Solution Approach 1:
The patent implements a feedback mechanism where the processing device monitors the operating states of both A/D converting devices and adjusts their operation to maintain constant total current consumption. When the second device would otherwise be idle, the control unit activates it to consume current, thereby stabilizing the power supply voltage and preventing fluctuations in the first device's conversion values, while still achieving energy savings through selective operation.
4Productivity
If the first A/D converting device operates constantly to achieve short sampling periods, then productivity is improved, but power consumption increases
Solution Approach 1:
While the first A/D converting device operates continuously to maintain high sampling rates for differential pressure measurements, the system employs periodic action through the second device that operates intermittently based on sampling period requirements. The control unit orchestrates periodic activation of the second device to maintain power supply stability, allowing the first device to consume power continuously only when necessary for high-precision differential pressure monitoring.
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 ensures stable A/D conversion values from both devices, enabling precise and accurate differential pressure measurements by maintaining a constant power supply voltage, thus correcting for environmental changes affecting the sensed pressure differential.
Implementation Method 1
a first A/D converting device, which receives the supply of a power supply voltage and is in a constantly operating state, for converting an inputted analog signal into a digital signal
Implementation Method 2
a second A/D converting device, which receives a common power supply voltage, with the power supply voltage to the first A/D converting device being the common power supply voltage, to be in a constantly operating state, for converting an inputted analog signal into a digital signal
Implementation Method 3
a processing device for sampling, with a first period, an A/D converted value that has been converted into a digital signal by the first A/D converting device, and for sampling, with a second period that is longer than the first period, an A/D conversion value that has been converted into a digital signal in the second A/D converting device
Data Source
AI summary
One A/D converter and the other A/D converter have a common power supply voltage and sample an A/D conversion value at short time intervals and at a long time intervals, respectively. Both the A/D converter and the A/D converter are set in a constant active state (continuous conversion mode). This allows the total consumption current combining the consumption current of the A/D converter and the consumption current of the A/D converter to be constant, so that the power supply voltage is stabilized and a stable A/D conversion value can be obtained from each of the A/D converters.