Comparator Threshold Circuit for Anticipating Variable Pulse Widths
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Solution Overview
Problem
Existing circuits fail to accurately track and anticipate varying voltage pulse widths over time, leading to inconsistencies in pulse-width modulation, particularly in AC PWM systems.
Innovation Solution
An electrical circuit with a comparator and a controller that includes a storage element and a switch, which adjusts the threshold based on input pulse widths, allowing the output pulse width to track and anticipate the input pulse width by charging or discharging the storage element, and using a voltage divider to set the threshold based on the stored charge.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a simple switch and resistor circuit is used to generate pulse trains, then the circuit complexity is low, but the pulse width tracking precision deteriorates over time
Solution Approach 1:
The circuit anticipates the low-going end of input pulses by a predetermined time amount, proactively adjusting the output pulse width before the actual pulse ends. This preliminary action compensates for tracking delays and maintains precision without requiring complex real-time measurement systems.
Solution Approach 2:
The circuit uses feedback mechanisms where the output pulse width is continuously adjusted based on the detected input pulse characteristics. The controller monitors the input pulses and modifies the threshold component's reference voltage to maintain accurate tracking, creating a closed-loop system that corrects deviations over time.
2Measurement precision
If the threshold component continuously adjusts to track input pulse widths, then the pulse width tracking precision improves, but the response time to detect and measure deteriorates
Solution Approach 1:
By anticipating pulse transitions a predetermined time in advance, the circuit prepares the output threshold before the actual pulse event occurs. This eliminates the need for rapid real-time detection and measurement, as the system has already positioned itself to respond correctly.
Solution Approach 2:
The threshold component dynamically adjusts its reference voltage based on the input pulse characteristics. The controller modifies the threshold level in response to detected pulse widths, allowing the system to adapt its measurement criteria rather than requiring fixed-speed detection circuitry.
3Stability of the object's composition
If the circuit anticipates pulse width changes by a large time amount, then the pulse width consistency improves, but the loss of time increases
Solution Approach 1:
The circuit adjusts the anticipation time parameter based on the specific application requirements and input pulse characteristics. By optimizing this time parameter, the system achieves the minimum necessary anticipation to maintain pulse width consistency while minimizing the time penalty. The predetermined time amount can be tuned to balance consistency and response speed.
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
The circuit effectively tracks and anticipates input pulse widths with minimal delay, maintaining consistent pulse widths across cycles, even with varying input pulse widths, and can be modified to anticipate the next pulse width by adding additional comparators, ensuring reliable operation in AC PWM systems.
Implementation Method 1
a storage element arranged to store charge upon which the threshold is based
Implementation Method 2
at least one voltage divider coupled between a voltage source and the storage element, and arranged to set the threshold based on an amount of charge stored in the storage element
Data Source
AI summary
An electrical circuit and a procedure for tracking at least one input pulse width applied to the electrical circuit. The electrical circuit includes a threshold component (e.g., a comparator) arranged to provide an output pulse width based on whether an input to the threshold component exceeds a threshold. The circuit also includes a controller arranged to control the threshold of the threshold component, based on the at least one input pulse width applied to the electrical circuit, such that the output pulse width of the threshold component tracks the at least one input pulse width applied to the electrical circuit. The controller includes at least a switch, and the output pulse width tracks the at least one input pulse width by following or anticipating the pulse width. In one example embodiment the tracking is performed for a series of pulses of varied widths.