Voltage Converter Off-Time Controller Dynamic Load Adjustment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing unregulated voltage converters face performance limitations due to fixed OFF time settings, leading to increased conduction losses and decreased output voltage, as they attempt to prevent current overshoot by extending OFF time across all load ranges, which is costly and inefficient.
Innovation Solution
A voltage converter with an OFF time controller that adjusts the OFF time based on load current, using either a gradually varying or stepped approach, to optimize OFF time between light and heavy loading conditions, ensuring efficient operation and preventing self-oscillation by controlling the duty cycle clocks and delay periods.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a fixed predetermined OFF time is used to prevent current overshoot, then reliability is improved, but conduction losses increase and output voltage decreases
Solution Approach 1:
The patent implements dynamic OFF time adjustment by sensing the load current and automatically modifying the OFF time period accordingly. During heavy load conditions, a longer OFF time is maintained to prevent overshoot, while during light load conditions, the OFF time is reduced to minimize conduction losses. This dynamic adaptation resolves the contradiction by making the system flexible rather than fixed.
Solution Approach 2:
The patent changes the temporal parameter (OFF time duration) based on operating conditions. By using a control circuit that monitors load current and adjusts the OFF time period, the system optimizes the balance between reliability protection and energy efficiency across different operating points.
2Reliability
If a fixed predetermined OFF time is used to prevent current overshoot, then reliability is improved, but productivity decreases due to reduced effective duty cycle
Solution Approach 1:
The system dynamically adjusts the OFF time based on instantaneous load conditions, allowing the effective duty cycle to be maximized during light load operations while maintaining adequate protection during heavy load operations. This resolves the contradiction between reliability and productivity by adapting the timing parameters to actual operating needs.
3Reliability
If additional snubber circuit protection is used to reduce overshoot impact, then reliability is improved, but device complexity and cost increase
Solution Approach 1:
The patent extracts the overshoot protection function from traditional passive snubber circuits and implements it through active control of the switching timing. By using a control circuit that senses load current and adjusts OFF time, the system achieves protection without requiring additional snubber components, thereby reducing device complexity and cost.
Solution Approach 2:
The patent employs feedback control by sensing the load current and using this information to adjust the OFF time period. This feedback mechanism provides active overshoot protection through timing control rather than passive energy dissipation circuits, eliminating the need for complex snubber networks.
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 solution enhances the efficiency and reliability of secondary side rectifiers by optimizing OFF time operation across an extended current range, preventing cross-conduction and allowing faster switching, thereby improving overall converter performance and reducing losses.
Implementation Method 1
a transformer with a first winding and a second winding
Data Source
AI summary
Various embodiments of the present invention provide voltage converters and methods for using such. As one example, a voltage converter is disclosed that includes a transformer with a first winding and a second winding. A voltage is applied to the first winding for a period that is followed by an OFF time. The voltage converter further includes an OFF time controller that is operable to adjust the OFF time based at least in part on a load current traversing the second winding.