Power Control Circuit Burst Mode Noise Reduction
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Solution Overview
Problem
Switching mode power supplies under light load or no load conditions experience inefficiencies due to high power consumption and audible noise issues in burst mode operation.
Innovation Solution
A power control circuit comprising a clock generator, phase controller, and power limiter that generates a burst signal with a period not smaller than a group reference signal, switching the power supply between switching and non-switching states, and limits power output during burst up duration to reduce noise and conserve power.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If burst mode operation is used under light load or no load conditions, then power consumption is reduced, but audible noise is generated
Solution Approach 1:
The patent applies periodic action by implementing burst mode operation where the power supply switches between active switching cycles and non-switching periods. The clock generator produces clock signals that define switching cycles, and the burst mode controller periodically enables or disables these cycles based on load conditions. This periodic on-off pattern reduces average power consumption while maintaining the ability to deliver power when needed, directly addressing the contradiction between energy efficiency and noise generation by controlling the duty cycle of operation
Solution Approach 2:
The patent employs parameter changes by dynamically adjusting the burst ratio (the proportion of time spent in switching state versus non-switching state) based on load conditions. The controller modifies switching frequency, on-time duration, and burst period parameters to optimize performance. Under light load conditions, the system changes parameters to extend non-switching periods and reduce switching frequency, thereby lowering power consumption while managing audible noise through controlled parameter variation
2Loss of energy
If consecutive switching cycles are stopped in burst mode, then power conversion efficiency is improved, but audible noise occurs due to periodic switching patterns
Solution Approach 1:
The patent applies dynamics by making the switching behavior adaptive rather than fixed. The burst mode controller dynamically adjusts the switching parameters including burst period, on-time, and off-time based on real-time load conditions and feedback. This dynamic adjustment allows the system to optimize power conversion efficiency by stopping ineffective switching cycles while simultaneously managing audible noise by varying the timing and duration of switching bursts, preventing the system from operating at fixed frequencies that could generate annoying noise
Solution Approach 2:
The patent implements feedback mechanisms where the controller monitors load conditions, output voltage, and current to dynamically adjust burst mode operation. The feedback loop detects when the power supply enters light load or no load conditions and triggers appropriate burst mode behavior. This feedback control ensures that switching cycles are stopped or reduced only when necessary for efficiency, while preventing audible noise by maintaining appropriate switching activity levels based on actual system state and requirements
Data Source
AI summary
Power control circuits and methods are disclosed, suitable for a power supplier. A power control circuit has a clock generator, a phase controller and a power limiter. The clock generator provides a clock signal, substantially determining switching cycles of a power supply. The phase controller outputs a burst signal based on a group reference signal and a burst initiation signal, and makes a burst period corresponding to a burst signal not less than a group reference period corresponding to the group reference signal. The burst signal is capable of switching the power supplier between a switching state and a non-switching state. The power limiter limits the power transferred by the power supply in every switching cycle, during a burst-up duration after the power supply is switched from the non-switching state to the switching state. The burst initiation signal correlates to an output voltage of the power supplier.