Switching Converter Dummy Load Control for Non-Audible Operation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Switching converters generate audible noise under light or no load conditions due to a decrease in switching frequency into the audible range.
Innovation Solution
A control circuit is introduced in the switching converter that includes a switch control circuit and a dummy load control circuit to regulate the power consumed by a dummy load, preventing the switching frequency from entering the audible range by controlling the dummy load based on feedback voltage signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the switching frequency is decreased to reduce power loss under light load conditions, then energy efficiency is improved, but audible noise is generated due to the frequency entering the audible range
Solution Approach 1:
A dummy load is introduced as an intermediary element to absorb excess energy and maintain the switching frequency above the audible range. The dummy load control circuit regulates the switching converter's operation by providing a controlled load, preventing the frequency from dropping into the audible range while minimizing power loss through intelligent control.
Solution Approach 2:
The system dynamically changes the operating parameters by adjusting the dummy load resistance based on the switching frequency and load conditions. By varying the dummy load, the system maintains the switching frequency in the ultrasonic range even under light load conditions, thereby eliminating audible noise while preserving energy efficiency.
2Object-generated harmful factors
If a dummy load is added to maintain switching frequency above audible range, then audible noise is prevented, but device complexity increases
Solution Approach 1:
The dummy load control circuit is designed to perform multiple functions: it maintains switching frequency above the audible range, regulates power consumption, and adapts to different load conditions. By integrating these functions into a single control mechanism, the system avoids the need for separate circuits for each function, thereby minimizing the increase in device complexity.
Solution Approach 2:
The dummy load control circuit automatically adjusts the dummy load resistance based on feedback from the switching frequency and load conditions. This self-regulating mechanism eliminates the need for complex external control systems, as the circuit itself manages the frequency regulation and noise prevention without additional complexity.
Data Source
AI summary
A control circuit used in a switching converter. The switching converter has a switching circuit and provides an output voltage at an output terminal. The control circuit includes a switch control circuit and a dummy load control circuit. The switch control circuit receives a feedback voltage signal indicative of the output voltage and generates a switch control signal to control a switch of the switching circuit based on the feedback voltage signal. The dummy load control circuit is coupled to the switch control circuit and generates a dummy load control signal to regulate the power consumed by a dummy load coupled between the output terminal and a reference ground based on the operation of the switch control circuit.