Burst-Mode Switching Control for Stable Light-Load Power Supply
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Switching power supply circuits face efficiency issues in light load conditions due to increased stop periods of switching operations, leading to a drop in power supply voltage and potential failure of control circuits.
Innovation Solution
A switching control circuit that determines whether to shift to burst mode based on load conditions, utilizing a clock circuit to measure stop periods and a control circuit to adjust these periods, ensuring stable operation and efficiency by decreasing stop times when necessary.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the stop period of switching operation is increased to increase efficiency in light load condition, then energy efficiency is improved, but the power supply voltage generated in the auxiliary coil drops and the control circuit may not normally operate
Solution Approach 1:
The patent applies dynamics by making the stop period adjustable rather than fixed. The control circuit dynamically changes the stop period based on the power supply voltage level. When the voltage drops below a threshold, the control circuit decreases the stop period to ensure sufficient energy is available for control circuit operation, thus maintaining reliability while still achieving efficiency improvements through burst mode operation.
Solution Approach 2:
The patent implements feedback by having the control circuit monitor the power supply voltage generated in the auxiliary coil and adjust the stop period accordingly. The control circuit detects when the voltage drops due to an extended stop period and responds by reducing the stop period duration, creating a closed-loop control system that balances efficiency and reliability.
2Use of energy by moving object
If the stop period is extended to improve efficiency, then power consumption is reduced, but the voltage from the auxiliary coil decreases affecting control circuit functionality
Solution Approach 1:
The control circuit dynamically adjusts the stop period based on real-time monitoring of the power supply voltage. When voltage levels indicate insufficient energy for proper control circuit operation, the system automatically reduces the stop period, ensuring the control circuit can continue to function while still maintaining improved efficiency through burst mode operation.
Solution Approach 2:
The system uses feedback from the power supply voltage level to control the stop period duration. The control circuit detects voltage drops and responds by adjusting the stop period to maintain adequate voltage levels for control circuit operation, creating a self-regulating mechanism that balances power consumption and operational functionality.
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 solution allows for increased efficiency in light load conditions while maintaining stable operation of the switching power supply circuit, preventing power supply voltage drops and ensuring continuous control circuit functionality.
Implementation Method 1
a voltage generated in an auxiliary coil is supplied, as a power supply voltage, to a control circuit
Implementation Method 2
a transformer including a primary coil, a secondary coil, and an auxiliary coil magnetically coupled to the primary coil or the secondary coil
Data Source
AI summary
A power supply circuit generating an output voltage at a target level and applying the output voltage to a load. The power supply circuit includes a transformer including a primary coil, a secondary coil and an auxiliary coil, a transistor coupled to the primary coil, and a switching control circuit configured to control switching of the transistor based on a voltage from the auxiliary coil. The switching control circuit includes a determination circuit configured to determine whether to shift to a burst mode operation based on whether the load is a light load, and a burst control circuit. The burst control circuit has a clock circuit configured to measure a stop period during which the switching of the transistor is stopped in the burst mode operation, and a control circuit configured to, upon detecting that the stop period is longer than a first time period, perform control to decrease the stop period.