Valley-Fill Power Supply Circuit for Smaller AC Adapters
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The use of large electrolytic capacitors in power supply adapters for small electronic devices hinders the realization of compact and lightweight designs due to their significant volume, which is necessary for enhancing portability and meeting the power demands of modern electronic devices.
Innovation Solution
Implementing a rectifier circuit and a valley-fill circuit with energy storage capacitors that store and provide energy to increase the valley voltage of pulsating DC voltage, reducing the need for large electrolytic capacitors by utilizing capacitor valley filling technology.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If large capacity electrolytic capacitors are used for energy storage, then the output voltage stability is improved, but the volume of the power supply adapter increases
Solution Approach 1:
The patent divides the energy storage function into two distinct circuits: a PFC circuit with first energy storage capacitors for primary power factor correction and voltage stabilization, and a valley-fill circuit with second energy storage capacitors for supplementary voltage support during low-voltage periods. This segmentation allows each capacitor to be smaller than a single large capacitor would need to be, reducing overall volume while maintaining output stability.
Solution Approach 2:
The valley-fill circuit operates in advance by detecting when the rectified voltage enters a preset low-voltage range and proactively charging the second energy storage capacitors. When the voltage drops below the threshold, these pre-charged capacitors immediately discharge to fill the voltage valley, preventing output instability before it occurs. This preliminary action enables the use of smaller capacitors that don't need to handle the full energy storage burden alone.
2Use of energy by moving object
If large capacity electrolytic capacitors are used for energy storage, then the energy storage capacity is improved, but the weight of the power supply adapter increases
Solution Approach 1:
The total energy storage requirement is segmented between two capacitor groups in the PFC circuit and two capacitor groups in the valley-fill circuit. Each group handles a portion of the energy storage demand, allowing the use of smaller individual capacitors with lower weight compared to a single large-capacity electrolytic capacitor that would be needed to meet the same total energy storage requirement.
Solution Approach 2:
The second energy storage capacitors in the valley-fill circuit are charged in advance during normal voltage conditions and discharge only when needed during voltage valleys. This preliminary charging action means the capacitors don't need to continuously maintain high energy storage capacity, enabling the use of lighter-capacity components while still providing sufficient energy support during critical low-voltage periods.
3Reliability
If large capacity electrolytic capacitors are used for energy storage, then the voltage maintenance capability is improved, but the complexity of the circuit increases
Solution Approach 1:
The voltage maintenance function is segmented between the PFC circuit and the valley-fill circuit, with each having its own energy storage capacitors. The PFC circuit handles primary voltage stabilization through reactive power compensation, while the valley-fill circuit provides supplementary support during low-voltage periods. This functional segmentation distributes the voltage maintenance burden, allowing simpler control logic in each circuit compared to a single complex large-capacity capacitor system.
Solution Approach 2:
The control circuit detects when the rectified voltage enters the preset low-voltage range and proactively controls the switching element to charge the second energy storage capacitors. This preliminary action simplifies the control logic by using clear voltage threshold-based triggering rather than complex continuous regulation, reducing circuit complexity while maintaining effective voltage support capability.
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
Ensures stable output voltage while minimizing the size of the power supply adapter, optimizing energy storage capacity, and improving reliability through controlled discharge of energy storage capacitors.
Implementation Method 1
a valley-fill circuit, including at least one energy storage capacitor and being configured to: store energy through the at least one energy storage capacitor when the first pulsating DC voltage output by the rectifier circuit is in a first preset range, and provide energy through the at least one energy storage capacitor to increase a valley voltage
Data Source
AI summary
A power supply, a power supplying method, and a computer-readable storage medium are provided. The power supply includes a rectifier circuit and a valley-fill circuit. The rectifier circuit is used for voltage transformation of an input AC voltage to obtain a first pulsating DC voltage. The valley-fill circuit includes at least one energy storage capacitor and is used for storing energy through the at least one energy storage capacitor when the first pulsating DC voltage output by the rectifier circuit is in a first preset range and providing energy through the at least one energy storage capacitor when the first pulsating DC voltage output by the rectifier circuit is lower than a preset threshold, thereby to increase the valley voltage of the first pulsating DC voltage.