Switching Power Supply Voltage Stability
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Solution Overview
Problem
Conventional switching power supply devices of the LLC type face challenges in maintaining stable output voltage when significant load fluctuations occur, particularly in projection video display devices with semiconductor laser diodes, as they have a limited output voltage control range and are not suitable for handling significant load changes.
Innovation Solution
The proposed solution involves a switching power supply device with a transformer having a primary and secondary winding divided into multiple units, a resonant capacitor, rectifier diodes, an output voltage switching circuit, a current detection circuit, and a controller that adjusts the output voltage based on current detection, allowing for stable power supply even during significant load fluctuations by switching between different output voltages.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional LLC type switching power supply device is used, then the circuit is simple and easy to manufacture, but the output voltage cannot be maintained when significant load fluctuations occur
Solution Approach 1:
The secondary winding is divided into multiple independent winding units, each with its own rectifier diode and voltage extraction circuit. This segmentation allows the output voltage switching circuit to selectively combine different winding unit outputs to maintain stable voltage despite load fluctuations, resolving the contradiction between reliability and complexity by distributing the voltage regulation function across multiple segments.
Solution Approach 2:
The output voltage switching circuit dynamically selects and switches between different voltage outputs from multiple rectifier diodes based on real-time load conditions. This dynamic adaptation enables the power supply to maintain stable output voltage under varying load conditions, achieving reliability improvement while the switching mechanism manages the added complexity through controlled adaptability.
2Adaptability or versatility
If the secondary winding is divided into multiple winding units with rectifier diodes, then the output voltage can be controlled under load fluctuations, but the device complexity increases
Solution Approach 1:
Multiple winding units are designed with identical structures (each containing a rectifier diode and voltage extraction circuit), creating universal modular components. This multi-functionality allows any winding unit to serve as a voltage source under different load conditions, achieving high adaptability to load fluctuations while managing complexity through standardized, interchangeable modules that simplify design and maintenance.
3Reliability
If an output voltage switching circuit is added to switch between multiple voltages, then the power supply stability under load changes improves, but the device complexity increases
Solution Approach 1:
The controller receives feedback about load conditions and automatically adjusts the output voltage switching circuit to select the appropriate voltage combination from multiple winding units. This feedback mechanism maintains power supply stability under varying load conditions while managing switching circuit complexity through automated control that eliminates the need for complex manual regulation mechanisms.
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 configuration enables the switching power supply device to maintain a predetermined output voltage and supply power stably even under significant load fluctuations, ensuring reliable operation of the projection video display device by adjusting the output voltage in response to detected current changes.
Implementation Method 1
a resonant capacitor which forms a resonant circuit including the primary winding as a component
Implementation Method 2
a transformer which includes a primary winding and a secondary winding divided into a plurality of winding units
Data Source
AI summary
A switching power supply device includes a transformer which includes a secondary winding divided into a plurality of winding units, a resonant capacitor, and a first switching element and a second switching element. Further, the switching power supply device includes a plurality of rectifier diodes which extracts voltages induced to the secondary winding in the winding units, an output voltage switching circuit which switches the voltages extracted from the plurality of rectifier diodes and outputs a switched voltage, a current detection circuit which detects a current flowing in a load circuit, and a controller which controls the output voltage switching circuit based on a detection result of the current detection circuit.