Adjustable Input Capacitance for Low-Capacity Power Supply Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Low-capacity power supplies face instability due to fluctuations in AC voltage, which can affect the operation of image forming apparatuses by influencing the AC current and resulting in an unstable DC output.
Innovation Solution
The implementation of adjustable input capacitance in low-capacity power supplies, achieved by adding adjustment capacitors in series with existing capacitors and using switches to control their connection to the rectifier, allows for dynamic adjustment of capacitance to stabilize the output voltage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the capacitance of input capacitors is increased to reduce the influence of AC voltage fluctuations, then the stability of DC output is improved, but the power supply capacity increases and power consumption increases
Solution Approach 1:
The patent changes the electrical parameter (capacitance) of the input circuit based on AC voltage conditions. When AC voltage is normal, larger capacitance (C1+C2+C3+C4) is used to stabilize output. When AC voltage is low, smaller capacitance (C3+C4 only) is used to reduce power consumption, directly addressing the contradiction between stability and power consumption
2Power
If the capacitance of input capacitors is decreased to reduce power consumption, then the power supply capacity is reduced, but the stability of DC output deteriorates due to increased influence of AC voltage fluctuations
Solution Approach 1:
The power supply system performs self-service by automatically detecting AC voltage conditions and autonomously reconfiguring its own capacitor network through control switches. The system monitors its own operating conditions and adjusts its electrical characteristics without external intervention, optimizing both stability and power consumption based on real-time voltage conditions
Solution Approach 2:
The patent implements feedback by detecting AC voltage conditions and using this information to control the switches that reconfigure the capacitor network. The detection result feeds back to the control logic, which adjusts the capacitance configuration accordingly, creating a closed-loop system that maintains optimal performance under varying voltage conditions
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 approach effectively reduces the impact of AC voltage fluctuations on the power supply, ensuring a stable DC output and preventing operational stops of electronic components, even during reduced AC voltage conditions.
Implementation Method 1
a capacitor insulated low-capacity power supply configured to insulate an AC power supply side and a DC output side with a capacitor
Implementation Method 2
rectify and smooth an AC voltage applied to first and second capacitors
Implementation Method 3
rectify and smooth an AC voltage applied to first and second capacitors, to use the rectified and smoothed voltage as power supply
Data Source
AI summary
A low-capacity power supply is described in which an input capacitance may be adjusted. In one example, input capacitors may be located between an AC power supply and a rectifier. Additional adjustment capacitors may be located on one or more input lines to the rectifier. The adjustment capacitors may be added in series to at least one of the input capacitors to decrease the input capacitance of the rectifier. In this example, the power provided downstream of the rectifier may be adjusted to increased or reduced as needed. In other examples, additional switches are provided for the input capacitors to selectively add their capacitance to or remove their capacitance from the input of the rectifier.