Single Diode Rectifier Input Circuit for Power Converter
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Solution Overview
Problem
Existing power converters are costly due to the use of full bridge rectifiers in their input sections, which can be replaced by a single diode without compromising performance for applications like battery chargers and standby power supplies.
Innovation Solution
A power converter design that replaces the full bridge rectifier with a single diode in the input section, utilizing a non-electrolytic capacitor and an inrush resistor, along with a coil, to filter distortions caused by the SMPS IC, and employs the Philips Semiconductors TEA1520P IC with a high gain feedback loop and internal start-up circuit for improved performance and reduced component count.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a full bridge rectifier is used in the input section, then reliable rectification is achieved, but device complexity and cost increase
Solution Approach 1:
The patent extracts and removes three diodes from the traditional full bridge rectifier configuration, reducing it to a single diode circuit. This simplification is made possible by the specific operational characteristics of the TEA1520P controller, which can tolerate the asymmetry introduced by the single diode while maintaining reliable rectification functionality.
Solution Approach 2:
The patent changes the operational parameters of the rectifier circuit by transitioning from a symmetric full-bridge configuration to an asymmetric single-diode configuration. This parameter change is compensated by adjusting the feedback loop characteristics of the TEA1520P controller, which has a high gain feedback loop that can accommodate the modified rectification waveform.
2Object-generated harmful factors
If a full bridge rectifier with multiple electrolytic capacitors is used, then adequate filtering is achieved, but component count and cost increase
Solution Approach 1:
The patent removes multiple electrolytic capacitors from the input filtering section, retaining only a single electrolytic capacitor. The filtering function previously distributed across multiple components is achieved through the combination of this single capacitor and the inherent filtering capability of the SMPS controller's feedback loop.
Solution Approach 2:
The single remaining electrolytic capacitor performs multiple functions: it provides bulk energy storage, filters mains ripple, and works in conjunction with the non-electrolytic capacitor to suppress SMPS-generated distortions. The TEA1520P controller's high gain feedback loop provides additional filtering, eliminating the need for separate filtering components.
3Ease of manufacture
If a single diode rectifier with non-electrolytic capacitor is used, then cost is reduced, but filtering capability must be maintained
Solution Approach 1:
The patent introduces a non-electrolytic capacitor as an intermediary filtering element that specifically targets high-frequency SMPS distortions. This capacitor works in conjunction with the single electrolytic capacitor to provide comprehensive filtering across different frequency ranges, maintaining filtering effectiveness while reducing component count.
Solution Approach 2:
The TEA1520P controller's high gain feedback loop acts as an active filtering mechanism that compensates for the reduced passive filtering capability. The feedback loop detects and corrects distortions generated by the SMPS operation, effectively filtering harmful frequencies without requiring additional passive components.
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 design simplifies the input section, reduces component count, and lowers costs by eliminating the need for multiple diodes and electrolytic capacitors, while maintaining performance and filtering effectiveness, thus providing a cheaper power converter solution.
Implementation Method 1
a single diode D connected in series with a non-electrolytic capacitor Cdiff
Implementation Method 2
The combination of the coil Ldiff and the non-electrolytic capacitor Cdiff only serves to filter distortions caused by the SMPS IC so that the mains network is not polluted
Implementation Method 3
only a single electrolytic capacitor Cin of typically 10 μF is needed for smoothening the output signal of the diode D
Data Source
AI summary
A power converter, comprising an input circuit having a single diode rectifier (D); and a switcher mode power supply IC (SMPS).