Single-Stage Forward Converter for Multi-Voltage Power Supply
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Solution Overview
Problem
Conventional power supply circuits require multiple stages for AC to DC voltage conversion, leading to inefficiencies and electromagnetic interference (EMI), and struggle to maintain precise voltage levels across various DC output voltages, often necessitating significant capacitance and additional filtering stages.
Innovation Solution
A single-stage power supply system that uses a first electrical signal alternating between high and low voltages with a synchronized second signal to generate a gated electrical signal, filtered to produce a DC output voltage, with the duty cycle controlled based on voltage differences to maintain optimal voltage levels across multiple DC output voltages.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a two-stage conversion process is used with a sizeable transformer for energy storage, then the power supply can convert AC voltage to multiple DC voltage levels, but the device complexity and component count increase
Solution Approach 1:
The patent merges the first-stage high-voltage DC generation and second-stage low-voltage DC conversion into a single integrated forward converter stage. The primary winding generates high-voltage DC while the secondary winding simultaneously provides low-voltage DC outputs, eliminating the need for separate conversion stages and reducing overall system complexity while maintaining the capability to provide multiple DC voltage levels.
2Reliability
If significant capacitance is added at the output of the first stage to counteract negative resistance effect, then peak current requirements are satisfied, but the device complexity and component count increase
Solution Approach 1:
The patent extracts and eliminates the problematic negative resistance effect by using separate primary and secondary windings instead of deriving low-voltage outputs from a high-voltage DC bus. This removes the need for large capacitance to counteract the negative resistance effect, as each winding independently provides its required current without interfering with the other.
3Object-affected harmful factors
If a two-stage EMI filter is incorporated to reduce high-ripple current at the input of the boost converter, then electromagnetic interference is diminished, but the device complexity and component count increase
Solution Approach 1:
The patent removes the source of electromagnetic interference by eliminating the boost converter entirely. Instead of using a boost converter that generates high-ripple current requiring complex EMI filtering, the invention uses a forward converter topology where the primary winding directly generates the high-voltage DC output, avoiding the problematic high-frequency switching currents that cause EMI.
4Manufacturing precision
If the power supply monitors and alters the first stage operation to maintain narrow voltage range, then output voltage precision is maintained, but the device complexity increases
Solution Approach 1:
The patent implements feedback control by monitoring the high-voltage DC output from the primary winding and using this information to adjust the operation of the forward converter. This feedback mechanism maintains precise voltage levels at the high-voltage DC output, which in turn ensures stable low-voltage DC outputs from the secondary winding, achieving voltage precision through controlled feedback rather than complex monitoring of multiple outputs.
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 allows for efficient, single-stage conversion of AC to DC, reducing component count, minimizing EMI, and enabling precise regulation of multiple DC output voltages locally at each power supply circuit, enhancing accuracy and reducing the need for extensive feedback and filtering.
Implementation Method 1
filters the gated electrical signal to generate a DC output voltage
Data Source
AI summary
A method of supplying direct-current (DC) power is presented herein. In the method, a first electrical signal and a second electrical signal are received. The first electrical signal alternates between a high voltage and a low voltage according to a constant duty cycle. The second electrical signal is synchronized with the first electrical signal. The first electrical signal is gated using the second electrical signal to produce a gated electrical signal with a duty cycle less than the duty cycle of the first electrical signal. The gated electrical signal is filtered to generate a DC output voltage. A difference between the generated DC output voltage and a reference DC voltage is determined. The duty cycle of the gated electrical signal is controlled by controlling the gating of the first electrical signal based on the difference.