Flyback Converter Communication Circuit Eliminates Optical Isolators
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional adaptive travel adaptor systems rely on optical isolators for communication between the secondary and primary sides of a flyback power converter, increasing costs and reducing system reliability.
Innovation Solution
A communication circuit using a pre-defined synchronous rectifier switch encoding method eliminates the need for optical isolation by transferring messages between the secondary and primary sides through a transformer, employing a protocol decoder, message encoder, switching circuit, and detection circuit to encode and decode messages without additional components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an optical isolator is used for transferring protocol messages from the secondary side to the primary side, then communication between sides is achieved, but system cost increases and reliability decreases
Solution Approach 1:
The patent removes the optical isolator from the communication circuit, extracting this problematic component entirely. The secondary side protocol IC directly modulates the primary side switching transistor gate signal through the existing transformer coupling, eliminating the need for optical isolation while maintaining communication functionality.
Solution Approach 2:
The existing transformer coupling, originally designed solely for power transfer, is made to serve dual purposes: power transmission and communication signal transfer. The protocol messages are embedded within the power transfer cycle timing, allowing the same magnetic coupling structure to handle both energy and information transfer without additional components.
2Reliability
If an optical isolator is used for transferring protocol messages, then communication is established, but system cost increases
Solution Approach 1:
The optical isolator component is completely removed from the bill of materials. Communication is achieved by utilizing the existing transformer coupling and switching transistor gate drive circuitry already present in the flyback converter design, eliminating the need for expensive optical isolation components.
Solution Approach 2:
The system uses its own existing components (transformer, switching transistor, gate driver) to perform the communication function. The protocol messages are transmitted by modulating the timing of the switching transistor gate signal, which is already being driven by the controller, making the existing circuitry serve dual purposes.
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 solution provides a cost-effective and reliable communication method between the secondary and primary sides of an adaptive flyback power converter, enhancing system reliability and reducing costs by eliminating the need for optical isolators.
Implementation Method 1
a communication circuit using a pre-defined synchronous rectifier switch encoding method eliminates the need for optical isolation by transferring messages between the secondary and primary sides through a transformer
Data Source
AI summary
A method for communicating with a power converter comprises initiating a communication sequence by sensing a first distortion of a sensed waveform during a discharge period of a first power transfer cycle of the power converter. The sensed waveform is proportional to a secondary current of the power converter. At a primary side of the power converter, a data bit is received from a secondary side of the power converter, by sensing a second distortion to represent one state of the data bit and sending an absence of the second distortion to represent another state of the data bit. The secondary distortion is applied to the secondary current during the discharge period of a subsequent power transfer cycle.