Switching Control Circuit Primary Winding Feedback
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Solution Overview
Problem
Conventional switching power supply devices require additional insulating space and increased costs due to the need for extra windings or photocouplers for feedback signal processing, especially in applications like general-purpose intelligent power modules and vehicle-mounted systems.
Innovation Solution
A switching control circuit that includes a differential amplifier and a filter circuit to extract detection voltage from the primary winding of a transformer, allowing for control of the switching element without the need for additional windings or photocouplers, thereby reducing space and cost.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional switching power supply device uses additional windings or photocouplers for feedback signal processing, then the feedback control function is achieved, but the insulating space requirement increases and the mounting space and cost increase
Solution Approach 1:
The patent merges the feedback signal acquisition function with the existing primary winding by detecting voltage at both ends of the primary winding. This eliminates the need for separate auxiliary windings or photocoupler-based insulating feedback circuits, thereby reducing mounting space while maintaining feedback control functionality.
Solution Approach 2:
The primary winding serves multiple functions: power transfer and feedback signal generation. By utilizing the voltage across the primary winding for both purposes, the patent eliminates the need for dedicated feedback windings or insulating components, reducing overall circuit complexity and space requirements.
2Area of stationary object
If a distributed power supply system is adopted to eliminate extra insulating space, then the mounting space is reduced, but each power supply requires additional windings or insulating feedback circuits resulting in increased mounting space and cost
Solution Approach 1:
The patent combines the feedback signal detection function with the primary winding voltage measurement. This merging eliminates the need for separate feedback windings or insulating feedback circuits in distributed power supply systems, reducing both insulating space requirements and circuit complexity.
Solution Approach 2:
The primary winding provides its own voltage signal for feedback purposes without requiring external feedback windings or insulating components. This self-service approach simplifies the circuit configuration and reduces the need for additional components in distributed power supply architectures.
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
The solution achieves miniaturization, weight reduction, and resource savings while effectively controlling the switching element, eliminating the need for extra components and simplifying the circuit configuration.
Implementation Method 1
a differential amplifier that differentially amplifies voltages at both ends of the primary winding part to obtain an amplified voltage
Implementation Method 2
a filter circuit that extracts low frequency components of the amplified voltage to obtain a detection voltage
Implementation Method 3
a switching element that converts a direct current input voltage into an alternating current voltage by an on/off operation
Data Source
AI summary
A voltage detecting circuit of the present invention is formed of a differential amplifier and an H-detection filter circuit, and the differential amplifier amplifies a potential difference between an input voltage and a primary-side voltage to obtain a differential amplified voltage. The H-detection filter circuit extracts low frequency components of the differential amplified voltage to output a detection voltage. A DC/DC control IC outputs, to a control electrode of a transistor, a PWM signal obtained by shaping a pulse width based on the detection voltage, to thereby control an on/off operation of the transistor.