Optical Isolation Power Circuit for Noise-Resistant Switching
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Solution Overview
Problem
Conventional power conversion circuits are susceptible to noise, leading to unstable operation of low-side switches and a high likelihood of through-currents, which reduces the lifespan of both low-side and high-side switches.
Innovation Solution
A power conversion circuit incorporating a control circuit, power switching element, driving circuit, light-receiving circuit, hold circuit, and comparison circuit, where the hold circuit maintains a high electric potential terminal voltage during OFF signals and supplies it as a comparison signal during ON signals, and the comparison circuit generates a bias voltage to accurately drive the power switching element, reducing erroneous ignition and through-currents.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If conventional detection circuit, switching circuit, and low-side switch form a closed loop for noise filtering, then noise resistance is improved, but the loop structure itself becomes susceptible to external noise affecting switch operation stability
Solution Approach 1:
The patent replaces the conventional electrical signal transmission system with an optical system. The light-emitting part converts electrical signals to optical signals, which are then transmitted to the light-receiving part that converts them back to electrical signals. This optical intermediary effectively isolates the control circuit from electrical noise, solving both the noise resistance and reliability issues simultaneously.
Solution Approach 2:
The patent introduces an optical intermediary (light-emitting part and light-receiving part) between the control circuit and the power switching element. This intermediary converts electrical signals to optical signals and back, creating an isolation barrier that prevents external electrical noise from affecting the switch operation, thereby improving both noise resistance and operational stability.
2Stability of the object's composition
If hold circuit supplies electric charge to high electric potential terminal during OFF signal, then voltage maintenance is improved, but erroneous ignition risk increases
Solution Approach 1:
The patent implements a feedback mechanism where the light-emitting part monitors the actual state of the power switching element and provides real-time information to the control circuit. The control circuit uses this feedback to make precise decisions about when to supply electric charge to the hold circuit, ensuring voltage maintenance only when the switch is genuinely OFF, thereby preventing erroneous ignition while maintaining voltage stability.
Solution Approach 2:
The patent uses optical signal transmission to replace direct electrical connection between the control circuit and power switching element. The light-emitting part and light-receiving part create an isolation barrier that prevents noise-induced erroneous ignition, while the control circuit uses feedback from the optical signal to accurately control when to supply electric charge to the hold circuit, achieving both voltage maintenance and error prevention.
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 configuration stabilizes the operation of the power switching element, reduces the occurrence of through-currents, and prolongs the lifespan of the power switching elements by minimizing the impact of external noise, ensuring stable and long-term operation of the power conversion circuit.
Implementation Method 1
a light-emitting part that emits light in accordance with an energization current
Implementation Method 2
The light-receiving circuit receives the light emitted by the light-emitting part and generates an energization signal that is an electric signal based on intensity of the light
Data Source
AI summary
A light-receiving circuit receives light emitted by a light-emitting part and generates an energization signal that is an electric current based on intensity of the light. A hold circuit is configured to supply an electric charge of an energization signal to a high electric potential terminal and not to decrease a voltage of the high electric potential terminal in a case where a control circuit is sending an OFF signal. Furthermore, the hold circuit is configured not to supply the electric charge of the energization signal to the high electric potential terminal and to keep the voltage of the high electric potential terminal in a case where the control circuit is sending an ON signal. A comparison circuit compares a comparison signal and a reference signal, generates a bias voltage based on a result of the comparison between the comparison signal and the reference signal, and feeds back the bias voltage as a reference signal. A driving circuit supplies the bias voltage to a reference terminal while the control circuit is sending the OFF signal.