Antiparallel Thyristor Switch for AC Conduction Control

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Solution Overview

Problem

Existing control switches for alternating current (AC) voltage in electronic devices suffer from uncontrolled conduction issues when current direction changes, and there is a need for reliable bidirectional voltage and current switches to manage power supply effectively.

Innovation Solution

A bidirectional switch comprising two thyristors arranged in antiparallel, each controlled by its own driver circuit, with integrated diodes to protect against reverse polarity, and a control device with MOS-type transistors and parasitic diodes for reliable operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a control switch is used to control AC power supply to a load, then the power supply can be controlled, but uncontrolled conduction occurs when current direction changes

Engineering Contradiction:
Improvereliability of power supply controlVSAvoiduncontrolled conduction
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent divides the single switch control function into two separate thyristors (T1 and T2) arranged in antiparallel configuration. Each thyristor handles one current direction independently with its own dedicated driver circuit, eliminating the uncontrolled conduction problem that occurs in single-switch AC control systems when current direction changes.

Inventive Principle:
Principle #1Segmentation

2Reliability

If two thyristors with separate driver circuits are used to prevent uncontrolled conduction, then reliability improves, but device complexity increases

Engineering Contradiction:
Improvebidirectional power supply controlVSAvoidswitch structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent integrates the two separate driver circuits (Driv1 and Driv2) and thyristor control systems into a single unified switch device housing. This merging approach maintains the reliability benefits of separate thyristor control while reducing overall device complexity and simplifying installation by providing a compact, integrated bidirectional AC switch solution.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP4687294A1Switch
Publication Date: 2026.02.04 STMICROELECTRONICS INT NV
  • EP4687294A1 patent drawingFigure 1~2
  • EP4687294A1 patent drawingFigure 3
  • EP4687294A1 patent drawingFigure 4

AI summary

This description relates to a control device (Driv131, Driv132) of a switch (130) comprising: - a first control circuit (Driv131) of said switch (130) referenced to a first terminal (N110) adapted to receive an alternating potential, formed on a first substrate, and comprising a first diode whose anode is connected to said first substrate; - a second control circuit (Driv132) referenced to a second terminal (GND100) adapted to receive a reference potential, formed on a second substrate, and comprising a second diode whose anode is connected to said second substrate; in which the cathode of said first diode is connected to said second control circuit (Driv132), and the cathode of said second diode is connected to said first control circuit (Driv131).