STMicroelectronics AN3168 Application note Non-insulated SCR / Triac control circuits

Introduction of non-insulated SCR / triac control circuits

Brand: STMicroelectronics
Document type: Application Note
Language: English
Pages: 20
File format: PDF
File size: 316 KB
Published: 06 August, 2012
Updated: 30 September, 2023
MD5 checksum: 9119743C865C741309A1650EEEA0B70C
PDF: STMicroelectronics AN3168 Application note Non-insulated SCR / Triac control circuits PDF

About this manual

The document explains that low-voltage electronic devices in AC applications can be powered using capacitive, linear, or switch-mode power supplies. It focuses specifically on non-insulated power supplies and details the triggering quadrants and key parameters for SCRs, Triacs, ACS, and ACST components.

What's inside

Triggering quadrants
Key parameters (IGT, VGT, IL)
Gate resistor value definition
SCR and Triac triggering circuit with positive power supply
Triac and ACS / ACST triggering circuit with negative power supply
Diac control circuit
Examples of linear power supply
Examples of capacitive power supply

Specifications

Triggering quadrants for Standard Triac	Q1, Q2, Q3, Q4
Triggering quadrants for Snubberless and logic level Triac	Q1, Q2, Q3
IGT variation rate with temperature	2 mV/°C

Frequently asked questions

Which triggering quadrants are recommended for Triacs and ACS / ACST devices?

Working in Q2 / Q3 quadrants is advised to decrease board consumption and increase reliability.

Can a negative power supply be used with SCR devices?

No, this topology can be used with all Triacs, ACS and ACST, but not with SCR.

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