BTA40-600B, optocoupler and snubber

DanielGouvea · ‎2025-03-29

I intend to design a microcontroller circuit with a BTA40-600B RD91 to control the power delivered to a heating resistor (220Vrms, 12Ω, 4KW). I thought about using the MOC3023 to mediate the activation of the BTA40, but I don't know if it is the most suitable optocoupler. Another question is about the snubber circuit. The load is purely resistive, so is a snubber circuit really necessary? Thanks for the help.

Peter BENSCH · ‎2025-03-31

Welcome @DanielGouvea, to the community!

The output current of the MOC3023 is just sufficient to control the BTA40. However, the BTA40 is not a snubberless TRIAC and therefore requires a snubber circuit. Further information on this and the design of the snubber can also be found in application note AN5114, section 2.4.

Hope that helps?

Regards
/Peter

In order to give better visibility on the answered topics, please click on Accept as Solution on the reply which solved your issue or answered your question.

View solution in original post

Peter BENSCH · ‎2025-03-31

Welcome @DanielGouvea, to the community!

The output current of the MOC3023 is just sufficient to control the BTA40. However, the BTA40 is not a snubberless TRIAC and therefore requires a snubber circuit. Further information on this and the design of the snubber can also be found in application note AN5114, section 2.4.

Hope that helps?

Regards
/Peter

In order to give better visibility on the answered topics, please click on Accept as Solution on the reply which solved your issue or answered your question.