BTA40-600B, optocoupler and snubber

[DanielGouvea]

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]

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