Is there a recommended methode to an insulated control of the ACST435-8?

[AHabe.1]

..

[Peter BENSCH]

Yes, by implementing galvanic isolation, e.g. using an optocoupler or zero crossing optocoupler, depending on your needs.

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Good luck!

/Peter

[AHabe.1]

Yes, of course we have to add an optocoupler or optotriac, but are there special requirements for the optocoupler or for the connection of optocoupler to the ACST435?

Is there an application note?

Thank you in advance.

Albert

[Peter BENSCH]

It always depends on your load - inductive/resistive/capacitive/mixture/etc.

You can find some information in e.g. AN4993, additional information can usually be found in the application notes from the suppliers of the (zero crossing) optocoupler.

Regards

/Peter

[AHabe.1]

Thank you Peter.

The AN4993 is very helpful.

[AHabe.1]

Hi Peter,

now I have found the AN5114 on ST site.

This AN describes in a good manner the isolated controll of a TRIAC.

In chapter 3.3.1 there are the equations for determining the resistors.

But it seems that this equations do not really work for a ACST435 with 35mA gate current and for a photo-TRIAC with 1A surge current.

Could you please give me the recommended values for this TRIAC combination?

Thank you in advance

Albert

[Peter BENSCH]

The values for the surrounding devices depend on several factors of the environment. That's why ST also provides TRIAC, SCR and ACS Simulator to simulate is using your parameters, like e.g. load type, conduction mode, controller topology and heat sink.

Regards

/Peter