I ran into a problem lately, with using triac and because I don't have any engineering school just yet, I could make a mistake... and bad circuits with mains electricity? meh bad idea...

so, I have seen few circuits on Internet like this - that's what I found

I would use some kind of optocoupler triac driver... MOC30XX family - but what exact type? Since I want to use it on 240AC I guess the resistors need to be selected precisely... but how?

and about "if it is an inductive load" it is... but I have no idea how to measure "how much inductive it is"

I thank you for any answer or if you just redirect me somewhere I can find answer.

  • \$\begingroup\$ What is your load? \$\endgroup\$ – user133493 Mar 14 '17 at 11:21
  • \$\begingroup\$ it's a motor... but it has some unknown circuitry inside that protects it from going out of predefined position, or if it is forced to stop it turns off as well \$\endgroup\$ – AltHaoX Mar 14 '17 at 11:24
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    \$\begingroup\$ What is the application? This may be an xy problem. Are you trying to control the motor speed or just switch it on and off? The TRIAC is the wrong solution in the latter case. \$\endgroup\$ – user133493 Mar 14 '17 at 11:31
  • \$\begingroup\$ @replete I don't need any switching application, just ON our OFF state... I would like to know the values i should use, and the type of MOC30XX \$\endgroup\$ – AltHaoX Mar 14 '17 at 11:35
  • \$\begingroup\$ A relay makes much more sense in this application. If you insist on using an optotriac setup, a zero-crossing variant (MOC304x) makes more sense. Google a datasheet, there are several manufacturers. For example, Fairchild's datasheet shows you a typical solution in Figure 15. There are answers on this site to questions about designing the values for passives around the TRIAC, for example electronics.stackexchange.com/questions/55368/… \$\endgroup\$ – user133493 Mar 14 '17 at 11:42

Correct use of triacs is not an easy task and requires some clarification. If you do not have electronics experience, it will be much safer for you to use a relay. It's simple to implement.


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