I'm an electronics hobbist with relatively little experience and I'm playing around with Multisim to try to understand how to manipulate AC waveforms. Specifically, I would like to control the wave form with a function generator, optoisolator, and a triac. I'm unable to find an optoisolator in Multisim that has zero crossing, which as I understand it is somewhat important when trying to manipulate the waveform. Something like the MOC3041 (Output Type - AC, Triac, Zero Cross) is what I've been reading is a fairly standard component used to do this, but it's not listed in Multisim. Where should I look to find something that will work?

Any help would be much appreciated!

  • \$\begingroup\$ I don't know anything about mulitim, but can't you make your own components as needed? Also, the parameter "zero crossing detection" makes no sense for a optoisolator. Perhaps you are thinking about solid state relays? \$\endgroup\$ Commented Dec 10, 2011 at 17:43
  • \$\begingroup\$ @Olin Lathrop You'll have to bear with me. I'm fairly new to this. When I say optoisolator with zero crossing detection I mean one that will not switch on until the wave form is at zero. I could probably make my own, but since these are sold through electronics vendors, I would like to make something as close to reality as possible. I can't be sure that anything I created would be "real". Anyway, thanks for your comments. Maybe what I want to do isn't possible. That's an acceptable answer too. \$\endgroup\$
    – Matt Ruwe
    Commented Dec 10, 2011 at 18:44
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    \$\begingroup\$ here is some help cel.com/pdf/appnotes/an3005.pdf picaxeforum.co.uk/… \$\endgroup\$
    – user7005
    Commented Dec 12, 2011 at 20:42
  • \$\begingroup\$ @George Yes, that is helpful! I didn't consider the fact that PSPICE doesn't have the ability to do analysis of optics, which is probably by it doesn't include an optocoupler by default. Thank you! \$\endgroup\$
    – Matt Ruwe
    Commented Dec 12, 2011 at 23:49
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    \$\begingroup\$ Sorry I can't help with simulating that particular chip in Multisim. You might also want to experiment with non-zero-cross AC waveform manipulation -- light dimmer simulation and triac simulation. \$\endgroup\$
    – davidcary
    Commented Dec 15, 2011 at 15:43

1 Answer 1


Multisim is based on SPICE which is unable to simulate optical components like the MOC3041 that I used. Given this, the answer to the question is Multisim is unable to simulate a MOC3041.

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    \$\begingroup\$ I don't see any reason spice couldn't simulate the transfer function of an opto. Also, the MOC3041 isn't just an opto. It's an opto with a bunch of additional components on the output. For all intents and purposes, it's basically (most of) a solid-state relay (and the manufacturer calling it just an "Optoisolator" is really rather misleading). \$\endgroup\$ Commented Apr 11, 2012 at 6:04
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    \$\begingroup\$ Avago has a page of SPICE models for their opto-isolators here. You will have to add the zero-crossing detector and the TRIAC output stage yourself. \$\endgroup\$ Commented Apr 11, 2012 at 6:06
  • \$\begingroup\$ @Fake Name Great info, I was mostly posting this answer to my question because I didn't want to leave it open. If you would like to post you comment as an answer, I'll accept it. \$\endgroup\$
    – Matt Ruwe
    Commented Apr 11, 2012 at 10:57

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