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DIY Stompboxes => Building your own stompbox => Topic started by: ExpAnonColin on January 06, 2004, 11:22:34 PM

Title: I want a triac optocoupler, right?
Post by: ExpAnonColin on January 06, 2004, 11:22:34 PM
Given that I want to be able to give it it's trigger current and have the 2 pins connect, basically like a current triggered SPST switch, I want a Triac driver output optocoupler, right?

-Colin
Title: I want a triac optocoupler, right?
Post by: Dean Hazelwanter on January 07, 2004, 09:20:03 AM
I'm not sure if there is such a thing as an optocoupler with built in triac, but I would recommend to use an external triac with whatever voltage and current capacity you need, with a MOC3010. The MOC3010 has a trigger diode (DIAC) out which directly controls the external triac.
Title: I want a triac optocoupler, right?
Post by: ExpAnonColin on January 07, 2004, 06:58:26 PM
Quote from: Dean HazelwanterI'm not sure if there is such a thing as an optocoupler with built in triac, but I would recommend to use an external triac with whatever voltage and current capacity you need, with a MOC3010. The MOC3010 has a trigger diode (DIAC) out which directly controls the external triac.

Yeah, so I DO want a "Triac driver output" one? Should have put the driver in the title, too...

-Colin
Title: I want a triac optocoupler, right?
Post by: Peter Snowberg on January 08, 2004, 09:51:43 AM
You actually want either a JFET output or a BJT output. The triac won't work for what you need. Once you trigger a triac, you need to stop the power from flowing through it to turn it off. In 60Hz AC, that off position happens 120 times per second as the power changes polarity. In DC, once it's on, it's on.

I would try a JFET unit like the H11F1, H11F2, or H11F3. That's the closest you'll get to an SPST.

Take care,
-Peter
Title: I want a triac optocoupler, right?
Post by: Dean Hazelwanter on January 08, 2004, 01:35:16 PM
Doh!!!

Sorry, Colin! As soon as I saw triac, I automatically assumed you wanted to control some line-powered (110/220 VAC) device!
Title: I want a triac optocoupler, right?
Post by: ExpAnonColin on January 08, 2004, 04:50:34 PM
Quote from: Peter SnowbergYou actually want either a JFET output or a BJT output. The triac won't work for what you need. Once you trigger a triac, you need to stop the power from flowing through it to turn it off. In 60Hz AC, that off position happens 120 times per second as the power changes polarity. In DC, once it's on, it's on.

I would try a JFET unit like the H11F1, H11F2, or H11F3. That's the closest you'll get to an SPST.

Take care,
-Peter

Thanks Pete.  My phyics teacher had done a project with optocouplers with triac driver outputs, that's what confused me.

-Colin
Title: I want a triac optocoupler, right?
Post by: Peter Snowberg on January 08, 2004, 07:39:49 PM
My pleasure. :)

If you're driving a high power triac to dim a light or control a motor, it's easiest to use an opto with the same style of logic, thus the triac optos.

Take care,
-Peter