TRIAC integrated random phase optocoupler

Thread Starter

denison

Joined Oct 13, 2018
330
Hi all, Trying to find a TRIAC with an integrated random phase OPTO coupler. Don't know if there is such a beast but it sure would be useful for analog and digital control.
I am using a random phase triac optocoupler to turn on a triac for phase control.
The circuit would be simpler without the opto. I can't see any reason why the opto could not be integrated onto the high power triac. This would then be useful for both computer and analog control.
Does anybody know of such a triac.
 

schmitt trigger

Joined Jul 12, 2010
903
Think about it for a minute.

There are circuit instances where triggering with a pulse transformer, Diac or DC is more advantageous than with an optocoupler. This would mean that companies would have to keep manufacturing standard Triacs in addition to the optocoupled Triacs.
Probably doesn’t make financial sense.
 

Thread Starter

denison

Joined Oct 13, 2018
330
Think about it for a minute.

There are circuit instances where triggering with a pulse transformer, Diac or DC is more advantageous than with an optocoupler. This would mean that companies would have to keep manufacturing standard Triacs in addition to the optocoupled Triacs.
Probably doesn’t make financial sense.
an optocoupler allows isolation between the low power controlling circuit and a mains connection. If a company made such a triac I am sure it would be an immediate financial success with designers clamouring for such a triac. Perhaps they will take the hint if they see this posting.
 

Thread Starter

denison

Joined Oct 13, 2018
330
It's called a Solid State Relay.
Thanks Ian. That should do it I think. As long as the input signal is correct as in a connection to a random phase opto coupler and triac you should be able to get phase control from the ac output.
I should then be able to replace the random phase opto and triac with the solid state relay. I actually have one already with an output from 24 to 380vac. So 240vac is covered. Have to find out the power rating but looks like a pretty good heat sink at the base.
 

Thread Starter

denison

Joined Oct 13, 2018
330
Thanks Ian. That should do it I think. As long as the input signal is correct as in a connection to a random phase opto coupler and triac you should be able to get phase control from the ac output.
I should then be able to replace the random phase opto and triac with the solid state relay. I actually have one already with an output from 24 to 380vac. So 240vac is covered. Have to find out the power rating but looks like a pretty good heat sink at the base.
 

schmitt trigger

Joined Jul 12, 2010
903
an optocoupler allows isolation between the low power controlling circuit and a mains connection. If a company made such a triac I am sure it would be an immediate financial success with designers clamouring for such a triac. Perhaps they will take the hint if they see this posting.
So does a pulse transformer offer isolation, with the additional advantage that it provides hard-triggering.
And, as I mentioned previously, there are many applications which do not require isolation. For instance, a plain light dimmer.

You are sure it would be a financial success?
Well, why don’t you write a letter to the Littelfuse Corporation or ST Microelectronics and propose your idea? Posting on a blog and arguing with strangers won’t advance your proposal.
 
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