Need help with a circuit again

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1moldmaker
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Need help with a circuit again

Post by 1moldmaker » Mon Mar 26, 2018 3:53 pm

I was wondering if there was a way to add a sensitive gate triac to this Schmitt trigger circuit. D2 is normally on. Press S1 and D2 turns off and D1 turns on and stays on for two seconds after switch is released. What I would like it do is instead of turning on and off an led, is turning on and off a 12 vac relay or a 12 vac light, and possibly making this a spdt solid state relay for low voltage ac 10-20vac.
thanks
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sghioto
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Re: Need help with a circuit again

Post by sghioto » Tue Mar 27, 2018 5:23 am

Easiest solution is to use a solid state relay or what they call an opto-triac. Depending on the current required a MOC3020 may be adequate.
SG

1moldmaker
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Re: Need help with a circuit again

Post by 1moldmaker » Tue Mar 27, 2018 6:45 am

I will be pulling some amperage, up to 10 amps max,
Would I put the optocoupler where the leds would go?

1moldmaker
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Re: Need help with a circuit again

Post by 1moldmaker » Tue Mar 27, 2018 5:39 pm

One other thing, I was wondering if I could put the gate of the triac with the 1k resistor instead of the led, would that trigger the triac?

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dacflyer
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Re: Need help with a circuit again

Post by dacflyer » Wed Mar 28, 2018 7:54 am

you can get SSL as high as 100 amps or more...
i got a bunch that are good for 25 amps. i think the input is 24 volt range,, i'd have to look..,

1moldmaker
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Re: Need help with a circuit again

Post by 1moldmaker » Wed Mar 28, 2018 8:21 am

What is an SSL?

sghioto
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Re: Need help with a circuit again

Post by sghioto » Wed Mar 28, 2018 6:51 pm

One other thing, I was wondering if I could put the gate of the triac with the 1k resistor instead of the led, would that trigger the triac
Not in this case as the triac will be on continuous. Best solution is to use an opto-isolator.
For 10 amp loads you can use the MOC3020 to drive a high current triac such as BTA16 rated at 16 amps.
SG
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1moldmaker
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Re: Need help with a circuit again

Post by 1moldmaker » Thu Mar 29, 2018 5:49 am

Thanks again, that's is exactly what I was looking for,

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haklesup
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Re: Need help with a circuit again

Post by haklesup » Thu Mar 29, 2018 12:21 pm

SSL?, I think he means SSR, Solid State Relay. Lots on Digikey but 12V ones were expensive. The nice part about an opto-isolator is that the switching and load supplies can be completely separate.

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dacflyer
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Re: Need help with a circuit again

Post by dacflyer » Mon Apr 02, 2018 12:34 pm

1moldmaker >>> solid state relay

check out CRYDOM solid state relays...they got all kinds..

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