AC mains optocoupler

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I am trying to safely isolate AC mains through an optocoupler. The output is a square wave, yet want I want is a sine wave output, like the AC input. Do I need a special type of optocoupler? I'm not finding much on Google on this. Any help would be greatly appreciated.

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Are you shure that what you really need is not a transformer?

Guillem.

Guillem.
"Common sense is the least common of the senses" Anonymous.

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I use small transformer like a BV201 http://www.hahn-trafo.com/

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The key name to search is 'linear optocoupler'.
I used a device by infineon/siemens a few years back, the IL300. It is no longer in production, but it might be of interest. The chip required an op-amp feedback cct to get a linear response. Note that this device was for isolating a signal only, not tapping off power.
I would favour the transformer solution, but I do not know your requirements.

http://docs-asia.electrocomponents.com/webdocs/0028/0900766b80028881.pdf

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Reduce the signal going into the LED with a larger series resistor.

Lower the gain of the transistor output by reducing the load resistor value.

But, with a simple opto, you will ONLY get every-other half-cycle. Even with the "linear" ones. If you want a full 360 degree sine, a transformer is needed.

Jim

 

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ka7ehk wrote:

But, with a simple opto, you will ONLY get every-other half-cycle. Even with the "linear" ones.
Jim

Maybe use an AC Optpcoupler ie. H11AA1
http://www.fairchildsemi.com/ds/...

/Bingo

Btw: I was thinking about using one of these as AC optocoupler (Zero Crossing) , and maybe also as Triac driver , it has 2 functions. Would that be a god chip for that ?? , i can't seem to find the delay through the AC Opto , so i don't know if it's good for zerocrossing.

Edit: I don't think its a good choice , it seems there can be a 3 ms delay on the output fet.

http://www.clare.com/home/pdfs.n...$file/Ts117.pdf

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Broxbourne wrote:
The key name to search is 'linear optocoupler'.
I used a device by infineon/siemens a few years back, the IL300. It is no longer in production, but it might be of interest. The chip required an op-amp feedback cct to get a linear response. Note that this device was for isolating a signal only, not tapping off power.
I would favour the transformer solution, but I do not know your requirements.

http://docs-asia.electrocomponents.com/webdocs/0028/0900766b80028881.pdf

I have used the IL300-x also in some production devices and for some apps I prefer the transformer ....

try mouser if you want to try them

http://www.mouser.com/search/ProductDetail.aspx?R=IL300virtualkey61370000virtualkey782-IL300