Light Dimmer with triacs, using 110v instead of 220v

Thread Starter

ofest

Joined Feb 2, 2013
4
Hi everyone, well my doubt is the next one, I was searching for a simple project I could make with triacs and I found this one.



Well the diagram says it will work with a 220v AC , but in my house the electrical connection is of 110v, my main doubt is will this work with the previous diagram, or will I need to make any modifications in it?

Thanks a lot guys I´m a little lost on this one, any comment is appreciated.
 

THE_RB

Joined Feb 11, 2008
5,438
Yes it needs to be modified to work on 110v. The circuit uses RC time delays to adjust the trigger point where the DIAC conducts and fires the TRIAC.

On 110v AC the R in the RC delay will need to be reduced.

Since this is a very common and typical DIAC based light dimmer, your best option is just to google a bit more and find some examples of a 110v AC version and see what parts values they use. :)
 

t06afre

Joined May 11, 2009
5,934
Even it may be fun to build a light dimmer. It will be a highly unsafe construction. I highly recommend NOT using it for any purpose other than educational purpose.
 

THE_RB

Joined Feb 11, 2008
5,438
Agreed, the pot gives a 471:1 range on the first RC but the second RC is fixed.

Maybe someone with a simulator could test run it at 110v AC?

It would be a shame to build it and have a pot that does nothing for half its rotation.

If that circuit was originally setup well with timings for 220v AC, you could just halve the values of both caps and it should have similar timings on 110v AC. You might need to adjust for 50/60Hz too, but that's much less of an issue than the 2:1 voltage issue.
 

Thread Starter

ofest

Joined Feb 2, 2013
4
I found a somewhat similar circuit with the following diagram for 117 VAC, I just found out that in my house the voltage is 127VAC, will it be ok to implement it? or still would I need to modify it?

 

THE_RB

Joined Feb 11, 2008
5,438
That should probably work fine. You should include a fast blow fuse like a 2A fuse for safety (choose a low amps fuse that will still allow your lights to have full power).

ALSO as people have already said; this is powered from live AC mains and is a very dangerous circuit and is not something to "play with"! If you are determined to build it you need to do so in a very safe manner with everything mounted properly and the entire device fully insulated from any users, in a sealed box.

Do you have any experience building mains powered electronics? If not, you should be asking some safety questions and reading up on the subject.

Knowing the parts values is only a tiny bit of what you need to know to build it safe and reliable!
 
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