Hi AAC,

I would like a module/circuit that could deliver constant output AC voltage (110v AC) over varying input voltages for i.e. different geographies.
The input voltage would mostly be greater than the desired 110AC output with the exception of some regions (japan) which are slightly lower.
If necessary I could make an exception for those regions.

The 110ac output is required to power a 100W AC lamp so a decent power rating is required.

It is my understanding that a conventional step down transformer will not provide a fixed AC output across a range of inputs
My ideal scenario would be a lost cost module I could integrate into my system, however a custom board design would be possible too.

I would appreciate some suggestions/advice.

Many thanks.

Ade.

 

100w is not all that much, is this a N.A. AC product? As the common supply now is 120vac.
Most products have some leeway as to tolerance, and also various service supplies are not that precise over time.
A simple small Toroidal with a 120v/240v primary, with if necessary, a couple of primary taps would do it economically.
Max.

 

What about different line frequencies?
Is your lamp sensitive to that?

 

Hi Guys

thanks for the feedback and suggestion. I have a couple of questions.

If i used a Toroidal transformer with a 110AC secondary, would the AC output at the secondary winding not change if the AC input on the primary winding changes?

The lamp should accommodate the variance in frequency without issue in this application.

Thanks

Ade.

 

Yes, the secondary changes proportionately, but most devices are at least ±10% tolerant.
Max.

 

Hi Max,

thanks. Apologies I am still not 100% clear. AC stuff is new to me.

So are toroidals available that can accommodate either 120 or 240 AC in and still deliver 110AC out (for either of the input voltages?)?

How would that be wired to the AC inlet? Would you need a switch to select what AC source you are using?

Many thanks.

Ade.

 

The primary of the Txfmr normally has a dual 120v winding which is either connected parallel or series to accommodate the supply it is used on, both deliver the same secondary voltage.
If switching frequently between supplies, then a suitable switch would be needed, as is used on some SMPS and PC's.
Max.