How to achieve 120V constant output if input is 120 or 277v

oh sorry for not mentioning that, its AC

5W power it shud be small enough .

tanks for response sincerely jayesh

AC or DC? How much power, 1 GW or 1mW? how much space?

martin

And how suddenly does it switch between voltages?

If there is essentially no switching -- you just sometimes plug it into a

120V line, and other times a 277V line -- then I'm thinking of a transformer, a relay to switch the transformer in or out of the circuit, and a voltage-sensing circuit.

Where is the line voltage 277V?

hi i just dont wanna use any transformer no magnetics so any other solution .

thanks for ur help sincerely jayesh

--- It would be nice if, when you have a problem and you need a solution, you'd state all of the requirements at the same time. For example, had you stated in the beginning that you didn't want to use a transformer you would have saved someone the time he wasted in coming up with a solution you can't/don't want to use. Also, you haven't stated what the load looks like. That is, does it draw a constant current with 120VAC on it? If it does then there's a very simple solution for your problem, but I'm not going to waste my time telling you about it unless you tell us precisely what you want.

BTW, why can't you use a transformer, and why don't you learn to write properly? Or take it to seb?

-- John Fields Professional Circuit Designer

and

277V is the phase to neutral voltage from a 480V 3 phase source.

hi thank u for suggestions and sorry for the trouble actually i want to use only electronic vircuitry without magnetics as thats requirement. Now there is a component called thermal protector which needs a 120V contsant input so i wanna make it work say if u provide 120 or 277v theTP shud work so v ned to convert 277 to 120V that can be done by triac but when its 120V it shud by pass it.

So i wanna know how it can be done and relay is one way any other suggestion plz.

Sorry for inconvenience

thank u

--
You devil, you! :-)

Not all of them. Amperite used to make thermal time delay relays, and don't forget solid state relays.

--
Michael A. Terrell
Central Florida

A relay uses a magnet.

Ken

Monday morning, only one cup of tea so far........

Ken

Ouch! Another smart-alec bites the dust.

:-)

Ken