Dimmer working principle

[zohaib]

dimmer working

hello every one!
can some one explain me the working principle of electronics dimmer based on triac?
which factor causes the variation of voltage?
does change in frequency cause it?
thanx

 

[kishore2k4]

working principle of ups

Normal dimmers, the one we use everyday don't/can't change the output frequency.

If you are aware of the working of a phase-controlled rectifier then this is easy to understand. A dimmer simply controls the conduction on both sides of the sine-wave.

Say if you want half the power to be applied, then the firing angle will be set appropriately and therby applying less volt-sec and when you integrate it you'll know that average voltage applied is half.

 

[zohaib]

thanx for your answer
actually i am designing a ups and for its battery charging circuit i need to regulate the ac power i think the utilization of a dimmer circuit can be useful

 

[kishore2k4]

You can use a bridge-rectifier with a filter capacitor(electrolytic) after the dimmer to produce a, more or less, constant DC voltage that can used to charge your batter but the whole solution is ad-hoc and you better do some extensive testing at low voltages before you move to line voltage.

So it is like
AC Line->Transformer(for testing at low voltages)->Dimmer->Bridget-Rectifier->Filter/Storage Capacitor(Electrolytic)->Fuse->Battery to be charged.

Also be very careful when testing at line voltages, some shocks can be pretty nasty and leave you numb for several minutes.