How many turn numbers at the primary side of the transformer with a centre taped secondary side producing 14.2-0-14.2v. Input voltage is 220vac.

 

There is nowhere near enough information in your question, but (turns out)/(turns in) is approximately how you figure the answer. You will need about 7.74 times as many turns in the primary as there are in the secondary.

 

Set your problem up as a RATIO

If your 220 Volt primary has 220 turns
Then your secondary would have 14 or 15 turns.

Not exact but close enough to work with.


If your primary has 50 turns
50 /220 = x/14

 

Also can diode add voltage in a centre taped transformer? For example from 10-0-10v to 12-0-12v how can i use it 2 add output voltage?

 

You can't. Diodes don't generate voltage.

 

Diodes are used to RECTIFY the AC voltage into DC voltage.

 

Kermit2,my problem is on what exactly we mean by turns,and how can i measure that this is a single turn.so pliz help me.

 

For a standard EI transformer, 1 turn is one complete loop around the middle post. The actual number depends on area of the center post, voltage and frequency you want it to use with.

 

True! Diodes don't generate voltage but they can, in conjunction with capacitors, be wired into a voltage doubler circuit. Right?

 

@ wmodavis Not the way this guy wants it. Look at post 4. He wants to add 2 RMS volts to each winding. You simply can't teach a diode to do that.

 

I simply want to connect a diode on each end side of a centre tap transformer just b'cos my transforme normally generate 6.3v-0-6.3v and i want it 2 generate 7 volts to each side in the secondary side so that to get 14.3v-0-14.3v can diode generate? If not so what can i do to get that amount of voltage?

 

The transformer generates 2x6.3V AC? And you want to get 2x14.3V DC?
Then a voltage tripler could get you near that. What current can the transformer supply and how much do you need?
Remember you can´t get more power than the transformer is rated for.

 

The mods might take notice that this is a re-post of the original thread.
http://forum.allaboutcircuits.com/showthread.php?t=53806

 

Ok! Thanx 4 ur advice.bt the transformer still work with a shortage of voltage,so i will work on it later coz i dont have enough time 2 repair it again till when am at hom coz now am tight with school.so thanx 4 ur advice i wil work on it,thanx am from TANZANIA