# Transformer Characteristics

Discussion in 'General Electronics Chat' started by USNtron75, Nov 24, 2011.

1. ### USNtron75 Thread Starter New Member

Dec 14, 2010
12
0
If you will, consider a 120 VAC power transformer that steps down to 12 VAC with a center-tapped secondary winding. Now, I understand why there's 12 VAC at each of the outside lines, but why is is the voltage cut in half on the ceter line? Does the coil impede (build pressure) the voltage, thereby cutting it in half at the center line? Ultimately, what determines the available voltage on the secondary side? Is it the ratio between the primary and secondary sides? Thank You!!

Einstein said, " I just want to learn to think like God. Everything else is details. "

Tron 75

2. ### SgtWookie Expert

Jul 17, 2007
22,183
1,728
DING! DING! DING! We have a winner!

It is the ratio of turns from the primary to the secondary side.

If you have a 120v primary and a split 12v secondary, then the primary has 100 turns to the secondary's 5 for each side of the center tap.

3. ### Yako New Member

Nov 24, 2011
245
2
Don't forget to tell them about eddy loss current. How does the voltage magically transfer between the windings too?