Hi,
This might help a little too...
The transformer turns ratio usually refers to what the transformer
does in terms of voltage. For example, if you have 120vac in and
12vac out, the turns ratio is said to be either 10 or 1/10.
If we call it 1/10 then TR=0.1 and the output voltage is TR*Vin
or 120*0.1=12v output.
For the current, it's the inverse, so if we call the turns ratio 0.1
again then the CURRENT ratio is actually 1/TR=10, so if we have
0.1 amps ac input then we can get 0.1*(1/TR)=0.1*10=1 amps output.
We might call the 0.1 turns ratio the FORWARD turns ratio, while
10 we would call the REVERSE turns ratio, and this refers to voltage
unless otherwise indicated. This makes it easy to calculate the current
ratio, which is then simply 1/TR.
Another example:
We have 120vac input and 10vac output. The forward turns ratio
is TR=10/120=1/12=0.083333, while the current ratio is 1/TR=12.
This means with 0.1 amps input we can get 1.2 amps output.
If we were to use the transformer in reverse, we could put in 1.2 amps
and get 0.1 amps output. This is how many current transformers
operate.