# Transformer ratios with different wire gauges

#### kavkav

Joined Jan 1, 2013
64
Q1. How do you calculate transformer ratios if the primary and secondary have a difference in wire diameter?

Q2. Does it makes sense to use the inductance ratios of the primary and secondary?

Q3. If you are replacing your primary with a thick wire, and you want the ratios of the transformer to remain the same, would it work if the thick replacement wire has the same inductance as the previous primary (with respect the the secondary wire being the same size as the original primary wire) ?

Thanks.

#### crutschow

Joined Mar 14, 2008
34,420
Q1. The wire diameter is not a direct indication of turns ratio. To determine the ratio you can input a known AC voltage and measure the output voltage.

Q2. The relative inductance is also an indicator of turns ratio.

Q3. If it has the same inductance, then it would have the same number of turns. But you may not have room for both windings with the same number of turns if you increase the wire size.

#### kavkav

Joined Jan 1, 2013
64
Q1. The wire diameter is not a direct indication of turns ratio. To determine the ratio you can input a known AC voltage and measure the output voltage.

Q2. The relative inductance is also an indicator of turns ratio.

Q3. If it has the same inductance, then it would have the same number of turns. But you may not have room for both windings with the same number of turns if you increase the wire size.
Understood. Thanks a lot.