Science calculator

Transformer ratios.

Solve voltage and turns ratio, or primary and secondary current using ideal power conservation. Enter three values and leave one blank.

Relationship

Primary voltage Vₚ

Secondary voltage Vₛ

Primary turns Nₚ

Secondary turns Nₛ

Secondary voltage VₛSolved

—

Vₚ / Vₛ = Nₚ / Nₛ

Ideal transferred power: —

Display precision

\frac{V_{p}}{V_{s}} = \frac{N_{p}}{N_{s}}

V_{p} I_{p} = V_{s} I_{s}

Vₚ, Vₛ RMS voltages · Nₚ, Nₛ turns · Iₚ, Iₛ RMS currents

Assumptions

Ideal transformer: perfect magnetic coupling, no winding resistance, leakage, core loss or magnetising current.
Sinusoidal AC steady state; voltages and currents are consistent RMS values.
Turns are positive and the core is not saturated.
An ideal transformer does not operate from steady DC; real output power is lower than input power.

How it works

The induced voltage per turn is the same in both windings, so voltage ratio equals turns ratio. More secondary turns step voltage up; fewer step it down.

With no losses, input and output powers are equal. Current therefore changes inversely with voltage so VₚIₚ = VₛIₛ.

Leave one value blank to rearrange the selected ideal relationship. Use a measured efficiency calculation for a real transformer rather than treating this result as a guaranteed rating.

Free
No ads
No tracking
No account
Works offline once loaded

From the maker of Ans — a scientific calculator you can own. Same idea: a proper instrument, nothing in the way.