# Transformer voltage variation from no-load to load operation

- Author:
- Mauro Andriollo

Moving the slider load impedance power factor is changed. You can easily appreciate the difference between VOLTAGE VARIATION (difference between the length of the phasor (primary supply voltage) and the length of the phasor (secondary voltage referred to primary)) and the VOLTAGE (or IMPEDANCE) DROP corresponding to the voltage drop on the short circuit impedance .
Plase note the colour change of the segment related to the voltage variation when . Note also the difference between (phase displacement between and ) and (phase displacement between and ).
The angle colour changing passing from lagging to leading phase displacement.