School of Physics Lecture Demonstration Manual

Ec-1 Wind Your Own Transformer

Published: Tuesday 14 March 2006 - Updated: Tuesday 29 March 2011


To illustrate the principle of a transformer.



Click on pictures to enlarge.

Transformer Diagram


a) Principle of Physics illustrated 

Faraday's Law of Induction etc.

b) Procedure 

The primary coil is energised with 100V a.c. from the portable variac. A long length of thin wire connected to a 6V bulb is slowly wound around that part of the core which projects from the primary coil. The lamp initially unlit steadily increases in brightness as more turns are added.

Safety notes

Electrical safety 


top of page