A primer on transformers and their use in the electricity distribution grid.
Electromagnets and electromagnetic induction. How transformers work. This is a background information resource that should be used before the jumping ring and boil up demonstrations. It is also useful background for the hydroelectric, wind, and bicycle generator videos. As a stand-alone, it is useful for the level 3 physics curriculum.
This short video provides background for the hydroelectric generator, wind generator, and Bicycle Generator videos.
Transformer demonstrations You can find demonstration transformers in educational equipment catalogues and small transformers are also available at electronics shops. Hook up a signal generator to either coil and a scope or AC voltmeter and ammeters to both coils. Note that transformers are typically designed to work around 50 Hz (mains frequency). Transformers designed for use at high frequency are constructed differently.
Transformers can produce dangerous voltages very easily. Make sure you understand the operation of the transformer and test it before class.
Individual teachers are responsible for safety in their own classes. Even familiar demonstrations should be practised and safety-checked by individual teachers before they are used in a classroom.
Notes, Applications, and Further Reading
The photo shows the first transformer, designed and built by Faraday himself. Faraday’s Transformer is owned by the Royal Institution in the UK. Have a look at their Faraday Museum Page for more information.
The image of Faraday in the video was provided by the Institute of Electrical and Electronics Engineers (IEEE). You can find a lot of useful information about electronic technology and and the history of electronics technology on their website.
This teaching resource was developed by the Te Reo Māori Physics Project with support from
- Te Puni Kōkiri
- The MacDiarmid Institute
- Faculty of Science, Victoria University of Wellington
- School of Chemical and Physical Sciences, Victoria University of Wellington
- The New Zealand map shown on the poster frame above is used with permission from www.nz.com.
- The photographs of electricity grid transformers were provided by Transpower.
- The photos of the generator and transformers at Clyde Dam Power Station were provided by Contact Energy .
- The portrait of Faraday is copyright IEEE, used with permission. The photo of Faraday’s transformer is from the Bridgeman Art Library in the UK.
- The photos of Clyde Dam and Ohaaki Geothermal Field were provided by Dr. Gillian Turner in the School of Chemical and Physical Sciences at Victoria University of Wellington.