5K30.20 Dissectible Transformer


Magnetic induction, transformers


This is a transformer with swappable secondary coils, which all step down from the wall outlet 120 VRMS.



  • [1] Dissectible transformer with 800-turn primary coil
  • [1] 40-turn coil
  • [1] 80-turn coil
  • [1] 200-turn coil
  • [1] Multimeter & leads

Classroom Assembly

  1. Assemble the transformer with the desired secondary coil.
  2. Attach the multimeter to the secondary coil.
  3. Set the multimeter to AC volts at an appropriate scale.

Important Notes

  • Some of the secondary coils are hard to attach to and remove from the iron core. Try not to hurt yourself doing this.


  1. Turn on the multimeter.
  2. Plug in the transformer.
  3. Note the voltage across the secondary coil.
  4. Change the secondary coil and repeat 1–3 as required.
  5. Unplug the transformer.


Additional Resources


  • PIRA 5K30.20


  • Don't attempt this at home!

Last revised

  • 2019


Related AV

Related demos


If you have any questions about the demos or notes you would like to add to this page, contact Ricky Chu at ricky_chu AT sfu DOT ca.