How to Build a Simple Electrical Transformer for School


A transformer is an electrical device that can be used for one of two functions. The first function of a transformer is to isolate one side of an electrical circuit from direct current electrical energy. Since a transformer works by converting electrical energy into a dynamic electromagnetic field, only alternating current will pass through a transformer. A transformer can also be used to change the voltage of an input AC signal. If the number of windings (also known as "wire turns") around a transformer core is greater at one side of the transformer than the other, the voltage will increase or decrease according to the proportion of wire turns. Many transformers use an iron or nickel core. A simple transformer can be constructed using insulated electrical wire wrapped around a common core.

Things You'll Need

  • Insulated electrical wire (12" long)
  • Electrical pliers
  • Iron rod (such as a small piece of construction rebar)
  • Permanent marker
  • Use the electrical pliers to cut the wire at the halfway point between the two wire ends. Strip half an inch off of the ends of both wire segments.

  • Wind the first wire segment around the top of the iron rod, leaving approximately two inches of slack at each end of the wire segment. Color the insulating material at the ends of this wire segment with the marker tip.

  • Wind the first wire segment around the top of the iron rod, leaving approximately two inches of slack at each end of the wire segment.

  • To use this isolation transformer, connect the AC power source to the colored wire leads, which serve as the transformer primary. Connect the output device to the other wire leads (the transformer secondary).


  • Photo Credit transformateur électrique image by Lounatiq from
Promoted By Zergnet


You May Also Like

  • How to Build a Transformer

    Transformers have been in use since the 1830s, but they have greatly evolved since. Most transformers you see are at electrical facilities...

  • How to Make an Electrical Step-Up Transformer

    Transformers change the current and voltage passing from one circuit to another. The transformer includes a magnetizable material, called a "core," that...

  • How to Build a Simple Transformer Coil

    A transformer, a device in which a magnetic field couples two circuits while linked to each, converts one AC voltage to another....

  • Homemade Electrical Transformers

    An electrical transformer changes the current and voltage levels in an alternating circuit using magnetic induction. You can make a homemade transformer...

Related Searches

Check It Out

How to Build and Grow a Salad Garden On Your Balcony

Is DIY in your DNA? Become part of our maker community.
Submit Your Work!