Transformers have been in use since the 1830s, but they have greatly evolved since. Most transformers you see are at electrical facilities or on phone poles. Using a few basic tools, it is possible to build your own transformer.
Drill two holes in each piece of flat bar for the bolts. The holes should be near the ends of all of the bars.
Wrap the two longer bars with a thin layer of electrically insulated tape.
Wrap each of the longer bars with the magnet wire after putting on the layer of tape. Do this by making several hundred turns around each of the bars. To start with, you should use equal lengths of wire around the bars. Later, you can use differing lengths so the transformer can step voltage up or down.
Connect the two bars together using the two smaller bars of steel. The transformer should now be a rectangular shape. Use the bolts, nuts and washers to hold the bars together.
Use the ohm meter to check for shorted windings. Check for continuity between the steel bars and the winding. Also check for continuity between the winding ends to make sure no part of the wire is broken open. If there is a problem with the measurements, you must unwrap the wire and try again.
Connect the low voltage power supply to the wires on your transformer. Your power supply should be something like the power supply that can be viewed by clicking "Supply" below. You should not try to power your transformer from a wall socket. This is far too much voltage and very dangerous.