Building the Jacobs Ladder

The building process of a Jacobs’s ladder is fairly straight forward and there are many different ways of doing it. The main equipment consisted of the following: 1x6 inch piece of wood, #4 AWG bare solid copper, #12 AWG type XHHW copper wire, 15 amp 120 volt male plug, a few wire nuts, and an extension cord. All of the copper wire can most likely be scrounged from an electrician. The male cord can be purchased from any local supply house for a few dollars. I just happened to have this stuff sitting around my house so it did not take me long to shop for everything. The following picture shows most of the equipment used in this experiment.

Figure 7: Ladder equipment

The 1x6 inch piece of wood I bored 2 quarter inch holes a half inch in depth and width apart. The main ladder conductor was the #4 AWG solid copper which was cut into 3 feet lengths and shaped straightly as possible. The ladder conductors were then placed into the wood. The holes drilled were just large enough so that the conductors would remain in their respective holes with out falling out. The ladder conductors were then pulled apart at the top of the ladder so that there was a 1 inch gap across the top. This made the geometry look like a narrow V. The very top of of the ladder conductors were bent out away from each other. Then the #12 XHHW wire was cut into to pieces of 1.5 feet in length and both ends were stripped. Each end was then curled around an individual ladder conductor and the other set of ends was connected to the output terminals of the transformer. Bear in mind that the insulation for the #12 XHHW wire is only rated up to 600 volts and the transformer is operating around 10,000 volts. Therefore it is recommended to use a cable that is rated for a much higher voltage to connect the transformer to the ladder electrodes. One could use some coaxial cable (cable TV wire) which is not necessarily rated for high voltages but it is basically manufactured the same way as high voltage cable. It has a thick dielectric layer around a central conductor with a shield wrapped around the dielectric. This is a cheap alternative to buying high voltage cable. The male plug was then connected two short chunks of #12 XHHW wire and the other ends were connected to the line side of the transformer with wire nuts.

Figure 8: Electrode Connections

Figure 9: Equipment Set Up

Once the equipment was set up the ladder was ready for testing.