How to power the Jacobs Ladder


                                                                               Figure 2:  Boiler
Power Supply

<>The most difficult part in building a Jacobs ladder is obtaining a high voltage power supply. If you happen to live where the primary heating source of your home is an oil fired boiler this becomes a relative simple task. The boiler uses a step-up transformer to change the nominal 120 volts supplied by your house wiring to around 10,000 volts. It is important to remember that this is the RMS voltage and the peak voltage of this transformer is around 14,000 volts. These transformers usually are internally fused to limit the maximum current to around 30 milliamps. This current is potential large enough to be fatal so exercise caution while using it.  It just so happens that 10,000 volts is a good starting point for a simple Jacobs’s ladder.

Another word of guidance is if you happen to use the transformer off your parent’s boiler it would be a good idea to put it back before they can find out about it. Parents have a tendency to not understand the importance of using any equipment available for experiments. It probably did not help that I forgot I had taken it off one night and ended up getting a call the next morning in class that I was a mad scientist and I needed to get the boiler running ASAP. Apparently the temperature in our house had dropped about 10 degrees Fahrenheit. Oh well, my parents have become well adjusted to expect such things from me.
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Alright now that we have discovered the power source, the job at task is to remove it from the boiler. Before we go any further with this I must warn you that this high voltage transformer is very dangerous and a few safety considerations need to be implemented. Boilers are required by code to have a disconnecting device with in sight. As this is not a perfect world in older instillations the wiring is generally a mess. Therefore it is recommended that you turn off the switch in front of the boiler as well as the circuit breaker that is located in the main panel of your house. Once this has been done the power supply can be started to be removed. The following sequence of pictures shows this. 

Figure 3:  Power  Supply Removal
Once the screws have been removed the transformer should sit on a hinge and it can be rotated upward.  As a safety precaution the load contacts on the transformer should be short circuited with an insulated screw driver.  This is a last resort effort to make sure the circuit providing power to the transformer is turned off. If for some reason it was still turned on there would be some arcing occurring across the screwdriver and the output terminals of the transformer. Please make sure the circuit is turned off so that this does not happen.



Figure 4:  Discharging contacts

There are a few wire nuts that maintain an electrical connection to the supply side of the transformer that will have to be removed. Just twist off the wire nuts and pull the connections apart. A word of advice, draw a diagram for the connections if you have never done this before. Other wise when you go back to reconnect it you will most likely have forgotten what hooked up to where.

 
Figure 5: Wire Connections

Finally there should just be a couple of bolts to remove and the transformer can be taken off the boiler. Then you are off to the building stage of the Jacobs Ladder.

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