[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Early TC's w/o topload



Original poster: "D.C. Cox" <resonance@xxxxxxxxxx>



The first toploads of toroids were used by Tesla for field control to prevent his barn like structure (wood) from burning down where the HV exited up the tower.

I first saw them used by the Germans for resonance transformer field control in a Physical Review article and also a book in the late 1940's right after WWII.

I copied this idea and started using them actively in 1966 along with large spheres and oblates. Wysock also started using them after reading the German article but he wasn't an active coil builder until the 1970s and 80s. I first saw his in operation in 1981.

All of this of course pre-dated the Tesla List and internet by over 30 years.

Dr. Resonance


Original poster: Steve Conner <steve@xxxxxxxxxxxx>


Nowadays, everyone uses a "toroid" as a "topload" on their coil(s).  I
believe the term "topload" is credited to the good folks on this Tesla
List.

I don't know "who" first called it a "topload" but I believe I know the reason for using that name. In radio engineering you often see reference to "top-loaded" antennas. These have a plate or network of wires attached to the top of the mast to add capacitance and allow a shorter antenna mast to be used. The top-loading capacitor is sometimes referred to as a topload. Some antennas also have a loading inductor at the bottom or in the middle.

Now, the analogy to a Tesla coil seems pretty obvious to me. A Tesla coil is just a short vertical antenna with a loading inductor at the bottom and a loading capacitance on top, and the antenna mast in between is then made shorter and shorter until it's completely gone. It is now near useless as an antenna and radiates practically nothing. Instead the input power piles up in the resonator before bursting out in the form of enormous voltages and colossal discharges.

If you think of the coil as a modified radio antenna, "topload" is the natural name for whatever you place on top.

Steve Conner
http://www.scopeboy.com/