TK is that your hand getting so close to the Bonetti wheel adjustments? You have courage!
Attached is a pic of the cover of my High Voltage bible. I'm sure there are also other good reads out there, but this is my favorite. Recommendation: don't let a copy escape you.
I tend to favor the simple design of Felici or Sames machines, but have never built one so kudos to you on the Bonetti.
(snip)
Somewhat OT but for the benefit of those seeking EHV from electrostatic machines: Yes, my fingers are imparting the initial slight charge by friction to the disks to get the machine started. There are other ways but this is the simplest way I have discovered. One must know just where to touch, though! I think a beta-particle radioactive source placed in the right spot would also work great for starting the "influence" or induction process. For anyone interested in EVH generation I can strongly recommend the TK-Bonetti design as being superior to other designs such as Pidgeon. I've made a couple of improvements in design so that the machine is capable of more voltage and current output per unit volume than just about any other design. In the attached photo, note the position of the neutral structures and the output combs, as well as the distributed corona. While it may look like the corona is coming from the combs onto the disks, it is actually the other way around: the disks are turning in the direction such that the corona comes off the _disks_ and onto the neutral and output combs. Also, in the area at top and bottom of the disk pair, a very interesting phenomenon occurs _between_ the two disks (barely visible in this photo at the top of the machine). A strange sparkling scintillation happens between the disks in this area between the neutral combs on opposite sides of the disk pair, not corona but something else. The disks are also repelled and attracted to each other in various places around the machine. This makes it difficult to use polycarbonate plastic for the disks, as it is too flexible and the thin disks warp crazily under both electrostatic and aerodynamic loads when in operation. They warp and will crash into each other! So use acrylic plastic which is stiffer. Another thing that is important is that the motors used to drive the disks be "non-cogging" or rather freely turning when not powered. This will allow you to see what happens when you turn the motors off and allow the machine to coast to a stop in a charged state. Very interesting! But don't let your motor shafts and disk hubs be of any conductive material -- the center of the machine is a bad place for anything conductive as the HV will short out across the centers of the disks if it can. The modifications that make the most difference (other than general cleanup and elimination of sharp edges) are the variable positioning of the neutral structures and the output combs. Most builds that you will see of the basic Bonetti design (and in fact all Wimshurst and other rotating disk machines I've seen) actually have the neutral structures and output combs fixed in non-optimum positions; for better performance they need to be made so that they can be moved independently, as in my design. The machine pictured in the attached photo has disks that are approx. 300 mm in diameter and it easily produces 270 mm sparks in rapid sequence between large spherical terminals. Look that up in your spark-gap voltage tables! I enhance the capacitance of my machines by putting a stack of HV doorknob capacitors with barium or strontium titanate dielectric across the output prime conductors. Water-filled Leyden jars work well but are so -- last century! And also wet and sloshy.
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Topic: Using the Earth's vector magnetic potential (Read 95772 times)
