How does Lord Kelvin's water drop electrostatic generator work?

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SUMMARY

The discussion centers on the operation of Lord Kelvin's water drop electrostatic generator, specifically the mechanisms behind the generation of high voltage potential. The user proposes two hypotheses: one involving the role of ions in the water influenced by the apparatus's rings, and another considering the potential difference due to gravitational effects, estimating approximately 100V per meter. The generator features a 1.5cm spark gap that discharges every 10 to 15 seconds, suggesting the generation of thousands of volts. The user seeks insights into how such a significant potential difference accumulates rapidly.

PREREQUISITES
  • Understanding of electrostatics and electric potential
  • Familiarity with the principles of ionization in liquids
  • Knowledge of gravitational potential energy and its effects on charged particles
  • Basic concepts of spark gaps and discharge mechanisms
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  • Research the principles of electrostatic generators, focusing on the Kelvin water dropper
  • Explore the effects of ion concentration in water on electrical conductivity
  • Investigate the relationship between gravitational potential and electric charge in fluids
  • Learn about the physics of spark gaps and their role in high-voltage applications
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Students, educators, and hobbyists interested in electrostatics, physics demonstrations, and the workings of electrostatic generators will find this discussion beneficial.

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I recently made a small version of Lord Kelvin's "thunderstorm" while I was bored at school one day, and I'm still mystified as to how such a large potential gets generated. I have two hypotheses, but I haven't had a chance to test them yet and I was wondering if anybody knew how the generator works.

My first hypothesis was that perhaps ions in the water are pushed and pulled by the rings attached to the buckets and it is the ions that provide the potential difference. This seems improbable, but I was going to test the apparatus with deionized water just to see.

My other hypothesis takes into account the potential difference that exists between the lower buckets and the water source above it. I remember reading in Feynman's lectures a while ago that there exists about a 100V potential difference for every meter above the Earth (assuming flat ground with dry air or lots of ions present like above the ocean). Could the water actually be carrying this charge difference down with it? The water source is only half a meter (if that) above the lower buckets.

The apparatus has a 1.5cm spark gap made of tin foil that discharges every 10 or 15 seconds while its running. I haven't done the calculation, but I'm guessing this is on the order of magnitude of thousands of volts. Any ideas on how such a large potential difference builds up so quickly?
 
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Is there something in http://en.wikipedia.org/wiki/Kelvin_water_dropper" that you want further clarification for?
 
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