its a dirt devil dynamite, its been doing this since it was bought, and its probably been run about 5 hours now without a cleaning and still building up charge. yes, rather dry, i am in arizona after all. however, its done it with a high humidity as well, just not as much buildup.
taking a closer look at what was going on, i first noticed that brining my finger near the outside as it was running would cause a build up of hair and dust on the inside in that spot, before the buildup got too large, and was whisked away by the spinning air. upon opening it up, theres an obvious static field on the inside and out, and filling it with water with teh inside coated with dust with the lights off, i could be wrong, but it appears that some of the discharges were taking place THROUGH the plastic. i think now that part of the effect is a charge seperation going on, but im not sure. i dont really have the tools to test this. im thinking of making a charge detectors as seen on bills website, but i think id have to really drop the sensitivity. (as an aside, hey bill, does that thing notice wires with juice running through them? id had a daydreamish thought of building a glove, the bottom side covered with wires, the leds on the top directly above, and have it set up so you could wave your hand over the wall and see the wires. be really usefull for drilling into walls and that. anyways) if thats the case, then in part the plastic is acting like a seperator in a capacitor. also,thought was that it may be that the brush against the carpet is building up a charge, and thats being transfered to the body of the vacumm due to lack of grounding, but it builds up charge on a dusty tile floor as well, and no difference qualitatively between different kinds of carpet/fabric. but again, i have nothing to test that quantitaviley, other than measuring time before the static can be felt at a certain distance from the cylinder, and that still relies on a bit of subjective data. also, since im sure it will be asked, ive vacummed up an area, completly discharged inside and out with my hand, poured the dust back over that area of carpet, and vacuumed again. identical build up of charge. i might also note, the handle is an aluminum tube, covered in 1/4 plastic, snap together, no metal screws to carry charge. im being shocked THROUGH the plastic handle, its less painful than your average heavy door knob shock, but obviously more powerful (had a muscle spasm in my hand with one of them, felt like the time i was 5 and stuck a safety pin into one blade of an outlet. ) richard, what kind of details are you looking for? On 4/30/05, William Beaty <[EMAIL PROTECTED]> wrote: > On Sat, 30 Apr 2005, Michael Foster wrote: > > > > > What brand is the vac? I gotta try this. > > Very cool! A low-humidity environment is probably the key to this. > > Powder impact on plastic should charge both the powder and the plastic. > I've never seen it happen with my vacuum in Seattle, so it might be our > humid weather rather than the particular brand of device. > > Also, a bit of greasy salty filth can make a surface too conductive. Or a > microscopic bit of oil on the plastic can coat the dust and halt the > charging (this is how "clothes dryer sheets" eliminate static cling.) A > brand new vaccum cleaner might create vicious sparks, but after a few > hours of operation the sparks would stop again, unless the plastic > interior was thorougly flushed with soapy water, alcohol, etc. I've > noticed that, while cleaning plastic to create electrostatic effects, you > have to *flush the surface* with a stream of liquid. If instead you scrub > with alcohol-soaked paper towels, the surface remains contaminated. > > (((((((((((((((((( ( ( ( ( (O) ) ) ) ) ))))))))))))))))))) > William J. Beaty SCIENCE HOBBYIST website > billb at amasci com http://amasci.com > EE/programmer/sci-exhibits amateur science, hobby projects, sci fair > Seattle, WA 206-789-0775 unusual phenomena, tesla coils, weird sci > > -- "Monsieur l'abb�, I detest what you write, but I would give my life to make it possible for you to continue to write" Voltaire
