> So... I bought one of those positive-ion generators

JT> Negative ion?

 Does it matter?

> (after I'd tried making my own using a Jacob's Ladder of diodes
> right off the mains... a death trap if ever I saw one).

JT> You're supposed to have a 10 meg resistor at the end of it to
JT> prevent shocks if touching the end.

 Chicken...*OF COURSE* I had a limiting resistor! ROFL! It was the
idea of all those diodes and capacitors directly on the mains that
worried me. If one fails, they go one after the other. The Jacob's
ladder falls over.

JT> Stupid thing is, if you DIY, or buy the kit, they give you a
JT> standard garden variety resistor, which arcs over at a couple
JT> of hundred volts.

 I thought a standard resistor was rated at 250 AC. Oh! You mean the
one at the HV end... it's better than nothing.

JT> The theory of operation is that they cause the dust in the air
JT> to clump together (static) which would make the heavy enough to
JT> fall to the floor, where you vacuum them up again, let them
JT> pass straight through the filter and back into the room again.

 It doesn't matter what theory you use (or invent) it's bullshit anyway. 


JT> If you're vacuuming for dust removal, you're fucking kidding
JT> yourself.

 Vacuuming works to some extent. There is a dust filter... in fact,
the new HEPA filters are *very* effective.

JT> We have a dust monitor at work that we occasionally have a
JT> chance to play with when clients don't have it, and we log the
JT> offices overnight. Airborne dust is low, at about 7:30pm, the
JT> cleaners come in with their industrial strength vacuum
JT> cleaners, kick up a dust storm from hell, and it takes the next
JT> four hours for the levels to settle down again. 

 Yair... but if you measure *total* dust before and after, there is
less after vacumming.

JT> If anyone claims their "special" vacuum cleaner stops dust as
JT> well, they're full of shit. Or they have a sub-micron filter
JT> that blocks after 2 minutes of use. After which point your damp
JT> rag would pick up more dust. And it's cheaper. And it uses less
JT> power.

 HEPA filters rely on static. Dyson started the big change, now
they're all doing it. They're still pretty useless...

Regards,
Bob




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