I came across an interesting reference. It appears that charge flow is both directions. See http://www.ee.ic.ac.uk/eee2proj/rtal97/physics.html especially Figure 5 at the bottom of the webpage.
> ---------- > From: Lichtenstein, Ross[SMTP:[email protected]] > Reply To: Lichtenstein, Ross > Sent: Thursday, October 05, 2000 10:54 AM > To: 'Barry Ma'; [email protected] > Subject: RE: Electron Flow > > > Barry, > > I could be wrong, and if so I would stand corrected, but from my basic > electronics training, > I recall that electron flow is from negative to positive. > > I also recall being taught that lightning actually travels from earth > (neg. > charge) upward > to the positive charge of the clouds. Then there is also the case of > lightning between clouds > of opposite charge, and again the electron flow direction is from neg. to > pos. > > Ross > > -----Original Message----- > From: Barry Ma [mailto:[email protected]] > Sent: Wednesday, October 04, 2000 5:58 PM > To: [email protected] > Subject: Re: ESD Opportunities > > > > Please allow me to ask a relevant question only for curiosity. > > We have no idea of what charge (positive or negative) would go to the DUT > in > ordinary ESD. > That's why we have to test two polarities in ESD immunity test. > > Lightning is a kind of ESD happened between a charged cloud and objects on > earth surface. Some figures imply that an electron current flows from the > charged cloud to the earth. Is it possible to have an opposite direction - > electron flows from earth to cloud? > > Thanks. > Barry Ma > > _______________________________________________________________________ > > Free Unlimited Internet Access! Try it now! > http://www.zdnet.com/downloads/altavista/index.html > > _______________________________________________________________________ > > > ------------------------------------------- > This message is from the IEEE EMC Society Product Safety > Technical Committee emc-pstc discussion list. > > To cancel your subscription, send mail to: > [email protected] > with the single line: > unsubscribe emc-pstc > > For help, send mail to the list administrators: > Jim Bacher: [email protected] > Michael Garretson: [email protected] > > For policy questions, send mail to: > Richard Nute: [email protected] > > > ------------------------------------------- > This message is from the IEEE EMC Society Product Safety > Technical Committee emc-pstc discussion list. > > To cancel your subscription, send mail to: > [email protected] > with the single line: > unsubscribe emc-pstc > > For help, send mail to the list administrators: > Jim Bacher: [email protected] > Michael Garretson: [email protected] > > For policy questions, send mail to: > Richard Nute: [email protected] > > ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: [email protected] with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: [email protected] Michael Garretson: [email protected] For policy questions, send mail to: Richard Nute: [email protected]
