NBC 2009August2

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Electrostim

More electrostim excitement ensued. Once again, driving signal generator output backwards through a transformer extracted from a wall-wart into 3M red dots on our valiant experimenters.

Skin resistance. We tested this after the other tests, and found that the resistance started low and climbed. These numbers are about when we got sick of waiting for it to stabilize. Mikolaj: 55 kOhms, Orion: 50 kOhms, Mike: 116 kOhms, Rachel: 300 kOhms

Results were recorded chronologically. MikeW and Mikolaj observed notable sweating on hands, Orion and Rachel not at all. Also belatedly noticed that symmetry was way skewed to one side until MikeW's second test of second round.

General conclusions: 1mA seems to be a sensible upper bound for current. Next step is to build an inductor-based current source based on standard dc-dc boost topology.

Videos: http://www.youtube.com/watch?v=YRH0xjcnHV4 http://www.youtube.com/watch?v=XSz21QeLd-U

Mikolaj Habryn 15:10, 2 August 2009 (PDT)
Subject V mA f Perception
MikeW 11 0.5 60 initial sensation
MikeW 14 0.6 60 Definitely feel tickle
MikeW 18 0.9 60 muscle contractions (bordering on v. uncomfortable)
MikeW 22 1.2 60 stops being fun
Rachel 6 0.15 60 initial sensation
Rachel 12 0.5 60 can distinguish brief pulses
Rachel 14 0.9 60 distinct buzzing and less precise location sensation when tapping
Rachel 16 1.0 60 muscle twitches in hand
Rachel 18 1.25 60 distinctly uncomfortable
Orion 7 0.2 60 initial sensation
Orion 10 0.5 60 distinct sensation
Orion 15 1.0 60 strong muscular influence
Mikolaj 7 0.2 60 can feel it
Mikolaj 11 0.7 60 sharp tingling sensation
Mikolaj 13.5 0.9 60 pins & needles
Mikolaj 17 1.2 60 can't straighten middle finger. done!
Mikolaj 11.5 0.9 80 slightly more pronounced than at 60 Hz
Mikolaj 13 0.9 120 not huge difference with 80 Hz
Mikolaj 9 0.6 5 feels like 5 Hz tapping
Mikolaj 7 0.4 10 starts to feel like tapping
Mikolaj 12.5 1.0 10 uncomfortable
Mikolaj 11 1.1 7 finger twitches at 7Hz
MikeW 14.6 0.62 60 mild tickle
MikeW 13.4 0.53 60 symmetry fixed initial sensation
MikeW 15.6 0.78 60 distinct sensation
MikeW 16.4 0.92 60 beginning discomfort