Cable Asylum Interconnects, speaker wire, power cords. Ask the Cable Guys.

---

[ Follow Ups ] Thread: [ Display  All  Email ] [ Cable Asylum ]

---

[ Alert Moderator ]

---

Re: Current is more dangerous

Posted by rp1@surfnetusa.com (A) on June 17, 2003 at 13:09:31

In Reply to: Current is more dangerous posted by Zozo on June 17, 2003 at 05:32:11:

Your previous post was very gracious Zozzo. It is easy to get the actual use of Ohms/Watts law confused if your original premise is flawed. (I know, done it many times!) And the laws assume an infinitly small power-supply impedance; that is, unlimitied current availablility. Which is not the case for power-supplies and batteries. Of course, as far as us getting our butts fried it is practically true with house wiring!

I remember when I was working in a hospital, we would test any appliance (radio etc) that was brought in to a patient for leakage. Anything with a leakage of over 50 micro-amps was rejected. It seems that 50 micro-amps under the skin was usually fatal. Hospitals here no longer allow any consumer electronics in to a patient with implanted probes, IV's, or the like.

Higher voltage tends to be more lethal because, again, it makes it easier to shove a given amount of current through the skin. ( I remember a guy that used to test for voltage with his fingers; he could tell the difference between 110, 240, and 440vac. Too bad he ran into 880 one day... His widow said he was always an idiot.)

Your car battery has a ton of current but people are seldom killed by it (has happened a few times though under strange circumstances) because 12 volts is not normally enough to get through the skin's resistance. Once below the skin though and it kills just as well as any other source.

I think we settled on 120vac nominal because of a combination of safety and expense issues. I recall that there was a great argument between Edison and Tesla/Westinghouse over the relative safety of the low-voltage dc versus high-voltage ac. I think the resulting voltage was a compromise. Also I don't think they were excpecting so many high-power consumption devices to be used in the home. Tho, thinking about it, everything about running 220vac nominal to a house is cheaper than our way of doing it; all wire insulation is rated at a minimum of 600volts anyway so being able to put thinner wire all through a house has got to be cheaper. Plugs and switches are also cheaper. Amplifier transformers can be cheaper and/or more powerful. Darn.....we got screwed. Anybody have the UK wiring code handy?

This post is made possible by the generous support of people like you and our sponsors:

Antique Electronic Supply

---

[ Top of Page ] [ Contact Us ] [ Support/Wish List ] [ Copyright © 2013, Audio Asylum, all rights reserved ] [ Take5 ]

---

[ General ] [ Speakers ] [ Tubes ] [ Vinyl ] [ Digital ] [ Hi-Rez ] [ Video Asylum ] [ Cables ] [ Tweaks/DIY ] [ Music ] [ Films ]

---