On 2014-10-25 17:19, Lew Wolfgang wrote:
On 10/25/2014 07:49 AM, Patrick Shanahan wrote: ellanios82 <> [10-25-14 10:41]:
re : "makes me VERY nervous when replacing them" . . . would reason be risk of electric shock? more likely burn. One is very unlikely to get "shock" from dc current, but availability of instantaneous high current greatly increases burn hazard.
I respectfully disagree! Direct current is even more dangerous than alternating because the DC will "freeze" your muscles which could
Yes, but we are talking of 12 volts here. I can hold the rods of a 12 volt battery, even a huge one, and I don't even notice it in my fingers - provided they are not wet. Yes, I have done it, so I do know. Other people are more sensitive. About the burn: yes, but not your body, for the same reason as above. If you short-circuit the connecting rods or plugs, then indeed you have burn danger. You can even melt the metal doing the short circuit, in a explosion if the battery is big enough. It is similar to an arc soldering device: you can do it with a battery, but you risk destroying it. If your hands are wet, or worse, humid with sea water, or battery acid, then you do risk some electrocution danger. Depends where you touch it. The wrong place and method and even a torch battery can kill you (passing the current through the heart with a good connection).
from walls and ceilings make it easy to differentiate. What was amazing is this guy was in his late '50s and hadn't figured all this out for himself!
Because not everybody has a good ear :-) I have seen somebody navigate a big room full of obstacles, just using tongue clicks. I think he even tried with a bicycle, blind, in a parking lot. -- Cheers / Saludos, Carlos E. R. (from 13.1 x86_64 "Bottle" at Telcontar)