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New regulated Power Supply

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Hi,

I just picked up a new DC regualted power supply (0-12v at 1.5A) and i was wondering if these voltages/currents could potentially kill me.

I couldnt really understand the wikepedia explanation (https://en.wikipedia.org/wiki/Electric_shock#Avoiding_danger_of_shock) and Ive searched the forum but i couldnt find a clear answer.

1.5A could certainly kill you. 30mA or less in the right place (your heart) can kill you. But human skin is pretty resistive, so it takes higher voltage than 12V to push that much juice across your chest, unless you plunge the electrodes through your ribcage. :)

So 1.5A can be dangerous, but shock hazard is very low at 12V unless you're covered in salty water or something.

If the power supply runs off the mains, then there are voltages inside the supply which could hurt or kill you, though--but I guess you know that.

So you should be OK. Just respect electricity in general. It's easy to screw up. :) If I was confident that the voltage was 12V, I'd feel OK holding the contacts with dry hands. At 120V, no way. I wouldn't touch either to my tongue.


Torben
 
The only thing I could add to Torben's comments - however unlikely, it is possible for mains voltage to appear at the output as a result of a fault in transformer or wiring.

Another issue - 1.5 amps could cause a conductor to heat sufficiently to burn you or start a fire. I recall being burned by a fine wire that got hot - wasn't much current but illustrated the point that reasonable care is always required.
 
I can tell you that there are several websites that go into this with lots of detail - but I can't recall the websites (sorry) nor the specifics. I can say that the connection from the source to your body plays a very critical role. Dry skin and light contact with something that is energized presents a very high resistance therefore relatively low current flows. Wet the skin - or taking it to the extreme - inserting needles profoundly reduces the resistance allowing for relatively low voltages to result in relatively substantial current flow.

Again - what you are looking for is nicely documented.
 
Generally the sources i have looked at all quote current limits with some sources different to others!
I have an idea but I just wanted to confirm.

Thanks for the replies.
 
current is the real culprit but high voltage can give painfull shock. i doubt that with low current it can kill you. but torben did specif the limits though.
 
current is the real culprit but high voltage can give painfull shock. i doubt that with low current it can kill you. but torben did specif the limits though.

Actually, no, I didn't. :) Re-read my post.


Torben
 
The voltage has to exceed about 60VDC before it stands any real chance of killing you, even 120VDC is relatively safe (much safey than 120VAC 60Hz) , although it it shock hazard so don't touch it!
 
voltages/currents could potentially kill me.
In the whole history of the U.S. Navy, only one person got electrocuted on a voltage as low as 47 V.
Also, dumping electrical energy of > 1 joule into someone may kill. Supposedly modern day car ignition coils store and discharge this kind of energy level.
 
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In the whole history of the U.S. Navy, only one person got electrocuted on a voltage as low as 47 V.
That was probably because he was covered with salt water and had a cut on both of his hands.

I don't know about he US regulations but the UK regulations reduce the maximum voltage on exposed accessible conductors from 60VDC to 30VDC in wet areas, presumably to stop this kind of thing from happening.
 
Thanks.
Im feeling less apprehensive about my 12v supply now.
I dont think ill ever need a suppy greater than 20v so im sleeping better knowing my hobby wont end my life :)
 
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