Hi Neville, I don't think you've got DC theory down yet and AC theory is already rearing it's ugly head for you.
Safety first, though. 240VAC (that is, Volts [of] Alternating Current) is deadly; I was taught the "One hand in your pocket" rule regarding ANY high voltage. This tends to reduce the chance of passing electric current from one hand to the other through the heart; glad your mom survived! So; on to the mythical 24 volts DC from a wall-wart; Alternating Current is electricity that varies in a smooth (we hope) manner, over time, 50 or 60 times per second, with the voltage pushing it rising to a maximum value which is about 1.4 times "higher" than the "stated" value of, for instance, a positive 120 Volts, then sinking in value through 0 Volts, then proceeding smoothly until a minimum (i.e. maximum negative) value of about 1.4 times negative 120 Volts, returning through 0 volts again and so on. there is a difference of 240 volts electrical potential between the greatest positive "ROOT-MEAN-SQUARE" value and the greatest negative "RMS" value. Why the confusion factor of 1.4 times? (RMS?)? Aahhh, AC theory, that's why! If you were to simply use a Direct Current value of 240 volts (240VDC) between the "supply" and "return" electric lines there would be quite a bit more power available in the lines than there is when the AC voltage is at less than it's maximum positive or negative value for significant parts of the alternating cycle. To compensate - more or less [Bad pun, Bad!]- for this the electrical engineering wizards in their infinite mathematical wizardry calculated that upping the ante to 1.414141... times the nominal value for AC would give the same power carrying capacity that a DC supply at that nominal value would exhibit; simple, no? No. But there you are. There are some weird consequences to this hokey-pokey, one being that your "24"VDC wall-wart can yield about 1.4 times its "nominal" voltage when it is very lightly loaded. More fun; Malcolm On Sat, 2008-09-06 at 22:33 +0930, Neville wrote: > ----- Original Message ----- > From: "Wayne Fugitt" <[email protected]> > To: <[email protected]> > Sent: Saturday, September 06, 2008 8:26 PM > Subject: CS>LED's, What Voltage ? How Dangerous ? > > > Morning Wayne, > > Not sure if you are directing this at me? > > Just in case you are I would like to say that the although the adaptor I am > using plugs in to 240 Volt mains supply, (our mains power supply is 240 V), > it is 24Volt DC output. Not sure if you are thinking I am using 24 volt AC > MAINS SUPPLY power on my CS generator, as that is NOT the case, it runs on > DC not AC. > > I can also remember when I was 3 or 4 years old, (long before school), my > mother screamed from the laundry and as I walked in to see her she told me > to get out, rather abruptly, (I thought I had done something wrong you see, > and as it happened I almost DID), I can still see here in my minds eye today > getting the strength up to rip her clenched hand off the top of the agitator > on the old washing machine and after doing so immediately lying down on a > bed. To this day I will never understand how she managed to remain alive, > considering the time lapse spoken of here, and ripping her clenched hand > free from the machine due to the electricity acting on the muscles in her > fingers, and not being killed, (one tough SOB I guess). When I was older > she told me that she yelled at me because she knew I would touch her and > then I would get it also. From this I always approach electricity with the > back of my hand as if it is live I won't grasp whatever it is I touch...she > taught me that. -- The Silver List is a moderated forum for discussing Colloidal Silver. Instructions for unsubscribing are posted at: http://silverlist.org To post, address your message to: [email protected] Address Off-Topic messages to: [email protected] The Silver List and Off Topic List archives are currently down... List maintainer: Mike Devour <[email protected]>
