boberic Loc: Quiet Corner, Connecticut. Ex long Islander

True story about electrocution. In the City of NY at the ME's off ice on 1'st and 30th there is a forensic pathology museum, where the specimens are kept. They descovered a dead man on the subway tracks. He had electrocution burns on his penis. They couldn't understand why someone would touch his penis to the third rail and thereby comit suicide (third rail voltage is 100 volts DC and is extremely dangerous). Turns out he pissed on the third rail and it arced and killed him.

pounder35 Loc: "Southeast of Disorder"

I've been "bit" several times by flash capacitors. 330v but a quick discharge. It'll make you use words your mother would not like to hear.

flathead27ford Loc: Colorado, North of Greeley

Jerry, just don't burn your home down. We like seeing you here. :-) Cheers.

whitewolfowner

Volts do not kill you; amps do.

whitewolfowner

Jerry, wood holds in heat, the worst thing you can do for shortening the life of those drives. You will need quite a fan and openings to keep the heat dissipated; then you have to be weary of dirt, and depending on where you live; that is a bad killer of drives too. In all honestly, you'd be better getting a manufactured box that has all that stuff worked out for the best; just get one from a good company that posts the specs for it so you know what you are getting.

TriX Loc: Raleigh, NC

They are directly related. More voltage (into the same load) = more current. Twice the voltage = twice the current = 4x the power dissipated.

boberic Loc: Quiet Corner, Connecticut. Ex long Islander

Volts and amps dont't exist untill the switch is ON for a certain amount of time. Therefore ONLY energy (joules) kills.

TriX Loc: Raleigh, NC

Correct. In practical terms, the voltage needs to be high enough, given the body's internal and skin resistance (and the current path through the body) to cause adequate current to flow (for long enough) to be fatal. Because of that, all other things being equal, the danger rises with the voltage, and in general, because of the danger of cardiac fibrillation, AC can be more dangerous than DC.

whitewolfowner

They are and they are not. Increasing one does not increase the other; each can be totally controlled independently from the other. Think of electricity as a garden hose and the voltage the size of the hose and the current (amps) is how fast the water is flowing.

TriX Loc: Raleigh, NC

E=IR (or I=E/R) and P=IE. can't get any more basic than that. For a given resistance (R), increasing the voltage increases the current, and the power is the product of the voltage x current. For a FIXED resistance load, changing the voltage ALWAYS changes the current. Ohm's law... By way of your water analogy, think of voltage as the water pressure, resistance is the hose diameter, and the current as the amount of flow.

whitewolfowner

Your math only works if you don't change the electronic components you are putting the charge through; then of course you could blow the circuit or fry the parts too. Voltage and current can be totally controlled. Look on all those power supplies you have fro all the electronic parts you have on the house and read the voltage and currents they deliver; they will all be different in one way or another. I am in engineering in this with a degree and know what I am talking about. Have you ever heard of resistors, diodes, capacitors, inductors, transistors and all the other circuit parts; what do you think they do?

TriX Loc: Raleigh, NC

That is exactly what I said: if the load resistance remains unchanged, then increasing the voltage increases the current - period - no exceptions to Ohm's law. If you're referring to controlling voltage or current independently from power supplies, think about how you limit current or voltage - using a series pass transistor which is essentially a variable resistor in series with the load, or the current is limited by the internal resistance of the supply (which is again, a resistor in series with the load)

I am actually an engineer, have been in electronics for 60 years (including power design for major companies), been a military electronics/computer instructor, have held an amateur extra class license (and build my own HF amps and power supplies) for 25 years, and design power supplies and amplifiers for a living (you're welcome to visit my site), so with reapect, there's nothing you can teach me about electronics. Do yourself a favor and don't embarrass yourself by denying Ohm's law in public.

whitewolfowner

Toushee, don't pad your own ass and think you are the only one who knows electronics. You are the one stepped on your own dick responding to me as you did. It's called hiding your ignorance, my friend.

n3eg Loc: West coast USA

Those lighted switches are loads of fun to wire correctly, even with 12 vdc. Takes a little more thought than usual.

TriX Loc: Raleigh, NC

I certainly don't think that I'm the only person on UHH who knows electronics - in fact, there are many here and several other EEs and extra class holders. I have responded to you with the most basic facts of electricity, Ohm's law.
So what part of my statement(s) do you specifically disagree with?

Reading your post again, you seem to be referring to the voltages and currents from various "wall wart" power supplies. These are simple supplies, typically consisting of a transformer, a bridge rectifier and a filter capacitor. They rarely have a voltage regulator (but may). The output voltage is determined by the secondary voltage of the transformer and the load. The current rating is typically the maximum current that can be supplied at the rated voltage. The actual current depends on the load resistance AND the internal resistance of the transformer secondary - they appear in series. If you want to prove Ohm's law to yourself, get out a "wall wart" (unregulated) supply, your DVM and a handful of resistors, and start loading the supply with different values. You can then monitor the voltage and current and easily calculate the internal resistance of the supply. You'll notice that as you increase the load (decrease the resistance), the voltage will drop and the current will rise, exactly as predicted by Ohm's law.