Typical person messing with audio is indoors, usually on dry, insulated flooring and surroundings. So issues like moisture and such, don't enter the equation. Indeed, chances of electrocution in such situations is extremely rare as there would be many dead electronic technicians! Industrial or outdoor work is entirely different situation.
As I explained, the factors you mention are not what a person can determine anyway. As such, they are best to stay away from high voltage which I defined as low as 30 volts. Keep in mind that your speaker terminals generate this type of voltage. How many audiophiles you know that have been shocked by that?
I repeat again: any talk about current being more lethal than voltage will lead to opposite and dangerous advice to audiophiles.
They’re both lethal, Amir, clearly. I never said voltage wasn’t important or dangerous. I believe it was you who responded to the omission of this topic in the video by defining your audience as above a remedial level, and what I offered was in that spirit. We all know Ohm’s Law, and it’s clear you can’t have an electrical injury without a combination of both factors. However I see electrical injuries and burns from all causes, not just from capacitors and wires and batteries.
And since this is a scientific forum, I was endeavoring, perhaps hoping—for once—to offer insight on a topic for which
I had specific expertise—in the humble service of enlightening others on here for a change, as I am otherwise a lay person amongst engineers. I realized that it was a tall order, because as much as I admire you and benefit from your startling fund of knowledge about innumerable disciplines in general but my favorite hobby in particular, I have to timidly admit that I have not known you to admit you’re wrong all that much or to apologize easily. So if it won’t steal too much of your sunshine at 1AM on a Tuesday, I’ll offer the following, just in case someone might be interested…
From our gold standard text on electrical injuries:
“Injuries due to electricity occur by three mechanisms:
●Direct effect of
electrical current on body tissues
●Conversion of electrical energy to thermal energy, resulting in deep and superficial burns
●Blunt mechanical injury from lightning strike, muscle contraction, or as a complication of a fall after electrocution
The primary determinant of injury is the amount of current flowing through the body. Clinically, contact with a 120 V circuit carrying a 1 milliampere (mA) current is imperceptible to most persons, 3 mA leads to mild tingling, and 10 to 12 mA leads to pain. One hundred mA directed across the heart can cause ventricular fibrillation. In addition, the voltage, resistance, type of current (AC or DC), the current pathway, and duration of contact all influence the extent of injury.
The tissue damage inflicted by most electrical currents can be primarily attributed to the thermal energy (or heat) generated by the current, as predicted by Joule's law:
Heat = current (I) x voltage (V) x time of contact (t)
= I x V x t
= I x (I x R) x t (from Ohm's Law)
= I2 x R x t
Resistance is a function of the area of contact, pressure applied, and the presence of moisture. Tissues with higher resistance have a tendency to heat up and coagulate, rather than transmit current. Skin, bone, and fat have high resistances, while nerves and blood vessels have lower resistances.
Of all organ systems, the skin has the greatest effect on the severity of an electrical injury. Dry skin has a resistance of approximately 100,000 ohms; however,
this drops to less than 2500 ohms when the skin is dampened. Thus,
in some cases, a lower voltage applied to tissue with low resistance can generate more current and be more damaging than higher voltage applied to tissue with high resistance.
DC current tends to cause a single muscle spasm that throws the victim from the source. This results in a shorter duration of exposure, but a higher likelihood of associated trauma. In contrast, AC repetitively stimulates muscle contraction. Often, the site of exposure is at the hand, and because the flexors of the arm are stronger than the extensors, the victim may actually grasp the source, prolonging the duration of contact and perpetuating tissue injury.
The amount of AC needed to cause injury varies in proportion to its frequency, expressed in cycles per second or hertz (Hz). Skeletal muscle can become tetanic with frequencies between 15 and 150 Hz, and
although a 20 mA current may not be perceptible at 10 Hz, the same current may cause respiratory paralysis or ventricular fibrillation at lower frequencies.”
Thanks for allowing me the floor for a brief moment Amir, truly. I’m done, back to you.