There is a misconception about the dangers of current and voltage.
Originally Posted by andsetinn
To correct some info here. High Voltage is not dangerous unless it's accompanied by high Amperage. It also works the other way around to high Amperage is not dangerous unless it's accompanied by high Voltage. This was repeatedly proved by Nicolai Tesla. For electricity to be dangerous it has to have both high Voltage and Amperage.
As engineers we are always concerned with the safety of the user and consumer. I make this correction to your statement that it takes a HIGH VOLTAGE AND CURRENT to be dangerous. This is INCORRECT, and I only say this to avoid an accident.
Please understand that it is not the high voltage or the current that makes this lethal, it is the combination and discharge time.
It is not the voltage or the current alone that we look at. The danger is the amount of JOULES
(ENERGY) that get transferred. A JOULE is a WATT-SECOND. You can produce as many JOULES as you want at any desired voltage.
We are talking about capacitive discharges here, so here is some advice:
To measure the JOULES that capacitor bank puts out you use the following formula:
Where C is in FARADS.
So for example if you have a circuit that has an 800,000 uf capacitor charged at 18 volts you will generate 130 Joules. This WILL HURT YOU!!! ...and put a hell of a BURN on your body. Also, the current transferred by this can be in excess of 500amps in less than a few milliseconds. If this energy was to go through your body, you would get a hell of a jolt and most probably your heart could stop.
As I said earlier, it only takes less than 25 Joules to punch a hole and generate lots of sparks through aluminum foil and you can weld a small wire with 40 Joules.
***Lets assume that an r/c magnet zappers works at around 120 volts, and it is using a 10 Farad capacitor bank, then the energy being transferred by the discharged capacitor will be 72,000 Joules. This will generate in excess of 5,000 AMPS and it will be transferred in less than 700 milliseconds
That is a TON of ENERGY.
The Joules generated by the capacitive discharge zappers can be in the thousands…and the current could be in excess of 20,000 amps. With a transfer time of milliseconds.
***This is only an example
Do you know how many Joules it takes to restart a heart? Pay attention next time you watch ER when they say, "CHARGE TO XXX JOULES” You will be surprised at the charge. It is minimal compared to this.
Please be careful when working with capacitors and coils if you do not know what you are doing. It is best you ask for advice from those who work with this on a regular basis.