✔ 最佳答案
You indicate that the rating of the two devices have the same current output. I will assume for the discussion that the 6 ma output is the limit of each device.
Placing the 70 volt pads on the human body you have three conditions to consider. Dry skin has a resistance value of about 100,000 ohms, wet 1000 ohms and if you break the skin 500 ohms.
Applying ohms law then we solve for the possible currents:
I = 70/100000 = 0.0007 amps or 0.7 ma
I= 70/1000 = 0.07 amps = 70 milliamps but your device is limited to 6 ma, thus either a fuse opens or some other OCPD limits the current.
I = 70/500 = 140 ma and again your device is limited to 6 ma, thus either a fuse opens or some other OCPD limits the current.
Now do the same calculations for the 5000 volt device and you will find that you will reach the maximum output of your device in all three cases.
So what does this mean? Likely the 70 volt device applied to dry skin "MAY" not harm you. In all other applications of the 70 or 5kV devices, you will be able to send 6 ma of current through the body. In one case you develop a power of =70*.006 = 0.42 watts, in the other case you develop a power of = 5000*.006 = 30 watts.
At 6 ma, it is not likely that you will cause heart fibrillation so you might live through the experience, however, at 5kV and 6 ma, the 30 watts application of power will burn your skin tissue and or muscle tissue, etc. over the time you apply it.
Hope this helps,
Newton1Law