"Andrew R Mitz" wrote in message
...
Twice:
1) Working on a portable battery-operated 120vac source. (My own design).
Got each hand on the 120vac while
wearing the device. Could not breath; could not yell for help. Saved
myself by intentionally falling onto
the battery pack and luckly broke the pack apart.

2) Working on the HV of a 1KW transmitter. Power was off, but caught the
4KV from the filter capacitors.
Threw me across the room. Guess my heart was healthy enough to recover a
normal beat.

AC is more dangerous for two reasons. It causes muscle to contract and
not release, so you cannot let go,
and at 50 or 60Hz it is likely to fibrilate the heart. A single jolt of
DC, if it does not damage too much
tissue, will tend to leave the heart in a (properly) synchronized state so
it can resume a normal beat.

Twisting the thread a little:

I worked with an engineer who was very proud of his floating high-voltage AC
plasma display sustainer drive circuit. Since it was floating, you could
touch any part and not get a shock (or upset the display, either). He
showed my by touching the cases of a few of the power transistors in turn.
Then he jerked his hand back and let out a yell.

Instant second-degree-burn blister.