Most old
timers put one
hand in their pocket so that there is no path. You will still get an
alarming little shock but it won't be lethal.
Oh dear - maybe I now class as an old timer ;-)
I learnt respect for hight voltage in the 1970's when I built an
experimental pulsed carbon dioxide laser. This thing had an array of high
voltage ceramics totalling 20nF charged up to 20kV (4 Joules). In the dark
you could see any sharp corner glowing blue with corona discharge. Boxed
the thing up in a copper foil lined perspex box with a hefty strap to ground
to make sure that any unpleasant event went somewhere safe.
And yes - while measuring anything on this lethal beast (using a P6015) one
hand was very firmly in the pocket. I nearly gave a colleague a heart
attack with one episode - I managed to get the probe tip half way between
the top and bottom plate that sandwiched the capacitors - and it arced
across top plate-probe-bottom plate with a huge BANG. Gave me such a fright
that I yelped, and my colleague ran in with a white face expecting to find
me on the floor. It really stuffed the screw-on tip of the probe too....
Although that was bad enough, this thing spat 0.5 Joule pulses of light out
(in the infrared) with a pulse length of about 100ns - a peak power of 5MW.
Of course over the years I have had the odd lapse of concentration - like
the belt from the 7704A HT supply - but fortunately I've got away with it so
far. Might have to revisit the care I take now the years are passing.
Craig
