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Unread 30-12-2006, 14:04
Unsung FIRST Hero
Al Skierkiewicz Al Skierkiewicz is offline
Broadcast Eng/Chief Robot Inspector
AKA: Big Al WFFA 2005
FRC #0111 (WildStang)
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Re: What to do with big capacitors?

Quote:
Originally Posted by Salik Syed View Post
Al:
I think it has something to do with the fact that as you increase frequency the current has more and more of a tendency to flow near the edges of the conductor.
Salik,
This is true for current in a conductor and it also occurs with ever increasing voltage. This is why high tension lines are frequently made with a steel core for strength with a suitable high conductance outer shell. However, this effect does not take place inside the human body as current still travels through the path(s) of least resistance. On a wet body that may very well be along the outer surface but... The human body still operates with miniscule currents that control muscle function, nerve transfer and thinking. Large currents interfere and often fatally damage these transducers. In the case of many electrocutions, the heart is merely waiting for the next large pulse to beat. If other damage is minor and external means are used to keep breathing and blood flow moving, the heart can eventually return to operating on the miniature pulses it receives. This is why it so important to learn CPR. Of course, there is no substitute for learning safe operating practice and staying away from situations where harmful conditions can occur.
I have seen tissue damage from both high voltage and from RF voltage. As with lightning, the only thing that is predictable about body contact with these voltages is that they are unpredictable.
I forgot to mention that the caps in the power supply for one of the transmitters I work on are 4 mmf @ 50kV. The power supply is 30-35kV at 2 amps. The caps are about 6 x 24 x 40 inches, oil filled and reside in an explosion proof enclosure.
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Good Luck All. Learn something new, everyday!
Al
WB9UVJ
www.wildstang.org
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Storming the Tower since 1996.