SYNTHESIS

If it were a piece of graphite, which would occur would be a perfect short (and dangerous). Graphite is a poor conductor of electricity, so prevents the short circuit. In return, a large current passes, but ending in "focus" on the tip. The piece of graphite is a constant circular section, but on the tip of our welder, section (or area) of contact is so small that the entire current through there ends up raising the temperature much.

Graphite also has high resistance to "be burned" so our soldering tip does not deteriorate.


This has been a "teaching", but let himself to physics. Explanation well We already know from other physics experiments we publish, the Joule describes the electrical power will be dissipated when driving resistance determined by it current. We also know that the piece of graphite behaves like a resistor. The formula of the Joule effect is: