Originally Posted by
JohnDThompson
Trek developed an induction heating system for brazing frames in the mid-80s. It required specially shaped copper blocks to fit around the joints; each joint and frame size needed its own set of blocks to ensure even heating. Automated wire-feed machines fed a pre-determined length of brass wire into the joint after it was heated for a pre-determined time. Shorelines were touched up by hand while the joint was still hot. The system was only used for a couple/few years, as it was developed just as non-steel frames started to become fashionable, and was scrapped when the market became almost exclusively aluminum and carbon fiber.
What you are describing sounds more like resistance soldering/brazing, where electrical contact by a tweezer, clamp or block type of electrode arrangement causes electric current to flow through the workpiece, directly heating it. I have used the process in electronic soldering, where copper or graphite electrodes are used.
Inductive heating uses coils to "induce" currents in the workpiece without contacting it directly.
Both are quite efficient because they directly heat the work, rather than conducting heat into the work by flame or contact e.g. soldering iron/gun; virtually all of the heat produced is in the workpiece.