Soldering temperature torch or a furnace to melt the filler metal. Different equipment is usually required since a soldering iron cannot achieve high enough temperatures for hard soldering or brazing. Brazing filler metal is stronger than silver solder, which is stronger than lead-based soft solder. Brazing solders are formulated primarily for strength, silver solder is used by jewelers to protect the precious metal and by machinists and refrigeration technicians for its tensile strength but lower melting temperature than brazing, and the primary benefit of soft solder is the low temperature used (to prevent heat damage to electronic components and insulation). Since
Alkali-metal thermal to electric converter Alkali-metal thermal to electric converter The alkali-metal thermal-to-electric converter (AMTEC), originally called the sodium heat engine (SHE) was invented by Joseph T. Kummer and Neill Weber at Ford in 1966, and is described in US Patents , , and . It is a thermally regenerative electrochemical device for the direct conversion of heat to electrical energy. It is characterized by high potential efficiencies and no moving parts except the working fluid, which make it a candidate for space power applications. This device accepts a heat input in a range 900–1300 K and produces direct current with predicted device efficiencies of