Brazing Wire to Copper Bar With Induction

Brazing Wire to Copper Bar With Induction Objective: To heat a compacted litz wire bundle for wire stripping then braze the litz wire bundle to a copper block for use in an automotive motor. Material: Compacted litz wire bundle 0.388” (9.85mm) wide, 0.08” (2.03mm) thick copper bar 0.5” (12.7mm) wide, 0.125” (3.17mm) thick and 1.5” (38.1mm) long braze wire & white flux Temperature 1400 ºF (760 ºC) Frequency 300 kHz Equipment • DW-UHF-10 kW induction heating system, equipped with a remote workhead containing two 1.5μF capacitors for a total of 0.75μF • An induction heating coil designed and developed specifically for this application. Process: A three turn helical coil is used for the wire stripping process.The litz wire bundle is placed in the coil for 3 seconds to strip the lacquer 0.75” (19mm) from the end of the bundle. The wire bundle is then scraped with a metal brush to remove the burnt lacquer. For the brazing process a two turn channel coil is used. The litz wire and copper assembly are placed in the coil and the braze wire is fed by hand. The braze is completed in 45-60 seconds. Results/Benefits Induction heating provides: • Consistent, repeatable results • Faster process time, increased production • Even distribution of heating