An apparatus for bonding a conductive lead to a conductive terminal of a device by the use of a conductive metal ball is disclosed and claimed. A ball-forming wire comprises a first conductive metal having a first melting temperature. A clamping surface has a closed position in contact with the ball-forming wire. A wire-clamping actuator is coupled to the clamping surface and is electrically connected to a clamping signal source. A sparking pin comprises a second conductive metal having a second melting temperature higher than the first melting temperature. The sparking pin is electrically connected to a power source. A current detection transformer includes a magnetic core at least partially encircling the ball-forming wire. An analyzing circuit is electrically connected to the current detection transformer.