Equipment for spot welding may be configured as a standard welder with spot welding tips on the horn or fixture, or as an ultrasonic power supply and a hand-held welding tool. The hand-held tool is compact and lightweight, and may be designed with a pistol grip or a spring-loaded sleeve. Ultrasonic spot welder is available in either 28 or 40 KHz. With hand-held units, the ultrasonic welding cycle is initiated either by applying pressure against the parts being welded (using the spring-loaded unit) or by activating a trigger switch on the pistol-grip units. Welding duration is controlled by the operator or the power supply, depending on the equipment used.
In addition, the units may be used with a microprocessor-controlled power supply to enable welding in energy as well as time modes. Welding in energy would compensate for variations in pressure applied by the operator by adjusting the weld time. Using these power supplies also allows setting audible alarms for added control. The horns used in ultrasonic spot welding are tapped to receive standard replaceable, threaded tips whose configurations and sizes are determined by the thickness of the material being assembled. Tips are not limited to standard shapes; special configurations are available or may be made to order.
