Branson Ultrasonic Welding Machine Model -186P plastic welding power supply with Branson 801 actuator and plastic welder model 8600 Branson Ultrasonic 802 Converter/Transducer Part No-101-135-034 The CONVERTER is the motor of the ultrasonic welding system. This component produces a motion via a piezoelectric effect, which is to say that the converter expands and contracts when electrically excited by the power supply. At 20 kHz, this expansion and contraction is approximately .0008 of an inch or 20 microns at the face of the converter and the movement is in an axial motion. The converter is matched to the output frequency of the power supply. There are different converters for 15, 20, 30 & 40 kHz ultrasonic welders. See less