Principle Of Operation - Emerson Branson LPX Instruction Manual

2.1

Principle of Operation

The LPX Power Supply converts AC line voltage to 20, 30 or 40 kHz electrical energy. This
high frequency electrical energy is supplied to a converter where it is transformed to
mechanical motion at ultrasonic frequencies. The heart of the converter is a lead zirconate
titanate electrostrictive element which, when subjected to an alternating voltage, expands
and contracts. The converter vibrates in a longitudinal direction and transmits this motion,
either directly or through an amplitude-modifying booster, to the horn. The horn, an
acoustic tool, transfers this vibratory energy directly to the parts being assembled.
Figure 2.1 LPX Power Supply
The LPX Power Supply is a constant amplitude device. As the load or pressure on the horn
face increases, the power supply develops more power to maintain the set amplitude.
When the horn is operated in air, minimum power is required to maintain amplitude.
For any given application, more power results when a horn of higher gain or larger
radiating surface (mass) is used, or when any horn is driven at higher amplitude levels.
The LPX Power Supply offers 3 operating modes to control how ultrasonic energy is
applied: Continuous, Time, and Energy. Ground Detect is an optional control feature that
can be ordered and factory installed for the LPX Power Supply.
By setting various operation parameters, you can precisely control the way in which
ultrasonics are applied. You can:
• Specify the time duration of the weld cycle
• Adjust the amplitude setting between 10% and 100% of maximum amplitude
• Set the maximum allowable energy for the weld cycle, so that ultrasonics will stop automatically
when the specified energy is reached
• Stop ultrasonics when the horn contacts metal (Ground Detect option)
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