SUNSTONE PicoDC, Руководство пользователя

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Users Guide
Picó
• Weld Comparator
• Full welder parameter cloning
•
Lock-Out Mode
• PLC communication ready
• Software Updates
•
Multiple Languages available
• Alarms and warnings
What is Direct Current Resistance Welding?
The Sunstone Pico welder converts the AC power coming from the wall to DC power and utilizes an internal
control system to regulate and maintain the weld discharge for accurate, repeatable welds. The control system
allows for fine tuning and manipulation of the weld energy to adjust for various welding applications. DC power
can be ideal for very fine wires and thin components that need the precision other welding power supplies do
not provide. The peak current of DC welders is lower than that of CD welders, but more sustainable throughout
the weld process. The sustained peak currents are ideal for using thermocompression electrodes because the
constant current provides a more even heat during the length of the weld.
DC RESISTANCE WELD FORMATION
Resistive spot welding relies on metal resistivity to heat and fuse metal. Current is generated by the DC power
supply and is passed through the workpiece metal. Energy is dissipated in the form of heat due to the metal’s
resistance to the current. This resultant heat melts the weld materials, fusing them together. There are two
phases to the melting process and the welder must overcome both the “Contact Resistance” and the “Bulk
Resistance” of the material.
Contact Resistance
On the micro scale, surfaces of materials are rough and uneven, resembling peaks and valleys, as shown in Fig -
ure 2.1. When two surfaces are pressed together, contact is only made in a limited number of locations (where
the peaks meet the peaks), instead of across the entire surface. These contact points act as resistive bridges
for the current to flow across and create contact resistance. During the first few milliseconds of weld formation
these bridges melt, allowing other bridges to come into contact to continue the melting process.
Figure 2.1. Surface roughness limits surface-to-
surface contact. More contact points result in a
lower contact resistance.