Amada Miyachi Unitek STA-100A, Operation Manual, Page: 16 / 154

CHAPTER 1: DESCRIPTION
STA SERIES AC CONTROLS
1-2 990-351
Standard Features

Operates on 50Hz or 60Hz, self-detecting, no adjustments needed.

Multiple pulse capability.

Controlled current ramps.

300, 600, 1200, 1800, or 2200 amp SCRs with constant current control.

Water-cooling of the 600A and larger SCR assemblies.

Programming features with LCD display.

Programmable for spot, repeat, successive, or chaining modes.

Continuous seam weld and roll spot seam welding capabilities.

Programmable for 64 welding schedules.

Valve drivers for up to four user-programmable valves are included in the basic unit.

Supports air-actuated Retraction Valves.
Optional Features

A circuit breaker that removes power to the Control when the door is opened (STA-200
through STA-800).

A Communications card that allows remote data collection and remote programming of the
Control.

A Cascade Board Option that allows a Control to operate multiple SCRs. Depending upon the
model, up to 8 SCRs can be cascade fired.

A Valve Expansion Option to increase user-programmable valve-driver capability to 12 valves.

A Voltage Monitor Option that allows you to compare results against high and low limits, and
monitor either peak or average voltage. This feature allows you to select when the voltage is
monitored, either during both weld periods (excluding up/downslope) or during the last cycle of
each weld only, which is useful for welding to a specific resistance.

A Force Control (Force Output) Option that can control up to 8 separate (user supplied)
electronic pressure regulators. Force is programmed in pounds using front panel controls. The
Control makes calculations to create accurate air pressure. Calibration is a simple 2-step
procedure using front panel controls.

A Pressure Control Option (Force Input) that uses differential pressure sensors is available for
up to eight channels. You may use this feature in a Force-Firing function (welds only when
correct pressure is reached), or as a pressure monitor to see if air pressure is in the desired
range. Force firing can reduce cycle time by eliminating the need to program squeeze time, and
it assures that every weld is made at the optimum force.
High , low and Firing Force limits are programmed in pounds using front panel controls.
Calibration is a simple 2-step procedure using front panel controls. Calibration correlates the
pounds desired to the equivalent air pressure. This feature will check the air pressure for up to
5 seconds at the start of the squeeze delay period. If the force is within limits, the weld will
continue. Otherwise, the weld will be aborted and an alarm will be triggered. If the pressure
was out of limits at the end of a weld an alarm will be triggered.
NOTE: This feature requires presence of the Force Control (Force Output) board, but does not
require usage of the Force Output feature in order for Force Input to be functional.