Controls & Transformers
Questions and Answers
Weld controls can be incorporated into automated weld cells and take their initiation signals from the numerical control center of the cell. The weld control will control the actual weld functions being performed within the time allotted by the NC center. Weld controls are capable of sending whatever data is needed back to the NC center to record that the functions are complete or data generated during the operation.
Reference: RWMA - Resistance Welding Manual 4th Edition
Weld controls have the capability to handle a modest number of machine control functions. They are capable of functioning as the weld control and machine control for small cells with a modest number of non-weld functions.
Reference: RWMA - Resistance Welding Manual 4th Edition
A valve transformer or valve power supply provides the low voltage power to activate the valve which controls the air to the pneumatic welding cylinder. This pneumatic cylinder is the source of force in the welding operation. This same transformer/power supply could send a signal to a servo to initiate its operation.
The weld control logic monitors all input information and stores all programs and initiates all necessary commands to complete the required functions. In simple terms when the input signal for a weld is received from the foot switch or other input source the control logic starts the squeeze/weld/hold/off sequence as programmed.
AC controls all have microprocessors that activate contactors to control the time and amount of power that is delivered to the part to be welded. These contactors could be considered electronic switches. They are made up of two SCR’s. There is one SCR for the positive and a second for the negative half of the AC sine wave.
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