Abstract: A shielding gas (SG) flow controller for an arc welder includes SG input/output with a controllable valve therebetween, and having a control input, and a controller having a first input receiving a welding signal representing arc current and a gas flow setting controller generating a flow setting output based on the welding signal, representing a desired SG flow. Input and output pressure sensors provide SG input and out pressure to second and third controller inputs, respectively. A flow setting output modifier modifies the flow setting output of the gas flow setting controller based on the SG input/output pressure, the welding signal, and a characteristic of the controllable valve into a control signal input to the control input of the controllable gas valve to maintain a substantially constant SG flow corresponding to the flow setting output substantially independent of actual SG input/output pressures.

Abstract: A shielding gas (SG) flow controller for an arc welder includes SG input/output with a controllable valve therebetween, and having a control input, and a controller having a first input receiving a welding signal representing arc current and a gas flow setting controller generating a flow setting output based on the welding signal, representing a desired SG flow. Input and output pressure sensors provide SG input and out pressure to second and third controller inputs, respectively. A flow setting output modifier modifies the flow setting output of the gas flow setting controller based on the SG input/output pressure, the welding signal, and a characteristic of the controllable valve into a control signal input to the control input of the controllable gas valve to maintain a substantially constant SG flow corresponding to the flow setting output substantially independent of actual SG input/output pressures.