Abstract: A drive circuit is provided for a target switching element and opens/closes a current path by controlling an absolute value of a potential difference between one end of the current path and an opening/closing control terminal. The drive circuit includes an integrated circuit connected to the control terminal. The integrated circuit includes an absolute value control circuit controlling the absolute value of the potential difference when the switching element is in an off-state, a stabilization circuit stabilizing the potential difference at a value for maintaining the switching element in an off-state when the switching element is in an off-state, a selection circuit selecting one of control of the absolute value of the potential difference by the control circuit and stabilization of the potential difference by the stabilization circuit, and an on-state terminal connected to the control circuit and the control terminal. The on-state terminal is connected to the stabilization circuit.

Abstract: A drive circuit is provided for a target switching element and opens/closes a current path by controlling an absolute value of a potential difference between one end of the current path and an opening/closing control terminal. The drive circuit includes an integrated circuit connected to the control terminal. The integrated circuit includes an absolute value control circuit controlling the absolute value of the potential difference when the switching element is in an off-state, a stabilization circuit stabilizing the potential difference at a value for maintaining the switching element in an off-state when the switching element is in an off-state, a selection circuit selecting one of control of the absolute value of the potential difference by the control circuit and stabilization of the potential difference by the stabilization circuit, and an on-state terminal connected to the control circuit and the control terminal. The on-state terminal is connected to the stabilization circuit.

Abstract: An excellent welding tip in the feed stability of a wire, in the release capacity of foreign matter, and in the stability of current control, and a process for manufacturing such a tip economically, is achieved in accordance with a sectional shape of a guide hole opened and provided to a welding tip. The sectional shape is derived by forming a wire in a passable non-circular shape. The sectional shape of the guide hole may be a polygonal or elliptic shape, or approximately so. In the case of making the sectional shape of the guide hole polygonal, it is more preferable to make it a polygon circumscribing on a circle, for example, such a polygon circumscribing on a larger circle than the outer diameter of the wire to be inserted into the guide hole by 0.02-0.20 mm in diameter. Specifically, it is preferable to arrange the sectional shape as a triangle.