| 摘要 |
PURPOSE:To make a circuit of a welding controller provided with an electric shock preventing device and a remote control simple by controlling an electrostatic induction type transistor of (n) channel with a variable voltage source for gate. CONSTITUTION:The circuit is constituted of an AC power source 1, an ordinary transformer 2, a semiconductor diode 3 for half wave rectifying, an electrostatic induction type transistor 4 of (n) channel, a gate variable voltage source 5 of (n) channel, an adjusting knob 6 of the voltage source 5, a welding rod connecting terminal 7, an arc side terminal 8, an electric power source 9 generating the gate voltage which cuts off the TR4 of (n) channel, and a selection switch 10. The transformer 2 and the circuit enclosed by a dotted line are separated by two electric wires and the power source 6 is beforehand controlled to the current and voltage characteristics necessary for welding. Hence, if welding is executed by flickering the switch 10 and the switch 10 is connected to the power source 9 side, the TR4 is cut off and no current flows despite contacting of the terminals 7, 8. It is equally well to use a thyristor of electrostatic induction type of (n) channel. |
