Electric heating – Metal heating – By arc
Patent
1997-07-28
1998-12-01
Paschall, Mark H.
Electric heating
Metal heating
By arc
21912154, 21912159, 21913032, B23K 1000
Patent
active
058441972
ABSTRACT:
An arc retract circuit for use in a plasma arc system with a torch having an electrode and a nozzle, a power supply for providing a D.C. current, a power circuit for connecting the power supply across said electrode and a workpiece to be cut, a power switch for connecting the nozzle to the power supply when in a closed condition defining a pilot arc mode of operation and for disconnecting the nozzle from the workpiece when in an open condition defining a cut mode of operation, an amplifier for regulating said power supply to a first set current when in the pilot arc mode and a second set current when in the cut mode, and an arc retract circuit for shifting the power switch from the open condition to the closed condition, which arc retract circuit includes a current sensing circuit for creating a first signal representing the actual current applied by the power supply to the power circuit, structure for creating a second signal representative of a current level below the second set current, and switch operations structure for closing the power switch when the first signal is substantially equal to the second signal.
REFERENCES:
patent: 4017707 (1977-04-01), Brown et al.
patent: 4156125 (1979-05-01), Brown et al.
patent: 4300036 (1981-11-01), Johansson
patent: 4410788 (1983-10-01), Summers et al.
patent: 4766286 (1988-08-01), Iceland
patent: 4901720 (1990-02-01), Bertrand
patent: 4906811 (1990-03-01), Buil
patent: 4943699 (1990-07-01), Thommes
patent: 4983807 (1991-01-01), Yamada et al.
patent: 4987285 (1991-01-01), Dallavalle et al.
patent: 4996407 (1991-02-01), Traxler
patent: 5036176 (1991-07-01), Yamaguchi et al.
patent: 5235162 (1993-08-01), Nourbakhsh
patent: 5290995 (1994-03-01), Higgins et al.
patent: 5528010 (1996-06-01), Herwig et al.
patent: 5530220 (1996-06-01), Tatham
patent: 5620617 (1997-04-01), Borowy et al.
patent: 5630952 (1997-05-01), Karino et al.
patent: 5660745 (1997-08-01), Naor
Paschall Mark H.
The Lincoln Electric Company
LandOfFree
Arc retract circuit and method does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Arc retract circuit and method, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Arc retract circuit and method will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2397306