EP 0213689 A3 19880921 - PLASMA TORCH SHUTDOWN CIRCUIT
Title (en)
PLASMA TORCH SHUTDOWN CIRCUIT
Publication
Application
Priority
US 77260685 A 19850904
Abstract (en)
[origin: EP0213689A2] A plasma torch (11) is supplied with its d.c. operating voltage by a drooping transformer (33) and a rectifier (31), for striking an arc between an electrode (19) and a workpiece (13). If the arc strikes between the electrode and the torch casing (17), the operating voltage drops. A control circuit (51) senses when the operating voltage is below a threshold value and turns off the power supply by opening a solenoid switch (39, 41, 43). This action is briefly disabled each time the power supply is turned on to allow the operating voltage to build up to its normal level, above the threshold.
IPC 1-7
IPC 8 full level
B23K 10/00 (2006.01); H05H 1/36 (2006.01)
CPC (source: EP)
H05H 1/36 (2013.01)
Citation (search report)
- [X] FR 2151219 A5 19730413 - SHAPIRO ILYA, et al
- [X] PATENT ABSTRACTS OF JAPAN, vol. 8, no. 90 (M-292)[1527], 25th April 1984; & JP-A-59 007 480 (MATSUSHITA DENKI SANGYO K.K.) 14-01-1984
Designated contracting state (EPC)
DE FR GB IT
DOCDB simple family (publication)
EP 0213689 A2 19870311; EP 0213689 A3 19880921; JP S62267080 A 19871119
DOCDB simple family (application)
EP 86303754 A 19860516; JP 11043386 A 19860514