| 摘要 |
<p>The system can be used with all types of protective helments or hand-held screens employed to protect human eyes and faces from arc radiation and weld spray. The system pref includes a transformer providing a very low voltage, e.g. 12-24 volts, to a halogen projector lamp of 25-30 watts, via a single- or double- pole switch. The projector lamp illuminates the welding zone so it can be seen by a worker through a safety glass screen. When the arc has been struck, the lamp is switched off. The lamp can also be used to illuminate the welding zone without placing a safety screen between the zone and the worker. It is very difficult or impossible to see the welding zone through a dark glass safety screen before the arc is struck; it is therefore difficult to adjust the electrodes. The invention uses a strong projector lamp so the welding zone is visible through the screen before striking the arc.</p> |
