TM-021 PN 35933
Rev 05/06/97
6
GENERAL
DESCRIPTION
The Light-Welder
®
PC-3 is a special purpose UV curing lamp used for pinpoint curing of UV
adhesives, coatings, and potting materials. It emits a 5 mm diameter spot of UV light from a
liquid light guide. This guide can be hand-held for complete mobility or clamped into position on
assembly equipment or work stations for repetitive operations.
The unit consists of a housing containing a 50 watt power supply, circuit protection,
lamp/reflector assembly, cooling fan, light guide mount, non resetable hour-meter, and shutter
system. Electric shutters are supplied with timed and manual shutter operating modes. The
light guide is separate and plugs into the mount. Light is not emitted from the unit when the light
guide is removed. A separate filter mounts on the output end of the light guide to reduce visible
light output where desired. Lamps are rated at 500 hours of life, however, a useful life of 1000
hours can be expected for most applications.
The power supply operates on line voltages of either 100, 120, or 220 Vac, and 50 or 60 Hz
(factory set). AC voltage is stepped down and rectified to DC through a transformer and
fullwave bridge rectifier. A separate high voltage winding on the transformer provides ignition
voltage for the lamps. A blocking diode is located between the power regulator and the high
voltage winding to prevent damage to the regulator circuit. When the lamp ignites, the high
voltage is dissipated across the lamp, although the high voltage winding is always energized. If
the lamp extinguishes due to a momentary power failure, it will reignite after it cools down if the
power switch is left on.
A cooling fan is provided to keep the lamp housing and internal components of the power supply
at the optimum operating temperature. The UV source is a 50 Watt short arc mercury vapor
lamp mounted in a reflector and pre-focused to provide optimum light output. The unit is rated
for continuous operation.
