General Description of the Modulated Arc Lamp
The SAI™ Modulated Arc Lamp has been developed as part of a system for both visualization and measurement of complex airflows with small, neutrally-buoyant soap bubbles. In particular, it provides an intense, collimated light beam of uniform intensity which can be modulated over a wide range of frequencies. This allows the velocities of the bubbles to be measured from speeds as low as 2 fps to speeds as high as 150 fps. For different flow situations, the beam can be readily modified to optimize the lighting. The complete light system consists of an Cermax Arc Lamp & holder, Optical Shroud with two adjustable apertures and a power supply.
The PS300-13 Switcher Power Supply
The Model PS300-13 Laboratory Power Supply is the latest design by Perkin Elmer Optoelectronics. It is a user programmable lamp power source. There are three membrane switches on the front panel labeled “MENU”, “A” and “B”. These switches permit selection of four operating modes: Continu-ous Current Supply Mode, Variable Time Mode, Internal Modulation Mode and External Modulation Mode. The four modes and their functions are monitored from the front panel by means of a LCD Display. The LCD Display is 4 Lines x 20 Characters wide with blue background and white text. This Display is very convenient to work with, not only for the status and data it provides but also the directions for operation. Output current to the lamp is sent through two single pole shrouded sockets on the front panel and power to the fan and lamp interlock via a 4 way Mo-lex panel mount plug. A 2-way Molex panel mount plug connector also monitors voltage input to the remote igniter located below the lamp holder itself. In addition, the front panel has a 9 pin D-subminiature connector via RS232. This 9 way “D” also has 2 isolated low power outputs, 5V and 12V for customer use. To the left of the connector are two 2mm sockets for ex-ternal lamp modulation input via a square-wave signal input.
Supply Input Power
The PerkinElmer Model PS300-13 Laboratory Power Supply is designed to work directly on either 115 Vac or 230 Vac, 50/60 Hz, input power. Actually, the input voltage can range anywhere from 100 Vac to 240 Vac and the in-put frequency can range anywhere from 47 Hz to 63 Hz. No rewiring or var-iable autotransformer is required to adjust to these variations. This is a dis-tinct advantage of the PS300-13.
The SAI™ OS 300-3 Optical Shroud is designed expressly for use with the PE300 Watt Cermax Lamp manufactured by PerkinElmer Optoelectronics. This unique unit is a xenon-filled, short-arc lamp containing an integral re-flector. The Cermax Lamp is housed in the PerkinElmer HX2 Frame and powered by the PerkinElmer PS300-13 Laboratory Power Supply. The Optical Shroud, itself, contains three basic elements: (i) A condensing lens, (ii) a special aperture cradle and (iii) a projection lens assembly. The condensing lens serves to redistribute the light emitted by the illuminator more uniformly and the special apertures, to change the cross-section shape and size of the beam. The third element, the projection lens assembly, fo-cuses an image of the aperture at the desired distance from the system. A handle on the aperture extends outside the Optical Shroud for insertion, re-moval and adjustment. The Lamp Holder is mounted inside a rectangular Light Shield to eliminate any stray light coming from the Holder. A handle is provided on top of the Light Shield to carry and reposition the Optical Shroud. Also, the bottom base has bumper feet for general support on any flat surface and two threaded mounting holes to affix the light to a tripod or surface plate.