User Interface with Large LCD Display

A power switch and all manually controllable features of the OPS model power supplies are accessible from the front panel. Four horizontal push buttons each activate a horizontal menu that allows for configuring of lamp operation mode, shutter, display mode, and setup with the help of a corresponding vertical menu that is activated as well. These functions are conveniently displayed and easily navigated by the LCD display on the front panel of the power supply

Constant Current, Power, and Intensity Control Modes

The OPS Series power supplies allow the lamp to be operated in power, current, and intensity control modes. There is very little difference in the short term output stability when operating an arc lamp in constant current or constant power mode. However, the differences appear as the lamp ages. Even with a stable power supply, deposits on the inside of the lamp envelope are visible as the lamp electrodes degrade, changing the electrical characteristics of the lamp. The distance between the cathode and anode of the arc lamp increases, raising the lamp’s operating voltage. In Power Mode, the lamp is operated at a constant power setting. As the voltage cannot be changed, the current is raised or lowered to maintain the power at the same level. As the lamp ages, the radiant output decreases. However, the lamp life is prolonged. After ignition the light bulb icon on the OPS Power Supply's LCD screen illuminates, indicating the lamp is on. Real time power supplied to the lamp is also visible to the user during operation. Prior to igniting the lamp, a user can the maximum operating power of the lamp and the operating power he or she would like to operate the lamp at. This prevents accidental damage to the lamp caused by supplying too much power. In Current Mode, the lamp is operated at a constant current setting. As the voltage cannot be changed, the power is raised or lowered to maintain the current at the same level. As the lamp ages, the power is increased. This results in greater optical output which to some extent may help compensate for a darkening lamp envelope. However, the lamp life is reduced due to the increase in power. Intensity Mode requires the use of the LIK-LMP light intensity controller kit (details below), also made by Oriel Instruments. When operating in the lamp in Intensity Mode, the user can adjust the Flux Set parameter until the desired output intensity of the lamp is attained. When the desired Flux Set has been established, the user can adjust the Flux Calibration Factor (Flux Cal) setting to change the displayed Lamp Intensity on the LCD screen. Adjusting the Flux Calibration Factor does not change current/power supplied to the lamp or its output intensity. Only the Lamp Intensity displayed on the LCD screen is changed. A photodetector calibrated to NIST or other widely recognized standard is often used to establish a Flux Set. Then, the LIK-LMP is substituted in place of the calibrated detector, and the Flux Calibration Factor is adjusted for the LIK-LMP to output the response of the calibrated detector during operation of the lamp. This saves the user both the cost and inconvenience of returning a photosensor to a metrology lab for re-calibration, that would otherwise be required had the calibrated sensor been used during lamp operation.

Additional Light Stability with LIK-LMP Light Intensity Controller Kit (sold separately)

Although Oriel's power supplies are highly regulated, there are factors beyond the control of the power supply that may affect light output. Some of these are lamp aging, ambient temperature fluctuations, and electrode erosion. For applications where high stability light output is especially critical, the LIK-LMP Light Intensity Controller Kit is suggested in order to compensate for such factors. It works in conjunction with the OPS Series power supplies to maintain a stable, long term output. The LIK-LMP utilizes a TE cooled silicon detector as its light sensing head. When used with the OPS-A Series Arc Lamp Power Supplies this detector monitors light output from the arc lamp source. Constant feedback of the light output allows the OPS Series Power Supply to determine how much voltage/current should be supplied to the light source in order to keep its output intensity constant as the light source ages. Using the cables supplied with the LIK-LMP for interface with the OPS Series Power Supply, the temperature of the Si detector is monitored and the current supplied to the TE cooler is controlled as well. This stabilizes the temperature of the Si detector, creating consistent detector feedback independent of ambient temperature variations. The OPS-A Series Arc Lamp Power Supplies are capable of controlling the temperature of the Si detector over a range of 0-25 °C

Integrated Shutter Control and Timer Features

The shutter control feature of the OPS model power supply is useable in power, current, and intensity control modes. Any shutter which responds by opening or closing when receiving a TTL signal can be controlled by the OPS Power Supplies. This includes Oriel’s model 71445 low-cost TTL shutter and the shutters designed into the Oriel Solar Simulators. A BNC connector is located on the rear panel of the power supply to output these TTL signals to the electronic shutter. The shutter can be manually opened or closed by pressing the SHUTTER button on the front panel of the power supply. RS-232 or USB control of the shutter is possible as well. Utilizing the OPS Power Supply's shutter control feature enables Timed exposure control mode. The exposure or open time of the shutter and number of repeat cycles is set by the user. Exposure times can be paused and resumed at will or reset to 0 in the middle of an exposure with the easy to use push buttons on the front panel. When Oriel's LIK-LMP Light Intensity Controller Kit is used with the shutter timer feature, the OPS power supply can be programmed to deliver a specified dose of light to a sample. The dose is calculated as the total light flux multiplied by the time the shutter is open. The dose feature is very similar to the internal shutter timer feature but instead of specifying a shutter open time, the user specifies the desired dose. The shutter is left open for however long it takes to reach this dose and then closes. The user may set the close time and number of cycles for the sequence to repeat. Just as with the internal shutter timer feature, the user can pause, continue or abort an exposure whenever necessary.

Configuration Settings

The OPS model power supplies are capable of storing up to four setups. These Setups consist of lamp operation mode with relevant parameter limits (power, current, flux, etc.) and timing preferences for shutter and dosage control. This allows a user to easily recall previous testing parameters to create a repeatable setup. 

Safety Interlock Prevents Accidental Exposure

Newport’s Oriel Power Supplies have a safety interlock feature which must be satisfied before the power supply will power the lamp and which, if broken during operation, will disable the power supply. Overheating of the housing or accidental opening of the door will automatically shut down the power supply.

OPS Power Supply Demonstration Video

Power Supply Replacement Guide

Users seeking to replace their existing Oriel Arc Lamp Power Supply with an OPS-A Power Supply should consult the table below. Unlike the previous generation of Legacy Power Supplies which was limited in compatibility by lamp power rating and lamp type (Xe, Hg, HgXe), the OPS-A Power Supplies are capable of operating all Oriel DC Arc Lamps, and only lamp power needs to be considered.

Operates Lamps with High Light Stability

When selecting components to assemble a complete illumination system, the OPS-A Series Power Supply is a vital component for operating a DC arc lamp with minimum light ripple. The OPS-A150 operates Oriel's DC Arc Lamps with <0.1% rms light ripple. The OPS-A500 and OPS-A1000 models operate Oriel's DC Arc Lamps with <1% rms light ripple. Oriel Instruments offers all the necessary components required to assemble such a high stability DC arc lamp system.