Mercury Arc Power Supplies for Lamps

by John Smith Writer

In both outdoor and indoor luminaries, the light-emitting diodes are rapidly replacing fluorescent and incandescent technologies. Thanks to the durability, design flexibility, and long life service these offers. Whether you are building new fixtures, fixing the already established retro fitting lamps, or purchasing new fixtures for your LED lights, it goes without saying you will need to find the correct power supplies for them to function properly.

Note that this is not only dependent on the design equation, but in order for the lighting to be realized on its full efficiency, durability, and longevity, you will need a constant current and a power supply that match up to your needs and requirements for your application and the power factor required for your LED.

Starting with the Basics: What are Mercury Arc Lamp Power Supplies?

LEDs are non-linear devices, unlike incandescent bulbs. That means these would require current limiting devices in order to prevent the lights from being overdriven. Another thing to note is that LEDs only begin to produce light once their supply voltage is equal to greater than the diodes forward voltage drop. To prevent this kind of inconvenient behavior, the power source, for instance a mercury arc lamp, must provide a suitable voltage at the appropriate current level. To limit the current to the maximum specified by the LED manufacturer is to select a power supply with an output voltage above the forward voltage.

This allows for the current to be set at the maximum to provide the users with the greatest efficiency and reliability and to achieve the exact brightness required and also remove the effects of junction temperature as the temperature fluctuates.

So when the varying current and amount of light emitted varies, a better way to tackle this is with the help of a mercury arc lamp. To meet the ignition and the operational requirements of varying designs, temperatures, and light emissions, these require direct current to the power supply which is specifically designed. A typical power supply, offered by the major manufacturers worldwide, provides from 150W over to 7kW in order to heat the cathode to thermionic emission temperatures. Additional requirements depend on your use and the overall ripple size, a maximum level of inrush current excessive thermal shock during ignition. And most importantly, the power supply must be able to ensure long lamp life and light stability. Finally, as the voltage significantly increases and decreases initially during the light warm-up period, in cases like these the power supply must be able to adjust the applied current over the different ranges.

Mercury arc lamps are commonly used in:

Outdoor lighting
Flashlights
Blueprinting
Endoscopy

Selecting the Right Power Supply

The ultimate decision depends on the type of power supply selected for a lighting application. So first things first, you need to consider the operating environment. That is the application for indoor or outdoor use. For instance, the Xenon short-arc mercury power supply is a specialized type that produces light by passing electricity through ionized gas at high pressure. These power supplies are usually used in movie theaters and searchlights as well as industry and research to simulate sunlight. Moreover, xenon short arc power supplies comes in two distinct varieties, one which contains only xenon gas and the other xenon-mercury with a small amount of mercury metal.

Apart from this, it is also important to define the overall power requirements. For instance, if you are running on a single luminary, you may only require a small power source but if you are having a complex system to work with you may need hundreds of watts of constant current supply. You need to consider if the power supply will be required to work in simple constant voltage mode or constant current mode.

When it comes to size, you can talk to your manufacturers and explain to them where the power supplies need to be installed. And be rest assured they will equip you with a variety of power supplies in different sizes to fit your needs.