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Main Product: Lamp Ballasts

Light Control Considerations:



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Tungsten


Advantages:
In some Machine Vision applications, Tungsten lamps are ideal because of their:

• Simplicity    • Size    • Continuous spectral output

Hence, they are perfect for small target applications and fiber-optic bundles.


Shortcomings:


• Tungsten light sources generate high levels of infra-red light - that effectively "snow-blinds" CCD cameras, therefore, require IR filtering.
• They generally do not have much blue output.
• They have a short lamp life.
• They also have typically erratic light output in Machine Vision applications.


MERCRON's Solution:

MERCRON's Tungsten Light Controllers regulate the tungsten light-source with a high-frequency, sinusoidal waveform. This type of current reduces both start-up shock and long term filament erosion resulting in a 50%-to-100% increase in usable lamp life.

Tungsten lamps can't be trusted to maintain constant light output because heated sockets and loose connections are all too common, even in well-designed vision systems. Tungsten / Halogen lamps become so hot that even the "best" sockets will corrode and expand with heat.

Vibrations of the lamp in its socket will periodically scrub away the corrosion, causing small changes in socket resistance. These seemingly minute changes produce intermittent light-output that is visible to the Vision system.

Current-controlled DC power supplies can "compensate", but are slow to respond to circuit variations.


The MERCRON Advantage


MERCRON's Tungsten Light Controllers use light-feedback and high frequency drive to instantly correct any deviation so that the light remains perfect.


No Small Achievement

When MERCRON's own temperature-compensated photodiode is used with a Tungsten Light Controller, the light can be held to within a few degrees-Kelvin. Discriminating scientists and engineers have responded with enthusiasm when they have experienced the performance of these light controllers.

MERCRON's Tungsten Light Controller models are encoded to indicate just how many lamps can be regulated - as long as the lamps are connected in series; e.g., model TX300-72 can regulate:

  • One 300-watt / 72-volt light-source;
  • Or three 100 W / 24V lamp;
  • Or four 75 W / 18V lamps;
  • Or six 50 W / 12V lamps;
  • Or twelve 24 W / 6V lamps; ...etc;

Another MERCRON Advantage...

Moreover, MERCRON Light Controllers are voltage tolerant. A 300-watt load, for example, could operate over a range of 60-to-84 volts. That is, six 50W / 10V lamps could be used instead of six 50W /12V lamps. This offers the user both versatility and latitude.


MERCRON's Tungsten Light Controllers:

•    Can regulate various number-of-lamp combinations as long as lamps are connected in series, and dependent upon the model's voltage tolerance (See above); e.g., from one 500-watt lamp up to twenty 25-watt lamps - with other combinations in-between
•    Have both Optical & Power Adjustment ratios of 100:1.


Special Consideration: Correlation of Color Temperature & Power
In MERCRON's Tungsten series spec, Optical Ratio is listed as 100:1 and the Power Adjustment Ratio is also listed as (approximately) 100:1. Although, the light output can actually be adjusted to be greater than 100:1, the user should be aware that the lamp's color temperature will change considerably; i.e., a lamp at 50% power will have a color temperature significantly different than a lamp @ 100%.


Correlation of color temperature and power - at different levels - is non-linear and will vary from lamp to lamp as well. The designer should keep these characteristics in mind when developing an Illumination System for a color application.