BINAY LED Matrix Annunciator Windows
utilise solid-state LEDs and offer the following advantages over
filament bulbs:
- A long life of 100,000 hours (nearly 11 years on a con-tinuous
burning basis - as such, the question of re-placement does not
arise)
- · Extremely low current consumption (20mA - 40mA) - this may
reduce complexity in solid-state logic cir-cuits, since driver
transistors and thyristors can be avoided. Furthermore, when using
filament bulbs, the high ratio of cold/hot resistance requires the
use of highly over-rated electronic components, which can
withstand high current surge at switch-on. With the use of LEDs,
this problem is eliminated.
- Totally shock-proof and vibration-resistant (as LEDs are
solid-state devices)
- Ability to withstand a wide range (+/-25%) of voltage
variation without any appreciable change in life or light
output.
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However, the greatest advantage that
the LED An-nunciator Window offers over the filament bulb type is the
reliability of indication. The failure of the fila-ment bulb at a critical
juncture due to its limited life or as a result of vibration can cause an
expensive mishap, and it is for this reason that many design-ers emission
of the LEDs used, etc. Furthermore, the material with which the legend
plate is made has to be highly translucent.
BINAY LED Matrix
Annunciator Windows use multi-ple high-intensity LEDs to achieve a
satisfactory and uniform light output. These LEDs are positioned on a
replaceable printed circuit board in a matrix form, and as a result, the
legend plate is illuminated in an extremely uniform manner. This plate
itself has just the right amount of transmission so as to optimise the
compromise between uniform diffusion over its outer surface and too much
absorption of light.
For better legibility in high ambient light
conditions, high contrast is required between the light trans-mitted
through the window and the light incident on its surface. As such, a dark
background for the legend plate (which reflects a minimal amount of
in-cident light) gives highly improved visibility.
For such conditions (where the ambient light is high), we can also provide
'Negative' legend plates. These have a dark background with transparent
letters (as opposed to a white background with the legend inscribed in
dark letters). This gives a supe-rior effect, as a result of the high
contrast obtained by the transparent legend being back-lit on a dark
background.
Legend engraving can be furnished either on a clear
plate or a black background. On request, legends on photo-film
transparencies can also be supplied.
designers and users prefer to install these LED windows even though the
cost is higher.
LEDs, however, suffer from some limitations, which
require suitable modifications to be made in the de-sign of the end
product. Filament bulbs radiate light in all directions, and one light
source is usually ade-quate; however, when using LEDs (which have
di-rectional light emission) a multiple-LED source is required, arranged
so as to give wide dispersal of the emitted light over the entire
annunciator legend plate. To enable this result, various factors have to
be considered in the design of the window - its depth, the positioning of
the LEDs, angle of light.
BINAY LED Matrix Annunciator Windows are avail-able in any voltage rating
from 5V to 220V. Legend colours can be red, green or yellow-white, with
the possibility of different partitions in different colours.
A
flashing arrangement can also be provided. All types in high voltage
ratings (110V/220V) can be supplied with internal circuitry for fast
flashing (120 flashes per minute), slow flashing (60 per minute) and
steady conditions. Various terminations such as solderable lugs, screw
terminals, clip-on ('El-mech' type) conductor terminals, or multi-pin
con-nectors can be provided.
Annunciation Arrays:
Annunciator windows can be supplied in arrays on special order. The
num-bers of rows and column should be intimated. An external bezel fixes
the array on the main panel.
BINAY LED Annunciator Windows come
with a free-replacement guarantee against manufacturing defects and
operational failure for a period of one year from the date of purchase.
The normal life of an LED, however, is 100,000 hours (11 years)
cal-culated on a continuous burning basis, as com-pared to 1,000 hours for
a properly manufactured filament lamp (a ratio of 100:1). As such, the
ques-tion of replacement of an LED indicator does not normally
arise.
BINAY LED Matrix Annunciator Windows are available
in the following standard types:
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