Visual Instrumentation Ltd.

High-intensity LED arrays are an ideal light source for many high-speed digital video and related imaging tasks.  Typical LED luminous efficiency is near 90% compared to 20% or less with typical tungsten-halogen lights, resulting in high output intensity with virtually no heat in the light beam.  In addition to producing 6000°K white light, LEDs are also available with: Red, amber, cyan, green and blue LED's for scientific applications using monochrome cameras. 

Current generation LEDs have a typical luminous output of 85 to 180 lumens, depending on the frequency response and color temperature of specific LED's.   Some LEDs produce a near point-source of light and it’s necessary to use a reflector-lens with each LED to capture the luminous energy and direct it to the area to be photographed.  These small reflector-lenses are computer designed for the physical characteristics of each type of LED, resulting in the greatest possible collection efficiency at various beam angles.

However, as with typical conventional lighting fixtures, there is a compromise of balancing luminous intensity and beam angle.   As with most reflectors, the light beam diverges to cover a larger area as the distance between the LEDs and the subject is increased.  Unlike traditional tungsten-halogen or HMI light fixtures with single lamps, multiple LEDs are usually packaged within a single fixture of 3 to 50 LEDs (or more) with each LED having its own precision reflector.  Various LED arrays are packaged to produce both spot and flood illumination using different reflectors of 5° to 45° beam angles.  In each case near constant intensity is maintained across the beam by overlapping the outer beam of each LED to its adjoining LED in a “daisy chain” effect.  The result is a smooth continuous light beam at a color temperature of 6000° Kelvin with a distinct intensity decrease (or fall-off) near the edge of the beam.  

 The luminous efficiency of the following LED arrays is further enhanced by a selection process that matches each LED for: 1) brightness 2} color temperature and 3) voltage drop.  This procedure virtually eliminates beam artifacts like hot-spots, rings, halos and color variations.  

Users should select LED arrays with the beam angle best suited for the imaging task and avoid spilling lighting light outside the camera’s field-of-view.  In most applications high-speed imaging requires very high intensity illumination that can easily exceed bright sun-light, which is a nominal 10,000 foot-candles or 107,600 lux.  

The following family of LED arrays is powered by constant current DC voltage drive controllers.  To further enhance LED performance and reduced power consumption, each controller uses a series/parallel circuit design, which reduces current consumption by a nominal 66% while retaining the maximum rated luminous output of each LED.   All controllers include 3-switchable intensity levels: 1) modeling light at 25% of normal  2) normal at 100% and  3) maximum at 125% of normal.   AC powered controllers operate on 100-240VAC 50/60Hz and DC controllers require 12 or 28 VDC power depending on the number of LEDs in each array.   In addition to continuous light controllers, combination controllers for both stroboscopic and continuous light are also available.

 A single LED module, model 200800, is very useful in restricted areas where space is limited.  Or, in other circumstances the beams of multiple single LEDs can be super-impose to build illumination levels beyond 10,000 foot-candles, resulting in a small circle of light of 2-inches or less with virtually no heat in the beam.

The LED arrays illustrated in the following photos are ruggedized and suitable for Hi-g shock and vibration environments:   Automotive crash and sled testing, airborne, military, scientific laboratory applications machine vision.   If additional information is needed please refer to our technical data sheets for detailed specifications. 

24 LED Ring Light

Model 200845

Specifications:

Large 4x6 LED Array

Model 200835

Specifications:

Small 4x6 LED Array

Model 200830

Specifications:

2X12 LED Linear Array

Model 200840

Specifications:

3x4 LED Array

Model 200825

Specifications:

3x3 LED Array

Model 200820

Specifications:

2x2 LED Array

Model 200810

Specifications:

3 LED Array

Model 200815

Specifications:

Single LED Lights

Model 200800

Specifications:

                   6 Single Lights shown for illustration only

Single LED Light with 

Optical Fiber Light Guide

Model 200790

Specifications:

Dual Channel LED Arrays with

 Ruggedized Controller

Model 201500 System with

Dual Model 201530 LED arrays

The 201500 is a dual channel self-contained Hi-g LED controller.  It includes two 12-volt batteries that power a pair of 4 x 6 white or red LED's.  A pair of 25-foot (7.65m) power cables connects the controller to the LED arrays.

This controller is designed for remote control operation at distances of 500 feet or more.  It accepts a TTL active low remote voltage or contact closure to activate both 4 x 6 LED arrays.  A buffered output is also provided to trigger additional controllers.  This controller is highly ruggedized and ideal for Hi-g sled, field and explosive environments.  The remote input is also compatible with wireless interface.

The controller’s timer circuit has four switch positions with 3 On-Time durations: 15, 30 and 45 seconds.  Position 1 allows instant ON-OFF control.   The time durations automatically switch off the LED's when the selected duration times-out.  Note that the LED's remain on, even if the remote control cable is severed or damaged.  These durations are also factory programmable for other time intervals.

Specifications

Construction:

Heavy-duty steel enclosure

Size:

6.5"H x 8"W x 10"L (17 x 20.5 x 26cm)

Weight:

23 Pounds (11Kg)

Battery Test:

Displays battery voltage

Charger:

two Model C12-B supplied with each controller