51904 \(Clear Lens\)This specification covers the performance requirements for hermetically-sealed red discrete and panel mount light emitting diodes. Two levels of product assurance are provided for each device type as specified in MIL┬ûPRF┬û19500.

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MIL�PRF�19500/519E

6.5.1 Design considerations. Design consideration should include: Ambient light level and color; viewing

background, color and texture; observer, attentiveness, position and operator accessories (glasses, goggles). Where

ambient light levels are so high that it is difficult to distinguish between the LED on condition and glint (reflection of

light from the surface of the LED lens), a modulated current causing a visible flicker in the LED at 10 Hz is

recommended. Color filters, louvered filters, and circular polarizing filters may enhance the desired visual effects of

the LED. For applications in bright sunlight, sunlight viewable types are recommended. With the proper

enhancement filter, these parts are readable in sunlight ambient conditions.

6.6 Reliability considerations. There is a correlation between LED luminous intensity degradation and operating

current levels. To lengthen the useful life of this device, drive current should be held to a minimum consistent with

use conditions. Luminous intensity would have to change by more than 50 percent before becoming apparent to the

causal observer.

6.7 Replacement data. Device types JANM19500/51901 and JANTXM19500/51902 are direct replacements for

device types M19500/519-01 and M19500/519-02, respectively.

6.8 PIN examples.

6.8.1 Through-hole mount devices. The PIN for encapsulated devices are in the following form.

JANTX

6609

JAN brand and quality level

Component designation

Identification number

6.8.2 Panel mount assemblies. The PIN for panel mount assemblies are in the following form.

JAN

M19500/519

JAN brand and quality level

Specification designation

Identification number

6.9 Changes from previous issue. The margins of this specification are marked with vertical bars to indicate where

changes from the previous issue were made. This was done as a convenience only and the Government assumes no

liability whatsoever for any inaccuracies in these notations. Bidders and contractors are cautioned to evaluate the

requirements of this document based on the entire content irrespective of the marginal notations and relationship to

the last previous issue.