This part is a kind of semiconductor called IL5.
Function of this product has PHOTOTRANSISTOR OPTOCOUPLER.
Manufacturers : Siemens Semiconductor Group
Image and pinout :
Some of the text within the PDF file :
IL1/2/5 PHOTOTRANSISTOR OPTOCOUPLER FEATURES • Current Transfer Ratio at IF=10 mA IL1, 20% Min. IL2, 100% Min. IL5, 50% Min. • High Collector-Emitter Voltage IL1 – BVCEO=50 V IL2, IL5 – BVCEO=70 V • Field-Effect Stable by TRansparent IOn Shield (TRIOS) • Double Molded Package Offers Isolation Test Voltage 5300 VACRMS • Underwriters Lab File #E52744 V • VDE Approval #0884 (Available with Option 1) D E Dimensions in inches (mm) Pin One ID 3 .248 (6.30) .256 (6.50) 4 5 6 2 1 Anode 1 Cathode 2 NC 3 6 Base 5 Collector 4 Emitter .335 (8.50) .343 (8.70) .039 (1.00) Min. 4° typ. .018 (0.45) .022 (0.55) .300 (7.62) typ. .130 (3.30) .150 (3.81) 18° typ. .020 (.051) min. .031 (0.80) .035 (0.90) .100 (2.54) typ. .010 (.25) .014 (.35) .300 (7.62) .347 (8.82) .110 (2.79) .150 (3.81) [ ... ]