PDF datasheet for the 4N35 optocoupler, marked as revision 2 in the file name and about 276 KB in size. The 4N35 is a widely used phototransistor-output isolator that appears in SMPS feedback circuits, mains-isolated signal paths and microcontroller interfaces. During repair it helps confirm which pins carry the LED anode, cathode, collector and emitter, and what transfer ratio to expect when testing with a diode meter. Later revisions may differ slightly, so check against the manufacturer printed on the chip.
The button opens the matching file on RM Schematics, or a source page if it is not catalogued there yet. The original attachment is from @cyberlanelectonik. Enginerys does not host this file.
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