Part documentation for the 2SD1631, a 162 KB PDF listed as a schematic. JIS designation 2SD indicates an NPN bipolar transistor designed for low-frequency or power circuits. Expect sections on absolute maximum ratings, hFE grouping, switching or frequency data and package dimensions. Technicians consult it before replacing a failed device, confirming terminal order and comparing equivalents. The printed marking on the transistor is often shortened to D1631, so check it carefully against this sheet before ordering parts.
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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