A 190 KB PDF holding the data document for the 2SB1640 transistor, indexed under schematics. The JIS 2SB prefix means a PNP bipolar device for low-frequency applications; package and manufacturer are not part of the file name. Repair technicians rely on such sheets to check pin order, saturation voltage, collector current capacity and power dissipation when a transistor in a supply or driver stage has failed short or open. Always match the package outline and gain class rather than relying on the number alone.
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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The standard format for schematics, block diagrams, power-sequence charts and service manuals.