G9341

This document is a proprietary schematic diagram and associated documentation from Digital Equipment Corporation, copyrighted in 1971, for their TU-10 Brake Actuator. It is intended solely for test and maintenance purposes.

The main part of the document presents the electronic circuitry for controlling the Lower Brake and Upper Brake mechanisms. It also incorporates signals related to Reel Motor Pulse, Reel Motor Enable, Data Load Pulse, and Low Rewind Brake, indicating its role in managing tape reel movement and braking functions. The circuit operates on +18V, -18V, and +5V power supplies and is constructed using a variety of discrete components, including numerous transistors (e.g., DEC6531, DEC6534, DEC3791, DEC4923), various diodes (e.g., D672, 1N748A, 1N756A), resistors, and capacitors.

A separate diagram in the lower-left section appears to illustrate the physical interconnection or layout of certain components (Q1-Q11) within the actuator.

The document also includes a comprehensive Bill of Materials (parts list), detailing all components used with their descriptions, quantities, and specific part numbers. Additionally, a Transistor & Diode Conversion Chart is provided, cross-referencing Digital Equipment Corporation's internal part numbers with their EIA or other industry-standard equivalents.