BA11-A Mounting Box and Power System Technical Manual

This technical manual provides comprehensive information on the BA11-A Mounting Box and its Power System, designed for the PDP-11/44 and other PDP-11 processors.

The document details the BA11-A mounting box as an enclosure for the processor's backplane, incorporating an H7140 power supply and cooling fans, and its ability to be slide-mounted or cabinet-mounted. It also covers the optional H7750 battery backup unit, which provides DC refresh power to MOS memory and maintains fan operation during AC power failures, using sealed lead-acid batteries. The 872-D, -E power controller, responsible for AC power distribution and control within the system, is also described.

The manual is structured into four main sections:

1. Introduction: Provides a general overview, physical description of the BA11-A and its components (H7140 power supply, H7750 battery backup unit), and lists related documentation.
2. Installation: Offers procedures for unpacking, mounting the BA11-A (in various cabinet types or on slides), configuring AC power connections, and installing the optional power controller and battery backup unit.
3. Functional Operation: Explains how the H7140 power supply generates various DC voltages for logic and memory modules, provides fan power, and describes the control signals involved. It also details the functional aspects of the 872-D, -E power controller (AC distribution, safety features) and the H7750 battery backup unit (power provision during AC failure, charging mechanisms).
4. Service: Contains guidelines for power checks, troubleshooting, and comprehensive removal and replacement procedures for the BA11-A mounting box, H7140 power supply, fan assembly, and CPU backplane, along with component location diagrams for maintenance.