5-Slot Power Supply Operation - Data General NOVA 4/C Field Engineering Maintenance Manual

Data General Corporation (DGC) has prepared this manual for use by DGC personnel and customers as a guide to the proper installation, operation, and
maintenance of DGC equipment and soft ware. The drawings and specifications contained herein are the property of DGC and shall neither be reproduced in whole or
in part without DGC's prior written approval nor be implied to grant any license to make, use, or sell equipment manufactured in accordance herewith.
Chapter 10
5-SLOT POWER SUPPLY OPERATION
INTRODUCTION
The NOVA 4 5-slot power supply converts a 100/120 or
220/240 ac voltage power source to the five regulated dc
voltages required by the NOVA 4 computers. It also
generates the system clocks. A battery backup option
generates the regulated dc memory voltages from a +6
volt battery during an ac power failure.
option and battery, is contained on a single printed circuit
system clocks to the printed circuit boards via the
backpanel and provides ac power for the fan modules via
A line cord with a 12-pin connector is used to determine
designators (e.g., C1 and T1) refer to the 5-slot power
supply logic schematic, DGC No. 001-001616. Thus
when reading this chapter, it is helpful to refer to the
ORGANIZATION
The 95-slot power supply, like the 16-slot power supply,
uses a forward off-line switching regulator to produce the
high power outputs required by the NOVA 4 computers.
The major components of the 5-slot power supply's off-line
switching regulator are a VNR source, a pulse width
modulation control, an inverter, and a dc regulator.
In addition to the off-line switching regulator, the 5-slot
power supply includes a line filter, an auxiliary voltage
supply, soft start logic, several voltage regulators, various
fault detection circuits, and the system clock circuitry.
Figure 10.1 shows the interconnection of all these
components.
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