Handbook
Table Of Contents
- AMENDMENT LIST RECORD SHEET
- INTRODUCTION
- 1.SAFETY CONSIDERATIONS
- 2.OVERVIEW/SYSTEM DESCRIPTION
- 3.SPECIFICATION
- 3.150-063701 Parts Lists
- 3.1.1Base Antenna Side UHF Duplex/PA Shelf 50-063702 Parts List
- 3.1.2Downlink UHF 5 Channel Shelf 50-063703 Parts List
- 3.1.3Uplink UHF 4 Channel Shelf 50-063704 Parts List
- 3.1.4Tunnel side UHF Duplex/PA Shelf 50-063705 Parts List
- 3.1.5UHF Simplex Shelf 50-063706 Parts List
- 3.1.6Power Supply Shelf 50-063707 Parts List
- 3.2Technical Specification
- 3.3Mechanical Specification
- 3.150-063701 Parts Lists
- 4.SYSTEM DRAWINGS
- 4.1Drg. No. 50-063751, Channelised Cell Enhancer Rack Layout Drawing
- 4.2Drg. No. 50-063781, Channelised Cell Enhancer System Diagram
- 4.3Drg. No. 50-063792, Base Side Duplex Shelf Outline Drawing
- 4.3Drg. No. 50-063793, Downlink Channels Shelf Outline Drawing
- 4.4Drg. No. 50-063794, Uplink Channels Shelf Outline Drawing
- 4.5Drg. No. 50-063795, Tunnel Side Duplexer Shelf Outline Drawing
- 4.6Drg. No. 50-063796, UHF Simplex Shelf Outline Drawing
- 4.7Drg. No. 50-063797, Power Supply Shelf Outline Drawing
- 5.SUB-UNIT MODULES
- 5.1UHF Duplex Shelf 50-063702
- 5.25 Channel UHF Downlink Shelf 50-063703
- 5.3UHF Uplink 4 Channel Shelf 50-063704
- 5.4UHF Duplex/PA Shelf 50-063705
- 5.5UHF Simplex Channel Shelf 60-063706
- 5.6Power Supply Shelf 50-063707
- 6.INSTALLATION
- 7.MAINTENANCE
- APPENDIX AINITIAL EQUIPMENT SET-UP CALCULATIONS
Denver Channelised CE
User/Maintenance Handbook
Handbook Nō.-50-063708HBKM Issue No:-2
Date:-03/11/2003
Page:-
38 of 51
5.2.3 Dual DC/DC Converter (13-001803)
5.2.3.1 Description
This unit is employed where it is necessary to derive two fixed voltage power supply rails
from some higher voltage. Typically it is used to derive 5, 8, 12 or 15V from a 24V input.
The circuit is based upon a pair of LM257 series variable voltage regulators (LM2576, 12
& 15V & LM2575, 5V), which are each capable of supplying an absolute maximum of
1.5A output current. Note that at full output current, the dissipation of the device must
remain within design limits, bearing in mind the voltage which is being dropped across it.
The maximum allowable dissipation will also depend on the efficiency of the heatsink on
which the device is mounted.
5.2.3.2 Technical Specification
PARAMETER SPECIFICATION
Operating Voltage: 21 – 27V DC
Output Voltage: 12V & 12V (typical)
Output Current: 1.0A (maximum per o/p)
Connections: Screw Terminal Block
operational:
-30ΒC to +60ΒC
Temperature
Range
storage
-40ΒC to +70ΒC
PCB Size: 85 x 63mm