Northern Airborne Technology LD12 User Manual

Part of

SM15

LD12

Lamp Dimmer

INSTALLATION and OPERATION MANUAL

REV 4.00 November 21, 2003

Northern Airborne Technology Ltd.

1925 Kirschner Road
Kelowna BC, Canada

V1Y 4N7

Telephone [phone]

Facsimile [phone]

Copyright 2003 by Northern Airborne Technology

CONFIDENTIAL AND PROPRIETARY TO NORTHERN AIRBORNE TECHNOLOGY LTD.

SM15 Rev 4.00 LD12 Lamp Dimmer Manual

Periodically NAT will release manual amendments. In order to maintain the most
accurate and up to date manual these amendments should be carried out immediately
upon receipt and recorded on the following amendment record.

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Nov 21, 2003 Page ii

ENG-FORM: 820-0109.DOT

CONFIDENTIAL AND PROPRIETARY TO NORTHERN AIRBORNE TECHNOLOGY LTD.

SM15 Rev 4.00 LD12 Lamp Dimmer Manual

Table of Contents

Section Title Page

1.0 Description

1.1 Introduction 1-1

1.2 Purpose of Equipment 1-1

1.3 Features 1-1

1.4 Specifications 1-1

1.4.1 Electrical Specifications 1-1

1.4.2 Physical Specifications 1-2

1.4.3 Environmental Specifications 1-3

2.0 Installation

2.1 Introduction 2-1

2.2 Unpacking and Inspection 2-1

2.3 Installation Procedures 2-1

2.3.1 Warnings 2-1

2.3.2 Cautions 2-1

2.3.3 Notes 2-2

2.3.4 Cabling and Wiring 2-2

2.3.5 Installation Variations 2-2

2.3.6 Optional Dimmer Adjustment 2-3

2.3.7 Optional Emergency Bypass Switch 2-3

2.3.8 Post-Installation Checks 2-3

2.4 Continued Airworthiness 2-4

2.5 Installation Drawings 2-4

3.0 Operation

3.1 Introduction 3-1

3.2 Operation 3-1

Nov 21, 2003 Page iii

ENG-FORM: 820-0109.DOT

CONFIDENTIAL AND PROPRIETARY TO NORTHERN AIRBORNE TECHNOLOGY LTD.

SM15 Rev. 4.00 LD12 Lamp Dimmer Manual

Section 1.0 Description

1.1 Introduction

This manual contains information on the LD12 Lamp Dimmer.

Information in this section consists of purpose of equipment, features and specifications.

1.2 Purpose of Equipment

The LD12 is a remote mounted light dimmer module, designed for complicated
annunciator requirements in Loran / GPS systems. The unit is capable of controlling 12
independent lamps with full test function. In its basic mode of operation, the LD12 can
be used as a bulk lamp dimmer, outputting up to 1 amp of current. The LD12 unit can
be easily interfaced with all NAT RS-series remote switch products used in Loran / GPS
installations.

1.3 Features

Internal logic is provided to interface to both the floating lamp connections of the PB08,
and annunciators triggered by a ground output. An adjustable lamp dimmer is provided
to drive twelve separate 28 Vdc/50 mA lamp lines.

The dimmer may be operated in the preset mode (typically set in the 12-24 V range), or
as an adjustable dimmer via an external control. A single switch can be used to select
day, night, and lamp test functions.

The day operation mode also provides regulated 24 Vdc for all lamps, to prevent early
lamp failure and internal lamp blackening from excessive voltage.

All interconnect and relay contacts are gold plated. Relays are sealed, high vibration
rated (50 g shock), dry nitrogen filled units.

Circuit boards are constructed of G10-FR (flame retardant) material, with solder masks,
reflowed tin plating, and environmental post-coating.

Nov 21, 2003 Page 1-1

ENG-FORM: 800-0106.DOT

CONFIDENTIAL AND PROPRIETARY TO NORTHERN AIRBORNE TECHNOLOGY LTD.

LD12 Lamp Dimmer Manual SM15 Rev. 4.00

1.4 Specifications

1.4.1 Electrical Specifications

Input Power +24.8 Vdc to +30 Vdc, +27.5 Vdc nominal

(reverse and over voltage protection)

Input Current 50 mA idle (2 A max.)

Inputs:

Test Keyline Active low input. Grounding this pin will cause

all lamps to illuminate at full brightness. This
feature allows the user to check for faulty
filaments.

Dimmer Active low input. Grounding this pin will cause

the internal preset dimmer voltage to be
supplied to all lamps.

Dimmer GND Provides a convenient ground return for the

dimmer controls.

Lamp Pwr In Direct connection to internal lamp bus.

Lamp Keys Active low keyline. Grounding this pin will

cause the selected lamp to illuminate. Current
drawn will depend on type of lamp used in
circuit. Pin should be left open when unused.

Outputs

Lamp Outputs 0 mA to 50 mA of current to 2 floating lamp

circuits and 10 ground keyed circuits for system
annunciators. Recommended lamps: Type 327,
387 or 388 for 28V operation @ 40 mA each.

Dimmer Out Direct connection to dimmer circuit output.
Provides up to 1 A of current.

Page 1-2 Nov 21,2003

ENG-FORM: 800-0106.DOT

CONFIDENTIAL AND PROPRIETARY TO NORTHERN AIRBORNE TECHNOLOGY LTD.