Northern Airborne Technology LD12 - Manual (Page 7)

SM15 Rev. 4.00 LD12 Lamp Dimmer Manual
Nov 21, 2003 Page 1-1
ENG-FORM: 800-0106.DOT
CONFIDENTIAL AND PROPRIETARY TO NORTHERN AIRBORNE TECHNOLOGY LTD.
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.