LDM
This video shows technical details of an aircraft instrument manufactured by Spirent in the 90's. This instrument is an EPR indicator, Engine Pressure Ratio. On this first episode there are two sections. The first one shows the internal construction. The second section shows the complete schematic diagram with explanations.
The second episode will show the code disassembly and I hope the complete test of this unit using an ARINC429 test generator.
00:00 - Intro
01:05 - Teardown
02:54 - Interface board
03:35 - MPU board
04:57 - Power supply and stepper motors driver board
06:43 - Display board
07:40 - Preliminary test
10:15 - Display test
Reverse engineering:
10:50 - MPU board
12:27 - ARINC429 Interface Board
15:50 - Luminosity control
17:39 - Power down detection
18:15 - Display board
Schematic diagram:
https://mwblog.fr/wp-content/uploads/...
Blog:
https://mwblog.fr/ldm-375-boeing-727-...