This video documents the initial teardown of a vintage military avionic unit, an "Automatic Control Unit Air Intake Control System" manufactured by Nord Micro Frankfurt. The unit, featuring components with date codes from the late 1970s and early 1980s, is characterized by its robust, modular construction and the extensive use of a thick, yellowish silicone-like conformal coating for environmental protection.
The internal electronics consist of multiple circuit boards with a mix of analog and digital technologies. Digital sections are built with TTL 54-series logic ICs, while analog circuits employ LM101 operational amplifiers, military-specification (JANTX) transistors, and highly stable metal foil resistors. The core functional components identified are the advanced resonating cylinder pressure transducers, manufactured by Micro Tecnica Torino. These sensor modules each contain a dedicated PCB with a PROM for calibration data and an integrated diode for temperature compensation. The teardown also reveals a substantial linear power supply unit featuring a toroidal transformer and multiple power transistors on a large heatsink.
Teardown of a Military Avionic Air Intake Control Unit
0:00 Introduction to the Unit: The video introduces a large avionic device, an "Automatic Control Unit Air Intake Control System" from a military aircraft, manufactured by Nord Micro.
0:45 Circuit Board Construction: The internal electronic boards are covered in a thick, yellowish, silicone-like conformal coating for protection against vibration and moisture.
1:02 Vintage Electronics: The boards contain a mix of 1970s/80s technology, including TTL 54-series digital logic ICs, LM101 op-amps, and JANTX military-specification transistors.
1:53 High-Precision Components: The analog circuitry utilizes highly accurate and stable metal foil resistors, noted for having a very low temperature coefficient of around 1-3 ppm per degree Celsius.
5:14 Resonating Pressure Sensors: The system's primary sensors are identified as resonating cylinder pressure transducers, manufactured by Micro Tecnica Torino, Italy, with a 1982 date code.
5:55 Sensor Operation and Calibration: These advanced sensors measure pressure by detecting changes in the oscillation frequency of an internal mechanical cylinder. Each sensor module includes an onboard PROM, likely containing specific calibration data.
6:51 Temperature Compensation: The pressure measurement is corrected for temperature using a diode located inside the sensor assembly. The presence of this diode is confirmed by measuring its 0.62V forward voltage drop.
7:47 Robust Linear Power Supply: A dedicated module houses a multi-output linear power supply. Key components include a large heatsink, several military-spec power transistors (like the 2N3771), and a toroidal main transformer.
10:08 To Be Continued: This teardown is the first part of a series. The next video will focus on attempting to power up and operate one of the pressure transducers.