Le labo de MichelThis video shows the teardown and tests of an ADI-70 manufactured by Collins. Preliminary tests are performed using a synchro transmitter. Final tests are performed using the same synchro transmitter and a MK VI GPWS in order to test the "Bank Angle" aural warning message.
00:00 - Intro 02:00 - Teardown 06:05 - First tests using a synchro transmitter 07:52 - Final test with MK VI GPWS
LDM #199: Teardown and Tests of a Collins Attitude Director Indicator ADI-70Le labo de Michel2021-08-12 | This video shows the teardown and tests of an ADI-70 manufactured by Collins. Preliminary tests are performed using a synchro transmitter. Final tests are performed using the same synchro transmitter and a MK VI GPWS in order to test the "Bank Angle" aural warning message.
00:00 - Intro 02:00 - Teardown 06:05 - First tests using a synchro transmitter 07:52 - Final test with MK VI GPWSLDM #380: Kollsman CPU-46/A-22 Military Computer - Part 1: teardown and reverse engineeringLe labo de Michel2024-10-09 | This video shows the teardown and the reverse engineering of a Kollsman CPU-46/A-22 Computer used in military aircraft RF-8G and F-8J/K/L. This vintage electro-mechanical computer permits the computation of the altitude. A correction of the static port according to the Mach number is present.
00:00 - Intro 01:43 - Teardown 06:13 - Dual synchro system 06:48 - Reverse engineering : dual synchro system 08:44 - Static Source Error Correction (SSEC) 11:35 - Mach number computation and SSEC cam 14:29 - Output synchro and digitizer 15:22 - Servo monitor circuits
Schematic diagram: https://mwblog.fr/wp-content/uploads/2024/10/CPU-46.pdfLDM #379: Teardown of a vintage Honeywell 3 Axes systemLe labo de Michel2024-09-28 | 00:00 - Intro 01:01 - Teardown 04:09 - Electronic boards 06:43 - Electronic time interval generator 13:30 - Programming panel 15:58 - Analog boardsLDM #378: ДЛУММ-30 (DLUMM-30) Servo AccelerometerLe labo de Michel2024-09-19 | Errata: the range of this accelerometer is +/-30g not +/-20g as I said in the test section at 11:05. Therefore an acceleration of +/-1g corresponds to an output voltage of +/-0.167V.
00:00 - Intro 01:11 - Teardown 02:13 - First analysis 04:17 - Electronic boards 05:29 - Reverse engineering 07:40 - Test coils 08:46 - Faulty detector 11:05 - Bypassing the faulty detector 11:23 - Test
This videos shows technical details about a Russian servo accelerometer ДЛУММ-30 (DLUMM-30). This accelerometer was installed inside a 9E420 radar seeker.
How it works: A mass translates the acceleration into a torque which is balanced by a second torque generated by two coils. A sensitive zero detector detects any deviation of the moving mass from the zero position. The resulting voltage is amplified and fed to the torque generator, keeping the mass at the same zero position. The zero detector uses two variable transformers. The primaries are supplied with an ac voltage at 830 kHz. A small piece of copper mechanically linked to the moving assembly penetrates between the primary and the secondary, which modifies the differential induced voltage.
Schematic diagram:LDM #377: ДУСУ1-30В (DUSU1-30V) Russian angular rate gyro - Part 1Le labo de Michel2024-09-14 | 00:00 - Intro 01:00 - Draining the damping oil 02:04 - Opening the gyro 03:48 - Torque motor 06:44 - Test setup 07:28 - First testLDM #376: Jaeger Fuel Flow Indicator - Teardown, test and reverse engineeringLe labo de Michel2024-09-04 | This video shows the teardown and the test of a fuel flow indicator P/N 65691-005-1 manufactured by the French company Jaeger in the 80s. The last part shows the schematic diagram with explanations.
00:00 - Intro 00:40 - Teardown 02:45 - Power Supply board 03:15 - Servo Amplifier board 03:31 - Fuel flow rate and logic board 05:58 - Test 08:45 - Reverse engineering - Part 1: analog display 10:25 - Digital input circuit 11:44 - Gate and averaging circuits 13:11 - FF rate and display update rate 15:51 - Counters reset signal 16:24 - Scrolling detection 17:40 - Counters and display 19:34 - Clock generator
Connector pinout:
A-B: Lighting, 5Vrms D-K: 115Vac 400Hz J: input common H: analog input, 0 to 5V C: digital input, 2.27Hz square wave for 1,000. Display proportional to input period. Hi level 6V min.
How it works: There are 2 two separate inputs. The first one is a DC voltage from 0 to 5V which permits to set the needle between 0 and 12,000 kg/h. Its uses a torque motor with an embedded potentiometer for the feedback. A servo amplifier permits to set the needle according to the input voltage. The second input is a square or rectangular signal. The clock signal is fed to three CD4518 counters gated by the input signal. An averaging of 10 is performed by counting 10 input cycles and by dividing the counts by 10. A the end of the counting a load signal permits to update the coding wheels display. The display rate depends on the rate of change of the fuel flow. A differentiator is used to get an image of the variation of the fuel flow with time. This signal is fed to a Voltage Controlled Oscillator which gives the maximum update rate of the display. The rightmost digit scrolls when there is a variation of the fuel flow.
Schematic diagram: https://mwblog.fr/wp-content/uploads/2024/09/Jaeger_FF_Indicator_A.pdfLDM #375: Boeing 727 EPR Indicator - Part 1: Teardown and Reverse engineeringLe labo de Michel2024-08-28 | 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
Blog: https://mwblog.fr/ldm-375-boeing-727-epr-indicator-part-1-teardown-and-reverse-engineering/LDM #374: Humphrey directional gyro - teardown, test and reverse engineeringLe labo de Michel2024-08-22 | In this video I study and operate a vintage directional gyroscope DG11-0105-1 manufactured by Humphrey Inc., San Diego, California. The heading is slaved to a flux detector connected to the gyroscope. A test is performed using an HSI Collins 331A-8K.
00:00 - Intro 00:40 - Teardown 03:34 - First test and gyro precession 04:50 - Final test with magnetic compass and Collins HSI Reverse engineering: 06:32 - Part 1: overview 07:12 - Part 2: power supply 07:44 - Part 3: inner gimbal horizontal stabilization 08:48 - Part 4: input filter 10:53 - Part 5: amplifier and phase detector 12:29: Part 6: high speed slaving 13:27: Part 7: reference signals generator
Schematic diagram : https://mwblog.fr/wp-content/uploads/2024/08/DG11-0105-1.pdf Blog: https://mwblog.fr/?p=804&preview=trueLDM #373: analysis of a 9E420 Radar seeker electronic boardLe labo de Michel2024-08-15 | After some researches this board is used in a 9E420 radar seeker: ausairpower.net/PVO-SV/9M317E-Buk-M2E-9E420+Slantets-1S.jpg This board is probably involved in the servo control of the antenna position.
00:00 - Intro 01:57 - Inside the shield 02:47 - Reverse engineering 04:07 - Attenuators 04:36 - Amplifiers and bad guarding tracks 05:44 - Analog switch control 05:58 - Colpitts oscillator 07:15 - Oscillator test
Schematic diagram in pdf: https://mwblog.fr/ldm-373-analysis-of-a-kh-101-missile-electronic-board/LDM #372: Fiber Optic Gyro ТИУС500 and Tornado-S missile IMULe labo de Michel2024-08-09 | This video shows some details about the Russian Fiber Optic Gyro ТИУС500 (TIUS500) which was described in the second part of the video #356. The first part of this video shows briefly the FOG installed in the gyro assembly of a Tornado-S Russian missile. The second part of the video shows the schematic diagram with explanations obtained after three days of reverse engineering.
Schematic diagram and blog: https://mwblog.fr/ldm-372-fiber-optic-gyro-and-tornado-s-missile-gyro-assembly/LDM #371: Boeing 727 EGT IndicatorLe labo de Michel2024-08-01 | 00:00 - Intro 00:38 - Teardown 05:21 - Test 08:01 - Piecewise amplifier 11:30 - Reverse engineering 11:41 - Power Supply 12:10 - Reference voltages 12:35 - Main circuits 13:00 - Front-end amplifier 14:21 - Piecewise Amplifier circuits
Connector Pinout: 1-2: Lighting 5Vrms 3-4: 115Vac 400Hz 5: Thermocouple (-) 6: Thermocouple (+) 7: Mechanical groundLDM #370: Boeing 757 standby engine instrument - Teardown, reverse engineering and testLe labo de Michel2024-07-25 | This video shows the teardown and test of a Boeing 757 cockpit standby engine instrument, model S231n001 manufactured by General Electric. The schematics with explanations are given at the end of this video.
00:00 - Intro 01:17 - Teardown 02:29 - EGT board 04:05 - Cold junction compensation 05:37 - EPR board 06:47 - N2 board 08:27 - N1 board 08:45 - Tests 11:34 - Self-test 12:00 - Reverse engineering: PS board 12:39 - Reverse engineering: EGT board 16:49 - Reverse engineering: N2 boardLDM #369B: Shahed-136 drone - Air Data Computer Pressure sensorLe labo de Michel2024-07-19 | This video shows some details regarding the pressure sensors used in the air data computer described in video #369
Part 1: youtu.be/PI8aGYTlvJQLDM #369: Shahed-136 drone Air Data Computer moduleLe labo de Michel2024-07-12 | This video shows the analysis of the air data computer used in the Shahed-136 kamikaze drone.
00:00 - Intro 00:05 - Board overview 01:50 - Preliminary test 02:27 - Reverse engineering 03:36 - Test
Blog and schematics: https://mwblog.fr/ldm-369-shahed-136-drone-air-data-computer/LDM #368: Sperry AD-300C Attitude Director Indicator - Teardown and testLe labo de Michel2024-07-03 | This video shows the teardown and test of an Attitude Director Indicator model AD-300C manufactured by Sperry.
00:00 - Intro 00:56 - Teardown 02:25 - No gear train 02:50 - Test 05:53 - Attitude circuits modular circuit
Notes: * This ADI uses a DC motor for the roll control and a torque motor for the roll * There is no gear train, the motors are directly linked to the gimbal for the roll and to the sphere for the pitch. This permits to save some weight and cost, the counterpart is the lack of stability when quick change of pitch or roll accurs. However this shouldn't be a problem with commercial aircraft. * The electronics use mainly potted modules
Pinout: 26-27-28: roll synchro input 29-30-31: pitch synchro input 10: 28V attitude enable signal (from vertical gyro)LDM #367: Shahed-136 kamikaze drone servomotorLe labo de Michel2024-06-22 | This video shows the teardown, the reverse engineering and the test of a servomotor used in the Iranian Shahed-136 kamikaze drone (also called Geranium-2) . 00:00 - Intro 01:46 - Teardown 02:36 - Electronic board 03:16 - Test 06:15 - Reverse-engineering - overview 06:47 - Reverse polarity protection 08:15 - Power supply 08:54 - Brushless motor power stage 10:03 - PWM input interface 10:27 - Feedback device 10:46 - Feedback output circuit
Blog: https://mwblog.fr/ldm364/LDM #365: Atlas launcher gyro part 3: demodulator reverse engineering using X-ray Cheetah EVOLe labo de Michel2024-05-19 | This video shows the reverse engineering of the demodulator module of a vintage gyro subsystem GR 10A-1 manufactured in 1965 and designed for an Atlas Launch Vehicle.
Merci à la société Inovelec pour avoir consacré un peu de temps à l'inspection aux rayons X de ce module, ce qui m'a permis d'effectuer la rétroingénierie de celui-ci. inovelec-groupe.com
Other episodes: youtu.be/Y11XXXc7LKY youtu.be/_EgoEV346tYLDM #364: Aircraft Coffee Maker Part 1: overviewLe labo de Michel2024-05-13 | This video shows the internals of an a coffee maker used in Boeing and Airbus aircraft. 00:00 - Intro 00:45 - Front panel 02:29 - Heaters and possible modifications for 115/230 50/60 Hz 05:18 - Electronic boardsLDM #363: Atlas launcher gyro part 2: synchros and spinning testLe labo de Michel2024-05-08 | 00:00 - Intro 00:03 - Outer gimbal synchro test 01:02 - Inner gimbal synchro test 02:00 - Slip ring contact pinout 04:48 - Gyro rotor spinning testLDM #362: Atlas Launch Vehicle Attitude Reference Subsystem Gyro - Part 1: teardownLe labo de Michel2024-04-27 | This video shows the teardown of a vintage gyro subsystem GR 10A-1 manufactured in 1965 and designed for an Atlas Launch Vehicle.
00:00 - Intro 03:25 - Teardown 05:51 - Draining the oil 08:48 - Gimbals resolvers and torque motorsLDM #361: Analysis of a military electronic boards assemblyLe labo de Michel2024-04-12 | This video shows the analysis and reverse engineering of an electronic assembly which was supposed to be inside a Ukrainian "Stugna-P" missile launcher. One board contains an Atmel ATMEGA168 micro-controller which is connected to a MEMS rate gyroscope and one MEMS accelerometer. The gyroscope is soldered on a small pcb which is mounted on a small mechanical assembly. The angle of the gyroscope can be adjusted using two screws. Another board permits the servo control of the position of something linked to a brushless motor.
00:00 - Intro 02:04 - Gyro and accelerometer processing board 04:45 - Interface / DSP / CPU board 03:36 - Brushless motor servocontrol 05:39 - Reverse engineering: MEMS Gyro assembly 06:04 - MEMS Accelerometer 06:28 - Microcontroller Atmega168 07:12 - Ribbon cable interface 08:04 - Servo control board overview 08:49 - MC33035 Brushless DC motor controller 10:15 - DAC circuits 11:27 - Summing amplifier and phase correction 12:47 - Absolute value circuitLDM #360: Reverse engineering of a Russian missile electronic board #1Le labo de Michel2024-03-22 | This video shows the reverse engineering of a Russian electronic board. The reference of the board is "TDCK". It is the power supply board of a satellite communication receiver used in several Russian missiles. We can can this receiver in a Tornado-C missile for instance (Торнадо-С). Video: youtu.be/xJyV7AGPT_4?si=R-ju1wXSOHIxuqTy&t=198
00:00 - Intro 00:04 - Overview 05:08 - Reverse engineering part 1: overall description 06:07 - part 2: 12V DC-DC converter 09:05 - part 3: voltage monitor circuits 13:14 - part 4: 3.3V and 5.0V DC-DC converters 13:57 - part 5: DC-DC converters shutdown circuits 16:00 - part 6: standby power supply
Errata: Due to an error during reverse engineering the networks Diode-Resistor-Capacitor are actually snubbers connected in parallel to each transformer primary. Nothing is connected to the gate of the MOSFETs.
Notes:
Most parts are US or European parts. It is obvious that Russia don't have the modern technology to design such board with their own parts. Russian parts: * The toroidal transformer * The 10A fuse * Maybe the electrochemical capacitor
Main parts used on this power supply: * UCC28084 (Texas) PWM controller for the 12V power supply * TPS54356 and TPS54357 (Texas) PWM controllers for 3.3V and 5V Power Supplies * MAX974 (Analog Devices) Quad comparators with internal voltage reference * IRF7328 (Infineon) dual P-channel MOSFET * MJD112 (ON Semi) NPN Darlington * FDS4488 (On Semi) N-channel MOSFET * IRFR5305 (Infineon) P-channel MOSFET * SI4156 (Vishay) N-channel MOSFET
Weird things: * The grid of one unused MOSFET is left open * What is the purpose of the fuse ? What will happen to the missile if the fuse blows ?LDM #359: RAF Avro Vulcan Ground Position Indicator - MK.4 - Part 1Le labo de Michel2024-02-26 | This video presents the teardown of a vintage Ground Position Indicator which was used in Avro Vulcan aircrafts. If someone knows something about this device please let me know, particularly the purpose of the various controls on the front panel.
00:00 - Intro 03:54 - Teardown 05:16 - Disc & Ball integrator 07:33 - Mileage computations 13:44 - Normal / Fix modes 15:16 - Synchronous motor 16:14 - Test with manual heading change 17:26 - Mileage simplified electro-mechanical diagram
Notes: - At that time the goal of the third disk and ball integrator (on the bottom side) is unknown Edit 07/03/24: according to @Pulsynetic the disk and ball integrator is used for a cosecant function which permits the correction of the meridians convergency to give the longitude. - On the simplified electro-mechanical diagram the outputs of the disk and ball integrators are not the latitude nor longitude but the E-W and N-S mileages.
Mileages computation:
The mileages are computed using two disc and ball integrators. The disc of each integrator is linked to the same M-type stepper motor. The frequency of the signals which drive the motor must be proportional to the ground speed. The input of the integrator (the displacement of the balls) is an image of the sine and the cosine of the heading. This is simply done using slides and levers linked to the heading shaft. The angle of the output shaft is therefore an image of the integral of V(t)*sin(Theta(t)) and of V(t)*cos(Theta(t)), that is to say respectively the mileage on each axis.
Book Computing mechanisms and Linkages by ANTONÍN SVOBODA (1965) randomwraith.com/documents/Svoboda-ComputingMechanismsLinkages.pdfLDM #358: Marconi BMETS Meteorological Computer Interface UnitLe labo de Michel2024-02-17 | This video shows the teardown of a GEC-Marconi military computer. It is a part of the BMETS system which permits the measurement of meteorological parameters for missile flight optimization.
00:00 - Intro 01:31 - MPU13P board 04:02 - Text strings from EPROM "PRGS 1/2" dump 04:15 - Text strings from one EEPROM X28HC256 04:20 - Second board teardown 05:24 - Third board teardown (UPP20) 07:19 - Front assembly 08:56 - DC-DC converterLDM #357: EPR indicator from A300-600 Airbus SimulatorLe labo de Michel2024-01-24 | This video shows the teardown, the reverse engineering and test of an EPR indicator used in a simulator for an airliner Airbus A300-600.
About EPR: https://skybrary.aero/articles/engine-pressure-ratio-eprLDM #356: Teardown of two Russian missile sensorsLe labo de Michel2023-12-29 | This video shows the teardown of two Russian sensors. The first sensor is not a part of an Iskander missile but of a X-101 missile.
00:00 - Intro 00:25 - Optical sensor from X-101 missile 02:30 - 3-axis Fiber Optic Gyroscope (probably from Tornado MLRS)
Technical documentation in russian: https://ela.kpi.ua/bitstream/123456789/30573/1/Stranskyi_magistr.pdfLDM #355: Javelin Missile guidance computer - Part 2: answers (in French with subtitles)Le labo de Michel2023-12-07 | On this video I try to give some answers to some questions regarding the previous video.
00:00 - Intro 01:14 - My French accent 03:13 - Nice boards 04:03 - Is it legal to post this on YT ? 05:01 - SRAM dump ? 06:24 - Powering-on the boards ? 06:42 - Is it legal to own that thing ? 07:06 - Sensor 07:56 - ITAR 09:16 - Prototype ? 09:48 - Vias 09:59 - Power op-amps and fins control
recorded 2023/12/02LDM #354: Javelin Missile guidance computer - Part 1: teardownLe labo de Michel2023-12-01 | This video shows the teardown of the guidance section of a Javelin missile FGM-148.
Nota 2023/12/24: this video is intended to show the technology now obsolete used in the 80s-90s on military devices. Similar technology can be found in avionics for instance. On that guidance section there is nothing sensitive, it is just a complex CPU board with golden parts.
00:00 - Intro 01:00 - Teardown 02:08 - Input filter 06:08 - FI preamplifier 08:00 - Mixer 10:48 - Servo control feedback potentiometer and reflector voltage setting 13:52 - Motor 15:38 - Frequency setting test 16:34 - Schematic diagram
Technical description:
It uses a 1N26 mixer diode and a 2K48 reflex klystron for the local oscillator. Frequency setting uses a DC motor and several devices linked to the output shaft: * A fixed cam permits to modify the frequency of the reflex klystron. * An adjustable cam permits to change the central frequency of the input filter * A potentiometer permits to change the reflector voltage of the klystron according to the frequency * Another potentiometer is connected to the connector, probably for the servo control of the frequency setting mechanism. * A synchro transmitter * An internal indication of the frequency using coding wheels
Recorded 2023/10/31LDM #352: Sperry Mach/Air Speed indicatorLe labo de Michel2023-11-23 | This video shows the teardown of a Sperry Mach/Indicated Air Speed Indicated ref 2594466-906.
00:00 - Intro 01:53 - Electro-mechanical assembly 04:13 - Electronic assemblyLDM #351:Astek Division Altitude Alert IndicatorLe labo de Michel2023-11-16 | This long video shows the teardown, reverse engineering and test of an Altitude Alert Indicator manufactured by Astek Division in the 70s. The first part of this video shows the teardown followed by the test of this instrument. The second part is more theoretical, the general functioning of this unit is explained as well as some particular topics.
00:00 - Intro 00:40 - Teardown 01:11 - Electro-mechanical assembly 07:22 - Electronic assembly 10:37 - Test 15:52 - Air Data Computer ARINC565 Dual Speed Synchro 18:32 - Altitude Alert - General functionning 24:48 - Synchro, resolver, transolver and differential resolver 33:33 - Coarse window generation 36:48 - Synchro transmitter presence detection 38:30 - Detailed schematic from reverse enginnering
Recorded 2023/10/23LDM #350: TRT Radio Altimeter - Teardown, reverse engineering and testLe labo de Michel2023-11-09 | This video shows the teardown, the reverse engineering and the test of a radio altimeter TRT AHV.5-221 which was used in A300 aircraft.
00:00 - Intro 01:05 - Teardown 06:03 - Non-linear scale 08:21 - Tests 09:34 - ARINC 552 11:00 - Reverse Engineering Part 1: Main circuits 14:11 - Reverse Engineering Part 2: Flag circuits and power supply 15:40 - Reverse Engineering Part 3: Decision Height circuits
Technical details
This Radio Altimeter is compliant with ARINC 552 standard. The servo control loop uses a potentiometer for the feedback and a DC motor for the drive of the tape. The input is a differential DC voltage. The error voltage (feedback voltage - input voltage) is fed to the servo amplifier. The servo amplifier has a special feedback which permits to compensate partially the series resistance of the DC motor. This permits to have a control of the speed of the motor which permits a damping of the control loop.
Connector pinout:
A-B: 26Vac 400Hz L : signal ground Y : signal input (+) Z : signal input (-) a-L : Test push button D-g : 5V lighting e-f : relay contact for decision height (closed when the altitude is below the DH)
Useful links: Burr-Brown document: Control a DC Motor without Tachometer Feedback ti.com/lit/an/sboa043/sboa043.pdfLDM #349: Blackburn Buccaneer height and rate of climb indicatorLe labo de Michel2023-11-05 | This video shows the teardown and test of a Blackburn Buccaneer height and rate of climb indicator KHB0203 manufactured by Smiths.
00:00 - Intro 01:02 - Teardown 05:34 - Test
Technical details: - The vertical speed needle is driven using a synchro receiver - A servo control is used for the altitude. One complete revolution of the synchro corresponds to approximately 25,000 feet. - Not shown on the video: the triangular screw one can see on the bottom of the front panel permits to adjust the zero altitude by rotating the body of the synchro control transformer used for the servo control. - The solenoid used for the flag seems activated by a motorized potentiometer. I didn't test this feature.LDM #348: teardown and test of a Kollsman Servo AltimeterLe labo de Michel2023-10-31 | 00:00 - Intro 02:22 - ARINC 465 Standard 02:40 - Dual speed synchro 03:58 - Teardown 05:33 - Test 07:49 - Flag circuits 08:29 - Flag testLDM #347: DC-10 Clock - Teardown, reverse engineering and testLe labo de Michel2023-10-25 | 00:00 - Intro 00:56 - Teardown 02:34 - Reverse Engineering Part 1: Stepper motor driver 04:39 - Reverse Engineering Part 2: Power supply 05:30 - 60Hz quadrature generator board 06:30 - quadrature generator board test 06:39 - Final design and testLDM #346: HSI Collins 331A-8K - Part 1: Teardown and first testsLe labo de Michel2023-10-20 | This video shows the teardown and partial test of an Horizontal Situation Indicator (HSI) which was used in BAE-146 Aircraft.
00:00 - Intro 01:19 - Teardown 10:08 - TestLDM #345: Cessna dual engine RPM % indicator - Teardown, reverse engineering and testLe labo de Michel2023-10-14 | This video shows the teardown, the reverse engineering, the repair and the test of a vintage Cessna dual turbine RPM indicator.
00:00 - Intro 00:37 - Teardown 03:04 - Preparation for reverse engineering 04:17 - Reverse engineering part 1: power supply 05:33 - Reverse engineering part 2: main circuits 07:20 - Issue #1: wrong transistor orientation 09:15 - Issue #2: cracked solder joint 10:11 - Test
Note about the construction: the electronic side of this indicator was poorly constructed. The dual layer non-plated through hole PCB without solder mask nor conformal coating has resulted in a solder joint crack. Someone attempted to repair this instrument (maybe because of this issue) and one 4-pins Darlington transistor was not fitted correctly during this repair.
Internal circuits: the input signal is fed to a comparator which delivers a square wave signal. This signal is fed to a discrete monostable which delivers a rectangular signal. The duty cycle and therefore the mean value is proportional to the input frequency. After filtering the DC voltage created is used as the input of a servo control loop. The feedback device is a potentiometer. A chopper using two dual emitter pnp chopper transistors converts the DC error voltage into an AC error voltage which is fed to the servo amplifier which drives the AC motor. This instrument incorporates an inverter for each channel for the generation of the AC voltage required by the motor. The use of an AC motor and the choice of a DC power supply voltage complicate dramatically the circuits of this instrument.
Particular parts used:
Dual emitter PNP chopper transistor: Sprague 460070-2 Servo amplifier power stage and inverter: Darlington U2T101
Pinout from reverse engineering:
(x): left engine A (K): input signal (5Vpp min, positive signal), 70Hz for 100% B (F): common line for power supply and input C (E): positive power supply (14 or 28V, automatic selection by the unit)
Recorded 2023/07/23LDM #344: Intertechnique Fuel Quantity Indicator - Teardown, reverse engineering and testLe labo de Michel2023-10-10 | This video shows the teardown, the reverse engineering and the test of a digital fuel quantity indicator manufactured by Intertechnique. fr.wikipedia.org/wiki/Intertechnique
00:00 - Intro 00:55 - teardown 03:36 - Reverse engineering part 1: power supply 04:49 - Reverse engineering part 2: dimmer circuits 06:13 - Reverse engineering part 3: analog board 07:04 - Test
Connector pinout:
A: ground B: negative power supply -20V C: positive power supply +20V D: input voltage (1 to 5V with 5V reference voltage) E: reference voltage input F: ground H: 82 ohms to E J: digital ground (connected to analog ground through two diodes back to back) T-U: lighting (0 to 5Vrms 400Hz)
Technical description:
- The input voltage is fed to a 10-bits ADC made with a 4040 counter, one 10-bits DAC, two comparators and one JK flip-flop. - The 5V power is an SMPS which uses a classic SG1524 configured as a step-down DC-DC converter. - Display value is 0 for 1V input voltage and 5V reference voltage - Display value is 9900 for an input voltage equals to the voltage reference - The rightmost digit is always 0, fuel quantity displayed is XXX0 pounds - This instrument requires two power supply voltages: +20V and -20V. - There is a dimmer circuit which permits to attenuate the display luminosity according to the level of the lighting voltage. - The refresh rate is approximately 2 seconds. - The display is blank if the reference voltage is below 2V - The display is blinking if the lighting voltage is not presentLDM #343: Columbia Servo AccelerometerLe labo de Michel2023-10-04 | 00:00 - Intro 00:35 - Teardown 01:45 - How it works 01:52 - Reverse engineering 03:31 - Repairing the coil 04:03 - Open loop test 04:53 - Closed loop test
Links:
LDM #169: Aircraft Servo Potentiometer Type 6A/4725 Teardown and Tests youtu.be/_i8dZ0o0ZIsLDM #342: Blackburn Buccaneer Gyro Reference UnitLe labo de Michel2023-09-29 | 00:00 - Intro 03:28 - Roll stabilization mecanism 05:35 - Pressure switch 06:52 - Internal assembly 07:50 - Gyro unit 09:39 - Rotorace gyro 11:05 - Gyro 11:30 - Test
LDM #349: Blackburn Buccaneer height and rate of climb indicator (beginning from 2023/11/17) youtu.be/4Fg5cnIGl-ULDM #341: Indicator N2 Tachometer - Teardown, reverse engineering and testLe labo de Michel2023-09-25 | 00:00 - Intro 00:50 - Teardown 04:47 - Torquer test 05:55 - Reverse engineering part 1: frequency to voltage converter 08:27 - Reverse engineering part 2: amplifiers 09:16 - Reverse engineering part 3: servo amplifier 10:05 - Test 12:02 - Charge balance frequency to voltage converter - comment ça marche ? 17:20 - Comparison with actual measurementsLDM #340: C-5 Galaxy EPR Indicator - Teardown and testLe labo de Michel2023-09-21 | 00:00 - Intro 00:30 - Servo amplifiers module 01:53 - Figuring out the pinout 02:57 - Test 04:21 - Opening the instrument 07:15 - What's inside the electro-mechanical assembly
youtu.be/WhxyEzI6IF0 youtu.be/tN16HeZ750c youtu.be/Dlsc9dlFBGILDM #339: Smiths Distance Miles Indicator - Teardown and testLe labo de Michel2023-09-14 | This video shows the teardown and test of a distance miles indicator manufactured by Smiths. At the end a quick reverse engineering is performed for the input connections. This instrument requires an external AC voltage reference voltage for the feedback potentiometer (out of phase regarding input signal). This permits to have a display which doesn't depend on the instrument itself.
00:00 - Intro 01:54 - In search for power supply pins 04:48 - In search for input pin 05:47 - In search for flag pins 06:11 - In search for ground pin 07:34 - Preliminary test (open loop) 08:33 - Final test (closed loop)
Pinout: A-B : Power Supply input 26Vac 400Hz C : input common D(-) E(+) : flag (28Vdc) F-G : feedback potentiometer (2k) H : inputLDM #338: Air Nautical Miles Indicator - Teardown, reverse engineering and testLe labo de Michel2023-09-08 | This video shows the teardown, the detailed schematic diagrams and the test of a vintage Elliott Air Nautical Miles Indicator manufactured in the late 60s. The input is a negative DC voltage. The miles result is shown using a mechanical display activated by a stepper motor. The more negative the input voltage, the faster the counter advances. The input voltage is fed to a VCO. The VCO generates a pulse signal with a frequency proportional to the negative input voltage. This clock signal is fed to the stepper motor driver circuits. This indicator uses several smd DTL logic ICs and two op-amps for the VCO.
00:00 - Intro 00:34 - Teardown 01:37 - Electronic boards 04:11 - Reverse engineering - VCO circuits 05:13 - Reverse engineering - Stepper motor control 06:23 - Test
A: -6.4V reference voltage output B: input voltage (must be negative) C: common for input voltage J-K: 5V for lighting G-H: 26Vac 400Hz power supplyLDM #337: RAF Avro Vulcain Electrical Indicator Type 101 - Part 2: Reverse Engineering and testLe labo de Michel2023-09-05 | This video shows the reverse engineering and test of a vintage RAF Avro Vulcain. The teardown was shown in previous video: youtu.be/cpOrcHsgwJY
00:00 - Reverse Engineering 02:35 - Test 03:41 - Radar frequency estimation
Part 1: LDM #336: RAF Avro Vulcain Electrical Indicator Type 101 - Part 1: teardown youtu.be/cpOrcHsgwJYLDM #336: RAF Avro Vulcain Electrical Indicator Type 101 - Part 1: teardownLe labo de Michel2023-08-30 | This video shows the teardown of a vintage RAF Avro Vulcain Electrical Indicator Type 101 used for the Doppler radar system. It contains an air speed indicator, a drift indicator, a distance miles indicator, and a ground speed indicator using a bar graph. This indicator uses plenty of sub-miniature and ultra-miniature vacuum tubes.
00:00 - Intro 01:20 - Teardown 03:21 - First power up 04:36 - Filters box 05:31 - Indicators 08:05 - Indicator repair
Part 2 (on line 2023/09/05): LDM #337: RAF Avro Vulcain Electrical Indicator Type 101 - Part 2: Reverse Engineering and test youtu.be/TJI_owLNPZg
recorded 2023/08/04LDM #335: Turbine Gas Temperature Indicator - Teardown, repair and testLe labo de Michel2023-08-25 | 00:00 - Intro 01:20 - Teardown 01:50 - Desoldered capacitor 03:52 - First test 05:15 - Repair 06:30 - Quick test with a solder iron 07:06 - Final test using a thermocouple simulator
This video shows the teardown, the repair and test of a Turbine Gas Temperature Indicator manufactured in 1986 by Intercontinental Dynamics. The power supply and the needle command circuits are identical to the ones of the RPM indicator described in video #97: youtu.be/aOXe8n5juoM
The input is a K thermocouple. Cold junction is present on the front-end board using 2 massive copper pieces. The voltage is amplified using two op-amps OP41 and converted into a digital data using a Teledyne 3-1/2 digit ADC TSC8750 with BCD outputs. This digital data is displayed on three 7-segments displays using three classic BCD to 7-segments drivers CD4511. This digital value is also fed to the addresses of two EPROMs. The EPROMs contains sine and cosine tables which drive two 8-bits DACs DAC0800. Each DAC output is fed to a power op-amp LH0021K which drive a sine-cosine DC synchro which sets the needle.
Pin-out of the rear connector: G: 0V F: 26VAC 400 Hz E-D: lighting A-C: K thermocouple input
Recorded 2023/07/29LDM #334: Static Inverter PS285: reverse engineering and modification for 3-phases inverter.Le labo de Michel2023-08-17 | This video shows the reverse engineering of the PS285 inverter. After understanding how this inverter works I show a simple method to synchronize the output signal to another inverter. Finally the video shows the new inverter which delivers two AC signals at 400Hz with 0 or 120° phase shift using two PS285 inverters.
00:00 - Intro 00:47 - Reverse Engineering Part 1: 400Hz sine oscillator 03:11 - Reverse Engineering Part 2: Output stage 04:02 - Reverse Engineering Part 3: Output voltage control circuits 05:16 - Modification for slave mode operation 06:08 - Slave Mode Test 07:38 - Modification for slave mode 08:28 - Phase shifter and final design 09:49 - Test
Link to part 1: LDM #323: Aircraft Static Inverter EMP Electronics PS285: teardown and test youtu.be/2xIdZvDX5XALDM #333: teardown and test of a Smiths Radio Magnetic IndicatorLe labo de Michel2023-08-12 | This video shows the teardown and test of a Radio Magnetic Indicator (RMI) ref WL/107 manufactured by Smiths.
00:00 - Intro 00:41 - Teardown 01:49 - Searching for the pinout 03:22 - TestLDM #332: Static Air Temperature Indicator KOLLSMAN INSTRUMENTSLe labo de Michel2023-08-06 | This video shows the teardown, the reverse engineering and the test of a Static Air Temperature Indicator Type C 25725 10 001 manufactured by Kollsman Instruments in 1980. This indicator uses a magnetic amplifier with two transistors for the servo control of the needle.