Hey! This is another Flight Deck solution that is intended to use real avionics hardware to create a real flight simulator, in this case a Boeing 737-300.
Hey! This time I desired to investigate an analog ADI unit used in a former 737. (See the video at the end !!)
The Unit...
Brand: Collins
PN: 787-6892-003
The device is a mixture of digital and analog electronics, so tat means that expects synchro transmitters signals and simple analog signals.
The insights....
Here we can see an overview of the mechanics parts:
This is the electronics section that is composed by 5 controller boards and 2 power supply boards attached in the back cover.
Mechanics from the top:
A closeup of the flight directo gears:
Some more pictures:
The test bench...
For this first test related with the Gyro inputs, I'm just powering up the unit with 26Vac 400Hz and connecting two synchros to emulate the Pitch and Roll signals.
I just got the second RDDMI as flown in a Boeing 767.
The reason why I'm using this specific instrument is because this uses Arinc 429 communication, which makes everything much easier when we need to talk with a computer.
The following picture shows the unit and can be found in the market as follows:
Brand: Collins
Type: RDMI-743
PN: 622-5001-107 or 622-5001-109
Good documentation can be found posted by another known person in this business that is building an amazing 767 simulator... please check the following link: Boeing 767 Sim and you will be amazed!!!
Some insights...
After powered it up and execute the BITE test I realized that the Left VOR/ADF pointer was not moving, so I had to disassemble it.
The unit housing is made of 4 independent parts. It got a mechanics compartment, a sliding cover for detach the power supply, a back cover that holds the main connector and the electronics board holder.
Lets see the pictures:
Back part:
So... to open it, first we remove the back part:
The back cover has the main 400Hz transformer as we can see here:
After the sliding cover taken out you will see something like this:
The sliding cover has attached the power supply:
Separating the motor and display drivers from the main system:
Finally we have access to the DC motors that drives the pointers.
Every part in this unit is modular, which makes very easy to access the different parts and repare them.
A closer look of the three DC motors modules:
Three screws need to be removed to be able to take apart one of this modules.
This is the DC motos module for the Right VOR/ADF pointer:
Due the encoder is attached to the reduction gear, special care should be taken to keep the shaft of the pointer in the same position that you toke it out:
Otherwise the pointer is not going to be at the proper position any longer.
Detaching the motor from the reduction gear:
It turned out that the shaft of the motor was a little bit jammed, probably because this unit was sitting in a warehouse for so long. The fact is that after gave it a turn, the motor was running very smooth again!! Problem solved!
Last thing to do is to clean everything before closing...
