The overhead panel and the pmSystems software are the nerve center of the aircraft systems. Most of the aircraft systems are controlled and monitored from the FWD and AFT overhead panels. Building and wiring the overhead is one of the most complex tasks with building a flight deck. The necessary effort was completely underestimated by me at first. At the end it took me 6 month part-time to build and to finalize the overhead, and to put it into operation. However, it was worth to do it and it is the part of the flight simulator I most proud of it.
This was the easiest part of the overhead project. In 2007 I bought the FWD OH frame, the panels, and all the electrical stuff, like switches, annunciator, rotary and switches, most from Cockpitsonic, Germany. I got all the stuff in one big plastic bag and was busy for the next 2 weeks. However, it worked well and the next step was to make the wiring and interfacing of all the annunciators and controls.
Full functional B737 FWD overhead, the nerve center of the aircraft systems
I do not have an AFT overhead for the time being. This is not really a big drawback for the aircraft simulation, but of course it would be nice to have on the future. This would require a completely new support frame for the FWD and the AFT overhead.
The back side of the overhead. At the time the image was taken the solenoids where not assembled..
For some stronger signals, e.g. the starter solenoids and LED backlit, I use 3 units of the 'Relaiskarte' 190363 - 62 from Conrad Electronic. The input circuit needs only 5mA input current to switch a 12V relay.
Click the item to expand the schematic
As in other parts of my flight deck I decided to use the Opencockpit cards for interfacing the signals, from the overhead to the system and vice versa, too.
The following OC boards are used for the FWD overhead:
- 1x USB Expansion card
- 3x Master card
- 2x USB Servomotors card
- 2x Displays card
Overview Interface boards of the FWD Overhead. A small passive USB hub inside the OH provides the necessary USB ports for the three USB cards.
Conrad Elektronik: http://www.conrad.de/ce/de/product/190363/RELAISKARTE-BAUSATZ
Opencockpit Shop: http://www.opencockpits.com/catalog/gauges-c-48.html