In part of my learning the ins and outs of how FG really works, I found another space I can contribute - the electrical system.
The current system has no way of handling circuit breakers or measuring a load across a whole bus.
The system now expresses a bus like this:
<bus> <name>...</name> <prop>/systems/electrical/outputs/device</prop> <prop>/systems/electrical/outputs/device2</prop> . . . </bus>
What I propose is something like this:
<bus> <name>...</name> <circuit> <name>...</name> <capacity>capacity_in_amps</capacity> <prop>/systems/electrical/outputs/device</prop> <prop>/systems/electrical/outputs/device2</prop> . . . </circuit> </bus>
At this point, the bus can be organized into multiple breaker protected circuits on a single bus. The only part of missing data is the Ampere draw of each device.
This could be done within the electrical system definition like this:
<prop>/systems/electrical/outputs/device load=n.n</prop>
This would be the "easy" way to supply the data. However, I think it might be better if the power draw figure was part of the instrument definition itself. This would require 2 new tags added to the xml files that are used to define each instrument - I'm referring to the configurationd data found in data/Aircraft/Instruments.
This sounds like a good idea, but I expect that the lack of good information spoiled the idea. One might be able to get the power consumption by a device, but often the peak power consumption is much higher. And it's the peak power consumption that causes circuit breakers to pop out.
I could imagine that certain actions can cause circuit breakers to pop most of the time on some aircraft, but defining the power consumption based on specific actions might be a little to much to ask for aircraft developers.
The first tag would be <device-class>. This would be something like "nav-radio" or "avionics-fan". It would be used by the load calculator to locate the load value associated with a particular device.
The second tag would be <load> or <power-draw> or something similar. It would be a double value containing the total draw for the device. When the load calculator comes by, this is the number that gets added to the total (obviously).
The idea is to allow custom devices to hold their own power draw values independant of the "wiring". For instance, you could change out the "stock" nav radio for some fancy unit that combines more than one function but has a higher power draw. The device would still be of the class "nav-radio" but would contain an updated power draw figure. The change would only occur within the instrument panel file and would make sure that no matter the unit installed, the power draw value would follow the device and not the "wiring harness".
The circuit load would be calculated each time the electrical system's update method is called. If the total load exceeds the circuit capacity for longer than 2 seconds, the breaker would "pop" and power for that circuit would be cut off.
If this is something that you think should be implemented, let me know and I'll start working on the code for it.
Erik
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