I'm a bit hesitant to open this one. People tend to want to validate their own choices.
There’s a lot of different electrical architecture philosophies as everyone knows. For Electrically Dependent aircraft, the design approach broadens even more so.
Nuckolls = (Deviations of) Parallel Direct wire to Battery bus(es) for Electronic Ignitions. Nothing with a coil between bus and critical components (attachment 1). This was a change as earlier approaches had diode bridges and cross-feeds most anywhere in the system.
CF and others = Isolatablity (if such a word) of major electrical components for safety and troubleshooting. Failure of any one component/branch should not require pilot action to continue safe flight etc. (attachment 2)
EFII = Diode bridge cross feed and parallel relay/switch, etc. Also an ECU test function for pre-flight check of ECU. I’m not considering nor debating their bus manager.(attachments 3 & 4) though I may add a version of their automatic (but isolatable) fuel pump activation on falling downstream manifold pressure. Not sure this would bring that much benefit (see swtich placement philosophy, next paragraph.
Please feel free to shoot holes in the preliminary philosophy in attachment 5. My though was to try and gather the aforementioned approaches, save some panel space and weight, create a no-thought/automatic pilot action (all related engine switches “up”) should the situation arise. The Nuckolls Z-28 parallel path simplicity is upset by the coil and injector power singularity; hence the diode bridge. At that point, why not size it for teh full critical load?
Trying to capture the parts I like from the various experts but I gotta draw the line somewhere. I know there’s no perfect solution/have to get to manageable/acceptable risk level, etc. Am I off or not seeing a SPF. I need to know this part of my approach so I can get my firewall and related components laid out. Thanks.
There’s a lot of different electrical architecture philosophies as everyone knows. For Electrically Dependent aircraft, the design approach broadens even more so.
Nuckolls = (Deviations of) Parallel Direct wire to Battery bus(es) for Electronic Ignitions. Nothing with a coil between bus and critical components (attachment 1). This was a change as earlier approaches had diode bridges and cross-feeds most anywhere in the system.
CF and others = Isolatablity (if such a word) of major electrical components for safety and troubleshooting. Failure of any one component/branch should not require pilot action to continue safe flight etc. (attachment 2)
EFII = Diode bridge cross feed and parallel relay/switch, etc. Also an ECU test function for pre-flight check of ECU. I’m not considering nor debating their bus manager.(attachments 3 & 4) though I may add a version of their automatic (but isolatable) fuel pump activation on falling downstream manifold pressure. Not sure this would bring that much benefit (see swtich placement philosophy, next paragraph.
Please feel free to shoot holes in the preliminary philosophy in attachment 5. My though was to try and gather the aforementioned approaches, save some panel space and weight, create a no-thought/automatic pilot action (all related engine switches “up”) should the situation arise. The Nuckolls Z-28 parallel path simplicity is upset by the coil and injector power singularity; hence the diode bridge. At that point, why not size it for teh full critical load?
Trying to capture the parts I like from the various experts but I gotta draw the line somewhere. I know there’s no perfect solution/have to get to manageable/acceptable risk level, etc. Am I off or not seeing a SPF. I need to know this part of my approach so I can get my firewall and related components laid out. Thanks.
Attachments
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