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My rocketry team and I are currently designing the system architecture for the electrical component of our rocket test stand for a static fire test. We have not started implementing this and I would like to have any feedback on this current system, are there flaws to this design, should we change anything? Any feedback would be appreciated.

enter image description here

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  • $\begingroup$ Some light color coding would be nice for the readability of the diagram $\endgroup$ – CourageousPotato Sep 10 at 3:37
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I'll take a whack at it - like CourageousPotato said color code your power/data lines for easier differentiation, and I personally would like to see ground indicators (but may not be necessary). I think breaking out the sensors into a dashed assembly and saying what sensors would be useful. Why do you have a primary and redundant battery for each of your lines? Do you really need a redundant battery to power your beaglebone or DAQ? All of your other assembles are zero fault tolerant.

I also imagine most of your interfaces are a little more complicated than what you indicate. The sensors are I2C or SPI, which will have data rx/tx, clock l and vio. Identifying the Ethernet or USB as a serial or uart as well, maybe?

I found an example of some college stuff I did. Not saying this is what it should look like, but just to give you something to compare to. This is a fairly high-level first take at the electrical interconnectsenter image description here

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The power supply can be simplified - the data processing / control module is currently supplied by 7.4v at 7.4 amps. Instead of dedicated batteries I'd consider connecting your larger 14v batteries to + and - DC bus bars and having that power the whole system.

The control module's power can then come from a 2:1 step down DC transformer connected to that bus. The CM only draws 56 watts now but size it up to 75 or 100 watts and you have room for growth. If you want to make extra sure that much current doesn't go to the control module you can (should) put a more sensitive circuit breaker between the transformer and the CM.

Input and Output modules can be powered from direct connections to the DC bus.

As for circuit protection: ideally fast-acting circuit breakers before all 3 of those legs. And for safety's sake, shielded data cables with the shields terminated at the DC bus side, not the electronics side. Whatever electrical noise you have, you don't want it in your low-voltage fire control circuitry. That's how you get misfires. An EMI shielded enclosure is also important for that reason.

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