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This is how it all came together

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  • This is how it all came together

    I have found that a 7psi switch is a commonly used switch for fuel pressure lights and NO2 indicators in hot we go with 7psi-it should still work -just a little higher waterline. I was trying to work out the electrical flow and ran into a brick wall because the pump is a reversible gear pump and how do I work with the reversing polarity-I wasn't going to use two pressure switches for the FWD tank and two for the AFT tank. I realized that I could do it with a common blocking diode. This allowed the power to flow thru it when emptying the tank but blocked and shunted the positive thru the pressure switch for the fill mode. When the tank is to the full point and having compressed the air to 7psi, the fill power is shut off. Using the diode allows the empty mode(reverse polarity) to still be available even if the tank pressure is still at or above the 7psi mark. If I had used the pressure switch to just shut off the pump, the ballast tank would not be able to be emptied at that point. Also note the solenoid valve to prevent the tank from just emptying itself by bypassing the gear pump due to the pressurized tank-it only activates when positive is applied in the correct polarity to the pump to empty the tank-and when in the static or fill mode it sees a ground at both it just stays closed due to the separate ground and not the reversed ground from the motor.
    Last edited by Bob Gato; 11-05-2019, 04:33 PM.

  • #2
    Cleaned it up so we could see it. Hope you do not mind.
    Tom Click image for larger version

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    If you can cut, drill, saw, hit things and swear a lot, you're well on the way to building a working model sub.


    • #3
      Thanks for the assist, Tom- I was literally in a restaurant when I scribbled that one on the back of a paper place mat explaining it to someone. Before we left , I took a Quick picture
      Last edited by Bob Gato; 11-06-2019, 09:40 PM.


      • #4
        Shout out to the Quartermaster, for noticing that my stated rank (Ensign) does not match my shoulder boards...
        Last edited by Bob Gato; 11-11-2019, 09:31 PM.