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Feature request - rebreather solenoid signal

Discussion in 'Shearwater Research' started by doctormike, Jul 8, 2019.

  1. doctormike

    doctormike ScubaBoard Supporter Staff Member ScubaBoard Supporter

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    I dive a JJ CCR, DiveCAN version. One thing that is helpful in monitoring an eCCR during a dive is hearing the solenoid firing. Between a heavy hood for cold water diving and my own high frequency hearing loss, I can almost never hear mine.

    Would it be possible to do a firmware upgrade to put something simple on the controller and/or NERD display that would indicate when the solenoid is firing? Maybe just a small red dot in the corner of the screen, that could be shut off by people who didn't want it?
     
    Caveeagle and _Ralph like this.
  2. AJ

    AJ Solo Diver

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    Just showing a small dot is'nt a real issue I guess.Imo he real problem is making sure the solenoid is really firing. This means more hardware to monitor the solenoid (if it even exists?). Just showing the signal from the computer could give a false sense of safety I think?
     
    kelemvor likes this.
  3. doctormike

    doctormike ScubaBoard Supporter Staff Member ScubaBoard Supporter

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    No more so that the audible sound of the solenoid firing is a false sense of safety - it's just one more thing to keep you in tune with the rhythm of the unit.

    I mean, your controller knows when the solenoid is getting a signal to fire, I just would like to know that too. Sure, it's possible for the solenoid to be fired by the head but no O2 to be delivered because it is failing closed or because you are out of O2, etc.... But I'm not saying that listening for the solenoid takes the place of watching your PO2.

    This would be purely a firmware issue, not asking for any sort of solenoid monitor.
     
  4. rjack321

    rjack321 Captain

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    If your ppO2 is stable then your solenoid is firing or your orifice is leaking as intended.
    Doubting yourself? Do a dil flush and watch it drop and come back up. IMHO the red dot is a half-arsed "check" that is not actually verifying O2 delivery.
     
  5. doctormike

    doctormike ScubaBoard Supporter Staff Member ScubaBoard Supporter

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    So all that stuff about listening for your solenoid is wrong? I mean, maybe it is, but I hear so many experienced divers talking about that I thought it might be helpful.
     
    Caveeagle likes this.
  6. The Chairman

    The Chairman Chairman of the Board

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    I like it, but make it a green light for O2.
     
    Caveeagle likes this.
  7. Caveeagle

    Caveeagle Rebreather Pilot

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    I also have a hard time hearing the click. While we are wishing.. maybe a green hour glass that refills every time the solonoid fires.

    One problem I see is whether the indicator would just show the trigger voltage, or would it actually confirm a completed circuit and truly validate the solonoid did fire.
     
    rjack321 likes this.
  8. jgttrey

    jgttrey ScubaBoard Supporter ScubaBoard Supporter

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    Meg Apecs 4 handsets have a green asterisk that appears when the firing signal is sent to the solenoid. I don't pay attn to it, but I can hear the click and hear the gas being injected. Even without leaky valve, injections are not that frequent at depth, so you'd have to just sit there at watch it for a while to catch it in the act. I'm not sure it'd be very practical.
     
    rjack321 likes this.
  9. rjack321

    rjack321 Captain

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    The click you can in theory hear passively. And its the actual solenoid opening so that'd a pretty good hint that O2 is flowing. I can barely hear mine, it has to be super quiet with no boats, bubbles on a cave roof, or OC divers around. So honestly I don't even try to track it, there are other more reliable indicators things are working.

    The Apecs electronics on the Meg do have a solenoid firing symbol, but I have never sat there looking at the handset to actual watch it. If you really really wanted a "solenoid firing" light it would be better as part of a HUD than on your wrist IMO. But then you run the risk of having conflicting information and another layer of mental diagnostics to sleuth out the "ppO2 is dropping but my light is firing" situation - assuming you don't just trust that the solenoid will catch up which would be the biggest issue IMO.
     
  10. hroark2112

    hroark2112 Tech Instructor

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    My .02

    If your PO2 isn't dropping, you're somehow getting oxygen. A little blinky would just tell you when it was firing, your PO2 rising would tell you that you're really getting oxygen.

    I'm not sure why one would need the extra blinky.
     
    rjack321 likes this.

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