No one in this discussion has advocated applying power without a switch. I think we all understand that. The discussion is what types of switches should be allowed.
Tony
Revision to Tripoli Rule Regarding Wireless Remote Switches
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Tony
Evolvant
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I have to admit I've been following this thread very closely and am extremely confused. What started as a "no wifi switch" conversation has taken all sorts of directions.
Based on what I've ready, which is every post, using the "switch" connection on a altimeter with a mechanical switch isn't even enough. "All" altimeter designs must now have a mechanical break/switch between the power and altimeter or charge and altimeter. Is that true @Steve Shannon? Or is this only the case when using approved wifi/magnetic switches?
Cheers,
Paul
Based on what I've ready, which is every post, using the "switch" connection on a altimeter with a mechanical switch isn't even enough. "All" altimeter designs must now have a mechanical break/switch between the power and altimeter or charge and altimeter. Is that true @Steve Shannon? Or is this only the case when using approved wifi/magnetic switches?
Cheers,
Paul
Speaknoevil
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Hi Paul,
Here’s the condensed version of our week old new rule:
Before you are on the range or at a preparation area where other people could be injured, there must be some kind of physical break that will absolutely prevent the charges from being ignited.
That can be a mechanical switch in the lead coming from the battery, a mechanical switch connected to the switch terminals if you’re sure it truly kills power to the altimeter, or mechanical switches going to the individual charges. As much as I personally dislike twist and tape, it’s allowed as a form of mechanical switch for those who swear by it.
The reason wireless remote switches got involved is that for all other switches the the rocket must be on the pad and pointed up before the mechanical switches can be turned on. For the wireless remote switches the mechanical switches can be turned on before putting the rocket on the pad if the wireless remote switch is open, then the wireless remote switch is turned on after raising the rocket. That eliminates having to have your face or body next to the rocket or being up on a ladder when power is actually delivered to the altimeter.
Evolvant
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Thanks, Steve. And thank you for all you do. Looking forward to meeting you in person at LRDS.
My question is regarding the use of mechanical switches if you can be absolutely sure power is disconnected to altimeter case.
"Most" of us wouldn't know how to determine this. If we wire a mechanical switch to the switch terminals on a altimeter we expect the designer to manage this. "Most" of us have no way of reverse engineering this to "absolutely be sure".
I think that puts Tripoli in the switch certification business to figure out what altimeter(s) "absolutely do this". Is that really what you want?
Thanks,
Paul
My question is regarding the use of mechanical switches if you can be absolutely sure power is disconnected to altimeter case.
"Most" of us wouldn't know how to determine this. If we wire a mechanical switch to the switch terminals on a altimeter we expect the designer to manage this. "Most" of us have no way of reverse engineering this to "absolutely be sure".
I think that puts Tripoli in the switch certification business to figure out what altimeter(s) "absolutely do this". Is that really what you want?
Thanks,
Paul
I have a question about the wifi switch exception. The new TRA rule states that if you use an approved wireless switch you can connect power to the altimeter when you are on the pad as long as the rocket is pointed in a safe direction. You are not required to be on the rail with the rocket pointed up (aka the launching position). Correct?
But NFPA requires...
"The function of firing circuits and onboard energetics shall be inhibited until the high power rocket is in the launching position."
If wireless switches don't meet the standard for inhibition then how can the exception exist in the new TRA rule? Maybe it's a technicality but I want to make sure I understand.
But NFPA requires...
"The function of firing circuits and onboard energetics shall be inhibited until the high power rocket is in the launching position."
If wireless switches don't meet the standard for inhibition then how can the exception exist in the new TRA rule? Maybe it's a technicality but I want to make sure I understand.
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If you’re not sure, you have two choices:
A. See what the manufacturer says in their instructions, or in response to you asking, or
B. Put the mechanical break in the power line.
Your understanding is correct. When we originally approved the Eggtimer WiFi switch we felt that it was safe enough to work as an inhibit once a person was on the range. It’s definitely better than climbing onto a ladder and trying to activate a switch while several feet in the air and there’s at least one tv show that illustrates the risk of that. I still feel that way; a wireless remote switch still offers that as a safety advantage: You remove the last inhibit from a safe distance.
But as others pointed out to us that’s possibly not inhibited enough when surrounded by other people who may not be paying attention to you. The document describing inhibits that the air force uses requires two independent inhibits when the chance of injuries is higher and three independent inhibits when there’s a good chance of a fatality if the energetics blow or a rocket motor ignites.
So, another way to think about this is when you’re behind the flight line you have to have two inhibits. A mechanical switch or a dead circuit leading to the wireless remote switch is one of them and the wireless remote switch is the second. Once you’re ahead of the flight line you can remove the mechanical inhibit.
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Then why not require two inhibits, one of which must be physical and one of which must be remote? (Playing devil's advocate here... not trying to drum up WiFi Switch sales...)
rharshberger
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since this rule is effective immediately , how are people to be informed?
rso needs to know what to check for
not all altimeters beep or have flashing lights
it would be a pain to go to a launch and not be able to launch your rocket that has been compliant in the past since you did not know the new rule
it does seem like we need to ban shurter switches ( a failure waiting to happen)
a list of certified products or banned products needs to be posted
keep in mind there are those who don't check FB or this forum or the TRA forum or the TRA report
rso needs to know what to check for
not all altimeters beep or have flashing lights
it would be a pain to go to a launch and not be able to launch your rocket that has been compliant in the past since you did not know the new rule
it does seem like we need to ban shurter switches ( a failure waiting to happen)
a list of certified products or banned products needs to be posted
keep in mind there are those who don't check FB or this forum or the TRA forum or the TRA report
I for one hear what you are saying. And unfortunately this can of worms has been opened and is what it is. There is an old rule of life saying that, "ignorance of the law (rule) is not a defense when you say "but I didn't know". Much much much has been published and stated about this. Not being informed is not the responsibility of the TRA but rather that falls on the flyer. Some may become disenchanted and quit but then that could be the fall out. If you know someone who is a flyer who isn't paying attention then might I suggest you let them know of the revised rules.
hopefully the approved certified parts are posted along with the banned ones to several places and the to prefect list
I am the only one that I know of keeping my club informed
so I guess it is out of thr question to have a separate wifi switch to turn on the power to a quantum?
I am the only one that I know of keeping my club informed
so I guess it is out of thr question to have a separate wifi switch to turn on the power to a quantum?
A few years ago we subscribed our TAPs and Prefects to the TAP and Prefect forums on the Tripoli website. I posted the announcement there also so all TAPs and Prefects should have received an email with the announcement.
Of my announcements this one has been shared the most times.
Based on the email and calls I’ve received many people have received the information.
However, rather than making it the job of the RSO table to check, this announcement is to inform the flyers. They are the ones who need to make sure rockets are powered down when taken to the RSO table.
I bow to the discussion police...Piece brother...
Speaknoevil
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This is perpetuation of an incorrect conclusion that was fueled by the outcry of a handful of individuals, more than half of which I'd venture to guess were using Chinese knockoffs of the real (Swiss-designed) Schurter switches. The electrical specs and performance of real Schurter switches are in no way "a failure waiting to happen."
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There in lies the problem, cheap junk switches. That also goes for some of the slide switches I have seen used.
Speaknoevil
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Absolutely Fred! What they say in the software world, "garbage in, garbage out," applies to hardware also.
https://www.farnell.com/datasheets/2343551.pdf
Lifetime 300 operating cycles (without load)
I have seen them fail after 10 to 20
genuine shurter, I rest my case
Lifetime 300 operating cycles (without load)
I have seen them fail after 10 to 20
genuine shurter, I rest my case
Speaknoevil
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Yep, linked the same data sheet in post #524 of this thread.
If you bought shurter switches, you bought a knockoff. The name is Schurter.
(Just kidding you...)BTW, load in this case is high voltage, 110 to 220VAC that is often connecting motors and could be inductive, cause arcing. Our milliamps at 3.7V to 8.4VDC is not really measurable as a use case.
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rharshberger
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Charles_McG
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I thought in the software world that GIGO was the optimistic case.
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I'm preaching to the choir, here, but in my opinion, **how** builders and flyers connect and use these devices will always be a much greater issue than **which** device they use. If the inside and bulkheads of av-bays were inspected by a qualified RSO (and no, I'm not suggesting that), very many of them would not be allowed to fly. There are plenty of component choices - cheap to expensive, slick to simple. If you don't take care with the electronics assembly, the failure rate will be high. Don't just get lucky.
Had to get that off my chest. Thanks.
Had to get that off my chest. Thanks.
Yep, posted the same data sheet in post #524 of this thread.
If you bought shurter switches, you bought a knockoff. The name is Schurter.
BTW, load in this case is high voltage, 110 to 220VAC that is often driving motors and could be inductive, cause arcing. Our milliamps at 3.7V to 8.4VDC is not really measurable as a use case.
I posted the pdf, I can lead you to specs, I can't guarantee that you read them
no load means no load LOL, if you test the switch several times you have decreased the life of it
I could be wrong, but I agree. On our field, I have never seen a failure with one of these switches. I personally stopped using them in favor of twist and tuck. My only failure was due to a broken solder and I can’t blame that on the switch.
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