I have some 3mm nylon screws, and some 4-40 steel screws to mount with.. but both of them have a problem with one of the two narrow mounting holes. The screws clip the WiFi board. How should I go about mounting this? Perhaps some silicon tubing as a conformal washer, used with a longer screw? How do you mount your quantum?
Juicy is good... it's big and won't fry easily.
The typical deployment output circtuitry has one of the two legs connected to a common (ususally +V if you're using FETs, but we use BJT's so it's GND) and the other leg switched on/off by your deployment transistor, by the processor. The reason that NAR/TRA requires a disconnect on the deployment power is that you only have one thing - the transistor - between your battery and the igniter. If the transistor should fail (i.e. a fried-shorted FET) or you have some kind of glitch in your circuitry then your igniter is going to fire the instant that you provide power to it.
The Quantum basically includes a switch for the deployment power (an 8A/60W FET) that doesn't come on until near-apogee in flight, in addition to the standard BJT on the "+" side of the igniter. There is no direct connection between the igniters and the deployment power. For continuity testing purposes there is a 4.7K resistor on either side of the igniter to +V and GND, it lights up the optoisolator but the current through the igniter is going to be well under 1mA. For the igniter to fire, BOTH the FET and the BJT have to be turned on. They're controlled by separate outputs on the processor, and by separate events in the software. It would be virtually impossible for these to happen outside a real flight (or a user-initiated test). I was thinking primarily of airstart safety when I put this in, but I believe it also satisfies the NAR/TRA requirements for a L3 deployment power disconnect. Opposing opinions are encouraged and welcomed, of course...
I use 4-40 nylon screws on my Quantum to avoid the metal screw contacting parts on the board. You can also try 3/16 x 1/16 x 1/16 rubber o-rings on the 4-40 metal screws. Slide them on and use instead of a washer. If you also put an o-ring on bottom side of board it holds screw in place. I found these small o-rings at Home Depot.
Now that the Quantum has been out and flown for a while, has its switched deployment power been accepted to satisfy NAR/TRA requirements for L3 deployment?
2.4 The capability must exist to externally disarm
all pyrotechnic devices on-board the rocket.
In this context, disarm means the ability to phys
ically break the connection between a
pyrotechnic system and its power source.
2.4 The capability must exist to externally disarm
all pyrotechnic devices on-board the rocket.
In this context, ‘disarm’ means the ability to phys
ically break the connection between a
pyrotechnic system and its power source.
That could be as simple as running the negative lead off the battery & ground wire of the quantum or wifi switch out the vent hole for a single twist & tape connection
Sad , but meets the requirement
Kenny
There IS an Eggfinder in there too... more details on that one in about a month or so. :wink:
Yup. The Quantum fits just fine, if you leave out the terminal blocks. There IS an Eggfinder in there too... more details on that one in about a month or so. :wink:
Oh yeah, that one was on an Estes Mongoose, AT D21 to AT D10. It only had one Quantum... one channel for the airstart (the booster was blast-separated, that worked just fine) and the second for the parachute at apogee. THAT one blew up the tube... I guess the parachute and wadding was a bit tight in the BT50 tube. The actual flight was just fine, although that D10 took about two seconds to light, it was the recovery that was a little sketchy.
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