The wet replaceable filter is in case of a water landing or in case of heavy humidity, you’ll want to replace it. Any moisture can cause a difference of atmospheric pressure on the sensor.
Difference in pressure, but also that filter will not dry that easily. Leftover moisture in it could also cause mold issues in long term - clogging up the filter permanently.
Skydiving gear is constantly maintained, and the filter would be replaced on a schedule or after any questionable jump, by any responsible jumper; their life is on the line.
I once have been to a factory tour for pressure sensor packaging. The gel inside the sensor is most likely a protective layer for the die and bond-wires as the package / sensor requires "direct" contact to the environment.
The summer I turned 16 (1970) my older brother had joined a local jump club made up of mostly active military personnel. Anyway, I decided I wanted to try jumping too so the old man signed the release form (probably thinking if anything happened one less mouth to feed, lol). Anyway, after the first five mandatory static line jumps the day came for my first free fall. They had an aluminum gadget charged with a co2 cartridge and a pin one would pull when we got over a certain altitude. Well, like an idiot, after I got the parachute strapped on (a Korean War surplus military parachute, a double L, by the way) I accidentally pulled that damm pin. I hollered to the jump master and she said back up against the refueling shed. This I did and a second later that thing went off and my rip cord went flying into the air. But since I had my back pressed against the shed they were able to restring the rip cord and not have to repack the parachute. Anyway, the plane we used had the side door removed. They told me if that thing went off again they would toss me out of the plane, no matter what the altitude. For the record I scared the ground master because I followed directions and counted out the full 1000, 2000, ... 5000 before pulling the rip cord for a full 5 second delay. From what I'm told, that is rare for first time free fallers.
A few things that you might find interesting about the CYPRES. Correct on its "self-calibration" and sensing. It will, as you stated, sample every 30 seconds. Once it senses a pressure change it will lock itself to its last "unchanged" pressure. It will use this pressure as "ground". So the CYPRES is (by just turning on) effective when the take-off location is close to the jump location. If there are vertical obstacles or the jump area is at a different altitude than the take-off altitude then the CYPRES must be manually adjusted to work properly. Some funny things that happen that most users of this product dont know. It only arms itself once it gets 1,500' above its "activation" altitude which is about 750' (I think)...so in the "old days' of skydiving when 2,000; exits were routine the CYPRES may not have been armed. So it would sense "take-off", lock onto an altitude, then begin sampling every few seconds until it realizes that its falling, then begins to sample continuously until it gets to its starting altitude and pressure remains constant (on the ground). For all "normal" jump operations this is fine. There have been times where user error has confused the CYPRES. One incident in California years ago was a skydiving fatality where a jumper had checked her CYPRES prior to getting to the jump area. There was, apparently, a significant hill between where she started and the DZ. The CYPRES thought it was in an aircraft climbing as the pressure change from driving was similar to an aircraft's initial ascent. She did not reset the CYPRES at the DZ and ended up having a malfunction/accident. The CYPRES did not fire as it set itself to an altitude that was either 1000' below the DZ or several hundred feet above it. Also, the expert model was set to activate when a jumper was between 125ish feet and 850ish feet and reaching a speed of 35m/s or 78mph. So if both of those parameters were met (or more importantly if the pressure readings were +/- equal to those parameters) it would fire. This was developed in the 80s when parachutes were much larger and the rates of descent were much slower. They have developed another model that is for smaller high-performance parachutes where the speeds required to cause activation are much higher and another model for students and tandem parachutes were the activation altitudes are considerably higher. The CYPRES also records data, so when sent back to manufacturer (as is the case for fatalities and some malfunctions) they can pull all the pressure/time data from the unit. They actually withhold much of the data as it is proprietary but they will release the data related to the vertical speed and altitude of activation. CYPRES are also made for pilot parachutes where they will essentially activate on a delay from bailout.
Great video, the chord cutter is a standard quarry daisy chain detonator, they use these in quarries and mines to set off the charges and they are secondary detonators that lie on top of the ground, the detonator cables are threaded through them and when they go off, they cut through the plastic insulator and let's the spark shoot through to the next row of charge detonators.. Common in mining and have been repurposed to parachute line cutters..
Cool, glad you finally got around to it. It's a CYPRES 2. Most moisture concerns come from submersion during water landings e.g. swoop ponds. The devices remain inside a closed parachute container almost all their life and are inspected by a rigger regularly. The U.S. regulations primarily say that if such a device is used it must be used in compliance with the manufacturer's guidelines, they don't really dictate much else although industry organizations like PIA, parachute manufacturers (via approvals) and clubs have acted to maintain quality.
The UI box may be a standard Hitachi / clone LCD, a button and maybe some caps/filtering. All within the extended Faraday cage formed by the two metal cans and the shielding braid. If the red wire in the cable and the red wire soldered to the can are the same red wire, they might not trust the braid to remain connected for 12.5 years of packing parachutes, bumping around and jumping out of airplanes.
User manual says unit is waterproof for 24 hours at 8ft depth. The unit here looks identical to the current model. Possibly differs internally though. Product is designed and made in Germany.
My last jump was in the 1990s. I had a good canopy over my head, and at about 1500 ft the AAD went off and my main canopy folded in front of me! Fortunately, my reserve was open and not involved with my main. I pulled my cutaway cord and landed the reserve with only minor injury to my big toe. I vowed never to jump again until I could buy, test, and maintain my own equipment. The owner of the DZ was angry at ME because I threw away the $50 cord and handle as I'd been trained for when pulling the reserve cord!
Ok, so the handle actually IS expensive? I thought the flight instructor was joking when before my first glider flight he explained how to use the parachute in case we'd have to bail out (an EXTREMELY rare occurrence) and said I should hold on to the handle after pulling it as it's expensive. :)
I've been jumping with various Cypres models for years, it's nice to finally see the inside of one (Thanks Dave). There's a few things I've heard over the years that people might be interested in. This is all from memory so I might have miss remembered some of the details. Depending on the model they have to be serviced every 4 or 5 years. As well as replacing the battery they also perform any updates that are required. These updates can include both software and hardware, so expect the hacked on components were probably added during one of the services and were probably not there when the unit was originally manufactured. This is also the reason for the reenterable potting compound. They do a LOT to eliminate failures. Obviously they test the hell out of it during production and limit the service life to remove the front and end parts of the failure rate bath tub curve. During each service they also retest them and compare the data to that units previous test results. The idea is that even if a unit is currently within spec it may be rejected because a measurement has drifted to much from its previous tests, which might indicate it could go out of spec before the next service is due. I can't remember if it was a Cypres or a competing model, but I remember a case where there was a batch of pressure sensors that were faulty in a fairly subtle way. Because of all the testing that goes on they faulty sensors were detected before the sensor manufacture even found out. There have been fatalities due to units firing when the user did have a good canopy, but the cases I know of weren't actually down to a failure of the Cypres. The way they work is they fire if you're travelling faster than a critical speed when you're below a critical altitude (78mph / 750ft for the expert model I think). The snag is that people started jumping really small canopies and putting them into a high speed dive just before landing. As they pushed the limits further and further some people got to the point where they exceeded the firing thresholds even though they had a good canopy. To address this there's now a "Speed" variant of Cypress that has different firing criteria.
The foam will be there to reduce the exchangeable air volume to ensure the highest speed sampling of external air pressure. If they didn’t take this measure to exclude air by filling the voids then the air exchange through the pressure port orifice would render the pressure measurement too slow and inaccurate.
I’ll just add that I had that exact same model fitted my TSE Teardrop skydiving rig when I used to skydive before the kids arrived. My terminal velocity when falling head-first was around 190 mph. So the Cypres had to keep a fairly accurate sample going to know if and when to deploy my reserve. Unfortunately having a reserve deploy when clocking 190 mph head first usually results in broken neck so Cypres had to be trustworthy not to fire inappropriately.
The filter is typically only replaced at service time or by a certified rigger who can service it (this depends on the manufacture date nowadays, but I think it is typically every 4 years although I'd have to ask my buddy who owns SSK, the USA maintenance house for Cypress units). I keep a Vigil 2 in my rig, so I'm not 100% sure. I think it is usually replaced when the device is submerged in water (i.e. the skydiver biffs it and goes for a swim on a failed swoop over the pond or something of the like).
Dave, is it Possible for you to make video comparisson for different AAD (Vigil/m2)? Im sure there are many past service life and worthless lying around 🤔
The cutter is called , or similar to, a "Holex Cutter". (At least that's the common vernacular in the industry. But that's not what I find when searching the term.), or Pyrotechnic Cable Cutter. It's a very simple device. There is a small amount of gunpowder and a plunger sharpened on one end that's ignited by a simple Tungsten resistance wire. We use them in the Special Effects trade for things like cutting large cables that are holding cars in the air. I've never seen one that small before. I'd love to know where to source some of those tiny cutters! So quiet too. The 1/2 inch and larger ones we use make a loud bang! www.cobham.com/mission-systems/safety-and-survival/pyrotechnic-cable-cutters/pyrotechnic-cable-cutters-datasheet/docview/
Jordan, if you want a small one at a reasonable price, search for 'Archetype Cable Cutter'. These are made for rocketry parachutes and have no electronics as rockets typically already have an altimeter/flight computer. They're intended to be reusable, so you'll need to supply your own BP and an e-match, but sounds like that wouldn't be a problem for you. They're very simple to make if you have access to a lathe.
Hey, Dave, given your background in underwater gear I thought you'd have already encountered this sort of thing, but that pressure sensor looks the same as one that I've seen used in a SCUBA dive computer. The dive computer's electronics are entirely encased in mineral oil (or was until I took it apart). I expect that the sensor in this device can work the same way - the gel is probably flexible enough that pressure changes are still easily detected.
All of my rigs are currently running with a Cypres 2 AAD. Cypres sells cutters and filters as spare parts. Vigil is also another big player in the AAD market.
On the maintenance service sheet you put up near the end of the video, there was an X-ray image of the cutters. At the base there is a commercial electric match, also corroborated by 1.2 ohms on the bridge wire. I think the match itself would be sufficient to cut the poly rope and the X-ray leads me to think that’s it, but it’s impossible to tell if there is a boosting charge without disassembly or datasheet. It certainly would not contain loose gunpowder as stated by other commenters. It could possibly use lead styphenate/azide or some other primary explosive.
That MSP430 has an on die temperature sensor if they needed to measure it. It also has a couple of info flash pages that it can self program pages for storing calibration or parameters.
I've once seen RAM modules (some ancient SD-RAM or so) that had its chips as exposed silicon, and then covered with reenterable potting gel. The whole module was then covered with a thin aluminium sheet that was glued onto the PCB on its edges with some 1 or 2mm thick sticky foam stuff. I removed the aluminium sheet and encountered these chips, it was very weird. Thanks to this I now know how it's called :-)
Typically detonators are capacitive discharge circuits. Detonators are specified by their "all fire current." It's hard to say from that was visible in the video wether it is a CDC or just right up to the battery.
With the expert model. If you're traveling over 96mph through the altitude of 750ft it'll trigger the cutter to cut the loop holding your reserve shut deploying your reserve. The waterproofing is for swooping. If you have a water landing you won't ruin your Cypres. I have 8,000 skydives.
That MSP430 is almost certainly one of the high-reliability versions, TI even sells one as space-rated with radiation hardening. I'm sure it meets all required qualifications. The datasheet disclaimers are mostly legalese to cover their butts when someone uses the wrong part for the wrong application.
I would think that the boards outside of the can are to do with protecting the pyro Technic device from RF and other induced current in order to prevent accidental discharge.
In 'Murica, we're a bit government-phobic and generally leave regulation up to trade organizations wherever possible. There IS a fair amount of government oversight over those organizations (FTC, FAA, CPB, etc), but policy is going to come out of the trade group.
It's possible that some of these strange design aspects were done during one of the 4 year services. It's a requirement that they're sent in at the 4 year and 8 year marks for service and that supposedly includes software and hardware updates as well as testing critical components. It might be that some of those components were added or updated manually during a service.
@Boozy The Clown I mean, the code itself is still pretty worthless. There's no grand secrets in there, the expense is the certification. The only way giving away the code would benefit competitors is if they gave it away along with a warranty that made them liable if it failed.
What's the through hole three pin device on the back of the small sot-23 daugherboard? At 11:38 or thereabouts, it looks like there is a three pin through-hole device on the external case
I don't know how it was with the old version, but the current version you turn on at the beginning of the jump day when you do your gear check. You keep it running the entire day and let it shut off itself. It not only calibrates when being turned on, but throughout the day.
Have to say, for a safety related device some the components being tacked on as they are look a bit iffy to me. Looks like they took the cheap route and chose to modding the pcb rather than respinning, or they ran out of room. That and the lack of lock on that connector........would put me right off.....!
I have to wonder if that little plastic bit Dave said was a bit of melted string wasn't actually a little seal that was covering the blade to keep moisture out and it just got pushed to one side and stuck.
I wouldn’t actually consider this safety critical system. I did a lot of jumping many years ago before these were commonplace. If you consider the statistics - I’m guessing at these - there are many tens or hundreds of thousands of jumps for every time someone is unable to open his chute. If my AAD had a 5% probability of failure it would still be 20 times safer than not having one at all. It’s not like a life support system or pacemaker whose failure may actually result in certain death. I’m sure more than 99% of these are discarded without ever activating.
The false activations happen when the AAD isnt cofigured right by the skydiver. e.g: turned on inside the airplane while already in the air... changing dropzones not paying attention to the ground level... groundlevel differences from lift off point to dropzone...
@ 4:00 Because you can land in the water (intentionally or accidentally)... Falling through clouds (even if raining) doesen`t get you wet enough. Funfact: the only time rain comes from below and goes upwards! :-)
Dave, the calibtation I doubt is for variation in atmospheric pressure, I would be more concerned that the device thought that I was landing at sea level when the landing zone is on the top of the hill... splat
Dave, It most definitely is NOT auto calibrated. People who think that are usually the ones who get accidental discharges in the plane. The jumpmaster sets the ground pressure on the ground and when you are coming down it does the double air pressure test for one reason... speed. If you are below the deploy altitude and the air pressure difference between the two samples is too high then it knows you are moving too fast and haven’t deployed the canopy. If you reach the deploy altitude and you HAVE a good chute, it knows not to deploy because the air pressure difference is a lot less. Oh and while clouds are damp, you are not allowed to jump through them. Who knows if there is a light aircraft in them. The wet filter warning is if you end up landing in water and submerge the thing. Also accidental deployments are bloody scary because if it opens in the cabin of a jump plane it can literally cause the aircraft to crash. Most small jump planes operate without the side door fitted and if the device fires, the canopy is released and it shoots around the cabin. If it gets out the open door it tries to drag the jumper through the most direct route, which is the side and tail of the plane. THIS HAS HAPPENED. So yeah... parachutes opening in a plane is scary stuff. We call them AOD’s in the UK (or did... I haven’t jumped for many years now) which is why I know about them. Here is an example where a guy is doing a static line jump when his reserve (which is where the AAD is fitted) deploys before he’s jumped. The main is on his back hasn’t even opened and then he off out the back under TWO canopies (as the main is opened by the strap to the roof). Now imagine that happening on a light aircraft. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-h4MaMH7NBAs.html
They definitely are auto calibrated. " jumpmaster sets the ground pressure on the ground" huh? No, the unit calibrates zero (ground) altitude every time it is turned on by the jumper. It then recalibrates throughout the day. You don't know what you are talking about.
Screaming at the screen at several points. 7:30 the thin cable is nicked so badly I won't be surprised if it broke internally (or even shorted out)! 8:12 all grommets and a third cap are screwed! 11:20 obviously a connector to the outside! So those are protection TVS diodes. 16:51 (almost) all the perpetrators seem to have TVS diodes! 22:22 there are no adjustable elements so that's on reason for this kind of potting! 23:02 Where's your pressure sensor die!
Pyro cable cutter, the guillotine is the top portion of the piston. An EED pressurizes the chamber like a bullet exiting the chamber of a gun, you don't want tensioned springs in this condition as it's considered always live. psemc.com/products/pyrotechnic-cutter/
The sheet metal appears to be tin plated steel. If it were copper or such, you would not have held it in hand while desoldering. i have known of the stuff for a really long time, but it seemed to be totally lost art. Anything that I seemed to find was zinc plated steel, misrepresented as “tin plate” Finally, a few weeks ago I came across the real stuff in small enough quantity for me to afford it, i.e. ounces rather than tons. I promptly made a small EMC box of it. Every bit as easy as I remembered.
1. You should really test the pirotechnic. I mean fire up :), I really wait for it. 2. Where is the power mosfets form previous video? The bootom side of PCB?
About the project you worked on was it like the one the us government tried to hide weapons caches on the sea floor for use in rapid deployment. And had flotation devices that sounded similar to yours you worked on not the one in the video.
That may be your impression but these devices are extensively and rigorously tested in the US and in multiple other countries. A buddy of mine used to oversee testing of these and other extreme reliability devices. Nothing "how ya doin" about it.
Have to ask Beyond the Press for a better high speed camera. Maybe I missed why there are external transistors and wires going back. Something to do with ESD? Also the connector may be so you can just order a new pyrotechnic end when you used it...
The early ones (Cypres 1 I believe) had ESD issues where they would lock up if the parachute rig was dragged along certain surfaces during packing. You better believe they belt-and-suspenders-ered it (is that a word? Well, it is now).
All I can think of watching this is just how stressful it would be to engineer something like this. You have to worry about making sure you absolutely don't make any mistakes, otherwise you might cause someone's death.
Not going to come loose, they press fitted it with a locking liquid during manufacture, you cut these open. Firing charge is a standard pyrotechnic match that generates very high pressure in the enclosed case, and this then drives the cutter pin, basically a piston with a o-ring seal to keep the pressure in, through the rope or wire release. Sealed during manufacture, and you need the heavy construction of the stainless steel case to contain the pressure. Very precise machining to get those tolerances absolutely perfect, and as well there is always a self test of the charge every time the microcontroller wakes from sleep, to check the connection is good. Panasonic capacitor is there to ensure, even with an ESR in the kilohm range of the main battery at EOL ( they keep terminal voltage till they are nearly dead, just ESR rises rapidly at EOL so available current drops dramatically) there is at least 2J of energy to fire the charge.
You know, I could never rely upon a device to deploy my chute. I could never feel comfortable without a manual chute release. Allies of Peace killed the Axis of Liberty. Damage control done to me....
4:16 lol Dave, Wingsuits are not hang-gliders. You can't 'Stay up there for ages.' Sure, I know you're exaggerating, but the longest wingsuit flight is (copied from Guiness Records): The longest duration wingsuit flight is 9 min 6 sec, and was achieved by Jhonathan Florez (Colombia), above La Guajira, Colombia, on 20 April 2012.
It's true that there have been plenty of saves by CYPRES and other AADs, but zero malfunctions? That's not true. Generally speaking, though, they have shown themselves to be very reliable and in general, you're safer with one on your back than without.
Yeah they were laughing about how catatonic I was. It was advances free fall so they had to snap me out of it. All I remember is thinking i was looking at a google map.
you can tell something , lifepo4 batteries what is, for example, low temperature mode can survive, whether to buy it, and how to determine what iron phosphate batteries
Could you do a video on what you worked on in the past explaining it better? I didn't understand how a heat device made something rise to the surface to make something sink.
Why is it hand soldered? I expected more solid construction, and better quality for a life saving device! All wires are mess they could use connectors on board It's high chance of short circuit with these wires any where on circuit. Don't you think so?
Dave the sensor came with a gel however its a bit uncomfortable for you to make this mistake as any high school student studying physics/hydrostatics would point out that fluids including the gel in the sensor transmit hydrostatic pressure without losses.
rohit khanna You forget that the gel is not a simple liquid or gas. Thus unless carefully chosen, it might have mechanical and/or fluid dynamics properties interfering with reliable and timely measurement.
@@digitalradiohacker Dude, chill. A soft silicone gel can be modeled as an incompressible fluid for this pressure range and therefore rohit's point is totally correct. The datasheet of the sensor, if they haven't gone for the digital version, (TE MS54XX - www.te.com/deu-de/product-CAT-BLPS0028.html) specifies a full range non-linearity of only 0,2 %, same for both the version with and without the gel.
@@digitalradiohacker I'm not a mechanical engineer, but from the electrical engineering viewpoint, the silicone gel makes no difference to the output according to the data sheet. I only argue that assuming that a silicone gel is an incompressible newtonian fluid and therefore won't have any stress gradient seems to be reasonable for this application (low frequency, low pressure range).
Two things: First you, Dave Jones, king of whining about crappy capacitors missed the gorgeous 'M' for Matsushita (present day Panasonic) electrolytic in there? C'mon mate. Second, Mylar is a PET film that is often metallized. What fell out of the can looked more like Kapton, the PEI film used in high temperature, electrically insulating applications.
@@fuuturist Ahh yes, you're right. I've seen it (albeit incorrectly) applied as an umbrella term for polyimides, though. Kind of like nylon for polyamides.
