Cadillac BST sensor camera - a bunch of N00b questions - Page 1
Forum section: electronics / general

author: Bushrod1996
author_rank: Newbie
timestamp: November 15, 2019, 03:58:03 pm
content: Hello, everyone! This is my first post on this forum.I’m a photographer. I specialized in macro images because I love investigating the flora and fauna of my own yard. But I want to try to get some financial return from my hobby and I can’t afford the equipment I’d need to match the quality of the great photographers already working in that market.I have read through the forum this morning and there is so much great information. Thank you all for sharing your expertise. A lot of the language goes over my head because, as I said, I’m not an electronics guy. So I apologize if all this information is already posted and I just couldn’t make sense of it.So I took out the hot mirror in a DSLR and replaced it with a UV fused silicon filter to experiment with UV and infrared nature images. I hope it will give my work more artistic range and marketability and at the same time the scientist in me is excited to see what secrets my yard hides in the invisible parts of the spectrum.I’m not an electronics guy but I managed it with some difficulty including breaking one connector clean off and soldering the wires to the board. Even now the replacement filter must be a little off center because I have a dark band at the bottom of my pictures. And half the buttons no longer work. But overall I’m thrilled just to be taking infrared pictures.I’ve really just begun but as I researched UV and infrared I started wanting to see beyond the spectral response of my CMOS sensor (approximately 250-1200 micrometers though I haven’t verified the limits yet).I snagged a Cadillac ElDorado infrared camera with the Raytheon BST sensor for what seems to be a good price ($80 including shipping). I think it hadn’t sold because it was listed as “non-working/parts only” but when I contacted the seller it turned out he just meant that he’s selling it as-is and doesn’t have any reason to think it doesn’t work. It should be here tomorrow.I have a few questions and I’d love any additional advice you can give.First, does anyone know the spectral response of the BST sensor? I couldn’t find specific information online. It’s categorized as LWIR and my guess is that it’s around 7000-14000 micrometers based on specs I have seen for other sensors.Second, I’m interested in covering as much of the spectrum as possible. Is there a comparably available MWIR sensor out there to cover the gap between my CMOS and the BST that you would recommend?Third, I have some 12v adapters that plug into the wall. Will those work to power the Cadillac camera or do I need a battery-powered adapter?Fourth, I saw a fantastic post from Spirit532 from 2017 in which he fabricated a chopper wheel and a lens assembly using a 3D printer to add focusing capability. Has anyone since then added focusing capability or attached other lenses to a Cadillac camera or incorporated the BST sensor into any kind of film/photography setup? Does anyone have any suggestions/hints/protips before I try?Fifth, what do I need to consider to make sure I’m seeing/recording the maximum amount of data from the NTSC composite signal? And has anyone found a convenient way to attach a portable recording device to the camera?Sixth, I gather that heat generated by the camera can interfere with the image. How seriously do I need to consider cooling? And has anyone set up a heat sink or other device in conjunction with their thermal camera?Seventh, I am trying to fashion some IR lights and reflectors for lighting my pictures. I can’t afford optical grade IR mirrors so I’m looking into various surfaces that should reflect well in at least part of the IR. I have a ceramic heat lamp that comes with a metal reflector for reptile enclosures. I have a glass bowl I’m going to spray with metallic paint. I have aluminized Mylar. I have a round silver-plated platter. I have aluminum foil. I know gold is considered the gold standard for IR reflectivity so I am considering buying a cheap gold-plated bowl. I looked into reflective safety materials but they seem to be made of polyester and glass beads which I wouldn’t particularly expect to shine outside the visible spectrum. Do any of you have experience lighting infrared photographs? Or have you noticed any materials that are highly reflective in infrared? And if anyone has a gold- or silver-plated dish at home, would you be willing to look through an IR cam and see if it’s particularly reflective?Cheers!Bushrod

author: Vipitis
author_rank: Frequent Contributor
timestamp: November 15, 2019, 08:16:01 pm
content: first of all, welcome.Gear should never limit you in marketing yourself as a photography. There are some other forum members who do nIR and especially UV photography, I am sure they will reply shortly. I myself have some nIR cameras as well as shot UV on dry plates.To me BST has a specific optical phenomenon that I dislike. Therefore my LWIR cameras are VOx and aSi. It is known as Halo, I hope you are aware of them.If you cannot find the repsonse curve online easily I am sure someone will find it. I get your idea but I doubt it matters.second, for MWIR you will need cooling for any sort of camera. So there is no cheap way to bridge the gab and it shouldn't be a priority for you, there are currently many discussions about MWIR cameras here.fifth, I am having the same question right now - here is the thread and what has accumulated so far:https://www.eevblog.com/forum/thermal-imaging/dvrs-vor-capturing-analog-thermal-video-your-experiences/there is also the "proper" way of doing it would be converting to SDI lossless and capturing that lossless. On the details of how the Raytheon BST camera core outputs the signal. there might be options to modify around NTSC all together. Use the forum search and you will find multiple threads about modifying said camera and at least one well done teardown. You might not be an electrical guy, but you will learn some things.seventh, there is a forum member that hasn't posted in a while so I will link to their Instagram. There is also two thermal imaging galleries you should look into, there are some comments on the idea of "illuminating" a LWIR image. I will include an image of me shining a LED flashlight onto a mousepad. Here is the interesting instagram post(see the rest of said account):please understand that the beauty of LWIR (to me) is that everybody is illuminating itself, therefore reflectors aren't the most improtant things. A hair dryer can be subsituted for a lamp. any flat metal (or glass) will reflect, but not in a way a reflector works in visible light as in diffusing.I wish you the best and hope the camera is functional. Feel free to search all the forum and ask more questions, I will gladly point you further as the photography is a passion of myself and I am working on making LWIR photography more possible for me.

author: Bill W
author_rank: Super Contributor
timestamp: November 16, 2019, 11:03:36 am
content: Quote from: Bushrod1996 on November 15, 2019, 03:58:03 pmThat band is pretty much what the atmosphere transmits, due to water absorption above and below it. As all parts (lens and sensor) need antireflection coatings to work at all, those coatings are optimised to the same range.It is good in that this is also the band where 'ambient temperature' objects radiate most.Bill

author: Bill W
author_rank: Super Contributor
timestamp: November 16, 2019, 11:19:47 am
content: Quote from: Bushrod1996 on November 15, 2019, 03:58:03 pmHi Bushrod,12V should be fine, but no more. Many of the BST cores had a problem with using components not good with input surges (basic grade tantalum capacitors - not surge). The core will want to take around 1Amp at strartup so you would need a reasonably robust battery supply. I would feel happier with a 9V supply.I would say a 2% fail rate for that reason alone, and near certain if connected to vehicle electrics without precautions.I have used the Raytheon core in cameras with a custom lens, in the EEV/Marconi Argus 2 and 3 firefighter cameras. Some more details here:http://www.fire-tics.co.uk/A2.htmhttp://www.fire-tics.co.uk/A3.htmObtaining close focus is just be a case of increasing lens-sensor separation. You may find that illumination calibration is no longer ideal though so you might see some contrast across a blank scene.regardsBill

author: Bushrod1996
author_rank: Newbie
timestamp: November 23, 2019, 03:24:15 pm
content: Thanks for those resources Vipitis! The camera arrived but I haven't fired it up yet. I was so excited to find it on ebay that I didn't look carefully at the picture -- the germanium filter is cracked. I think I can replace it relatively easily. I just hope it didn't get wet and corroded inside. BTW, I am @underyourskininfrared on Instagram. I'll see if I can add a link to my signature.In other news, I re-opened my camera to clean the UV fused silica filter and the problem of the black band at the bottom of the images seems to be fixed. I'm not sure what I did because the filter seemed pretty well centered even before I cleaned it.

author: Bushrod1996
author_rank: Newbie
timestamp: November 23, 2019, 03:26:07 pm
content: Thank you, Bill. It looks like I'll need to replace the germanium filter. Will I need a special coating on it?

author: Bushrod1996
author_rank: Newbie
timestamp: November 23, 2019, 03:30:29 pm
content: Thanks for the info and the links. I don't want to fire it up until I have time to give it a good inspection. Plus, I don't even know yet which wires are for power and which are for video output!! Do I need to check for anything before I connect the power in order to prevent damage?

author: Ben321
author_rank: Frequent Contributor
timestamp: November 24, 2019, 12:57:22 am
content: The title says "BTS". Sorry if I sound dumb, but what does that mean? Is that an alternative type of LWIR imager, that uses a different technology than VOx microbolometer?

author: Vipitis
author_rank: Frequent Contributor
timestamp: November 24, 2019, 02:00:53 am
content: yes, BST refers to the detector material. It works completely different to VOx/aSi microbolometers

author: Bill W
author_rank: Super Contributor
timestamp: November 24, 2019, 08:00:31 pm
content: A cracked window will not affect the camera, as long as there is no internal damage. It is not a filter, you could even remove itDo be careful with any flakes or dust, best avoided and clean up afterwardsA replacement window does need to be coated, but should be by default as they are not much use without a coating. You need coating for the 'LWIR' band of 7 - 14µm, a 'filter' would likely be narrow band.As mentioned above, best run around 10V and a 2A current limit.The main thing when powering on is to keep an eye on the current draw as this will tell you a lot of the camera health. A run up to 7W(10V/700mA) for a minute is normal as the peltier gets the sensor to temperature, you will not get much picture until the power falls back to 4W. Until then you get a mesh effect.If you can see the chopper spin up, also a good sign.Bill

author: Bill W
author_rank: Super Contributor
timestamp: November 24, 2019, 08:06:59 pm
content: Quote from: Vipitis on November 24, 2019, 02:00:53 amBarium Strontium Titanate, operates on the ferroelectric effect with incoming heat altering a capacitance causing charge flow. That is why it needs a chopper wheel, to cause the change.Bill

author: Bushrod1996
author_rank: Newbie
timestamp: November 24, 2019, 11:49:28 pm
content: Thanks, Bill. I took out the window for now. I cleaned it out and stretched some Saran Wrap in its place. I called it a filter since germanium filters out visible and NIR. I’m just thinking in photographer terms I guess.I found the specs for the sensor. It’s sensitive from about 8-14 microns but a “special optical glass” only passes about 8-12 microns. I don’t know if the “special optical glass” is the lens or the window or a coating on one or the other or some combination. Maybe if I get it up and running I can experiment with different windows to see what the effective spectral capability is.My only experience with a voltmeter is the kind you stick into an outlet to see if it’s working. Will that work for monitoring the camera’s draw? I’ll attach a picture.I am also stymied for now trying to connect the video signal. The output from the camera has a “low signal” (yellow wire) and a “high signal” (green wire) but my NTSC composite cable only has one wire. I’ll search the forum for more info that could help me with that.I can probably leave the heater wires disconnected, right? I don’t expect to do any de-icing. I wonder though if there is a thermometer in the assembly somewhere that triggers the heater.

author: Bill W
author_rank: Super Contributor
timestamp: November 25, 2019, 12:37:30 am
content: Your NTSC cable has two conductors, signal on the inner and ground / return / low on the outer. Getting that signal in reverse is unlikely to cause harm.The meter however only measures to 250mA - so won't help you. It might bend the needle !regardsBill

author: Ben321
author_rank: Frequent Contributor
timestamp: November 25, 2019, 10:59:14 pm
content: Quote from: Bill W on November 24, 2019, 08:06:59 pmVery interesting. I've got some questions about it.How does the motor synchronize on the frame rate of the camera?How does it handle negative output voltages to prevent damage to the circuit? I assume if a positive voltage is generated when the chopper opens and the camera is exposed to the hot image, a negative voltage is generated when the chopper closes and it sees a colder temperature.How is the temperature of the chopper accounted for? If the scene is colder than the chopper I assume a negative voltage is generated when the chopper opens, when the image processing circuit is expecting a positive scene voltage.If negative voltages can be handled, how is the circuit's negative voltage supply generated? I mean, the device is powered from the car it's mounted in, and the voltage from a car battery is positive 12v.How good are these cameras in terms of reducing noise, compared to other other uncooled techonologies (VOx and amorphous Si microbolometers), and compared to cooled LWIR technologies?

author: Bill W
author_rank: Super Contributor
timestamp: November 26, 2019, 12:50:38 am
content: Quote from: Bill W on November 24, 2019, 08:06:59 pmQuote from: Ben321 on November 25, 2019, 10:59:14 pmA detection point (slot or reflective dot) on the chopper wheel and an optosensor, then drive the motor from a phase locked loop IC like a 74C932 / CD4046.Quote from: Ben321 on November 25, 2019, 10:59:14 pmNot required, all shifted positive so you get a 'less positive' signal when cooling.Quote from: Ben321 on November 25, 2019, 10:59:14 pmIt isn't. The sensor is only making tiny changes in temperature about its' ambient. You cannot do direct temperature measurement with a BST.The image processing is simply subtracting each 'chopper in' image from its' 'chopper clear' predecessor.Quote from: Ben321 on November 25, 2019, 10:59:14 pmAt their time the BST image was as good as any VOx and better than ASi. The disperse/clear chopper sections also created a built-in unsharp mask function that many users liked, the BST halo around hot objects.Two videos on my fire-tics website, Argus2 and Argus 3 were BSThttp://www.fire-tics.co.uk/Argus3_CD/Video.htmMost noticeable is the total lack of any fixed pattern noise, as this is inherently absent in a BST due to the open and closed chopper fields being subtracted to give an imageBill

author: Ben321
author_rank: Frequent Contributor
timestamp: November 26, 2019, 08:19:58 am
content: What causes that dark halo around hot objects? Is that a DSP algorithm the camera uses?Also, how common is motor failure in these cameras? Are all vehicle based LWIR cameras (such as FLIR PathfindIR) using BST technology? I know the one mentioned in this thread opening post is BST, a d was stated to be from a Cadillac, but the imager model name wasn't mentioned. Was it a PathfindIR?

author: Vipitis
author_rank: Frequent Contributor
timestamp: November 26, 2019, 10:55:42 am
content: As far as I understand it, the halo is physical. And not all vehicle thermal imagers are BST. If you search for BST in this forum you will find a few threads comparing the two a d discussing history. There is an promotional "technical note" by FLIR that Google shows really far up as well.If not all, most BST sensors are Raytheon made.

author: bap2703
author_rank: Regular Contributor
timestamp: November 26, 2019, 11:06:03 am
content: I think the hot pixels leak heat to the surroundings.The sensing mechanism being differential, the neighbours sense a low infrared flux vs their own parasitically heated reference --> this is interpreted as less infrared flux vs a non heated reference.

author: Fraser
author_rank: Super Contributor
timestamp: November 26, 2019, 12:42:12 pm
content: Bill is the chap I turn to with questions on BST sensors but I remember him telling me about the Halo, chopper wheel and dynamic range of BST sensor FPA’s.From what I recall, BST pixels have limited dynamic range that necessitates the use of a mechanical iris in some camera designs. The chopper wheel is also designed to improve dynamic range in some cases. The spiral chopper wheel can be a combination of LWIR opaque and non opaque sections that effectively ‘reset’ the BST pixels to a nominal state before their next exposure to the thermal scene. The spiral chopper wheel does this in a synchronised and progressive manner as it sweeps the opaque area down the BST FPA window following the readout of the pixel rows. Hence why it must be synchronised to the row readout process. I suppose it is a bit like a rolling shutter in some ways. It was found that the performance of the BST FPA could be improved by using a combination of higher attenuation and lower attenuation sections in the chopper wheel. A thin plastic membrane was used as the lower attenuation substrate and a pattern of semi opaque dots was applied to the substrate to create the chopper wheel spiral. This means that the BST FPA sees a higher and lower signal attenuation through the chopper wheel rather than a 100% and 0% attenuation of the scene information as occurs with a fully opaque and transparent chopper wheel, as found in the Pevicon based cameras that preceded the BST sensor arrays.I understand that a ‘side effect’ or ‘feature’ of this semi opaque chopper wheel design is the halo effect that we see in many BST camera images when they view a hot object in the scene. I cannot explain the physics of that phenomenon but Bill may be able to. It could be to do with the fact that semi opaque dots are used on the chopper wheel rather than a semi-opaque coating over the whole ‘opaque’ spiral.Of note is that there are variations in the design of the chopper wheel found in BST and similar sensor technology cameras. The physical format of the chopper wheel can be different, as can the materials used to create the chopper wheel effect. The later BST based Honda(?) car mounted thermal camera used a very expensive looking Germanium disk. The Plessey 2000 camera contained a 100 x 100 pixel sensor array that also required a chopper wheel. That camera employed a chopper wheel that was a combination of opaque and Germanium prism elements. The Germanium prisms created horizontal and vertical offsets that physicaly increased the effective resolution of the cameras image. The system was called microscan resolution enhancement if I remember correctly. Very clever, and likely expensive to produce.As Bill has stated, BST sensor arrays are not capable of radiometric measurements so cameras that needed to provide real time temperature measurement often used a separate non contact IR thermometer module such as those sold by Exergen, Omega and Raytek. The temperature measurement was then displayed on the cameras display. This could cause parallax error issues and was not a true spot measurement system as found on microbolometer based cameras that use the FPA data for spot measurements.Fraser

author: Fraser
author_rank: Super Contributor
timestamp: November 26, 2019, 12:52:02 pm
content: Regarding the Cadillac DeVille BST thermal cameras..... these were made by Raytheon in 1999/2000 and based upon the proven Thermal Eye 300A circuits. Later BST based car thermal cameras like that used on the Honda(?) likely used the Thermal Eye 300D circuits in their design as it offered improved noise levels in the image.Not all car based thermal cameras used BST. It was just the technology that was available at the time for portable use. The FLIR Pathfinder is an example of a Microbolometer technology based car mounted camera.Fraser

author: Fraser
author_rank: Super Contributor
timestamp: November 26, 2019, 01:41:44 pm
content: Regarding chopper motor reliability.....I am told the motors are very reliable unless they suffer water ingress. There are two types of motor used in most Raytheon BST core kits. The coreless Faulhaber motors are excellent quality but can suffer from speed regulation issues due to the gyroscopic effects of the chopper wheel if the camera turns quickly. A CD type spindle motor was used to address this issue.

author: Bill W
author_rank: Super Contributor
timestamp: November 26, 2019, 04:36:28 pm
content: Quote from: Fraser on November 26, 2019, 12:42:12 pmThe 'opaque' section is not opaque on most versions, it is 'dispersive'. This creates a fuzzy image during the obscured field scan.open field = sharp hot objectclosed field = fuzzy warm blob.So where the hot object is, this reduced the scene dynamic.Outside the hot object, and once inverted/subtracted this gives the black halo zone.Bill

author: Ben321
author_rank: Frequent Contributor
timestamp: November 26, 2019, 07:19:51 pm
content: Quote from: bap2703 on November 26, 2019, 11:06:03 amI thought the reference was the frame when the chopper disk was closed. Assuming the temperature of the chopper disk is constant, shouldn't the image be correctly processed when the chopper opens and allows IR light from the scene to hit the sensor?

author: Ben321
author_rank: Frequent Contributor
timestamp: November 26, 2019, 07:32:31 pm
content: Quote from: Bill W on November 26, 2019, 04:36:28 pmAnd from my understanding, the subtraction just happens as part of the way the sensor material operates, right? It detects changes in heat, so the fuzzy hot area is already depleated so this "subtraction" just happens by the sensor's own operation, rather than using DSP to perform subtraction?I wonder what a BST camera image would look like, if instead of using a diffuser blocking part on the chopper wheel, it used a completely opaque blocking part? Did any BST cameras use such a chopper wheel?

author: Bill W
author_rank: Super Contributor
timestamp: November 27, 2019, 05:27:37 pm
content: Quote from: Ben321 on November 26, 2019, 07:32:31 pmThere is no DSP involved, all physical as you say. Outside the sharp hot area, the pixels only get heated in the 'closed/fuzzy' field and cool in the open field.As for a solid closed chopper, I do not think any manufacturer used it due to the dynamic range problem, but it would have produced a simple image without a halo.Perhaps Fraser or one of the other forum folks tried ?Bill

author: Cat
author_rank: Regular Contributor
timestamp: November 27, 2019, 06:17:56 pm
content: Quote from: Bill W on November 27, 2019, 05:27:37 pmThe 3D printed replacement wheel does exactly this, there is no halo. You can find different examples in this thread:https://www.eevblog.com/forum/thermal-imaging/raytheoncadillac-deville-camera-3d-printable-focusing-mod-and-chopper-wheel/msg1354096/#msg1354096

author: Ben321
author_rank: Frequent Contributor
timestamp: November 27, 2019, 07:03:19 pm
content: Quote from: Bill W on November 27, 2019, 05:27:37 pmWell before BST camera manufacturers knew it would improve dynamic range to use a diffuser like that, I'm sure they tried using a simpler design with opaque chopper. I'm sure at least a few very early BST units exist that used an opaque chopper. Anybody know if such cameras exist out in the wild? Or would those just have been prototypes in the company's R&D lab?Quote from: Cat on November 27, 2019, 06:17:56 pmSo those wheels are replacable? I'm guessing the procedure to replace them is quite difficult though.Also, I'm thinking about buying one of these myself. There's a bunch on ebay right now, all for under $500. I would like to know the specs on these though.What are the pixel dimensions of the sensor? Is it 320x240? What is the frame rate? Is it standard 60 fields per second NTSC interlaced video?And also, what is the pinout? Every single seller on ebay selling one of these units is not advertising that it comes with the connector cable, so I assume no cable is included. So I need to know the pinout, and also where to find the proprietary connector to plug into the camera, so I can build my own cable.

author: Bill W
author_rank: Super Contributor
timestamp: November 27, 2019, 11:58:56 pm
content: Quote from: Ben321 on November 27, 2019, 07:03:19 pmSimple to replace, they are either screwed to a hub attached to the motor, or simply glued on to the motor shaft.The BST is a 320x240 48um sensor, and gives out standard NTSC, or pick off digital data.The later 'all digital' core type could also do PAL but as it was simply a windowed down screen this was pointless unless you needed to use a PAL TV or recorder. Most of the UK cameras built stayed as NTSC.Can't help with car camera cables, but checking through several of the teardowns on here should cover it.Bill

author: Ben321
author_rank: Frequent Contributor
timestamp: November 28, 2019, 01:19:53 am
content: Quote from: Bill W on November 27, 2019, 11:58:56 pmInteresting. Is the digital signal just telemetry like camera temperature, battery voltage level, etc? Or is it actually digital video? If it is digital video, does it use an industry standard like USB? Or does it use a proprietary protocol, intended for use with a Cadillac video display unit?

author: Bill W
author_rank: Super Contributor
timestamp: November 28, 2019, 05:45:08 pm
content: Quote from: Ben321 on November 28, 2019, 01:19:53 amNot USB, back then USB was for keyboards only.The BST digital video is corrected 16 bit parallel greyscale digital video, plus 4 clocks. There were some overlays that you could have added, or choose none.This is how the e2v Argus 2 and 3 cameras worked, they took the datastream and then overlaid the graphics or saved captured images all in digital.The final stage was to convert to NTSC for display, Argus 3 having a rather grim NTSC LCD.I would expect that the Cadillac display was analogue as well.Bill

author: Fraser
author_rank: Super Contributor
timestamp: November 28, 2019, 06:16:23 pm
content: Cadillac “HUD” type display was NTSC composite video straight from the camera.Fraser

author: Fraser
author_rank: Super Contributor
timestamp: November 28, 2019, 06:31:34 pm
content: It may be of interest to some that the Cadillac DeVille camera appears to have been less reliable than other Raytheon BST core deployments in certain respects.......1. Mk1 Cadillac DeVille has an unsealed lens barrel to the Germanium window. Failure of the window would allow water ingress to the electronics and chopper wheel area. Corrosion results. The Mk2 model addressed this by using a sealed lens barrel. Failure of a Mk2 window resulted in only the Germanium lens front element getting wet or dirty.2. The Chopper wheel users a thin plastic membrane to create the required chopper spiral. This membrane appears to degrade in the a Cadillac deployment and splits over time. This could be a heat induced degradation.3. The chopper motor seizes if ant moisture enters the electronics area of the camera. This is usually due to a Mk1 camera suffering a broken lens protector window or a crack in the plastic bam era front due to impact in a car collision. Such damage to the camera sometimes went unnoticed or the camera was left out of use and continued to degrade over time.4. The tantalum capacitors in these cameras have been seen to fail whilst others display cracking of their casings. The tantalum capacitors are working in a relatively hostile environment and may suffer age related degradation.I have noted that all of the Cadillac DeVille cameras that have passed through my hands have been labelled as “Refurbished” and a date code. Many look to have been refurbished after just a year or two of use. This could be due to broken lens protection windows or more serious faults. Cadillac had to retrofit a grille in front of the lens protector to reduce the number of stone induced failures to acceptable levels.The Cadillac DeVille camera appears to have been somewhat of a liability to owners of the car fitted with Night Vision. This may explain why the use of the camera faded away and only recently came back in the form of the FLIR Pathfinder and Autoliv microbolometer cameras.Fraser

author: Bill W
author_rank: Super Contributor
timestamp: November 30, 2019, 04:28:14 pm
content: Quote from: Fraser on November 28, 2019, 06:31:34 pm2 Certainly the 'Cadillac' cameras are a lot worse than Argus 2 & 3 which are used in fires, but for much less run hours. Even the Argus 2& 3 see some degradation, it looks like the membrane shrinks slightly and pulls out of the frame. If the flappy edges then catch it will tear.4 With hindsight, Raytheon fitted the wrong capacitors. The ones that catch fire are standard 'TAJ' series which are not rated for surges. As an input exposed to the world you'd normally use either aluminum electrolytic or TPS series (surge rated).Fed from a soft battery supply well under voltage they likely survive but attach a vehicle '12V' line with spikes and 20A capacity ....... pop pop popOne customer fitted Argus 2's to their trucks for driving into tunnelsand they got through several processing PCB's until the build changed.Bill