Raytheon BST tear up for Argus3 parts - Page 1
Forum section: electronics / general

author: Bill W
author_rank: Super Contributor
timestamp: August 05, 2021, 11:41:24 am
content: Following on from these threads:https://www.eevblog.com/forum/thermal-imaging/argus-3-(bst)-teardown-and-repairs/https://www.eevblog.com/forum/thermal-imaging/some-questions-on-how-is-working-the-peltier-module-of-an-argus-3/http://www.fire-tics.co.uk/project3/index.htmhere are the details of making a customised core / camera using the Raytheon BST core from an Argus 3.DISCLOSURE - I have a few to sell !Much of this is the same as on fire-tics but easier to ask questions in context here.This can be built as either a simple volts in - video out camera, with custom setup available by RS232, up to taking in the 40 way digital data / control bus and doing what you like.The sensor is the Raytheon BST 320x 240 and here is fitted with a 15mm lens for 50° field of view. The core fits inside a 'brick' of frontal area 125x184 mm, 70mm deep including the standard lens. The chopper diameter is 70mm and is fully enclosed within the frontal area.You can fit any other lens you fancy.First the basic pictures and dimensions

author: Bill W
author_rank: Super Contributor
timestamp: August 05, 2021, 11:44:16 am
content: Now some images to outline the electronicsThe basic power in / video out connection and the RS232 control connectionA guide to the functions of the PCB.

author: Bill W
author_rank: Super Contributor
timestamp: August 05, 2021, 11:50:58 am
content: There are a couple of modifications needed to a board set straight from an Argus3.For power in, although an explicit power and video connection is present on the detector PCB as a 6 pin 0.1" header PL11, on a 'used' PCB from a camera the bottom 3 pins are cut off to avoid case shorting so will need replacing to suit the end recasing.Next the issue of 5V power.The 5V regulator on the detector board was powered from the 10V supply used for the LCD in the rest of the camera. By fitting a 0R0 or wire link at R66 this will join the '10V' input to the main input power 'V+'. This arrangement will require a minimum input voltage of 7.5V, a little higher than V+ would otherwise work from.Power In . Video outThe connections are shown above.The boards DO NOT include reverse polarity or spike protection. Protection should be considered if the core is not powered from a clean DC supply. A number of 'DIY' conversions of Argus3 into vehicle use have failed as car alternator spikes will kill the BST core, mainly through poorly specified tantalum capacitors. At startup there is a power surge at 10W until the sensor peltier control has stabilised. In normal running, power draw drops to around 3.5W.Again due to those fragile tantalums, keep V+ below 10VControlThe next task is bypassing or replicating the controls from the Argus Control PCB. In a full Argus3, the control of the core 'contrast' and 'brightness' is via analogue voltages to the BST SECCA PCB set by a quad DAC on the Argus Detector PCB, this being a hang-over from the older 'Analogue' BST core. Cores taken from Argus3 cameras will be set up for DC control, and note that without the Control PCB a core will give a blank image (All DAC 5V, which is DAC control with zero gain / offset).The simplest option, requiring no ongoing circuitry, is to reset the core to 'computer' control with either fixed or automatic gain using the Raytheon control IR software, for which the core RS-232 needs to be connected. The RS232 connections are shown above.All these connections are also present on the 40 way connector, as well as a lot more, but that is all for today. Questions ?Bill

author: ArsenioDev
author_rank: Frequent Contributor
timestamp: August 05, 2021, 02:39:06 pm
content: Bill, in a fit of boredom I've been slowly reversing the BST array mode of operation and creating CAD models with the end goal of throwing away the old control boards and using my own customized versions.

author: Bill W
author_rank: Super Contributor
timestamp: August 07, 2021, 09:44:53 am
content: A block diagram of the detector PCB.Note that although I can publish the 'EEV' parts, I cannot publish the Raytheon side of things. That has to be considered a 'black box' that migically runs the sensor, accepts instructions and outputs digital and analogue video.Bill

author: Bill W
author_rank: Super Contributor
timestamp: August 07, 2021, 09:58:28 am
content: Now a bit more about the 40 way connection option.This was the connection as used in the Argus3 camera, and is a standard 0.1" pitch Harwin connector. The 6 way as mentioned a few times before was a test / export compliance feature.The 40 way has:RS232 core controlPowerIn the camera was raw battery (5xNiMH / 8 x AA) for the core and 10V for the 5V rail picked off the display power, itself a switcher. As with simple operation above if linking the power rails through R66 to use a single supply keep in mind the 5V regulator headroom.Analogue video outNormally NTSC, but there is a PAL windowed mode available via the RS232Digital videoDigital video out, 10 bits data and 6 timing signals.Extra controlsSome pure 'Argus' control itemsA peltier circuit interrupt to stop things getting nasty if the camera got too hot and also to aid slow start on batteryThe SPI bus to the DAC / PLD.A thermistor on the heatsink.Argus3 had a micro on the 'Control board' connected through the 40 way to control the core video levels via the analogue control method, not over RS232, while the PLD had adjustable iris functions.Bill

author: Bill W
author_rank: Super Contributor
timestamp: August 07, 2021, 11:14:41 am
content: Image below of my adaptor for the 40 way connection to the core.Bill

author: Bill W
author_rank: Super Contributor
timestamp: August 30, 2021, 11:15:00 am
content: Have put 3 of these cores up in 'for sale':https://www.eevblog.com/forum/buysellwanted/fs-raytheon-bst-thermal-cores-320x24060hz-(ukeu27-only)/msg3655645/#msg3655645Bill

author: Fraser
author_rank: Super Contributor
timestamp: August 30, 2021, 11:24:20 am
content: Bill,Your link has fallen victim to the forums annoying hot link detection failure and gives a 404 errorFraser

author: Bill W
author_rank: Super Contributor
timestamp: August 30, 2021, 04:45:16 pm
content: link changed in post ablve - so avoid having a "/" in your thread titlesBill

author: evgeek
author_rank: Contributor
timestamp: August 31, 2021, 05:18:22 am
content: Thanks for the tear up deatails. I am looking for a rs-232 cable for Argus 3 camera (yellow trim). I see a small circular connector (lemo?) with 5 pins the front. is it the rs-232 port? i searched forums, i couldn't find details for details for that 5 pin connector. Not sure if this cable would workhttps://www.ebay.com/itm/383595613238?

author: Bill W
author_rank: Super Contributor
timestamp: August 31, 2021, 04:56:57 pm
content: The 5 pin is the RS232 but it is not Lemo, it is Fischer part Se102A054-130/4.3NiWe used the same lead on Argus2 and also some of the later video receivers that needed RS232. I do not see that part in distribution though. For home use I would suggest replacing the camera socket with something more standard. All the wiring is labelled up inside on Argus3Here is a drawing for the lead anywayBill

author: Fraser
author_rank: Super Contributor
timestamp: August 31, 2021, 06:09:46 pm
content: I can report that Fischer connectors are a bit of a nightmare to source. I am changing them to LEMO in units that I need to connect to. The LEMO series are a close equivalent in terms of fitment but are far more common, if still a little expensive ! At least LEMO connectors are available new and used on eBay. I recently changed out a 10 pin Fischer connector on a DIOP lens for this reason and fitted a LEMO socket equivalent in its place.

author: Fraser
author_rank: Super Contributor
timestamp: August 31, 2021, 06:15:20 pm
content: I just found some Fischer 102 series 5 pin plugs on eBay. They MAY be the correct one but best to check part number with the seller. Not inexpensive at £15 each, but this is not surprising for professional connectors, they tend to be very expensive.https://www.ebay.co.uk/itm/164472455163?hash=item264b527ffb:g:kVMAAOSwp19fl~-O