EEVblog #936 - Mailbag - Page 1
Forum section: electronics / general

author: EEVblog
author_rank: Unknown
timestamp: October 24, 2016, 10:49:15 pm
content: Old component bonanza Mailbag!SPOILERS:TI-74 BASIC pocket computer teardown from 1985OpenMYR WiFi Motor Kickstarterhttps://www.kickstarter.com/projects/77886650/wifi-motors?token=9aa90ab1Several 4-banger calculatorsGEZE automatic roller door controller teardownE-Book reader teardown and PCB bypassing techniques,http://www.switchandlever.com

author: Andy Watson
author_rank: Super Contributor
timestamp: October 24, 2016, 11:29:19 pm
content: Ace! Love to see more research on the glassware stuff.I'm pretty sure the first unknown piece was a Dekatron, or similar counting device.

author: jonovid
author_rank: Super Contributor
timestamp: October 25, 2016, 01:06:55 am
content: Quotegeiger counter type tube 9:55Dekatron Counter Tube 7:15

author: McBryce
author_rank: Super Contributor
timestamp: October 25, 2016, 08:01:34 am
content: The metal/glass component at 12:55 is an LDR (Light dependent resistor) as used to switch on street lights.McBryce.

author: cj
author_rank: Contributor
timestamp: October 25, 2016, 11:16:04 am
content: The tube at time index 7:17 looks a lot like a “leuchtquarz”, translated light emitting quartz crystal. If the quartz is resonated with sufficient amplitude it should light up just like a small neon bulb.The tube at time index 9:47 is definitely a photomultiplier.A Google search results in type numbers FS9-P10F, FS9-P10S, VFS950F or VFS910FI have a small collection of similar glassware. It’s always interesting to see what they used to put in vacuum or gas filled tubes.CJ

author: bktemp
author_rank: Super Contributor
timestamp: October 25, 2016, 12:39:38 pm
content: Quote from: cj on October 25, 2016, 11:16:04 amVery interesting. I have never seen a quartz crystal combined with a neon bulb before.They seem to need quite some power (50-100V at the correct frequency (<0.1%) to light up. You can even see multiple dots when driven at harmonics.Maybe it is time for a followup video playing with those tubes. It would be probably the first video on Youtube showing a working "Leuchtquarz".Some of the tubes should be pretty easy to drive (like the filament displays). The dekatron needs some more circuit to make it counting, but it would also be interesting.SEL is short for Standard Elektrik Lorenz, a former German electronics manufacturer. But Dave is right, the device is a selenium rectifier (rated for 60V 300mA).What is the device at 10:30 and the device at 13:00?

author: jonovid
author_rank: Super Contributor
timestamp: October 25, 2016, 12:39:52 pm
content: Quotegeiger counter type tube 9:55I stand correctedYes its a photomultiplier I now see the number of pins on it. had advertising for photomultiplier tubes in my Dad's Electronics AustraliaEAmagazines. as for the WiFi Motor , Open Source platform that anyone can use.our pets can do with WiFi controllable feeders.if Chinese hackers over feed the cat will it be a catastrophe

author: NivagSwerdna
author_rank: Super Contributor
timestamp: October 25, 2016, 02:09:50 pm
content: 35:00 I think he's trying to tell you he knows where his towel is.

author: dexters_lab
author_rank: Unknown
timestamp: October 25, 2016, 03:17:59 pm
content: Quote from: bktemp on October 25, 2016, 12:39:38 pmstruggling on that one too, interesting though the number of pins match the row and column countcome on Dave... extreme teardown time!

author: rollatorwieltje
author_rank: Unknown
timestamp: October 25, 2016, 04:05:56 pm
content: It's this thing:http://www.radiomuseum.org/tubes/tube_dm12-9-3.htmlDiode grid for driving a display using DTL.

author: bktemp
author_rank: Super Contributor
timestamp: October 25, 2016, 04:39:15 pm
content: Quote from: rollatorwieltje on October 25, 2016, 04:05:56 pmInteresting. Time for extreme teardown.It would be interesting to see how they packed all the diodes into that module. Is everything on a singe chip, or did they use individual diodes?

author: PA0PBZ
author_rank: Super Contributor
timestamp: October 25, 2016, 07:06:49 pm
content: This smellshttps://commons.wikimedia.org/wiki/Special:Contributions/Binarysequence"Own work" sure, getting the screenshots from YT. And there's more further down the list.

author: rollatorwieltje
author_rank: Unknown
timestamp: October 25, 2016, 07:18:53 pm
content: Quote from: PA0PBZ on October 25, 2016, 07:06:49 pmYes, Dave is ripping off his own videosAll those pictures have the exif information of his camera, a screenshot of Youtube wouldn't have that.

author: PA0PBZ
author_rank: Super Contributor
timestamp: October 25, 2016, 07:22:55 pm
content: Quote from: rollatorwieltje on October 25, 2016, 07:18:53 pmWTF... Binarysequence is Dave? Someone should have told me that before I made a fool of myself!

author: drjazz
author_rank: Newbie
timestamp: October 25, 2016, 07:42:41 pm
content: the item at 11:30 is a selenium bridge rectifierhttp://www.semicon-data.com/diode/dsl/B30C600.html

author: MartinX
author_rank: Regular Contributor
timestamp: October 25, 2016, 08:14:54 pm
content: The Hugin calculator is not made in Sweden it is rebranded by Kooperativa Förbundet, Hugin still is one of their labels, I have a Hugin branded vacuum cleaner. The label says "IMP" in the corner, that is not to offend short people it stands for imported, it is probably made in Japan.The only Swedish company to make calculators in any numbers were Facit as far as I know and they didn't last very long, the Japanese manufacturers totally killed them.

author: TassiloH
author_rank: Regular Contributor
timestamp: October 25, 2016, 08:18:04 pm
content: Quote from: bktemp on October 25, 2016, 04:39:15 pmI remember that I took one apart as a kid. I vaguely remember that the plastic contained stamped metal contact strips for the matrix, and at each connection point a little spring and something too small to identify (probably the diode as bare die, or point contact diode formed together with the spring).

author: tzok
author_rank: Regular Contributor
timestamp: October 25, 2016, 09:55:22 pm
content: I have a very similar calculator, but mine is from Germany (probably West Germany), and is a simple "four-banger". It is MBO branded, "de Luxe I" model:I've also found a photo of MBO de Luxe IV, which is identical to one on the video... so apparently it was some "generic" calculator sold under different brands around the world.

author: Halcyon
author_rank: Unknown
timestamp: October 25, 2016, 11:27:45 pm
content: One of those tubes (at 6:43) looks like avideo camera tube(or Vidicon tube).

author: bktemp
author_rank: Super Contributor
timestamp: October 26, 2016, 04:57:03 am
content: Quote from: TassiloH on October 25, 2016, 08:18:04 pmSounds like the matrix is easily "reprogrammable" by rearranging the diodes.

author: rrinker
author_rank: Super Contributor
timestamp: October 26, 2016, 05:01:41 pm
content: Only if your name is Neo

author: PA0PBZ
author_rank: Super Contributor
timestamp: October 26, 2016, 06:25:49 pm
content: Quote from: rrinker on October 26, 2016, 05:01:41 pmIt sounds more like "Once you open the unit the diodes will jump out all over the place and you're screwed" but if anyone wants to try...?

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: October 27, 2016, 02:56:49 am
content: OOooh, love those flatpack ICs in their colorful plastic holders! Betcha those are Philco.Man I'd love a few of those chips. One to crack open and look inside.

author: fusebit
author_rank: Contributor
timestamp: October 27, 2016, 05:58:57 pm
content: I like the filament display, they look nice in operation!

author: CoolKoon
author_rank: Newbie
timestamp: October 30, 2016, 02:29:54 pm
content: Just an FYI for the Tesla branded chips (visible around6:07): they have been made by THE electronics (both consumer electronics and parts) manufacturer in Socialist Czechoslovakia (the only such company and state-owned as everything else) named after the Serbo-Croatian-American inventor Tesla. Their product range was pretty impressive (minus more complex ICs, most of which had to be "imported" i.e. smuggled in from western countries), their specs less so. IIRC the company was privatized after 1989, with some divisions going bankrupt afterwards and some remaining, but AFAIK the Tesla brand has not been used by them for at least 15-20 years.

author: SeanB
author_rank: Super Contributor
timestamp: October 30, 2016, 02:50:15 pm
content: Quote from: Alex Eisenhut on October 27, 2016, 02:56:49 amThose would be either Ti or Fairchild, and as a trap the pinout for the PM3 flatpack is almost always different to the DIL package pinout, though the actual die inside is the same, and the sequence of pins is the same, just the power and ground pins are the shortest ones in the middle of the package, not the more common DIL version where they are top right and bottom left.crDSC01484bySeanB_ZA, on FlickrAs to the 4 bangers, those are cost optimised to the extreme, with the boards being single sided so they could be screen printed with the india ink conductors, then copper plated ( saved copper on the board, and you use a much thinner board) and then there was a punch die that both cut the finished boards out of the panel and cut the joins that made the plating possible ( the 2,3 or more thin traces leading to a hole in the board, or off the edge) so you make a very cheap but very reliable board. The screen printed resist and the silver loaded epoxy screen jumpers as well are quite reliable, and also can be done on the large panel before punching, making it possible to do 100 boards at a time in a single pass through the drying oven.

author: Fallingwater
author_rank: Contributor
timestamp: November 22, 2016, 03:31:18 pm
content: Bookeen emerged as a respectable manufacturer in the early days of eBook reader. We're talking ancient history here... TEN years ago! *gasp*Kindles were yet to become a thing, and the e-paper market was largely dominated by Sony's early offerings - with excellent hardware but proprietary and intentionally crippled software, in the great Sony tradition of ineffectually blocking anything that could plausibly be pirated.When others started entering the market Sony employed their well-honed process of trying to ram crippled products down people's throats anyway and only facing reality and releasing products that actually worked much too late - because that had worked so well a few years earlier in selling more mp3 players than Apple and Creative.In any case the market was left wide open to the competitors, who all had worse hardware but readers that didn't require you to jump through absurd copy-protection loops to read your ebooks - which was important because at the time most peoplewereactually reading pirated content, digital delivery being in its infancy.It didn't take long for Amazon to start flexing its muscles and developing the concept of the store-dependant device, but in the meantime a smattering of smaller manufacturers brought their own e-readers to market, and Bookeen was probably the most successful of them until Kobo came around. Then Amazon dropped the price of the basic Kindles to impulse-buy levels and that was that, but before that happened Bookeen actually made some decent readers.I myself have a Bookeen Cybook Opus as my own e-reader; I bought it six years ago for 110 euro (on a special sale - it used to cost 150), use it daily and have never felt the need to replace it - it's very basic, but it's small and easily pocketable and does its one job perfectly fine.Bookeen themselves still exist, but they can't be in good shape; their ebook sales service is basically unknown, their last reader was announced in 2014 (and even that didn't receive stellar reviews), they've vanished from offline store shelves and Amazon and Kobo have stolen all the market. I've seen some local rebrands being sold recently that look suspiciously like the Opus; I suspect Bookeen gets all its current profit from licensing its designs to rebranders, though even that can't be much because the rebrands themselves aren't actually cheaper than Kindles.