EEVblog #729 - Mailbag - Page 1
Forum section: electronics / general

author: EEVblog
author_rank: Unknown
timestamp: March 31, 2015, 12:06:33 am
content: Another lengthy mailbag, with plenty of diverse stuff.RCA Airnergy Bullshit Video:Forum:SPOILERS:Kan Jam flying discPsion 3A Organiser1974 808 RapidMan Calculator made in Canada.Russian IN-9 Neon bargraph display tube.Datasheet:http://exclusiv-store.com/tubes/in-9/1745_1.jpgInfo & characteristic curves:http://www.die-wuestens.de/rd/IN9-2.pdfWifi cellphone battery charging bullshit:https://www.kickstarter.com/projects/945803481/wave-a-cell-phone-that-charges-battery-with-wifi-s/descriptionRF Energy Harvesting. Can a WiFi signal light up a LED?http://www.rfdiagnostics.comFlir VP50 Non-Contact voltage detector.Freescale PowerQuicc II security processor:http://www.freescale.com/webapp/sps/site/prod_summary.jsp?code=MPC8248EEVblog Main Web Site:http://www.eevblog.comThe 2nd EEVblog Channel:https://www.youtube.com/EEVblog2APC Netbotz Room Monitor Teardown

author: ataradov
author_rank: Super Contributor
timestamp: March 31, 2015, 12:45:59 am
content: Video is glitchy, especially on head movements up and down. Still watchable though.

author: Smokey
author_rank: Super Contributor
timestamp: March 31, 2015, 01:23:33 am
content: Wardrobe was busy today. 10 minutes in and your shirt changed 4 times

author: kizzap
author_rank: Unknown
timestamp: March 31, 2015, 01:24:30 am
content: Woah! I think Dave has been using his Delorean...He receives the shirt which he tests for static later in the video.Thanks for the video Dave!Edit: can we take a minute to mention how bad an idea it is to use a screw/washer to hold down the wires in that soldering iron?

author: EEVblog
author_rank: Unknown
timestamp: March 31, 2015, 01:26:51 am
content: Quote from: ataradov on March 31, 2015, 12:45:59 amLots of Youtube problems. Says it hasn't finishing processing yet, and will not show on my feed.

author: EEVblog
author_rank: Unknown
timestamp: March 31, 2015, 02:29:16 am
content: Re-uploaded and now processed fine. No idea what happened to previous one.

author: aargee
author_rank: Frequent Contributor
timestamp: March 31, 2015, 02:44:48 am
content: Dave:Factoid, I do not think it means what you think it means. I used to think it was a 'micro-fact' as well. Politicians are the worst at using this with some quite hilarious results if you take the meaning in it's correct context!!http://en.wikipedia.org/wiki/Factoid

author: sparx
author_rank: Contributor
timestamp: March 31, 2015, 02:51:52 am
content: That soldering iron (p.o.s) was £1.57 off eBay. I found it whilst searching for some soldering stations and after a chat in IRC, I decided why the hell not - thought it might provoke some interesting discussionMy £10 stick iron has some kind of passive ?protection devices in the handle, the only thing this iron is going to be protected by is the distribution board (Would the heater element blow before the wires started melting?)http://www.ebay.co.uk/itm/261507617086(Now increased the price!)

author: EEVblog
author_rank: Unknown
timestamp: March 31, 2015, 02:59:02 am
content: Quote from: aargee on March 31, 2015, 02:44:48 amQuoteWelcome to the living and evolving English language!

author: eV1Te
author_rank: Regular Contributor
timestamp: March 31, 2015, 03:31:34 am
content: The Keithley 2400 can sink/source up to 100 mA at 200 V. You just forgot to press the up-arrow for the current range (both compliance and source has individual ranges). That is the up-arrow button to the right of the button you were pressing

author: bills
author_rank: Frequent Contributor
timestamp: March 31, 2015, 03:56:52 am
content: The neon tubes were cool, video was just fine.

author: classical
author_rank: Regular Contributor
timestamp: March 31, 2015, 04:10:44 am
content: The ferrite chip on top of the freescale processor is a EMI Suppression CPU Ferrite Plate, e.g.http://katalog.we-online.de/en/pbs/WE-CPUhttp://www.digikey.com/product-search/en/filters/ferrite-disks-and-plates/3408559?k=ferrite%20platehttp://www.digikey.com/product-search/en/filters/ferrite-beads-and-chips/3408555?k=ferrite%20plate

author: cdonges
author_rank: Newbie
timestamp: March 31, 2015, 04:46:12 am
content: That's my psion!Psion 3a doesn't have pcmcia slots - they are proprietary you could get battery backed ram, flash or roms.Looking forward to the teardown!

author: Lightages
author_rank: Unknown
timestamp: March 31, 2015, 05:10:06 am
content: I have a Rapidman that my parents gave me in 1974, and it still works. I still have the original wall wart and manual too!

author: NiHaoMike
author_rank: Super Contributor
timestamp: March 31, 2015, 06:47:26 am
content: It's possible to use a common CCFL as a tube bargraph by bypassing the output cap on the inverter, connecting the output to one end of the CCFL (leave the other end disconnected) and to a piece of thin bare wire wrapped around or taped to the CCFL. Then supply the inverter with a variable voltage and watch the CCFL go up and down.

author: EEVblog
author_rank: Unknown
timestamp: March 31, 2015, 07:19:42 am
content: Quote from: cdonges on March 31, 2015, 04:46:12 amAh, I think my Psion 5 had a standard PCMCIA slot.

author: cdonges
author_rank: Newbie
timestamp: March 31, 2015, 07:27:54 am
content: Quote from: EEVblog on March 31, 2015, 07:19:42 amCompact flash for series 5.I had a 5 too but my girlfriend stole it and used it to do her university assignments. Happy days.

author: steves
author_rank: Contributor
timestamp: March 31, 2015, 08:30:57 am
content: Is there much of a difference between the Audiophools and the Videophools? Thanks.

author: TimFox
author_rank: Super Contributor
timestamp: March 31, 2015, 12:59:23 pm
content: Quote from: EEVblog on March 31, 2015, 12:06:33 amI purchased these units from 'Frag' Jan zuerst', and they worked as advertised. However, I found erratic operation (with disjoint glow patterns) when running them directly from a Fluke calibrator in constant-current mode. They ran well from a voltage and series resistor, but that is a non-linear circuit. I haven't tried the transistor drive yet.

author: Grecord
author_rank: Newbie
timestamp: March 31, 2015, 04:00:48 pm
content: moto-e FTW , <$< or Moto-g for even better value. YMMV

author: richfiles
author_rank: Regular Contributor
timestamp: March 31, 2015, 04:13:09 pm
content: I have a Rapidman 1208 LC desktop calculator, with an unusual rear illuminated LCD. It has a standard incandescent lamp that backlights a white on black LCD. It's just a little four banger as well.Rockwell and Texas Instruments produced the earliest LSI calculator chip sets. Many companies purchased chipsets from Either Rockwell or TI, and did their own branded designs. HP did their own models, relying on their own designs (with some early mask development and production contracted to MOSTEK). MOSTEK focused on DRAM and second sourcing microprocessors, but ultimately failed against asian DRAMs. MOS Technologies (not MOSTEK) was also a major supplier of early calculator chipsets, as well as CPUs (like the MOS 6502). Unlike MOSTEK, MOS Tech was bought by Commodore, and became a MAJOR manufacturer that shifted towards computing to survive, after calculator prices dropped. There are actually a large variety of Commodore calculators that have some impressive feature sets, all based on MOS chips.The keyboard on that Rapidman you were sent looks like one of the variants of the TI Klixon keyboard, just with smaller keycaps than is traditional. Companies could use whatever style keycap they wanted, as the Klixon was a self contained unit, more or less. Again, TI sold the part and other calculator manufacturers used it as an off the shelf component to manufacture their own models. Some companies even bought the TI keycap set (shown below) and just silkscreened whatever symbols they wanted. TI even sold the keycaps as a double shot injection molded variant! The fact that there are domes for the entire grid, even thought he entire grid isn't utilized is a solid indication that it's an off the shelf part, vs something made custom for that calc.Hmm... Klixon keyboards... I think this is a legit one, but you never know! Maybe it's a knockoff! Does the PC board say a number followed by KS anywhere, like 1KS, or 6KS?LOL, I can always use a Rapidman! XD

author: D. Head
author_rank: Contributor
timestamp: March 31, 2015, 04:39:09 pm
content: And the oscilloscope in the background is still upside-down...

author: SeanB
author_rank: Super Contributor
timestamp: March 31, 2015, 04:52:14 pm
content: Shoot, I must dig out the assorted walkmen I have and slap them in the post to Dave then. Will quadruple his collection, though I doubt any of then still work ( Sony belts.........) as tape transports.

author: richfiles
author_rank: Regular Contributor
timestamp: March 31, 2015, 04:57:12 pm
content: If I recall, the original Sony Walkman used a gearmotor rather than the typical belt. One of the old "BEAM" style robots built by Mark Tilden in the 90s was named "Walkman", for it's use of 5 first edition Walkman gearmotors to drive it's legs and center joint. Those motors fetch a high premium these days, and I imagine an original Walkman really would be a collectors item! I'd love one myself!To those who might not be aware, BEAM robots were these ridiculously simple things that used relaxation oscillators chained together to create "Central Pattern Generators" that would create semi variable walking gaits, or operate wheel motors off of the duty cycle you get from paired realization oscillators tied to either solar panels or sensors. In the late 80s and early 90s, it was kinda impressive, but it really couldn't scale, and CPUs eventually far overtook them in capability. Still, I do enjoy making them... Kinda like an electronic version of clockwork toys, in a sense.Tilden had ideas of making hundreds or thousands of the things for cheap, dropping them on active land mine zones, and letting the little robo-bugs randomly skitter about and blow themselves (and the mines) up! LOL! At least the idea was for a good cause! Now, a micro can do the same job, and still be cheap!

author: Macbeth
author_rank: Super Contributor
timestamp: March 31, 2015, 05:24:21 pm
content: Well there's a co-incidence. I just had a mailbag tuesday myself, received a parcel from Russia this very morning including some IN-9 nixie bargraph tubes.I've got an old UNI-T UT70B meter whose crystals dropped out of the cracked LCD. I'm planning on turning its guts into a bench DMM with the nixies, IN-12B's for the digits, IN-15A/B's for the symbols, and IN-9 for the bargraph function. Oh, some IN-3s for the MAX/MIN/REL indicators. I'm going proper cold war soviet on this oneOf course it will revert to Nixie Clock mode when the meter is switched offI can recommend tubes-store.com. Excellent prices (IN-9's are currently only $1.50 each!), well packaged, new unused stock, and quick delivery (within 10 days Russia to UK).

author: sergey
author_rank: Regular Contributor
timestamp: March 31, 2015, 07:11:33 pm
content: Dave, you plugged the nixie wrong way around first time by the looks of itIt is supposed to have cathode in the center pin and anode in the side pin. And yes, that was a date code. We absolutely produced nixies in 84 and think i even have ones with date code of 86.The voltages are a bit weird on them. It is supposed to start glowing at 100v and keep glowing at 70v. That's per original specifications. Not totally sure about physics happening when they're living on the shelf, but maybe they're aging? Because i've got whole bunch of IN-12 and IN-4 here and all of them are starting to glow at a different voltage.Macbeth, that a very neat resource, thanks for sharing it!

author: barnacle2k
author_rank: Regular Contributor
timestamp: March 31, 2015, 08:12:58 pm
content: Hmm this makes me want to play with my IN-13 tubes again (neon filled, orange/red glow).And yes polarity matters on these.Here another datasheet:http://www.die-wuestens.de/rb/IN9-13.pdfAnd that APC NetBotz is actually meant for datacenter / server room monitoring not home automation.Thus the industrial construction.

author: Sebzy
author_rank: Contributor
timestamp: March 31, 2015, 10:00:31 pm
content: The Netbotz monitor was used in a datacentre for 18 months before it just decided to die after a reboot, suspect it's switch mode power supply issue but thought it would be more entertaining to send it along for a tear down. Sure if you drive it from the on board DC jack it should boot up fine.

author: Len
author_rank: Frequent Contributor
timestamp: March 31, 2015, 11:42:58 pm
content: 44:30 - That RAPIDMAN may be made in Canada, but it's got an "Oz" button!

author: crisr
author_rank: Contributor
timestamp: April 01, 2015, 02:17:06 am
content: Quote from: D. Head on March 31, 2015, 04:39:09 pmMaybe to recalibrate the internal reference crystal for the southern hemisfere... no need for a fancy AGO-3000 ;-)On another topic, that WiFi cellphone charging Kickstarter has already got $50 worth of backers... if it was a flexible funding campaign maybe he could use that to buy some basic electricity textbook, or upgrade that RadioShack multimeter to a better one... yes, lots of confidence inspired by it next to the giant cardboard coil :-). Someone should pledge $5 just to be able to point that out in the comments section.

author: D. Head
author_rank: Contributor
timestamp: April 02, 2015, 04:28:49 pm
content: Quote from: crisr on April 01, 2015, 02:17:06 amIn a other mailbag-video,the new employee walks in and turned the oscilloscope upside-down.

author: Don Hills
author_rank: Regular Contributor
timestamp: April 03, 2015, 05:18:14 am
content: The oscilloscope in the background makes perfect sense to me... I'm left handed.

author: dr.diesel
author_rank: Super Contributor
timestamp: April 04, 2015, 12:04:42 pm
content: I'd love to see an EEVBlab of your calculator collection.

author: seb30
author_rank: Contributor
timestamp: April 05, 2015, 03:57:03 pm
content: Hi,The logo on the calculator CPU make me think about French Thomson CSF.SeB

author: SeanB
author_rank: Super Contributor
timestamp: April 05, 2015, 04:55:13 pm
content: I also had that thought, and Thomson did make a lot of IC's for the European market, either as custom devices or as second source. They used to be a big player, but have now seemingly concentrated on the defence and avionics market as a source of obsoletium parts. they probably are the only supplier where the ceramic package is not the most expensive part to manufacture, though I guess they have large warehouses of NOS parts sitting in sealed packaging with dessicant sachets just for the spares market.

author: richfiles
author_rank: Regular Contributor
timestamp: April 06, 2015, 02:46:48 am
content: Quote from: dr.diesel on April 04, 2015, 12:04:42 pmIf I were to ever post videos ofmy owncalculator collection... It wouldn't fit in a "blab" format!I count 39 desktop calculators just on display right now at my place! That doesn't include the pocket ones!

author: Pentium100
author_rank: Frequent Contributor
timestamp: April 06, 2015, 04:35:40 am
content: I have bought some IN-13 tubes to build an audio level meter (these will look better than magic eye tubes from further away), however, I could not figure out how to build a log converter using vacuum tubes (even with help), so now I will have to do it with transistors and opamps, then again, mounting the circuit board inside a 1U case will be easier than mounting tubes horizontally.