EEVblog #733 - Mailbag - Page 1
Forum section: electronics / general

author: EEVblog
author_rank: Unknown
timestamp: April 15, 2015, 12:00:47 am
content: Mailbag time again.What have people sent in this week?SPOILERS:AUD$5500 10k resistor in a box!http://wekomm.com/metrologie.phpXeon ECC server memory galore!AC/DC Back To The Future T-Shirt:http://www.enteetee.com/product/back-in-time/HeartSine Samaritan Pad Heat DefibrillatorK band radar systemForrest Mims Radio Shack booksForrest Mims Amp Hour Interview:http://www.theamphour.com/171-an-interview-with-forrest-mims-snell-solisequious-scientist/Silicon Labs $30 EFM8 8bit 8051 development boards:Sleepy Bee:https://www.silabs.com/products/mcu/8-bit/Pages/efm8-sleepy-bee-starter-kits.aspxBusy Bee:https://www.silabs.com/products/mcu/8-bit/Pages/efm8-busy-bee-starter-kits.aspxUniversal Bee:https://www.silabs.com/products/mcu/8-bit/Pages/efm8-universal-bee-starter-kits.aspxhttps://www.silabs.com/Support%20Documents/TechnicalDocs/Si7021-A20.pdfMaxim 11300 ADC/DAC evaluation board:http://www.maximintegrated.com/en/products/analog/data-converters/analog-to-digital-converters/MAX11300PMB1.html

author: hli
author_rank: Frequent Contributor
timestamp: April 15, 2015, 02:19:49 am
content: The 'AEM' setting on the Silabs boards is the 'Advanced energy monitoring'. Its already on the EFM32 boards, and allows not only real time current consumption measuring, but also correlation with the source code that causes the current consumption (using theEnergyAware profiler). Thats why there is no seperate current measurement jumper on the boards.

author: EEVblog
author_rank: Unknown
timestamp: April 15, 2015, 03:19:12 am
content: Quote from: hli on April 15, 2015, 02:19:49 amAh, awesome!

author: Armxnian
author_rank: Regular Contributor
timestamp: April 15, 2015, 07:26:08 am
content: More religious and political discussion in the comments...Athiesm is the disbelief in god yet no one can actually 100% prove there is no god. On the other hand no one can prove there IS a god. Stupidest discussion ever.Politics is a joke, especially in the U.S.EEVblog should be a place to get away from all this crap, why even mention it.

author: RobertHolcombe
author_rank: Frequent Contributor
timestamp: April 15, 2015, 07:39:22 am
content: Dave, can we see the photos of the 10k transfer standard, or are you saving them for the video you mentioned?

author: GoneTomorrow
author_rank: Regular Contributor
timestamp: April 15, 2015, 12:33:21 pm
content: Will be interesting to see what happens with the new memory in the Xeon rig. The main issue with what you had was potentially inadequate memory bandwidth, rather than amount. The CPUs support four memory channels for highest throughput, and you need at least four matched DIMMs per CPU (1 DIMM per channel, might be different for Xeons though).Fully populate that sucker with matched DIMMs and give it a burl

author: Royce
author_rank: Contributor
timestamp: April 15, 2015, 12:59:26 pm
content: With all that memory, perhaps you can render raw to a RAM drive and then HandBrake down to a real disk?

author: DanielS
author_rank: Frequent Contributor
timestamp: April 15, 2015, 01:06:31 pm
content: Quote from: Royce on April 15, 2015, 12:59:26 pmIt does not really matter, first because the write/read rate is so slow compared to HDD/SSD speed and secondly, with this much memory, all recently read or written files will still be in the OS' disk cache so there won't be much of a performance penalty at all. If Dave wants to keep his intermediate files, having to copy the file back from RAM-drive to HDD will waste more time than what little performance loss he might get from writing intermediate output directly to HDD.

author: EEVblog
author_rank: Unknown
timestamp: April 15, 2015, 01:09:24 pm
content: Quote from: Armxnian on April 15, 2015, 07:26:08 amThey aren't equally likely options. There is only one side making outrageous and silly claims.QuoteIt's my channel, I get to say whatever I wantNo one has any right to NOT be offended/upset/annoyed at what I say. Nor do they have a right to expect me not to say or talk about something.It's not the first time I've mentioned religion and it probably won't be the last.

author: EEVblog
author_rank: Unknown
timestamp: April 15, 2015, 01:09:54 pm
content: Quote from: RobertHolcombe on April 15, 2015, 07:39:22 amDidn't I overlay them in the video?

author: EEVblog
author_rank: Unknown
timestamp: April 15, 2015, 01:11:22 pm
content: Quote from: Royce on April 15, 2015, 12:59:26 pmOnly for short videos. A 1 hour video I think would need about 700GB or something.Can try different "raw-ish" codecs though.

author: FrankBuss
author_rank: Unknown
timestamp: April 15, 2015, 02:11:55 pm
content: The 10k resistor looks nice. Compared to the price of it, the case they sell is a bargain for EUR 490 and looks like it has even room for two resistors:http://www.datatec.de/wekomm-RS9010A-CASE-Widerstandsnormale.htmAnd they are selling a 1 Ohm resistor, calibrated with 0.1 ppm accuracy. But how does it work? I would expect a nice datasheet for this price, but can't find it on the webpage. Why does it have 5 sockets? I guess for Kelvin sensing? Otherwise it would make no sense for 1 ohm because the contact resistance of the sockets would be significant for 0.1 ppm (could be already a problem for the 10k resistor at this accuracy). But even then it could be a problem for some applications, if you really need 1 ohm in the circuit and can't use the other two terminals. And the green socket for shielding?

author: Fungus
author_rank: Super Contributor
timestamp: April 15, 2015, 02:45:44 pm
content: Quote from: Armxnian on April 15, 2015, 07:26:08 amYet the religiousalwaysuse that as their "argument" (in quotes).Quote from: Armxnian on April 15, 2015, 07:26:08 amOTOH you *can* pretty much prove that the Bible is a load of rubbish, eg. Great Roman census that made Mary+Joseph travel to Bethlehem? Didn't happen. Also read Exodus 20 and contrast with Exodus 34, what the hell happened there...?Yeah, sorry for bringing it up.OTOH this is good news because we can finally shut up the people in the other thread who insist the problem with Dave's video rendering machine is the RAM. Is RAM a religion? You'd think so if you read that thread.

author: free_electron
author_rank: Super Contributor
timestamp: April 15, 2015, 03:16:23 pm
content: oh god, not the god discussions again ...i will become a believer in whatever god stops these god discussions.

author: Fungus
author_rank: Super Contributor
timestamp: April 15, 2015, 04:17:10 pm
content: Quote from: free_electron on April 15, 2015, 03:16:23 pmI don't expect there'll be much 'discussion' here.

author: RupertGo
author_rank: Regular Contributor
timestamp: April 15, 2015, 05:04:35 pm
content: Since in these days of excellent computation there's no need to have an 'exact' 10k reference resistor, why bother to try? Is there a physical configuration of a particular compound that will give an intrinsically exact resistance, whose absolute value doesn't matter? My imperfect understanding of carbon nanotubes is that they have modes whereby there are step functions in resistance rather than linear changes, and that there are conduction modes that are independent of temperature, so perhaps there are systems that give resistance as a function of atomic structure or similar.(Could call it the General Ohmic Denominator, or GOD for short...)

author: Fungus
author_rank: Super Contributor
timestamp: April 15, 2015, 05:16:29 pm
content: Quote from: RupertGo on April 15, 2015, 05:04:35 pmI once bought a second-hand 10k resistor off eBay for $6.

author: Armxnian
author_rank: Regular Contributor
timestamp: April 15, 2015, 05:55:58 pm
content: Quote from: EEVblog on April 15, 2015, 01:09:24 pmFighting it makes them more angry. It will die off as people learn to think for themselves.QuoteYeah well its distracting.Quote from: mojo-chan on April 15, 2015, 01:41:32 pmWhich means debating if there is a teapot orbiting Jupiter would be a stupid discussion. You just proved my point.Quote from: wilfred on April 15, 2015, 01:47:17 pmIt is the same as disbelief. If there was no religion, Athiesm would not exist. If the initial basis was that there is no higher power, calling yourself Athiest would not make any sense. Athiesm solely exists because there is religion, meaning it is the idea of proving the other side wrong, which is impossible.Quote from: Fungus on April 15, 2015, 02:45:44 pmChristianity isn't the only religion. Being religious in theory can mean that there is a possibility of a god that no one has yet mentioned. The idea of god is impossible to disprove. You can't disprove that which isn't there or is there but hidden. Therefore, it is more logical to not follow any religious beliefs and to live your life as you see it.

author: FrankBuss
author_rank: Unknown
timestamp: April 15, 2015, 06:05:35 pm
content: Quote from: Fungus on April 15, 2015, 05:16:29 pmI once bought a 10k resistor from Digikey for 2 centsBut you are right, absolute value doesn't matter, the temperature coefficient is important. You can get 0.2ppm/°C for 10 EUR:http://www.digikey.de/product-detail/de/Y162910K0000F9R/Y1629-10.0KECT-ND/4333513So I wonder why does it cost EUR 3750. Calibration might cost EUR 100, if done for different temperatures, a good quality box, shielding, wiring and mounting another EUR 100. Does it have special aging characteristics or some other features that makes it so expensive? Or is it just because of the low production volume and people who needs them don't care about the price?

author: SeanB
author_rank: Super Contributor
timestamp: April 15, 2015, 06:18:54 pm
content: There is a good chance that that Australian $1 coin was minted in South Africa, as our mint does coinage for many countries, using that same bimetal copper coated blank.The US $1 coin has some history on it, the US mint was offering them to collectors at a discount ( selling them for 90c each IIRC) with free postage, and were accepting credit cards as payment, with shipping to anywhere in the USA at the US Treasury's cost. They found out that people were buying $1000 of coins, getting them delivered and then simply handing them in at banks for paying the credit card ( or using stolen cards and a drop shipper as well) thus getting a 10% loan, and even collecting reward points from the card providers.Info here...http://riskology.co/the-day-i-bought-15000/http://www.npr.org/blogs/money/2011/07/13/137795995/how-frequent-fliers-exploit-a-government-program-to-get-free-trips

author: Fungus
author_rank: Super Contributor
timestamp: April 15, 2015, 09:01:22 pm
content: Quote from: Armxnian on April 15, 2015, 05:55:58 pmTrue, but it's the one that's currently deeply ingrained in the biggest superpower in the world. Making polices. Deciding educational curriculums, removing all signs from the Grand Canyon that say it's "millions of years old", etc.As Dave noted, you can expect to see a gay president long before an atheist president in the USA.As far as religions go, it should be top of the hit list.

author: Fungus
author_rank: Super Contributor
timestamp: April 15, 2015, 09:05:07 pm
content: Quote from: FrankBuss on April 15, 2015, 06:05:35 pmSeems expensive to me as well. It only has one more digit than my $6 second-hand resistor. I bet if you bought a bunch of those you could find one with the extra digit then re-sell the others.Most likely it's priced to fit the target market.....and I can't believe Dave isn't going to take it apart! WTF!

author: eV1Te
author_rank: Regular Contributor
timestamp: April 15, 2015, 09:42:56 pm
content: Quote from: Armxnian on April 15, 2015, 05:55:58 pmI agree with wilfred; Atheism is NOT an "active" disbelief in God, and does NOT mean that the person wants to prove the other side wrong. Trying to prove something is related to gnosticism, meaning that "you" know that god does not exist or "you" know that god exists, depending if you are a Theist or Atheist (gnosticism comes from the word meaning "knowledge").An atheist is simply a person that is not actively believing any God, it might for example be because no one has ever introduced the concept of religion to that person, which means that the person has nothing to prove/disprove or disbelieve in the first place.There is however a small minority of atheists who make quite significant noise in debates about religion, which probably confuses people to belive that all atheists are militant opposers of all religions.But most of all I strongly believe in the statement Armxnian mentioned"EEVblog should be a place to get away from all this crap, why even mention it."

author: Armxnian
author_rank: Regular Contributor
timestamp: April 15, 2015, 10:34:42 pm
content: Quote from: eV1Te on April 15, 2015, 09:42:56 pmI have some things to say in regards to others, but I'll follow my own advice and not continue the discussion.Talking about electronics is much more fun anyway

author: N2IXK
author_rank: Frequent Contributor
timestamp: April 15, 2015, 11:21:52 pm
content: http://www.godoffmoney.com/

author: miguelvp
author_rank: Super Contributor
timestamp: April 16, 2015, 01:31:17 am
content: All y'all are funnyNow, go build something!

author: Nerull
author_rank: Frequent Contributor
timestamp: April 16, 2015, 01:46:18 am
content: I don't have any experience with that make of AED, but a brand which shall remain nameless contains 2 100uF caps potentially charged to 1.8kV, so watch what you touch. They're capable of delivering about 300J to the pads or the unlucky service tech. If these are built to be serviced they should have discharge points on the PCB for use with a sufficiently beefy resistor.Your heart generally doesn't just stop like it does in movies, and if it does an AED won't help you. The automatic part of AED means that the AED analyses the heart rhythm of the patient and will only deliver a shock if needed. Many don't even have buttons, all you have to do is apply the pads. In addition to the text instructions, it should have voice prompts to walk you through the steps. There are more advanced models for EMTs and hospitals which allow a shock to be delivered manually but most AEDs don't have that ability, or make it normally inaccessible.Most also really don't like delivering a shock without a load and if you do manage to get it to shock with nothing connected its likely to blow the ass out of the board.

author: Fungus
author_rank: Super Contributor
timestamp: April 16, 2015, 08:50:59 am
content: Quote from: eV1Te on April 15, 2015, 09:42:56 pmSome atheists don't think that religion is a harmless hobby. Religion is often a recourse for manipulative people to bully the ignorant (when I hear ignorant people spouting religion I usually wonder who fed them all that stuff and why).Righteous warscost trillions of our $$$ and hold back civilization.Imagine if that money had been spent on energy research or whatever - the world might be abetterplace.(And there'd be more jobs for electrical engineers to work on exciting new machines! Yay!)

author: tszaboo
author_rank: Super Contributor
timestamp: April 16, 2015, 10:03:19 am
content: Quote from: FrankBuss on April 15, 2015, 06:05:35 pmDidnt Dave say that it is calibrated against the Grerman national standard? IDK, I think calibating this must cost more than 100EUR, I have resistors at work which cost few hundred euros to calibrate.I guess with this 10K (and a 10V Vref) you can calibrate a 3458A which is also a few hundred euros. If you need to calibrate a 3458A on a daily basis (to get 2ppm on most ranges), it might be worth having one of these.Dammit I should make a company making cal equipment.

author: iva
author_rank: Contributor
timestamp: April 16, 2015, 10:20:16 am
content: Quote from: FrankBuss on April 15, 2015, 06:05:35 pmAnd it's 0.05 ppm/°C between 0 and 60 °C!Thanks for the link to the part, the datasheet is interesting and has a nice figure explaining the trimming, I learned something todayPS Does Digikey sell to private customers in Germany?

author: tszaboo
author_rank: Super Contributor
timestamp: April 16, 2015, 11:03:33 am
content: Quote from: iva on April 16, 2015, 10:20:16 amNo. That is Vishay first page marketing BLLSHT. These are 1.8PPM resistors, unless you bin them. Check Table 1 on the second page.

author: EEVblog
author_rank: Unknown
timestamp: April 16, 2015, 11:08:06 am
content: Quote from: SeanB on April 15, 2015, 06:18:54 pmWow, I don't think you've ever been able to do that here?

author: FrankBuss
author_rank: Unknown
timestamp: April 16, 2015, 11:37:02 am
content: Quote from: NANDBlog on April 16, 2015, 10:03:19 amThe description in the PDF file linked from the shop says:QuoteSo it comes with a calibration certificat from an accredited laboratory, but you have to ask (and I'm sure it costs more) for calibration by a national standards institute.Quote from: iva on April 16, 2015, 10:20:16 amYes.

author: iva
author_rank: Contributor
timestamp: April 16, 2015, 11:50:17 am
content: Quote from: NANDBlog on April 16, 2015, 11:03:33 amAh.. Ok, I learned *two* things today then, thanks for pointing that out!

author: iva
author_rank: Contributor
timestamp: April 16, 2015, 11:51:41 am
content: Quote from: FrankBuss on April 16, 2015, 11:37:02 amTime to do that first purchase then, thanks for the quick reply!

author: JoeO
author_rank: Frequent Contributor
timestamp: April 16, 2015, 11:59:51 am
content: Quote from: Fungus on April 15, 2015, 09:01:22 pmYou really do not understand the US or know much about the US.Yes, religious people do make policies, like punishing murder.There are little to no educational curricullums decided by Christians in the US.I have never heard about the removal of signs in the grand canyon. Maybe you could supply a link.Are Christians in the US beheading people?Since you are an atheist, please go to the US and declare your atheism in public, then go to a Muslem country and do the same.

author: Howardlong
author_rank: Super Contributor
timestamp: April 16, 2015, 12:05:40 pm
content: Quote from: EEVblog on April 16, 2015, 11:08:06 amRather unbelievable that the Federal Reserve didn't think an offer like that was going to be abused.There are occasional stories of loyalty card "abuses" too. Over here in Blighty a few years ago Tesco, the biggest supermarket chain, did a couple on talcum powder and shampoo. The number of points you could accumulate on the promoted items meant you could accrue enough frequent flyer miles to fly around the world in First and Business class for less than an Economy seat even if you didn't sell your stash of bathroom consumables. People were also ordering pallet loads of these baby and hair products at a discount as many of them were also subject to further discounts like BOGOFs too, and selling them on eBay and at car boot sales, recouping their "investment" and gaining a free vacation to boot.In some ways I take advantage of the situation too, almost all of my purchases for work including production parts are done on my personal Amex card which accrues enough points for some pretty nice vacations for me and the wife. I am not sure, but I believe that in some jurisdictions loyalty or frequent flier points are taxable?

author: Fungus
author_rank: Super Contributor
timestamp: April 16, 2015, 01:27:28 pm
content: Quote from: Howardlong on April 16, 2015, 12:05:40 pmWhy should it bother the Federal Reserve what people do with them?They got coins into circulation didn't they? That's all they wanted.

author: Fungus
author_rank: Super Contributor
timestamp: April 16, 2015, 01:37:02 pm
content: Quote from: JoeO on April 16, 2015, 11:59:51 amAnd, um,quite a lot of other stuff too....Quote from: JoeO on April 16, 2015, 11:59:51 amHah!You got me there!Thanks for the correction.Quote from: JoeO on April 16, 2015, 11:59:51 amNope - despite the Bible ordering them to do so in numerous places, even forvery minor offenses. I hope they can explain that away when they die.Lesson: Basic morality doesn't need a God, it's just common sense.

author: nixfu
author_rank: Unknown
timestamp: April 16, 2015, 01:51:26 pm
content: Quote from: Fungus on April 16, 2015, 01:37:02 pmNot trying to make up excuses for Christians or anything, but even I as a non-christian, DO KNOW that the christian religion could completely eliminate the old testament(Jewish bible), and their actual religious philosophy would change zero.Outside of a few kook sects in america, who have nothing to make themselves different from mainstream Christians other than a wacko literal interpretation of the old testament and which represent a very very tiny number of Christians(even though they seem to get a lot of press attention), the actual Christian religious philosophy is soley based on the tenants taught by and, occurred in the recorded life of the Jesus Christ dude.Anyone who points to the old testament stories and laws of old civilizations recorded in that history as a method to point out flaws in Christianity, just shows their ignorance of said religion, and shows their hand as having an axe to grind and no real substance to their arguments. In my experience, only militant anti-Christians tend to do that, not anyone who has any real idea what they are talking about philosophically.//just saying

author: Fungus
author_rank: Super Contributor
timestamp: April 16, 2015, 03:29:06 pm
content: Quote from: nixfu on April 16, 2015, 01:51:26 pmSure ... apart from the times when it's convenient for them to use the Old Testament to justify their homophobia (or for Invading Iraq, or whatever...)Jesus clearly said the old rules still stand:https://www.biblegateway.com/passage/?search=Matthew+5:17-18If the basic Cristian tenet is to get into heaven then not many of them are going...(and if being nice to other is the only requisite then many Atheists will be taking their places)Quote from: nixfu on April 16, 2015, 01:51:26 pmEither that or pointing out the ignorance of Christians regarding their own religion.Try the Universal Declaration of Human Rights if you want a moral code to live by (and to teach in schools). It beats the Ten Commandments by a long way.

author: SeanB
author_rank: Super Contributor
timestamp: April 16, 2015, 04:38:24 pm
content: Quote from: FrankBuss on April 16, 2015, 11:37:02 amI used to get a calibration done by the local offices of SANAS, but that division got spun off into Trade Metrology, so now I use them to do the 2 yearly certification. I did get to go into the safe where they keep their local reference kilogram, which is the local reference, and which is traceable directly to the standard kilogram held by SANAS in Johannesburg. That in turn travels every few years to Paris first class to get verified against the SI standard unit. You can look, but cannot touch, even with gloves on. Don't breath on it either, the massmeters they use can detect you moving near just by the IR radiation you give off from your face.

author: firewalker
author_rank: Super Contributor
timestamp: April 16, 2015, 06:22:35 pm
content: Quote from: SeanB on April 16, 2015, 04:38:24 pmBolometer!Alexander.

author: SeanB
author_rank: Super Contributor
timestamp: April 16, 2015, 07:04:35 pm
content: Annoying though if you are trying to measure to the milligram level, and the last few digits are moving around with your hand coming near the closed door of the stage though.

author: Fungus
author_rank: Super Contributor
timestamp: April 16, 2015, 07:08:46 pm
content: Quote from: SeanB on April 16, 2015, 07:04:35 pmAren't they lined with tinfoil? I'd put tinfoil on the door if I had one of those.

author: Fungus
author_rank: Super Contributor
timestamp: April 16, 2015, 07:10:37 pm
content: Quote from: SeanB on April 16, 2015, 04:38:24 pmCould they measure the mass of the photons in a camera flash?

author: SeanB
author_rank: Super Contributor
timestamp: April 16, 2015, 07:19:45 pm
content: Probably, but they are a little leery of cameras in there. Seeing as the door is a 30cm thick slab of steel on a set of safe hinges, and the walls, floor and roof are nearly a half meter thick at a minimum, plus they have their own dedicated air handling and fire suppression systems inside along with a metal lined wall I doubt the tinfoil will help in any case. the massmeters sit each on their own solid rock pedestals, set into the floor. Place UUT on them, close door and go to the computer outside and spend an hour waiting for it to settle.

author: Nerull
author_rank: Frequent Contributor
timestamp: April 16, 2015, 08:35:17 pm
content: Quote from: nixfu on April 16, 2015, 01:51:26 pmIt would be a little more reassuring if all of the "tiny minority" who flog the OT were not apparently all elected to congress. Almost no christians follow the OT laws, you're right on that. Many of them have no problem using them to beat others over the head, though. The entire crusade against gays is largely based on Leviticus, a book of laws Christians don't observe.