hybridfree/eevblog-posts huggingface dataset:
Logic level triac switching BT139 - Page 1
Forum section: electronics / general

author: caffeinatedbard
author_rank: Regular Contributor
timestamp: June 02, 2012, 08:58:15 pm
content: Hi all,I am working on a side project and would want to try out the part below. Aside from using an optoisolator and some simpler driver chips that have the zero crossing circuit built in, I have no idea how this part detects zero crossing and how do you trigger the triac on the negative cycle of the AC if it's controlled with 1.5V to trigger the gate? The datasheet claims you can just control it straight from a micro pin... I am very skeptical. Would there be a need for some intermediary hardware between the micro and this part?Any help would be greatly appreciated. If any one knows of any books or app notes that deal directly withlogic leveltriacs, please share them here! I have spent quite some time looking for example appnotes but they all use driver chips that have optoisolation, zero crossing detection and diacs to control the gate leaving the triac very "dumb"if you will.http://www.nxp.com/documents/data_sheet/BT139-600E.pdfCheers,bard

author: codeboy2k
author_rank: Super Contributor
timestamp: June 03, 2012, 06:40:33 am
content: That part doesn't detect zero crossings at all. You are thinking that it is more than it is, but it's still just a TRIAC, and behaves like a TRIAC, it's nothing special.The gate happens to be enhanced to give extra sensitivity, thus it can be triggered with a very low voltage and current. That's what they call "logic level". ugh.I think it's a little reckless for the datasheet to say that it's intended to be directly triggered from a micro-controller without giving an example circuit.Sure itcanbe directly triggered from a microcontroller, but that microcontroller will need to be on the same AC side that you are switching,because the TRIACmustget it's gate current from the MT2 side of the device.If you are using it to switch AC loads, then you should still isolate it from your micro. I suppose , in some embedded applications, beyond human contact,where the micro is directly on the AC mains side, non-isolated, you can directly trigger off a micro I/O pin.Other than that, you will still need an opto-isolator, diac, and optional zero-crossing detector to trigger it.

author: digsys
author_rank: Unknown
timestamp: June 03, 2012, 11:40:44 am
content: Hi, First I'd strongly agree with isolation, for many reasons. There are 2 methods -1st as suggested, using an optocoupler - this requires that you source the gate energy from the AC side.2nd method is to use a tiny pulse transformer and drive it with a pulse train waveform from the micro.You then pick off a tiny amount for the 0-xing detect. The BT139 is a nice TRIAC.
Fabulous YouTube channel for PIC & ASM - Page 1
Forum section: electronics / general

author: iamwhoiam
author_rank: Contributor
timestamp: June 03, 2012, 12:12:20 am
content: This guy really is good, folks - "magidavid". It's rare to see SUCH well thought out, clearly presented videos on PIC ASM:https://www.youtube.com/user/magidavid

author: Joshua
author_rank: Regular Contributor
timestamp: June 03, 2012, 06:22:08 am
content: Thanks! Been lookin for something like this.
Why are the commands in includes in MPASM suite, different to expected? - Page 1
Forum section: electronics / general

author: iamwhoiam
author_rank: Contributor
timestamp: June 03, 2012, 10:55:16 pm
content: Hi folksJust been following a tutorial, and instead of _DATA_CP_OFF, inside "P16F628A.INC" the directive:Code:_DATA_CP_OFFis changed to:Code:DATA_CP_OFFNO leading "_" underscore... :-SAny ideas why?TIA

author: Mechatrommer
author_rank: Super Contributor
timestamp: June 04, 2012, 07:23:42 am
content: Quote from: iamwhoiam on June 03, 2012, 10:55:16 pmno idea! ask the "creator" (or from where you get the file). you edit either your file or the inc to make them compatible, then you good to go. but changing the later is not advisable.

author: oPossum
author_rank: Super Contributor
timestamp: June 04, 2012, 12:36:03 pm
content: The first is typically used with the __config directive for parts with one config word. (most 10F, 12F, & 16F)The second is typically used with the config directive for parts with several config words (18F)

author: codeboy2k
author_rank: Super Contributor
timestamp: June 04, 2012, 08:57:54 pm
content: identifiers that1) begin with a single underscore; or2) contain a double underscore anywhere in the identifierare reserved for the C or C++ implementation and should not be used by authors or library authors.Chances are they wanted the MPASM libraries to be standards compliant.
DMM SparkGap - Page 1
Forum section: electronics / general

author: T4P
author_rank: Super Contributor
timestamp: May 31, 2012, 04:26:44 pm
content: Noticed many even 100$ meters do not have these things ... But the UT61x has a footprint on itHmm.Are they these stuff ?http://sg.element14.com/epcos/b88069x3820s102/gas-discharge-tube-2p-1-3kv/dp/8335354
Teledyne Technologies to Acquire LeCroy Corporation  - Page 1
Forum section: electronics / general

author: Colin
author_rank: Newbie
timestamp: May 31, 2012, 07:59:20 am
content: after Fluke and TEK, Lecroy was acquired. Guys who buy Lecroy stock should be very happy

author: IanB
author_rank: Super Contributor
timestamp: May 31, 2012, 08:08:46 am
content: Old news:https://www.eevblog.com/forum/general-chat/lecroy-has-been-eaten-by-teledyne/
i want one - Page 1
Forum section: electronics / general

author: siliconmix
author_rank: Frequent Contributor
timestamp: June 03, 2012, 09:22:47 pm
content: perhaps a bit smaller though

author: Architect_1077
author_rank: Regular Contributor
timestamp: June 03, 2012, 10:08:03 pm
content: Actually, I want a very big one

author: Mechatrommer
author_rank: Super Contributor
timestamp: June 04, 2012, 07:38:10 am
content: ask madonna to put her butt on. i want more focused one.

author: Stephen Hill
author_rank: Regular Contributor
timestamp: June 04, 2012, 08:04:34 am
content: That man has no respect for headphones...
Led pus out more power than it takes in - Page 1
Forum section: electronics / general

author: Shale
author_rank: Contributor
timestamp: May 30, 2012, 10:48:39 pm
content: http://www.wired.co.uk/news/archive/2012-03/09/230-percent-efficient-leds

author: johnnyfp
author_rank: Frequent Contributor
timestamp: May 30, 2012, 10:52:50 pm
content: Here I am trying to figure out how to heat sink my Power LED's were MIT have brought out an LED that cools itself instead and puts out more light than electrical power going in.This is (no puns intended) so Cool.Jfp.

author: olsenn
author_rank: Frequent Contributor
timestamp: May 30, 2012, 11:05:44 pm
content: Yeah, but your flashlight won't work in the cold

author: IanB
author_rank: Super Contributor
timestamp: May 30, 2012, 11:20:26 pm
content: Let us know what you are going to do with 69 picowatts of light? That would be 69 millionths of a millionth of a watt.

author: elliott
author_rank: Regular Contributor
timestamp: May 31, 2012, 02:28:13 am
content: Quote from: olsenn on May 30, 2012, 11:05:44 pmPut them beside a couple traditional LEDs.
PIC microcontrollers: a very well explained site! - Page 1
Forum section: electronics / general

author: iamwhoiam
author_rank: Contributor
timestamp: May 27, 2012, 10:27:46 pm
content: For those of us struggling with coming to terms with all the intricacies of PIC microcontrollers, here is a site I just found, which is well written and well illustrated:http://www.mikroe.com/eng/chapters/view/2/chapter-1-pic16f887-microcontroller-device-overview/

author: rolycat
author_rank: Super Contributor
timestamp: May 27, 2012, 11:39:40 pm
content: Thanks - it looks like a really good introduction to PIC hardware.It is showing its age a bit in the emphasis on instruction sets and assembly language, and in the chip they have chosen to concentrate on.The PIC16F887 which is referred to as "one of the latest products from Microchip" is at least five years old now, and the PIC18 range and even "16-bit monsters" such as the PIC24 chips offer a cleaner architecture, more features and more memory at what is often a cheaper price these days - and make it easier to use a high level language such as C.

author: Mechatrommer
author_rank: Super Contributor
timestamp: May 28, 2012, 07:18:56 am
content: RAM Memory Banks: BANK0,1 everyone? (no) thanks. i dont know how i'm going to live with pic16 leftover.

author: Galenbo
author_rank: Super Contributor
timestamp: May 31, 2012, 10:07:10 pm
content: I have some of their Boards, program it in C.Completely happy with it.
AMD Launches Piledriver Llano laptops in my town ... - Page 1
Forum section: electronics / general

author: T4P
author_rank: Super Contributor
timestamp: May 30, 2012, 09:32:34 am
content: Been waiting for this one, was quite a surprise when i read about it in their advertisement on the papersYou guys interested?This is the moment i have been waiting for, a integrated graphics solution that finally you can do a hell lot withThis was the video that told me quite a lot about the ... chip
Videos about electronics for scholars  - Page 1
Forum section: electronics / general

author: igorbog
author_rank: Contributor
timestamp: May 29, 2012, 03:13:19 pm
content: HiI need to make a presentation for scholars why to study electronic and vlsi. please, maybe some body know interesting videos from the last years that shows something interesting about electronics(like "from sand to silicon")thanks

author: T4P
author_rank: Super Contributor
timestamp: May 29, 2012, 05:45:59 pm
content: https://www.youtube.com/playlist?list=PL994C8925848790D4&feature=plcpOld but goldie.Or you can also go technical and talk about it yourself
South Africa and Australia share SKA  - Page 1
Forum section: electronics / general

author: Bloch
author_rank: Unknown
timestamp: May 29, 2012, 03:13:45 pm
content: Greate news for Dave. In one of theamphour podcast you was mad/disappointed that Australia did miss out on the SKA.http://www.astronomynow.com/news/n1205/27ska/Quote

author: SeanB
author_rank: Super Contributor
timestamp: May 29, 2012, 04:04:19 pm
content: Actually it is spread over 4 countries and 2 continents...........

author: AntiProtonBoy
author_rank: Frequent Contributor
timestamp: May 29, 2012, 04:17:11 pm
content: QuoteSounds exciting! Will be very interesting what info the scientific community will get out of that.

author: Mechatrommer
author_rank: Super Contributor
timestamp: May 29, 2012, 05:05:51 pm
content: Quote from: AntiProtonBoy on May 29, 2012, 04:17:11 pmnot god. opps! did i mention g.o.d? wrong thread!
old high voltage test gear - Page 1
Forum section: electronics / general

author: siliconmix
author_rank: Frequent Contributor
timestamp: May 29, 2012, 09:30:33 pm
content: http://www.museumoftechnology.org.uk/expand.php?key=970nice.

author: Dawn
author_rank: Regular Contributor
timestamp: May 29, 2012, 10:22:05 pm
content: The 500 series Tek in the collection just made me feel ancient and obsolete too!Thanks for posting.

author: bullet308
author_rank: Frequent Contributor
timestamp: May 30, 2012, 12:00:35 am
content: Love the old UK military and civil defense rad gear on that page. You don't see much of that on this side of the pond. Those Russian dosimeter pens go up to 500 R/h. Half-scale, your sick, full-scale, your dead. Ah, the romance of the Cold War...

author: siliconmix
author_rank: Frequent Contributor
timestamp: May 30, 2012, 07:15:41 pm
content: i love the simplicity of that hv voltmeter.no fried pcb tracks with that

author: T4P
author_rank: Super Contributor
timestamp: May 31, 2012, 03:26:59 pm
content: Quote from: siliconmix on May 30, 2012, 07:15:41 pmCertainly yes. Where did you get your forum picture? It's lovely

author: siliconmix
author_rank: Frequent Contributor
timestamp: May 31, 2012, 03:36:43 pm
content: http://steve.cooleysekula.net/blog/2011/08/21/the-greenhouse-effect-part-3-gas-amplifier/
Reasonably priced CR2032 cells in Australia? - Page 1
Forum section: electronics / general

author: JamesAus
author_rank: Contributor
timestamp: May 29, 2012, 01:16:08 pm
content: Hi allHopefully this isn't too "off topic"...Just wondering if anyone knows of a local (Australian) source for decent quality CR2032 lithium cells at a reasonable price in quantities of 200 - 1000 pcs. When I say reasonable price I'm thinking sub 50c/cell.Digikey has quality cells for a fraction of the price of anything I can find locally but of course shipping is a major issue. I've had to forfeit hundreds of cells at FedEx previously because of vague or misunderstood shipping / packaging guidelines for lithium cells. They make it to Australia Ok but can't be shipped further on domestic air services and trying to redirect via road once in the country adds time, expense and headaches.Ebay brings up plenty of matches but either they are not in Aus, are chinese "yum cha" brand or are likely "yum cha" repackaged as a quality cell.Thanks in advance,James
3D printing with an industrial strength handheld plastic extruder - Page 1
Forum section: electronics / general

author: Pat Pending
author_rank: Regular Contributor
timestamp: May 28, 2012, 10:37:50 pm
content: Fancy some 3D printing?Where here's the business end of a handheld plastic extruder for some freestyle 3D printingfromhttp://www.leister.ca/Makerbot, RepRap, Sumbot and Printrbot, etc. had better watch out!
World War Z has begun!!! - Page 1
Forum section: electronics / general

author: Hypernova
author_rank: Unknown
timestamp: May 27, 2012, 09:39:52 am
content: Naked man killed by Police near MacArthur Causeway was ‘eating’ face off victimhttp://www.miamiherald.com/2012/05/26/2818832/naked-man-shot-killed-on-macarthur.htmlQuoteIf you got a shotgun now is the time to stock up on shells.

author: bullet308
author_rank: Frequent Contributor
timestamp: May 27, 2012, 12:18:07 pm
content: I guess he was hungry or something.

author: SeanB
author_rank: Super Contributor
timestamp: May 27, 2012, 12:21:31 pm
content: Stopped taking his Thorazine and lithium.............

author: olsenn
author_rank: Frequent Contributor
timestamp: May 27, 2012, 12:33:41 pm
content: Quote...More like PCP and the T-Virus

author: bullet308
author_rank: Frequent Contributor
timestamp: May 27, 2012, 12:44:18 pm
content: Those must have been some awfully powerful antipsychotics he was not taking....BTW, thorazine and lithium are pretty much obsolete now.

author: SeanB
author_rank: Super Contributor
timestamp: May 27, 2012, 12:48:36 pm
content: Out of patent, available as a cheap generic, so very much a part of state hospitals here. Of course you could find they had run out, or the stock was " missing" and then you would get the next thing on the shelf, generic paracetamol that may or may not be counterfeit.

author: Mechatrommer
author_rank: Super Contributor
timestamp: May 27, 2012, 08:20:04 pm
content: Quote from: olsenn on May 27, 2012, 12:33:41 pmyea yea, we are doomed. where's milla jovovich?

author: SeanB
author_rank: Super Contributor
timestamp: May 27, 2012, 08:30:13 pm
content: She's all wrapped up with being Residentially evil....

author: bullet308
author_rank: Frequent Contributor
timestamp: May 27, 2012, 10:03:43 pm
content: I understand that they are cheap and widely available, and that they are a damn-site better than nothing. However, the side effects can be pretty terrible....

author: G7PSK
author_rank: Super Contributor
timestamp: May 28, 2012, 09:15:48 pm
content: This is what happens when Hollywood keeps churning out zombie and vampire trash movies, it eventually warps the minds of some people who are susceptible to suggestion or are a few bricks short of a load.

author: nanofrog
author_rank: Super Contributor
timestamp: May 28, 2012, 10:50:02 pm
content: Quote from: G7PSK on May 28, 2012, 09:15:48 pmBlame Hollywood?The funding cuts to mental health providers would make more sense IMHO.

author: Hypernova
author_rank: Unknown
timestamp: May 29, 2012, 01:13:53 am
content: Next thing you know someone's gonna start blaming it all on video games! Will someone think of the children!!!

author: sonicj
author_rank: Frequent Contributor
timestamp: May 29, 2012, 02:07:26 am
content: I'd bet he was on "Bath Salts." Here's two newsworthy incidents that occurred in my hometown...QuoteFlorida Bans Cocaine-Like 'Bath Salts' Sold In Stores@ NPRQuoteFlorida bans 'bath salt' drugs after violent outbursts@ Sun Sentinel*edit* Forgot about this one... This dude got naked, flipped out and destroyed the neighborhood.Naked Rampage Blamed on "Bath Salts"
Cool HP find on ebay - Page 1
Forum section: electronics / general

author: reagle
author_rank: Unknown
timestamp: May 28, 2012, 03:44:16 am
content: http://www.ebay.com/itm/HP-Agilent-VHF-Oscillator-Model-HP3200A-Clean-Checked-NO-RESERVE-/160804165809?pt=BI_Signal_Sources&hash=item2570acd8b1#ht_600wt_1392HP/Agilent VHF Oscillator Model HP3200A,Tubes, gears, handtraced boards. Looks like a good teardown target?
modifications to Daisy MP3 player, need help please ! - Page 1
Forum section: electronics / general

author: dirkrenders
author_rank: Newbie
timestamp: May 28, 2012, 04:45:17 pm
content: Hi,I've made a number of Daisy MP3 players for a project, working justfine ...http://www.teuthis.com/daisy/index.htmlThe question now is to make a few changes to the design to make itmore suited for a new application.1. letting it use SD/HC also instead of now only SD (as the regular SDcards become more and more difficult to buy)2. adding (or programming) something in it to make it stop workingafter a periode of time (e.g. 1 year), unless a new music collectionis placed into it (with the MP3's having some sort of unlocking codein their tag or something ?).Could/would somebody help me with this please ?Greetings

author: T4P
author_rank: Super Contributor
timestamp: May 28, 2012, 05:21:31 pm
content: SDHC requires better hardware most of the time and a new SD library i think

author: PA0PBZ
author_rank: Super Contributor
timestamp: May 28, 2012, 08:12:44 pm
content: I don't think the hardware has to be changed, both the standard SD cards and the newer HC ones have the same interface but there is one big difference: where with normal SD cards you address a byte, in the HC ones you address a sector with multiple bytes.I had a look at the source code and unfortunately they don't use a libary but it is all written out in the code, so you'll have to write a lot of code to be able to use the SD/HC cards.
Media Request from The Age - Online MIT Courses - Page 1
Forum section: electronics / general

author: EEVblog
author_rank: Unknown
timestamp: May 28, 2012, 02:53:26 am
content: I've been contacted by a writer from The Age (an Oz newspaper) who is doing a story on online education, and would like to interview some people about their experiences with such courses. e.g. the recent MIT course, or the likes ofhttps://www.coursera.org/She has seen the various forum threads on the MIT course and is very interested in interviewing people who have done it.If interested, contact me and I'll pass on details.Dave.
Circuit noise...how? - Page 1
Forum section: electronics / general

author: HooRide
author_rank: Regular Contributor
timestamp: May 26, 2012, 10:26:35 pm
content: I noticed today that my network switch (Netgear SG108) is making a kind of audible 'digital noise' when there is network traffic going through it. I've noticed a graphics card and computer memory do the same in the past. Also, my first Agilent MSO-X 3014A made some weird noise when it was powered on (before I sent it back to have it replaced). I am positive this is not fan noise (like Agilent insisted it was).What causes circuits to make noise? Maybe a coil/transformer/inductor vibrating?

author: Psi
author_rank: Super Contributor
timestamp: May 26, 2012, 10:59:02 pm
content: It's the inductor in the switchmode powersupply.Sometimes they vibrate in a way that produces sound in the audible range.It can be a sign of failing capacitors in the powersupply, so if i notice a device making that high pitched sound and it never used to, i always take it apart and check for bulging electrolytic caps.

author: TriodeTiger
author_rank: Regular Contributor
timestamp: May 27, 2012, 12:14:08 am
content: Quote from: HooRide on May 26, 2012, 10:26:35 pmWrapping a wire around a toroidal core and passing a 1kHz square wave will almost certainly emit a buzz, you can even make a speaker, in fact.. isn't that how speakers work?Loose windings in the transformers/inductors something else, however tightly wound and even glued down inductors are harder to get loose. If you can find out what the problem is it's invaluable experience.

author: Pentium100
author_rank: Frequent Contributor
timestamp: May 27, 2012, 01:58:39 am
content: Even if the windings are not loose, the transformer can vibrate because of magnetostriction (ferromagnetic material in a magnetic field can change its length).And speakers are made with straight coils, not toroidal.

author: Skibane
author_rank: Contributor
timestamp: May 27, 2012, 05:00:50 am
content: Quote from: HooRide on May 26, 2012, 10:26:35 pmThe presence of network traffic probably consumes more current from the power supply than the absence of traffic.Changes in power supply current can cause inductor and transformer cores and windings to move a tiny bit - much like the position of a speaker voice coil moves as the current flowing through it varies.If these changes are occurring at audible frequencies (or even at some harmonic of audible frequencies), you may be able to hear them.
Forum request - Page 1
Forum section: electronics / general

author: IanB
author_rank: Super Contributor
timestamp: May 26, 2012, 02:20:31 am
content: Hi Dave,When I browse the forum I keep getting this pop-up on every page refresh. Is there a forum setting you can toggle to turn it off? It seems to be a bit of a software design fail as it apparently wants to keep nagging you until you give in and click the OK button.

author: PeterG
author_rank: Frequent Contributor
timestamp: May 26, 2012, 03:19:50 am
content: I have to admit, it is a most annoying "Feature" .......Regards

author: EEVblog
author_rank: Unknown
timestamp: May 26, 2012, 03:23:13 am
content: Hmm, that's strange.I don't recall using any sort of Plugin on the forum for tapatalk, and on a quick glance cannot find anything.So maybe it's not the forum software doing this, but something on your phone or provider is doing maybe?Like it knows it's a forum, and knows about tapatalk, and pops up?Anyone else?Tapatalk is usually a better way to browse the forum on a phone anyway, have you tried it?i don't see it on my android using Opera broswerDave.

author: IanB
author_rank: Super Contributor
timestamp: May 26, 2012, 03:27:34 am
content: I did buy and install Tapatalk actually, but I tried it and didn't like it. It seemed horribly unintuitive to use. But I might give it a second chance since you are right, the web is not brilliant for forum browsing on a phone either.

author: EEVblog
author_rank: Unknown
timestamp: May 26, 2012, 03:29:05 am
content: Actually, yes I did install a Tapatalk plugin on the forum, but I cannot find any settings for it.Dave.

author: Barryg41
author_rank: Contributor
timestamp: May 26, 2012, 04:08:10 am
content: I use tapatalk on my Ipad for three other forums, but not for EEVBLOG. It asked me the first time, I click cancel, it has never asked me again. If you surf in private mode it might ask you each and every time.

author: joelby
author_rank: Frequent Contributor
timestamp: May 26, 2012, 04:45:07 am
content: I guess it's good advertising because I got annoyed with the pop-up and bought the app. It's much more useable than the Web site on a phone, but I do find that it has problems when you try to load more unread topics - you end up with the same topics repeated several times (e.g. topics 1-30 will display, then you load more and get 1-30, 1-30, 31-40). Haven't been bothered to figure out exactly why this is happening and report it to Tapatalk.Anyway, Dave, you could disable the popup by removing the script from the site:<script type="text/javascript" language="JavaScript" src="https://www.eevblog.com/forum/mobiquo/tapatalkdetect.js"></script>It's probably less intrusive to have a "Also available on Tapatalk" link than the popup (especially since there isn't a free Tapatalk option), though it's true that it shouldn't pop up every time unless you're deleting cookies.
WIN an Agilent U1732B LCR Meter : Discussion Thread. - Page 1
Forum section: electronics / general

author: HackedFridgeMagnet
author_rank: Super Contributor
timestamp: May 26, 2012, 12:04:34 am
content: I thought if people wanted to discuss aspects of the WIN an Agilent U1732B LCR Meter contest they could do so in this thread, so they didn't muck up the EEVblog wobulator program.My thoughts is Dave going to explain more about the wobulator program, so people could discuss the technical merits.

author: baljemmett
author_rank: Unknown
timestamp: May 26, 2012, 12:13:50 am
content: I think he explained a bit about it inthe draw videofor the previous (first!) contest, if that helps! (I can't watch it at the moment, unfortunately, or I'd double-check before posting...)

author: EEVblog
author_rank: Unknown
timestamp: May 26, 2012, 01:03:20 am
content: Yes, explained in the first contest, and I think I even posted the source code on here somewhere...Dave.
PIC32 ethernet examples... - Page 1
Forum section: electronics / general

author: LuckyJaker
author_rank: Contributor
timestamp: May 25, 2012, 02:03:14 pm
content: Am I the only open having trouble with the Microchip PIC32 ethernet libraries and example code... ?, I have been programming micro controllers for the last 35 years, and recently started programming the PIC32 and I can say that the ethernet example code and libraries are not very user friendly...!

author: Ed.Kloonk
author_rank: Super Contributor
timestamp: May 25, 2012, 03:03:05 pm
content: Nar mate. I'll trade you a arduino SD card reader routine that is truly shocking.Seriously, if you post some code and your dilemma, there are some folks here who may be able to help you.

author: LuckyJaker
author_rank: Contributor
timestamp: May 25, 2012, 03:28:45 pm
content: My problem is simple, I have designed and programmed a full DMX light controller and high power LED lamps for stadiums, I implemented the controller with ethernet as an option, when I use the examples from the beta of the PIC 32 version 6 library, and adapted the code for my I/os the darn thing won't even start... ( I will debug further and give you guys more info )
Random anecdote.  - Page 1
Forum section: electronics / general

author: Ed.Kloonk
author_rank: Super Contributor
timestamp: May 25, 2012, 12:20:14 pm
content: I was invited to do a day's maintenance on a stud farm twenty years ago. One of the jobs was to install automatic water-ers for the horses. My job was to mount the things on the fence posts ahead of the irrigation bloke who apparently was incapable of installing the actual feeder. I now know why.One of the paddocks in which be had to work in was home to a prized stallion. Now this horse was a frisky bugger. When a lady horse was delivered for his pleasure via horse float, the randy fella would start going berserk and would nearly kick down his stable. Never seen any thing like it, although I could sympathise with his predicament.Anyhoo. A horse handler (who could well have been a lumber-jack) had to mind this damn horse while we attended to the job of fitting the water feeder. The first thing I noticed was an electric fence attached to the fence so I thought it would be prudent to let the apprentice work the inside of the paddock and I would be on the road side, with the shifter holding the bolts while the apprentice tightened up the nuts.Next thing I know I'm jumping involuntarily all over the place trying to hold the shifter on the bolt. Bloody apprentice was touching the wire with his forearm and because he was wearing nice new work boots, the jolt went right though him, the bolt and then to the silly bastard on the other side holding the shifter.

author: obiwanjacobi
author_rank: Super Contributor
timestamp: May 25, 2012, 02:31:43 pm
content: At my first job I revamped an old Whurlitzer cigarette machine for a customer.We (me and a colleague) took out the mechanical stepper that kept track of the money inserted and some other relays-stuff we didn't need and replaced it with a Motorola 68HC based solution. I wrote the entire program in assembler (all 4k's of it ;-) and it had an electronic coin tester and a LCD display. After we combated the spikes the other relays in the machine produced, it worked flawlessly and the customer was able to use these machines for many years to come. I think we did about 50 for him eventually - which was, after the rush of creativity of designing it, a bit of a bore...That was my first real project with an MCU.

author: Ed.Kloonk
author_rank: Super Contributor
timestamp: May 25, 2012, 02:37:06 pm
content: I wonder what became of it?And smoking as good as banned in the lowlands now isn't it?
My new 2215 [some pics!] - Page 1
Forum section: electronics / general

author: TriodeTiger
author_rank: Regular Contributor
timestamp: May 19, 2012, 08:27:50 am
content: I thought I'd take a few and post them, as I probably cannot review it nor make a teardown for a little while.Webcam came out fairly well actually (misplaced camera.) Forgot to mention, got for $80 or so on eBay, + $80 shipping.The only text on my desk that I drool at constantly, no other.Here's the triggered delay sweep! I felt like a genius deciphering how to use it:1.6MHz or so hacked up square wave, top displaying 200nS/div, bottom is 50nS portion (can 10x zoom to 5nS it says)Two pornographic knobs that are fun to use when alone in the room:The bottom B time delay position knob turns from 0 -> 0.9, and after that goes back to zero incrementing the back knob automatically. It's like turning second hands on a clock, and the knob feels like it is mounted on soft air (ball bearing?)And just a general front shot I thought would complete it:Really messed up superimposed waveform, I know.Only thing wrong is B trigger level knob is missing (it's a blue base if visible in pictures), could not care less, in fact I like it.The variable holdoff is the only knob that seems a little craggy turning, it is at the top so maybe it got bashed a little during transport. Turning it a few times cleared the grit under it and it is fine.

author: w2aew
author_rank: Super Contributor
timestamp: May 19, 2012, 06:05:47 pm
content: Congratulations on the new (old) scope!

author: LuckyJaker
author_rank: Contributor
timestamp: May 25, 2012, 01:55:01 pm
content: I got my new Agilent 2024X last month I love it !

author: obiwanjacobi
author_rank: Super Contributor
timestamp: May 25, 2012, 02:22:43 pm
content: I recently bought a Dynatec 8020 - 20 Mhz for 50 euros.I had a second hand Voltcraft DSO-220 (USB) and that just wasn't doing it for me.Happy camper.
Energy Saving Plug, Plug it in And Enjoy The Savings...... - Page 1
Forum section: electronics / general

author: Sionyn
author_rank: Frequent Contributor
timestamp: May 23, 2012, 02:12:51 pm
content: new candidate for BOWhere's the SepalThe Energy Wizard saves you over £60 per year. This is based on 10% Electricty Saving with an average annual UK electricity bill of £600.This brand new Ecotek Energy Wizard is used to help reduce your electricity consumption and improve the efficiency of various appliances and circuits for the home and industry. Energy Wizard is easy to use; you just simply plug-in to any socket and start making continuous savings.The Energy Wizard plug works by optimizing the voltage and current demands by using a combination of filtration and correction techniques, as a result reducing your electricity consumption and achieving over 10% savings off your electricity bill guaranteed. These savings have been verified by an Independent Regulatory Compliance Laboratory and results showed that when the Energy Wizard was used 12.6% was saved in energy consumption.and some nobber selling themhttp://www.ebay.co.uk/itm/NEW-Ecotek-energy-saver-wizard-plug-save-electricity-/260969598777?pt=UK_Sound_Vision_Other&hash=item3cc3000f39

author: T4P
author_rank: Super Contributor
timestamp: May 23, 2012, 02:25:09 pm
content: Ya right, not this bovine byproduct again.

author: sonicj
author_rank: Frequent Contributor
timestamp: May 23, 2012, 02:30:54 pm
content: Thats incredible!I watched a youtube review the other day where the guy plugged one of these in and his CFL consumed an extra watt. LOL!-sj

author: M. András
author_rank: Super Contributor
timestamp: May 23, 2012, 02:45:40 pm
content: Quote from: sonicj on May 23, 2012, 02:30:54 pmhmm nice power saving

author: sonicj
author_rank: Frequent Contributor
timestamp: May 23, 2012, 03:02:09 pm
content: Quote from: M. András on May 23, 2012, 02:45:40 pmIndeed!Here we go, I found the video... CFL starts at approx 5:00

author: siliconmix
author_rank: Frequent Contributor
timestamp: May 24, 2012, 12:29:30 am
content: Quote from: Sionyn on May 23, 2012, 02:12:51 pmhes says on the ebay page."i have a joblot of these" .i bet he has. meh

author: codeboy2k
author_rank: Super Contributor
timestamp: May 24, 2012, 06:11:59 am
content: related..http://www.bigclive.com/power.htm

author: Cybeonix
author_rank: Newbie
timestamp: May 25, 2012, 03:17:01 am
content: Looks pretty dodgy to me
High Speed Digital CMOS & Mixed Signal Lectures - Page 1
Forum section: electronics / general

author: elmohandis
author_rank: Contributor
timestamp: May 24, 2012, 01:22:56 pm
content: Hello!I have been a long time follower of the blog, but newly entered the forum!I would like to share a set of lectures by a really great engineer, Dr. Stefan Henzler. He works for Infineon and teaches at theTechnical University of Munich (TUM).He gives two really important courses there. BEST THING is that the courses are recorded with his pen input sync'ed to his voice. It is quite similar to a classroom experience!First is regarding High Speed Digital CMOS design: (Inverters, buffers, types of flip flops, clocking and clock trees, PLL's , and a great section on Arithmetic circuits: different types of adders and multipliers (most basic to advanced).Link:http://www.lte.ei.tum.de/lehre/EDHCS/2011/EDHCS_en.htmlSecond course is regarding Mixed Signal Electronics ( Sample and hold circuits, Switched capacitor circuits, different types of ADC's , DAC's , and Sigma-Delta converters as well.) The parts of ADC's and DAC's are really worthwhile for any designer to know.Link:http://www.lte.ei.tum.de/lehre/gist/gist2011/index_en.htmlIf you do not want to download the MP4 version and want to view the videos using the "video" hyperlink, please use IE (i know ....) since the plugin used is not so happy with Firefox & Chrome.Hope they are useful to at least one of you out there! I actually took these courses and benefited a great deal. I am happy to have any discussions regarding the content since I guess it is still fresh from last year.Enjoy!!

author: rbola35618
author_rank: Frequent Contributor
timestamp: May 25, 2012, 01:32:40 am
content: Thanks for the posting. Looks like very good material. I've already bookmarked it.Robert
Audiophoolery - Page 1
Forum section: electronics / general

author: Write_to_Smokegenerator
author_rank: Regular Contributor
timestamp: May 22, 2012, 10:48:41 am
content: Certainly not what I expected, but it was fun to watch.

author: deephaven
author_rank: Frequent Contributor
timestamp: May 22, 2012, 12:29:08 pm
content: What an irritating twit!

author: Psi
author_rank: Super Contributor
timestamp: May 22, 2012, 12:50:03 pm
content: His voice reminds me of the guy that does Zero Punctuation.Quite an entertaining review.Sorry deephaven, i don't find him irritating or a twat at all

author: TriodeTiger
author_rank: Regular Contributor
timestamp: May 22, 2012, 09:05:25 pm
content: "And I said to him: Would you pay £200 for these?"

author: elmohandis
author_rank: Contributor
timestamp: May 24, 2012, 12:58:42 pm
content: Remember: The more expensive it is, the better it MUST be!

author: jsoderquist
author_rank: Contributor
timestamp: May 24, 2012, 01:09:27 pm
content: Smoke and mirrors.

author: VintageHenk
author_rank: Contributor
timestamp: May 24, 2012, 02:17:42 pm
content: Hahaha, that was quite an entertaining review.

author: Cybeonix
author_rank: Newbie
timestamp: May 24, 2012, 07:26:03 pm
content: Fun video, I enjoyed it
Can you help optimize this design - Page 1
Forum section: electronics / general

author: bobhaha
author_rank: Contributor
timestamp: May 21, 2012, 05:50:49 am
content: Hey guys,Would you be so kind as to optimize this design. In theory it should be working, but I need your thoughts and opinions before I make the prototype boards.... does anything stand out that needs changing or that can be changed out for a cheaper alternative.This is going to be a constant current driver that needs very smooth output noise. It will be running a range of laser diodes and must be current adjustable (by changing the resistors).PS: The trimmer will be going.... because people have said that creates noise on the output... is that true?Thank you for your time-Adrian

author: free_electron
author_rank: Super Contributor
timestamp: May 21, 2012, 06:38:23 am
content: Whats the zener for ?That tps chip cannot produce more than 7 volts on its output.... If you try to go above that you will fry it ..Another problem is that the regulator.only gets feeback when the opamp Lt6106 is powered. This is going to do funny thing when it is powering up... You would almost have to power the lt chip from a separate supply...Try it. Maybe it works, maybe not... Hard to say

author: bobhaha
author_rank: Contributor
timestamp: May 22, 2012, 05:41:52 am
content: If you don't have a load (the laser diode), the driver has a zero voltage feedback and increases the output voltage until output capacitor make a loud boom!!! The zener diode solves this problem; when the sum of output voltage+0.5Volt nominal feedback is more than Vz, in the zener diode starts to flow current, the feedback becomes again effective and the output voltage is limited.As far as I understand. Please correct me if I'm wrong.

author: Gall
author_rank: Frequent Contributor
timestamp: May 22, 2012, 01:01:44 pm
content: Oh, this one? I worked with very similar circuit about a year ago.A digital potentiometer or a DAC may be used for the trimmer. A MCU is necessary in this case.It turned out that TPS63020 may oscillate very very easily. Be very careful calculating the feedback loop, especially C7 and C8 values. Since TPS63020 has quite high gain and C4+C5 combined with TPS's internal resistance give some phase shift, additional phase shift in R3+C6, then C7+C8, you may end up with some kind of oscillator similar to this:http://freecircuitdiagram.com/wp-content/uploads/2009/04/sine-wave-oscillator-phase-shift.gif

author: bobhaha
author_rank: Contributor
timestamp: May 22, 2012, 05:04:40 pm
content: A trimmer is not needed. I am going with a set resistor instead.What are your thoughts on the schematic?

author: Gall
author_rank: Frequent Contributor
timestamp: May 24, 2012, 09:32:50 am
content: It should work - theorethically. But I didn't check the values of components, especially capacitors. You may look at the diagrams in datasheet to determine the effective gain of TPS and then do a Bode plot of the feedback circuit. And check it with oscilloscope using a broken laser diode or a bunch of LEDs for a dummy load.
I'm such a dumb-donkey! - Page 1
Forum section: electronics / general

author: pullin-gs
author_rank: Regular Contributor
timestamp: May 23, 2012, 02:14:53 pm
content: ....I let the magic smoke out of my favorite 3S lithium pack!I left my pack hooked up to my wireless bridge (I access my lab Oscope via WIFI).By the time I realized the errors of my ways, one of the cells had depleted down to almost zero-volts.So I now have a 2S pack and a 1S silver puff-ball.I've killed several packs over the years by forgetting to disconnect them.Future project: Compact 1-hour "auto-cutoff" circuit which cuts off power from pack.Or better yet, a low- voltage (sensor for each cell) "auto-cutoff" circuit....you know those $3 low-voltage LIPO low-voltage warning alarms? Using one of those would make for a very fast turnaround for this project.

author: IanB
author_rank: Super Contributor
timestamp: May 23, 2012, 02:23:27 pm
content: I dismantled a laptop battery pack yesterday to harvest the cells. I was disappointed to find that all the cells were reading about 40 mV. Not sure why; either it had been sitting unused for months, or the parasitic drain from the PCB had discharged them. So I got 8 paperweights

author: sonicj
author_rank: Frequent Contributor
timestamp: May 23, 2012, 02:36:10 pm
content: If this just happened, I would try charging it back up! (in a lipo sack of course)-sj

author: pullin-gs
author_rank: Regular Contributor
timestamp: May 23, 2012, 02:53:19 pm
content: Quote from: sonicj on May 23, 2012, 02:36:10 pmI had it on a charger (at 1/2C) within minutes. It charged back up to 4.2V. The problem is it only took about 10 minutes.This worked out to about 1/10th of the original capacity.The other two cells took a full charge.I have a battery vault that I store and charge in.It is a heavy two-drawer filing cabinet (locking of course), vented to the outside.Two drawers.....one for charging and charger storage, and one to store all packs, some are put inside a vented fire safe (unlocked) that I keep in the drawer.Having seen a few LIPO fires/explosions firsthand, I believe that even these precautions may not be enough.A cellphone is around a 1S 800 Mah pack. My largest pack is a 6S 5Ah pack.

author: sonicj
author_rank: Frequent Contributor
timestamp: May 23, 2012, 03:13:32 pm
content: Hmm... thats weird. My FMA has a lipo recovery mode, but im not sure how it works... I think its a uber slow charge.You're setup sounds safer than mine. I charge in a sack and store in a ammo can. (most of the time) The filing cabinet is a nice idea!-sj
Need an SMS to parallel printer driver - any thoughts? - Page 1
Forum section: electronics / general

author: iamwhoiam
author_rank: Contributor
timestamp: May 23, 2012, 12:09:31 am
content: Need an SMS to parallel printer driver - any thoughts?I have myriad old mobile phones and a very very old, sturdy ICL Microline 83A printer which works superbly. I want to send an SMS to a phone, and have it print out on the dot matrix printer. I do NOT want to involve PCs whatsoever, and need to make this as simple as can be.Do any of you have any simple suggestions? Thank you

author: baljemmett
author_rank: Unknown
timestamp: May 23, 2012, 12:24:52 am
content: Quote from: iamwhoiam on May 23, 2012, 12:09:31 amA lot of phones support AT commands to query the SMS inbox; afraid I don't have any references to hand and would rather go to bed than Google them just now, but you should be able to turn something up pretty easily (I think AT+CGMR rings a bell). I would imagine a small microcontroller would be able to do the job for you nicely; sit polling the phone for new messages and squirting them out to the printer as required.Having built a RS232-to-parallel converter around a PIC16F689 before, I'd probably just advise making sure the phone you choose supports hardware handshaking on the serial port so you can tell it to hold fire when the printer asserts the BUSY line. Apart from that it should be pretty straightforward!

author: Psi
author_rank: Super Contributor
timestamp: May 23, 2012, 12:32:59 am
content: What you want is an old Nokia with F-Bus (M-Bus may work too)1) Wire up a avr/pic UART (with some 5v-3.3v uart leveling) to the nokia bus pins. (you will need a crystal on the micro, internal osc wont be fast/stable enough for 115200 baud)2) Configure the micro UART to the baudrate for the bus type used. F-bus is 115,200bps, 8 data bits, no parity, one stop bit3) Send a string of 0x55 ('U') 128 times (this syncs the nokia to the 115,200 baud clock)4) When the phone receives a sms it automatically sends the data out the bus. So all you need to do is unpack the 7bit text into 8 bit ascii.This website has all the nokia bus info and shows which gold pads are the bus lineshttp://www.embedtronics.com/nokia/fbus.htmlI'm not too sure how dotmatrix printer coms work, but if they just print raw 8bit data you might be able to do away with the microcontroller if you can build a 7bit to 8bit unpacker using logic gates.Then let the phone send the entire sms frame through some unpacking logic to the printer itself. You'd get some formatting data, the phone number and the message.
Why Agilent U1253B cost more than U1273A? - Page 1
Forum section: electronics / general

author: zaoka
author_rank: Frequent Contributor
timestamp: May 21, 2012, 09:09:59 pm
content: Why Agilent U1253B cost more than U1273A?I was always thinking that U1272/3 is new and better meter.... ??

author: nanofrog
author_rank: Super Contributor
timestamp: May 21, 2012, 09:37:21 pm
content: The higher numbers don't always mean better when comparing a different series to another, as they may be made for different uses (for example, the U127x is geared more for industrial plant work, while the U125x is targeted primarily at electronics).Take a look at the specs/features (IIRC, they have a compare function on Agilent's site), and you'll see how/where they differ and why the U1253B is more expensive (tighter specs if you need them).

author: T4P
author_rank: Super Contributor
timestamp: May 22, 2012, 06:17:51 pm
content: Plenty of reasons why, U1253 is much more accurate and is targeted at for electronics use, and it doesn't only have 30,000 it has 50,000 counts
nice idea robotic fish - Page 1
Forum section: electronics / general

author: siliconmix
author_rank: Frequent Contributor
timestamp: May 22, 2012, 09:46:10 am
content: http://www.bbc.co.uk/news/science-environment-18124372lets hope a shark dont take a fancy to it.

author: Rerouter
author_rank: Super Contributor
timestamp: May 22, 2012, 09:53:54 am
content: it seemed like it was only made for surface skimming from the video, which leads me to the more important thought, how many drunks are going to ram into/ over them in there boats, because it seems like a good idea at the time,really these things would want to cruise a few feet below the surface to avoid boats :/