hybridfree/eevblog-posts huggingface dataset:
Sealed Lead Acid Battery Short - Page 1
Forum section: electronics / general

author: minibutmany
author_rank: Regular Contributor
timestamp: March 24, 2013, 10:57:04 pm
content: Today we had a bit of a scare with a sealed lead acid battery as the leads being used to connect it to the circuit we were testing shorted out. There was a ton of smoke but we were able to disconnect it fairly quickly before anything insane happened. The leads are now completely melted through. My question was on if this battery is at all usable now. I tested it and it is surprisingly still at nominal voltage. The seal seems to be broken so I thought it might not be safe to run indoors.Thanks,Kelly

author: houdini
author_rank: Regular Contributor
timestamp: March 25, 2013, 01:09:31 am
content: yes it most likely fine.

author: A Hellene
author_rank: Frequent Contributor
timestamp: March 25, 2013, 02:34:10 am
content: If the battery vent seals are broken, this is a result of pressurised gas («???»* in Greek, i.e. oxygen and hydrogen in perfect burning analogies, which explodes violently when ignited) escaping the battery compartments. This usually happens during overcharging, and the vent valves protect against explosion from the gaseous pressure being built within the sealed battery compartment.In your case, I think that the extended short circuit overheated the plates, resulting in the vaporisation of some of the electrolyte and the permanent destruction of a part the battery plates coating material.Anyway, if the electrolyte has lost water (in the form of escaped gasses) the battery needs to be replaced because the electrolyte acid concentration is not right anymore, directly affecting the battery capacity and life.-George[ * ] Transliterated: "crotoun aerio" (since the forum software database does not seem to support Greek characters...)

author: G7PSK
author_rank: Super Contributor
timestamp: March 25, 2013, 12:35:18 pm
content: What size was battery and what size were the leads as it is more than likely that with a large battery and not to big leads that the battery did not even grunt in order to burn the leads out.

author: Unknown
author_rank: Unknown
timestamp: March 25, 2013, 01:34:08 pm
content: The vent seal has poped due the short terminals, however brief the short, gasing has occured...if the the battery takes a re-charge ! and not showing a high current reading at the start, then it has survivedthe short. However, if the charge current starts high and shows no sign of reducing within 10 minuits of charging,then the damage has been done, and the plates are damaged... that being the case, replace the battery.

author: knarf.be
author_rank: Contributor
timestamp: March 27, 2013, 12:52:11 pm
content: Quote from: vlf3 on March 25, 2013, 01:34:08 pmThats true, I once tried to charge an old lead-acid battery but it was just drawing current, and not charging.Maybe it's a good idea to just solder a fuse between the wires, to prevent it from happening again.
Agilent E3631A Specifications - help what the spec sheet actually means? - Page 1
Forum section: electronics / general

author: gerrysweeney
author_rank: Regular Contributor
timestamp: July 21, 2012, 10:49:16 am
content: Have a look at the programming accuracy specs on the data sheethttp://cp.literature.agilent.com/litweb/pdf/5990-4573EN.pdfAny idea how to interpret the programming accuracy when its expressed as 0.05%+20mV ?these are the specs I am trying to understand but I have no idea how to interpret what they actually mean. On the face of it the accuracy is not that great if I am reading it right. A 5v, 0.05% is about 25mV so that plus 20mV would suggest the programmed voltage output would be somewhere within 50mV of the programmed voltage. at the other extreme, it I set 100mV then 0.05% of that is only 500uV + 20mV which at this end would suggest the programmed output should be within 20% of the programmed ouput.Am I reading those specs correctly? Can anyone offer any insight?Interestingly enough the PSU design actually uses an Audio DAC which at least two people advised me was actually not a good idea (http://www.analog.com/static/imported-files/data_sheets/AD1851_1861.pdf) for a programmable PSU - go figure...Thanks

author: Bored@Work
author_rank: Super Contributor
timestamp: July 21, 2012, 01:39:45 pm
content: You have the right idea, but screwed up your math <insert obligatory rant about today's youth here>.5 V * 0.05% = 2.5 mVEdit: Regarding the DAC, if you check the datasheet you see a severe lack of information for non-audio applications. This is one of the reasons that makes using such a DAC hard in non-audio applications. Can you, at first glance, figure out if that DAC works down to 0 Hz, aka DC? And what do you do with the bipolar output? Adding an offset? That requires yet another good reference voltage. Or do you know how the DAC behaves during its 1 min warmup period?HP certainly knows more about that DAC then we know. Maybe Analog told them, or they measured it. Will Analog tell you, too, or do you want to run some test series to figure out the DAC? of course, if you like that DAC, go ahead, get a few, start measuring and designing.

author: gerrysweeney
author_rank: Regular Contributor
timestamp: March 27, 2013, 10:44:01 am
content: Thanks for the response bored@work, sorry I did not reply previously, I only just realised there was a response, I must have missed the mail notification - apologies if I appeared rude. You must be seriously old if you think I am todays youth....You are right, I dropped a decimal place.... Re the DAC, I see your point, its very clearly speced for audio yet HP decided to use it so I guess they done the measurements. Its clear though that it works down to DC, although because they mux the DAC output into some sample and hold circuits its never at a steady DC state, its output is around a few Hz - perhaps thats part of the scheme that allows an audio class DAC to work.Gerry
"On the Effectiveness of Aluminium Foil Helmets:  An Empirical Study" - Page 1
Forum section: electronics / general

author: reagle
author_rank: Unknown
timestamp: December 11, 2012, 12:37:02 am
content: Speaking of tinfoil hatshttp://berkeley.intel-research.net/arahimi/helmet/

author: Prizmatic
author_rank: Regular Contributor
timestamp: December 11, 2012, 12:44:28 am
content: Laaaa

author: reagle
author_rank: Unknown
timestamp: December 11, 2012, 01:12:03 am
content: Well, maybe Dave can make one up for this occasion?

author: mickpah
author_rank: Regular Contributor
timestamp: December 11, 2012, 01:14:17 am
content: here you go shameless pilfered from Mycotopia forum.

author: HardBoot
author_rank: Regular Contributor
timestamp: December 11, 2012, 04:54:50 am
content: The Conclusion is brilliant.

author: Moshly
author_rank: Regular Contributor
timestamp: March 27, 2013, 06:59:51 am
content: Doh, was going to show this to someone but the link is deadAnyone archive it ?

author: jhalar
author_rank: Regular Contributor
timestamp: March 27, 2013, 07:06:58 am
content: I think this archive is what you are looking for.http://archive.is/mkilq

author: grumpydoc
author_rank: Super Contributor
timestamp: March 27, 2013, 08:03:11 am
content: orhttp://web.archive.org/web/20130307180428/http://berkeley.intel-research.net/arahimi/helmet/
Wireless Communications in project - Page 1
Forum section: electronics / general

author: brendan-petrol
author_rank: Contributor
timestamp: March 26, 2013, 11:56:42 pm
content: Hello people!I am in the process of designing a PCB for a project I'm working on, and I want to put some low speed wireless communications in it.Would I be better off designing the PCB to fit around a pre-made module or looking for an IC to do that for me and designing it into the project?Thanks!Brendan

author: w2aew
author_rank: Super Contributor
timestamp: March 27, 2013, 12:13:47 am
content: Quote from: brendan-petrol on March 26, 2013, 11:56:42 pmUsing premade RF modules can save you the headaches of the Rf layout, antenna, etc. there are very inexpensive modules available today, like these:http://www.sparkfun.com/products/9582

author: c4757p
author_rank: Super Contributor
timestamp: March 27, 2013, 12:26:11 am
content: Yep. Normally I feel like I'm giving up with premade modules, but RF is one area where I'll use one. Saves you a ton of work and you usually end up with a nicer solution than if you did it yourself.

author: brendan-petrol
author_rank: Contributor
timestamp: March 27, 2013, 12:32:42 am
content: Would that choice make much of a difference if I decided to get a batch of boards fabricated?I imagine using an RF module would be better for once off prototypes, but designing one on-board would be better for mass produced boards?I was considering (depending on how it turned out) putting my project up on Kickstarter to get a batch fabricated...
ASCE American Society of Civil Engineers  - Page 1
Forum section: electronics / general

author: ErikTheNorwegian
author_rank: Frequent Contributor
timestamp: March 24, 2013, 07:23:09 pm
content: [im

author: SeanB
author_rank: Super Contributor
timestamp: March 25, 2013, 07:58:50 pm
content: Pretty much describes a lot of countries.
trying to source 11kohm cement resistor - Page 1
Forum section: electronics / general

author: jbomba
author_rank: Contributor
timestamp: March 24, 2013, 10:46:12 am
content: Hi im doing some repairs on an air con inverter board and the 11k cement resistor has blown out. Ive had an extensive search online and the only cement resistor close is 10k im chasing a vertically orientated one with both pins on the bottom. Can anyone help me out?

author: Psi
author_rank: Super Contributor
timestamp: March 24, 2013, 11:54:22 am
content: Just a thought, maybe the wattage would be useful infoIn any case. you'll probably have to use multiple resistors if you need 11k exactly at high power levels

author: Unknown
author_rank: Unknown
timestamp: March 24, 2013, 02:22:43 pm
content: Here is a USA supplier; look through the metal film at 1% values... I doubt you can get ceramic as it's non-standard,most likely produced for this product ? anyway see URL below:http://www.talonix.com/shop/category.aspx?catid=64

author: lewis
author_rank: Frequent Contributor
timestamp: March 24, 2013, 03:44:58 pm
content: Stick this in endways?http://uk.farnell.com/multicomp/mcprw0awjp113b00/resistor-metal-film-11kohm-10w/dp/1737537

author: tom66
author_rank: Super Contributor
timestamp: March 24, 2013, 04:48:02 pm
content: Or two 22kohm in parallel. You could use resistors of half the power rating, if size is a problem.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: March 24, 2013, 04:54:25 pm
content: Use a 10K axial part and a 1K next to it, both vertical. Remember the 1K will only have 10% of the dissipation so it can be smaller.

author: jbomba
author_rank: Contributor
timestamp: March 25, 2013, 11:38:10 am
content: Sorry its 5w guysSent from my Nexus 7 using Tapatalk HD

author: kxenos
author_rank: Frequent Contributor
timestamp: March 25, 2013, 11:49:15 am
content: Or you can just use a 10k. It'll be just about 1mA difference in the input current (22.36mA vs 21.32mA of the original). I assumed it's the mains input fusable resistor of an SMPS. If that's the case you should also check the FET for shortcircuit before powering up.

author: jbomba
author_rank: Contributor
timestamp: March 25, 2013, 12:10:04 pm
content: I take it these can just be hooked up in series?Sent from my Nexus 7 using Tapatalk HD
cheap indium USA made solder - Page 1
Forum section: electronics / general

author: peterthenovice
author_rank: Regular Contributor
timestamp: March 24, 2013, 09:26:36 pm
content: I was browsing for some cheap but decent solder. I found this .032" diameter 63/37 1 lb. spool. Has any body bought this brand?http://www.amazon.com/Indium-Wire-Solder-CW-807-Spool/dp/B003AYJWSY/ref=sr_1_1?ie=UTF8&qid=1364159882&sr=8-1&keywords=63sn%2F37pb+solder
Sparkfun now selling Hakko FX888D - Page 1
Forum section: electronics / general

author: space_bastard
author_rank: Newbie
timestamp: March 16, 2013, 11:35:50 pm
content: Hey all, new user here. On Friday I saw that Sparkfun now stocks the digital version of the Hakko FX888, the FX888D. Not a bad deal at $99.95 (as of 2013-03-16). If I didn't already have my Weller WES-51, I would almost definitely get one. Thought I'd post the link in case anyone is interested.https://www.sparkfun.com/products/11704

author: mariush
author_rank: Super Contributor
timestamp: March 16, 2013, 11:41:53 pm
content: There's an authorized distributor on ebay that sells the old non-digital one for 84$ plus shipping and the new one for around 92$http://stores.ebay.com/NEI-Lamps-and-Electronics/HAKKO-SOLDERING-STATIONS-/_i.html?_fsub=16378302&_sid=82105093&_trksid=p4634.c0.m322

author: space_bastard
author_rank: Newbie
timestamp: March 16, 2013, 11:57:23 pm
content: Quote from: mariush on March 16, 2013, 11:41:53 pmCool, thanks for the link mariush!I'll have to bookmark that.

author: ivan747
author_rank: Super Contributor
timestamp: March 17, 2013, 01:59:37 am
content: For how long will they keep selling the analog version?

author: Quick5pnt0
author_rank: Contributor
timestamp: March 24, 2013, 10:30:56 am
content: Just picked one up on ebay for $84 by using the "make offer" button.

author: jbomba
author_rank: Contributor
timestamp: March 24, 2013, 10:47:33 am
content: i own the fx888 they really are a fantastic iron

author: stryker
author_rank: Regular Contributor
timestamp: March 24, 2013, 01:15:06 pm
content: Where's the best place anyone's found for a source of Australian Hakko FX-888Ds? RS sell only the analog one (which would be fine, but my price from there is $172). LittleBird aren't stocking the Sparkfun one since presumably they only get the 120V US version, as does Adafruit and the eBay link listed above is also 120V.Thanks, Geoff

author: Jorge.fv
author_rank: Contributor
timestamp: March 24, 2013, 02:02:28 pm
content: Quote from: mariush on March 16, 2013, 11:41:53 pmThat’s a nice one but they don’t ship to Bolivia, I think Sparkfun is my only option since they ship everywhere sadly there is only 120V version.
sheild wire to earth ground or dc ground? - Page 1
Forum section: electronics / general

author: ftransform
author_rank: Frequent Contributor
timestamp: March 22, 2013, 07:41:27 pm
content: So I asked this in another thread of mine but I am anxious to etch my PCB today so I ask again, should I connect the shield wire for my device to earth ground or the DC ground?When I prototyped my circuit on a breadboard I used a large metal bowl to try to shield it from common mode noise. I hooked up this bowl to earth ground and there was no effect on my measurement. When I connected the bowl to DC ground the noise level dropped drastically.I have not experimented with shield wire before but given the results I have from my bowl shielding experiment I am inclined to connect it to DC ground. If I put a can shield around my project I would also be inclined to connect it to DC ground.Am I making a mistake?

author: SeanB
author_rank: Super Contributor
timestamp: March 22, 2013, 07:54:12 pm
content: DC ground, otherwise you are actually coupling the noise into the circuit. If you want make a component position between DC ground, the shield and the earth ground so that you can leave it open, place a shorting link or a wire with a ferrite bead on it in the component position.

author: ftransform
author_rank: Frequent Contributor
timestamp: March 22, 2013, 08:35:18 pm
content: thank you.

author: codeboy2k
author_rank: Super Contributor
timestamp: March 24, 2013, 01:03:46 pm
content: Quote from: SeanB on March 22, 2013, 07:54:12 pmThis is good practice. My first run of a prototype board often has a multitude of open spaces and/or zero ohm resistors in places where I think I might need an actual resistor, or to choose between multiple connections, or to decide if a bead is needed in production, etc. ...For op amps, I often leave extra space for paralleling additional resistors and capacitors into the feedback loops.I often leave room for another filter cap on the power supply in case I need to reduce the ripple some more, etc.If I am not sure whether I will need an op amp in circuit or not (i.e. a buffer that may or may not be needed) then I'll put the part in as a DNI and then bypass the input to the output with a zero ohm. If I find I need it I can put it in later, remove the 0-ohm and test the prototype that way too.These little things make the first run prototype more useful as a test platform.
The chinese have don it again - Page 1
Forum section: electronics / general

author: peterthenovice
author_rank: Regular Contributor
timestamp: March 23, 2013, 07:57:50 pm
content: I found this device on ebay it "claims" that has a usb to i2c/spi converter/ocilliscope/logic analyser/wave generator/avr programer/uart/http://www.ebay.com/itm/USB-to-I2C-SPI-Converter-Oscilloscope-AVR-Arduino-/120992210387?pt=LH_DefaultDomain_0&hash=item1c2bb29dd3

author: westfw
author_rank: Super Contributor
timestamp: March 23, 2013, 08:18:36 pm
content: The whole USBASP clone situation is "interesting."That that circuit would get cloned in China and widely sold is somewhat predictable.But there are SO MANY clones, many slightly different from each other. So they're not JUST clones, but somewhat legitimate "re-engineered" implementations...

author: tom66
author_rank: Super Contributor
timestamp: March 23, 2013, 11:16:10 pm
content: I don't call an 8-bit <2Msps ADC an "oscilloscope".No accurate time base (cheap +/-100ppm xtal?), no adjustable voltage scale, no vertical offset, no AC/DC coupling, probably very limited triggering...It's a "waveform viewer", at best.

author: JuKu
author_rank: Frequent Contributor
timestamp: March 24, 2013, 09:04:50 am
content: Quote from: tom66 on March 23, 2013, 11:16:10 pmNow, what does the word "oscilloscope" literally mean?

author: mzzj
author_rank: Super Contributor
timestamp: March 24, 2013, 09:44:06 am
content: Quote from: tom66 on March 23, 2013, 11:16:10 pm"oscilloscope" timebase accuracy? How do you even read scope screen better than 10 000 ppm (yes, ten thousand ppm) accuracy ?
Compaq CQ61-231TU Display Problem - Page 1
Forum section: electronics / general

author: maxpayne
author_rank: Regular Contributor
timestamp: March 24, 2013, 08:06:58 am
content: I have facing an unusual problem in my laptop. Sometimes the display works, sometimes it does not. All I can see is a faint image during boot-up, when the problem arises. I have uploaded a video so that you can understand what the problem is ..Unable to find the cause of this problem. Is the LCD gone ? I guess it is not as sometimes it works without no problem.or the back-light inverter is not working ?I connected an external monitor to its VGA output and no problem at all at this port. Display is shown perfectly.Searching the net I didn't find any problem like this ...How I can fix it ? I have experience of dissembling my laptop...

author: SeanB
author_rank: Super Contributor
timestamp: March 24, 2013, 08:39:17 am
content: Backlight inverter or the flexible wring between the 2 halves. Another thing is to check the connectors are both pushed in all the way and latched on the flexible cables, and that the ends have not peeled back to make intermittent contact. Does it come on or go off as you close the case, then points to the flex cable being faulty or loose.

author: G7PSK
author_rank: Super Contributor
timestamp: March 24, 2013, 09:04:36 am
content: If you can see an faint image when the screen is blacked out it is most likely due to a fault in the backlight system either power to or from the inverter I have seen the same problem though where the problem lay with the switching between internal and external monitor.

author: maxpayne
author_rank: Regular Contributor
timestamp: March 24, 2013, 09:08:54 am
content: Quote from: SeanB on March 24, 2013, 08:39:17 amthis problem does not depends on whether I close or open the case. sometimes the problem arise and remains the same... sometimes everything is normal. I am thinking of having a look inside to check the cables....
Time-Life "Understanding Computers" series (1990) - Page 1
Forum section: electronics / general

author: FenderBender
author_rank: Super Contributor
timestamp: March 24, 2013, 09:54:40 pm
content: Hi everyone,Today a local senior-citizens organization was having a booksale. A grocery bag full of books for $5. I found a whole collection of books published by Time-Life circa 1990 called "Understanding Computers". There appears to be around 9-10 books in the series. They had 8 there. I picked up all of them. I am really enjoying them. Fantastic illustrations and it's great for learning the basic operation of computers from an electronics standpoint. I'm finding them to be a great intro to digital design, which I know very little about.I'm still on the first book and I've learn a lot about adders and logic and even the process of manufacturing ICs. Of course, you could probably find this all online, but I really like these.Has anyone else owned any of these? Any of your own thoughts?If you want your own, they are on Amazon, used of course, some of them as low as $2.

author: peterthenovice
author_rank: Regular Contributor
timestamp: March 25, 2013, 12:47:39 am
content: I cant seem to theme online

author: FenderBender
author_rank: Super Contributor
timestamp: March 25, 2013, 01:05:34 am
content: http://www.amazon.com/Time-Life-Books-Understanding-Computers-Volumes/dp/B000UUX462That's all of them, but individually they are very cheap.

author: 1.21 gigawhats
author_rank: Newbie
timestamp: March 25, 2013, 01:30:33 am
content: Wow, we had this as a set when I was a younger lad.I spent HOURS reading them and checking out the great illustrations.I should see if they're still in a box in the shed at my folks house, I'm sure it would be funny to see what was cutting edge in computer graphics at the time!Ahh, good old times...Mark

author: FenderBender
author_rank: Super Contributor
timestamp: March 25, 2013, 02:18:04 am
content: Well this is new news to me. I was still negative 4 years old when these were published. But really I've been reading them (mostly just the science/design part for now, history later). I'm learning how memory works. Illustrations are superb as you say.Hard for anyone to have any idea what I'm talking about if you haven't actually seen them. They aren't really much of engineering books per say, but they are a wealth of knowledge.
Super Bowl big fail - Page 1
Forum section: electronics / general

author: NiHaoMike
author_rank: Super Contributor
timestamp: February 09, 2013, 02:16:19 am
content: http://arstechnica.com/information-technology/2013/02/cause-of-super-bowl-blackout-installed-to-prevent-super-bowl-blackout/

author: UPI
author_rank: Regular Contributor
timestamp: March 22, 2013, 04:23:54 am
content: Conclusion: Based on this engineer’s training, education, experience, and available evidence, inthe context of the investigation that was performed, this engineer has developed the followingconclusions to a reasonable degree of engineering certainty:1. The cause of the power outage was a misoperation of the relay.2. A contributing factor to the misoperation of the relay was the unstable operating conditionof the relay around the setpoint of the subject relay due to a design defect.3. A contributing factor of the outage was the inappropriate current trip level setting of therelay, which was the factory default value.4. A contributing factor to the inappropriate setting was inadequate communication betweenthe manufacturer and the utility.The opinions and conclusions expressed in this report are based on the information available tothe engineer as of the date of this report. If additional information becomes available thataffects these opinions and conclusions, this engineer reserves the right to supplement thisreport.I would really hate to be responsible for any part of this mess.
[OT] Always check the back seat when driving in Daveland - Page 1
Forum section: electronics / general

author: Bored@Work
author_rank: Super Contributor
timestamp: March 21, 2013, 09:45:17 am
content: Not electronic related whatsoeverhttp://www.abc.net.au/news/2013-03-19/palumpa-problem-croc-schot/4581876

author: KJDS
author_rank: Super Contributor
timestamp: March 21, 2013, 10:00:53 am
content: Pah, me n the dog would be safe in the front. What's in the back is the wife's problem

author: SeanB
author_rank: Super Contributor
timestamp: March 21, 2013, 10:19:04 am
content: With some women that would mean they would have new crocodile skin shoes in a short time, along with a good set of steaks for the barbie.

author: GK
author_rank: Super Contributor
timestamp: March 21, 2013, 10:34:04 am
content: Anyone here watchTurtle Man? This evening they had six or seven grown men playing Rambo to catch a freaking squirrel. What a load of bullshit.

author: ivan747
author_rank: Super Contributor
timestamp: March 21, 2013, 10:35:10 am
content: They found this near a gold mine:

author: GeoffS
author_rank: Unknown
timestamp: March 21, 2013, 10:55:15 am
content: For some people. a dog in the back of the ute is just not enough.

author: smashedProton
author_rank: Frequent Contributor
timestamp: March 21, 2013, 02:45:18 pm
content: Somebody needs to give that snake an antacid tablet!
Toshiba laptop service manuals - You cannot haz! - Page 1
Forum section: electronics / general

author: TerraHertz
author_rank: Super Contributor
timestamp: March 20, 2013, 01:53:59 am
content: http://www.wired.com/opinion/2012/11/cease-and-desist-manuals-planned-obsolescence/?mwh=1http://www.tim.id.au/blog/tims-laptop-service-manuals/http://www.reddit.com/r/technology/comments/12ydou/for_three_years_i_have_run_tims_laptop_manuals/QuoteWish I'd known about thatbeforethe manuals got pulled.Now to check it for the other laptops I have.

author: PedroDaGr8
author_rank: Super Contributor
timestamp: March 20, 2013, 03:13:49 am
content: Toshibas are some of the easiest machines to repair. My family (and fathers dental practice) have owned around 20-30 plus toshibas. The ones at the dental office were abused pretty heavily but I never had a problem repairing them.

author: amyk
author_rank: Super Contributor
timestamp: March 20, 2013, 11:05:22 am
content: http://en.wikipedia.org/wiki/Streisand_effectworks well... the Internet is big enough. In other news, full schematics are available for laptops and various other electronics if you know where to look too. Apparently component-level motherboard repair is customarily practiced in the East.

author: carloscuev
author_rank: Regular Contributor
timestamp: March 20, 2013, 11:47:14 am
content: If someone could point me to the right website (here or via PM) I would be grateful, I have an old Toshiba A205-S4607 that stopped working about 2 years ago, just bought a new one because I was in a hurry to finish a design.Now I'm looking to repair it, it reboots when powered from the power adapter, but from battery works fine. Putting a diode to drom 0.7v from the adapter works and tells be that the problem is when powered from 19v from the adapter. So may be bad caps I guess... but first I made this:http://forums.toshiba.com/tshb/attachments/tshb/brd_batt_pwr/6918/1/DSCN0692.jpgthen I got some NEC TOKIN OE128 caps and replaced it but only worked a few weeks and problems continued to appear.I need it for its expresscard port the new one doesn't have(Why are manufacturers doing this?) Anyway I would like to download any documentation available and if someone had this problem or know where to look to diagnose and repair it would be very nice.
Nice Solder Work - 20 Years Ago - Page 1
Forum section: electronics / general

author: Mike Warren
author_rank: Unknown
timestamp: March 15, 2013, 05:00:31 am
content: I have a crappy 20 year old Digitor (Dick Smith) CRO. One channel stopped working about 2 years ago, and the the other channel developed an intermittent problem a few months after that, so it's been switched off for about a year.I thought I'd have a quick look at it today to see if I can get it going again easily. The first step was to check the electrolytic capacitors. When I touched one I heard a slight crack and it started flopping around. I unsoldered it and the copper was bare underneath. I poked at a few others and the same thing happened. The joints look quite good on the surface, but the solder never took to the copper. The PCB must have had surface oxidisation before it was populated. Obviously, no plating or HASL was used.I'm surprised it lasted as long as it did.Fortunately, only one board suffers from this, so I will put a couple of hours into it (resoldering and changing electros) and see if that's all it needs. Not worth putting too much effort in to it.

author: Mike Warren
author_rank: Unknown
timestamp: March 21, 2013, 01:50:15 am
content: Done.

author: c4757p
author_rank: Super Contributor
timestamp: March 21, 2013, 01:51:58 am
content: "Digitor" is a hilarious brand name for an oscilloscope that is so analog that it appears not to even have an MCU/MPU for control functions.

author: Mike Warren
author_rank: Unknown
timestamp: March 21, 2013, 01:55:28 am
content: Only analogue circuitry inside this.
PSI - the drought has broken - Page 1
Forum section: electronics / general

author: notsob
author_rank: Frequent Contributor
timestamp: March 20, 2013, 01:21:09 am
content: Marmite returns to New Zealand shop shelveshttp://www.news.com.au/lifestyle/food/nzs-marmageddon-is-over/story-fneuz8zj-1226601101330Cheers mate

author: Psi
author_rank: Super Contributor
timestamp: March 20, 2013, 01:41:51 am
content: Finally

author: peter.mitchell
author_rank: Super Contributor
timestamp: March 20, 2013, 08:36:36 am
content: Wash it down with some L&P.

author: digsys
author_rank: Unknown
timestamp: March 20, 2013, 08:43:06 am
content: That stuff is foul ! Vegemite RULES !! Long live Vegemite

author: Psi
author_rank: Super Contributor
timestamp: March 20, 2013, 08:53:26 am
content: What a troll

author: GK
author_rank: Super Contributor
timestamp: March 20, 2013, 12:07:02 pm
content: Couldn't you have just gone down to Supercheap Auto in the interim and bought a tub of bearing grease?

author: AlfBaz
author_rank: Super Contributor
timestamp: March 20, 2013, 12:46:48 pm
content: Being an electronics forum we should be pushing tricky Dicky's Ozemite

author: Bored@Work
author_rank: Super Contributor
timestamp: March 20, 2013, 02:34:37 pm
content: Quote from: GK on March 20, 2013, 12:07:02 pmNa, bearing grease has some taste. Can't have that.

author: SeanB
author_rank: Super Contributor
timestamp: March 20, 2013, 06:59:01 pm
content: The factory by me is moving, the land is finally worth selling. Means I will no longer be able to tell which way the wind is blowing though. I like the smell of brewers yeast. The taste is great as well, especially fresh off the drier at the brewery.

author: GK
author_rank: Super Contributor
timestamp: March 20, 2013, 11:49:25 pm
content: I think the stuff can be called a lot of things, but certainly not tasteless. Then there is the salt content. You might as well be sucking half a bottle of soy sauce for breakfast.
Telephone Insecurity - Page 1
Forum section: electronics / general

author: Sionyn
author_rank: Frequent Contributor
timestamp: March 20, 2013, 06:55:37 pm
content: makes for some harrowing readingsecurity researcher pisses off a script kiddie who then spoofs his telephone number, calls the police telling them his wife has been shot by Russian gang. unaware of this he is cleaning his house expecting guests over, when armed police turn and point their guns at him.https://krebsonsecurity.com/2013/03/the-world-has-no-room-for-cowards/
7 hundred thousand embed devices use to construct botnet - Page 1
Forum section: electronics / general

author: Sionyn
author_rank: Frequent Contributor
timestamp: March 20, 2013, 11:08:44 pm
content: 7 hundred thousand embed devices the likes of printers and routers have been found to have telnet servers running on public side interfaces exposed to the internet. this guy accumulated these device port scanning the whole ip4 range finding 420 million devices responding to his icmp requests infecting 70 7 hundred thousand of them.baggers why are these things running telnet servers debugging ? poor implementation [most likely] ?http://internetcensus2012.bitbucket.org/paper.html

author: AlfBaz
author_rank: Super Contributor
timestamp: March 21, 2013, 03:28:55 am
content: This sort of thing must be going on all the time, although probably by less honest people.Years ago whilst testing an embedded TCP/IP stack I exposed the device to the net, within minutes it was being port scanned... maybe the ISP

author: Hypernova
author_rank: Unknown
timestamp: March 21, 2013, 09:08:57 am
content: On the world map, Canada looks surprisingly empty?

author: poodyp
author_rank: Regular Contributor
timestamp: March 21, 2013, 10:28:47 am
content: Quote from: Hypernova on March 21, 2013, 09:08:57 amCanada is pretty empty. 3.3 people per square kilometer.

author: kripton2035
author_rank: Super Contributor
timestamp: March 21, 2013, 10:30:50 am
content: Quote from: Hypernova on March 21, 2013, 09:08:57 amyes surprising !even pretty empty they have computer no ? it's almost as empty as africa !

author: andersm
author_rank: Super Contributor
timestamp: March 21, 2013, 12:14:14 pm
content: Possibly apocryphal, but I remember hearing about warez ftp sites being found running on network printers years ago.
Strip/veroboard on digikey - Page 1
Forum section: electronics / general

author: hanndoddi
author_rank: Contributor
timestamp: March 21, 2013, 12:09:19 am
content: Hello every one i was looking for veroboards on digikey supriced i did not find any.Either digikey is not selling veroboards of the have a different name.Does any one know?Or maby know a different name used?And other Q: I looking for a big veroboard A4 size any one know how big veroboards go?

author: c4757p
author_rank: Super Contributor
timestamp: March 21, 2013, 12:18:09 am
content: I doubt DigiKey sells stripboard. I keep some around for quick, bodgey prototypes; I get ithere.Quote from: hanndoddi on March 21, 2013, 12:09:19 amHereis a 205x410mm one, just 5mm shy of A4 in width and longer than A4.

author: mariush
author_rank: Super Contributor
timestamp: March 21, 2013, 12:34:38 am
content: Farnell/Newark has a lot of prototyping boards... but they're not cheap and they may only stock a large percent of them in UK (so you would have to pay 20$ or something like that on each package):http://www.newark.com/jsp/search/browse.jsp?N=201028+422&ref=lookaheadI personally tried the Roth 100x160 mm veroboards and they're of very good quality, FR2, can't complain, but like I said they're not cheap.There's boards that look good on eBay for less money, so when I need more boards, I'm probably going to give a few sellers a try.

author: Psi
author_rank: Super Contributor
timestamp: March 21, 2013, 12:35:54 am
content: Digikey seem to have quite a few names for it, breadboard, PC board, Vectorbord, Circbord.Its all under 'Prototyping Products' - 'Prototype Boards Perforated'http://www.digikey.com/scripts/DkSearch/dksus.dll?x=0&y=0&lang=en&site=us&KeyWords=V2018-ND

author: c4757p
author_rank: Super Contributor
timestamp: March 21, 2013, 12:39:10 am
content: Psi, I stand corrected! Didn't think they'd have it, but I didn't bother to check.

author: FenderBender
author_rank: Super Contributor
timestamp: March 21, 2013, 09:36:10 pm
content: You can find much better ones on eBay from Chinese sellers, in my opinion. I've bought many FR4 double sided, plated-through-hole proto boards off eBay for relatively cheap.

author: c4757p
author_rank: Super Contributor
timestamp: March 21, 2013, 09:43:01 pm
content: Quote from: FenderBender on March 21, 2013, 09:36:10 pmI actually really like the traditional stripboard for quick stuff. Single-sided means I can run bare wires anywhere on one side without worrying about contact, phenolic means it's ridiculously easy to cut - I just score it with a knife a couple times and snap, and the strips can eliminate a lot of wires if you're clever with placement. A quick twist of a sharp drill bit breaks the strips easily. I think I'd just run off a PCB (takes me about a half hour from layout-complete to holding the board in my hand) for anything that I'd use that style of board for.
Where to find high voltage electrolytics - Page 1
Forum section: electronics / general

author: G7PSK
author_rank: Super Contributor
timestamp: March 18, 2013, 04:16:58 pm
content: Hi, I need to find a source of high voltage electrolytic capacitors that wont cost an arm and a leg.The one I am looking for at present is 5nF (0.005 micro farads) at 1000 volts non polarized electrolytic. This is on an old radio dating to 1947.

author: rsjsouza
author_rank: Super Contributor
timestamp: March 18, 2013, 04:48:54 pm
content: I have been in a similar situation before, and I replaced it with a ceramic or disc cap without apparent problems (it was a 1957 radio). Would that work for you, given that high voltage ceramic caps are easier to find?

author: mzzj
author_rank: Super Contributor
timestamp: March 18, 2013, 04:54:20 pm
content: Quote from: G7PSK on March 18, 2013, 04:16:58 pmElectrolytic? Sounds like trouble to find...Maybe you can replace it with 4.7nF ceramic or plastic capacitor + series resistor to "crappify" the plastic cap to same level as the orginal.

author: Radio Tech
author_rank: Frequent Contributor
timestamp: March 18, 2013, 05:04:32 pm
content: I mostly replace them with the "orange drop" type caps. Been doing that for years. Some of these electrolytic caps are impossible to find.

author: G7PSK
author_rank: Super Contributor
timestamp: March 18, 2013, 06:12:19 pm
content: Thanks for that. I have now found some 4.7nF polyester caps at 1000 volts DC. Dont know why they chose such a high voltage as the HT voltage is only 120 volts from a battery so for much of the time it is lower than that assuming that the battery voltage dropped during use.

author: SeanB
author_rank: Super Contributor
timestamp: March 18, 2013, 07:18:37 pm
content: With a HT of 120V from a B+ battery any cap above 160V will work for supply decoupling. Myself I would increase the value to 100n 250V polyester, unless it is a screen grid, where I would use the original value but rated for 3 times the battery voltage as the screen can be driven to double the supply in a push pull amplifier with output transformer. You can use a 4n7 630V unit there.

author: G7PSK
author_rank: Super Contributor
timestamp: March 18, 2013, 09:29:22 pm
content: Quote from: SeanB on March 18, 2013, 07:18:37 pmIt is actually across the input to the speaker impedance matching transformer, but all the capacitors are rated at a 1000 volts on this radio, obviously they wanted to make sure the radio would last until some one got around to inventing microchips.
Ian M. Ross, a President at Bell Labs, Dies at 85 - Page 1
Forum section: electronics / general

author: ErikTheNorwegian
author_rank: Frequent Contributor
timestamp: March 17, 2013, 09:17:28 pm
content: Ian

author: emc2
author_rank: Newbie
timestamp: March 18, 2013, 01:58:06 am
content: rip

author: smashedProton
author_rank: Frequent Contributor
timestamp: March 18, 2013, 02:16:43 am
content: Oh Gee would I like to be smart enough to have a Foreign EE write about me!

author: Amarbir[Lynx-India]
author_rank: Frequent Contributor
timestamp: March 18, 2013, 12:19:06 pm
content: Quote from: smashedProton on March 18, 2013, 02:16:43 amBut Sir ,You Are SmashedProton.RIP To The Gentlemen Legend
restoring of a Tek 555 - Page 1
Forum section: electronics / general

author: Martin.M
author_rank: Frequent Contributor
timestamp: March 17, 2013, 02:40:17 pm
content: hello friends,I have restorated the second triple nickel.Have fun to see some pictures from this glowing wonder,http://www.wellenkino.de/555Plugged with 2 dual trace plugins CA there are 117 tubes glowing, eating 1kW.This scope have a scope mobile and external PSU.I have worked like in the old time, with an tube voltmeter + HV probe.greetings from germanyMartin

author: Unknown
author_rank: Unknown
timestamp: March 17, 2013, 09:21:24 pm
content: Jesus, that 555 takes me back, nice images and work your doing.
nice tutorial on steppers - Page 1
Forum section: electronics / general

author: SparkeyinVA
author_rank: Newbie
timestamp: March 18, 2013, 09:02:38 pm
content: Good presentation on Stepper motors<iframe src="http://www.slideshare.net/slideshow/embed_code/10124404" width="427" height="356" frameborder="0" marginwidth="0" marginheight="0" scrolling="no" style="border:1px solid #CCC;border-width:1px 1px 0;margin-bottom:5px" allowfullscreen webkitallowfullscreen mozallowfullscreen> </iframe> <div style="margin-bottom:5px"> <strong> <a href="http://www.slideshare.net/Servo2Go/nippon-pulse-america-unraveling-the-mystery-of-stepper-motor-technology-presentation-10124404" title="Nippon Pulse America unraveling the mystery of stepper motor technology presentation" target="_blank">Nippon Pulse America unraveling the mystery of stepper motor technology presentation </strong> from <strong><a href="http://www.slideshare.net/Servo2Go" target="_blank">Servo2Go.com</strong> </div>

author: KJDS
author_rank: Super Contributor
timestamp: March 18, 2013, 10:51:13 pm
content: That's a useful refresher, especially as i need to sort out a stepper motor driver in the next few weeks.
Boston electronics? - Page 1
Forum section: electronics / general

author: hanndoddi
author_rank: Contributor
timestamp: March 16, 2013, 11:47:37 pm
content: Any one know any good electronics related places in Boston to see?Maby some good stores?

author: JuiceKing
author_rank: Regular Contributor
timestamp: March 17, 2013, 12:26:23 am
content: Quote from: hanndoddi on March 16, 2013, 11:47:37 pmI live in Boston. Better than most for this, I guess, but it's no Silicon Valley.There's You-Do-It, in Needham, the best-stocked hobbyist store around. Several notches up from Radio Shack, but worth a special trip?Come spring, the monthly MIT Flea Market in Cambridge will resume. That's fun!Check out the Mark I computer in the Science Center in Harvard if you're in the neighborhood.What am I overlooking?Glad you asked..hope others can tell me about places I don't know.

author: SteigsdB
author_rank: Contributor
timestamp: March 17, 2013, 12:26:53 am
content: You Blew It... Er.. You Do It Electronics down by 128 and Rt 9.

author: Corporate666
author_rank: Unknown
timestamp: March 17, 2013, 05:34:03 am
content: Depending on how far you want to go, there is Electronic Surplus Supply in Manchester, NH... but it's quite a ride from Boston (an hour or so).

author: SteigsdB
author_rank: Contributor
timestamp: March 17, 2013, 07:25:34 am
content: The name escapes me, but wasn't there a place off 95 down by Attleboro or just perhaps over the line in RI?Jabbour's I think it was.
2 resonable new engineering songs / vids - Page 1
Forum section: electronics / general

author: Spikee
author_rank: Frequent Contributor
timestamp: March 20, 2013, 11:20:03 pm
content: I don't know if this has been posted before ... But i just found it and it is pretty awesome.It is even @ youtube trends, male ANDfemales.Channel:https://www.youtube.com/user/OfficialENGR
Video microscope! - Page 1
Forum section: electronics / general

author: iXod
author_rank: Frequent Contributor
timestamp: March 15, 2013, 07:45:43 pm
content: Great review(s) re. your ultimate microscope, the Mantis. Pure envy!But for those of us without $3K-plus in our budget -- I've always thought how nice it would be to make my own video microscope: a small close-up (variable focal-length?) video camera and a small display (6" minimum) with a port for larger monitors.How about your next project, Dave?Cheers.

author: PA0PBZ
author_rank: Super Contributor
timestamp: March 15, 2013, 07:58:54 pm
content: These things are quite handy:https://www.google.com/search?q=usb+microscope&tbm=ischOf course, as with everything, there is the good, the bad and the ugly. I have one that costed me like $50 and it is ok for the occasional need to have a good enlarged look at something.

author: iXod
author_rank: Frequent Contributor
timestamp: March 15, 2013, 08:46:51 pm
content: Problem with most of these is focal distance is small. Need working distance enough to solder and see something that might be taller than a PCB.Also ideal is a 5 or 6 inch LCD display mounted right below so I can look down, rather than larger monitor so you don't have to be looking elsewhere than down (makes for weird hand coordination and neck problems).

author: Unknown
author_rank: Unknown
timestamp: March 15, 2013, 09:34:57 pm
content: Useful tip their Fran... good for those individuals who are on a low monetary budget, and wish to experiment.Unfortunately my age now and eyesight is problematic,unable to see SMD or even want too now days;so sticking with through-hole electronics for my projects while stocks last, and where available; so as theinterest takes me, to spend time at the bench.Although after any useful experiment, with a wanted or good outcome,I spend far more time drawing out the circuit,drafting the enclosure details to a manufacturing level; it's a hard habit to break,after so many years in R&D.

author: iXod
author_rank: Frequent Contributor
timestamp: March 16, 2013, 06:41:51 pm
content: Fran,Nice "home tech".What video camera are you using to take those vids?Thanks.

author: bradleytron
author_rank: Regular Contributor
timestamp: March 16, 2013, 09:13:07 pm
content: That is a great idea, never thought to combine a couple low cost loupes to get a working microscope. Lots of potential for use with other projects! Thanks for the insight Fran.
IET. Worth it? - Page 1
Forum section: electronics / general

author: tom66
author_rank: Super Contributor
timestamp: March 16, 2013, 01:40:21 am
content: My university gives me four years IET membership for £10/year, so I've signed up for it. I get a pretty magazine every so often but I haven't used any other services.But I don't know if I'll benefit particularly from it outside of university (as I think it's closer to £120/year.)Does anyone have any opinion of the IET? Is it worth considering future membership?I'm looking to become an electronics engineer (will leave with MEng), with an analog/power electronics focus, if that matters.

author: Neilm
author_rank: Super Contributor
timestamp: March 16, 2013, 11:37:09 am
content: It is useful to have the letters after your name. It shows that you are professional enough to want to keep up with the trends in electronics. Also could help when applying for a job. I know when I left Uni (97) I got some job interviews at firms who had a requirement of "must be in IEE" (as it was then). All they have to go on are the projects you have done so they are looking for anything that will indicate you are serious about your chosen profession.Neil (MIET)

author: AndyC_772
author_rank: Super Contributor
timestamp: March 16, 2013, 12:02:01 pm
content: When I was a student, the company I was working for during the holidays was very keen on IEE membership, and signed up all the apprentices for it.I left them on graduation, and never actually went as far as getting full membership and a CEng, though - and it's not affected my professional career in the slightest. I've only ever even met one or two members that I'm aware of, and nobody important has ever suggested to me that I should join.Personally I'd be very wary of companies who consider the extra letters after your name as being more important, or even anywhere near as important, as your skills, knowledge and interest in electronics.

author: amiq
author_rank: Regular Contributor
timestamp: March 16, 2013, 01:26:38 pm
content: The only reason that I keep paying my dues is to maintain Chartered Engineer status. Is there any benefit in being a Chartered Engineer? If your field is electronics then probably not, if you want to be an Electrical Engineer then it certainly is. Likewise when/if you move into management it is useful. In certain fields (Oil/Gas/Energy) Chartered Status will always be asked for.If you want to become Chartered and are not to keen on the IET there are other insitutions that you can join through which you can obtain Chartered status.Amiq (CEng IEE)