hybridfree/eevblog-posts huggingface dataset:
eBay TTL fingerprint sensor help - Page 1
Forum section: electronics / beginners

author: CountParadox
author_rank: Contributor
timestamp: December 20, 2014, 07:34:10 am
content: Hello there all!tl;dr fingerprint scanner wont scan. plz help.Since I never properly introduced myself allow me to do so now. Count is the name, Science is the game.Now, I have this:http://www.ebay.com.au/itm/231184687980That a friend got me for my birthday. Now, on the eBay page it has the same 4 wires as the adafruit version as seen here:http://www.adafruit.com/product/751But the one I got has 6 wires not 4, and get this, two red, two black, and two green =_="Eventually after some testing I have figured out which is which, with the help of THIS manualish thing:http://lewys.eu/eevblog/fingerPrint_sensor_User_Manual_eng.docWhen I test with the PC program the seller sent me, i get nothing. always get a password or COM error :/For reference, that program is mirrored here:http://lewys.eu/eevblog/SFGDemoV2.0.rarnow, I tested some of the adafruit example sketches using a 3.3v modded arduino UNO and the fingerprint scanner comes to life, lights up red, and the serial monitor says that it found the scanner! (i tested without it connected, and with rx/tx swapped to make sure it doesnt always say this, and it only says it when connected right.)so I know its talking properly.But when the sketch says 'waiting for finger' I place my finger on the scanner and nothing changes D:The sketch just waits and waits..I tried all my fingers, three toes, and my brothers fingers. so im pretty sure its not that.Ill also note if you take a look at that manual thing, the two unused pins are "finger detection power" and "finger detection signal output"I can see what these *might* do, but have exausted my troubleshooting skills D:I couldnt figure out how to talk to it without the arduino and the library though, when connected via a USB TTL adapter at 57600 baud I get no replies from the thing :/ and no red light..So what I ask of you readers is has anybody got an idea of something I could try here, or even better, has anybody got one of these working ?Thanks in advance,CountEdit 1:Changed eBay link to normal hyperlinkEdit 2:added edit reason + tl;drEdit 3:adafruit library:https://github.com/adafruit/Adafruit-Fingerprint-Sensor-Library
ebay uv solder mask - Page 1
Forum section: electronics / beginners

author: ME
author_rank: Frequent Contributor
timestamp: June 08, 2025, 09:35:01 pm
content: I brought this uv curable solder maskhttps://www.ebay.co.uk/itm/405462530385, Fitted fresh batterys to the uv torch and after 20 mins under the uv it is still wet/runny , Is that normal?.

author: SuzyC
author_rank: Frequent Contributor
timestamp: June 08, 2025, 09:43:26 pm
content: Propably your uv torch is much too weak to work well.

author: wraper
author_rank: Unknown
timestamp: June 08, 2025, 09:46:23 pm
content: It's a wide spectrum that falls under UV designation. That torch probably has a wrong (too long) light wavelength to provide efficient resin hardening.

author: coppercone2
author_rank: Super Contributor
timestamp: June 08, 2025, 09:54:46 pm
content: Its hard to cure I have a light that makes black plastic smoke when its under neath and its OK to cure that stuff after a while. (365nm)I noticed if you mix pigment and UV resin its very hard to cure. Not sure how much better true dye is, but it must attenuate.I wonder how many of those mixes their selling is DIY solder mask made with UV glue and random powders....btw that shit is aweful to work with, those tubes. I bought a little jar recently maybe its better but I doubt it. All I managed to do is make a giant mess

author: M4trix
author_rank: Frequent Contributor
timestamp: June 08, 2025, 10:32:58 pm
content: Btw, nothing lasts forever. Every UV ink has an expiry date. Keeping it in the fridge can prolong its shelf-life. Now the question is, is your 'UV' light inadequate or the ink has died !?

author: indeterminate
author_rank: Regular Contributor
timestamp: June 08, 2025, 10:33:07 pm
content: It works fine under direct sunlight or a germicidal uv tube.

author: wraper
author_rank: Unknown
timestamp: June 08, 2025, 10:37:45 pm
content: Quote from: indeterminate on June 08, 2025, 10:33:07 pmIME while UV-C lamps do work, curing takes way longer than with 365nm (IIRC) LEDs I bought on ebay many years ago. Also penetration depth is not great with those, so it becomes worse if you want to cure a thicker layer.
Ebers-Moll and how to use it to calculate emitter current. - Page 1
Forum section: electronics / beginners

author: dsharp02
author_rank: Contributor
timestamp: June 29, 2018, 01:02:28 pm
content: I haven't had a lot of time to do any electronics for the past couple of years, so I've been re-reading TAoE. How do you use the Ebers-Moll model to calculate the current for a given Vbe? Wouldn't you have to know Ies? How do you calculate Ies?Sorry if this is a stupid question.Thanks,Dave

author: kosine
author_rank: Regular Contributor
timestamp: June 29, 2018, 02:11:07 pm
content: Don't have my copy of AoE to hand, but I recall the presented model is the simplified approximation, which is based on the idealised Shockley diode equation. Start by understanding that if you're keen to learn more.The reverse saturation current (I_s) is a key parameter, but it can vary by quite a bit between actual transistors, and there are many other factors that affect the operating currents. As a result, Spice software tends to use the Gummel-Poon model to give a better approximation, but that's a bit more complicated. (Looks up "Gummel plot" as well. They're a very good way to understand BJTs. Surprised Dave hasn't done a video on it yet...)If you really want to go down the rabbit hole, I'd suggest getting a copy of "Integrated Electronics: Analog and Digital Circuits and Systems" by Millman and Halkias. Secondhand copies are cheap, and it covers all the theory that Horowitz and Hill gloss over.

author: Wimberleytech
author_rank: Super Contributor
timestamp: June 29, 2018, 05:41:43 pm
content: Quote from: dsharp02 on June 29, 2018, 01:02:28 pm

author: LvW
author_rank: Frequent Contributor
timestamp: June 29, 2018, 07:00:10 pm
content: Yes - Ebers-Moll is the correct relation between Vbe and Ie.However - in practice, it plays no major role.Why not? Because we do not know the value of Is. In addition, the current Is is strongly temperature dependent.So - what to do?The answer is: negative feedback.It is common practice to bias the base with an suitable voltage and to implemet - in addition - negative DC feedback (in most cases we are using an emitter resitor RE).This negative DC feedback remarkably reduces the sensitivity of the whole stage against uncertainties (tolerances) of the active device.In principle, we have the same situation (and we do the same: negative DC feedback) for all opamp stages.
ECAD / EDA Software used by Dave in his Blogs - Page 1
Forum section: electronics / beginners

author: casslan
author_rank: Newbie
timestamp: December 01, 2010, 11:47:03 pm
content: I recently have been catching up on shows, and saw Dave's PCB work on the Watch and Calculator....awesome stuff!!What software does he use?Thanks,Rick

author: Hypernova
author_rank: Unknown
timestamp: December 01, 2010, 11:48:52 pm
content: Altium designerFor example this is what I got:

author: casslan
author_rank: Newbie
timestamp: December 01, 2010, 11:51:08 pm
content: That looks awesome!Thanks btw, I did a search first but didn't find the answer.I'll check it out.Rick
ECG Front end ADS1298 - Page 1
Forum section: electronics / beginners

author: ZeroResistance
author_rank: Frequent Contributor
timestamp: June 13, 2019, 03:26:37 pm
content: Just Trying to Understand an ECG Front end like the ADS1298 here.This is a 8 channel simultaneous sampling Analog Front End for ECG applications.Now the chip can be driven from analog bipolar supplies likeAVdd +2.5VAVss -2.5Vand has an internal reference of 2.4V that is referred to the negative supplyVrefp +2.4VVrefn = Avss = -2.5VThe usable input range of the internal PGA / ADC without saturating is +/- Vref / Gain so if I consider a max gain of 12 we get a range from +200mV to - 208mV.Now I'v attached the characteristics of an ECG signal below.As can be seen the signal of interest is only around 5mV but it is imposed on a dc electrode offset of +/- 300mV and in addition to that a large common mode mains offset of upto 1.5V.My question is, if I DC couple this ECG signal to the inputs of the PGA, how are such large offset voltages not saturating the PGA?Is the high CMRR of the device (-115 dB) taking care of these offsets.

author: RandallMcRee
author_rank: Frequent Contributor
timestamp: June 13, 2019, 04:20:08 pm
content: Yes, but the CMRR is only applicable over the CM range, so in the datasheet is needed to see this:

author: ZeroResistance
author_rank: Frequent Contributor
timestamp: June 14, 2019, 04:18:21 am
content: Quote from: RandallMcRee on June 13, 2019, 04:20:08 pmBut I guess the offset also gets "Multiplied" by gain if its dc coupled, so a offset of 0.1V with a gain of 6 will appear as 0.6V at the output of the PGA. AFAIK in dc coupled system there is no way to remove this offset unless of course a circuit is built to tackle it. The offset is allowed to passthru the PGA stage and the ADC stage and only remove using digital filters in firmware.Please correct me if I'm wrong.
EDA should I choice ? - Page 1
Forum section: electronics / beginners

author: saeed.GH
author_rank: Newbie
timestamp: September 07, 2017, 07:14:12 am
content: HiI like starting pcb design and Idont know what software is good for start ? why ?

author: krystian
author_rank: Contributor
timestamp: September 07, 2017, 07:29:42 am
content: DipTrace. Simple and easy to use but not many features are available. For hobbyist use its the best.

author: RoGeorge
author_rank: Super Contributor
timestamp: September 07, 2017, 07:46:44 am
content: KiCAD, if you like free, open source and capable to work offline.

author: Fire Doger
author_rank: Regular Contributor
timestamp: September 07, 2017, 07:54:22 am
content: Any program is good to start. After a while you will find whats the best for you.All famous EDA work similar, on all of them you have to learn their shortcuts.I would suggest eagle because you can find a ton of examples, tutorials etc to understand how EDA works. After a couple of months check others and choose. The hard part is to learn how to layout a pcb, not to use the program.

author: Brumby
author_rank: Unknown
timestamp: September 07, 2017, 09:07:07 am
content: Quote from: RoGeorge on September 07, 2017, 07:46:44 amI like that sort of thing - which is why I installed KiCAD on my computer.From the time I started the download to viewing a 3D model of an astable multivibrator board using discrete components was something like 1 hour. First effort - and there's a lot that could be improved - but it would have worked.
Eddy currents / Metal Detectors - Page 1
Forum section: electronics / beginners

author: ElectMan
author_rank: Newbie
timestamp: August 07, 2012, 06:56:14 pm
content: Hello everyone. I've just entered this forum, so I'm new here. I'am interested in knowing some basic info on metal detectors and basic principles, like the eddy currents. Can't seem to find this anywhere.First thing:When and oscilating current is passed trough a coil, in the presence of a metal, how is this oscilation affected? In frequency, phase, amplitud? I'm expecting frequency, but heard some stuff about phase.

author: mariush
author_rank: Super Contributor
timestamp: August 07, 2012, 08:12:57 pm
content: May I suggest reading up on some of the patents around metal detectors? They're usually quite informativehttp://www.google.com/?tbm=pts&hl=en#hl=en&tbm=pts&sclient=psy-ab&q=metal+detector&oq=metal+detector&gs_l=hp.3..0l4.0.0.1.16.0.0.0.0.0.0.0.0..0.0...0.0...1c.cAaK96Incl4&pbx=1&bav=on.2,or.r_gc.r_pw.r_qf.&fp=956604e6f44a6451&biw=1920&bih=932Another simple search "google detector do it yourself" reveals these pages with a lot of info*http://www.easytreasure.co.uk/bfo.htm*http://www.instructables.com/id/Home-Made-BFO-metal-detector/*http://nevada-outback-gems.com/design_plans/DIY_metal_detect/metal_detector.htm

author: ElectMan
author_rank: Newbie
timestamp: August 08, 2012, 10:59:32 am
content: Thanks. That info helped. Eddy currents do affect signals on frequency.
Edge connector current rating - Page 1
Forum section: electronics / beginners

author: nemo000111
author_rank: Contributor
timestamp: October 07, 2013, 05:52:00 pm
content: Hi All,How do you determine the maximum ammount of current that can flow safely though a pcb edge connector pin and how many pins are needed to safely use a given amperage? I've got a project that needs 2 30a rails at 12v each. I've got several server power supplies that output 12v at 800W. They have a 64 pin edge connector with 2 20 pin 12v connector tabs and 2 20 pin ground connector tabs (tabs being a continous conductor instead of 20 individual ones). The balance are signal and small 3.3v and 5v rails. I take each of the 2 12v tabs and make that a rail, however I don't know if the pcb edge connector will be able the handle it. I know the tabs on the power supply can handle this, I'm just not sure of the edge connector I'd need to put on a pcb. Thanks.

author: Smokey
author_rank: Super Contributor
timestamp: October 07, 2013, 09:36:14 pm
content: The PCB track width for a given current (and plating thickness) is easy to calculate. The contact current of the mating connector is the thing you need to worry about. Check the data sheet for whatever mating connector you will be using. It should say what the current rating.

author: nemo000111
author_rank: Contributor
timestamp: October 08, 2013, 02:31:09 am
content: So far the datasheets I've found haven't listed the the electrical specs. It lists the physical dimensions and the metal, plating, and size of the contacts. Is there a rule of thumb for edge connector contacts?

author: walshms
author_rank: Regular Contributor
timestamp: October 08, 2013, 03:07:12 am
content: 1.1A per pin in a PCI-E edge connector per the standard.

author: nemo000111
author_rank: Contributor
timestamp: October 09, 2013, 09:37:55 pm
content: Thanks much. That's what I thought it. Do I need to do anything special if I need more current than 1 pin can provide? Is the equation linear, i.e 5A would be 5 pins on the same trace of the correct thickness?

author: walshms
author_rank: Regular Contributor
timestamp: October 09, 2013, 10:02:30 pm
content: Yes, provided you have sufficient trace thickness. They should be joined outside of the connector, but you could do that.Just be sure that the system you're plugging into supports that current load via the connector -- while the specification allows for it, not everything is designed for it.
Edge Sensitive Schmitt Trigger? - Page 1
Forum section: electronics / beginners

author: slowaudio
author_rank: Contributor
timestamp: January 14, 2014, 04:07:34 pm
content: Hey everyone. This is my first post, so apologies if I'm doing this wrong.What I'm looking to make, for a lack of better terms, is an edge sensitive Schmitt Trigger. Essentially, what I'd like to do is create some sort of transition at an edge (perhaps from VDD -> GND) and keep that state until an edge hasn't been detected for some period of time.I've tried Googling a few different things, but haven't come up with anything useful, as of yet. I'd appreciate any help.Thank you.

author: filip_cro
author_rank: Regular Contributor
timestamp: January 14, 2014, 04:18:12 pm
content: So you want to make edge detector? Or you want it to also have hysteresis? How? Please make basic waveform drawing for input and output.

author: Rufus
author_rank: Super Contributor
timestamp: January 14, 2014, 04:28:18 pm
content: You are probably looking for a re-triggerable monostable.

author: Marco
author_rank: Super Contributor
timestamp: January 14, 2014, 04:31:29 pm
content: There is a name for the circuit you describe, it's called a retriggerable monostable multivibrator (last term sometimes omitted). You can buy them as ICs, circuits using 555 or D-flip flops implementing it are also easy to find.

author: slowaudio
author_rank: Contributor
timestamp: January 14, 2014, 05:22:38 pm
content: Quote from: Rufus on January 14, 2014, 04:28:18 pmAfter a quick inspection, it appears this is exactly what I was looking for! I'm just a EE student, so I'm still learning, I really do appreciate it.I knew I had come to the right place, thanks guys!

author: zapta
author_rank: Super Contributor
timestamp: January 14, 2014, 11:00:37 pm
content: Does this help?http://www.nxp.com/documents/data_sheet/74HC_HCT123.pdf
Edison TechCenter Universe of Instrumentation Program - Page 1
Forum section: electronics / beginners

author: Unknown
author_rank: Unknown
timestamp: November 10, 2015, 07:30:26 pm
content: You guys have probably seen this but I thought it worth sharing:http://www.edisontechcenter.org/Instruments.htmlEdison TechCenter are doing a Universe of Instrumentation Program which looks to be really interesting!
Edit pad in Eagle CAD  - Page 1
Forum section: electronics / beginners

author: peps1
author_rank: Regular Contributor
timestamp: August 13, 2014, 04:05:49 pm
content: Is there a quick way to change pad size in the board editor, without having to go into library and edit each of the part permanently?

author: RiverTown
author_rank: Regular Contributor
timestamp: August 13, 2014, 04:25:36 pm
content: Unfortunately no.If you working on diy board which you will etch yourself, than you can cheat by setting grid on finest, and then placing via on pad.You can't ordinarily do this, but you will get the error only when you hit exact spot, and that is very difficult.

author: peps1
author_rank: Regular Contributor
timestamp: August 13, 2014, 08:38:27 pm
content: That's a shame, have a bunch of boards I want to send of to be made, but the pads are just a little to small for me to build on them quickly!But, that via pad trick is handy for the board I etch at home.

author: ThomasDK
author_rank: Regular Contributor
timestamp: August 14, 2014, 05:17:09 pm
content: You can tweak the min. pad sizes in DRC.Note: This will affect all pads on your board, check your clearances afterwards!Edit:http://www.instructables.com/id/Make-hobbyist-PCBs-with-professional-CAD-tools-by-/step9/Changing-pad-sizes-with-the-RESTRING-rules/

author: peps1
author_rank: Regular Contributor
timestamp: August 14, 2014, 11:33:05 pm
content: Thank you so much, that is such a handy trick!
Education or training - almost free! - Page 1
Forum section: electronics / beginners

author: OhmSweetOhm
author_rank: Newbie
timestamp: January 02, 2014, 05:51:27 pm
content: Saw this from edX - looks interesting:https://mktg.edx.org/course/utaustinx/utaustinx-ut-6-01x-embedded-systems-1172?utm_source=edX+Course+Announcements+Mailing+List&utm_campaign=3cc08328e4-Student_Newsletter_December_30_2013_D_12_30_2013&utm_medium=email&utm_term=0_237694b56d-3cc08328e4-30840589I hope someone finds this useful!

author: mtdoc
author_rank: Super Contributor
timestamp: January 02, 2014, 07:25:30 pm
content: Looks good. I think I'll audit it. Thanks!

author: newbie666
author_rank: Regular Contributor
timestamp: January 02, 2014, 09:22:27 pm
content: Signed up for the course! Thanks for the link, I would have missed it
edX: 6.002X Circuits and Electronics is running again starting 1/20/2015 - Page 1
Forum section: electronics / beginners

author: orin
author_rank: Frequent Contributor
timestamp: January 16, 2015, 04:06:18 am
content: I did it a couple of years again. It is well worth the effort to learn or review the fundamentals. The prof has a bias towards MOSFETs. You'll not find much on regular transistors or FETs. Probably the right choice given the length of the course. Your algebra skills need to be fairly good, and ideally, you need some calculus. It is after all, a college level course.www.edx.orgSearch for 6.002xThey say 12 hours/week estimated - probably a little high if you have the pre-requisites. Don't worry about the mention of Maxwell's equations early on - they are immediately abandoned in favor of the lumped circuit abstraction.

author: MacAttak
author_rank: Unknown
timestamp: January 18, 2015, 03:27:01 am
content: This will be my third time trying to complete it. On the previous two attempts I ended up getting swamped with work / travel midway through and couldn't keep up.Looking forward to seeing him light up yet another pickle.

author: juanfermed
author_rank: Regular Contributor
timestamp: January 18, 2015, 10:59:26 pm
content: Really good course, the better college course I have received, and it was online!
edX Realtime Bluetooth Networks Shape the World is now online  - Page 1
Forum section: electronics / beginners

author: JacquesBBB
author_rank: Frequent Contributor
timestamp: September 16, 2016, 07:11:29 am
content: The edX course Realtime Bluetooth Networks Shape the World is now onlinehttps://www.edx.org/course/real-time-bluetooth-networks-shape-world-utaustinx-ut-rtbn-12-01xLooks very nice and is concentrated on the development of a Real Time Operating System (RTOS) forTi launchpad board.Bluetooth only appears in the last lab.The module for the courseBOOSTXL-EDUMKII which is now bundled with the MSP-EXP432P401R board (also for the course) for 39.99$with free shipping (for the moment )https://store.ti.com/msp-bndl-p401redu.aspx

author: made2hack
author_rank: Frequent Contributor
timestamp: September 20, 2016, 03:54:26 pm
content: Good thing that I bought the Boost for 45$ separately and the MSP432 for 12$, since I hate saving money
EE-ATX Standard - Mounting holes - Page 1
Forum section: electronics / beginners

author: wishgranter
author_rank: Newbie
timestamp: October 12, 2012, 11:09:56 am
content: Hello All. Im searching for some documentation regards the EE-ATX Motheboard format. Im buing a Dual XEON board and need litle correction to by EATX/BTX PC case that im can put there... is a SUPERMICRO motheboard size.....Cannot find ANY hint about mounting holes or something similar that can give me clue where im should make my holes in that case....EEATX (enhanced extended ATX) 13.68 in (347 mm) 13 in (330 mm)http://en.wikipedia.org/wiki/ATX

author: Unknown
author_rank: Unknown
timestamp: October 12, 2012, 01:14:22 pm
content: Same as ATX holes basically.http://www.formfactors.org/developer%5Cspecs%5Catx2_2.pdfCheck above document page 10.Holes A G and K are the extra holes used for EATX, detailed dimensions on the following pages.

author: wishgranter
author_rank: Newbie
timestamp: October 12, 2012, 02:22:29 pm
content: Hmm Thanx, but you mention EATX and im need EEATX that have dimension 13.68 in (347 mm) 13 in (330 mm)the EATX has just 12 in (305 mm) 13 in (330 mm).... OK will try something with it...

author: petreza
author_rank: Contributor
timestamp: January 31, 2015, 07:17:26 pm
content: Quote from: wishgranter on October 12, 2012, 02:22:29 pmHi wishgranter,Were you able to find any info on the EE-ATX mounting holes standard? Were you able to modify your case to accommodate EE-ATX motherboard?Thanks!
EE Internship - Page 1
Forum section: electronics / beginners

author: Fantasma25
author_rank: Regular Contributor
timestamp: December 17, 2013, 04:04:44 am
content: Hello. I am on my third year of college and I'm trying to get a summer EE internship in another country (particularly in the UK). Has anybody made an international internship before? Any advices or experiences to share?

author: free_electron
author_rank: Super Contributor
timestamp: December 17, 2013, 07:02:40 am
content: i did. contact IAESTEhttp://www.iaeste.orgi did mine through them for 3 years at Nokia in finland ( 1989 to 1991 ).sigh. i'm getting old.. thats 22 years ago ...

author: Fantasma25
author_rank: Regular Contributor
timestamp: December 17, 2013, 02:56:05 pm
content: Wow! That's really cool! How was it? Did you have to learn finnish?

author: free_electron
author_rank: Super Contributor
timestamp: December 17, 2013, 03:41:32 pm
content: Tervetuola and huva paivaa is about how far i got.Uksi kaksi kolme nelja vies hex seitseman, ottaman is counting... I forgot what 9 is...Nah, english is universal, even in star-trekIAESTE is a great organisation. They file your work permit, arrange lodging with a local family , organise meet-and-greet. I was paid like a normal worker and they covered my plane ticket.It is a great experience working abroad.

author: Fantasma25
author_rank: Regular Contributor
timestamp: December 17, 2013, 03:56:21 pm
content: That must have been an awesome experience! What did you get to do at Nokia?

author: SeanB
author_rank: Super Contributor
timestamp: December 17, 2013, 06:21:36 pm
content: http://www.theamphour.com/169-an-interview-with-vincent-himpe-escaped-electron-elocution/All you need to know, in a very relaxed and interesting interview.

author: Fantasma25
author_rank: Regular Contributor
timestamp: December 17, 2013, 07:37:20 pm
content: Thank you! That is very interesting
EE Student with some questions - Page 1
Forum section: electronics / beginners

author: lasmori
author_rank: Contributor
timestamp: May 06, 2015, 03:22:39 pm
content: Hi folks! I am a college student working on an EE degree and have decided it's time to ask a few questions.I have a grant paying my tuition each quarter and it provides me with a little bit of money after paying a couple bills. I would really love to use this for obtaining some lab equipment. If I were to buy some equipment off ebay or another online auction... what should I be looking for? What should I be careful about? I live in a remote/small city and have not had a much luck at my local auctions (Hoquiam, WA US).Engineering licensing in Washington requires 4 years of internship under a licensed Engineer. Do I have to be working a certain number of hours? What are a few good ways of finding an Engineer to intern under? It's especially important the internship be compatible with a school schedule. I am likely transferring to Western Washington University (Bellingham, WA) around 2017 and hope to find an internship in that area during that time.I have worked in the software development field for a number of years now. My life made a downhill turn resulting in homelessness until a little over a year ago. Things have been going way better this past year and I have decided to use this as a pivot point for my life. This is my first time in college and I am very much loving it so far! Electronics has been a long term interest of mine and I am pretty excited about changing careers.Thanks for answering my questions!Lori

author: edavid
author_rank: Super Contributor
timestamp: May 06, 2015, 03:33:41 pm
content: Quote from: lasmori on May 06, 2015, 03:22:39 pmVisit your local ham radio club and ask that question:http://www.gharc.org/People will probably be happy to give/sell/loan you equipment to get you started.QuoteWhy do you think you want to be a PE? Very few EEs are, for good reasons.

author: lasmori
author_rank: Contributor
timestamp: May 06, 2015, 03:47:15 pm
content: Quote from: edavid on May 06, 2015, 03:33:41 pmI will do that! I met someone in this club last quarter... didn't occur to me to ask them some questions in this regard! I used to have a license myself a few years ago and had been thinking of attending their club.Quote from: edavid on May 06, 2015, 03:33:41 pmThat is a very good question. I had assumed this was the standard route one eventually goes down with Engineering.
EE Toolkit PRO App - Page 1
Forum section: electronics / beginners

author: rstofer
author_rank: Super Contributor
timestamp: February 07, 2022, 03:59:41 pm
content: I bought the PRO version of EE Toolkit for my iPad a couple of years ago. I didn't really spend much time with it. Fast forward, I was bored yesterday and decided to play with it. It's pretty amazing!This app has a tremendous amount of information - pinouts for Arduino, RPI and a bunch of others, calculators for all those pesky equations like delta-wye and voltage divider. Of course the 555 configurations can be evaluated along with a host of other things. Transistor amplifier configuration tools. And on and on...I realize this app was discussed briefly late last year and back in 2018 but it was only tangential. This toolkit is VERY useful, I should have looked sooner.The PRO version is $3 around here and there is a more limited free version. Here is a link to the mother ship. You can get the app from your app store.https://ee-toolkit.com/Many of our discussions re: theory are covered by this app. It packs a lot of information in a single location. I prefer to use it on an iPad simply due to screen size (old eyes).Give the free version a try and see what you think!

author: HobGoblyn
author_rank: Unknown
timestamp: February 07, 2022, 10:49:06 pm
content: I’ve had the pro version for about a year (I also use on my iPad rather than phone). A lot of useful info on there
EE40LX - Edx.org Electronic Interfaces course - Study group - Page 1
Forum section: electronics / beginners

author: MCRodrigues
author_rank: Contributor
timestamp: January 06, 2015, 09:43:55 pm
content: Hello everyone, my first post on this forum!!Since I don't have anyone interested on electronics near me, i'm trying to get a study group for the course at Edx.org, EE40LX - Electronic Interfaces: Bridging the Physical and Digital Worlds. I would like to know if anyone is interested also in this course.https://www.edx.org/course/electronic-interfaces-bridging-physical-uc-berkeleyx-ee40lx#.VKxSlSusVjYBest regards!

author: CrashBang
author_rank: Contributor
timestamp: January 07, 2015, 07:12:49 pm
content: Hi. I've also registered. In the past I've found edX often have forums that allow you to hook up with fellow students. You might even find someone close to you...

author: MCRodrigues
author_rank: Contributor
timestamp: January 08, 2015, 10:03:52 pm
content: Well when I made the UT6.01x Emdedded systems course I had a small workgroup at school. But now, with computer engineering bachelor almost made and getting ready for the internship, the group got faded away. Everyone else aren't interested on the topic anymore... So i'm by myself now. Anyway, worth to try.I've been checking the list of parts required of the course, and some of them are not available on mouser.com, specially the op amps. Do you know where i could get those components on Europe?

author: miguelvp
author_rank: Super Contributor
timestamp: January 09, 2015, 06:40:50 am
content: usewww.octopart.comthey usually list EU suppliers,www.findchips.comwill list EU suppliers as well as far as I know

author: ElektroQuark
author_rank: Unknown
timestamp: January 09, 2015, 07:47:05 am
content: Find the MCP602 op-amp. You can use that too.

author: MCRodrigues
author_rank: Contributor
timestamp: January 09, 2015, 01:47:44 pm
content: I'll check both. Thanks .
EEPROM Not working - Page 1
Forum section: electronics / beginners

author: Sai Shoby
author_rank: Newbie
timestamp: November 13, 2020, 01:17:43 am
content: Hi all,i want to read and write the internal eeprom memory of 18f25k80Whenever i add eeprom_write line, the program struct and not working. Please help me find the problemhere i attached my basic testing code. i am using mikro c pro compliervoid main(){I2C1_Init(100000);LCD_Begin(0x74);EEPROM_Write(0x01,1); // Works without this line, when i add this line doeLCD_Goto(3,1);LCD_Print("Hi");}

author: battlecoder
author_rank: Regular Contributor
timestamp: November 13, 2020, 02:25:57 am
content: I haven't used that particular compiler, but what version of the mikro C compiler are you using?There's apost in the mikroe forums, from 2018, where someone had the same problem, and "fixed" it by downgrading to an earlier version of the compiler.
EEPROM programming - "Verify after" fail - Page 1
Forum section: electronics / beginners

author: IvoS
author_rank: Frequent Contributor
timestamp: August 26, 2013, 09:30:49 pm
content: I am trying to make a clone out of my EPROM (Signetics 27C64 from CDPlayer) using this universal programmerThere is't exactly this EPROM type in this programmer database, but I can read the chip selecting Fujitsu, ST, etc., which should be OK.?Once I have the hex data I am trying to program it to Atmel 28C64 EEPROM but the chip always fails the "verify after" process at the end. When I read from this newly programmed EEPROM I can see that written file doesn't correspond to the original EPROM file. Therefore the "verify after" fail I guess. How can I program this properly?

author: IvoS
author_rank: Frequent Contributor
timestamp: August 26, 2013, 09:55:43 pm
content: Never mind, I figured it out....my mistake.

author: fluxcapacitor
author_rank: Frequent Contributor
timestamp: August 26, 2013, 10:25:57 pm
content: how did you sort it, was it the device ID .
EEPROM  - Page 1
Forum section: electronics / beginners

author: Jane
author_rank: Frequent Contributor
timestamp: November 02, 2023, 08:36:50 pm
content: Is it common that a byte in an EEPROM can be changed during using it in an equipment?

author: ataradov
author_rank: Super Contributor
timestamp: November 02, 2023, 08:47:37 pm
content: You mean a change on its own without an external write? No, this is not common.You can sometimes see some degradation in very old equipment (like from the 80s). But with more modern devices it basically never happens.

author: wraper
author_rank: Unknown
timestamp: November 02, 2023, 08:53:30 pm
content: Question rather seems to be about normal use. EEPROM is generally used to store settings or something like that. So it's contents will change during normal device operation. Although there are some uses when data does not change, like EDID EEPROM in monitors or storing serial number and config in say USB/RS232 adapters.

author: janoc
author_rank: Super Contributor
timestamp: November 02, 2023, 08:54:27 pm
content: Quote from: Jane on November 02, 2023, 08:36:50 pmCan it be changed? Sure. Just write into it.Whether that's expected or normal for the equipment is impossible to say without knowing how that equipment in question functions. But given that EEPROMs are usually used to store configuration or user settings, they tend to be written to as well, kinda by definition.

author: CaptDon
author_rank: Super Contributor
timestamp: November 02, 2023, 10:36:52 pm
content: Their very function in many cases is 'non-volatile ram' and as such they can be changed often. They have data retention for something like 100 years for the newer stuff and maybe 20 years for the older dies. HOWEVER, there is a finite number of write cycles to any specified location. This can be as few as 10,000 and often specified at 100,000 so one must be careful about how often a particular location is written to. Case in point, we had some old video terminals that stored parameters in a very early version of eeprom, one with a couple hundred write cycles max. We found that with age the eeprom was no longer 'non-volatile' and with a power outage the settings would become corrupted. When the terminals were new they could survive power cycling without corruption.
Eeschema - visualize label connections? - Page 1
Forum section: electronics / beginners

author: Codealot
author_rank: Newbie
timestamp: December 03, 2019, 08:34:34 pm
content: Is there any way to visualize all the connections between matching labels on the sheet?

author: jhpadjustable
author_rank: Frequent Contributor
timestamp: December 03, 2019, 11:58:10 pm
content: Select the highlight net tool, squiggly purple line icon in the right-hand toolbar, then click on a wire.

author: Codealot
author_rank: Newbie
timestamp: December 04, 2019, 05:04:22 pm
content: Quote from: jhpadjustable on December 03, 2019, 11:58:10 pmAny way to do this for all the labels on the sheet?

author: jhpadjustable
author_rank: Frequent Contributor
timestamp: December 04, 2019, 06:03:47 pm
content: Oh, I see now. You want a ratsnest on the schematic. Not that I know of. Better to draft the schematic for readability without tools.
eev-esque constant current dummy load. - Page 1
Forum section: electronics / beginners

author: dda
author_rank: Contributor
timestamp: August 18, 2012, 07:38:05 am
content: Hey,I decided to have a go at making a constant current dummy load as seen on eevblog #whatever.I decided I would try to power it from a 3V coin cell, and the op-amp i had laying around was a lm348n. The non-inverting input is 0-1.5V obtained through a pot/voltage divider. Ideally I would have a 0V to 1.something V constant current load.Now the problems.Using 3V as Vcc doesnt allow the voltage to change as the non interting input is altered.Powering from 9V works, but the lowest output is 0.6V(i.e, A), Id want it lower. <~100mA ideally.Obviously the op-amp I had laying around (lm348) isnt suited for this application.So... Is there a better op-amp to choose. is a lm324 (as dave used) going to work better? What value on the data-sheet do I need to be looking at to meet my objectives?Any suggestions would help

author: Rerouter
author_rank: Super Contributor
timestamp: August 18, 2012, 08:07:46 am
content: what you want is an op amp with a common mode input and output range including the negative rail (generally listed in the fist page of schematics)as your signal level is 0-1V its very easy, just make sure your input range is better than vcc-2V, generally this means only 1.5V Maximum on the really cheapy ones so it shouldnt be an issue, for the input,however for the output level, you run into an issue, if your aiming to make the circuit as simple as possible with a 1 Ohm measuring resistor so the signal levels match, then a vcc-1.5 wont cut it, and you will have to spend a few more cents, as at 1A your resistor is at 1V, when you add on the base-emmittor junction of the resistor this comes to 1.75V which is higher than the cheapy can handle,short version: an op amp with an input range of 0-greater than 1, and an output range of 0 to greater than 2, those are the specs you want to make it work,
EEV #??? where cool old guy built a homemade RF Sprectrum Analyzer - Page 1
Forum section: electronics / beginners

author: lordvader88
author_rank: Frequent Contributor
timestamp: March 24, 2017, 10:32:34 am
content: That looked really cool. Thats a type of project I want to save up for the right parts, and study enough to understand how it all works.Does that cool old guy have a schematic ?? I briefly searched google once, for spectrum analyzer schematic, and who knows what I found.Can some one please point me to older fashion types schematics that someone could build with today's discrete components, but using basic discrete parts.So more like someone in the 70s might have made at home

author: lordvader88
author_rank: Frequent Contributor
timestamp: March 24, 2017, 10:35:05 am
content: Dave you went to a gathering of some sort, of folks with electronics stuff, and one cool old guy had a type of homemade spectrum analyzer. Thats the EEV show I refer to

author: EEVblog
author_rank: Unknown
timestamp: March 24, 2017, 01:08:46 pm
content: Just type "eevblog spectrum analyser" into youtube
EEVBlog 121GW Shows Incorrect Negative DC Voltage Polarity in Auto DC+AC Mode - Page 1
Forum section: electronics / beginners

author: postfive
author_rank: Contributor
timestamp: February 07, 2023, 04:16:11 am
content: I just noticed when measuring some negative DC voltages while the 121GW meter was in the Auto DC + AC mode that the polarity does not show a minus sign; it stays at a positive sign regardless of the voltage polarity being measured. When the meter is switched to DC only mode, it works fine. My meter had 1.04 version firmware and I figured maybe the latest firmware update would fix this so I just downloaded and installed Version 1.05, but it still shows the same incorrect polarity indicator. Wondering if this is a feature (since in AC mode, there is no polarity, so maybe in the Auto DC + AC mode the meter is forced to ignore polarity) or whether this is an actual bug and if so whether a new version of the firmware could be released to fix this. It isn't that much of a big deal, but unless you look closely at the mode display you could be led down the garden path by the false polarity indication.

author: bdunham7
author_rank: Super Contributor
timestamp: February 07, 2023, 04:36:54 am
content: You're right, that is an error. Typically TRMS AC+DC indications leave out the polarity, but theoretically you could have a polarity sign that reacts to the DC part. However, it would be weird if you had a pure AC signal which would give you a non-zero reading but no polarity. In addition, the way TRMS AC+DC is typically done--with a TRMS converter chip--the meter won't even know the polarity unless there is a separate DC circuit. In any case, if it gave you the correct polarity, it would be unusual. Giving you the wrong polarity is...wrong. Report it, perhaps they'll fix it, it's just a matter of disabling the polarity indicator totally in that mode.
EEVBlog: #212: Personal Advice - Page 1
Forum section: electronics / beginners

author: codemonkeyrawks
author_rank: Contributor
timestamp: March 04, 2018, 11:07:03 pm
content: Hi There,In relation to eevblog video:I am looking at perhaps building (resistor decade box) for myself - I am curious what might be the best brand of resistors to use or purchase that are high quality.I am looking at perhaps building a (capacitance box) for myself - I am curious what might be the best capacitors to use or purchase that are high quality.Just a couple of things I might add to my toolbox.

author: Brumby
author_rank: Unknown
timestamp: March 05, 2018, 12:28:29 am
content: Quote from: wilfred on March 04, 2018, 11:27:39 pmIf you haven't used a substitution box much - you are bound to make this error a couple of times in the beginning ... and the odd time later on.I will leave you to think about how that could happen. Working out the answer for yourself will give you an understanding that simply telling you will not.

author: codemonkeyrawks
author_rank: Contributor
timestamp: March 06, 2018, 04:14:15 am
content: I think I will see if Digikey has some resistors and caps from Vishay that are 1/2W 1% and will work from that (ideally just looking for a brand). I have a small lab (PS, F-Gen, Scope, DMM) and not much ind. components (so it be nice to breadboard out ahead of time along with using this) before I purchase stuff and do some troubleshooting as well.I don't see me working on high tech gear in this lab
EEVBlog #221 power supply build. - Page 1
Forum section: electronics / beginners

author: Beamin
author_rank: Super Contributor
timestamp: July 20, 2018, 07:52:03 pm
content: So after watching this video: Why doesn't the load resistor he uses on it get super hot when it's connected up in constant voltage mode? I tried this a while ago and thought I burned up or burned myself on the resistor when I tried this. Can't that part put out an amp (5W) or so? Or does he have his supply CC limited? I shorted mine by accident and the LM part got hot enough to melt plastic before I shut it off. It still works though that's a durable part was shorted for a while before I noticed the smell of burning.Is it possible to build the LM out of discrete parts or does it contain things like those transistors with multiple legs that you can't simulate or other exotic parts like temp regulated resistors inside?

author: Beamin
author_rank: Super Contributor
timestamp: July 20, 2018, 11:19:33 pm
content: How does the LT3080 know you are trying to control current and voltage off the same pin?

author: Kleinstein
author_rank: Super Contributor
timestamp: July 21, 2018, 09:57:35 am
content: The LT3080 like most other voltage regulators normally controls the voltage. It is only if the current exceeds a certain limit (around 1.1 A for the LT3080) that the chip changes to current control. This similar to a lab supply - it is either the voltage or current control active to keep the output at the boundary of the set voltage or current. It is the load that decides which control is needed.It is possible to build a voltage/current regulator from discrete parts. There are no magic parts inside that are essential. One may not be able to directly copy the circuit because of such odd parts like multi-emitter transistors and some parts like current mirrors don't work as good. However discrete resistors are generally better than on chip ones and one has larger caps available - so discrete circuits usually look different.Simulation is possible anyway, if one gets the right models. Essentially all modern analog chips are simulated before making them from silicone.

author: Beamin
author_rank: Super Contributor
timestamp: July 23, 2018, 03:04:22 am
content: Quote from: Kleinstein on July 21, 2018, 09:57:35 amWhat I don't understand is he can adjust the current and not just have it max out at 1amp. As far as the part knows it is just seeing a change in voltage at the input pin. Why doesn't the second part just change the voltage fed to it like the first one?And how do those resistors not get super hot at 10ohms or what ever low value it was?
EEVblog #279 – How NOT To Blow Up Your Oscilloscope- QUERY - Page 1
Forum section: electronics / beginners

author: MS1988
author_rank: Newbie
timestamp: January 13, 2025, 01:01:37 am
content: Dear Members,I am beginner and hobbyist. I watched a very educational video below and was not able to figure out at one point how a complete circuit is formed.https://youtu.be/xaELqAo4kkQ?si=QOlH0zAgsvhZJFHRIn the video above I have a question, At 12:18 , how a complete current path is formed when we only connect the alligator clip of probe to positive terminal of widget. I can see from positive terminal current goes through alligator clip to earth circuit and back to widget through negative terminal. How the negative terminal is shorted to positive terminal if only the positive is connected through alligator clip of the probe.New update: After drawing the simplified version of circuit in paper it make sense it's a dead short. Please let me know if my attached circuit and current path is correct when we connect the alligator clip to positive terminal of widget. Please also let me know is what exactly conveyed in the video.

author: Grandchuck
author_rank: Super Contributor
timestamp: January 13, 2025, 07:53:01 pm
content: Yes your arrows trace the short circuit.

author: MS1988
author_rank: Newbie
timestamp: January 13, 2025, 08:07:09 pm
content: Thanks for your reply.

author: wasedadoc
author_rank: Super Contributor
timestamp: January 13, 2025, 08:09:05 pm
content: Better to term the scope probe lead as such or as a "cable", not a "wire". A wire is conventionally thought of as a single conductor. (Even though it may have many strands not insulated from each other.)
EEVblog #490 - Peak Detector Circuit - Queries - Page 1
Forum section: electronics / beginners

author: 2X
author_rank: Frequent Contributor
timestamp: August 09, 2017, 01:33:10 am
content: Hi guys,I saw many times the video "EEVblog #490 - Peak Detector Circuit" where Dave explains the "Peak Detector Circuit" and I can't understand two things. First of all why the capacitor's output (blue waveform) follows the input voltage (yellow waveform) while the operational amplifier's output is negative (Picture 1)? Second this reverse peak (picture 2) is due to the parasitic capacitance of the diode? Thanks!https://youtu.be/jllsqRWhjGM?t=1574https://youtu.be/jllsqRWhjGM?t=1556

author: rs20
author_rank: Super Contributor
timestamp: August 09, 2017, 03:33:31 am
content: 1. Could be parasitic capacitance in the diode,2. Could be either parasitic capacitance in the diode, or the diode could be experiencing a long turn-off time, or both.
EEVblog Android Application for forum - Page 1
Forum section: electronics / beginners

author: Kedar264
author_rank: Regular Contributor
timestamp: February 14, 2015, 09:54:40 am
content: Hi,EveryoneHere's app for eevblog forum and youtube channel ,using the forum and watching eevblog is now easier with this applicationDownload app hereplease share your thughts for futher improvements.https://www.mediafire.com/?si0crlkw7oju4ib

author: miguelvp
author_rank: Super Contributor
timestamp: February 14, 2015, 07:51:54 pm
content: We already seen the other two threads and a third post on the electronics apps thread.No reason to make more threads, you can always comment on the first one you started and maybe add pictures or something.