hybridfree/eevblog-posts huggingface dataset:
Foolproof but basic control of Electromagnet? - Page 1
Forum section: electronics / projects

author: dav888
author_rank: Regular Contributor
timestamp: June 21, 2021, 07:36:57 pm
content: Hi,Looking to control a small "opposite" holding electromagnet.Most common voltage of these seems to be 12VDC, with about 400mA to release the field.Ran across this board that just uses a basic mosfet + gpio control.https://wiki.seeedstudio.com/Grove-Electromagnet/Since available power might be limited and the pulse needed to release the magnet is fairly short, I'd like to find a more foolproof circuit that- has a fixed pulse-length (tuned with R/C)- current limited or clamp with safety-off- soft ramp-control (to be nice to the rest of the system)Anyone with experience using similar magnets and a discreet or 'ready-made IC' (that isn't for 50W solenoids) that can do the job?

author: ledtester
author_rank: Super Contributor
timestamp: June 22, 2021, 01:57:51 am
content: I have one of those 12V P20/15 electromagnets -- just the bare magnet, not the module.For what it's worth, inductance is about 45 mH, resistance 50R giving a time constant L/R of roughly 1 ms.

author: NiHaoMike
author_rank: Super Contributor
timestamp: June 22, 2021, 03:17:03 am
content: Use the transistor switching the low side with a diode across the coil configuration but add a capacitor between the microcontroller and transistor so that a stuck high won't leave the coil energized.
Foot Switch Operated Vacuum Pick n Place - Page 1
Forum section: electronics / projects

author: CoolNamesAllTaken
author_rank: Contributor
timestamp: July 22, 2021, 06:19:59 pm
content: Hi All,Figured I would share my build from a while back for a foot pedal operated vacuum pick and place. It's been working better for me than many off the shelf solutions, primarily due to the foot switch and vacuum design (it includes a dedicated solenoid for venting the vacuum line). Open to feedback for improvements, and if anyone decides to build one, I'd love to see it!https://github.com/CoolNamesAllTaken/vacuum-pickup-tool

author: jesuscf
author_rank: Frequent Contributor
timestamp: July 25, 2021, 08:56:55 pm
content: Interesting how we basically have the same solution for this problem. In the picture below I didn't add the foot switch yet, but it is in parallel with the white push button. I made my pick-up tool controllable via the serial port so to use it with a simple pick and place machine I am working on.

author: CoolNamesAllTaken
author_rank: Contributor
timestamp: December 23, 2023, 06:14:51 am
content: Lol, it only took me two years to figure out how the notifications work here. Very cool! Thanks for sharing your build
For Alan W2AEW Ramp generator  - Page 1
Forum section: electronics / projects

author: M0BSW
author_rank: Frequent Contributor
timestamp: October 13, 2013, 12:44:35 pm
content: Hi Alan I finished and boxed the Ramp Generator following our discussion Brilliant piece of kit , suppose I should setup this receiver I have now, Thanks Alan, I'm learning more from you than The Art of electronics sat here, looking forward to the next project, here's a picture of my Version

author: Jebnor
author_rank: Regular Contributor
timestamp: October 15, 2013, 04:45:46 am
content: Very nice, I may have to build one myself.

author: w2aew
author_rank: Super Contributor
timestamp: October 16, 2013, 04:08:13 am
content: Nice job! It's nice to know that some of these projects live long past the time that I've removed them from my breadboard.
For all the homeboys designing discrete power supplies - Page 1
Forum section: electronics / projects

author: T3sl4co1l
author_rank: Super Contributor
timestamp: August 05, 2020, 05:14:49 am
content: There is actually an IC for that too:https://ww1.microchip.com/downloads/en/DeviceDoc/mic5159.pdfMIC5156 to 5158 also (wide voltage range), the latter two (7 and 8 ) which have a charge pump to power an N-ch output!Most of them don't have current limiting (indeed most of the examples in the linked datasheet, don't show current limiting; how do they show a ~constant-power limit curve then..?!).Family e.g. here:https://www.digikey.com/products/en/integrated-circuits-ics/pmic-voltage-regulators-linear-regulator-controllers/757A lot are the more specialized type, an N-ch source follower. Compensation is much easier, but to get low dropout, the controller needs a higher supply voltage. It's convenient, when you can get away with it. A good use-case is a system with 12V available, needing a handful of outputs say 1.8-3.3V, supplied from 5V.Or the lower voltage version, which you might use to get 1.8, 2.5V etc. from a 3.3V common rail, when 5V is handy. Here's an integrated one:https://www.ti.com/lit/ds/symlink/tps74801.pdfTim

author: exe
author_rank: Unknown
timestamp: August 05, 2020, 07:02:03 am
content: There are more:https://www.analog.com/en/parametricsearch/11478#/("Discrete Pass Element Linear Regulators (LDO)"). My favouriteLT1575* seems to be designed for Pentium 1 processors (at least my impression from app not 69https://www.analog.com/media/en/technical-documentation/application-notes/an69f.pdf). It has current limit too.Micrel parts are, unfortunately, low voltage.*I never tried it myself as had troubles to find it.
For anyone who is looking to build cheap robots! - Page 1
Forum section: electronics / projects

author: rickey1990
author_rank: Regular Contributor
timestamp: April 21, 2015, 09:13:12 pm
content: Recently I have been working on a blog with lots of designs for cheap robots, bit of a big project for me, still some editing to do, fix afew bugs. But i fort id share it with you:http://beambuilder.blogspot.co.uk/Also have a kickstarter campaign you may be interested in @https://www.kickstarter.com/projects/2107586344/robot-pcb-kits?ref=nav_searchRickey.

author: JBaughb
author_rank: Regular Contributor
timestamp: April 21, 2015, 09:19:19 pm
content: I had a book i purchased in the 90s called "Bug bots" or something long those lines. Yours bots reminds me of those only style bots that were popular then. Repurposed gear from Walkmen and VCRs, etc.Just curious though. What makes your platform stand out from the countless other microcontroller platforms? Seems like the markets been flooded with these.

author: rickey1990
author_rank: Regular Contributor
timestamp: April 21, 2015, 09:26:27 pm
content: Most of these robots don't use micro controllers, they use the inverters in the Ic's as artificial neurons. So there's no programming. Also its cheap. You can have a 4 motor walker with legs made out of pipe cleaners and it would teach itself to walk.Most of the designs are based on robots from 20years ago, With the advent of microcontrollers this type of robotics didn't really get its chance. So its something id like to see popular again.Rickey.

author: RoboTechEd
author_rank: Regular Contributor
timestamp: April 21, 2015, 09:30:11 pm
content: Are you considering making a video for your kickstarter? I remember doing a study a couple of years back in college and discovered that a key to successful kickstarters is a video. Quality isnt quite as important when you get to asking for less money, so anything to explain it may help
For dual output power supply, is parallel or series regulators better? - Page 1
Forum section: electronics / projects

author: dlucy67
author_rank: Contributor
timestamp: December 24, 2016, 03:00:48 am
content: When designing a bench power supply with two variable output voltages, which is better? A parallel configuration of regulators, both regulators being fed simultaneously from the rectifier or current-limiting stage? Or a series configuration of the higher-set regulator feeding both the higher-voltage device output and the lower-voltage regulator input? Why?(Please feel free to point out anything I'm doing wrong in my simple, assembled-from-the-datasheet design while you're at it).Thanks!

author: tautech
author_rank: Super Contributor
timestamp: December 24, 2016, 03:11:59 am
content: Parallel2 totally independent voltages are available up to the max supply less losses of course.

author: jeroen79
author_rank: Frequent Contributor
timestamp: December 24, 2016, 04:19:32 am
content: In series mode the last output will not be able to go higher than a volt or two below the before last regulator.In parallel each can be set fully independently.But if you want fixed 6V and 12V this won't matter.And in series mode the before last will have to dissipate power for it's own consumers and part for the last regulator, so it will be hotter.The last regulator will only need to dissipate the last step so it will run cooler.In parallel each will dissipate depending on it's own output and load.If a large majority of current is used by the lower output then series could be a way to relieve one regulator. Otherwise it will unevenly stress the higher regulator and parallel would be better.Decide on an expected usage profile and calculate the dissipation for parallel and series.

author: Simon
author_rank: Unknown
timestamp: December 26, 2016, 05:45:06 pm
content: It really depends on what you are doing. At the end of the day you are dissipating the same heat.Sent from my phone so mind the autocorrect.
For experts: What are the functionalities of these components? - Page 1
Forum section: electronics / projects

author: jacop.abraham
author_rank: Newbie
timestamp: March 15, 2017, 10:36:44 am
content: Helloon thislinkthere is a PoE demo board from Linear Technology. I wanted to know what do the Components D12, R20, C16, R19, D11, D13 und C17 actually do here.Thx in advanceJakub

author: rstofer
author_rank: Super Contributor
timestamp: March 15, 2017, 02:31:51 pm
content: Hold the MOSFET off during startup?

author: jacop.abraham
author_rank: Newbie
timestamp: March 15, 2017, 02:39:45 pm
content: Assume is true. In this case the components D12, R20, C16 are sufficient for this function and no need for the other components! am i right?

author: rstofer
author_rank: Super Contributor
timestamp: March 15, 2017, 05:34:58 pm
content: How about the other parts pull the gate down when the power rail goes down to prevent the gate from going a lot higher than the drain. They also discharge C17 and C16.If might be useful to look at the definition of the NGATE pin.I would be willing to bet that all the parts are there for a reason.

author: jacop.abraham
author_rank: Newbie
timestamp: March 16, 2017, 11:22:49 am
content: I would be willing to bet that all the parts are there for NO reason.
For what this filter is used ? - Page 1
Forum section: electronics / projects

author: namster
author_rank: Regular Contributor
timestamp: August 01, 2020, 10:52:45 pm
content: Hi All ,i trie to understand the compensation loop of the QL355 , for the voltage amplification they use a diffierential Amplifier with a gain of 0.049 that can sense voltage remote or localy , the circuit seems to be under damped i shared the bode diagram of the circuit , What is the use of this Capacitor ?
Fork contact SIL pin headers - Page 1
Forum section: electronics / projects

author: djsb
author_rank: Super Contributor
timestamp: November 28, 2010, 12:28:57 pm
content: Does anyone know where I can buy SIL headers as shown in this linkhttp://www.mpe-connector.de/index.php?lang=en&menu=4&id_product=0451&segments=197&segments=986&segments=769&segments=1189&segments=1607&order_code=045-1-001-D-S1T-XS0&action=Show_datasheet#toppageI don't know which search terms to use when looking on the farnell or RS websitesAny help appreciated.Thanks.
FOSS Filter design suite with KiCAD/LTspice schematics as output - Page 1
Forum section: electronics / projects

author: Detzi
author_rank: Regular Contributor
timestamp: February 09, 2020, 07:26:02 pm
content: Good Day,in the past weeks i worked on a tool that creates active and passive electronic filters based on the inputs a user makes. You can choose from a wide variety of pole calculations as well as a few different architectures. The Program looks like this:For the output format you can select for example a Eeschema format which has everything preset to be evaluated with its current NGspice. Of course you can also decide to create a simulation file for LTspice or just output plain text.The GitLab repo is located herehttps://gitlab.com/IBDetzler/ibdfcand you can find pre-build versions of the program for Linux and Windows based systems on my Websitehttps://www.ing-detzler.de/ibdfc.html. I tested the builds to run under Windows 10, Fedora 31, Ubuntu 18.04 and 19 but they should run on almost any distro.I hope my program can be of good use to someone, i have applied a GPLv3 License to it so it should be easy to integrate in other Projects. Let me know of your thoughts and maybe we can work together on a future version :slight_smile:
FOSS pipeline for simulations using the PCB layout/3D model - Page 1
Forum section: electronics / projects

author: BadeBhaiya
author_rank: Regular Contributor
timestamp: August 23, 2024, 08:49:42 am
content: Hey guys I've been searching around on the internet if anyone has figured out the entire FOSS simulation pipeline after generating gerbers/3D step file.Altium and all the other commercial packages have numerous plugins to do current density simulations, temperature rise, emitted stuff, you name it.FOSS too has a tool for everything, but there is limited integration. I have seen some videos on youtube tutorials where people use OpenEMS or freecad FEM workbench or ElmerFEM etc to do sims from exported gerber files.
Found a NOS stash of ST62E28 ROM MCUs. How were they programmed? - Page 1
Forum section: electronics / projects

author: Yansi
author_rank: Super Contributor
timestamp: July 30, 2019, 04:59:36 pm
content: Hello,I have found a NOS stash of ST62E28 ROM MCUs. Out of curiosity, does anyone have a documentation how these were programmed? I can google the name of the tool, heck I could even find one with the software to run it, but I am more interested how the programming interface was done on these old MCUs.I have aST62E28CF1 (datasheet), which is a cerdip with UV erasable ROM inside. From the datasheet that can be easily found on google, I can clearly see there is a 12.5V Vpp pin. However I do not see any further description how is the data transfered inside.Have anybody used these 8bit oldtimers?Thanks

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: July 30, 2019, 05:05:11 pm
content: A lot of these early EPROM MCUs had a programming interface identical to EPROMs, just needing a pinout adapter and a standard EPROM programmer.

author: amyk
author_rank: Super Contributor
timestamp: July 31, 2019, 02:25:26 am
content: You are in luck, a year ago someone asked on here about how to program a different member of the ST62 series, and I found the programming spec:https://www.eevblog.com/forum/microcontrollers/need-to-programm-a-st62t10-mcu-help-finding-a-cheap-programmer/msg1620967/#msg1620967

author: Yansi
author_rank: Super Contributor
timestamp: July 31, 2019, 10:05:42 pm
content: Nice one! Thanks for sharing. Have had a quick look, it didn't look much like any regular EPROM.
Found a Solution to Rittal Panel Keys! - Page 1
Forum section: electronics / projects

author: nick.sek
author_rank: Regular Contributor
timestamp: October 04, 2013, 03:10:03 am
content: Every two meters at my work, we have a Rittal Panel and tons of relating keys,Came up with a solution!http://youtu.be/9GJtnOESWJ4

author: hikariuk
author_rank: Unknown
timestamp: October 04, 2013, 07:07:56 am
content: Quote from: nick.sek on October 04, 2013, 03:10:03 amThat's what we used to use them for when I was working in industrial automation.

author: nick.sek
author_rank: Regular Contributor
timestamp: October 08, 2013, 10:03:17 pm
content: It is there sole secondary purpose, props to the man you came up with idea to make them un-loose-able !

author: tszaboo
author_rank: Super Contributor
timestamp: October 09, 2013, 01:15:09 am
content: Quote from: nick.sek on October 04, 2013, 03:10:03 amAren't they purpose designed for that? Recently I learned how to open beer with a newspaper...
Found a wonderful source for salvaging DIY synthesizer/audio/etc components! - Page 1
Forum section: electronics / projects

author: ChristofferB
author_rank: Frequent Contributor
timestamp: May 19, 2015, 10:55:23 am
content: So I'm slowly getting into analog synthesizer electronics, thankfully, there's a lot of resources on that out there! Now after building a lot of drone oscillators, LFO's, simple VCO's, I thought it'd be fun to actually use these for not just making sounds, thus I decided to start out with a CV/gate (control voltage/gate) keyboard.http://www.musicfromouterspace.com/has some nice designs for exactly that, and even sells PCB kits. Still needed a keyboard, though.I got this silly idea that maybe those electric organs from the 70's would be a good place, since I were pretty convinced that they weren't keys pressing microswitches or membranes, matrix keyboardsetc. (The keyboard needed closing switch per key to a common bus).Now I don't know if this is a Danish/Scandinavian thing, or more widespread, but IN the 70's in Denmark, NO FAMILY WAS ANYTHING if they didn't have one of those electric organs adorning the living room, so they're very common here. Also, they're kinda heavy and large, so people give these away for almost free (if you pick them up yourself).So i got one of those, and started tearing it down. And boy was I right!Here's the top loot:Leslie speaker assembly:Spring reverb assembly (amplifier and all)Some, as I understand, pretty rare synth chips:The AY-1-1313 is a 16 ch. multiplexer-like thing: 16 freq inputs, 16 select (key), and one outputAnd two 3½ octave common bus+switch per key keyboards:The contacts on the keyboards are really nice, some sort of silver plated guitar string like wire, that also acts as the key return spring.+A literal bagful of circuit boards with analog circuits; filters, amplifiers, effects, etc. All with card-edge connectors to plug into a common backplane.It came along with all the schematics, so many modules can be reused as-is. Though some of them require some strange voltages, like: +18 and -27V.Hope some will find this info useful! If you can pick an electric organ up cheap, it's WELL worth it if you're doing synthesizers or other analog stuff.--Christoffer

author: smjcuk
author_rank: Frequent Contributor
timestamp: May 19, 2015, 11:03:04 am
content: Great post. Nice source of parts that. Anything vaguely organ related disappears pretty sharpish and for lots of money here in the UK unfortunately. They're worth more complete than in parts.Currently building a drum machine based on the korg monotribe circuits (current bass drum progress which isn't working well yet:) so I'd love to get my hands on that kind of stuff here!

author: ChristofferB
author_rank: Frequent Contributor
timestamp: May 19, 2015, 01:02:31 pm
content: Thanks! And good luck with the drum machine!.-Another note about these organs: Try to aim for the 70's. the earlier ones are almost guaranteed to be valve-based (which is cool and all, but not so useful for synths), the later ones are probably digital.
Found smd device. Can't figure out what it is. - Page 1
Forum section: electronics / projects

author: namlu
author_rank: Contributor
timestamp: August 05, 2014, 06:48:02 am
content: Hello.I think it may be an eeprom, but I really not sure about that.I do not even recognize the company icon.Searching the text on it finds nothing.I post a picture. Maybe someone here can recognize.Thank you.

author: cyr
author_rank: Frequent Contributor
timestamp: August 05, 2014, 07:01:25 am
content: Looks like a Fairchild microwire EEPROM to me.

author: grumpydoc
author_rank: Super Contributor
timestamp: August 05, 2014, 07:29:51 am
content: Not quite (the right data-sheet), but closehttp://www.alldatasheet.com/datasheet-pdf/pdf/51930/FAIRCHILD/FM93C56.html

author: amyk
author_rank: Super Contributor
timestamp: August 05, 2014, 07:49:58 am
content: FM93CS56, which is similar to 93C56 but has write protection.

author: mikerj
author_rank: Super Contributor
timestamp: August 05, 2014, 10:33:03 am
content: Quote from: grumpydoc on August 05, 2014, 07:29:51 amOut of interest why do you say "not quite"? Itisa Fairchild Microwire EEPROM.

author: namlu
author_rank: Contributor
timestamp: August 05, 2014, 08:18:54 pm
content: Hello guys. Thank you very much.1) How did you know this? How could I do it myself?2) I have another smd chip I don't know what it does. It is also probably an eeprom of flash. Can you figure it out?Front:Back:Thank you.

author: wraper
author_rank: Unknown
timestamp: August 05, 2014, 08:55:26 pm
content: Quote from: mikerj on August 05, 2014, 10:33:03 amBecause FM93CS56 and FM93C56 are not interchangeable both ways.

author: grumpydoc
author_rank: Super Contributor
timestamp: August 05, 2014, 08:59:04 pm
content: QuoteI did not mean that it wasn't a Fairchild microwire EEPROM but that the data-sheet that I linked wasn't for the exact part the OP had.

author: wraper
author_rank: Unknown
timestamp: August 05, 2014, 10:54:37 pm
content: Quote from: namlu on August 05, 2014, 08:18:54 pmLooks like CSI (Catalyst Semiconductor) part (not 100%). CAT....something. If you removed that from RAM stick, it is CAT24C02. Otherwise likely it is something EEPROMish considering manufacturer.How to find: with experience you know what looks like part number among those symbols (they often are with first/last letters omitted), manufacturer symbol, + google. How it is used in the schematic says a lot about it, so at least you can distinguish eeprom from PWM controller. On such small packages there are no even partial part number usually. Just a code of 1-4 symbols which identifies part. Others are code for mfg date, batch, mfg factory....

author: wraper
author_rank: Unknown
timestamp: August 05, 2014, 11:00:30 pm
content: Actually it might be a digital pothttp://www.onsemi.com/pub_link/Collateral/CAT5113-D.PDFDatasheet says ON semiconductor because it acquired CSI a while ago.
Found this old printer, its neat take a look - Page 1
Forum section: electronics / projects

author: moonman94
author_rank: Newbie
timestamp: September 20, 2016, 09:58:51 pm
content: While going though the scrap bin at my local maker space, I ran across this printer with the cover missing. It appently is a "Mite 123P" judging by the dates on the components it was made in 1978. I can not find any real info on it, but the mechanism seems to be full of vodo. So I did a small teardown with some pictures. It appears that it uses a motor to move the carriage, but then it uses a bank of solenoids to move it into the correct character selection. Here is the link to the all the pictures I havehttp://imgur.com/a/GTtFm. Also a very short youtube video of the solenoids in actionhttps://youtu.be/NRILgm6PbLQ. If anyone has any input or info please let me know

author: retrolefty
author_rank: Super Contributor
timestamp: September 21, 2016, 01:45:08 am
content: I believe that these were used (at least for one use) on SAC 'Looking Glass' KC-135 missions. It's basically a teletype but much more weight and volume efficient as airborne service prefer. I was in the USAF in the late sixties performing teletype/crypto maintenance but this unit was not part of tech school so no first hand knowledge other then hearsay. Your unit looks newer then what was flying in the 66-70 time frame because of the ICs.
Four band audio bargraph display, using IN-13 Nixie linear bars. - Page 1
Forum section: electronics / projects

author: schmitt trigger
author_rank: Super Contributor
timestamp: November 19, 2019, 01:25:03 am
content: A couple of years ago, I stumbled upon an IN-9 Nixie linear display datasheet in Russian.Some members, helped me translate it and my curiosity was piqued.I was able to obtain some IN-13 tubes on Ebay (they are longer and more linear) and after making some static displays, decided that it would be best if I made an audio VU display.Almost simultaneously, I found the MSGEQ7 Seven Band Graphic Equalizer IC, and decided that it would be a better project.This IC provides seven bandpass outputs, but since I only had four Nixies, I combined them into low, mid-low, mid-high and high bands.I finally completed the project as shown in the video:https://youtu.be/5oLu2AATviQThe core is a solid block from a Mesquite root, which is hard enough to be machined and provides a very unique and handsome look.The video does not do proper justice how gorgeous this project actually looks in person.

author: SiliconWizard
author_rank: Super Contributor
timestamp: November 19, 2019, 03:48:41 am
content: Nice.
Fourier Series (Sawtooth Approximation) - Page 1
Forum section: electronics / projects

author: @rt
author_rank: Super Contributor
timestamp: October 31, 2015, 11:56:36 am
content: Hi GuysCould someone explain why there are two different circular animations about YouTube for Fourier Series Sawtooth animation?Here’s one example where every second circle is rotating clockwise:Yet the Wikipedia example here is different:Wouldn’t these be two entirely different formulas?At the very least I think theta would alternate positive and negative for the first example only.I put this in projects section because it is a software project. I have been making my own.Cheers, Brek.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: October 31, 2015, 12:20:16 pm
content: Probably, because cos(-x) = cos(x)? For even harmonics, the direction of rotation doesn't matter, because they always have the same vertical component relative to the rest.Tim

author: @rt
author_rank: Super Contributor
timestamp: October 31, 2015, 12:30:39 pm
content: Lol can we forget the whole thing and make this thread go away?There must be an issue with my rotation.When I reproduce the second animation, as the iterations get near 200 or so,the sawtooth becomes as good resolution as infinite is going to get on a limited resolution screen.I can explain and fix the jittery points (it’s because I’m only connecting every third sample).When I reproduce the first one it’s great except there’s a little kink in the middle of the diagonal part of the wave.That is not uploaded though... I’ll look into it again :O
FPC cable protective coating - Page 1
Forum section: electronics / projects

author: jt
author_rank: Regular Contributor
timestamp: November 01, 2015, 07:13:06 pm
content: Watching product teardowns I've noticed some FPC cables have a black coating over them similar to the following:http://www.pandawill.com/original-mainboard-fpc-cable-for-zopo-c2-aliyun-os-50-inch-smartphone-p102082.htmlIs this a protective coating against abrasion, and if so does anyone know what it is called or where I could find more information?Does anyone know of any other ways to ruggedize FPC cables (particularly against abrasion in high-vibration environments)?Thanks!
FPC Cables - Page 1
Forum section: electronics / projects

author: Mario87
author_rank: Frequent Contributor
timestamp: August 10, 2021, 07:17:17 pm
content: Hi,Does anyone know where I can source 0.2mm pin pitch FPC cables? I can source connectors no problem and the usual suspects have 0.25mm pitch FPC cables, but I cannot for the life of me source any 0.2mm pin pitch ones anywhere. All seems to be custom made stuff at that size.Any help greatly appreciated!
FPC/FFC connector: China type or reputable brand? - Page 1
Forum section: electronics / projects

author: hcglitte
author_rank: Regular Contributor
timestamp: March 28, 2018, 01:35:29 pm
content: Hi,I currently use this connector from Hirose FH12A-50S-0.5SH(55). It's 50 pin, and gold plated.The cost is 1.5 to 2.5 USD / pcs at 100 quantity, depending on distributor.From China you can get 100 pcs for 25 USD, @ 0.25 USD / pcs. The contact finish is tin.https://www.aliexpress.com/store/product/100pcs-FPC-connector-0-50-mm-4-5-6-8-9-10-12-14-16-20/900038_32840793847.htmlQuite a big difference.It's used to connect a TFT display with gold plated FPC, sitting solid in an enclosure.Hirose states in their datasheet that their connector has very high reliability and so forth.Is it worth the extra cost? Could the less expensive connector fail after some years of usage?I find it difficult to grasp whether the much more expensive one has any benefit. What could potentially go wrong with the less expensive one?Returns are MUCH more expensive of course(!)

author: hcglitte
author_rank: Regular Contributor
timestamp: March 28, 2018, 02:01:04 pm
content: I found this article:http://www.connector.com/gold-or-tin-versus-gold-and-tin/It states that gold should not be mated with tin.

author: RobK_NL
author_rank: Frequent Contributor
timestamp: March 28, 2018, 02:01:50 pm
content: Amphenol FCI counts as a reputable brand also:https://nl.mouser.com/ProductDetail/Amphenol-FCI/62684-50210E9ALF?qs=sGAEpiMZZMs7i6cT6ogu4xCAcU97Lcm6KvZ5YtC1cVU%3dNot as cheap as thosee chinesium parts, but a lot cheaper than Hirose.

author: hcglitte
author_rank: Regular Contributor
timestamp: March 28, 2018, 02:32:17 pm
content: Thanks, great! They will even fit the same footprint, with lightly wrong side pads - but that won't matter anyway.Still, I have a reel of 1000 pcs of 14 way similar connector for another smaller LCD.Here there still the tin/gold potential issue would be present. I am not sure if I should toss the connectors, and buy gold plated ones...
FPGA: DDR3 routing and pin assignment on Spartan 7 (noob question) - Page 1
Forum section: electronics / projects

author: Nolly
author_rank: Newbie
timestamp: June 09, 2025, 06:32:34 pm
content: Hello,For one project I need some speed, power and memory so I decided to add an FPGA.I chose a Spartan 7 (XC7S15 in 225 BGA) and 16bits DDR3 (Hynix H5TQ4G63EFR-RDC, only one package).I'm basing my design on the Xilinx HW-S7-SP701 reference design.Disclaimer: I'm a total noob with FPGA and it's my first time with DDRSo I did recopy the DDR part of the reference design but of course the Spartan comes in a bigger packages in the ref design and it's not easy-routing-compatible right now.My nooby questions is the following:To what extend can I swap the IOs pins of the DDR to get a nice routing?For a fixed DDR pinout at controller's side I know that I can swipe data bits between bytes groups, that's OK.But I do have an FPGA wich is super flexible. So I guess I can assign almost any internal signals to any outputs pins (I plan to use the Memory Interface Generator of Xillinx), with the following limitations:- same bank (I have actually 2 banks, one is dedicated for DDR)- pins labelled as "DQS" are used for DDR strobe, so don't touch them. Datasheet says: "T0_DQS, T1_DQS, T2_DQS, or T3_DQS. The DDR DQS strobe pin that belongs to the memory byte group T0–T3"- some others considerations I'm not even aware of yet?So can I reorder all the IOs as I want (data, address, commands...), given I stay on bank34 and keep the DQS for strobe/clock?ThanksLeft: Xilinx reference design,Right: mine
FPGA o/p state during startup - Page 1
Forum section: electronics / projects

author: electros6
author_rank: Regular Contributor
timestamp: August 16, 2018, 05:23:27 am
content: Hi guys ,I like to drive a inverter using FPGA later cyclone II in open loop. After I programmed the FPGA found that results are good expect during startup configuration the output pin is in unknown state. How to avoid this guys.

author: Siwastaja
author_rank: Super Contributor
timestamp: August 16, 2018, 06:36:30 am
content: Add an external pullup or pulldown resistor.
FPGA SPI FLASH for configuration - Page 1
Forum section: electronics / projects

author: electros6
author_rank: Regular Contributor
timestamp: June 26, 2014, 03:14:26 am
content: Hi guys,I like to use a lattice FPGA in one of my projects. what I need to know is whether xilinx, atmel or any other SPI flash can be used as configuration flash for the lattice FPGA or I have to use the lattice SPI configuration flash only.

author: amyk
author_rank: Super Contributor
timestamp: June 26, 2014, 11:19:16 am
content: The ones they specifically designate as for FPGA configuration are ones they've tested and support, but any part with the right interface and timing requirements should work.

author: nctnico
author_rank: Super Contributor
timestamp: June 26, 2014, 05:43:58 pm
content: The Spartan6 devices from Xilinx support loading from a generic SPI flash. You can even program the flash through the FPGA using JTAG (although it is a bit slow).
FR2 double sided PCB material with photo resist in the uk - Page 1
Forum section: electronics / projects

author: Anks
author_rank: Frequent Contributor
timestamp: June 13, 2016, 05:13:54 pm
content: I'm looking to get some double sided FR2 material that also has photo resist in the UK. I'm also after reasonably large pices such as 200mm x 300mm but I'm finding FR2 hard to come by with photo resist.I've considered adding the resist myself but would rather skip the extra steps. Also if anyone knows of a overseas supplier that produces such a product I'll also be interested.Kris

author: Buriedcode
author_rank: Super Contributor
timestamp: June 13, 2016, 11:43:04 pm
content: I assume you're after FR2 because its kinder to drill bits for DIYing? Thats why I used it a lot for homemade PCB's, but... given the prices to get a reasonable double sided, PTH PCBs made in china (even with <7 day shipping time) my basic toner-transfer and UV stuff is gathering dust.I believe rapid carry double sided pre-sensitized boards made of CEM1. It's also less harsh on drill bits than FR4, and has the added benefit of being an 'off-white' colour, making it very nice for LED arrays in lightboxes. A hack-saw, whilst not the best way to cut PCB material works very well with these.http://www.rapidonline.com/economy-photo-etch-printed-circuit-board-29439

author: Anks
author_rank: Frequent Contributor
timestamp: June 14, 2016, 11:43:54 am
content: I'm guessing by what you say this is hard to cut like fr4 just better on drill bits. I'm thinking maybe a good idea to alter my design to fit a standard size.

author: Unknown
author_rank: Unknown
timestamp: June 14, 2016, 03:34:14 pm
content: I use the 'economy' board from Mega Electronics:http://megauk.com/pcb_laminates.phpIt's a laminate, fibreglass on the outside with a paper core. It cuts straight in a guillotine like fr4 without shattering but having the soft core you can drill it with standard HSS bits. They sell it in up to 12" x 24" sheets too so it may be of use to you.
FR300 how to do slots? - Page 1
Forum section: electronics / projects

author: alank2
author_rank: Super Contributor
timestamp: November 26, 2020, 08:40:07 pm
content: I'm working on a NES that has a RF module soldered on the board and it has four 3/16" slots that connect it. I've got one side of the slot clean with the FR300, but I can't get the other. There isn't much room to press the slot away from the slotted pad. Any ideas?
FRA using TopSPICE - Page 1
Forum section: electronics / projects

author: rbola35618
author_rank: Frequent Contributor
timestamp: May 26, 2019, 02:59:11 pm
content: Hi EEVbloggers,In this video, I show a new FRA (Frequency Response Analyser) feature in TopSPICE. You can extract an AC loop response (Gain and Phase) using a switching model. Only some simulator can do this function. I show how to setup the simulator and how to plot the loop gain and phase. You also take the plot of the plant (output filter) and the error amp frequency response. Penzar Development just implemented a variable amplitude table where you can select both the frequency and amplitudes of the stimulus generator. What this does is to prevent overloading the error amp and causing error in your open loop plots. The simulation take about 3 to 5 minutes to perform depending on the speed of your computer. I have a old computer so my simulations take longer than most (I edited the simulation times).I compare the results to LTSPICE and show that both plots are similar. Being able to plot a loop response using a switching model is very useful if you have a new typology or do not have an average model.Only a few simulator such as PSIM, Simplis/Simitrix can do AC analysis using a switching model. However, both of these simulator are not SPICE base so your transient may not be as accurate. However, the AC analysis using the switching model are very fast. But also keep in mind that these simulator cost in the thousands of dollars.LTSPICE can also be used to do AC analysis using the switching model. However, you have a limited amount of components in the library and also keep in mind that Analog Devices took over Linear Technology. How long will Analog Device support LTSPICE?I am in no way connected to Penzar Development, and do not get any commission. I am just a satisfied customer. Penzar Development has a really good technical support staff and have always added models that I have requested to the library. I approached Penzar Development if they could implement this FRA about a 1 month ago and they were responded my implementing it. So they are very good in supporting their customers request. Then I asked them to add the variable amplitude table and they added that feature this past week. So far I have been getting good results.If you mentioned my name, Robert Bolanos, you can get a 10 percent discount. If you are a College or a University student, if you show proof that you are a student and mentioned my name, you can get 50 percent discount.I hope you find this video useful.The FRA will not run on the demo version of Topspice.Questions and comments can be sent to rbola35618@aol.com. If you like this video, please share, subscribe and give a thumbs up. If you mention my name, Robert Bolanos, as a referral, you will get 10% discount. If you are a University or college student, and if you show proof that you are a student and mention my name, you will get 50% discount off of the price.
Fractal Images using High Voltage Transformer - Page 1
Forum section: electronics / projects

author: firepower
author_rank: Regular Contributor
timestamp: June 08, 2015, 06:24:06 am
content: http://imgur.com/a/PSmcr

author: miguelvp
author_rank: Super Contributor
timestamp: June 08, 2015, 04:20:20 pm
content: Winter 2012-2013 Chicago, I found these patterns all across the back porch banister, It's ice forming in the wood due to moisture in the air and freezing in some parts of the wood and not others.Took a bunch of pictures but all the patterns were different and they resembled more like julia and mandelbrot sets, and some of them looked like hopalong strange attractors.I'll post more pictures of the banister if anyone wants to look at other sections of it.

author: German_EE
author_rank: Super Contributor
timestamp: June 08, 2015, 07:48:04 pm
content: https://en.wikipedia.org/wiki/Lichtenberg_figureAlso seen on people after they have been struck by lightning.
Frame clip and locking pin for Velleman K8200 3D printer - Page 1
Forum section: electronics / projects

author: Unknown
author_rank: Unknown
timestamp: January 07, 2014, 10:05:28 pm
content: Hi,Here is just a quick update on my latest addition to the 3D printer.As you know (or maybe not) mounting any accessories on the printer’s frame is a bit inconvenient. It is a good idea with these square nuts slid in the frame but unfortunately if you want to add something after the printer is fully assembled – it can be very ungrateful.Some of the areas are easy to be modified, like the vertical aluminium profiles – it requires just removing the top caps. However, some areas are very hard to access (like the Z carriage arm) – you would need to tear the printer apart to get into the groove in the aluminium profile.I had to figure out how to hang something on the frame without disassembling the printer or drilling holes in the frame.To download the files - visit my profile on Thingiverse (http://www.thingiverse.com/ljwinkler/designs) or use direct links below:- bracket (http://www.thingiverse.com/download:409393)- pin (http://www.thingiverse.com/download:409394)More details/photos here:http://ljwinkler.blogspot.ie/2014/01/frame-clip-and-locking-pin-for-velleman.htmlFor latest updates/projects please subscribe to my blog:http://ljwinkler.blogspot.com/Cheers
Frangibolt Driver Circuit - Page 1
Forum section: electronics / projects

author: arul
author_rank: Regular Contributor
timestamp: September 22, 2018, 10:26:46 am
content: Hi,I am looking for frangibolt driver circuit which can be enabled from MSP430FR5969 microcontroller. Now am constructed driver circuit using n-channel mosfet. Before that as well as transistor can be used to drive the mosfet.Frangibolt Datasheet ->ftp://apollo.ssl.berkeley.edu/pub/MAVEN/MAVEN%20Parts%20Selection/9_Actuators/TiNi%20Frangibolt%20FC2_16_31SR2.pdfMicrocontroller Datasheet ->http://www.ti.com/lit/ds/symlink/msp430fr5969.pdfMicrocontroller operating voltage: 1.8V to 3.6V, but i designed under operating voltage of 3.3VThe diver circuit input voltage is 28V, because the frangibolt operated at 28V so i choosen.I have attached what i can done of circuit.Please suggest to improve my design...Advances in thanks...

author: rstofer
author_rank: Super Contributor
timestamp: September 22, 2018, 05:18:15 pm
content: I don't know how the circuit will respond to startup transients.I think the input diode is backwards.Consider what happens when the microcontroller starts up. Usually, the output pin is floating and that might be fine but I would add a pull-down resistor the the base of the first transistor. I want to KNOW that it is off, not just sitting there with a dangling base.When the code starts, it is important to set the pin output to the proper output state before actually configuring the pin as 'output'.Overall, I wouldn't use the circuit. I am not at all convinced that it couldn't be induced to misfire. At a minimum, I might add a physical relay to the 28V supply and control it from a second pin of opposite polarity. One output would be a '1' to fire and the other would be a '0' to fire. I might even go further... I would almost certainly have some kind of toggle switch in the 28V supply.

author: ajb
author_rank: Super Contributor
timestamp: September 22, 2018, 08:41:04 pm
content: D57 will prevent your MCU from activating the circuit. Otherwise your circuit looks like it will work, but it will work just as well if you get rid of everything except Q50, R421, and D56 and just drive the gate of Q50 from the MCU directly (you still want the external pulldown that R421 provides).rstofer's suggestion to add a separate enable signal is a good one. I would suggest adding a time delay (RC filter) component to the enable signal, so that a momentary glitch can't result in an accidental activation of the frangibolt. That way you have to supply the enable signal some time before you intend to activate the bolt to 'arm' it, before the 'fire' signal will be effective. You could also interlock the two signals so that the arm signal is only effective if the fire signal is inactive.
Frankenstein two welders  - Page 1
Forum section: electronics / projects

author: ZombieWelder
author_rank: Newbie
timestamp: October 22, 2018, 01:50:20 am
content: Hello dear internet folks!I'm rigging a drive motor that's a bit oversized for the cheaper harbor freight machine. The circuit that drives the 24v DC motor produces only 22v that's not enough particularly when I add the gas magnetic valve. My all purpose power supply makes the motor happy with 0.65A and 25V , the gas valve pulls about 0.4A .I'm having hard times uploading pictures .It seems 24v AC coming in drives a big 220v contactor that switches the power to the main transformer, some of that 220v gets down to 24dc by a rectifier? 892h-1ch-c no7/nc5A. Wich drives the motor. The speed I'm guessing is changed by a triac jrf730 and potentiometer B470k there's a tiny IC I can't make out the numbers of and some capacitors and passives I don't think matter but IDK I'm a noob:/Any help much appreciated! !!Sent from my SM-G870W using Tapatalk
Free 3D model STEP file viewer I can recomend to customers...  - Page 1
Forum section: electronics / projects

author: Smokey
author_rank: Super Contributor
timestamp: September 29, 2015, 09:35:20 pm
content: I have to give out 3D models of some products occasionally to non-engineer types that want to see what our products look like. I usually need to also direct them to a STEP file viewer since they don't have anything installed already. I used to point them to the CadFaster QuickStep viewer, but that's no longer available.Any recommendations on a free STEP viewer, preferably from a reputable company that I won't have to convince customers that it's not spyware?

author: IconicPCB
author_rank: Super Contributor
timestamp: September 29, 2015, 10:42:29 pm
content: Check out VariCad viewer

author: voltsandjolts
author_rank: Unknown
timestamp: September 30, 2015, 09:41:16 am
content: FreeCADhttp://www.freecadweb.org/

author: cncjerry
author_rank: Unknown
timestamp: September 30, 2015, 03:05:11 pm
content: Can you output 3DXML? if so, use the free Dassualt product.

author: Lukas
author_rank: Frequent Contributor
timestamp: April 03, 2016, 11:52:46 am
content: Quote from: blueskull on September 30, 2015, 11:30:39 am+1 For FreeCAD, I've had no issues with it importing and using STEP files from various manufacturers

author: wreeve
author_rank: Unknown
timestamp: April 03, 2016, 07:58:28 pm
content: http://cadexchanger.com/Brilliant as a viewer as well.

author: ChunkyPastaSauce
author_rank: Unknown
timestamp: April 03, 2016, 08:17:38 pm
content: If they only need to visually look at the model (no measurements), then you might consider exporting to 3D PDF since the probably already have acrobat installed

author: gkv311
author_rank: Newbie
timestamp: January 16, 2017, 08:39:35 pm
content: Just to fulfill information on this topic - there is also CAD Assistant, free 3D Viewer supporting STEP format (with assembly structure and colors) as well as several others.It can be also used for converting STEP model into mesh formats like OBJ/STL/PLY:https://www.opencascade.com/content/cad-assistant

author: Spikee
author_rank: Frequent Contributor
timestamp: January 16, 2017, 11:35:24 pm
content: Generate a 3D pdf ?

author: emsnickw
author_rank: Contributor
timestamp: March 09, 2020, 11:22:20 pm
content: I think he meant to generate a PDF with 6 orthogonal views and/or an isometric view.The share feature in this (https://www.emachineshop.com/free-online-step-file-viewer/) works well and doesn't require installing anything which is a plus.

author: ChunkyPastaSauce
author_rank: Unknown
timestamp: March 10, 2020, 12:02:16 am
content: viewer.autodesk.com is free with decent output and has additional features beyond pure viewing. Anyone with model share link can view.I took example model from fusion and exported to step file, then imported the step to viewer.autodesk.comFor example output seehttps://autode.sk/3cJqC2J
Free: Bob Pease on Analog book volume 1 - Page 1
Forum section: electronics / projects

author: Tom45
author_rank: Frequent Contributor
timestamp: July 13, 2016, 04:24:55 pm
content: Don't think this has been mentioned here. Electronic Design has published an eBook based on Bob Pease's column. Volume 1 is available for download:http://electronicdesign.com/Electronic_Design_Library_Bob_Pease_eBook1_Vol._1

author: linux-works
author_rank: Super Contributor
timestamp: July 13, 2016, 04:52:51 pm
content: direct url:http://electronicdesign.com/site-files/electronicdesign.com/files/uploads/2015/08/FOCUSON_BobPeaseAnalog.pdf

author: CatalinaWOW
author_rank: Super Contributor
timestamp: July 13, 2016, 07:54:57 pm
content: It's good to see these columns again. Even better to find them collected.

author: ez24
author_rank: Super Contributor
timestamp: July 13, 2016, 08:12:28 pm
content: Quote from: Tom45 on July 13, 2016, 04:24:55 pmPut a copy of this in Beginners BookToday is analog day

author: user99
author_rank: Contributor
timestamp: July 13, 2016, 10:06:58 pm
content: I was looking for a collection of the Pease Porridge articles earlier today and found thiswww.ti.com/ww/en/bobpease/assets/www-national-com_rap.pdf

author: ez24
author_rank: Super Contributor
timestamp: July 13, 2016, 11:16:11 pm
content: Quote from: user99 on July 13, 2016, 10:06:58 pmDownload locks up on me but I am starting a new topic on Pease with a link that did work