hybridfree/eevblog-posts huggingface dataset:
ESP32 suitability as a display driver? - Page 1
Forum section: electronics / projects

author: e100
author_rank: Frequent Contributor
timestamp: May 21, 2024, 04:10:16 am
content: Over the last few months several relatively inexpensive mobile phone sized displays driven by ESP32 chips have appeared on the market.I'm guessing that this is just a cost saving measure to avoid using a dedicated driver chip.Is the ESP32 suited to this kind of job, and if so, is this the future direction of large displays in embedded applications?

author: Smokey
author_rank: Super Contributor
timestamp: May 21, 2024, 06:21:04 am
content: https://www.eevblog.com/forum/projects/esp32-s3-lcd-interface/

author: e100
author_rank: Frequent Contributor
timestamp: May 22, 2024, 05:57:26 am
content: When I first saw the specs of the S3 I was puzzled by the decision to remove the ethernet controller.Even stranger was the later appearance of S3 boards fitted with an external Wiznet ethernet chip.Now in hindsight it looks like they removed the ethernet silicon to make room for a graphics chip.

author: Smokey
author_rank: Super Contributor
timestamp: May 22, 2024, 07:55:47 pm
content: One downside, apart from only doing RGB565, is that it uses up just about all the pins. I had to add back in two IO expanders to that design.

author: tooki
author_rank: Super Contributor
timestamp: May 24, 2024, 11:44:58 am
content: Quote from: Smokey on May 22, 2024, 07:55:47 pmThis really is the one enduring limitation to the ESP32 platform: the lack of models with truly large numbers of GPIOs. I wonder why they haven’t made anything with the dozens and dozens of GPIOs found on some STM32 or Atmega models, for example.

author: langwadt
author_rank: Super Contributor
timestamp: May 24, 2024, 12:14:30 pm
content: Quote from: tooki on May 24, 2024, 11:44:58 ammaybe the die would have to be bigger to fit more IOs

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: May 24, 2024, 12:41:50 pm
content: Quote from: langwadt on May 24, 2024, 12:14:30 pmProbably - also may need expensive changes to all the fiddly hand-fettled RF stuff if they changed the physical die layout.

author: tooki
author_rank: Super Contributor
timestamp: May 24, 2024, 01:03:56 pm
content: Quote from: langwadt on May 24, 2024, 12:14:30 pmBy some trivial amount. I don’t think the registers and driver circuitry for GPIOs are particularly large.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: May 24, 2024, 01:07:03 pm
content: Quote from: tooki on May 24, 2024, 01:03:56 pmNo but the bond-out pads can be - look at the die shot herehttp://electronupdate.blogspot.com/2018/08/espressif-esp32-teardown.html

author: langwadt
author_rank: Super Contributor
timestamp: May 24, 2024, 01:08:26 pm
content: Quote from: tooki on May 24, 2024, 01:03:56 pmbut the pads arehttps://en.wikipedia.org/wiki/ESP32#/media/File:ESP32-Dieshot.jpg
ESP32-WROOM-32 Footprint - Page 1
Forum section: electronics / projects

author: NorthernWing
author_rank: Contributor
timestamp: May 05, 2021, 06:37:53 pm
content: Anyone around here used these cheap Espressif wireless modules on anything? If so, how'd you dimension the center pad in your footprint?Unless I'm an idiot, something is wrong here. Looking at the drawing of the module (first attachment):Using the bottom left corner as a reference point (0,0), it looks like the center of that exposed pad should be at (8.3, 10.65). Mirrored, because bottom view. Simple enough.Now looking at their PCB footprint drawing (second attachment):Using the bottom left corner, the center of that pad is dimensioned at (8.0, 10.51).I can't wait for the day when these manufacturers collectively hire at least one person that's even remotely competent for their datasheets, because these drawings look like they were made by a child even when they're not blatantly incorrect. Guess that's why they're $2/ea.I don't think the 0.3/0.1mm will make much of a difference for something this big, but anyone that's used these have any thoughts on which one is correct?Edit: Unrelated, but did Inline Thumbnail attachments break sometime in the last year?...

author: exe
author_rank: Unknown
timestamp: May 05, 2021, 06:42:20 pm
content: Pretty much all footprints I've seen were bigger than IC/module itself and they expand a bit outside, otherwise you won't be able to easily inspect the solder joint and it will be hard solder with a soldering iron. So, mechanical drawing != land pattern.(May be this also helps with component placement, idk.)

author: NorthernWing
author_rank: Contributor
timestamp: May 05, 2021, 06:46:35 pm
content: I understand that, but what I'm saying is that the centerpoint of the exposed thermal/ground pad doesn't match between the mechanical and package drawing. That pad on the package drawing is off by (0.3,-0.14)mm relative to the pad on the mechanical drawing.These seem popular, was just thinking someone that's done a production run/etc with them could chime in.

author: exe
author_rank: Unknown
timestamp: May 05, 2021, 07:59:02 pm
content: I feel like the center pad is actually not in the center, but has an offset right (bottom view). The pcb footprint seems to have offset to the right because it's "top view". If you have the actual device it's easy to measure.

author: floobydust
author_rank: Super Contributor
timestamp: May 05, 2021, 08:26:10 pm
content: Note some dimensions are referenced not to the outer pad's center but instead to the package outline i.e. "18x25.50" so the pads are inset.There's many ESP32-WROOM variants (32D, 32E, 32U, IE, S2, ) etc. Which module are you dealing with?Seeeduses this ESP32 breakout (they have Eagle pcb files). It uses a rounded square pad and silksceen to protect traces and vias from shorting on the underbelly. I think the only danger is paste getting into the via's on the ESP32 MCU so that is why the 9 pads.Another approach is to use the 3D models:https://grabcad.com/library/espressif-esp32-wroomu-1#!https://esp32.com/viewtopic.php?t=9728
esp8266-01 + LTV826 issues - Page 1
Forum section: electronics / projects

author: King_bob
author_rank: Newbie
timestamp: February 22, 2019, 08:47:41 pm
content: I have two questions regarding the below circuit. first, are their any issues with using the GPIO0 as an input for the switch, and as an output for the optocoupler?Secondly, The optocoupler (LTV826) is rated for 1.4v max forward current, but while testing them I had to use at least 2.5v to which it pulls 0.3A to get any decent output. Am I using them wrong or am I not understanding the datasheet? I am guessing 0.3A on the ESP is too much, even for a second?Any additional suggestions are also welcome.thanks in advance.
ESP8266 and Atmega8 I2C Not Working - Page 1
Forum section: electronics / projects

author: Swaroop 21
author_rank: Regular Contributor
timestamp: August 27, 2024, 01:33:30 pm
content: I am trying to establish a connection between a ESP12F and a Atmega8 uC. The Atmega8 is running at 8Mhz. I tried this I2C communication between two normal Arduino Nanos and it worked. Then I tried with another Arduino Nano which I put 8Mhz Bootloader and it worked too. But when I try to use the ESP it doesn't work. I tried both Normal Nano with 16Mhz and at 8Mhz but it doesn't work, I tried pull-up resistors to 3.3V and still doesn't work. Is there any compatibility issue with ESP12 ?This is the Master Side:Code:#include <Wire.h>byte x = 0;void setup(){Wire.begin();}void loop(){Wire.beginTransmission(4);Wire.write("x is ");Wire.write(x);Wire.endTransmission();x++;delay(500);}This is the Slave Side:Code:#include <Wire.h>void setup(){Wire.begin(4);Wire.onReceive(receiveEvent);Serial.begin(9600);}void loop(){delay(100);}void receiveEvent(int howMany){while(1 < Wire.available()){char c = Wire.read();Serial.print(c);}int x = Wire.read();Serial.println(x);}on the slave side it will print the value of 'x'Code:19:04:10.611 -> x is 5119:04:11.146 -> x is 5219:04:11.640 -> x is 5319:04:12.136 -> x is 5419:04:12.635 -> x is 5519:04:13.121 -> x is 56

author: Gadjet
author_rank: Contributor
timestamp: August 28, 2024, 10:33:48 am
content: I've never done it myself but this link makes it seem doablehttps://github.com/cunchem/I2C_esp8266ToArduinoUno

author: Doctorandus_P
author_rank: Super Contributor
timestamp: August 30, 2024, 02:30:31 pm
content: Start with buying one of those Saleaeae clone logic anaysers for EUR 10. (8 ch 24MHz). and use it with Sigrok / Pulseview. It lets you see what is actually happening on the I2C bus, and this determines whether the sender or the receiver has unexpected behavior.You can use the extra channels to output a debug signal, for example toggle a bit every time an ISR is triggered. This lets you correlate what happens on the I2C bus with what firmware of the uC is doing at that same time.Another option is something wrong (or even omitting) the I2C pullup resistors (or even the wiring). If the pullup resistors are not strong enough compared to your bus capacitance and bitrate, then you will never get reliable communication.Beginners also do not always realize both circuits need a common GND for communication to work reliably.Quote from: Swaroop 21 on August 27, 2024, 01:33:30 pmWhat do you mean with "does not work"?
ESP8266 and Parsing Configuration Data - Page 1
Forum section: electronics / projects

author: ludzinc
author_rank: Unknown
timestamp: February 17, 2016, 11:51:44 pm
content: HiI've been tinkering with an ESP8266 and have followed the usual blogs that show how to toggle GOIP using get requests, and this has gone well.I've learnt a bit about HTML as well and my current project is what I would call a 'proof of concept'.My ESP module is a stand alone server / host (no talking to other servers on my network or external agencies) with my phone being the client (remote control) and for this project I want to keep it that way.What I want to do now is have some user configuration data collected on a new page, and save these variables.For example I want the user to be able to change the label on a button from 'Button 1' to 'Front Light'. Or toggle between displaying temperature in F or C.This isn't really practical to do as a get request because aside from parings a ridiculously url, there are some other annoyances that get in the way. For example if you are using a browser that auto-completes your entry you may inadvertently resend an old configuration string, or toggle an IO when you want to only load the front page (bookmarks help here, but imho that's a kludge).What I'm asking, is how do I pass variable in the body of a web page? What magic keywords do I need to search? Know of any good tutorials I should read? Is there a basic concept that I'm overlooking?Thanks all.

author: jdraughn
author_rank: Regular Contributor
timestamp: February 18, 2016, 05:07:00 am
content: Google how you submit a form. For instance, my address bar currently contains "?action=post;last_msg=872072" to give you an idea.

author: ivaylo
author_rank: Frequent Contributor
timestamp: February 18, 2016, 06:30:36 am
content: The ESP8266 doesn't have a real web server, you have to fill the blanks and write your own. Then HTTP is a stateless protocol, so for the different users of your service you need to maintain what is called sessions. Not sure it would work with ESP8266, but if there are no security implications just use cookies. You may need an independent intro to web programming, I'd use web2py or similar until you wrap your head around all that. Then this video helped me appreciate ESP8266 -https://youtu.be/6yYRHyWN7yE
ESP8266 - ArtNet Box - Page 1
Forum section: electronics / projects

author: jmibk
author_rank: Regular Contributor
timestamp: June 04, 2017, 10:59:15 am
content: Hi,i'm designing a tool for stage lighting - a ArtNet -> DMX Box based on ESP8266 with wifi, ethernet, oled display and encoder input. You can download and test the project on Github:https://github.com/jmibk/ESP8266-ArtNet-BoxBasically it works but I like to make it really nice and useable for persons who are interested into it. There are also some issues with the software, I can't fix.So, if you like to test it, feel free. If there are guys who wants to help developing - you're welcome (i can add you to the repo).Discussions welcome - down below.

author: zeubest
author_rank: Newbie
timestamp: April 19, 2018, 10:38:10 pm
content: Hi,Thank you for sharing your project.As I'm buying the needed parts, can you please explain some details ?- "'off the shelf' chinese OLED display" ... there's many chinese oled displays128x64 , 128x32 , color.... can you please be more specific ?- 75176 ... there's no details about it. Is it using the chip itself (then can you explain the full connection) or is it using a module like Grove - DMX512 ?Is there a place to see pictures of your project ?Tks again.
ESP8266 ESP-07S Step model wanted - Page 1
Forum section: electronics / projects

author: diyaudio
author_rank: Frequent Contributor
timestamp: June 15, 2018, 02:47:46 pm
content: Hi peopleI'm looking for a ESP8266 ESP-07S WIFI step model, I found a sketch up version here but I have no tool to convert the format to step used for Altium.https://3dwarehouse.sketchup.com/model/0abaac4e-fa30-4cfb-b274-22ddedcab79d/ESP8266-ESP-07S-WIFI-Module

author: floobydust
author_rank: Super Contributor
timestamp: June 16, 2018, 08:05:34 pm
content: GrabCAD, although not all posted models are in .step format.User Alex Federovhas terrific .step models for Altium, his Russian software makes very compact file sizes compared to bloated SolidWorks.3D Content Centralhas several ESP8266 models.The hard part is finding models that are actually the right dimensions and not super detailed with huge file size.
ESP8266 ESP07 Brownout Clears Flash? - Page 1
Forum section: electronics / projects

author: itdontgo
author_rank: Regular Contributor
timestamp: January 20, 2020, 11:33:32 am
content: We've been using these ESP07 modules and have had a few problems with them. To avoid another step in production we're just using the standard AI Thinker firmware which is good enough. However, I've come across a few now that seem to lose their memory. They're tested working fine and then sometimes they don't boot... and once this has happened it won't work again until it's been re-flashed. They're likely to have been browned out. It's sort of repeatable if we slowly bring the power up.Has anyone come across this. Is there a way to protect the flash memory?They're still working as they attached to the router and the boot loader output works but the AT commands don't work.

author: nuclearcat
author_rank: Unknown
timestamp: May 06, 2020, 05:50:42 am
content: Holding CH_PD and/or RST of module by supervisor IC?

author: kripton2035
author_rank: Super Contributor
timestamp: May 06, 2020, 07:36:33 am
content: it is well known that some cheap esp modules comes with a crappy flash memory chip.it is a good practice to change the eeprom chip inside with a reputable brand one bought from a reputable dealer like mouser or digikey or RSand also install a bigger one so that you can use OTA programming that you can't do with standard 4Mb chip.I also had very strange results from an esp module that I feded with 5v signals on certain pins without knowing itit worked for hours then rebooted with no reason. also the power supply must be as good and stable 3v3 as possible.

author: nuclearcat
author_rank: Unknown
timestamp: May 06, 2020, 10:29:46 am
content: Quote from: kripton2035 on May 06, 2020, 07:36:33 amESP-07 have nasty metal lid, that is much harder than just resolder flash chip.

author: kripton2035
author_rank: Super Contributor
timestamp: May 06, 2020, 11:43:05 am
content: Quote from: nuclearcat on May 06, 2020, 10:29:46 amit is easy to remove them using cheap hot air station, and also to place them back. I do it each time I have a new esp07 coming.
ESP8266 ESP_WROOM_02 Transformer Supply - Page 1
Forum section: electronics / projects

author: csheldon
author_rank: Contributor
timestamp: December 08, 2018, 10:36:10 pm
content: Hi all,I am building a project which would use esp wroom 02 along with some other devices (not exceeding 80mA current consuption)I want to supply power via 330 mA mains transformer (of course with voltage regulators and proper bulking and bypassing ). Does anyone have experience with esp supply? Will this be sufficient?Do I need more powerfull mains transformer?I have read the datasheet, but there is no specific detailing about this,. i've done my research and informations vary. somewhere it states that its peak current draw (spike) is arround 300mA, some state 250 mA.Can anyone with experience please give 2 or 3 words about this?

author: csheldon
author_rank: Contributor
timestamp: December 09, 2018, 09:57:46 am
content: Can I for example take the similiar transformer but with double secondary and then connect that secondary in parallel, so I get double current? Should I worry about phases or both coil phases should be identical?

author: csheldon
author_rank: Contributor
timestamp: December 10, 2018, 10:16:20 am
content: No one?

author: ANTALIFE
author_rank: Frequent Contributor
timestamp: December 11, 2018, 03:34:03 am
content: Why not use a 5V 1A power brick and the use a DCDC to step the voltage down to 3.3V?

author: csheldon
author_rank: Contributor
timestamp: December 11, 2018, 09:42:44 am
content: It has to be transformer. Also I need both 5V and 3V3
ESP8266 Interrupt Acknowledgement - Page 1
Forum section: electronics / projects

author: reflowman
author_rank: Contributor
timestamp: May 11, 2018, 01:37:10 pm
content: My question:Am I right to assume the 8266, at metal, doesn't implement a GPIO "interrupt lockout until the last interrupt is acknowledged" mechanism?Thanks for any help.Context:I'm using standard "interrupt - waitXmS - check pin level" code to debounce a reed switch (max measured bounce 80uS).I'm using stock Arduino 8266 libraries.It works flawlessly for weeks (and is way good enough to read my gas meter) but just occasionally the diagnostics show a glitch (incorrect pin level) has been detected and the glitch is not (99.9% probably not!) due to noise.I've worked out several ways this could happen if there is (a) no int-ack mechanism or (b) there is a mechanism but Arduino code doesn't handle it well enough in edge cases.So far, I haven't found much useful infomation in the Expressif spec sheets. I haven't trudged through much 8266 Arduino code either - and am unlikely to do so!

author: jeduffy
author_rank: Contributor
timestamp: May 12, 2018, 07:29:15 am
content: Not particularly familiar with the ESP8266 libraries, but I know with stock arduino, it has an interrupt every millisecond (to incremement the millis() counter). No idea if it's implemented the same on the ESP8266, but that may be a place to look.
ESP8266 Mains Energy Monitor - Page 1
Forum section: electronics / projects

author: briandorey
author_rank: Regular Contributor
timestamp: January 02, 2016, 12:02:15 pm
content: This is a project myself and my brother have been working on to make an automated way to keep track of electric and gas usage in our home which is logged onhttp://home.briandorey.com/Default.aspxThe circuit uses a ESP8266 module which reads from an ADC to measure mains current via a iSnail current monitor which gives a 0-5V output for 0-100A AC. The gas meter input uses a reed switch on the meter which measures the pulses and the mains meter has an led output which we use to trigger a phototransistor to schmitt-trigger to give clean pulses for the ESP module. We use a FRAM chip to store the meter readings so they are saved in the case of a power cut.WiFi module and circuitThe PCB in the custom caseInstalled next to the electric meterThere are more photos and details about the project on my personal blog onhttp://www.briandorey.com/post/ESP8266-Mains-Energy-Monitorand the source code and pcb files are onhttps://github.com/briandorey/ESP8266-Mains-Energy-Monitor

author: kripton2035
author_rank: Super Contributor
timestamp: January 02, 2016, 01:48:48 pm
content: nice professionnal design !why do you have both an optical reading from the company box, and a current meter in the design ?

author: briandorey
author_rank: Regular Contributor
timestamp: January 02, 2016, 03:06:20 pm
content: We used the current sensor so we could get an instantaneous current reading and the optical sensor on the electric meter so we could get an overall daily or weekly usage report

author: LukeW
author_rank: Frequent Contributor
timestamp: January 02, 2016, 04:41:03 pm
content: Did you mill that plastic box from scratch?

author: and101
author_rank: Contributor
timestamp: January 02, 2016, 04:56:12 pm
content: Quote from: LukeW on January 02, 2016, 04:41:03 pmIt was milled out from a piece of 20mm delrin on our CNC milling machine. I exported the board outline from diptrace and used that to create the box design in illustrator and then converted it to CNC cut files in CamBam Studio.
ESP8266 Module, PCB files - Page 1
Forum section: electronics / projects

author: ali_asadzadeh
author_rank: Super Contributor
timestamp: May 11, 2020, 07:33:21 am
content: Hi,I want to integrate the ESP8266 into my Design, Now I'm using ESP-12F module, But since I want to make a production, I want to know if we have an opensource project that has the PCB files for the chip, so I can integrate it into my PCB and save some space and production prices!
ESR Meter - Page 1
Forum section: electronics / projects

author: Flump
author_rank: Frequent Contributor
timestamp: March 18, 2014, 10:49:39 am
content: Hi AllI would like to build my own Analog ESR meter which is able to check caps in circuitor make an addon I can use with one of my Analog multimeters.Does anyone have any basic/simple schematics for one ?

author: Harvs
author_rank: Super Contributor
timestamp: March 18, 2014, 11:10:15 am
content: https://www.eevblog.com/forum/projects/5-transistor-esr-meter-design/msg171364/#msg171364

author: kripton2035
author_rank: Super Contributor
timestamp: March 18, 2014, 11:52:43 am
content: plenty of schematics to choose from on my repository :http://kripton2035.free.fr/esr-repository.html

author: w2aew
author_rank: Super Contributor
timestamp: March 18, 2014, 01:49:26 pm
content: Quote from: Harvs on March 18, 2014, 11:10:15 amI really like the simplicity and elegance of Jay's 5-transistor meter shown in the thread above.FWIW - here's a video I did on the ESR meter that I built in 2006. Although, I'm thinking I'll build one of Jay's 5 transistor units too - very cool.
ESR meter : ELV ESR-1 documentation translated to English, for anyone interested - Page 1
Forum section: electronics / projects

author: JeanF
author_rank: Regular Contributor
timestamp: September 07, 2018, 03:34:25 pm
content: Hello,these days I was doing a bit of googling about ESR meters, they seem to be quite popular everywhere. There are plenty of options, many interesting designs and discussions here on the forum, and also quite a few options for commercial units or kits to buy...By the way, many thanks to Kripton2035 for hisrepository, not only about ESR meters ; many cool projects to browse.Anyway, I was looking at the model ESR-1 from ELV (here), they provide a user manual (here) but it is only in German, and I don't speak German. The schematic and BOM are probably enough for many people on this forum, but I was curious to see what they had to say about this circuit. There are PDF translators out there, but the ones I tried gave bad results due to PDF page layout ; somes blocks of text were missing and the text was scrambled.After a bit of effort I put together a quick translation of it. You can find ithereNothing revolutionary, but it may be interesting for someone ; and it includes assembly instructions so that could be useful if anyone wants to buy and build this kit.I know there have already been many discussions about ESR meters, and I've read many different opinions ; some people swear by them, others hate them, others prefer proper LCR meters, others prefer capacitance bridges... So in order to leave this post open to discussion, what are your favourite tools or techniques, about finding faulty capacitors in consumer electronic devices ?Feel free to comment.Thanks,JF

author: hugo
author_rank: Regular Contributor
timestamp: September 07, 2018, 04:59:44 pm
content: Hi,Another ESR meter/component tester, that they sell is (KT200).Does ELV ship internationally?Thanks

author: JeanF
author_rank: Regular Contributor
timestamp: September 07, 2018, 06:20:05 pm
content: They ship at least to other european countries, as listedhere, but as you will see, shipping is quite cheap for Germany, OK-ish for zones 1 and 2, but gets reeeeaaaally expensive for zones 3, 4 and 5. (I bet they don't ship many orders to Croatia...)Canada is not mentioned but it might be worth it to ask them by email... or maybe use a reshipper from Germany if you really need to

author: kripton2035
author_rank: Super Contributor
timestamp: September 07, 2018, 06:51:56 pm
content: Quote from: hugo on September 07, 2018, 04:59:44 pmI've already shipped elv esr meter to the US for some eevblog member. shipped to me and then to the US.elv does not ship outside europe (at least they did not at the time)

author: kripton2035
author_rank: Super Contributor
timestamp: September 07, 2018, 06:54:24 pm
content: JeanF, are you OK to put your english translation on my repository ?

author: JeanF
author_rank: Regular Contributor
timestamp: September 07, 2018, 07:40:49 pm
content: Yes, of coursethank you again for all the effort you put in maintaining this repository, it is a very useful resource
ESR meters & component tester: one spreadsheet to summarize/update all threads - Page 1
Forum section: electronics / projects

author: lisafig
author_rank: Contributor
timestamp: January 26, 2019, 04:57:52 pm
content: Like probably many users, I got lost while trying to find some informations about ESR meters (and component testers)There are just too many outdated information spread throughout the years and crazy long threads.So I created a table to try to summarize some point but I'm just lost.Every little contribution to improve it is welcome. No sign-in is required, but if you master the topic and you are ready to watch and filter the user's input, don't hesitate to take the ownership of it (the users will ask you to edit it).https://docs.google.com/spreadsheets/d/1rPS_IGrx5Mb8YCJV1efvbXw0whv1zEn_HW98xHTFB1E/edit?usp=sharing
ESR of a boost converter output capacitor - Page 1
Forum section: electronics / projects

author: Mat219
author_rank: Contributor
timestamp: January 28, 2020, 08:04:46 pm
content: Hi.I'm trying to design a 200V boost converter for nixie tubes based on this schematic :https://threeneurons.wordpress.com/nixie-power-supply/hv-supply-kit/But i don't know if my output capacitor will be good for the job. Is the capacitor ESR important for a boost converter design? And what are the effects of it?Thanks for your time everyone.

author: Dmeads
author_rank: Regular Contributor
timestamp: January 29, 2020, 06:43:33 am
content: With only 5W of output power, it shouldn't be a super bad issue, but still something to take into consideration. I was building a 300W Boost converter where ESR was a HUGE deal due to output ripple current and power dissipation. (I blew up more than a few capacitors haha).I dont believe ESR will effect the output voltage much (may cause a little ripple), but it could effect the current more.These tutorials were a great help to me:https://www.powerelectronicsnews.com/technology/the-dc-dc-boost-converter-power-supply-design-tutorial-section-5-1some of stuff went over my head but some really did help me. Maybe it can help you out too.What I would do I calculate the ESR of your cap, then throw it in a SPICE simulator, and model it with the calculated ESR and other values. I can help you if you have LTSPICE or TINA-TI or PSPICE. See what happens at the output.To calculate ESR, you have to look at the datasheet of your cap. If it is electrolytic/aluminum, it might have the ESR listed, if not, look for the "tan(δ)" parameter. This is called the dissipation factor or DF. Then calculate ESR from this link:https://www.illinoiscapacitor.com/pdf/Papers/impendance_dissipation_factor_ESR.pdflet me know what happens. you can send a message if needed cuz i dont check the beginner forum a whole lot

author: Mat219
author_rank: Contributor
timestamp: June 11, 2020, 12:24:35 pm
content: Thanks for the help.I tried putting 10 ceramic capacitors in parallel at the output and if my simulation is correct, then it should be able to handle somewhere around 30W-50W at like 80-90% efficiency (Using the LT3759).Now I'm waiting for the parts to arrive and then I can start testing and hoping something doesn't blow up.

author: Dmeads
author_rank: Regular Contributor
timestamp: June 13, 2020, 04:31:55 am
content: Happy to help
ESR of ceramic caps - Page 1
Forum section: electronics / projects

author: ricko_uk
author_rank: Super Contributor
timestamp: July 26, 2020, 10:19:24 pm
content: Hi,ceramic capacitors datasheets do not seem to provide any ESR values (at least those I have been looking at).1) Why is that?2) what are some min/max/range values?Thank you

author: dmills
author_rank: Super Contributor
timestamp: July 26, 2020, 11:21:07 pm
content: They generally quote D.F. instead, but sometimes you have to hit the manufacturers part specific site for it.See for examplehttps://product.tdk.com/en/search/capacitor/ceramic/mlcc/info?part_no=C3216X8R2A104K115AE&utm_source=mlcc_commercial_soft_en.pdf&utm_medium=catalogRegards, Dan.

author: bob91343
author_rank: Super Contributor
timestamp: July 26, 2020, 11:37:14 pm
content: DF is a more relevant parameter than ESR. It includes dielectric effects and, in any circuit, the DF is the important thing.Self resonant frequency helps to estimate ESL.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: July 27, 2020, 12:04:41 am
content: ESR depends on frequency. What frequency did you want to know about?For most types, DF is fairly stable, until approaching resonance. This can be seen on the impedance plot as resistance falling at the same rate as reactance, but always staying some fraction of it (that ratio being DF).A wideband model might represent this effect with a diffusion network: a dominant capacitance with R+Cs in parallel, having geometrically spaced R and C values. (Physically speaking, these might correspond to distributed loss elements in the dielectric -- dipoles of random size and relaxation time, which happen to be distributed smoothly enough to give what looks like a constant DF. The actual physics need not bear any relation to this model though -- it's just a model, don't read into it too deeply.)Many manufacturers have databases including calculators to generate SPICE models; beware that they usually account for only a few of these effects, i.e. the model is still calculated around a frequency of interest.Tim

author: sourcecharge
author_rank: Regular Contributor
timestamp: July 27, 2020, 01:26:14 am
content: If loss tangent or tan(0) is given they are equal to DF....ESR = DF^2/(1+DF^2) * 1/(2*pi*F*C*DF)

author: ricko_uk
author_rank: Super Contributor
timestamp: July 27, 2020, 05:37:46 am
content: Thank you all, that clarifies things.
ESR of oil-filled capacitors and low frequency range of handheld LCR meters. - Page 1
Forum section: electronics / projects

author: calzap
author_rank: Frequent Contributor
timestamp: December 03, 2015, 10:36:51 pm
content: I have a couple of old 4 uF tin cans; one is a Ronken and 660 V, and the other is a EUC and 370 V. Using a DER EE LCR meter at 100 Hz, the first reads 4.1 uF and 0.8 ohms ESR, which calculates to a DF of 0.2%. Ronken specs their caps at less than 0.3% DF at 60 Hz, so it looks to be OK. The cap is labeled as containing PCB-free flammable liquid.The EUC reads 4.4 uF and 14.0 ohms ESR at 100 Hz. The DF is 3.9%. EUC (La Salle Electrical Utilities Company) is long gone, and no specs are available, but based on the Ronken specs, it appears to be bad. It probably is filled with PCBs; the former EUC factory is a superfund clean-up site because of PCB contamination. Not sure of how to dispose of it.Are there general guidelines for acceptable ESR for oil-filled caps?I'm surprised the DER EE and many other handheld LCR meters don't have measurements at 50 and 60 Hz because many capacitors are used at those frequencies. Some more expensive bench meters will get down to 50 Hz or lower. Is it that expensive to build an LCR meter that will operate below 100 Hz?Mike in California

author: calexanian
author_rank: Super Contributor
timestamp: December 03, 2015, 11:08:17 pm
content: You can look up household hazardous waste disposal on the state website and it will give you locations of disposal sites. Many of them take electronics. As for the frequency of most meters they use 100 hz, 120 hz, and 1khz. Thats because caps generally are filtering full wave or bridge rectified power and have a ripple on them of double line frequency hence 100 or 120 hz.
esr tester - Page 1
Forum section: electronics / projects

author: pete g
author_rank: Regular Contributor
timestamp: April 15, 2025, 06:46:45 pm
content: hi, i would like to construct the j diddy esr meter with short detect. is there a thru hole version of the pcb for this project?

author: moffy
author_rank: Super Contributor
timestamp: April 16, 2025, 05:33:24 am
content: You could do as the poster in this did and just use a generic breadboard:https://www.eevblog.com/forum/projects/5-transistor-esr-meter-design/msg4594744/#msg4594744

author: pete g
author_rank: Regular Contributor
timestamp: April 16, 2025, 04:07:42 pm
content: hi, i'am 88 years old and need a pcb to make any project.

author: RAPo
author_rank: Super Contributor
timestamp: April 16, 2025, 04:20:32 pm
content: The zip in thedownload on this pagehas a PCB. Is that what you are looking for?Quote from: pete g on April 16, 2025, 04:07:42 pm

author: pete g
author_rank: Regular Contributor
timestamp: April 16, 2025, 05:35:58 pm
content: hi and thanks for replying. no the project was a 7 transistor j diddy b design. he designed two versions. one had 5 transistors with no short detect. the other 7 transistors with. he never published a thru hold pcb for the 7 transistor version.
ESS ES9028Q2M mobile audio DAC full datasheet, anyone seen it? - Page 1
Forum section: electronics / projects

author: bobaruni
author_rank: Regular Contributor
timestamp: May 22, 2017, 04:03:31 pm
content: Hi all,I'm looking for the full datasheet for ES9028Q2M, the one with the I2C register maps and description and application circuit.I already have the full datasheet for ES9018K2M but the mobile ES9028 seems to be a different animal...or mineral...If it can't be posted publicly, please PM me.Thanks in advance

author: bobaruni
author_rank: Regular Contributor
timestamp: May 29, 2017, 05:08:48 pm
content: Anyone?

author: sd
author_rank: Unknown
timestamp: May 29, 2017, 07:44:07 pm
content: Try contacting ESS directly or one if its distributors. A few years ago I had to sign an NDA to get the datasheet for one of their ICs.

author: bobaruni
author_rank: Regular Contributor
timestamp: May 30, 2017, 01:39:51 am
content: Thanks, this may well be the only way to get data.
ESS monitoring device  - Page 1
Forum section: electronics / projects

author: Miti
author_rank: Super Contributor
timestamp: March 16, 2020, 11:05:35 am
content: Hi All,I’m working on making a rack for the ESS test of an electronic assembly. The rack has 8 shelves with 24 DUTs on each shelf. The supply voltage is 48V DC, current is about 5mA according to the designer, not sure about the inrush yet. The rack goes into an ESS walk in chamber and is cycled -40 C to +60 C or so for 24h.The assemblies are tested before and after the ESS and I need to monitor the power only during the ESS.Some requirements are:- Ensure the 5 mA or so was present during the entire test.- Disconnect the 48V in case an over current is detected, over current level TBD.- Indicate any over/under current event at the end of the test.Do you know any of-the-shelf device that can do this or any simple IC that I can make a small board for?Thanks!
Establishment of PC Communication with Keysight E36731A Battery Emulator via MAT - Page 1
Forum section: electronics / projects

author: Abdul.m
author_rank: Newbie
timestamp: June 16, 2025, 02:25:11 pm
content: Dear Expert Community Members,I am currently working on a project where I need to establish Remote communication between a PC and the Keysight E36731A Battery Emulator, using either MATLAB or Python. Being a Mechanical Engineer and having limited background in coding , I’m reaching out to see if anyone in the community has worked on a similar project or has resources that could help speed up the process.If anyone has already developed the full code to communicate remotely with the emulator or can point me to helpful documentation or resources, I would greatly appreciate your support!Thank you in advance for your time and assistance.RegardsAbdulResearcher, University of Cassino, Italy
Estimate delay / latency / skew on long series serial data bus? - Page 1
Forum section: electronics / projects

author: max_torque
author_rank: Super Contributor
timestamp: October 16, 2022, 05:47:26 pm
content: Im looking at a simple one way serial data link between a fair number of slave modules, up to around 64 in fact. To keep costs down, and because i require a high working isolation voltage (1kV working, 4kV peak) i was wondering about a simple optocoupler isolated serial bus, where each module has an IN and an OUT and data is passed down the chain through each module in series.If i only ever have one master device that initiates the chain of data goign down the string, then i think each module can have a hardware (ie fast!) pass on the bit type arrangement. That basically means if a bit arrives at the IN,it can be sent out the OUT immediately. Once that bit goes all the way down the chain, it'll end up back at the master if i loop the far end of the bus back into the master. Once the master has sent all it's bits, only one module will every reply (if it has a matching address) and that module can now toggle it's OUT and that data will then cascade down the bus, and eventually back up into the master?I think i'll only need a fair slow baud rate, lets say 100kbaud or something like that, so i guess depending on the hardware i use to pass forwards each bits, and knowing what the optocoupler response is, i can estimate the overall latency and potential for skew etc?Any pointers anyone ?

author: exmadscientist
author_rank: Frequent Contributor
timestamp: October 16, 2022, 08:02:01 pm
content: Sounds like isolated DMX-512 to me, you might learn a thing or two by picking over that standard.

author: max_torque
author_rank: Super Contributor
timestamp: October 16, 2022, 09:42:48 pm
content: Im thinking of using Plastic Optical Fibre as the network medium, which makes the HV isolation bit very easy. There are COTS POF transmitters and receivers available:https://i-fiberoptics.com/fiber-optic-leds.phpThese are easy to use and cheap to connect, simply requiring a cut POF to be inserted in each TCVR or RCVR.If the bus is linear and one way, then a simple logical hardware circuit can pass any RX bit straight to the TX, so cascade a bitstream down the chain of modules, and eventually back to a reciever device on the master. Any slave that matches can then respond and it's response will cascade down to the master.This has the advantage of not requiring any power transmission or isolation for the bus, as each slave already has it's own local power source and ground reference.The overall trip latency probably doesn't matter that much as long as the edge delays and rise/falls are reasonably symetrical to prevent the bits getting skewed as they travel down the chain.Downside is any failure in any slave kills the entire network though....
Estimate inductance of core with roof shaped gap  - Page 1
Forum section: electronics / projects

author: Miyuki
author_rank: Frequent Contributor
timestamp: May 30, 2023, 12:31:49 pm
content: Hi folks,is there any simple way of determining inductance roll off for a core with roof shaped gap (as in the picture)?Or do I need to make a complete simulation or an entire physical measurement?

author: T3sl4co1l
author_rank: Super Contributor
timestamp: May 30, 2023, 02:59:10 pm
content: This might be helpful,https://www.pes-publications.ee.ethz.ch/uploads/tx_ethpublications/10_A_Novel_Approach_ECCEAsia2011_01.pdfbut you'll need a different transform for the geometry shown, if it really is like that.Generally speaking, effective area goes up with gap. You can imagine adding the gap to the diameter of the center peg, and using the corresponding area. This implies flux spreads out in the area of the gap, which is true, but the total effect is more complex. For a single winding inductor filling the winding area, some of the winding intercepts the reduced magnetization within the fringe (that is, it's no longer looped around the full N*I seen by the core, but a fraction of it). Thus two things happen: 1. those turns are effectively not as closely coupled to the rest of the winding, and 2. the flux density seems to go down, or Ae goes up.Note that I must be careful describing this, because the total field seen by a turn of wire near the gap is incredibly dense and complex: it is subject to the full skin, proximity and fringing effects of the region. There is no more strenuous location in the coil. The actual magnitude of field strength might not even be too crazy, but it changes rapidly with position i.e. is very inhomogeneous and thus induces eddy currents in even very fine strands (which is how proximity and fringing effects manifest). I refer to N*I above, to invoke the equivalent magnetic circuit; effectively some turns are on a parallel path, partly decoupled from the rest; this isn't to say the field strength at the turns/strands is necessarily more or less than it is elsewhere.So, as a very basic / rough approximation, you could say Ae goes up by the apparent ratio of areas, by adding gap to the radius of the center peg; this gap dimension will be further modified by the geometry of the non-planar gap; and further still, it'll all depend on turn position within the window, which is to say A_L apparently varies by location, or the turns have some coupling factor k slightly less than 1 between them, or L = A_L N^(2-x) for some small x > 0, or etc.If you need to design more accurately than say 20% of actual saturation, you'll need a simulation or measurement.Tim

author: Conrad Hoffman
author_rank: Super Contributor
timestamp: May 30, 2023, 03:23:29 pm
content: Maybe try student edition of Quickfield-https://quickfield.com/
Estimate JFET pn junction area from datasheet or spice values - Page 1
Forum section: electronics / projects

author: matthuszagh
author_rank: Frequent Contributor
timestamp: December 17, 2022, 05:21:32 pm
content: I'm designing a circuit that may expose JFETs to very brief high power pulses. To ensure reliability, I'd like a way of modeling failure rates as a function of power and pulse duration. I'll test everything, of course, but I'd like to start with a rough theoretical model to restrict the testing. This paper (https://ieeexplore.ieee.org/abstract/document/4325054) provides a simple model of failure for power/time combinations. It only requires pn junction area as an input.I have not been able to find junction area information in datasheets. And I don't think it's embedded in the spice models either, though I could be wrong. Is there a way of estimating this from provided values, without simply asking the manufacturer? For instance, maybe it can be estimated from input capacitance values?Also, if anyone knows of resources (more recent perhaps) on semiconductor failure modelling from very short (sub microsecond), high power pulses I'd be very interested to know of them.

author: Kleinstein
author_rank: Super Contributor
timestamp: December 17, 2022, 05:27:36 pm
content: The classic Fairchild AD-6609 has drawings with dimensions for the classic US JFET types. The gate capacitance should be a reasonable good proxy for the area. However the DS values are sometimed given for different conditions - so not all numbers are directly comparable (capacitance with 0 voltge is quite different than the capacitance at -5 V).

author: matthuszagh
author_rank: Frequent Contributor
timestamp: December 17, 2022, 05:37:53 pm
content: Quote from: Kleinstein on December 17, 2022, 05:27:36 pmOh this is great, thanks! FYI for anyone else coming across this I think that should be "AN-6609".
Estimate power consumption - Page 1
Forum section: electronics / projects

author: the_eagle
author_rank: Contributor
timestamp: December 01, 2018, 02:58:01 pm
content: I have a symmetrical OTA as shown in the image attached. At a high level we can consider it similar to an op-amp so golden rules apply.The current source (I_ref) generates a supply of 100uA from 5V and V_b is 1.55V. If the output is 2.5V (the midrail voltage) in open loop configuration with input 2.5V and 2.497V for V+ and V- respectively. How can I estimate the power consumption of the device?Using the golden rules, we know that there is no input current in the op-amp input terminals; but then I get stuck on how to combine power dissipated by the current source and V_b.

author: Wimberleytech
author_rank: Super Contributor
timestamp: December 01, 2018, 06:44:46 pm
content: Here you go. Vb does not cost anything if you design it as I have shown.

author: the_eagle
author_rank: Contributor
timestamp: December 02, 2018, 11:34:18 am
content: So those extra 550uA (650uA - Iref) are taken from the power supply of Iref, is it correct?

author: Wimberleytech
author_rank: Super Contributor
timestamp: December 02, 2018, 12:22:09 pm
content: If Iref is not sourced from Vdd, then the total Vdd current is 550 ua

author: the_eagle
author_rank: Contributor
timestamp: December 03, 2018, 01:54:42 am
content: I understood the reasoning process! Thank you very much!
Estimating amplifier bandwidth - Page 1
Forum section: electronics / projects

author: nickm
author_rank: Regular Contributor
timestamp: November 29, 2014, 07:29:42 pm
content: Is there a easy way to approximate -3dB bandwidth of a common collector amlifier? I'm trying to drive a 50 ohm load at 1MHz and with the current configuration it is barely able to do so. I'd like to improve it but i'm trying to figure where to begin. My guess is there is a capacitance either from b-c or b-e which, combined with the load will have the most effect on the bandwidth.In my circuit the resistors with value {R} are 1k, and all the other components are as indicated. +v = 15V, -v = -15. The actual bandwidth is about 5MHz, so it'd be nice to have a rule of thumb which could get within around +/-50%.

author: Zero999
author_rank: Super Contributor
timestamp: November 29, 2014, 07:37:38 pm
content: It's an emitter follower so there will be some loss.The first thing which strikes me is it's configured in class B so there will be some cross over distortion. Bias it into class AB and it should improve.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: November 30, 2014, 02:08:34 am
content: Schottky bias diodes???Is the source well and truly zero ohms? Or do you have ESR parameter set? That's one of the things I hate about LTSpice, you share a schematic and the readers are left guessing about everything.An emitter follower will work up to fT or so, but the source is only going to drive up to f_o ~= 1 / (2*pi*Zo*2*Ccb). At that point, bias current will also start ratcheting up, because the diodes start rectifying the signal source and dumping DC across the bases. (If you add the capacitors, you'll see your circuit bears a striking resemblance to the full wave voltage doubler circuit.) Big capacitors across each diode (or using resistors instead) helps.Tim

author: dannyf
author_rank: Super Contributor
timestamp: November 30, 2014, 02:42:41 am
content: QuoteIt is an emitter follower (=current amplifier). So if it is only 1Mhz, the issue is somewhere else, like super-high source impedance.