hybridfree/eevblog-posts huggingface dataset:
FreeCAD Object / Material Manipulation - Page 1
Forum section: electronics / general

author: KungFuJosh
author_rank: Super Contributor
timestamp: January 05, 2025, 06:13:14 am
content: I'm not great with CAD. I've done some stuff from scratch, and modified other objects, but this one is being a pain in the ass. I want to change the material for specific parts of this model, but no matter what I've tried, it will only change the entire model.I tried different modes, including trying to split parts, but nothing works for me. I want to make the metal pieces look like metal, and leave the rest plastic. What am I doing wrong, and what should I be doing?Thanks,Josh

author: KungFuJosh
author_rank: Super Contributor
timestamp: January 05, 2025, 07:07:33 pm
content: For anybody else wondering, the issue is that it's an STP file, so one way to do it (very tediously) is to go to Part mode, and then use "set appearance per face." It's a pain in the ass, but it basically works.ETA: However, despite that making the step file look the way I wanted, it wouldn't work in Kicad for some reason. 🤷Thanks,Josh

author: Zoli
author_rank: Frequent Contributor
timestamp: January 06, 2025, 06:24:47 am
content: It shows in the footprint properties, and not on the board? If both yes, in 3D view mode under "Appearance"(right side) check the "Models not in POS File" line.

author: MarkF
author_rank: Super Contributor
timestamp: January 06, 2025, 02:48:02 pm
content: I don't know what you mean by "set appearance per face".Here is what I did with FreeCAD:Opened the STP file.Expanded the tree on the Model tab.Right click on 'SOLID' and select 'Appearance'.Change the color of everything (set the color of the body).Right click on 'SOLID' again and select 'Set Colors'.Select all of the metal faces (click on first and CTRL-click additional).Change the color to a light gray for steel.Select and export 'SOLID' as a STP file.I eliminated 'COMPOUND' since it is just a few reference lines.This works fine for use in DipTrace. I don't use KiCAD.
Using EasyEDA & LCSC for parts. Adding BOM to LCSC cart - Page 1
Forum section: electronics / general

author: axeonic
author_rank: Contributor
timestamp: February 04, 2025, 03:13:19 am
content: Hello, thanks for reading my question. I'm trying to add my BOM parts to my cart in LCSC. I click "add to cart", a message box pops up with two input fields; "Include" and "Add to". The "include" field is empty, the "add to" field contains my cart# as seen in the attached image.When clicking on the "include" field, nothing is displayed and I can't just click on the "Add" bottom at the bottom right. What goes in that "Include" box?Sincere thanks for any help,Tony
Adjusting PCB layer thickness for short return path - Page 1
Forum section: electronics / general

author: newtekuser
author_rank: Frequent Contributor
timestamp: November 01, 2024, 03:49:25 pm
content: I need some input on the values chosen for me by KiCad on my 4 Layer PCB setup. My goal is to bring the ground planes closer to my signal and power planes to have a good short return path. Are the suggested values for thickness good?

author: tggzzz
author_rank: Super Contributor
timestamp: November 01, 2024, 04:15:37 pm
content: Quote from: newtekuser on November 01, 2024, 03:49:25 pmYour PCB fabrication house will specify the stackup(s) they can make. Use those figures.

author: Kurets
author_rank: Regular Contributor
timestamp: November 01, 2024, 04:17:26 pm
content: Unless you are buying large quantities of PCBs it is unlikely that you can specify the layer stackup freely. Go to your preferred supplier JLPCB, WE Direkt, etc. and look what their standard stackup for a 4-layer board is.In any case, just having ground/vcc on inner layers will be good enough. The only reason to care about the specific layer separation is if you are trying to do controlled impedance traces for RF or very high speed digital interfaces.

author: newtekuser
author_rank: Frequent Contributor
timestamp: November 01, 2024, 05:10:06 pm
content: Quote from: tggzzz on November 01, 2024, 04:15:37 pmI know my fabricator (JLC) can manufacture this stackup configuration because they have already produced it for me, but I was wondering if I could improve on it. Based onKurets' reply I should be good already.

author: tggzzz
author_rank: Super Contributor
timestamp: November 01, 2024, 07:41:00 pm
content: JLC can (apparently; I havn't used them) do many different thicknesses and stackups.maThe question is then why one of them wouldn't be satisfactory. If there is an answer to that, then choose another.

author: thm_w
author_rank: Super Contributor
timestamp: November 01, 2024, 08:57:21 pm
content: You choose from the list here:https://jlcpcb.com/impedance

author: jane810314
author_rank: Newbie
timestamp: December 30, 2024, 07:54:36 am
content: The layer stack-up is good for impedance 50ohm on Top layer and Bottom layer.
Long low speed traces signal integrity - Page 1
Forum section: electronics / general

author: newtekuser
author_rank: Frequent Contributor
timestamp: December 23, 2024, 07:14:01 pm
content: My 16x2 LCD is connected to the MCU using pretty long traces with the longest being 4cm. To mitigate SI issues I am using a ground pour connected to the adjacent GND plane underneath using stitching vias spaced about 1cm apart on the perimeter and along the traces.Do I even need to be concerned about this considering that when I had the LCD connected using a much longer ribbon cable, I did not encounter any issues? Being a noob at this technique I'm worried that I'm going to introduce parasitic inductance with the big pour.Attached is my layout.

author: thm_w
author_rank: Super Contributor
timestamp: December 23, 2024, 10:15:01 pm
content: Do you need to be concerned? No.But this is still a good layout, good practice, so why not.The plane will add parasitic capacitance not inductance, which won't be an issue at the low speeds the LCD is driven at.It will also shield the noise from transferring between traces (since you put space between them).https://www.protoexpress.com/blog/how-to-reduce-parasitic-capacitance-pcb-layout/

author: newtekuser
author_rank: Frequent Contributor
timestamp: December 23, 2024, 11:19:32 pm
content: Quote from: thm_w on December 23, 2024, 10:15:01 pmThank you! Meant to say capacitance and wrote inductance

author: Smokey
author_rank: Super Contributor
timestamp: December 23, 2024, 11:41:09 pm
content: properly designed ribbon cables will alternate important signals with grounds, which is about the best you can do when sending multiple signals on a cable.

author: David Hess
author_rank: Super Contributor
timestamp: December 24, 2024, 10:08:59 am
content: It will reduce the inductance and increase the capacitance, lowering the impedance of the traces. If the circuit was sensitive to impedance then this could matter, but when driving an LCD?Power consumption driving the higher capacitance lower impedance lines will be higher because more charge is being moved around. In a micropower application this could matter, but then the ground plane would be relieved as well.
PCB design feedback : buck boost and buck converter / power distribution PCB - Page 1
Forum section: electronics / general

author: louislouis
author_rank: Newbie
timestamp: December 15, 2024, 08:37:38 pm
content: Hi,I'm trying to design a 4 layer pcb with:-XL6008 based buck boost converter on one side (fixed to 12v output)-XL4015 based buck converter on the other (fixed 5v output)Keep in mind I'm a beginner and learning pcb design online as I go.I was planning of having 2 ground planes in the middle but are there other things I need to consider as the 2 converters will be really close? Will there be any interference? I have to place them on either side as the pcb will be quite small 50x80mm and I have other stuff on the buck converter side (Attiny control IC with status leds and buttons).Also I don't really know how to place the two inductors for the XL6008 buck boost converter.I have the schematics from the ICs datasheets:https://www.lcsc.com/datasheet/lcsc_datasheet_1809200019_XLSEMI-XL6008E1_C73012.pdfhttps://www.lcsc.com/datasheet/lcsc_datasheet_1811081616_XLSEMI-XL4015E1_C51661.pdfThank you for your timeUPDATE 1:So after some digging and seeing your answers I've tried fitting both converters on the same side of the board. I tried to place the components the best I could (inductors away from FB line, keeping the loops small and tight).For the buck boost I couldn't find an easy to buy coupled inductor (designing on easyEDA, buying LCSC and JLCPCB), so went for two separate inductors. I read I lose in efficiency, is that all?The input is a 3S lipo.output load is around 3A minimum for the 5V and 2A for the 12V.There is also a mosfet setup for an emergency stop between the lipo input and direct output (goes to 20A UBECs)

author: thm_w
author_rank: Super Contributor
timestamp: December 17, 2024, 09:23:39 pm
content: What voltages and currents will be used?The "two inductors" for XL6008 are coupled inductors, you can read here:https://www.coilcraft.com/en-us/edu/series/a-guide-to-coupled-inductors/I doubt the attiny will have issues, unless, you are working with analog signals, then you need to take care.

author: Kean
author_rank: Unknown
timestamp: December 18, 2024, 05:17:41 pm
content: Note that if you plan to reflow the PCB in an oven (or have it produced commercially that way), you may have problems soldering heavy components like inductors on both sides of the PCB unless they are glued to stop them falling off.

author: Pseudobyte
author_rank: Frequent Contributor
timestamp: December 23, 2024, 01:47:16 pm
content: You may want to tie the SW nodes of U2 together, might not work as drawn.
Design Solderable Breadboard - Page 1
Forum section: electronics / general

author: jpanhalt
author_rank: Super Contributor
timestamp: December 04, 2024, 06:36:45 pm
content: I like using solderable breadboards designed to duplicate plug-in variety (attachment)." alt="" class="bbc_img" />SparkFun was early in the game with a 5-hole per column design. Now there are many versions. There are also breakout boards to adapt SMD's to those breadboards. I am thinking of getting a small batch of custom breadboards made that incorporate pads and connections for SMDs to the common 5-hole per column design. I came up with 5 common SMD packages (attachment) that will fit in the 0.3" empty space in the board. Unpopulated, they would not interfere with anything on top.Here are the 5 I have picked:Are there any others you would add?

author: jpanhalt
author_rank: Super Contributor
timestamp: December 12, 2024, 11:18:12 am
content: Version 2Here's my second roll:Changes and rationale:1) First version was basically a non-dimensioned sketch. In second version, drill size is 0.04" to accommodate 0.025" square pins.2) Pads changed to square to fit SMD passive sizes 805 and 1206 (examples shown) better. Round pads also work, and I routinely use both sizes when convenient on my breadboards. The square pads may facilitate reflow, but there is the hole to worry about.3) Bottom tract connecting pads is increased 0.04".4) Increased number of SOT23 and compatible footprints to 15 (six -3 and nine -6); SOIC-8 are 3 and eliminated the higher power -3 footprints because fit was tight.The SOT23 and SOIC-8 are the two most common sizes I need to add to MCU designs. Of course, there are others, but there are so many versions of them that adapter boards are probably the best solution.Any comments? I am getting ready to send off a smaller version to see how it works.EDIT: It's ordered (capture). I cut it in half just as a test to save money.
Active Antenna RF Design - Page 1
Forum section: electronics / general

author: rayan
author_rank: Newbie
timestamp: January 21, 2025, 09:18:00 am
content: I am currently designing a coplanar waveguide (CPW) structure for the attached circuit. In the past, I created a CPW structure for a passive antenna using FR4 material for the PCB, which has a dielectric constant of 3.48. The PCB thickness was 0.5 mm, which I used as the distance between layers, with the second layer serving as the reference ground plane. For that design, I calculated a 1 mm RF signal width and a 0.2 mm clearance from the ground using an online calculator. However, I am encountering difficulties applying the same approach for an active antenna due to differences in the designI am attaching the schematic for the circuit I am designing on the PCB, as well as the coplanar waveguide (CPW) structure I attempted. It appears that the CPW structure may not be designed correctly .I am seeking advice on the optimal component placement for this circuit to ensure the best performance, particularly for components such as the ferrite bead, capacitor, and resistor in the RF signal path. Additionally, I would appreciate guidance on how to properly route traces. I am a beginner in circuit designing and PCB design, so any help or suggestions would be greatly appreciated
Designing PCBs for HV applications upto 6kV - Page 1
Forum section: electronics / general

author: fracton
author_rank: Contributor
timestamp: December 07, 2024, 02:21:35 am
content: I've been trying to build HV pulser for one of my experiments. After a lot trials I finally got one of Behlke's a MOSFET based switch (HTS-61-03-C). I am trying to design a PCB to mount this switch, an AC-DC converter to get +5V to power the switch and connections to mount the SHV mounts for HV input/output.I know Altium and Eagle have in-built features for the same, however I have no direct access to these software. So, I am trying to design it using easyEDA or KiCAD but have no prior experience in designing boards for HV applications.Can anyone comment on implementing the creepage and clearance rules needed for HV PCBs using easyEDA or KiCAD.Also, here's the drawing for the switch :https://www.behlke.com/pdf/drawings/compact_series_79x38x17_single_drawing.pdf

author: Slh
author_rank: Regular Contributor
timestamp: December 08, 2024, 06:06:04 pm
content: For Kicad have a look at this link:https://forum.kicad.info/t/introducing-kiclearance-to-auto-generate-clearance-rules-from-a-simple-table/51706/1It's a clearance rule generator. You make a table with all your net classes and just define the distances between them. then run the script and it will generate all the rules that Kicad needs. It's only clearances though. It won't recognise that a slot may fix creepage issues.
Importing Allegro .brd file in Altium - Page 1
Forum section: electronics / general

author: Spargus01
author_rank: Newbie
timestamp: October 12, 2024, 11:37:50 am
content: Hi everyone,I need to import a reference design created with Allegro 16.6 (.brd file) into Altium. I initially tried importing the .brd directly, but it fails because Altium requires an installation of Allegro for the process (which I don’t have). I understand Altium can import Allegro files in .alg (ASCII) format, but converting .brd to .alg still requires Allegro and its extracta tool. After searching online, I couldn’t find any method to make this conversion, not even via intermediate ECAD tools (e.g., KiCad).I also tried opening the file with Allegro Free Physical Viewer, but it gave an error saying the .brd file was saved in an older, unsupported version and needs to be updated using DB Doctor—a tool only available with an Allegro installation.Are there any other ways or tools I could try to get this .brd file into Altium?Thank you!

author: Ice-Tea
author_rank: Super Contributor
timestamp: October 12, 2024, 11:42:43 am
content: Register for a free Allegro trial ;-)

author: nctnico
author_rank: Super Contributor
timestamp: October 12, 2024, 01:20:06 pm
content: If you PM me, I could give it a try as I'm an Allegro user. I have to warn though that converting designs from one package to another is prone to (subtle) problems.

author: Spargus01
author_rank: Newbie
timestamp: October 12, 2024, 02:59:13 pm
content: Quote from: nctnico on October 12, 2024, 01:20:06 pmThank you, I just PM you.

author: phitastic
author_rank: Newbie
timestamp: November 17, 2024, 09:02:20 pm
content: Quote from: nctnico on October 12, 2024, 01:20:06 pmHi nctnico,I'm facing the same challenge as Spargus01 above-- trying to move an Allegro 16.6 .brd over to Altium, but learning about the need to have an "extracta" tool available. Would you be willing to help me as well? I'm a new user, so suffering from the "no PMs before 10 posts" issue, but if you are able to send me a PM, I'd love to connect. Thank you
Altium - footprint reuse - Page 1
Forum section: electronics / general

author: 16bitanalogue
author_rank: Regular Contributor
timestamp: November 30, 2024, 02:03:55 am
content: I am getting back into the swing of things - having to create my own footprints since I do not have a librarian. I have posted several questions before, so I am in need of your training again.I am creating footprints for the UAL series of power resistors:https://riedon.com/media/pdf/UAL.pdfI created one footprint already for the UAL25-1RF8 from scratch and it is now placed to my PCB. My steps are as follows for full discloser of how I am adding schematic components and footprints since I have no official training. Google and this forum are my training.1. Find component in the Manufacture Part Search tab then save to my Workspace.2. Search for the same component in the Component tab and Edit part3. Under Add Footprint I select New Footprint.4. Save, Release, and then have to go back into my Schematic to delete the schematic component symbol and add it back for the schematic symbol to link to my new footprint.The rest of the resistor series are the same footprint size (UAL25 series), and I would like to believe I would be able to add the footprint I just created to be added to the next resistor from the schematic:1. select component properties2. add footprintI cannot do this as 'Add Footprint' is greyed out.Certainly, I can redo all my steps by searching for my new component in the Component tab, editing the part, and pasting the footprint from the previous component I updated.I tried Footprints Manager, but the option to select 'use Footprint from component library xxxxx" is greyed out as well.Using the browse menu doesn't seem to find the name of the footprint either UAL25-1RF8-Footprint-1 in my case.Can someone help point me in the right direction? Or do I need to follow the steps outlined above every time if I want to reuse a footprint? That works, but it's some work.

author: thm_w
author_rank: Super Contributor
timestamp: December 02, 2024, 11:01:54 pm
content: You should probably watch a tutorial on libraries and part creation.https://my.altium.com/altium-365/getting-started/creating-new-componentIt sounds like what you are trying to do is create parts on the PCB directly? What you want to do is create them in a library, make a new schematic and PCB library, then drop them on the schematic from that library.Altium forum is here:https://www.eevblog.com/forum/altium/
SOLVED Change outside pcb dims from Gerber file ? .BRD need help  - Page 1
Forum section: electronics / general

author: Overspeed
author_rank: Frequent Contributor
timestamp: November 11, 2024, 04:04:33 pm
content: HelloI have a set of gerber files for single and twin AD8221 amplifier , but the original outside PCB shape is really small / narrow .Does it is possible to increase the outside dims from a gerber file ( to 50x50mm) ? I have tried with Dimtrace but that generate an mystery offset between the new outside shape and the oldest one?I have also the .brd file but I have not EAGLE , I link the .brd I haveRegardsOS

author: Kean
author_rank: Unknown
timestamp: November 11, 2024, 11:36:52 pm
content: I don't understand the problem. Can you try explain better, or show us a picture?Attached is what I see when opened in Eagle.

author: Kean
author_rank: Unknown
timestamp: November 11, 2024, 11:43:35 pm
content: Ah, maybe this is what you want... I changed the dimensions to a 30mm square. 50mm is possible, but a lot of empty space.

author: Kean
author_rank: Unknown
timestamp: November 11, 2024, 11:46:13 pm
content: Just for reference if anyone else is interested, this is the designhttps://github.com/HMS-RIC/EMG-EEG-Amplifier

author: Doctorandus_P
author_rank: Super Contributor
timestamp: November 12, 2024, 01:38:42 am
content: It looks like a complete eagle project, with both a schematic and a PCB file.If you don't have eagle anymore, the eagle importer for KiCad works quite good.

author: Kean
author_rank: Unknown
timestamp: November 12, 2024, 01:43:48 am
content: Yes, the Eagle schematic and board files are available on the github repo.But they are not consistent. The capacitor values are different between schematic and PCB. Something to watch out for.

author: Overspeed
author_rank: Frequent Contributor
timestamp: November 12, 2024, 06:48:20 am
content: Quote from: Kean on November 11, 2024, 11:43:35 pmHelloFirst great thanks for your answersYes that the thing I want , I need 50mm x 50 mm for a mechanical problem as my enclosure / screw system need 50x50 , I plan to launch some in fabrication by using PCBWAY so as far that under 99x99 mm price is the sameYes that a old Github , I agree for the cap value but capacitor value are not really important as I need a demo / eval board to compare some AD82XX between themI usually design my PCB by using Autocad and convert in Gerber I am far to be an expert in CAD PCB , but I will learn Kicad which a good solution.RegardsOS

author: Overspeed
author_rank: Frequent Contributor
timestamp: November 12, 2024, 08:56:45 am
content: HelloSolved , great thanks to KeanRegardsOS
Request for Recommendations on ESP32-C3-MINI-1-N4 Schematic and PCB with LiPo Ch - Page 1
Forum section: electronics / general

author: achraffff
author_rank: Newbie
timestamp: October 31, 2024, 08:44:30 pm
content: Hello everyone,I’m working on a project using an ESP32-C3-MINI-1-N4 module. Here is the first version of my schematic and PCB for this project. The design includes:- An ESP32-C3-MINI-1-N4 for WiFi/Bluetooth connectivity,- A charging circuit based on the TP4056 for a LiPo battery,- A 5V to 3.3V power conversion using an MIC5205-3.3 regulator to power the ESP32.I would appreciate your feedback and recommendations on the following points:1. The layout of the components and trace widths, especially for power lines.2. The management of LiPo battery charging and discharging to prevent any risk of overcharging or over-discharging.3. Any suggestions to improve the efficiency and stability of WiFi/Bluetooth connectivity, considering the use of the onboard antenna.Thanks in advance for your insights and advice!
Stitching multiple copper pours on the power plane to GND planes - Page 1
Forum section: electronics / general

author: newtekuser
author_rank: Frequent Contributor
timestamp: October 30, 2024, 12:24:16 am
content: I have the following 4 layer stack-up and would like to stitch the copper pours for different voltages I have on the PWR plane to the ground planes. Each copper pour on the PWR plane has its own shape and does not cover the entire area of the PWR plane.The two GND planes are continuous and cover the entire area of the PCB.L1: SIGL2: GNDL3: PWR (with copper pours for 5V, 3.3V, 12V)L4: GNDWhat would be the best course of action for stitching these copper pours to the GND planes?A. stitching VIAs around the perimeter of each copper pourB. stitching VIAs around the perimeter of componentsC. stitching VIAs filling each copper pourD. something else (please advise)I'm thinking of spacing them like 5-10mm apart and go with option A.

author: Doctorandus_P
author_rank: Super Contributor
timestamp: October 30, 2024, 02:32:19 am
content: Robert Feranec has posted some pretty good video's which also so field simulations of what happens inside a PCB when signals change their GND reference to another layer. He has made several video's about this topic, so I can't recommend a single one, but they are easy to find.

author: newtekuser
author_rank: Frequent Contributor
timestamp: October 30, 2024, 04:01:38 am
content: Quote from: Doctorandus_P on October 30, 2024, 02:32:19 amFound it!
Altium Import Helper - Page 1
Forum section: electronics / general

author: Crossphased
author_rank: Regular Contributor
timestamp: September 29, 2024, 05:51:43 pm
content: Do you use UltraLibrarian symbols/footprints? If so this script is for you. The UltraLibrarian provided import script is a pain in the butt, you can only import one symbol at a time, and you have to unzip the file first.What this script does:Imports EDA files:Unzips UltraLibrarian and SnapEda filesExtracts IntLibs to source SchLibs and PcbLibsImports UltraLibrarian text filesImports SchLibs and PcbLibsplaces source zip files in Archive dirImproves aspects of the symbols and footprints as described belowProcesses Symbols in SchLib:sets the pin font and size to constants defined below: PIN_FONT_NAME, PIN_FONT_SIZEsets active low pins so an overbar is in schematic symbol on pin namefilters symbol parameters, deletes many unecessary params, see 'FilterComponentParameters' method to editsets symbol body to color defined in constant below, COLOR_SYMBOL_BODY_FILLsets symbol body outline to color defined in constant below, COLOR_SYMBOL_OUTLINEsets all text label objects to constant: DEFAULT_FONTchanges all lines in symbol to color bluemoves component so pin1 is at the origin, including for multipart sch symbolsfixes UltraLib footprint previewsmakes MFR Part # visible, at bottom left of symbol body, including for multipart sch symbolsdeletes default schematic symbol Component1Processes Footprints in PcbLib:deletes default footprint PcbComponent1changes silkscreen pin 1 indicator of '*' to filled circlechanges Mechanical Layer13 pin 1 indicator of '*' to filled circlechanges linewidth of Mechanical13 Layer from 1 mil to 2milautomatically maps STEP files for SnapEDA footprintsGithup repo:https://github.com/johnpolakow/Altium_Import_Helper
PCB at home with resin 3d printer - Page 1
Forum section: electronics / general

author: panoss
author_rank: Frequent Contributor
timestamp: September 17, 2024, 05:53:57 pm
content: I 'm thinking of buying a resin 3d printer for homemade PCBs] (for when I need a prototype NOW):I suppose some of you do it, so I wanted some advice:1. is this a good thought?2. which printer? I m thinking aboutPhoton Monkey X 6Ks, around 170$.

author: Doctorandus_P
author_rank: Super Contributor
timestamp: September 17, 2024, 08:12:04 pm
content: Quite a nice idea, and I wonder why I had not thought of that myself. It's probably because I am not interested very much in resin printers and th cost and (probably) short (a few years) shelf life of the resins. But the results do look usable. But still, I would prefer to use a CNC machine with a laserMarco Reps uses a Cetus3D printer for this, but you can put a laser into almost any X, Y, (Z) gantry type contraption. And if it's sturdy enough, you can also use it to drill the holes for the THT parts.

author: panoss
author_rank: Frequent Contributor
timestamp: September 17, 2024, 08:19:31 pm
content: Quote from: Doctorandus_P on September 17, 2024, 08:12:04 pmWhy?Is this because, as you say, you can also use it to drill the holes?

author: Doctorandus_P
author_rank: Super Contributor
timestamp: September 17, 2024, 08:43:11 pm
content: Yes, partly, but also because resin printers are just not the thing for me as I already wrote in my previous post. So, if you already have a resin printer, then of course, give this method a shot, but buying a resin printer just for using it for this would seem a bit short sighted, and you should have a broader look at other options (such as the laser I mentioned) too.Also, dry film is probably not the best for occasional use. As mentioned in the video, it's difficult to work clean enough to get good results. the lasered results from the Marco Reps video look a lot better. And I also guess it's easier to get reliable. A dead pixel on your resin printer could easily become an opened trace. A part of Marco Reps getting better results may be because of thepre-sensitized PCB's he is using.

author: rhodges
author_rank: Frequent Contributor
timestamp: September 18, 2024, 12:29:03 am
content: I did not watch the video. Does it show how to make a solder mask after etching the board? I am working with SMD now, and without a solder mask, my boards would be useless with solder bridges I can not fix.

author: coppercone2
author_rank: Super Contributor
timestamp: September 18, 2024, 01:57:23 am
content: you could do a dry film but alignment is the problem you need indexing added to your 3d printer

author: Warhawk
author_rank: Frequent Contributor
timestamp: September 26, 2024, 05:52:00 pm
content: from the video: "tracks are 0.3mm and turned out great.."-> No, they didn't. The quality is terrible. And I am saying this as a someone who has been doing home-made PCBs for a decade.Thank's god I can order now cheap PCBs from local vendor (Aisler).
new UltiBoard 4.x to KiCad converter - Page 1
Forum section: electronics / general

author: MastaTabs
author_rank: Newbie
timestamp: September 21, 2024, 10:52:05 pm
content: Hi everyone,This is actually my first post...I’ve been reading this forum for quite a while, but I never registered until now because I finally have something to share.I created a new converter that I think some people in the community might find useful.I had some old UltiBoard designs that I wanted easier access to, so I went ahead and made this converter.If you want to try it, I’d love to get your feedback. And if you'd like to contribute, you're more than welcome to participate.This is only for DDF files, as the UltiCap schematic format, unfortunately, isn't documented to my knowledge.Here’s the link to my GitHub:https://github.com/MastaTabs/ulti2kicadHave fun!
Schematic Review of Portable Air Quality Monitor (nRF5340 based) - Page 1
Forum section: electronics / general

author: MrSplike
author_rank: Newbie
timestamp: September 15, 2024, 05:31:35 pm
content: Hello!This is the first completed revision of my portable air quality monitor project, just the schematic for now. I posted an earlier version of the power subsystem a couple months ago, and finally got around to finishing the rest of it.This will be for a school project, so feel free to be as nitpicky as possible, I'm learning a lot from this project.All of the DNP parts are stuff I already have and will be assembling by hand.Thanks! Schematic below:https://imgur.com/a/7sp3V6y

author: thm_w
author_rank: Super Contributor
timestamp: September 16, 2024, 10:19:21 pm
content: I don't have experience with the NRF5340, but otherwise, it looks good to me.Previous posts:https://www.reddit.com/r/PrintedCircuitBoard/comments/1fc5pkq/schematic_review_request_portable_air_quality/https://www.reddit.com/r/PrintedCircuitBoard/comments/1dzgnas/schematic_review_request_power_subsystem_for/

author: Salitronic
author_rank: Contributor
timestamp: September 17, 2024, 02:41:46 pm
content: From a quick look at the schematics the one thing I would recommend is adding a pull-up resistor to the CS pin on the flash memory. All flash memory chips that I know of (this included, see page 72 of the datasheet) require that the CS pin follows the VCC voltage during power up/down and this is done by having an external pull up, since the MCU would have not yet configured the CS GPIO. Failing to do so results in the flash chip starting in an unpredictable state and you'd need to reset it before accessing it.
Are these power traces a "star topology"  - Page 1
Forum section: electronics / general

author: Dmeads
author_rank: Regular Contributor
timestamp: September 10, 2024, 06:10:59 pm
content: I am laying out my first 4 layer board (signal+power, GND, GND, signal+power).This is a hobbyist project AFE for a single lead ECG. The ADC (MCP3202) I am using calls for the power routing to be a "star configuration" and for the power traces to be at least 2 times the width of the signal traces.I have included pictures of my top and bottom layers (with and without silk screen). The top_no_silk.png has the power ports labeled.Is this power layout a "star configuration"? (I think this means every Vin has a direct path back to the voltage source -- nothing is in "parallel" so to speak)Any other tips would be helpful as well!Thank you!

author: thm_w
author_rank: Super Contributor
timestamp: September 10, 2024, 09:05:15 pm
content: You can find the layout tips on their site:https://ww1.microchip.com/downloads/aemDocuments/documents/MCU08/ApplicationNotes/ApplicationNotes/00688b.pdfhttps://www.microchip.com/en-us/product/mcp3202

author: temperance
author_rank: Super Contributor
timestamp: September 10, 2024, 10:06:17 pm
content: What you've got is a two return trances carrying some current to power the amplifier and the ADC to a common reference point and the noise across the common return paths is coupled into the ADC input.This doesn't qualify as a star GND network. The purpose of a star GND network is to avoid coupling return currents into your signal path. Your PCB layout does the opposite and promotes coupling of return currents into the signal path.A GND plane on both sides of the PCB will be a better solution as it also provides shielding for the very high impedance inputs.Maybe some common mode chokes will be required for the DC/DC converters.

author: thm_w
author_rank: Super Contributor
timestamp: September 13, 2024, 08:18:30 pm
content: Good video about star grounds for you:
Error in LTSPice simulation/Circuit  when used the biosensor as Rf - Page 1
Forum section: electronics / general

author: Zainiii
author_rank: Contributor
timestamp: September 06, 2024, 03:45:14 am
content: Hi,Hope everyone is doing great.I am building a circuit in LTSpice using the inverting configuration of the LT1028 operational amplifier. The input signal provided is 0.7 Vp, which is applied to R1 (5M ohm). For the feedback resistor (Rf), I am using my biosensor, whose impedance varies from 10M ohm to 25M ohm. The equivalent circuit of my biosensor is attached in the picture. I want to measure the value of Rf using the formula:Rf= R1 x ( −Vout/Vin)After R1, the voltage drops from 0.7 Vp to 60 uV before reaching Rf (the biosensor).I have created a separate circuit in LTSpice representing the equivalent circuit of my biosensor. The values I used for R and C in this LTSpice circuit are based on the impedance analyzer readings. The actual impedance of my sensor is 15M ohms, but I used the values of R and C provided by the impedance analyzer, where R and C are in parallel. The voltage applied to this circuit is 60 uV, but the output I obtained from the circuit is very low (around 0.8 uV), and the waveform after the circuit is not a sine wave.Given this, the impedance value for Rf that I calculated is incorrect.I have a few questions:1. Did I correctly build the equivalent circuit of my biosensor in LTSpice? If not, could someone suggest the necessary changes to the circuit?2. Why am I not getting the correct value for Rf when I use the equivalent LTSpice model? When I use a simple resistor for Rf, I can calculate the correct value using the above formula.3. Can someone explain why the LTSpice model of my equivalent circuit alters Vout and why the parallel capacitor significantly affects Vout?For reference, I will attach the picture and the LTSpice ASC file.

author: iMo
author_rank: Super Contributor
timestamp: September 06, 2024, 07:02:40 am
content: 3. because your LTspice equivalent circuit works as a band-pass at 30Hz.. The 1kHz is therefore attenuated..Without the 5Meg there it simulates as a low-pass with the knee at 30Hz, therefore the 1kHz is attenuated too..

author: iMo
author_rank: Super Contributor
timestamp: September 06, 2024, 07:21:37 am
content: 1. my equivalent circuit based on your above picture..PS: do you plan to use the LT1028 in your real circuit??

author: iMo
author_rank: Super Contributor
timestamp: September 06, 2024, 08:17:57 am
content: My thought experiments based on your above measurement method/schematics (no idea what are your eqv. biosensor's values there, but let us target "impedance" Rf=10Meg at 1kHz)..
Colour PCB cost - Page 1
Forum section: electronics / general

author: Sagar
author_rank: Contributor
timestamp: August 27, 2024, 08:11:28 am
content: I just want to know how the soldermask can be changed to coloured one and what will be the cost of PCB with coloured soldermask and silkscreen. Is there any other advantage of using colored pcb or only asthetics.

author: Doctorandus_P
author_rank: Super Contributor
timestamp: August 27, 2024, 10:15:54 am
content: Green soldermask is often the cheapest because it allows for pooling.Except for Oshpark. With Oshpark you can choose any color as long as it's purple.Black soldermask is a nuisance to see tracks on. Especially with matte black.For the rest, it's just aesthetics, except maybe when you go full color, maybe you can get something functional out of a full color silkscreen. There is at least one manufacturer that can do this.For other manufacturers, they will refuse your PCB if silkscreen covers more then 30% or so of the PCB area, I guess they think the ink is more expensive then their customers are willing to pay for.Edit: (as response to Psi below) You can also have a look athttps://pcbshopper.com/for price information. By default it has a "least expensive color" price

author: Psi
author_rank: Super Contributor
timestamp: August 27, 2024, 10:42:06 am
content: Sometimes the cost is the same for whatever mask color you pick.Sometimes there is a small charge, but it's usually not much. As an example a $50 PCB order might go up to $52 when you change from green to red mask.It just depends who is making your PCB and how they charge for it.Have a play with the PCBWay online quoting system. You can enter details and see how the price changes.I think they are free for most colors except purple and some of the Matte finish options.https://www.pcbway.com/orderonline.aspxBlack PCBs can need more cleaning after you solder them to remove all the flux marks. The black color makes flux really obvious.
MicroCap 12 - Shapes becoming distorted after restart - Page 1
Forum section: electronics / general

author: insanoff
author_rank: Contributor
timestamp: September 07, 2024, 05:03:30 pm
content: Hi folks,I'm checking MicroCap 12 and just tried to create a shape (we say symbol in LTspice language). It looked pretty good when I saved it. But when I restart MicroCap, the shapes look glitched.See screenshots of how am I doing it and the result of how it looks when I close and open MicroCap. The source code also seems fine to me.What do you think could be the problem?Code:Name=TempBlock=0,8,80,184,0,16BlockLine="Line",-16,16BlockLine="Line",-16,32BlockLine="Line",-16,48BlockLine="Line",-16,64BlockLine="Line",-16,80BlockLine="Line",-16,96BlockLine="Line",-16,112BlockLine="Line",-16,128BlockLine="Line",-16,144BlockLine="Line",-16,160BlockLine="Line",-16,176BlockLine="Line",40,200BlockLine="Line",96,104BlockLine="Line",96,88BlockLine="Line",48,-8BlockLine="Line",32,-8FColor=None
Schematic Review Portable power supply - Page 1
Forum section: electronics / general

author: Sagar
author_rank: Contributor
timestamp: August 19, 2024, 12:39:58 pm
content: I have designed this power supply unit to get 3.3, 5, 8 and 12V. So that it acts like a secondry supply to test and power small projects and mircocontroller.1) I used TP5100 as charging in 2S mode2) 5v boost up mt3608 charging to charge the battery direclty from usb_5v3) Then some linear regulators for 3.3 and 5v4) And again a mt3608 booster for 12V outI may utilize same booster circuit for charging the battery and 12V but then I have to change the jumpers and all, which I don't want.5) Can you suggest me a PCB manufacturer.See my schematics:

author: Kean
author_rank: Unknown
timestamp: August 19, 2024, 01:39:07 pm
content: Not sure what output currents you are hoping for, but SW2 might be under a bit of stress. Don't use some tiny SMD switch.The output capacitors on the AMS1117 are a bit small - 1uF is the absolute minimum, you probably want more. Depending on PCB layout you may also want some input capacitors on them if they are any distance from the battery.Are you planning to use protected batteries? I'm guessing the battery holders are for 18650's. I'd suggest incorporating a protection circuit if you might use unprotected cells, e.g. something like S-82C2A.How does the 1S mode selection jumper work? It just changes the charge IC output. Do you need to insert a dummy battery? I'd suggest leaving that 1S option out.I'm assuming this is just for hobby use, so you aren't concerned about EMC?Unless you need the PCB to be tiny, allow for more capacitors on each power rail. Small SMD caps are cheap, but low in value when under bias. You can always leave them off during assembly, but it is a pain to add them if there is no footprint.There might be other options local in India, but I'd suggest JLCPCB or PCBway.

author: Sagar
author_rank: Contributor
timestamp: August 24, 2024, 07:04:43 am
content: Thankyou for the review, I will take your feedback positively and changed the design. JLCPCB is quoting me low prices for the same PCB so I will go with that option. Might be a good decision for me.
Question about isolated ground below switching power supply in nRF7002 layout. - Page 1
Forum section: electronics / general

author: i509VCB
author_rank: Contributor
timestamp: August 16, 2024, 01:46:59 am
content: Hi, I am working on a PCB which contains an nRF7002. Some here would say "use a module instead": these are just to play around with.Nordic'sdatasheet(product specification) advises to put a cut in the ground plane under the switching element and related:Quote from: The datasheetAn image of layer 2:Is this advisable to copy? My intuition would say the cut in the ground plane makes an antenna. Therefore I should use a solid a ground pour. I could see the specific routing to the exposed pad on layer 2 "channeling" the return path but I am skeptical of this.

author: RoGeorge
author_rank: Super Contributor
timestamp: August 16, 2024, 09:40:09 am
content: Quote from: i509VCB on August 16, 2024, 01:46:59 amThat is the reference design from the nRF datasheet, so yes, copy all layers as verbatim as possible. There are more factors at play. That design is coming from a company that sell billions of RF chips since many generation of nRF devices. I expect their PCB design was already optimized for best performance and least EMI.I'm not sure I understood your argument for not following the reference design, but you can try 2 small batches, one with the cut and the other with solid layer, and compare their EMI performance.My bet is the reference design will work much better as it is, than without that cutout.In general, the energy is in the space between the going and the return wire, never in the wire (or the copper plane itself), so the nearby layers and the vias between layers matters the most. (I'm talking in the spirit of this video, it's a long one but it worth a watch:https://www.eevblog.com/forum/chat/fun-for-nerds/msg5583117/#msg5583117If Rick Hartley's guidelines seem strange, see the book "Fast Circuit Boards" by Ralph Morrison, where it is explained the physics behind those PCB decisions.

author: Sagar
author_rank: Contributor
timestamp: August 19, 2024, 12:29:53 pm
content: usually I have seen this type of thing with crystal oscillators and ceramic rasonators. But I think you can follow the datasheet, the cut will not make a big difference. How many layer stack-up you are using for the PCB, and how you are planning to get hands on actual PCB.

author: i509VCB
author_rank: Contributor
timestamp: August 20, 2024, 12:04:59 am
content: Quote from: Sagar on August 19, 2024, 12:29:53 pm4 layers (Nordic's reference layout is also 4 layers). The only difference to the is going to be I have no access to microvias.
Schematics and PCB review for TP5100 standard battery charger - Page 1
Forum section: electronics / general

author: Sagar
author_rank: Contributor
timestamp: August 27, 2024, 08:08:36 am
content: A basic charger IC, I want to use it in my portable power supply. TP5100 is unbalance 2s charger, is any way to make/ convert into balance charger. I made the schematics and PCB which I can use to charge, any design considerations please let me know.

author: squadchannel
author_rank: Frequent Contributor
timestamp: August 27, 2024, 08:40:07 am
content: See an example layout of a similar charger IC. TI's BQ25306:The placement of the components is too messy.The path to the inductor is too long.Since it is switching, always be aware of the shortest possible length.

author: PlainName
author_rank: Super Contributor
timestamp: August 29, 2024, 03:37:42 pm
content: QuoteWhy do you box everything into tiny sections which take significant effort to decode? Where does VBat come from, for instance? Literally, you could draw a straight connection from Vin to the chip, and it would be immediately obvious that the thing on the left is connected to the thing on the right, and isonlyconnected thus. No longer would you need to microscopically examine every label just to see if Vin happens to go somewhere else as well. (And it just so happens that now I noticed there are two Vin pins on the chip. See how easy it is to miss important stuff when you connect via labels?)You can still have your boxes to say what each bit does ("This is the chip") but what the circuit actually does, the function of it, will be much more apparent and easier to read.Now, you may say that the chip symbol doesn't really lend itself to that (it does in this case, but lets assume Vbat is on the left). That's because the symbol is showing the physical pin layout rather than the logical function. Inputs on the left, outputs on the right, group together related pins, etc.
PCB design Review of Portable power supply unit - Page 1
Forum section: electronics / general

author: Sagar
author_rank: Contributor
timestamp: August 19, 2024, 12:41:57 pm
content: I have designed this power supply unit to get 3.3, 5, 8 and 12V. So that it acts like a secondry supply to test and power small projects and mircocontroller.1) I used TP5100 as charging in 2S mode2) 5v boost up mt3608 charging to charge the battery direclty from usb_5v3) Then some linear regulators for 3.3 and 5v4) And again a mt3608 booster for 12V outI may utilize same booster circuit for charging the battery and 12V but then I have to change the jumpers and all, which I don't want. I have posted the schematics in a another post similar to this one.

author: Doctorandus_P
author_rank: Super Contributor
timestamp: August 19, 2024, 04:44:18 pm
content: PCB layout is quite bad.First rule in any dual layer PCB these days is to have a proper GND plane.You do not have a GND plane at all. There is a lot of copper, but it is cut willy nilly into little chunks.I also see something resembling an inductor footprint.Looking at your other thread:https://www.eevblog.com/forum/eda/schematic-review-portable-power-supply/I see there are one or two SMPS circuits on this PCB.SMPS circuits need a lot of special attention to PCB layout. A PCB also can not be properly reviewed without the schematic.
Useful angles for rotation and slopes - Page 1
Forum section: electronics / general

author: Nominal Animal
author_rank: Super Contributor
timestamp: August 14, 2024, 01:20:55 am
content: I've noticed that in my hobby designs, I can often get a nicer PCB layout if I rotate components. However, aligning traces can then be annoying, especially because I like to use simple rectangular grids as guides for placing traces. Picking rotation angles that match small integer ratio slopes makes it easy to use such a grid. Since I don't like to memorize things, I created an infographic, a printable poster:It's an SVG file, so it scales perfectly to any size. Feel free to use any way you like. The dark line is the exact slope, and the lighter line underneath is at the exact angle, so their convergence and divergence shows how much error there is between the slope and the angle. Only the 45° angle is exact, all other angles are approximations (rounded to either the closest full degrees, or the closest tenth of a degree).If you don't like the colors (grays), savethe SVG file, and edit it in e.g.Inkscape, or any text editor: the colors are in hexadecimal,#RRGGBB, with00=0% andFF=100%. Opacity0.0is transparent, and1.0fully opaque.