hybridfree/eevblog-posts huggingface dataset:
PCB Motherboard - Glue - Page 1
Forum section: electronics / beginners

author: 2X
author_rank: Frequent Contributor
timestamp: June 02, 2020, 07:23:57 pm
content: Hello,does anyone knows which is the name (or a link to buy) of the red glue at the yellow circles on the image? This PCB is a motherboard.

author: flolic
author_rank: Frequent Contributor
timestamp: June 02, 2020, 08:44:28 pm
content: I am using NE8800T Seal-glo red epoxy from Fuji chemicals. I bought it on ebay so can not guarantee it is genuine (probably is), but it works great.It is very strong and hard epoxy when set.

author: Gyro
author_rank: Super Contributor
timestamp: June 02, 2020, 08:49:13 pm
content: It looks like the same stuff as they use for gluing down SMD parts when they're going to be wave soldered, if so, it has decent (short term) temperature resistance.

author: 2X
author_rank: Frequent Contributor
timestamp: June 03, 2020, 06:03:46 am
content: Quote from: Gyro on June 02, 2020, 08:49:13 pmYes it seems like glue for SMD components. Which is the neme (brand) of that glue?

author: Psi
author_rank: Super Contributor
timestamp: June 03, 2020, 06:19:28 am
content: Often used to hold parts on the PCB if it needs to go through re-flow oven upside down and the part is too heavy to stay on board from surface tension alone.Also used for wave soldering SMT, but that isn't so common any more.

author: jpanhalt
author_rank: Super Contributor
timestamp: June 03, 2020, 09:17:34 am
content: Quote from: 2X on June 03, 2020, 06:03:46 amLoctite (Henkel) makes some. For home use, I just use medium cyanoacrylic glue (CA, "superglue"). The latter is not usually colored. Loctite thread locker adhesives historically are colored red, blue, and green depending on their properties. I believe Loctite's PCB adhesive is red or blue. At least, that is the color I have seen.The circled red blob on the far right does not look like one of those adhesives to me, though.

author: Sceptre
author_rank: Regular Contributor
timestamp: June 03, 2020, 04:17:19 pm
content: Loctite Chipbonder 3621:https://www.henkel-adhesives.com/es/en/product/electrically-non-conductive-adhesives/loctite_3621.htmlThere's also 328, but that's orange:https://www.hisco.com/Product/1099563-34899

author: 2X
author_rank: Frequent Contributor
timestamp: June 04, 2020, 05:40:42 pm
content: Also I found the below glue for SMD componentsPart No.:SMA10SLhttps://uk.farnell.com/electrolube/sma10sl/adhesive-syringe-10ml-sma/dp/106610
PCB mount barrel plug - Page 1
Forum section: electronics / beginners

author: mys_721tx
author_rank: Contributor
timestamp: October 25, 2020, 08:47:20 pm
content: Hello all,I am designing a PCB for Phil Salas' (AD5X) Yaesu FT-817 Input Voltage Conditioner (http://www.ad5x.com/images/Articles/Condx817RevA.pdf). The original design uses an EIAJ-02/Philmore 240 pigtail to connect to the radio.All EIAJ-02 pigtails I can find on DigiKey use 24AWG. The resistance of an 1-foot 24 AWG wire is about 0.026 Ohm, which is comparable to a 2 oz/ft^2, 2.87mm PCB trace of the same length. I managed to find Tensility 50-00621 on DigiKey (https://www.digikey.com/en/products/detail/tensility-international-corp/50-00621/10261137). The solder ear should allow me to solder it to a PCB.I am not overly worried about the mechanical stress on the barrel jack since the board would be fastened to the back of the radio by the ground screw. I will put a PCB mounting staple for the Anderson PowerPole connectors to relieve the stress there.Is using a PCB-mount barrel plug and eliminate the wires a good idea? Are there anything I am missing?

author: MarkF
author_rank: Super Contributor
timestamp: October 25, 2020, 09:46:58 pm
content: Why are you not using the proper PC mount power jack and matching plug?https://www.mouser.com/ProductDetail/CUI-Devices/PJ-037A?qs=WyjlAZoYn53bdNRXfildEA%3D%3Dhttps://www.mouser.com/ProductDetail/CUI-Devices/PP3-002A?qs=WyjlAZoYn51xCL5UiDz5Og%3D%3DAnswered my own question. Didn't read the whole PDF document.

author: mys_721tx
author_rank: Contributor
timestamp: October 25, 2020, 09:56:45 pm
content: I am trying to make a semi-permanent adapter from the barrel jack on the back of the radio to Powerpole and having a PCB mount jack won't really help.As for Powerpole, it is the standard 12VDC connector for amateur radio operation under RACES and ARES. Having it will improve the interoperability with other hams.

author: MarkF
author_rank: Super Contributor
timestamp: October 25, 2020, 10:04:18 pm
content: Could you remove the back of the plug?And then, drill and tap a 6mm hole in the case to screw the plug into.In the PDF, it looks like they epoxied the jack into their case.....

author: mys_721tx
author_rank: Contributor
timestamp: October 26, 2020, 12:53:10 am
content: Hi Mark, there seems to be some misunderstanding. I am trying to implement the design on a PCB as a practice of my PCB design skill. Therefore it would not be exactly the same as the one shown in the PDF. One of my objectives is to reduce the number of PCB to wire connections, hence my focus on the PCB mount plug.Regarding the CUI plug, it is a 2.1mm ID plug and is incompatible with the 1.7mm ID jack on the radio. Tensility 50-00621 already have two soldering ears exposed and making the PCB footprint in KiCAD does not appear to be terribly difficult.
PCB order - company says my board has a short? - Page 1
Forum section: electronics / beginners

author: somuchtyler
author_rank: Contributor
timestamp: April 07, 2017, 04:11:05 pm
content: Hey guys, just wondering what might be the matter. I made a PCB in CircuitMaker and the company says my board has a short.."Hi.As the below,your PCB has a short-line.Because each layers has silk screen,it cause the short problem. So please you check and fix."<- first attachment<- second attachment<- third attachmentWhat exactly are they saying? I am guessing the silk screen will cause a short between the routing?

author: dimkasta
author_rank: Regular Contributor
timestamp: April 07, 2017, 04:19:06 pm
content: It seems that the rectangle around the parts that should only appear on the silk screen layer, appears on copper layers as well

author: whollender
author_rank: Regular Contributor
timestamp: April 07, 2017, 04:19:27 pm
content: They're saying that the gerber files for the copper layers appear to have the silkscreen shapes included.This doesn't mean that the silkscreen itself will short anything out, it just means that the settings you used to generate the gerbers accidentally included the silkscreen drawings in the copper layer outputs.I'm not familiar with CircuitMaker, but, in most applications, there are a bunch of settings that control how the gerbers are exported. Usually you can control which application layers (annotations, routes, pads, etc) are included in each gerber file output.

author: somuchtyler
author_rank: Contributor
timestamp: April 07, 2017, 04:21:40 pm
content: Quote from: whollender on April 07, 2017, 04:19:27 pmI just realized that's exactly what they are saying, thank you!!

author: TiN
author_rank: Super Contributor
timestamp: April 07, 2017, 04:27:32 pm
content: Think of making PCB like printing on paper.But instead of ink dots on paper , you have copper metal. So whatever you print on each layer - will be metal on same sheet.One gerber layer - one "sheet of paper" which makes your PCB.So on metal layers you must have only stuff need to be in copper. Silkscreens, assembly layers, drill holes - all go "special" non-metal sheets.If you put everything in one drawing and print it - you will get everything in copperAnd on your board it means everything become shorted in nice artistic blob, hence that's what fab told you.
PCB Power Supply question - Page 1
Forum section: electronics / beginners

author: redgear
author_rank: Frequent Contributor
timestamp: July 31, 2020, 10:11:19 am
content: Will theIRM-10-5be a good power supply to be used on my PCB to power the following:1) Microcontroller(probably ATmega808/PIC16F1512/ATtiny817)2) LED 7-segment display3) Buzzer4) Relay(200mA)5) Capacitive touch controller - MTCH105/CAP1206 (Will drop this if I choose either the PIC or ATtiny as they come with PTC)6) NA555 timer7) 6 LEDsDo I need to add some filter caps or something on the output/input of this power supply? Is there something else that I should be careful about?Thanks

author: dmills
author_rank: Super Contributor
timestamp: July 31, 2020, 10:26:37 am
content: Should be fine, just be careful to get the footprint right (I somehow managed to get a footprint for the 30W version back to front) and make sure you meet creepage and clearance on the mains voltage tracking.

author: redgear
author_rank: Frequent Contributor
timestamp: July 31, 2020, 10:36:51 am
content: Quote from: dmills on July 31, 2020, 10:26:37 amThank you!QuoteHow do I check this?

author: redgear
author_rank: Frequent Contributor
timestamp: August 01, 2020, 05:06:07 am
content: I did some read up on the power supply, there are few threads here that complain about the noise generated by the powersupply, would it be a problem in my application? If yes, can I add some caps to smoothen it?

author: redgear
author_rank: Frequent Contributor
timestamp: August 03, 2020, 01:19:56 pm
content: Can someone help me choose betweenRecom RAC10-K/277andIRM-10-5? Which would be better in terms of reliability? Do I need to have bypass capacitors on input and output or can I directly connect it to the load(mcu+a relay+7seg)?Thanks
PCB prototype production company - Page 1
Forum section: electronics / beginners

author: VoidsWarranties
author_rank: Contributor
timestamp: November 24, 2016, 02:58:31 pm
content: I am looking for a good and cheap company that I can get pcbs from. I made them with fritzing and they do have their own production service but it it 25$ a board. Fritzing does let you export itIt is 20mm by 170mmDouble sidedOnly through hole no smdSent from my iPhone using Tapatalk

author: ataradov
author_rank: Super Contributor
timestamp: November 24, 2016, 06:07:06 pm
content: Export to Gerber and go to OSHPark or PCBWay.

author: Zero999
author_rank: Super Contributor
timestamp: November 24, 2016, 09:10:20 pm
content: Etchable PDF & SGV? Those formats don't sound suitable for PCBs because it won't be obvious which layer is which.

author: Blastcap
author_rank: Regular Contributor
timestamp: November 25, 2016, 08:55:31 am
content: Quote from: Hero999 on November 24, 2016, 09:10:20 pmBut useful for those who want to etch boards themself.

author: daveshah
author_rank: Unknown
timestamp: November 25, 2016, 04:37:34 pm
content: Elecrow get a recommendation from me, would be $28.50+shipping total for 10 boards of that size and they should take the exported Gerber files.

author: CraigHB
author_rank: Regular Contributor
timestamp: November 25, 2016, 05:36:19 pm
content: I have yet to find anyone cheaper than Osh Park for one off PCB fabrication. Though you can do better when numbers are higher, the usual supsects like ITead and Seeed have very good prices with a minimum quantity of ten. I've used Smart Prototyping before and they have very good prices similarly. Typically for a hobbyist you would not have need for more than one or two copies so Osh Park is going to be the cheapest option. If you're in the US the service is about the fastest you'll find. I have had boards turn around as fast as a week with them, but two weeks is more typical.The industry standard is Gerber and Excellon plot files. If you're using software that is not able to produce those, you'll need to migrate to something that can. There was (is?) a trend for prototyping services to require use of their own in-house CAD software in an effort to lock you into their service. Typically their CAD programs use a proprietary file format and are not able to produce Gerbers. The software can be pretty good, Express PCB is one, but it's not a good thing to pigeon hole your designs like that. It's going to give you trouble at some point.
PCB recreation help <3 - Page 1
Forum section: electronics / beginners

author: Yunadex
author_rank: Contributor
timestamp: July 20, 2025, 07:16:41 pm
content: i was looking to recreate a little charge splitter i saw for my own use i have a picture of it but i don't know what all the components are and what is essential for it to function,plugged in devices will only draw 100mA for charging small 180mAh batteries, i made one previously but i think it is way overkill as it uses a barrel jack to supply a max of i think it was 1.5A per port which is just WAY overkillwanted to make a cheaper solution as this board will really only be used for these small devicesthanks in advance! <3

author: Doctorandus_P
author_rank: Super Contributor
timestamp: July 21, 2025, 12:53:17 am
content: You can also start with for example this project:https://github.com/MILOUDIAS/SimpleUSBCChargerIt has a complete KiCad (Free & Open Source Software) project, complete with schematic and PCB.It is a very simple project though. Just a very small PCB with some connectors and resistors. But because the project is complete, you can easily extend it in any way you like.You can also use:https://devbisme.github.io/RepoRecon/It's a relatively simple script that searches gitlab for (among other things) KiCad projects on github.with "charger usb" it finds 20 different KiCad projects.
PCB Review: 2 layer ESP8266 Huzzah breakout board with SPDT switches. - Page 1
Forum section: electronics / beginners

author: tylerssims
author_rank: Contributor
timestamp: December 07, 2022, 08:00:14 am
content: EDIT: Current layout and schematichttps://imgur.com/a/JtZtVVbHi all,I'm looking for feedback on my board and design in general. It is the controller board for another PCB with 14-segment displays.It is a breakout board for an Adafruit ESP8266 Huzzah module. My board takes the Huzzah module, breaks the pins out to headers, adds an LDO regulator to the VBUS, and adds 4 push button switches to enable various pins.I have also included two potentiometers configured as variable resistors. One is a variable pull up resistor, and the other is a variable pull down. They are each connected to an empty pin header and have no other input. I included them in case I need more resistance for my I2C bus or if my internal pull up/downs for certain pins are insufficient. I know it's not very practical but I thought it would make for quick troubleshooting and would be fun to build. Please let me know what you think.https://imgur.com/a/kk4WuLrThe traces are mostly 0.5mm with 0.5mm vias.Thanks!

author: juma98
author_rank: Contributor
timestamp: December 09, 2022, 03:51:53 pm
content: TP5 is not connected.

author: mariush
author_rank: Super Contributor
timestamp: December 09, 2022, 05:54:39 pm
content: You have plenty of room to put the RESET and WAKEUP buttons to the left of the other buttons. Move the IC1 more to the left, trace to SW3 can be routed above the bootstrap button and then between the other button...You're using a 1117 regulator, probably the kind that's stable with ceramic capacitors on the output but who knows if some person copies your design and doesn't know 1117 aren't all the same... maybe consider using something else, personally don't like to use them.Nothing really wrong with it, but that trace going from RV2 to the bottom trace at that angle bothers me. Maybe it could go directly down to that 3.3v pad instead of cutting over the silkscreen or whatever?

author: bidrohini
author_rank: Regular Contributor
timestamp: December 11, 2022, 02:11:38 pm
content: You can post your design here:https://www.pcbway.com/project/questionpublishI think you'll get many more insightful reviews from there.
PCB Split Power Planes - Page 1
Forum section: electronics / beginners

author: Melon
author_rank: Newbie
timestamp: November 07, 2019, 12:04:39 pm
content: I have a good understanding about ground planes and current return paths, how a slotted ground plane can cause return currents to divert from the optimal path underneath the signal (for high frequencies) and cause a lot of crosstalk and EMI problems. However just now I read about split power planes and I started looking for advice. Everywhere I looked it is said that it is not a good idea to route signals over a split power plane, but I haven't found a good explanation for this. Why is it bad to cross a split power plane? The return current goes through ground, so the path is not disturbed by the slots in other planes, as I have represented in the drawing I attached. Is there a different reason I'm not looking into (such as t-line impedance mismatch)? I'd like a clarification on this topic. Thanks.

author: chagli
author_rank: Contributor
timestamp: November 09, 2019, 10:14:35 pm
content: Hi,I am quite new in the EMC field.I think the return path is fine for the desired signal in your case.But the return path for any RF noise signal superimposed on this signal is bad because it is the same. Let me explain.This RF noise signal should use the plane just beneath, irrespective if it is ground of power: at RF, the noise can go through decoupling capacitors and change plane easily. In your stackup, the RF noise should return on layer 2 which is split and thus goes through layer 3 which is further away from layer 1 meaning higher inductance, radiated field etc.The solution here would be to route on layer 4 because the plane just above is not split.You can see the RF current path in the figure below.There's also the skin effect which prevents the RF current to cross a plane. The current then has to follow the outer surfaces...I recommend you "split ground/power planes" section from the great book of Henry W. Ott : "Electromagnetic Compatibility Engineering".
PCB Test Point and Signal Integrity - Page 1
Forum section: electronics / beginners

author: vvanders
author_rank: Regular Contributor
timestamp: December 05, 2012, 05:20:54 am
content: I'm working on building out a 2 layer PCB that's got some analog and digital pieces, I want to add test points so that I can look at them with a scope to make sure they are working as expected. However I don't want to degrade the signals significantly due to the test points that I add.On my pcb I've got three areas I want to build in test points:Analog front end feeding a 250ksps 16 bit differential ADC, highest bandwidth input signal I should see here is around 50Khz.20Mhz Serial bus which should have a very short run to a CPLD.8Mhz SPI bus from CPLD to uC.I've seen test loops, is there any signal integrity reason to use these instead of .1 headers at the speeds I'll be looking at or is it just for ease of probe attachment?Most of what I've read seems to point to just putting a via in the signal path and soldering in the test point, is this generally the best way or are there other better layout techniques?As for the board design I plan to have separate analog and digital ground plans in addition to separate voltage regs. From what I've read that should cover me for the speeds I'm planning on using.

author: AndyC_772
author_rank: Super Contributor
timestamp: December 05, 2012, 07:46:01 am
content: At those frequencies, adding a test point won't make the slightest difference. You'll be fine.You say it's a 2 layer board; is one of those layers a ground plane? If not, you might like to consider making it a 4 layer board instead, with GND on layer 2 and a power plane on 3. That will make a much bigger difference to your board's signal integrity than any test point.

author: SeanB
author_rank: Super Contributor
timestamp: December 05, 2012, 03:41:49 pm
content: If you are putting in test points use a 2 pin header, and make a local ground connection for the scope, to keep ground impedance down. You can also use a 2 socket header attached to a sacrificed cheap 10X probe to make a simple test jig.

author: vvanders
author_rank: Regular Contributor
timestamp: December 06, 2012, 03:21:59 am
content: Thanks for all the information, good to hear that it's not going to be an issue.I plan to have solid ground planes around all of the high speed signal paths and to keep crossovers into the ground plane as few as possible. I'd like to go 4 layer but even Eagle is $170 for the hobby license and the cost of boards is high for just a side project like mine.
PCB to scheme. - Page 1
Forum section: electronics / beginners

author: deandadnaed
author_rank: Contributor
timestamp: April 06, 2019, 09:55:05 pm
content: Hi!I’m trying to understand and simulate a Power Supply. Wiring is very clear for me. But the PCB’s aren’t.Is there a way to reverse engineer a PCB and obtain its diagram/scheme?The first piece I want to describe is this:Enviado desde mi iPhone utilizando Tapatalk

author: viperidae
author_rank: Frequent Contributor
timestamp: April 06, 2019, 10:07:11 pm
content: Take a picture of the track side, print it out then draw the components on it.From there it's much easier to start drawing out the schematic

author: deandadnaed
author_rank: Contributor
timestamp: April 06, 2019, 10:30:19 pm
content: Quote from: viperidae on April 06, 2019, 10:07:11 pmThank you very much!Enviado desde mi iPhone utilizando Tapatalk

author: alex.martinez
author_rank: Contributor
timestamp: April 06, 2019, 11:50:21 pm
content: Quote from: deandadnaed on April 06, 2019, 09:55:05 pmAt least it is a one-sided board. The problem with power supplies and several-model electronics is that they make a master PCB with all the features, then fabricate that one, and for lower-tier models they remove some of the sub-systems.The advice above is pretty solid, but take into account not all component hoels are populated... and probably there is a good portion of traces shorted to ground. I would start from there, use te continuity meter and start checking which ones are shorted, where do the "0 ohm" go and so on.

author: jerryk
author_rank: Regular Contributor
timestamp: April 07, 2019, 12:34:29 am
content: Here are some different views of your board that might be helpful.Jerry

author: soldar
author_rank: Super Contributor
timestamp: April 07, 2019, 09:09:36 am
content: Here is a composite view of a power supply I had to repair. This is a reduced size, the original is larger. It allowed me to reverse engineer the schematic and then repair it.I flipped over the photo of the traces and superimposed a transparency of the components and annotated by hand in two different colors for traces and for components.A good way to kill some time and forget your troubles. Very therapeutic. Especially recommended after an argument with the wife. (Or, better still, before even thinking of arguing.)

author: soldar
author_rank: Super Contributor
timestamp: April 07, 2019, 09:15:57 am
content: A SMPS with adouble sided PCB.Correction: After looking at it again I think it is single sided but I colored the GND green and the rest blue. They do not cross so it looks like single side. There are wire bridges in red.
PCB top/bottom image alignment tool - Page 1
Forum section: electronics / beginners

author: Prehistoricman
author_rank: Regular Contributor
timestamp: August 15, 2021, 05:59:47 pm
content: I'm looking for a tool that would allow me to transform images of a PCB taken at odd angles, maybe different distances, and align them such that all the vias and such line up.Normally you'd just take a top and bottom image from the same distance and angle and then do minor alignment in a basic image editor.My situation is that I have images of PCBs that I don't have, and I can't get more images of them. However I would like to trace the connections easily which requires alignment.I've tried a tool called Hugin but it's really not made for this. It has a "control point" interface where you specify points on the images that are the same point in real space. However, Hugin requires a lot of these points and can simply reject them.Otherwise I've just been using Paint.NET but it's all manual and doesn't offer very advanced rotation/translation/view manipulation.

author: Renate
author_rank: Super Contributor
timestamp: August 15, 2021, 11:08:00 pm
content: Gnu Gimp can remove perspective/rotation/scale from an image.Tools > Transform > PerspectiveMaybe set a reference layer up with a rectangle?I dunno, the learning curve is steep with Gimp if you are used to MS Paint.

author: Prehistoricman
author_rank: Regular Contributor
timestamp: August 15, 2021, 11:41:01 pm
content: Ok thanks, I'll try it.I think the learning curve is steep regardless. I've seen GIMP before and was immediately lost. That's why I've always used Paint.NET (not MS Paint btw).
PCB Trace Best Practices? - Page 1
Forum section: electronics / beginners

author: Holmes34
author_rank: Contributor
timestamp: October 17, 2016, 01:02:25 pm
content: Hey all!Recently I've been getting interested into making my own stand-alone projects based on ATtiny microcontrollers, and in the process of climbing the steep learning curve of Eagle, I've realised that I should probably get some advice on the "best practice" for routing traces and some other basic PCB design questions.The current board I'm working on is for controlling 2 small servomotors and a cheap laser diode in constant current. I haven't finished adding all of the components and elements I want/need, but I decided I should get help earlier rather than later! Attached is the current state of the board in Eagle.Is it appropriate to route the traces in-between the pins of the MC (the 8 pins on the right)? Is it appropriate to route a trace through a pad, or should I aim to only connect pads by "branching" off a main "rail"? Is it ok to route traces under a component (e.g. under the MC body)?Disclaimer: Many things in this post might be laughably silly! I am not liable if you laugh yourself to death!

author: Aeternam
author_rank: Unknown
timestamp: October 17, 2016, 03:02:57 pm
content: Hey Holmes,You might want to take a look at Dave's PCB design tutorial, there's a lot of good info there:https://www.eevblog.com/forum/eda/pcb-design-tutorial-by-david-l-jones/

author: lem_ix
author_rank: Regular Contributor
timestamp: October 17, 2016, 03:03:52 pm
content: If you're going to send the board to a fab, they have a set of design rules you need to follow like 10/10, meaning 10 mils min trace width, 10 mils clearance minimum. Generally it's ok to route between the pads if you can follow the clearance rule for your trace size. It's also perfectly fine to run a trace under a component, unless there's a specific reason not to, like noise coupling of some sort. For DIY PCBs I guess it depends on your skill, it's fine to do if you can make a pcb with finer traces but most people use wider ones for that. Another point to maybe consider is whether you'll be soldering around that point. Think about when you assemble the board, will it make soldering more difficult etc.

author: alexanderbrevig
author_rank: Frequent Contributor
timestamp: October 17, 2016, 03:09:15 pm
content: You probably want some decoupling caps

author: Holmes34
author_rank: Contributor
timestamp: October 17, 2016, 03:26:56 pm
content: Quote from: alexanderbrevig on October 17, 2016, 03:09:15 pmDefinitely!
PCB trace inductance and y capacitors - Page 1
Forum section: electronics / beginners

author: Tor
author_rank: Newbie
timestamp: May 06, 2016, 07:32:38 am
content: Hi semi? beginner here with 1 year as hardware designer.I work with high power(3,5-10.5kW) hard switched PFCs which generates allot of noise and during layout there is quite allot of different considerations to take into account. This leads me to my question placement of y capacitors and the trace inductance i assume that if i reduce the inductance in the trace i can place the y capacitors in other locations than the optimal since it then (trace+capacitor) would have the same SRF.These capacitors are intended for this noise return loop : Noise source->metallic housing -> y capacitors-> high power tracks(return to source)If you double the track width do you reduce the inductance of that track by 50%? This is what basic theory tells me (assuming two separate 1 turn inductors with zero distance between them for the tracks) however when i googled pcb track inductance the full return path seems to play a role and the above basics dont seem to be to correct and you get formulas where track thickness and width do not matter to much for the inductance.Anyone know if i can calculate the inductance as i think with two separate wires for this case or what basic magnetic theory i have forgotten?

author: Kleinstein
author_rank: Super Contributor
timestamp: May 06, 2016, 08:43:04 am
content: It is very hard, to impossible to assign an meaningful inductance to a straight conductor. Inductance is defined in a closed current loop, and a major factor there is the area of the loop, not the length / width of individual traces.So the trouble with the line width is that you can calculate the local inductance (local field close to conductor) if it is far away from the rest of the loop, but this implies that the local part is only a very small part of the hole system.The substitution with two wires ignores the interaction between there field or there mutal inductance.

author: Alex Trofimov
author_rank: Contributor
timestamp: May 06, 2016, 11:07:30 am
content: Hi)Try Saturn PCB Toolkit to calculate track's inductance.If you make the loop wider, then EMI would be worse, while parameters of the filters are still the same.Sorry, i'm not into PSU design and barely familiar with EMC (no one cares about EMC in Russia, let me tell you)), it's just basic considerations.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: May 06, 2016, 02:56:23 pm
content: Inductance does vary with trace width, but that's only half the equation. The other half is determined by the speed of light, which does not vary.I never found SRF of a capacitor to be a useful property, anyway.If you need filtering at such frequencies where stray inductance matters, you should probably use a self enclosed power line entry / filter module instead.Tim
PCB track/pad size calculation with mosfet - Page 1
Forum section: electronics / beginners

author: Vindhyachal.takniki
author_rank: Frequent Contributor
timestamp: September 01, 2016, 11:08:30 am
content: 1. I am working on application in which there are CHG & DSG mosfet in circuit. I can connect any no of mosfet for CHG or dsg.CHG & DSG fets are in series so equal current flows through them.2. In my circuit I have to design it for 10A application. VGs for both CHG & DSG fets are guranted to be 10V always. selected FDS6690A mosfet for this. Will use 3 parallel mosfets for CHG & 3 for DSG.3. This webiste:http://www.4pcb.com/trace-width-calculator.htmlgives idea for PCB trace width for current specified.4. Now looking at datasheet of mosfet, how much trace/pad length I should use for 10A so that temperature rise should not be more than 20C & ambient temp is 25C?

author: danadak
author_rank: Super Contributor
timestamp: September 01, 2016, 02:43:26 pm
content: If you go to TI's web site they have a tool, Webench, that includesa thermal utility to aid in design.Regards, Dana.

author: Vindhyachal.takniki
author_rank: Frequent Contributor
timestamp: September 10, 2016, 08:34:20 am
content: https://www.saturnpcb.com/pcb_toolkit.htmunder "Thermal Tab". gives option on how much heat sink temperature will go for mosfet IC.Is there any software which can explain how much track width should be for any mosfet around its drain & source for particular temperature rise.E.ghttp://www.4pcb.com/trace-width-calculator.html, mention on how much allowabke temperature rise, current , what should be the track size.
Pcb transformer - Page 1
Forum section: electronics / beginners

author: Trogladite
author_rank: Newbie
timestamp: November 21, 2021, 07:32:27 pm
content: Help please .. I have a 170 mig welder and I have located the problem being a 6 pin mounted pcb 220v to 24v transformer. And I caant find the same one anywhere. So I unwrapped the secondary coil and the primary is burnt together and can't remove unless pull all out. I can't there for determine turns needed to get the 240v.and how would I gauge the wire ? Would a similar pub work and what amp or watts would I need ?Regards in anticipation PaulAny help would be greatly appreciated

author: Gregg
author_rank: Super Contributor
timestamp: November 21, 2021, 07:47:29 pm
content: To see if the transformer is the only problem, you could extend wires from the pcb out to an external transformer of similar size or perhaps a little bigger capacity. A couple of fuses in the lines may save a fire if something else caused the original transformer to fry. Use wire of suitable size with insulation voltage rating for the application.Be aware that transformer primaries can overheat because of too high a load or short on the secondary.

author: tautech
author_rank: Super Contributor
timestamp: November 21, 2021, 08:03:02 pm
content: RS has pages of PCB mount transformers.Consider using a 2x 12V model with windings in series.https://nz.rs-online.com/web/c/power-supplies-transformers/transformers/pcb-transformers/?searchTerm=PCB%20transformer

author: Trogladite
author_rank: Newbie
timestamp: November 22, 2021, 07:54:09 am
content: Thanks for info Greg much appreciated. Would you happen to know if standard pcb are 12v as the wire feed motor says 24v on it

author: mikerj
author_rank: Super Contributor
timestamp: November 22, 2021, 11:33:26 am
content: Post a photo of the original transformer, it's ratings should be printed on the outside.

author: Gregg
author_rank: Super Contributor
timestamp: November 22, 2021, 05:39:07 pm
content: Your poor burned transformer could be any voltage depending on the design of the welder. A careful examination of the board it was mounted on may provide some clues or better yet a schematic which is probably unobtanium.Post some pictures and model of the welder and someone on the forum may be able to help.If the board mounted transformer also provides power for the wire feed motor, there may be a separate winding for control voltage. It all depends on the design.The fact that you stated it had 6 pins seems to point toward a transformer with more than one secondary winding.

author: Anthony G.
author_rank: Newbie
timestamp: November 27, 2021, 04:01:05 am
content: Quote from: mikerj on November 22, 2021, 11:33:26 amA 12V motor draws twice the current that a 24-V motor uses. The wires in a 12V motor will also be twice the size compared to a 24V motor which runs more efficiently.
PCB via and track dimensions - Page 1
Forum section: electronics / beginners

author: ghazal13
author_rank: Newbie
timestamp: March 05, 2018, 09:52:48 pm
content: Hi guys,I have recently started a PCB project. I finished the circuit design in schematic but I have some problems in designing its PCB.Would you please recommend "via hole size" and "track width" in metric system for these cases: low density and high density ?I've searched the net but I couldn't find a proper answer.The producer can support these items with the given technical data:Min Hole Size 0.2mmMin Annular Ring 0.15mmI wanted to know that what is the best size for via hole and track width in order to have a durable board that can properly transmit signals.Thanks

author: Benta
author_rank: Super Contributor
timestamp: March 05, 2018, 10:05:36 pm
content: No way to give a coherent answer here. Digital circuit? Analog circuit? High power? Low power?If it's a digital/logic design, the default settings of your PCB design software are a good starting point. For analog or power, you'll need to research further.

author: invzim
author_rank: Contributor
timestamp: March 06, 2018, 10:56:47 am
content: My 'standard' for 'normal' signals are 10mil traces. For via's I use 0.6mm diameter, 0.3mm drill. I experimented with 0.3mm/0.5mm via's and seems to work OK, but not sure if it's by the book.With 10mil traces and 0.3mm drills, pretty much anyone can manufacture your boards reliably and very cheap.

author: bson
author_rank: Unknown
timestamp: March 06, 2018, 05:12:07 pm
content: 0.8/0.4mm vias and 12/12mil w/s is a fine starting point for your first board. 0.6/0.3 and 8/8 w/s is a pretty common limit for dirt cheap prototype boards, so use that if you need the space to escape some high pin count chip. Some houses will specify finer dimensions of course.1.0/0.15mm for dot matrix silkscreen text.
PCB - Page 1
Forum section: electronics / beginners

author: remon404
author_rank: Newbie
timestamp: December 13, 2013, 05:42:06 pm
content: Just now I am doing to start from here.I am Electronic Hobbyist. Recently i am getting interest about PCB. so want to know which software should i use get started?

author: AndersAnd
author_rank: Frequent Contributor
timestamp: December 13, 2013, 05:50:15 pm
content: DipTrace Litehttp://diptrace.com/buy/non-profit/Email them as described at the link above to get a free non-profit license for 500 pins and 2 signal layers.There's also a freeware version for 300 pins and 2 signal layers, but if you are not going to use it commercially you might as well email them and get the free license for 500 pins.Other popular free alternatives are Eaglehttp://www.cadsoftusa.comand KiCADhttp://www.kicad-pcb.org/display/KICAD/KiCad+EDA+Software+Suitebut I find DipTrace much easier and more intuitive to use. I hate drawing schematics in Eagle.

author: ttp
author_rank: Regular Contributor
timestamp: December 15, 2013, 06:02:31 am
content: You can also try DesignSpark PCB - free and no limits but not very popular.http://www.designspark.com/eng/page/designspark-pcb-home-page

author: hagster
author_rank: Frequent Contributor
timestamp: December 15, 2013, 09:15:34 am
content: I use Designspark its moslty really good. Also I don't need to worry about paying out for a pro version if I suddenly find my design getting more complex. As far as I can make out pretty much all the packages are good for 95‰ of people. It's only when you get into really complex and high speed boards that things like Altium come into there own.
PCBA baking requirement prior rework for BGA location - Page 1
Forum section: electronics / beginners

author: MarkPham
author_rank: Newbie
timestamp: June 14, 2024, 01:43:30 am
content: Hi experience membersI'm looking for an standard (IPC) that mentions about the baking condition for PCBA prior rework at BGA locationDo you know where it's mentioned?I chek IPC 7711/7721 and didn't see it.Please advise and share it to meThanks for your supports.
PCBs made from chicken feathers and soybeans? - Page 1
Forum section: electronics / beginners

author: ChrisW
author_rank: Contributor
timestamp: August 15, 2014, 06:04:55 pm
content: http://science.howstuffworks.com/37289-g-word-chicken-circuit-boards-video.htmI don't see how this could be remotely practical.

author: SeanB
author_rank: Super Contributor
timestamp: August 15, 2014, 06:25:18 pm
content: Well, SRBP is made from wood pulp and cow urine ( basic ingredients but normally you get the urea from a Haber process plant) and most resins start off as a big tank of yeast that ferments to make assorted alcohols which are treated and turned into aldehydes and ketones which are then used to make polyester resins. There is a plant near me, NCP alcohols, which makes these precursors and the resins. You can smell what they are making from outside.

author: PA0PBZ
author_rank: Super Contributor
timestamp: August 15, 2014, 06:35:57 pm
content: "Because if you can get air into a circuit board the electrons travel faster in the copper wires" (0:58)

author: TimNJ
author_rank: Super Contributor
timestamp: August 15, 2014, 06:41:38 pm
content: Quote from: PA0PBZ on August 15, 2014, 06:35:57 pmYeah wtf was that about. Not against the idea of some sort of bio-PCB but whaaaaat?

author: ConKbot
author_rank: Super Contributor
timestamp: August 15, 2014, 07:49:15 pm
content: More air in a PCB = lower dielectric constant, and (generally) a higher velocity factor and lower loss tangent. Will the electrons move faster? I'm not sure, dont think the drift velocity will change, but the velocity factor will be higher, which means the signal moves at 0.8 x C instead of 0.67 x CFor RF stuff this will be calculated and compensated for, so minimal effect there, however since a single wavelength is larger on the board, it would be a bit more insensitive to manufacturing tolerances?Either way, the dielectric constant being constant throughout the material, and not changing with temperature and humidity is way more important than it being as low as possible.

author: Po6ept
author_rank: Regular Contributor
timestamp: August 15, 2014, 07:56:07 pm
content: Quote from: TimNJ on August 15, 2014, 06:41:38 pmIt's the same science used in those special "Enhanced Loud Oxygen-Free Copper" audio cables. Oxygen on the outside and not in the middle!You really need to pay more attention when Marketing does those PowerPoint presentations...
PCBWAY embedding resistors and capacitors - Page 1
Forum section: electronics / beginners

author: Capernicus
author_rank: Frequent Contributor
timestamp: January 21, 2022, 04:48:02 am
content: So if you were getting a PCB made by PCBWAY, could you actually put the capacitors and resistors on the pcb design itself. (in copper.)So there is no plotting to be done.Im looking for 30 ohm resistance for the resistor, and 100 fempto farads for the capacitor. is it possible?

author: T3sl4co1l
author_rank: Super Contributor
timestamp: January 21, 2022, 05:28:19 am
content: 30 ohms is a lot to ask from copper, at normal design rules. 100fF is fine.The tempcos of both are rather extreme: copper is, what is it, a bit worse than PTAT I think? And the capacitance is whatever the laminate is, so depends on whether you're doing sandwich (traces above/below) or adjacent (traces on same layer), and obviously there's no shielding to surroundings.The other reason Cu sucks for resistance is its inductivity. Typically reactance dominates above 10-100kHz, even for structures that attempt to cancel out inductance (e.g. hairpin loops instead of spirals). So it's hopeless as a current-sense resistor (where the small resistances might prove useful) in switching circuits.Or did you mean embedded components as in carbon ink, chips embedded in the stackup, etc.? Which are also possible -- but I can't imagine a proto fab doing such esoterica..? I mean unless that's what they've said they can do, I haven't checked anything.Tim

author: Capernicus
author_rank: Frequent Contributor
timestamp: January 21, 2022, 05:34:43 am
content: I just mean copper, and preferable single sided. I'm expecting not being able to print carbon at PCBWAY.Laminating and sandwhich a top and bottom for the caps, that sounds cool. just lining them up, have to be a little careful.30ohm resistance is more for nichrome than copper. So the caps are a go, and the resistors are a nogo.Especially if you wanted to support say 300 watts, itll blow the trace easily.There might be something I can do tho, if I make it an AC system instead of a DC system, and I use caps to limit the amps instead of resistors.Thanks for the advice.

author: PKTKS
author_rank: Super Contributor
timestamp: January 21, 2022, 12:39:29 pm
content: hmmm this is that blending point where we start considering COB and not PCB (discrete) anymore..And COB.. you know.. if anything fails or deviates... it goes landfills...Paul

author: Capernicus
author_rank: Frequent Contributor
timestamp: January 21, 2022, 08:15:28 pm
content: Quote from: PKTKS on January 21, 2022, 12:39:29 pmIts a precursor to making your own asics, even tho there is plottable components small enough to work as well, but its too much work involved IMO.
PCBwing and altium outputs, which is which? - Page 1
Forum section: electronics / beginners

author: Hypernova
author_rank: Unknown
timestamp: July 18, 2010, 11:21:12 am
content: Trying to generate the necessary files to send to PCB wing and need some help on what files they want.Not using silk screen. The top and bottom stuff is obvious enough but not sure about board edge and separate drill filesThey want:Code:GerberTop Silkscreen layer:GerberTop Solder Mask layer:GerberTop Copper layer:GerberBottom Copper layer:GerberBottom Soldermask layer:GerberBottom Silkscreen layer:GerberBoard Outline:ExcellonExcellon Format Drill File ( RoundHoles ):*ExcellonExcellon Format Drill File ( SlotHoles ):ExcellonFabrication Drawing:ExcellonNonplated Drill File:GerberAperture For 274D Format:TextTool Size Report:TextReadme File(Explain special process only):What I got: (4:2 metric relative)Code:18/07/2010 09:04 p.m. 832 Main Board-BoardEdgeRout.TXT18/07/2010 09:02 p.m. 3,092 Main Board-macro.APR_LIB18/07/2010 09:02 p.m. 4,275 Main Board.apr18/07/2010 09:04 p.m. 7,468 Main Board.DRL18/07/2010 09:04 p.m. 1,552 Main Board.DRR18/07/2010 09:02 p.m. 1,033 Main Board.EXTREP18/07/2010 09:02 p.m. 300,254 Main Board.GBL18/07/2010 09:02 p.m. 22,362 Main Board.GBS18/07/2010 09:02 p.m. 112,567 Main Board.GD118/07/2010 09:02 p.m. 50,144 Main Board.GG118/07/2010 09:02 p.m. 323,710 Main Board.GTL18/07/2010 09:02 p.m. 44,901 Main Board.GTO18/07/2010 09:02 p.m. 22,569 Main Board.GTS18/07/2010 09:04 p.m. 158 Main Board.LDP18/07/2010 09:02 p.m. 2,981 Main Board.REP18/07/2010 09:02 p.m. 566 Main Board.RUL18/07/2010 09:04 p.m. 8,256 Main Board.TXT18/07/2010 09:04 p.m. 379 Status Report.Txt+two .cam files from the gerber output and the NC drill output.
PCBz Traces Q... - Page 1
Forum section: electronics / beginners

author: Mo3tasm
author_rank: Contributor
timestamp: November 30, 2013, 08:17:05 pm
content: Hello!, Can you explain why some traces are often look like this?image courtesy: ifixit.com

author: c4757p
author_rank: Super Contributor
timestamp: November 30, 2013, 08:20:16 pm
content: Length matching. The ones that would end up shorter than their neighbors are folded up to get extra length, so that there's no skew between the signals at the end.

author: Mo3tasm
author_rank: Contributor
timestamp: November 30, 2013, 08:27:44 pm
content: Quote from: c4757p on November 30, 2013, 08:20:16 pmallright Thanks, now i can look it up for more...

author: cloudscapes
author_rank: Regular Contributor
timestamp: December 01, 2013, 02:14:38 am
content: the speed of electricity (light) is still finite O0it's cool to think about that now we're able to build stuff that takes the fastest stuff in the universe into consideration!

author: peter.mitchell
author_rank: Super Contributor
timestamp: December 01, 2013, 03:05:05 am
content: Quote from: Mo3tasm on November 30, 2013, 08:17:05 pmI like you.