hybridfree/eevblog-posts huggingface dataset:
OrCAD training like Fedevel? - Page 1
Forum section: electronics / general

author: Pack34
author_rank: Frequent Contributor
timestamp: August 08, 2018, 11:12:45 pm
content: I've been incredibly efficient with Altium but with a new job comes new tools. Is there a similar suite of courses like Fedevel Academy does for Altium, but targeting OrCAD? I found it really helped me get my feet wet and run with it.

author: robertferanec
author_rank: Regular Contributor
timestamp: August 09, 2018, 02:44:53 pm
content: @Pack34 I created also OrCAD course. You can find it on FEDEVEL Academy, here:https://www.fedevel.com/academy/online-learn-orcad-and-allegro-essentials/PS: The course is for everyone starting with OrCAD and Cadence Allegro (or for everyone moving to OrCAD and Allegro). It is step-by-step course, so just follow the video and you will learn the complete board design process in OrCAD. I hope this helps.

author: Pack34
author_rank: Frequent Contributor
timestamp: August 09, 2018, 03:13:09 pm
content: Thanks! I didn't see it earlier.Fantastic videos and tutorials.

author: robertferanec
author_rank: Regular Contributor
timestamp: August 10, 2018, 05:39:01 am
content: Quote from: Pack34 on August 09, 2018, 03:13:09 pmThank you
Where to find low cost custom bezels for aluminum enclosure? - Page 1
Forum section: electronics / general

author: Martin F
author_rank: Regular Contributor
timestamp: August 18, 2018, 02:36:37 pm
content: Hi all,We’ve got an extruded aluminum enclosure with custom cut end plates. When we screw in the end plates we find that there is a small gap sometimes - and even when there isn’t, the line where the enclosure and end plate meet is not visually appealing.We’ve though about ways to “hide” this - eg rubbers, bezels or similar. Any ideas for what to use in our case? And where custom made solutions can be made at low cost?Thanks!

author: kosine
author_rank: Regular Contributor
timestamp: August 21, 2018, 06:01:59 pm
content: Something like this might work:https://uk.farnell.com/hammond/1455pbtrd/enclosure-1455-bezels-red/dp/1415136Just need to add some laser cut end panels.

author: Martin F
author_rank: Regular Contributor
timestamp: August 21, 2018, 07:29:56 pm
content: Thanks for the tip! Our entire enclosure is ~3$ so perhaps we're underestimating the cost of the bezels relatively :-) but great page!
Embedding MFG information in  - Page 1
Forum section: electronics / general

author: Pack34
author_rank: Frequent Contributor
timestamp: August 09, 2018, 03:20:20 pm
content: I'm working with OrCAD Capture CIS.In Altium I would create very well defined libraries, such as "Resistor 0402 Yageo", so-on and so-forth. Each component in that library would be linked to the DigiKey part so I would never have to manually enter in anything. All the information is there.However, so far I'm only seeing the option to link information to DigiKey through the "Part Linker" after it's been placed in the schematic.Is there a way to do this in the libraries themselves, or am I forced to using generic component libraries and then attribute them to the vendor after it's in the schematic? I would love to pick the exact part I need from the library and use that. Otherwise it opens the door to errors and inconsistencies.Is this simply the OrCAD workflow?
Package Dimensions of Components  - Page 1
Forum section: electronics / general

author: hw01.jt
author_rank: Newbie
timestamp: August 01, 2018, 09:51:30 am
content: hello everyone ,In IPC STANDARDS WHAT IS THE CONVERSION CRITERIA FOR CONVERTING COMPONENTS DIMENSION in mm to inchfor ex.when i selecting component package of 3528 mm and when i trying to get in inch then the actual problem arises ....if i convert 35 mm *28 mm into inch then i get 1.377*1.10, so is there any rounding system in dimension ? and if yes then how many decimal places ? because there are both type of packages are available in market like 1311 and 1411 .so i hope you will able to clear my doubt .

author: Siwastaja
author_rank: Super Contributor
timestamp: August 01, 2018, 09:56:09 am
content: Hard to understand what you are after.There are no special conversion factors. 1 inch = 25.4mm and that's it. Don't do unnecessary rounding. If you round, round an order of magnitude below your PCB manufacturing / placement accuracy so that it doesn't matter.3528mm or 3.528 meters is quite a heck of a component dimension! I guess you need several people to pick/place it.If you are thinking about magic number sequences in package names, they are just that, names, nothing else. You always look at the actual drawings for dimensions, from the actual manufacturer. You can't work on an assumption that a package name number sequence that resembles the dimensions would actually contain any exact or useful dimensions of the part.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: August 01, 2018, 10:54:10 am
content: Who needs inches in India?(Contracting to US?)But yes... units are just that, units, a multiplier, nothing more. 1 inch is defined as exactly 25.4mm (the US is technically metric, customary units just have a different multiplier on them because...reasons).Conversion is trivial with various tools:https://www.google.com/search?q=3528mm+in+inches&oq=3528mm+in+inchesTim

author: apurvdate
author_rank: Contributor
timestamp: August 02, 2018, 06:01:37 am
content: Quote from: Siwastaja on August 01, 2018, 09:56:09 amLOL.. i think he means if package in metric 3225 what is its equivalent in imperial.. which will be 1210its not 3528 mm.. it should be 3.5mm x 2.8mmQuote from: hw01.jt on August 01, 2018, 09:51:30 amhttp://www.resistorguide.com/resistor-sizes-and-packages/this page may help you understanding conversion.. but personally i havn't seen/used 3528 package..edit: even i missed some decimal points
PCB Image -> Voronoi gcode - Page 1
Forum section: electronics / general

author: Pugbutt
author_rank: Contributor
timestamp: April 22, 2018, 12:24:52 pm
content: Hi Everybody.I just put a new project on GitHub that may be useful. It's a JavaScript app that processes a PCB artwork, does a Voronoi tesselate, then outputs G-code for a laser etcher or the like.I'm definitely not the first to do this, but this one lets you define signal traces that are to stay skinny, plus runs in your browser without any other dependencies.https://github.com/caiannello/jsVoronoiPCBCheers,Craig

author: Pugbutt
author_rank: Contributor
timestamp: April 27, 2018, 02:30:45 am
content: One can spray paint a piece of copper-clad, blast it with a $200 laser engraver from China, and etch.It's no OSH park, but not bad for 20 minute turnaround.

author: IconicPCB
author_rank: Super Contributor
timestamp: May 09, 2018, 08:24:49 pm
content: Voronoi algorithm is a great way to utilise available copper in a high current design.I am presently lookng at a multilayer approach to implementing a power distribution board ( fuses and relays ) in an automotive application.The approach is to use Altium as primary design tool and follow that with a post processing through Topor to implement Voronoi like polygons in order to enhance the copper usage.

author: Eka
author_rank: Regular Contributor
timestamp: May 13, 2018, 02:56:58 am
content: Nice, thank you. It also saves on etching wastes.I've often used flood filled ground and power planes for reduction in etching wastes and milling time.If you are thinking of extensions, I can see the use for setting the minimum gap spacing around specific traces for handling high and low voltages on the same PCB. I can also see the need for no trace void areas for keeping input and output voltages isolated as is done for PCBs used in AC line powered SMPS and isolated SMPS. No trace void zones likely being needed by more people. Not many hobbyists play with very high voltages on PCBs.

author: a59d1
author_rank: Regular Contributor
timestamp: May 28, 2018, 09:08:45 am
content: Neat project. Why did you pick Javascript in particular?

author: Pugbutt
author_rank: Contributor
timestamp: July 25, 2018, 01:02:17 am
content: Quote from: a59d1 on May 28, 2018, 09:08:45 amSorry for the very late reply. I picked Javascript because I thought that would be the most accessible form for many different platforms and OS's.
CircuitMaker Component Libraries? - Page 1
Forum section: electronics / general

author: Pack34
author_rank: Frequent Contributor
timestamp: June 22, 2018, 09:22:22 am
content: I want to get back into some open source work and wanted to ditch Eagle in favor of CircuitMaker. I figured it would be easy to switch between CM and AD between OSHW and my job.I like to keep my component libraries meticulous. Such as "Resistor 0402 Yageo", "Capacitor 0201 Murata", etc. I can clearly see how to make PCB projects, but for components it seems to be just Octopart listings.Can you not make an integrated component library in CM? I know it's all supposed to be online and open, which is the point, but certainly I should be able to make an open source component library to support my open source PCB. Is this actually not the case? All components are just floating there in a single library in the cloud?

author: xjordanx
author_rank: Contributor
timestamp: June 22, 2018, 05:06:09 pm
content: CircuitMaker only uses the centralized library.Technically you can, by creating a new project, then using the "add existing to project" and browsing for your local library files.It's recommended that afterwards you use the schematic RMB feature "Link to Octopart" to commit them to the main library - at which point they are automatically added to your Favorites in the Libraries panel drop-down, and you can find them again more easily for other projects.

author: Simon
author_rank: Unknown
timestamp: July 10, 2018, 08:57:36 am
content: Don't expect to be using a particular manufacturer. Supply at the moment is atrocious. I just use generic codes for passives like "1K2R 0805 1%" with the assumption these are 150ppm or better. Then buy an entire real of whatever I can find.

author: Smokey
author_rank: Super Contributor
timestamp: July 23, 2018, 01:36:27 am
content: Simon is on the right track. The last step is to make yourself a cross reference spreadsheet or something and assign internal part numbers to each equivalent part group... so..R0001 = "1K2R, 0805, 1%, 150ppm" or whatever. Add all approved suppliers of that part as equivalent alternates. Then you can reference the "R0001" number on your schematics and BOMs. CM gets a copy of the cross reference spreadsheet, and everyone is happy.
power place connections/thermal pad - Page 1
Forum section: electronics / general

author: gogoman
author_rank: Regular Contributor
timestamp: July 21, 2018, 02:26:12 pm
content: Hi I have not layout a board in a while,Given a four layer board (inner: power ground) using smd components, can the connections to the inner layer be made directly or must a thermal pad/relief be used.Using a via with a angular ring of 20mil and hole of 10 mils, what expansion value is recommend for a thermal relief?If two thermal relief intersect, resulting in 2 out of 4 spokes connecting to the plane, does this pose a manufacturing issue.thanks

author: borghese
author_rank: Regular Contributor
timestamp: July 22, 2018, 07:45:10 am
content: The thermal relief are normally used with PTH componentsWith SMD pad there is normally a short track for connection to the power plane that act as thermal relief;
Mixed SMD and PTH board (Smd both sides) - Page 1
Forum section: electronics / general

author: ocset
author_rank: Super Contributor
timestamp: July 18, 2018, 04:12:08 pm
content: We are doing a PCB which has both surface mount components and through hole components on it.The surface mount components are on both sides of the PCB.What’s the closest that a surface mount pad can be to a through hole pad?

author: T3sl4co1l
author_rank: Super Contributor
timestamp: July 18, 2018, 04:17:01 pm
content: 0.0mm, if you don't mind your assemblers screaming at you.Anything more than that, depends on target cost, process, reworkability, reliability, etc.Tim

author: Deridex
author_rank: Regular Contributor
timestamp: July 19, 2018, 04:01:20 am
content: A assembler that works for our us, recommended once 4mm distanze between smd components on the bottom side and pth-pins.But i think that recommendation is to keep it most easily for the assembler. I think less is also doable, but i think you need to keep in mind, that the harder time the assembling guys have, the more expensive it will be.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: July 19, 2018, 01:36:47 pm
content: The DFM service I use, flags anything less than 150mil (~= 4mm). The guys who run the service, say that's a worst case condition for their house process, which is to use wave solder (preferring full wave, with selective wave as alternative). The clearance is for the fixture covering the SMT components. So the clearance is actually a cone frustum around the THT pad. The size of the cone depends on the fixture technology used: milled fixtures are cheaper but thicker than, say, formed titanium sheet.Or you can do a full-wave process (no reflow), which I think is going to be more common with wider pitch SMTs and high volume production.Tim

author: borghese
author_rank: Regular Contributor
timestamp: July 22, 2018, 07:03:09 am
content: For the production of the printed circuit board 10 mils are more than enough; I use 1mm and even less

author: tautech
author_rank: Super Contributor
timestamp: July 22, 2018, 07:19:41 am
content: Quote from: treez on July 18, 2018, 04:12:08 pmDetermined by the two pads voltage differential and nothing else.
How to interpret layout hint of LT3451 DC/DC converter - Page 1
Forum section: electronics / general

author: newto
author_rank: Regular Contributor
timestamp: July 20, 2018, 05:13:22 pm
content: I'm working on a board, and will be using an LT3451 DC/DC converter to convert from +5V to +30V, and I'm trying to figure out how to interpret the "Layout Hints".Is the attached diagram just for the actual component layout, or should there be large copper planes in the sameish design as in the figure (ie: should it have large blocks of copper instead of normal traces)

author: T3sl4co1l
author_rank: Super Contributor
timestamp: July 20, 2018, 11:23:00 pm
content: Yes, they provide the gray areas for a reason.More particularly, low current traces (SHUTDOWN, and the feedback node on R1 and R2) don't need to be any shape, and can be thin. The rest should be thick traces approximately as shown, or pours. The L1 pad will be mostly for thermal reasons; it doesn't need to be a thick trace for electrical reasons (because L1 is effectively a thin, very long trace, wrapped up, after all).Tim
Annular Ring Size - Page 1
Forum section: electronics / general

author: Ranayna
author_rank: Super Contributor
timestamp: July 16, 2018, 04:50:07 pm
content: Hi,i have just created my first, rather complex, custom pattern (Footprint) in Diptrace.It is a Molex RJ45 Jack. Here is the datasheet, which I also used for all measurements:https://www.molex.com/pdm_docs/sd/857891001_sd.pdfThe process of creating the pattern was straight-forward, if somewhat tedious. I set the Grid to 0.01 mm and plastered my sheet with measurementsEverything seems to be working out, at least according to the 3D model. After properly offsetting the model, everything fitsI have now a question though that is not specific about Diptrace. I want to know about the required minimum size of annular rings for the two pairs of power pins (P1/P3 and P2/P4 on the datasheet)Those two pins are only 1.47 mm apart, and therefore do not work with the same ring size of the other pins. Ironically, these are the power pins, which can have almost 60 volts on them at about 500 mA I think.Currently, I have these set up with 0.95mm hole diameter and 1.2mm pad diameter. With that, the clearance between the pads is just 0.27mm...Is that still ok? Those seem awfully close together...Greetings,Ranayna

author: Deridex
author_rank: Regular Contributor
timestamp: July 16, 2018, 05:55:39 pm
content: I can only recommend a bigger annular-ring-sizeI'm not 100% sure, but i think 0,35mm(As example:Hole 0,25mm; Diameter 0,6mm)should be minimum on basic layouts.Remember that you need to be able to work with that pads

author: Ranayna
author_rank: Super Contributor
timestamp: July 16, 2018, 08:59:09 pm
content: Yeah, the usability of that small ring is one of the things I worry about. But now that I think about it, that should be easily solvable by using rectangular pads. With those I think I could get away with making the pads just 1.1mm wide, increasing the clearance between the pads to 0.37.That setup would result in just 0.07mm copper at the narrowest place, will that become an issue for the PCB maker?

author: tautech
author_rank: Super Contributor
timestamp: July 16, 2018, 09:25:49 pm
content: 0.95mm hole size is massive and probably doesn't need to be so large. Try 0.8mm

author: Ranayna
author_rank: Super Contributor
timestamp: July 16, 2018, 09:40:40 pm
content: Hmm, the datasheet says 0.89mm +0.05/-0.03mm. I chose 0.95 to make sure the part fits.But... following your comment I measured one pin of the jack with a (admittedly cheap chinesium) digital caliper, and got 0.48mm...It seems I misinterpreted the drawing to mean pin size, whereas it seems to suggest hole sizes.
Through hole packages rectangular or oval pads - Page 1
Forum section: electronics / general

author: AlfBaz
author_rank: Super Contributor
timestamp: July 08, 2018, 02:40:51 am
content: I'm going through my libraries with the aim to standardize as much as possible.I've noticed that I have a mix of rectangular and oval pads on through hole packages and want to stick with one or the otherI do tear drop all tracks onto component pins where possible but if you are connecting onto one side only that leaves the other with 90 degree cornersPro's and cons anyone?For example in high speed/frequency do the sharp corners radiate more into neighboring pins/tracks.In the pcb etching phase are we more susceptible to acid traps?Any thoughts?

author: Dubbie
author_rank: Unknown
timestamp: July 08, 2018, 05:03:49 am
content: Wouldn’t you be better served in high frequency stuff by making the switch to surface mount? It’s really not hard!

author: tautech
author_rank: Super Contributor
timestamp: July 08, 2018, 05:53:57 am
content: Quote from: AlfBaz on July 08, 2018, 02:40:51 amKeep some things uniform, like IC pin 1 always rectangular so when viewed from the underside there's no mistake !Headers, similar.... positive and negative......always different ! Always indicate pin 1 with a different pad.Polarised caps......just the same ^^^Diode cathode.......always a different pad to anode !Some general advice but with the above applied.Passives = round.IC's = oval.Signal headers = ovalPower headers = squareYou develop your own style based on your needs but give a thought to someone else picking up you work and trying to follow it.While most of us rely on an overlay it's not on the underside of a TH PCB so anything that makes faultfinding/circuit tracing/reverse engineering easier is a win win.When I do a home etched PCB and hence no overlay many symbols are added into the copper, a few: +, Gnd, . (a dot for pin 1), K and so on. Even I/O names are easily etched.

author: AlfBaz
author_rank: Super Contributor
timestamp: July 08, 2018, 11:07:14 am
content: Thanks for the tips Tautech much appreciated@Dubbie... I don't always get to choose the parts. Available stock, price per unit, design certification, customer surplus stock, there are a plethora of reasons to use through holeI just wanted to know if there were any electrical or manufacturability issues that may favor one over the other
Reference book for PCB layout? - Page 1
Forum section: electronics / general

author: Frillo
author_rank: Newbie
timestamp: May 30, 2018, 08:35:53 pm
content: Hello,I just finished my degree in electronics engineering, and I'll be starting on my first real job in a month or so, where I will be doing some PCB layout (and other tasks).I have some experience doing PCB layout already, but I want to get better.So the question is:Can any of you recommend some book to use as a reference for doing PCB layout (if such a thing exists), or can you recommend other litterature, which outlines the dos and don'ts?

author: tautech
author_rank: Super Contributor
timestamp: May 30, 2018, 08:50:29 pm
content: Dave's guide gives good sound advice.http://www.alternatezone.com/electronics/pcbdesign.htmThere's further helpful stuff in his Wiki and forum:https://www.eevblog.com/wiki/index.php?title=Main_Pagehttps://www.eevblog.com/forum/eda/

author: IconicPCB
author_rank: Super Contributor
timestamp: May 31, 2018, 04:30:31 am
content: IPC publications are your friend

author: cat87
author_rank: Regular Contributor
timestamp: July 06, 2018, 11:59:35 am
content: I guess something a bit more concree and closer to what you're looking for would be Howard Johnson's High Speed Digital Design: A Handbook of black magic. You have basically everuthing you nees there, from doo's and don'ts to examples and calculations.Also try looking at his other book(s)

author: RomDump
author_rank: Regular Contributor
timestamp: July 06, 2018, 02:30:50 pm
content: Quote from: Frillo on May 30, 2018, 08:35:53 pm"Right the First Time, A Practical Handbook on High Speed PCB and System Design, Volume 1"There is also a Volume 2.https://www.speedingedge.com/products/right-first-time/
How long can I leave paste before ovening - Page 1
Forum section: electronics / general

author: Simon
author_rank: Unknown
timestamp: July 25, 2018, 10:41:36 am
content: I am placing a board and have found one part to be the wrong package. Can I leave in 24 hours until the replacements arrive or should I reflow now and then try to rework the parts in?

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: July 25, 2018, 10:44:10 am
content: Look at the paste datasheet, it will usually spec the working life. ISTR 24hrs is typical, but keep it cool.

author: Simon
author_rank: Unknown
timestamp: July 25, 2018, 11:05:58 am
content: hm they are not too specific:http://www.chipquik.com/datasheets/SMD291SNL10.pdf

author: Simon
author_rank: Unknown
timestamp: July 25, 2018, 01:14:48 pm
content: Parts are on order and the boards are in the fridge with all parts but the missing ones.

author: wraper
author_rank: Unknown
timestamp: July 25, 2018, 01:28:03 pm
content: Depends on the solder paste. For example I left GC10 for 3-4 days and it still was tacky and reflowed without noticeable issues. On the other hand some other pastes become dry and non sucky in a few hours.

author: wraper
author_rank: Unknown
timestamp: July 25, 2018, 01:34:49 pm
content: Quote from: Simon on July 25, 2018, 01:14:48 pmLeave them at room temperature for at least a few hours before reflowing to avoid issues with moisture.http://www.indium.com/blog/humidity-and-solder-paste-do-not-mix.php

author: Simon
author_rank: Unknown
timestamp: July 25, 2018, 02:05:01 pm
content: OK will do, fortunately this is all in the office and humidity is at 37% in the room. I'll also do a prolonged warm up in the oven, do a spot of 50-80C before bringing to 100 and then the reflow temperature.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: July 25, 2018, 03:07:26 pm
content: I think the main concern is screen life, once printed, the flux is still there even if the solvent has evapotared

author: wraper
author_rank: Unknown
timestamp: July 25, 2018, 03:25:31 pm
content: Quote from: mikeselectricstuff on July 25, 2018, 03:07:26 pmOnce solder paste is no longer tacky, you will have tombstoning problem or parts could even move off from the pads completely.
Inside a Huge PCB Factory - in China (JLC) - Page 1
Forum section: electronics / general

author: SimonR
author_rank: Regular Contributor
timestamp: June 14, 2018, 10:12:00 pm
content: mikeselectricstuff added this video to the thread "Any experience with JLC PCB house in china?"https://www.eevblog.com/forum/eda/any-experience-with-jlc-pcb-house-in-china/75/But its way too interesting to be hidden there, If you want to know about how board are made its worth a look.https://www.youtube.com/watch?time_continue=1&v=ljOoGyCso8s

author: bitseeker
author_rank: Super Contributor
timestamp: June 15, 2018, 05:02:59 am
content: Note: Also posted by Macbeth a couple days ago in the Manufacturing forum.https://www.eevblog.com/forum/manufacture/very-interesting-look-into-a-chinese-pcb-fab-by-strangeparts/

author: DutchGert
author_rank: Frequent Contributor
timestamp: June 21, 2018, 03:02:43 pm
content: To bad that dude presenting it has no clue what a PCB is and is overly enthousiastic.
PCB layout for cell phone Frequency Immune - Page 1
Forum section: electronics / general

author: bullonwheels
author_rank: Contributor
timestamp: June 19, 2018, 05:27:58 am
content: Hi Everyone,I am having issues with a unit disconnecting its RF BLE link when I take the unit close to a cell phone.Its a CC2531 IC with keypad on it.What are the major steps to be considered when laying out the single layer PCB.Things considered: Added a guard ring across oscillator circuits.Decoupling caps very very close to IC.No clock traces near power rails.Anything else ?I can share gerbers if needed.

author: David Hess
author_rank: Super Contributor
timestamp: June 19, 2018, 10:34:15 am
content: 1. Minimize the loop area of all signals including power. Usually this means using a ground plane.2. Limit the bandwidth at all inputs and sometimes outputs. Usually this takes the form of RF filtering.3. Shield sensitive lines and nodes. This might include putting the whole thing into a shielded enclosure and filtering inputs and outputs to keep conducted RF out.

author: dmills
author_rank: Super Contributor
timestamp: June 19, 2018, 11:22:32 am
content: All of the above, and usually you will need at least a two layer board to stand much chance, your loop areas will just be too big on a single layer design.Physically smaller components (especially caps!) are better at high frequency, there is much to be said for 0603 or 0402 instead of anything with leads.Note that by the time you hit 1.9GHz, the parasitic behaviour of components is in play bigtime if you are not careful, and every component looks like an inductor (except inductors that look like capacitors!).Regards, Dan.

author: hcglitte
author_rank: Regular Contributor
timestamp: June 20, 2018, 01:52:58 pm
content: Consider inserting a SAW filter (step 2 from David)
Adding a SIM card holder: On PCB vs. separate (data logger) - Page 1
Forum section: electronics / general

author: Martin F
author_rank: Regular Contributor
timestamp: June 15, 2018, 08:13:35 am
content: Hi all,We're developing a data logger with SD card and WiFi capability.Currently, this logger is able to connect to a WiFi hotspot, incl. e.g. a mobile phone or mobile 4G WiFi hotspot.Going forward, we'd like to offer a cellular option as part of the logger (which is used globally).We've considered three options:1) Build in a SIM card holder and functionality directly in the logger- Probably the most elegant solution, but we're unsure of the complexity involved and the cost2) Build a small module/device that functions as a mobile hotspot and power it via the same cable as the logger- Advantage is that users can buy it as a module only if they need it, hence beneficial if it's costly to add; however, less elegant than 1) as it'll create more clutter- Also unsure how difficult it is to build this device as a module from scratch and whether some good starting points exist3) Purchase a batch of premade mobile unlocked cellular hotspots (e.g. USB sticks) and power this via the same cable as the logger- Simplest and fastest-to-market, but also assume these are the most costly solutionAny advice/tips on what you think would be ideal and what we should consider in this?If you have any specific suggestions for components/hardware that we should consider, we'd be happy to learn as well!Thanks a ton,Martin
Voltage Regulator PCB design review - Page 1
Forum section: electronics / general

author: bulletbolt
author_rank: Newbie
timestamp: August 05, 2018, 03:14:33 pm
content: Hi all,Here I have a project for voltage regulator. This is designed to use in small boats where you would need 12v dc power supply for ancillaries.It's not a perfect design and sometimes I get various faults, some of them are mystique. If someone, who has more experience with voltage control, could have a look and tell their opinion would be highly appreciated. This is not something I do o n daily basis so need experts adviceThe questions I have raised is:What's the limiting AC inputWhat's the maximum DC loadAll this PCB being fitted into small rectangular alu tube and fully potted.Ideas and thoughts please

author: blackfin76
author_rank: Regular Contributor
timestamp: August 10, 2018, 08:58:53 am
content: It's not really a regulator, it's just a rectifier that skips cycles when the output voltage is higher than the setpoint. It's doesn't seem to include any overload protection so maintaining the current within safety limits is up to the power source.
Waterproof PU leather bag - risk of static electricity damage to electronics? - Page 1
Forum section: electronics / general

author: Martin F
author_rank: Regular Contributor
timestamp: June 26, 2018, 08:29:13 am
content: Hi all,We're considering to offer a leather bag (PU material) to help waterproof of our loggers at customer applications - cf. attached image.However, we're a bit in doubt whether this type of leather material may cause static electricity damage to our data logger?Would any of you have any experience on this?Thanks,Martin
routing ethernet and the PHY - Page 1
Forum section: electronics / general

author: Gibson486
author_rank: Frequent Contributor
timestamp: May 29, 2018, 06:43:23 pm
content: I am routing my first ethernet board. I founds lots of guidelines online (although some conflicting, so I need to tread carefully). One thing I cannot seem to find are guidelines for the PHY to the micro. I looked at a design from ST micro with their Nucleo board for guidance. Oh my....from the PHY to the micro, they seem to just route to get there how ever possible. Does this mean that there are no guidelines from the PHY to the micro? Isn't it still a high frequency signal on the TX(0,1) and RX(0,1) lines? Are there no guidelines from the Micro to the PHY?

author: Gibson486
author_rank: Frequent Contributor
timestamp: May 31, 2018, 12:06:16 pm
content: I am gonna guess that this something I should know? or there really is a lack of documentation? or I just need to find out the hard way?

author: AndyC_772
author_rank: Super Contributor
timestamp: May 31, 2018, 12:55:29 pm
content: I'm assuming that the interface you're routing is RMII.If so, then it's designed with good timing margins, which mean there are no specific requirements for length matching. You can tell this by looking at the data sheet for the PHY and having a careful look at the setup and hold requirements; IIRC the active clock edges are in the centre of the guaranteed window where data will be valid, so they can move around a bit without causing a problem.You need to follow general high speed layout rules, of course, but they're not specific to RMII.Gigabit Ethernet is a different issue altogether. If you're routing GMII (or another Gbit interface), then you definitely do need to consider the contribution from the PCB when you do your static timing analysis.

author: Gibson486
author_rank: Frequent Contributor
timestamp: May 31, 2018, 01:26:22 pm
content: Quote from: AndyC_772 on May 31, 2018, 12:55:29 pmThanks. RMII is correct. I had no idea what the stuff meant on the datasheet, but now I do. But yeah, I thought I needed to adhere to high speed design rules, which is why I was surprised by ST's demo board.

author: bson
author_rank: Unknown
timestamp: June 02, 2018, 02:39:54 am
content: RMII is only 50MHz. It's not particularly sensitive. The PHY to magnetics is 35MHz for 100M, also not particularly demanding. It's pretty much connect the dots and done.

author: tszaboo
author_rank: Super Contributor
timestamp: June 02, 2018, 07:31:46 pm
content: I've run RMII though a DIN 41612 connector, and it didn't seem to mind it. It is just a fancy multi-bit SPI . Though keep in mind, that something functional doesn't mean that it will go thorough any EMC compliance measurements. The design I made didn't need to do that.
New Here - Page 1
Forum section: electronics / general

author: mattventura
author_rank: Newbie
timestamp: June 05, 2018, 11:54:39 pm
content: Hi everyone,I am new to the site and I am looking for more information about PCB prototype designs & variations. Any info would be great!Thanks!Matt

author: Dubbie
author_rank: Unknown
timestamp: June 05, 2018, 11:56:59 pm
content: Did you know that there was a PCB made with over 6 layers?I hope this answer satisfies your question.
Doubt in the dimensions in the datasheet - Page 1
Forum section: electronics / general

author: electrowhiz
author_rank: Contributor
timestamp: May 30, 2018, 10:09:20 am
content: I am creating a footprint for the opamp LM358. I referred the datasheet for the dimensions. There I saw one dimension as 8*0.48. I couldnot understand what this 8* is. I have attached the image below. Kindly clarify the doubt

author: glarsson
author_rank: Frequent Contributor
timestamp: May 30, 2018, 10:15:18 am
content: All eight (*pads have the same dimensions.
LEDs: Best solution for data logger in Alu enclosure? (end plate holes) - Page 1
Forum section: electronics / general

author: Martin F
author_rank: Regular Contributor
timestamp: May 18, 2018, 07:22:54 pm
content: Hi all,We're developing a new data logger and need to select our new system for LEDs - and we'd love your inputs!Previously we've been using the below style, put some distance behind square 1x2 mm holes:https://www.mouser.dk/ProductDetail/Kingbright/APA3010SYCK?qs=sGAEpiMZZMseGfSY3csMkeytxqHAv00ASpxmArjtJq8%3dHowever, we believe better practices probably exist.Our aim is to find something that can...1) Easily be machine mounted by our turnkey solution on the PCBs, i.e. avoiding through-hole (i.e. assume we'll need SMD LEDs)2) Are low cost (<0.1$ per unit)3) Minimize dust etc coming into the enclosureWe've looked at something ala below, but find them a bit clumsy and expensive. Further, we were hoping to keep the LEDs fairly small (i.e. 3 mm seem a bit large)https://assets.alliedelec.com/c_scale,w_200,d_no_image.png/70534904.jpgAny good tips on how to best set something like this up?We need 6 LEDs in total, 2 in front end plate and 2 in back end plate (end plates are aluminium).Thanks a ton for your inputs!We'd love to see any good examples you might have seen or designed as well for inspiration!Martin

author: sokoloff
author_rank: Super Contributor
timestamp: May 23, 2018, 12:19:58 pm
content: I'd have a look into light pipes.Never used them myself (everything I do is low-volume), but this is probably the most common solution in volume manufacturing.

author: laseralex
author_rank: Contributor
timestamp: May 27, 2018, 07:18:43 pm
content: Martin,I agree with Sokoloff: definitely consider light pipes or light pipe arrays. I use them all the time to bring illumination from a board-mounted LED to a front panel. I happen to use panel-mount light pipes, but lots of board-mount devices also exist.-Alex

author: Martin F
author_rank: Regular Contributor
timestamp: May 27, 2018, 09:08:54 pm
content: Thanks all! Our current LEDs are about 0.09$ per unit and I’ve found it hard to match via light pipes on mouser and Digikey - but I’ll keep looking and consider a higher price!
What is the difference between these 2 orcad pcb designer standard promo - Page 1
Forum section: electronics / general

author: tolerl
author_rank: Newbie
timestamp: June 02, 2018, 12:31:48 am
content: What is the difference between these 2 orcad pcb designer standard promo other than price.https://www2.ema-eda.com/Extranet/96711/forms.aspx?msgid=3d7af603-95c2-4a31-8f2d-5dc556d72a00&LinkID=CH00096711eR00000262AD&utm_source=pcb007&utm_medium=text&utm_campaign=2018+free+orchttps://www2.orcad.com/Extranet/96712/forms.aspx?msgid=a227e4d4-10c0-4f69-beff-d9410fc738ce&LinkID=CH00096712eR00000073AD

author: slothsd
author_rank: Contributor
timestamp: June 02, 2018, 03:20:09 pm
content: Looks like the $430 one is perpetual so you can use it after 1 year but won't get updates or live support. The $299 one looks like 1 year only and will not work after 1 year. I am basing the last part on the lack of "perpetual" in the less expensive option.
Help finding the right WiFi antenna & connector for data logger - Page 1
Forum section: electronics / general

author: Martin F
author_rank: Regular Contributor
timestamp: May 15, 2018, 08:30:01 pm
content: Hi there,We're developing a small data logger where we need to add an external WiFi antenna.The enclosure is as in attached PDF drawing and we need the antenna to go out of the Ø6.50 hole on page 5/5.We've looked at the following that matches our technical specs, but not the size:Connector:https://www.mouser.dk/ProductDetail/taoglas/cab721/?qs=%2fv8iy7V9uix41yCF2gxgAA==&countrycode=DK&currencycode=DKKAntenna (Small):https://www.mouser.dk/ProductDetail/linx-technologies/ant-24-cw-rh-sma/?qs=K5ta8V%252bWhtZm2nPYHBDdAg==&countrycode=DK&currencycode=DKKAntenna (Large):https://www.mouser.dk/ProductDetail/microchip/rn-sma-4/?qs=3vk7fz9CmNwM0uJP168ecg==&countrycode=DK&currencycode=DKKA few pain points with above that we're trying to solve:1) The connector has a very long screw head, which means the antennas we can find leave a lot open (as the width of the end cap is only 1.5mm)We'd ideally want something that could avoid this problem.2) The wire that goes inside the enclosure from the connector is very long - we'd prefer something shorter3) The Antenna (Small) is unable to bend, which makes it less ideal for packaging etc.4) The Antenna (Large) is too large and exceeds the width of the product5) The outlined examples are all quite expensive - we're interested in a cheaper solution if one existsWe'd ideally like an antenna that can "bend" (ideally in all directions), but which is close to the size of the Antenna (Small).And ideally a connector that fits the antenna in our enclosure with only a 1.5mm end plate.We're rookies when it comes to WiFi antennas, so we'd love to hear any tips/ideas for this.Thanks a ton!Martin

author: stevelup
author_rank: Regular Contributor
timestamp: May 17, 2018, 06:30:06 am
content: Search for 'stub' or 'stubby' antennas - that's what you want for this in my opinion.If the SMA connector is protruding too far through your case, just put a spacer on the inside?Mouser is an expensive place to buy this stuff - depending on volumes, you'd be better off getting it from China.

author: Martin F
author_rank: Regular Contributor
timestamp: May 17, 2018, 06:33:36 am
content: Thanks for the tip - any Chinese retailers you can recommend ?

author: stevelup
author_rank: Regular Contributor
timestamp: May 17, 2018, 06:40:43 am
content: I'd start with AliExpress35mm stub antenna:-https://www.aliexpress.com/item/small-size-WiFi-Antenna-rubber-antenna-short-2-4GHz-Antenna-stubby-antenna-Zigbee-Antenna-RP-SMA/32827467388.htmlYou can get the pigtails from there for about 7 NOK
Free Altium viewer - Page 1
Forum section: electronics / general

author: ocset
author_rank: Super Contributor
timestamp: May 15, 2018, 07:38:01 pm
content: HelloOur PCB designer has made some faux pas in his layout. I need to investigate his work deeper and need to be able to "show nets" etc...i cant do this with a cheap gerber viewer. (gc prevue)Does Altium have a free viewer?Our PCB layout guy says it hasnt but i thought it did?Can he export Altium layout to Eagle so i can view it in my eagle pro?

author: tszaboo
author_rank: Super Contributor
timestamp: May 15, 2018, 07:42:33 pm
content: https://www.altium.com/altium-designer-viewerYou do realize, that this is first result in google?
Harmonized Commodity Codes: Finding the right match for our product? - Page 1
Forum section: electronics / general

author: Martin F
author_rank: Regular Contributor
timestamp: April 30, 2018, 11:33:53 am
content: Hi there Eevblog,We sell a CAN bus data logger, which is used to record data from e.g. cars, trucks etc. onto an SD card.We're often required to share a commodity code when sending shipments abroad to e.g. India - but we're unsure what harmonized code best matches our product.We've previously used a broad one for Electronics (9030.84.00) but have heard it would be better to go more specific.Our page is:https://www.csselectronics.comHope you can help!Martin

author: jolshefsky
author_rank: Regular Contributor
timestamp: April 30, 2018, 01:33:58 pm
content: I'm mostly bumping this thread with a "me too". I would appreciate a resource—someone I could hire to find the "right" code who does something more than just searching the codes for keywords (which I can do just as well.)For products that haven't existed before, it's a challenge. My company sells a measuring tool that is designed with power-generation turbine alignment in mind. Ultimately it is a measuring device, electronic, other which seems to be the best fit. You're probably on the right track, but I'd download the chapters of codes to find the best guess since sometimes it's buried in something you don't expect—like maybe computer equipment or automotive.

author: jc101
author_rank: Frequent Contributor
timestamp: April 30, 2018, 05:30:27 pm
content: In the UK part of the TAX office (HMRC) who deal with import/export have phone number and e-mail address you can use for queries, I'd be surprised it other countries didn't have something similar.I suppose if you were someone outside the UK, and looking to sell / import a product to the UK, you could ask them the appropriate code to use on your product.....I've used them before and they were quite helpful.https://www.gov.uk/trade-tariff

author: Eka
author_rank: Regular Contributor
timestamp: May 12, 2018, 08:32:43 am
content: Quote from: jc101 on April 30, 2018, 05:30:27 pmThe USA has similar. You can ask for a judgement on what harmonization code a product falls under, but there is a catch. The import inspector reviewing the shipment has the final word. It may be different.
OrCAD Capture + PCB perpetual license for low cost - Page 1
Forum section: electronics / general

author: hammy
author_rank: Unknown
timestamp: May 10, 2018, 12:22:02 pm
content: The same offer from last year is back (but only for North America):QuoteLink:OrCAD Capture + PCB

author: Eternauta
author_rank: Contributor
timestamp: May 10, 2018, 01:43:37 pm
content: I have just renewed the maintenance license for the same package configuration ..at twice the price!Why this (good) offer is only for north america?

author: DerekG
author_rank: Frequent Contributor
timestamp: May 10, 2018, 03:06:53 pm
content: Quote from: Eternauta on May 10, 2018, 01:43:37 pmFavourtism I guess. Just get a mail forwarding address in the USA & use a Google email address.One service provider is ReShip USA (costs $5 to join), but there are many more.

author: asmi
author_rank: Super Contributor
timestamp: May 11, 2018, 03:57:15 am
content: Quote from: DerekG on May 10, 2018, 03:06:53 pmThere is much simpler explanation - EMA is Cadence's distributor in North America. Hence their offer is for NA.
Prototyping fab that accepts ODB++? - Page 1
Forum section: electronics / general

author: DanielSkevington
author_rank: Newbie
timestamp: April 25, 2018, 10:23:40 am
content: I want to get a short run of some small, simple, 2 layer boards done. I don't have the original design files any longer, but I do have an ODB++ output which was previously used for manufacture. Ideally I would just like to send this to one of the "$5 for 10 prototypes" style fab houses as these are not complex/critical boards so there is no need to use a high end fab house and I cannot justify the cost associated with that, but I have not been able to find any of the cheap places that will accept the ODB++ format. Does anyone know of or can recommend anywhere?Thanks.

author: Rerouter
author_rank: Super Contributor
timestamp: April 25, 2018, 11:33:56 am
content: As its a small run, I would say run with the more expensive guys if they will take it, and while your at it ask them to send you back a gerber copy, if there software can read it, they can likely convert it for you, and would give you the option of cheaper fabs in future.

author: elecman14
author_rank: Unknown
timestamp: April 25, 2018, 12:54:08 pm
content: ODB++ to gerber converters exist. You could try converting back to gerber and see what the output is like. This is probably what the board house would do anyway. It might be better to do it yourself to save some coin and make sure the gerbers look OK before sending them to be spun.
Looking for a logic modeling / simulation tool - Page 1
Forum section: electronics / general

author: Sigmoid
author_rank: Frequent Contributor
timestamp: April 19, 2018, 02:53:20 pm
content: HeyI'm looking for a modeling tool that would help me quickly brainstorm and test discrete digital networks based on 4000 series chips.Mainly I'd like to see if my ideas are even humanly feasible, in terms of chip count.At this stage, I don't want to mess with a full-blown eda, and as far as I understand, there is no synthesis engine that would translate Verilog into discrete MSI-based logic - I did learn some Verilog back in the university, and I understand that would be the "pro" approach, but I'm slightly wedded to discrete MSI chips at this stage. If someone knows of such a synthesis engine, please do bring it to my attention.There are quite a few logic modeling / simulation tools, and some that I had a look at were completely useless for anything beyond grade school demos. Ideally I'd need a wide range of components such as PISO and SIPO shift registers, the ability to define buses, etc. I prefer free as in free speech, but free as in free beer (or a non-exorbitant cloud subscription) wouldn't be bad either, if it's worth it.Thanks a lot

author: PCB.Wiz
author_rank: Super Contributor
timestamp: April 25, 2018, 02:36:58 am
content: Quote from: Sigmoid on April 19, 2018, 02:53:20 pmHmm - you are probably best to look at CPLD design flows.The fitter report files from those, usually include the binary equations, and those you can visually map onto MSI parts, if you want to.Lattice CPLD flows have reasonable flows and reports, as do Xilinx.You could also look at Atmel/Microchip WinCUPL.https://www.microchip.com/design-centers/programmable-logic/spld-cpld/tools/software/wincuplThat's simpler than verilog, so is closer to Logic MSI to start with, and it has MSI macros, and is much smaller download than the full Verilog suites....The functional simulator is also ok for testing before building.
DesignSpark PCB to EasyEDA? - Page 1
Forum section: electronics / general

author: exco
author_rank: Newbie
timestamp: April 16, 2018, 12:38:16 pm
content: Unfortunately I cannot come up with a solution.Maybe someone already has a working process for moving a project from DesignSpark PCB to EasyEDA?

author: exco
author_rank: Newbie
timestamp: April 24, 2018, 09:59:45 am
content: I guess that leavesenterprise waitingstart from scratch