hybridfree/eevblog-posts huggingface dataset:
Rise Time of Simscape MOSFET models (Matlab Simulink) - Page 1
Forum section: electronics / general

author: Random Model Maker
author_rank: Regular Contributor
timestamp: November 13, 2018, 03:02:05 pm
content: Hello everyone,I am modeling a H-Bridge to power a simple inductor in Simscape. The driving frequency is supposed to be 50kHz (Find the .slx file attached below, if you want to take a look).The issue I get is that the mosfets take a considerable time to turn on. The problems are that the mosfets that I will use later will turn on much faster than in the simulation, and that apparently the rise time does not depend on the frequency, it always appears to be about 1/4 period, which frankly leaves me out of ideas.I have tried several models, but the one that I could make work best is this one:https://de.mathworks.com/help/physmod/sps/ref/mosfet.htmlThe schematic itself is not that complex, it is just a square wave (50% duty, 10V ampl) into a S->PS into the mosfet. The adjustment of the duty cycle is done by a phase shift between the two half bridges. The Matlab release I am using is r2018b.Please note that I am an absolute Matlab noob and I have forced the functionality of Simulink/Simscape into my brain in the last 72 hours. I would normally not use Matlab to do this (normally I prefer some SPICE flavour), but this is required for my thesis.Thanks in advance for any help,Ivo
LTspice: THD error list to FFT display - Page 1
Forum section: electronics / general

author: Sylvi
author_rank: Regular Contributor
timestamp: November 10, 2018, 12:46:14 am
content: HiI use LTspice for circuit simulations and THD tests. Is there a way to convert the data of the error log showing the amplitude of the ten harmonics into a spectral or FFT display?Actually, I know it is done but how?Thanks

author: SiliconWizard
author_rank: Super Contributor
timestamp: November 10, 2018, 01:25:42 am
content: You can get FFT display from the waveform viewer: right-click -> pop-up menu -> View -> FFTThen you can select the waveform you want to perform an FFT on and additional FFT options (window, nb of points...)

author: Sylvi
author_rank: Regular Contributor
timestamp: November 10, 2018, 05:58:03 am
content: So simple!Thanks

author: SiliconWizard
author_rank: Super Contributor
timestamp: November 10, 2018, 11:49:53 pm
content: Quote from: Sylvi on November 10, 2018, 05:58:03 amDon't forget to select an appropriate FFT window depending on your needs, as the default is no window (thus a rectangular window) which would be appropriate only if you dealt with an integer number of periods of signal, which is rarely the case.
Help with gerber file format please - Page 1
Forum section: electronics / general

author: boylesg
author_rank: Newbie
timestamp: November 07, 2018, 11:25:38 am
content: Question for anyone familiar with PCB design and Gerber file format.I have been reading this document but unfortunately it contains too much engineering gibberish and not enough simple explanationX-2794000Y-254000D2*D14*Y-508000D1*X-2286000Y-762000D2*X-2540000D1*X-2794000D1*It seems obvious the the X and Y denote the x and/or y coordinates of a point in a polyline.And the D1 and D2 denote move to and llne to commandsBut hat are the units here? Are those integers referring to steps (as in a stepper motor) or millimeters or something else?But I can't figure out what all of this means.%TF.GenerationSoftware,Novarm,DipTrace,3.2.0.1*% // This is just the software that generated the gerber file%TF.CreationDate,2018-11-07T12:25:27+09:00*% // And the file date....all good%FSLAX35Y35*% // What is this?%MOMM*% // What is this?%TF.FileFunction,Copper,L2,Bot*% // Copper clad board but what do L2 and Bot mean?%TF.Part,Single*% // Single sided PCB....all good%TA.AperFunction,Conductor*% //%ADD14C,2.0*% // What do these two lines mean?%TA.AperFunction,ComponentPad*% // Get this....all good%ADD15C,2.3*% // My pads in diptrace were circles of 2.3mm diameter.....all good

author: ataradov
author_rank: Super Contributor
timestamp: November 07, 2018, 05:34:08 pm
content: Gerber files are described by the standard RS-274X. Here is the document:http://www.apcircuits.com/Portals/0/Assets/Downloads/the_gerber_file_format_specification.pdf?ver=2015-06-13-175030-363"%MOMM*%" - this sets the units to millimeters. "%MOIN*%" would be inches.

author: SiliconWizard
author_rank: Super Contributor
timestamp: November 07, 2018, 07:15:39 pm
content: Quote from: boylesg on November 07, 2018, 11:25:38 amThose are the two function codes that define how coordinates are to be interpreted in a Gerber file.MOMM => coordinates are in mmFSLAX35Y35 => omit leading zeroes, absolute, X and Y coordinates in 3.5 format (meaning 3 integer digits and 5 decimal digits)Strongly suggest you read the spec. doc as ataradov pointed you to.I'll give you the official Ucamco page though:https://www.ucamco.com/en/file-formats/gerber/downloads
converting images to gerber - Page 1
Forum section: electronics / general

author: LaserTazerPhaser
author_rank: Regular Contributor
timestamp: November 11, 2018, 10:15:00 am
content: Need to make copper layer using an imagetried thishttps://imagetogerber.wordpress.com/very inaccurate not even close to original dimensions of image I need to make an image go onto a copper layer. However there doesn't seem to be any tools for this.
A problem in a high speed PCB  - Page 1
Forum section: electronics / general

author: xzswq21
author_rank: Frequent Contributor
timestamp: October 05, 2018, 09:21:01 pm
content: HelloI have a PCB that a part of one of the high speed lines is not placed over the ground plane. the length is1300 milsactually it's LSB line of a high speed DAC (200MHz, 3.3V logic, the input capacitance of the DAC is 5pF).is there any solution to repair it?https://drive.google.com/open?id=1Em9Ov9_iE4yF5cVNMjFvx8r7M0IeYgcgas usual we have a 22 OHM resistor at the input of the line. can I replace 22 ohm with a 75 or 100 OHM resistor at the input of this line to reduce any ringing or overshoot? or can I scratch a part of this line and solder a 0402 resistor, for example here:https://drive.google.com/open?id=1ctwwOy-jWaZ-Q58fG6jOD9G_WamF4CaiThanks

author: KrudyZ
author_rank: Frequent Contributor
timestamp: October 09, 2018, 10:25:52 am
content: I would measure the actual impedance with a TDR.Then you can fix this to a fair degree by increasing the source termination resistor (your 22 Ohm) to match the line.Make sure you subtract the output impedance of the driver chip.Assuming you have sufficient setup time for the DAC, you should be OK. 1.3" is not all that long for a 200 MHz data feed.To verify you would need a very low capacitance probe right at the DAC with minimal ground to tip separation and feed length, else the probe forms a stub and you are no longer measuring the circuit itself.

author: Feynman
author_rank: Regular Contributor
timestamp: October 09, 2018, 09:24:27 pm
content: Do you actually encounter problems due to the impedance discontinuity and resulting reflections?

author: xzswq21
author_rank: Frequent Contributor
timestamp: November 23, 2018, 06:50:47 pm
content: Quote from: KrudyZ on October 09, 2018, 10:25:52 amQuote from: Feynman on October 09, 2018, 09:24:27 pmActually to have 50 OHM impedance, the distance should be 4 mils.so I have dug a slot under the line and very close to the line, now the distance is around 11 mils (now I can see some ground planes! I didn't cut them).then I have placed a copper shield in this slot (I have cut some shield from a RG-316 cable) so I soldered the shield to the near ground planes.on the other hand I have increased the damping resistor from 22 OHM to 50 OHM.I calculated the C and L and then modeled the lines as a lumped model in LTspice. I checked some situations, the overshoot of the line is in range (I checked the maximum allowed DAC's input logic level) and the rise time is good. for example with a 33 OHM resistor the level of overshoot is out of allowed DAC's input logic level.I know it's not perfect but better than that situation.
Altium Designer Copper Pads - Page 1
Forum section: electronics / general

author: rahandford
author_rank: Regular Contributor
timestamp: October 17, 2018, 06:57:00 am
content: Hi, Can some one please tell me the best way to make PCB tracks (as shown) as the package in Altium only has what I would call standard pads. Thanks

author: BradC
author_rank: Super Contributor
timestamp: October 17, 2018, 07:06:32 am
content: Are you talking about the polygons poured over pads/tracks or something else?

author: rahandford
author_rank: Regular Contributor
timestamp: October 17, 2018, 07:52:33 am
content: Yes, so do I just pour them as required?

author: BradC
author_rank: Super Contributor
timestamp: October 17, 2018, 08:15:24 am
content: Quote from: rahandford on October 17, 2018, 07:52:33 amThat's what I do. I'm now hoping someone clever comes along and points out how I've been going it wrong by demonstrating a clearly better and more efficient workflow. I can dream, can't I?

author: bugrobotics
author_rank: Regular Contributor
timestamp: October 27, 2018, 09:14:43 pm
content: Hi all, I thought I would mention my workflow as I just created a cruddy video showing my workflow for less than ordinary polygon pours in CircuitStudio. Recommend watching at 1.5x speed as I did zero editing. Should work just as well or better in Altium Designer. Hope that's helpful.https://youtu.be/BsuzJeKd-7k

author: radar_macgyver
author_rank: Frequent Contributor
timestamp: October 28, 2018, 01:24:32 am
content: I find it easier to use regions instead of polygons when I need an exact shape. With polygons, one has to fine tune PCB rules to prevent AD from trimming them in unintended ways.

author: bugrobotics
author_rank: Regular Contributor
timestamp: October 28, 2018, 09:10:55 pm
content: Yea, regions are easier until you need to remove the interior portion of text or something else with holes, internal shapes. Unless of course you know of a way to manipulate regions (hoping you do).
How to design a "dust cover" rubber bezel - Page 1
Forum section: electronics / general

author: Martin F
author_rank: Regular Contributor
timestamp: September 19, 2018, 09:17:47 am
content: Hi all,We're doing a small rubber bezel to "close off" our extruded aluminium enclosure from dust as much as possible.One of the challenges we have here is that we have an SD Card slot hole in one of our end plates. To cover this, we aim to create a small "extension" of the rubber bezel that goes up and covers this SD card slot. I've tried to add a cross-section to show what this would look like from the side - the black part is the rubber, while the grey is the enclosure end plate.However, to make sure this extension doesn't get loose, we also want to add a small strip/hole in the enclosure end plate where we can "press" a small part of the rubber bezel into - to make it stick. The rubber has a hardness similar to car tires.Our question is if any of you have any guidance on what kind of design works optimally for ensuring this sticks - and doesn't get too resistant to pressure into the hole?Also, we're not familiar with how much complexity a typical rubber mold can handle - any experience on this?Thanks a lot,MartinPS: Sorry if this is all nonsense. In that case I'll try to clarify further with drawings.

author: bugrobotics
author_rank: Regular Contributor
timestamp: October 27, 2018, 07:43:43 pm
content: What you show would most likely work. The only issue I see could be that you get incomplete seating of the plug in the aluminum plate or some bulging of the cover. I would most likely use a small raised feature as shown in the attachment. This raised area would allow the plug to stay on size or (preferably) smaller than the slot opening thereby reducing the likelihood of any bulging and, if designed properly, should provide a nice snug fit. Some undercutting is allowable with urethane/silicone molds.What is the small cut feature on the end of the plug shown in your first post?
Low cost EMI gaskets for aluminium enclosure? - Page 1
Forum section: electronics / general

author: Martin F
author_rank: Regular Contributor
timestamp: November 08, 2018, 09:55:19 am
content: Hi all,We're looking for a low cost EMI gasket set, similar to blue in the attached image.We were hoping to find something along the lines of 0.5-1.5 EUR per set (i.e. per 2 pieces).However, so far it seems closer to 10 EUR with most suppliers we've contacted.Do you know of any manufacturers that provide these at lower costs?Or alternative solutions we might consider? (we need our end plates to connect tightly with our body enclosure for EMC purposes).Any suggestions would be greatly appreciated.Best,Martin

author: Gribo
author_rank: Frequent Contributor
timestamp: November 08, 2018, 07:19:46 pm
content: First, this post should be in the projects and designs forum not in CAD/EDA.Second, What is your PCB size? It looks to be a standard extruded enclosure. If so, checkhttps://www.bopla.de/en/enclosure-technology/product/alubos.htmlfor enclosures with EMC seals.

author: Martin F
author_rank: Regular Contributor
timestamp: November 08, 2018, 07:30:27 pm
content: Sorry for the mistake - the enclosure has rounded corners - I've attached a pic.The other picture was just to clarify what I meant by EMI shields.Best,Martin

author: babysitter
author_rank: Frequent Contributor
timestamp: November 08, 2018, 07:41:39 pm
content: I never thought that i suggest WUERTH as cheaper.... but Wuerth. Have a look at WE-LT, for example.
OrCAD PCB: Search for part? - Page 1
Forum section: electronics / general

author: Pack34
author_rank: Frequent Contributor
timestamp: October 25, 2018, 06:35:43 pm
content: Surprisingly, Ctrl+F doesn't do anything. Is there a prompt to search for a REFDES to find a specific component in layout?

author: hammy
author_rank: Unknown
timestamp: October 25, 2018, 07:42:30 pm
content: Enable the "Find"-tab: Display -> Windows -> FindDock the Find window to your sidebar.Inside the "Find"-tab is a "Find by Name" input field. You also select what to find.If it doesn't zoom to the part deactivate User Preferences -> Ui -> no_zoom_to_object
PCB Material - Page 1
Forum section: electronics / general

author: JtroTechAB
author_rank: Contributor
timestamp: October 05, 2018, 06:45:28 am
content: Hello,See the attached Images for the reference.Want to know the material of PCB.

author: krish2487
author_rank: Frequent Contributor
timestamp: October 05, 2018, 11:12:31 am
content: There.https://en.wikipedia.org/wiki/Printed_circuit_board#MaterialsYou have the all the information you need ! :-)Now, was that so hard to google that yourself.Hope this helps.

author: JtroTechAB
author_rank: Contributor
timestamp: October 08, 2018, 11:45:26 am
content: Hello,They have mentioned list of materials.But it is not matching with the pcb which I have.As you can see in pic. one side is green and the other one is white.Want to know which type of pcb it is ? What material?

author: hv222
author_rank: Regular Contributor
timestamp: October 08, 2018, 04:50:16 pm
content: Probably CEM-1 or FR4. It's green, because of solderresist layer over the board.

author: mariush
author_rank: Super Contributor
timestamp: October 08, 2018, 05:01:59 pm
content: The white or cream boards used to be FR2 and the green circuit boards used to be FR4 (fiber glass based) ... but the green is just a colorant and can be used on other types of circuit boards.Easiest would to grab a knife and scratch the board and use a microscope to see what the board is made out of.

author: cjurczak
author_rank: Contributor
timestamp: October 15, 2018, 03:50:44 pm
content: Could also be a phenolic resin material, consistency similar to many plastics, usually single sided as shown. Tends to warp when heated to high, so it's use is limited in RoHs applications.

author: ThomasDK
author_rank: Regular Contributor
timestamp: October 19, 2018, 02:53:02 pm
content: Looks like CEM-1 or 3.
Accidentally Pasted Components Beyond Origin What Do I Do Please Help - Page 1
Forum section: electronics / general

author: exsequor
author_rank: Newbie
timestamp: September 27, 2018, 10:05:47 pm
content: Hi guys, I'm new to Altium and I think I accidentally pasted components when I tried to copy from one file to another. Im afraid this will make manufacturing difficult. Has anyone encountered this? What did you do to solve it? Did the manufacturing went well? Thanks I'm really desperate.

author: Mattylad
author_rank: Regular Contributor
timestamp: October 18, 2018, 08:41:14 pm
content: Can you select them and move them?If the mouse does not select them can you manually type their name (or name range) or use cross probing from the schematic, to select and move/delete them?
OrCAD PCB/Allegro: Different colors/opacity for traces and shapes? - Page 1
Forum section: electronics / general

author: Pack34
author_rank: Frequent Contributor
timestamp: October 18, 2018, 02:58:42 pm
content: Is it possible to have shapes be partially transparent in OrCAD PCB? Having all of these filled planes stacked on top of each other makes it difficult to see traces and features on the bottom of the board. Being able to use darker colors, wireframes, or different opacities would help.Is this possible?

author: AndyC_772
author_rank: Super Contributor
timestamp: October 18, 2018, 03:35:11 pm
content: Yes, just click on the 'color dialog' tool (Ctrl+F5), then select the Display folder and adjust the Shapes Transparency slider.

author: Pack34
author_rank: Frequent Contributor
timestamp: October 18, 2018, 07:17:48 pm
content: That is so much better...Thanks!
low cost, low performance flexible PCB substrates - Page 1
Forum section: electronics / general

author: ehughes
author_rank: Frequent Contributor
timestamp: October 16, 2018, 03:08:48 pm
content: Hello!I have a prototype built on on a standard PCB substrate (0.4mm .015"). It is a large design (10"x15") and has no active parts. I am looking for alternate substrates that are lower cost than fiberglass that are flexible. A finished thickness of .010" to .015" would be fine.1.) I need circuit traces on both sides. One side is a large plane. I am avoided silver printed ink as the resistivity is too high. 1/2oz or 1/4oz copper would be OK.2.) I am aware of standard flex materials such as Kapton, etc. I am looking for something that is lower cost.3.) I do not need a high performance material. In some cases the part will be throw away.4.) I can get standard FR-4 in in the 10"x15" size for about $5. I would like to push towards $1.50 in QTY 10k.I have used LED strips that are on a flexible material:https://www.adafruit.com/product/1138?length=1I have acquired these strips at a very low cost from AliExpress. I don't think the material is a fancy polymer such as Kapton. I would love to identify what exactly they are using.Thanks!
OrCAD/Allegro : Aligning components in layout - Page 1
Forum section: electronics / general

author: Pack34
author_rank: Frequent Contributor
timestamp: September 11, 2018, 04:21:32 pm
content: There seems to be a general alignment tool in Allegro but doesn't allow you to dictate how that alignment happens (Left, Right, Up, Down, etc).Is there another way to do this? In Altium I would select a series of components and then edit all of their X or Y values to be the same and then hit distribute. Can the same workflow be done in OrCAD/Allegro?

author: Neilm
author_rank: Super Contributor
timestamp: September 12, 2018, 07:05:02 pm
content: Highlight the components - right click on the one you want to align to and hit align. Look in the options menu for direction, alignment edge, spacing etc. I am assuming you are running a reasonably up to date version of allegro, I use 16.x at work.

author: U96
author_rank: Newbie
timestamp: October 16, 2018, 01:42:47 pm
content: for this to work, make sure you are in the 'Placement Edit' environment. otherwise you do not have this option in your menu
Gold plating through holes and vias. - Page 1
Forum section: electronics / general

author: semir-t
author_rank: Regular Contributor
timestamp: November 06, 2018, 10:23:34 am
content: I have a question and I can't seem to find an answer.When the PCB is gold plated is the inside of the hole plated to. By looking at the pictures of some boards I can see that there seems to be gold, but I don't know if that is general rule or it should be payed extra to manufacturer.

author: Niklas
author_rank: Frequent Contributor
timestamp: November 06, 2018, 07:10:44 pm
content: The gold coating covers all the exposed areas, so if the via holes are not covered with solder mask they will also get gold plating. However, the thickness might not be the same inside the via holas as on the solder pads.

author: GeoffreyF
author_rank: Regular Contributor
timestamp: November 06, 2018, 08:56:10 pm
content: If the hole is big enough to get wet, it will be plated. The metal is carried as atoms through an electrical field in a solvent. The holes are plated through before the board is etched into circuit patterns.
Allegro not placing parts at designated values!? - Page 1
Forum section: electronics / general

author: Pack34
author_rank: Frequent Contributor
timestamp: September 28, 2018, 10:48:44 pm
content: I just noticed a strange bug. To comply with the mechanical spec I've been selecting the mounting holes with the movement tools and the specifying the location using the command "x 103.0 5.0" but when I double-check with the INFO tool it'll randomly be off by up to 0.2mm in any direction.Is there a more precise way to place components?

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: September 29, 2018, 08:05:04 am
content: Doubt there's a bug here. First, "x" is not a true Allegro command, it is an alias that is defined by default to be aliased to the "pick" command. So check that this alias is still the same, since it is easy to change it.Second, I'm not sure what you mean by mounting holes, are you using a footprint or simply moving a via that you call a mounting hole?Third, Allegro lets you move things by several different references, but the info will give the x-y origin.For example, you can define a mounting hole symbol that contains a through hole pad. Simple. The symbol has a 0,0 origin, but you can place the pad anywhere you want inside the symbol, for whatever reason.So... you can move this footprint by the symbol origin in the layout, but if you do "info" on the pin instead of the symbol, you'll get an offset.Then of course, Allegro has etch and non-etch grids. Also, be careful in the setup. I've seen people converting mm to mils and playing with the accuracy and converting units a few times (playing around, I guess), and suddenly the whole database goes on a weird set of dimensions that can only be reset by refreshing all the symbols.Check all that before submitting a Cadence bug report.

author: Pack34
author_rank: Frequent Contributor
timestamp: September 29, 2018, 10:02:42 pm
content: It seemed to be more consistent when specifying more decimals. For example "x 5.000 5.000" as opposed to "x 5 5" produced much more consistent results. Maybe it was something odd because I'm working in mm instead of mils for board dimensioning, mounting holes, etc.For mounting holes I'm using a specific part that's a simple through-hole pad.

author: Neilm
author_rank: Super Contributor
timestamp: October 01, 2018, 05:48:45 pm
content: If you have snap to grid on it will snap to the nearest point - if where you want the holes is not exactly on the grid that would explain it.

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: October 02, 2018, 10:49:33 pm
content: No, Allegro snaps to grids when using the mouse, but pick at the command line overrides the snap.That's why it's important to figure out if the alias is still the same, and if the units have been converted back and forth. Things go off when you play around with units and precision... refreshing all the footprints can solve that issue.
Allegro: Macro for configuring the Find Filter? - Page 1
Forum section: electronics / general

author: Pack34
author_rank: Frequent Contributor
timestamp: September 30, 2018, 05:56:53 pm
content: Is there a macro or keyboard command to configure the "Design Object Find Filter"? It's tedious to switch between "All On" and just "Text" when placing a component and then positioning the silk REFDES properly. If there's a macro I can bind it to a button on my mouse and work a lot more efficiently.

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: September 30, 2018, 11:25:27 pm
content: Well, you should place the refdeses at the end of the layout IMO. You certainly can configure a macro. Here's how I do it:go to file -> scriptthis lets you record stuff to a file, when you're done go back to file -> script and press "stop".You can condense the commands down toCode:setwindow form.findFORM find all_offFORM find text YESsetwindow pcbdoneStick this in a text file, call it text.scr for example. Make sure your Allegro script path is set to point to the directory.Then define an alias with a ctrl key combination, I use ctrl q.Just typealias, press ctrl Q, thenreplay text.scrin the command window:Code:alias ~Q replay text.scrand press enter.(the ~Q is to show you it's a ctrl key combo.)Now when you press ctrl Q in the command window, it'll replay the script if it can find it.Of course, Allegro has many modes, and you'll only see "text" selected when you are in the move command.You can also use the super filter mode. It's a different way to work. Make sure that Allegro is showing "idle" in the left of the bottom status bar.Then right click somewhere empty in the pcb, you should see a little menu pop up, go to super filter and select text. You should see the find filter greyed out but showing text selected.Now check this out: you can simply click and drag (keep button pressed) text. You should see text be highlighted when just hovering over it. Go back to the super filter pop up and select OFF to go back to normal mode.
FlexBV  - Commercial boardview software for board repair (Louis Rossmann) - Page 1
Forum section: electronics / general

author: Inflex
author_rank: Regular Contributor
timestamp: September 29, 2018, 10:23:53 am
content: Many of you already know about OpenBoardView, which is the open-source, free for all MIT licenced software that is used a lot for board repair.There's now a commercial closed source fork, "FlexBV" which adds extra features such as;* PDF coupling;One of the biggest pains with the existing system was having to manually transpose/type what you wanted to search for between OBV and your PDF schematic, this is now* PDF Part Find;When you're looking for a part and you've run out of donors or all your existing donors have the part missing, the PDF Part find will let you locate which other schematics potentially have the item you're seeking* PDF Favourites;Set your favourite pages, no more page jumping just to get to the page of interest* Improved rendering;* Job tracking***Features in the pipeline;* Multimeter integration* Expected values/measurements for nets ( volts, diode-mode, ohms )FlexBV is available athttps://pldaniels.com/flexbvfor $149 USD (via PayPal) for immediate licence and download. NO DONGLE or INTERNET REQUIREDRuns on macOS 10.11+, Windows 7+, Ubuntu 16.04 LTS +
Up to 94% off ORCAD - Page 1
Forum section: electronics / general

author: EEVblog
author_rank: Unknown
timestamp: September 26, 2018, 01:31:12 am
content: David got this email:

author: s8548a
author_rank: Regular Contributor
timestamp: September 26, 2018, 04:57:18 am
content: WowLink please?I could only find this:https://www2.orcad.com/Extranet/96712/forms.aspx?msgid=8712bf44-12cb-441a-976d-6e8d4354dd69&LinkID=CH00096712eR00000073AD

author: EEVblog
author_rank: Unknown
timestamp: September 26, 2018, 05:40:46 am
content: Quote from: s8548a on September 26, 2018, 04:57:18 amThere wasn't a link, I guess you have to call them

author: JoseR
author_rank: Newbie
timestamp: September 27, 2018, 02:40:28 pm
content: Seems too good to be true.From who was the email? From Orcad.com or from a specific distributor?If it's true, I hope it's not for US only or something like that, like the offers from Ema-eda.

author: Eternauta
author_rank: Contributor
timestamp: September 29, 2018, 07:09:06 am
content: The new real-time pcb design features should be the "Sneak Peek" announced for October:https://www.orcad.com/sneak-peek
OrCAD/Allegro: Toggling transparency - Page 1
Forum section: electronics / general

author: Pack34
author_rank: Frequent Contributor
timestamp: September 11, 2018, 04:19:28 pm
content: Is there an easy way to do this? I typically prefer the transparencies but when concentrating on a specific layer I find it helps to make that layer opaque to verify planning and routing. Or is the intended approach to just hide the unwanted layers and then toggle the visibility back on when you're done?

author: Neilm
author_rank: Super Contributor
timestamp: September 12, 2018, 07:11:24 pm
content: I use Allegro at work, generally I use both approachs depending on exactly what I am doing at any given point. I don't know if it has been introduced in version 17, we are on 16 at work as not all machines would support running 17
ORCAD : Zoom to DRC error? - Page 1
Forum section: electronics / general

author: Pack34
author_rank: Frequent Contributor
timestamp: September 18, 2018, 10:53:34 pm
content: I'm used to Altium and Eagle. In those when the DRC is run you have a list and can click on line-items to zoom to the error. Is there a similar pane in OrCAD that I'm missing?

author: asmi
author_rank: Super Contributor
timestamp: September 19, 2018, 02:23:33 am
content: There are several reports in the "Export->Quick Reports" submenu, but I usually use "Check -> Design Status" window because it's a single central location that allows to see current board status - things like unrouted connections, unplaced symbols, or DRC status. Click on a small green-yellow-red box to the left of category to see the list. In that list there will be hyperlinks, when you click on it the editor will be centered on area in question. It doesn't automatically zooms in or out (at least I don't know how to make that happen), but I usually zoom beforehand.
Hobbyiest grade Schematic\PCB Software - Page 1
Forum section: electronics / general

author: uknerd
author_rank: Contributor
timestamp: October 07, 2018, 11:35:41 am
content: Good afternoon all - first post in a long timeI have recently used JLPCB for the first time - very impressed with their serviceI have been using EAGLE free for a while, and have been very happy, but have now found the size limit in the free version.Please can i ask what people recommend for either Free or sensible price Schematic \ PCB software such as eagleI have tried Kicad but could not get on with itI have no objections to paying a sensible price for such software but cannot justify the 1700 for altium designerThankyouUKNerd

author: bogdan2014
author_rank: Regular Contributor
timestamp: October 07, 2018, 11:57:51 am
content: Have you tried easyeda? It's quite nice.Sent from my Mi A1 using Tapatalk

author: sleemanj
author_rank: Super Contributor
timestamp: October 07, 2018, 12:06:57 pm
content: DipTrace

author: sokoloff
author_rank: Super Contributor
timestamp: October 07, 2018, 12:12:31 pm
content: I know you say you tried KiCAD and had troubles (I can understand that based on the UI).I also started with Eagle and later switched to KiCAD when Eagle got Autodesk'd. I found several of the YouTube videos helpful to walk through the process and after that, things made more sense, so you might try that.I have no dog in the fight, but if I look forward 5 or 10 years, I truly believe the KiCAD is going to be the dominant hobbyist and small/micro-business PCB design software. That's my basis for recommending giving it another go.The best video series I can recommend is "Getting to Blinky", which unfortunately has not (yet) been updated to the KiCAD 5.0 workflow.

author: uknerd
author_rank: Contributor
timestamp: October 07, 2018, 12:54:43 pm
content: coolThanks everyoneHas anyone used Circuit Maker - sharing designs is not an issue for meI am just watching dave's first impressions video

author: sokoloff
author_rank: Super Contributor
timestamp: October 07, 2018, 01:03:49 pm
content: Sorry, pasted the same video URL twice above. (now fixed but OP might not see it)The second video series I meant to link to is Getting to Blinky (KiCAD 4.0 unfortunately):

author: uknerd
author_rank: Contributor
timestamp: October 07, 2018, 01:52:09 pm
content: CheersWill take another lookJust tried a basic pin header -> resistor -> led schematic on circuit makerSeems a long process and so far don’t like it

author: MarkF
author_rank: Super Contributor
timestamp: October 07, 2018, 04:39:37 pm
content: +1 for DipTrace.The free version is limited by pin count. NOT board size.The free for Non-profit license gets you 500 pins.
solidworks flow fan models required? - Page 1
Forum section: electronics / general

author: coppercone2
author_rank: Super Contributor
timestamp: September 03, 2018, 09:31:23 pm
content: Totally forgot about this forum.Are there any high performance fans suitable for electronics use that are quiet, and have good flow (or a balance of therof) with manufacturers solidworks models?I am kind of playing around with solidworks flow but I am not going to try to model a fan. Am I SOL?Also, how about filter meshes? Like say the stainless steel mesh used as a air vent filter and RFI gasket in test equipment. Or a membrane that stops dust. Can you model these as a bunch of holes even though they are actually a bunch of chaotically organized fibers or foam-like material? I don't mean honey-comb (which I can figure out how to model) but the ones that kinda look like brillo pads or something.Edit: Found the porous media.How about fans?Or:If you just measure the CFM of the fan and the pressure drop, can you like make some kind of design choice (maybe some kind of short flow laminizer) at the cost of larger chassis to just use static numbers/surfaces/inlets in the flow simulation to maintain accuracy? I don't wanna spend alot of time on this because I already feel like a crazy person thinking about modeling airflow in a home electronics project. But I looked on some simulations online and the results were kinda nonintuitve so I at least want a clue. It's generally good practice anyway to have a bit of a tunnel after the fan to direct airflow to a specific region anyway right?Is there some easy formula or something with the RPM, Blades count, dimensions to estimate how much of a tunnel you need to average it enough so you can put a surface in solidworks as an inlet?Does a ducted/squriel cage fan fufill this requirement?
Critique my design help me improve please - Page 1
Forum section: electronics / general

author: jonwilhelmjr
author_rank: Regular Contributor
timestamp: September 03, 2018, 06:32:32 pm
content: Tell me what you think, how I can improve, what did I do wrong. I want to improve my PCB design and layout skills.Sent from my SM-N950U using Tapatalk
[OrCAD CIS] Move components or text to a specific location on schematic sheet? - Page 1
Forum section: electronics / general

author: Pack34
author_rank: Frequent Contributor
timestamp: August 29, 2018, 08:18:11 pm
content: I'm working on formalizing a schematic template and I want the page titles centered at the top of the page. I'm not seeing a specific move command in the schematic software like Allegro has for the PCB. I tried the command [x 13.8 2] to attempt to move it that way, but no luck.Is there a way to move something to a specific location in the schematic or simply align an element in reference to the schematic page instead of in reference to another element?

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: August 30, 2018, 12:11:31 am
content: view --> toolbar --> command windowobserve the commandsplay with commandsIt can be done, I just don't know the specifics.
which cad is the most advanced for power/thermal analyses - Page 1
Forum section: electronics / general

author: LaserTazerPhaser
author_rank: Regular Contributor
timestamp: August 22, 2018, 06:24:36 am
content: Are there any EDA's which excell in providing component power dissipation and even thermal rise? Im not talkin' bout resistors or BJTs rather IGBTs and the many different specialized IC's out there.

author: DerekG
author_rank: Frequent Contributor
timestamp: August 22, 2018, 10:29:42 am
content: You could take a look at DesignSoft's Tinacad:https://www.tina.com/stress-analysis

author: Rerouter
author_rank: Super Contributor
timestamp: August 22, 2018, 11:25:25 am
content: The closest you will probably find is "SolidWorks", most PCB packages these days should be able to export a 3D model of the PCB, If you filled in the materials with the original models, then you can just go add point sources of heat to them and run your simulation.If you want it to know from your simulation that this resistor is at this voltage / current, so is this hot, simulating electrically and thermally at the same time... tell me when you find it, because throw in digital stuff there and that seems like too many fields at once for commercial software.

author: Deridex
author_rank: Regular Contributor
timestamp: August 22, 2018, 04:07:20 pm
content: I think i remember a Plugin named PDN-Analyzer for Altium that can handle such stuff.Edit: Added name of the Plugin

author: Mattylad
author_rank: Regular Contributor
timestamp: August 26, 2018, 10:58:30 am
content: Whichever tool you use for this (ISTR CADSTAR bought one out too) it will very likely be expensive.I found that companies would prefer to pay a bureau that has the software to do it for them as this saved them having to buy and maintain the software and train to use it.That's if your wanting this in a commercial environment.

author: ahbushnell
author_rank: Frequent Contributor
timestamp: August 26, 2018, 11:42:58 pm
content: Quote from: LaserTazerPhaser on August 22, 2018, 06:24:36 amPLECS has a nice thermal modeling tool.But you can use RC equivalent ladder networks using SPICE for modeling.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: August 27, 2018, 05:06:42 am
content: If you have a model for the heatsink, you can represent temperature as a voltage, thermal time constants as RC networks, and implement everything in SPICE. Some manufacturers supply models with a TEMP pin, which connects to such a network.If you need complete 3D modeling including airflow (CFD), the cost quickly rises to 5 digits or more.Tim
PCB routing question  - Page 1
Forum section: electronics / general

author: yashrk
author_rank: Frequent Contributor
timestamp: August 16, 2018, 12:23:46 pm
content: Hey guys,I am working on an office project where we are using multiple SPI ICs on a single bus and as the orientation and pins of the IC is fixed I had to route the bus in the manner shown in the image. I am tapping these signal where there is an IC connected as shown in the image. The bus spans 310 mm long where the signals from the controller are inserted in the middle. SPI clock will be at <10MHz. the board is two-sided and has a ground flood fill in between them.Sorry I cannot share the whole layout as its an office project.1. I am concerned that the clock line going over the other lines may cause a problem, what are your views on that?2. Is there anything else I need to take care about considering the length of the bus? i.e. 310mm/2 = 155mm on either sideThank you,Yash.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: August 16, 2018, 09:06:10 pm
content: Stubs this short are only a concern with high speed interfaces, not SPI.The angled bits could stand to go, they just look ugly (some will call the acute angles acid traps, but that apparently isn't a problem anymore; so I stick with an aesthetic reason instead).Add stitching vias around the bus.If you want, add source termination resistors, at each driving pin (so, at master SCK, MOSI and CS's, and at slave MISO's). 47 ohms would be typical, or higher if you don't need super fast operation.Tim

author: Deridex
author_rank: Regular Contributor
timestamp: August 17, 2018, 03:41:01 am
content: I don't think that you need to worry about the SPI bus in therms of routing this way.For me it looks like the SPI has only little requirements to the routing. The only problem i remember so far, was with very fast rise&fall-times that were adjusted with a resisitor.

author: yashrk
author_rank: Frequent Contributor
timestamp: August 17, 2018, 06:05:54 am
content: Quote from: T3sl4co1l on August 16, 2018, 09:06:10 pmThanx for your comment, I have 47ohm resistors in series with each and every pin near the slave side as well as the master side I will then just populate the resistor on the master side, MISO on the slave side and will put a 0ohm resistor on the remaining pins. Or is it better to have 47ohm resistors on both sides?Regards,Yash

author: T3sl4co1l
author_rank: Super Contributor
timestamp: August 17, 2018, 07:14:28 am
content: Yeah, that'll be fine, the 47 and 0's.Tim

author: Mattylad
author_rank: Regular Contributor
timestamp: August 26, 2018, 10:54:24 am
content: Every time I have been to a pcb fab house this century - they have confirmed that acid traps ARE still a problem, just not as big as it used to be so it is still good practise to reduce as much as possible all angles of less than 90 degrees, such as those pictured in the Op.

author: yashrk
author_rank: Frequent Contributor
timestamp: August 27, 2018, 04:14:26 am
content: Quote from: Mattylad on August 26, 2018, 10:54:24 amYeah, I fixed that.
Help with PSU Power Traces (+/-12V, +5V) - Page 1
Forum section: electronics / general

author: Caterpiggle
author_rank: Newbie
timestamp: August 24, 2018, 09:31:44 pm
content: Hi guys,I've been working on a very simple power supply that provides 3 voltage rails. The +/-12V rails can pull 625mA each, and the +5V rail can pull 1.5A (2.75A at some points on the board). I've designed a PCB to allow for these currents, but I'm a bit worried since I don't know the standards for this sort of thing.The large square on the bottom is a thermal pad for the large DC-DC converter that provides the +/-12V rails. The thermal pad is connected to the ground pour on the bottom, with thermal vias to pull heat towards that side.The large traces are 2mm wide, and the smaller are 0.508mm. Some of the power traces I did by hand to provide more current (while still looking clean). Is this necessary, or possibly bad practice? Is there a better way to do this?I'm also concerned about the ground paths for some of the connections on the bottom. They have to run across the whole board and take some long paths. I made sure to make the thermals thicker for higher current.I appreciate any input or help you guys can provide.Thanks!
Allegro: DRC showing RED but no reported errors?  - Page 1
Forum section: electronics / general

author: Pack34
author_rank: Frequent Contributor
timestamp: September 30, 2018, 07:27:27 pm
content: I can go to TOOLS>UPDATE DRC and the DRC status bar is red. However, if I go to TOOLS>REPORTS and select the DRC Report and the Unconnected Pins report they both show no errors. I will note that this started happening after I switched from mm to mils.Any ideas on what report I could run to find out why it's showing as RED?

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: September 30, 2018, 10:33:35 pm
content: What do you call the "DRC status bar"?There are many sources of DRC. Go to setup->constraints->modes to see what's on or off.Display->color, go to stack-up, there are drc layers here too.display->status, this is the best place to look for errors: you can click on update DRC here and you can see sources of errors too.The secret of the status is that the little colored squares are buttons you can click on... Not obvious. What do they show?
USA 4G bands - which are most important? - Page 1
Forum section: electronics / general

author: Martin F
author_rank: Regular Contributor
timestamp: August 21, 2018, 07:51:43 am
content: Hi all,We're aiming to provide customers with a 4G USB router and we're trying to lock down which bands we need support for.From what we understand, in the US the below bands are used for 4G/LTE purposes:B2/4/5/12/30If we have a 4G USB router that only supports B2/4/5, will that be enough for good coverage across USA?Or do we need to have a version that supports all those bands?Thanks for your inputs,Martin

author: Bratster
author_rank: Frequent Contributor
timestamp: August 21, 2018, 03:57:32 pm
content: Here's a list of the US Cell phone bands that came up in a quick Google search.https:// blog.solidsignal.com/tutorials/lte-frequency-bands-u-s-canada-mobile-carriers/Edit: link is not working correctly for some reason. Delete the space between the slashes and the word blog.Edit 2: that list may be incomplete. Because I know for sure that T-Mobile also uses band 4.It would not be recommended to leave out support for some bands without heavy research to prove they are not used 99.9% of the time. That's only going to end up pissing off users.Sent from my Fi Moto x4 using Tapatalk
SharedPCB. A PCB manufacturer from China. - Page 1
Forum section: electronics / general

author: palpurul
author_rank: Regular Contributor
timestamp: August 17, 2018, 07:38:16 am
content: Hello,I was recently approached by a PCB manufacturer from China. The company is called sharedPCB and their price is somewhat competitive, capabilities are OK as well. I didn't see a lot of reviews about them. Has anyone ever heard of them or worked with them in the past? I've been working with PCBway since I was a student, should I give this manufacturer a chance?Link to their website:http://www.sharedpcb.com
Use of long pads on prototyping PCBs - Page 1
Forum section: electronics / general

author: petert
author_rank: Regular Contributor
timestamp: September 14, 2018, 06:01:57 pm
content: Hi,I have seen long pads at the borders of cheap PCBs you can get from amazon or ebay, but don't quite get what they are used for.See here for example:I would think they could be plugged into some kind of socket, like PCI/ISA/etc. cards, but I never found a matching socket/receptable, and they are rounded, unlike usual pads for such sockets.What would be a "standard" use for them? And what are typical receptors/connectors for them?

author: rx8pilot
author_rank: Super Contributor
timestamp: September 14, 2018, 06:08:24 pm
content: I think they are used for wires or headers. Not sure there is a specific purpose other than providing some alternate way of soldering something to it.

author: dferyance
author_rank: Regular Contributor
timestamp: September 14, 2018, 06:40:24 pm
content: I've used them to solder flat male headers to them. You can get angled headers through-hole but then the board can be in the way.
Dots and Dodges in OrCAD? - Page 1
Forum section: electronics / general

author: Pack34
author_rank: Frequent Contributor
timestamp: August 10, 2018, 08:50:52 pm
content: In OrCAD schematic, is there a setting hidden somewhere to implement "dodges" or "hops"? Meaning that when two nets on a schematic pass over one another that it'll do a little half-circle around the non-connected net to make it abundantly clear that the two wires are not connected.

author: Neilm
author_rank: Super Contributor
timestamp: August 11, 2018, 05:31:04 pm
content: Not that I am aware of (unfortunately).