hybridfree/eevblog-posts huggingface dataset:
Panel Punch - Page 1
Forum section: electronics / projects

author: L_Euler
author_rank: Regular Contributor
timestamp: May 16, 2019, 10:30:13 am
content: Any of you folks know where I can get a manual Punch set for IEC 320 C14 power cord sockets? Or, if you have one, can I rent it from you. Marking, drilling, nibbling, and filing is getting old.

author: dom0
author_rank: Super Contributor
timestamp: May 16, 2019, 03:56:33 pm
content: I mark from a template (with a scriber), drill and file. Reasonably quick with good files.Edit: If your panels are aluminium (probably the case), loading the files with chalk keeps them from gumming up.

author: bd139
author_rank: Super Contributor
timestamp: May 16, 2019, 04:01:56 pm
content: I use a nibbler for IEC sockets. Comes out lovely and clean. Takes about 2 minutes.If I was to do more than about 2 I'd get someone else to cut it professionally.

author: MagicSmoker
author_rank: Super Contributor
timestamp: May 16, 2019, 04:54:23 pm
content: I *believe* the correct knockout punch for the rectangular hole from Greenlee is:https://www.greenlee.com/us/en/die-unit-rect-866x118220x300-60042There are likely other (less expensive) options, so look for a rectangular punch around 22mm high by 28-30mm wide.

author: L_Euler
author_rank: Regular Contributor
timestamp: May 16, 2019, 09:06:04 pm
content: Thanks guys. Good tip on chalking up the file. I usually wet file aluminum with Tap Magic for aluminum.
Panelise PCBs - Page 1
Forum section: electronics / projects

author: Christopher
author_rank: Frequent Contributor
timestamp: February 05, 2014, 06:49:27 pm
content: Any easy way to auto-generate panels (Either from Gerbers or Eagle)?Including mouse-nibbles, Router paths, Fiducials etc?I know the board house can do this for me, but I want a way of making a panel for Pick-n-place myself.PS: Yes, I do have to use eagle.

author: Pack34
author_rank: Frequent Contributor
timestamp: February 05, 2014, 11:41:45 pm
content: There's a script (should be in the vanilla Eagle install) called Replicate Board. This will array out your design for you but you'll need to add the fids and milling lines manually.
panelization software: gerbmerge ? - Page 1
Forum section: electronics / projects

author: madworm
author_rank: Frequent Contributor
timestamp: June 26, 2011, 07:34:26 pm
content: Has anybody testedgerbmergeyet on linux, specifically on opensuse?The setup routine doesn't want to finish and complains about missing content of the variable 'DistLib'. As I'm not familiar with python at all, I can't say much more about it. The author's site doesn't provide more info as well.Using MicroSuck or non-free software is not an option for me. Both due to idealism and lack of $$.

author: ejeffrey
author_rank: Super Contributor
timestamp: June 26, 2011, 07:47:40 pm
content: Yes, I got it working on ubuntu a few weeks ago. I had the same problem, and had to modify the install script. If I can reproduce what I did I will post the solution here.

author: firewalker
author_rank: Super Contributor
timestamp: June 26, 2011, 10:40:51 pm
content: I believe that you don't really have to install gerbmerge. You can download the source, extract it and run the gerbmerge.py file in the gerbmerge directory.The command ispython gerbmerge.py(python could be python2.7 in some cases) .gerbmerge needs those packets in order to work:python2python2-simpleparsepython-egenix-mx-base

author: gregariz
author_rank: Frequent Contributor
timestamp: June 27, 2011, 03:49:58 am
content: I've tried it but I couldn't get it to operate effectively on my gerbers. The most cost effective package that seems to work well for me is Fab3000

author: madworm
author_rank: Frequent Contributor
timestamp: June 27, 2011, 07:51:17 pm
content: Fab3000 surely looks very powerful, especially the options to modify the gerbers, add milling outlines, teardrops etc. are tempting.But it would be overkill for the stuff I do.Edit: or maybe not... oh, I don't know...

author: madworm
author_rank: Frequent Contributor
timestamp: June 27, 2011, 08:12:52 pm
content: Small success here ;-)Code:if sys.platform == 'win32' or ('bdist_wininst' in sys.argv):#DestLib = distutils.sysconfig.get_config_var('prefix')#DestDir = os.path.join(DestLib, 'gerbmerge')#BinDir = DestLibDestLib = '.'DestDir = os.path.join(DestLib, 'gerbmerge')BinFiles = ['misc/gerbmerge.bat']BinDir = '.'else:DestLib = '/usr/local/lib/python2.7'I had to hack setup.py and change the last line shown in the excerpt above. This suits opensuse systems.Also I could only make it work with 'SimpleParse-2.1.1a2.tar.gz'. The sourceforge page initially offers 2.0.0 as the latest version - which doesn't work. Oh and of course it says 'needs 2.1.0 or later' on gerbmerge's page... DOH.
Panelizing & Sub Panels - PCB Fabs Question - Page 1
Forum section: electronics / projects

author: benjones
author_rank: Contributor
timestamp: November 29, 2014, 02:15:58 am
content: Hi friends,I have been prototyping my PCB's with OSH Park for a while and I'm getting ready to put in my first large order and I wasn't 100% sure what other PCB fabs meant by panelized. Do they mean having different designs on a panel or multiple of the same design? I can fit 15 copies of my PCB on a 10x10cm panel. Would I select 1 for panelized?Here are a few screenshots of the pages for Seeed and Elecrow:http://imgur.com/a/ke5EAThanks for help!-Ben

author: Galaxyrise
author_rank: Frequent Contributor
timestamp: November 29, 2014, 03:52:36 am
content: Have you watched?

author: benjones
author_rank: Contributor
timestamp: November 29, 2014, 04:15:53 am
content: Hi Galaxyrise (Hail Sagan!), Yep! they are great videos. I've actually watched them twiceI'm just curious if I send a fab a panelized PCB with 15 copies of my board do I have to pay for panelizing my design for them to manufacture it? Is the PCB fab's panelizing cost only for unpanelized designs that the fab will panelize for you?Thanks!-Ben

author: marshallh
author_rank: Unknown
timestamp: November 29, 2014, 04:38:15 am
content: Some fabs charge a fee for the privilege of letting them make your already-panelized panel.Some accept single files and will be happy to panelize them for you according to their own requirements (usually around $50-100)The batch services like you mentioned tend the fall in the former category.Larger one-shot fabs are like the second.

author: benjones
author_rank: Contributor
timestamp: November 29, 2014, 05:00:17 am
content: That's no funSo you're saying Seeed and Elecrow will charge me for panelizing my already panelized board?Does iTead studio do that too?

author: sca
author_rank: Regular Contributor
timestamp: November 29, 2014, 11:44:19 am
content: In my (very recent) experience, Elecrow are fine with multiple boards in their 5 x 10cm etc deals, as long as you only separate the boards on the ident, and don't expect them to rout them or otherwise separate them. I've always done this bit myself and sent them a single 'unified' gerber set. I tend to leave 2.5mm or 100th between designs.This is fine for prototypes - no problem to separate with a hacksaw and file / router / big Aussie knife - but obviously no good for production.sca
PAPR (Powered air purifying respirator) power regulation and low battery warning - Page 1
Forum section: electronics / projects

author: Axiverse
author_rank: Newbie
timestamp: March 22, 2020, 07:33:28 am
content: I'm looking at making some PAPRs for some friends in the medical field. In principle it's quite simple, a 12v fans connected to some 18650 batteries. I will add a buck boost regulator to stabilize the voltage from the batteries to the 12v expected by the fans.I have two things I'm trying to figure out.1. How do I add some kind of warning light. I'm thinking about putting 4 16850 batteries in series directly and use that into the voltage regulator. I haven't found any modules that will allow me to warn on low voltage on batteries in series. Any ideas what the easiest way to do this is? I have found 1-8s voltage alarms, but those are per cell. I'm not sure how to have the alarm hooked up and have it output 14.7v combined. The regular that I have in mind requires 8V minimum.2. Do I have to do anything special to regulate the lithium batteries? I know they may discharge at different rates and there is logic in the charging, but is it safe to directly put them in series? How if I wanted longer battery life? Can I put 3 sets of 4 batteries in parallel?Thanks!
Paradox EVO192 - Home automation - Page 1
Forum section: electronics / projects

author: montyx
author_rank: Contributor
timestamp: February 14, 2020, 12:04:56 am
content: Long story short, I'd like to connect my EVO192 panel to my OpenHAB ecosystem, and I have some issues.The details:I have a new flat, and my uncle, who is an oldschool security expert lend me an EVO192 panel to test with my OpenHAB server. I felt luck, because I knew that this panel has a relatively good support by some great mind, who already reverse engineered the serial communication of the system.My current setup on a plywood is the EVO192 board itself. It's connected to the main line with a transformer. I have a K32LCD keypad connected already, and a reed door switch for testing reasons. The system is blank, I've got it without setup of the zones, so this is on factory default. I connected my computer with an FTDI module to the board serial port. Installed the BabyWare software to configure the board.On the end, my plan or to connect an ESP8266 NodeMCU to the serial with a logic level converter, and my RPI can communicate with the panel over WiFi, or with an Arduino Nano, and an ENC28J60 Ethernet shield (https://www.aliexpress.com/item/4000275319136.html) for better security.Fortunately as I mentioned there are more solution to connect the EVO192 to my OpenHAB. What I prefer is the PAI project:https://github.com/ParadoxAlarmInterface/paiIt has a great gitter community, and supports most of the features of the Paradox panels.I have an issue now. I was able to connect the board to my PC, and the BabyWare can see the board. It accepts the Panel ID, and password, but after then it's going to hang on the next step:Code:Installer login.What can cause this issue? I hope I have an expert around who can help me out.Thanks in advance!
parallel approximations - Page 1
Forum section: electronics / projects

author: aboubkr90
author_rank: Contributor
timestamp: January 21, 2025, 04:55:01 am
content: Hello everyone!I wrote a white paper and I need someone to review and help me refine it.Thanks in advance.Aboubkr Alrasheed.

author: moffy
author_rank: Super Contributor
timestamp: January 21, 2025, 05:12:16 am
content: If you want to patent as you stated in your PDF you shouldn't publicise before patenting, anything in the public domain can void a patent application.

author: xvr
author_rank: Frequent Contributor
timestamp: January 21, 2025, 12:33:09 pm
content: Already invented(More than 20 years ago)https://www.analog.com/en/resources/technical-articles/understanding-pipelined-adcs.html

author: aboubkr90
author_rank: Contributor
timestamp: January 21, 2025, 02:35:09 pm
content: Seems so.But why are they using it for 100Msps?With current fet latency, this thing can easily do 100Gsps!!

author: tggzzz
author_rank: Super Contributor
timestamp: January 21, 2025, 03:01:13 pm
content: Quote from: aboubkr90 on January 21, 2025, 02:35:09 pmSee Keysight and LeCroy scopes. Also check the prices, and probably export regulations.

author: xvr
author_rank: Frequent Contributor
timestamp: January 21, 2025, 03:08:52 pm
content: Quote from: aboubkr90 on January 21, 2025, 02:35:09 pmOne reason already said by tggzzz - prices and export regulation.Another drawback of such a design is that errors grow exponentially with each stage. Therefore, a very precise scheme is required, and this is the reason why the pipeline architecture uses not 1 bit, but 3-5 at each stage, and why its width is limited.

author: aboubkr90
author_rank: Contributor
timestamp: January 21, 2025, 04:01:28 pm
content: I kept reading the article.That's completely different.The term "stage" in pipelined ADC is an ADC.Here I'm talking about a single ADC with propagation between stages that are simple differential couples with Schmitt trigger outputs.Bit error in this design happens when the stage to stage delay is a considerable portion of the input signal. Which is also completely different to the bit error in pipelined ADC.

author: aboubkr90
author_rank: Contributor
timestamp: January 21, 2025, 04:03:58 pm
content: They're pipelining ADCs in series.I'm talking about operating ADC stages in parallel.

author: mawyatt
author_rank: Super Contributor
timestamp: January 21, 2025, 04:21:47 pm
content: If you want to see the SOTA in ADCs today (well back in ~2010 when we were still involved), check out the Non-Uniform-Sampling ADC (NUSADC) championed by Dr Mike Chen @ USC.This technique makes the most use of a small number of voltage parallel comparators and takes advantage of advanced CMOS scaling by digitizing the precise time the input voltage crosses a comparator threshold, thus digitizing the input inboth amplitude and time. This unique technique (amplitude and time digitizing) allowsPostADC conversion Anti-Aliasing Filtering in the digital domain.Best
Parallel charging lithium batteries - Page 1
Forum section: electronics / projects

author: WaldPinkler
author_rank: Contributor
timestamp: August 03, 2022, 08:07:08 am
content: I want to increase charge rate of my 12V 270Ah lithium bank.My inverter unit has a 60A charger. I now have a 1600W generator and want to increase the charge rate when using that.The charger is a mastervolt mass combi and has a jumper where 2 units can be parallel connected with a master and slave. There is no schematic or much technical info regarding the connection. These units are huge and very expensive ($2k+) so I want to avoid that.I don't understand the master/slave parallel connection electronically. I believe the manual said a 2nd unit's power should be matched with the other. (they sell higher power models).What options are there to increase the charging rate?Can I just connect another battery charger? It seems to work fine with multiple mppt charges working at the same time.
Parallel DC DC switching boards for higher current output - Page 1
Forum section: electronics / projects

author: Daniele
author_rank: Newbie
timestamp: October 02, 2017, 09:23:06 am
content: I'd like to use cheap XL4015 boards to have a maximum constant output of at least 5A. Using a single XL4015 board at 5A is not feasible since it overheats (inductor can go over 200°C!) and XL4015 must be well heat-sinked and also XL4015 efficiency drops a lot at high currents. So the choice is to use 2 x XL4015 boards in parallel. Knowing the related problems of parallel operation, I added a load sharing system using op amps, so that the output currents can be evenly shared by the two supply boards. The op amp outputs act on the feedback of each XL4015 board. Each board has an output diode to avoid negative output current.First op amp:--------------Of course the diode causes a slight voltage drop current-dependant. This is compensated by the first op amp, which operates to minimize the difference between a voltage reference and the voltage output measured after the diodes (where the actual load is connected).Second op amp:--------------The second op amp minimizes the voltage difference bewtween the two XL4015 boards, measuring their voltages before each diode. This should ensure equal load sharing. Differences in diodes can be neglected, since even a slight load unbalance around 2.5A per board will not be a big deal.Testing enviroment:-------------------For testing my idea I added one current sensor after each diode, so I can monitor the current output of each board. Corrent sensor is ACS712 hall effect sensor.Picture of prototype circuit:https://ibb.co/fmJJgGPower ON:https://ibb.co/ceoJgGLoad step response 0A to 5A:https://ibb.co/jCVW1GOutput voltage ripple around 5V is below 30mV:https://ibb.co/b814MGSchematic (capacitors are missing):https://ibb.co/iaaW1GOf course the current output could be easily extended with more XL4015 boards in parallel in a similar way.Any feedback is appreciated!

author: Gribo
author_rank: Frequent Contributor
timestamp: October 03, 2017, 05:19:19 pm
content: What happens if one of them fails?

author: Daniele
author_rank: Newbie
timestamp: October 04, 2017, 05:24:44 am
content: it depends on the type of failure, I see 2 possible cases:1) fails with switcher open: output voltage = 0, thus the whole load will be picked up by the other DC DC and eventually the fuse PTC will cut the current.2) fails with switcher closed: output voltage = MAX, thus the failed converter will pick up all the load. This will expose to the risk of overvoltage, thus I foresee an overvoltage protection which will shut down the whole thing by blowing the main fuse via SCR (not shown in schematic).
Parallel input/output constant current sink driver - Page 1
Forum section: electronics / projects

author: galvanix
author_rank: Contributor
timestamp: June 03, 2020, 07:09:52 pm
content: Hello!I'm currently working on a 7-segment LED clock and am looking for a constant current LED sink driver, ideally something like a ULN280A with constant current outputs.The seven segment displays I have are rather large (HDSP-C2L1) and have a max. forward voltage of around 9.2V according to the datasheet, which is why I would prefer constant current control over adding series resistors for every segment.The main feature of this clock is that it doesn't have a microcontroller, it's just a bunch of 74HC390s and 74HC08s for the counting stage.This is also the reason I don't want to use the usual culprits from TI because those all require a digital interface.The output of the counters is fed into 74HC4511s for BCD-to-7-segment decoding.The display brightness control uses a 74HC393 with an R-2R-DAC and a comparator to generate a PWM signal. The other half of the 74HC393 is used together with a 3-to-8 line decoder for multiplexing the displays by enabling them sequentially.The clock source is the 50 Hz mains frequency from a AC/AC wall-wart adapter.Because of the way that I want the finished product to look I don't want to deal with 230VAC on the board itself.TL;DR: Looking for a ULN2803A replacement with constant current sink outputs.Any ideas?Thanks!

author: Benta
author_rank: Super Contributor
timestamp: June 03, 2020, 07:34:50 pm
content: Check Toshiba. They have a broad portfolio of constant-current LED drivers.

author: galvanix
author_rank: Contributor
timestamp: June 04, 2020, 06:01:37 am
content: Quote from: Benta on June 03, 2020, 07:34:50 pmThanks for the suggestion, alas all of the stuff I can find are serial input devices (shift registers with constant current outputs).Edit:Okay so I've been thinking about this all day but haven't made any progress. Say I wanted to use something like an ST STP08DP05, how would I get the data from the 74HC5411 into that one?I've been playing around with the idea of using a 74HC165 parallel input serial output shift register to convert to serial and then use a ripple counter to count the 8 clock cycles it takes for a single transfer and then stop it based on that.How would I trigger the start of a transfer after one of my other counters in the counter chain rolls over?
Parallel isolation board for CNC  - Page 1
Forum section: electronics / projects

author: Sparkey_500
author_rank: Contributor
timestamp: March 06, 2016, 05:11:20 am
content: I would like to show off a project i've been working on, it's a inline plug in isolation board for the parallel interface.The circuit consists of optoisolators with selectable inverting or non-inverting outputs via solder bridges and component placement.So far i've got it working on direct 5v inputs, but sadly it doesn't seem to want to work on the parallel port. I think the problem has to do with the resistor values and the maximum current supply of the parallel port.Sadly I known just enough electronics to build stuff but not enough to work out whats causing the issue.

author: Sparkey_500
author_rank: Contributor
timestamp: March 06, 2016, 09:36:09 am
content: Here is a picture of the board, I got it made by breadboardkiller

author: awallin
author_rank: Frequent Contributor
timestamp: March 06, 2016, 05:38:03 pm
content: especially on laptops the parallel port voltages can vary a lot - try to measure it with an oscilloscope. if you think the high-state is 5V it may actually be 3V or 2.7V or something like that. also depending on the port it may require a pull-up resistor.

author: dadler
author_rank: Unknown
timestamp: March 06, 2016, 07:54:45 pm
content: In what way does it not work on the parallel port?Exactly which PC817 opto are you using?

author: Sparkey_500
author_rank: Contributor
timestamp: March 07, 2016, 07:18:10 am
content: I'm using a standard atx motherboard which has 4.35v (not 5v) on the parallel bus.I changed the settings in the software to active high (from active low) and i'm getting some signals out the other side.I also noticed that the X axis data gets through but the Y axis data doesn't, So i probed the Y axis signal and it's half the voltage of the X Axis.My CNC works fine without the isolator board in place, so i guess the computer and CNC side isn't the problem.I used optoisolators since they are 10c each and are simple to use. and my system only runs at 33KHz
parallel jaw electrical clamps ? - Page 1
Forum section: electronics / projects

author: coppercone2
author_rank: Super Contributor
timestamp: January 29, 2021, 08:00:37 am
content: Do they have flat parallel jaw electrical clamps for testing things like conversion coats?I am working on alodine, I am interested in the effect of immersion time (thickness) and electrical conductivity as related to press fit assemblies of aluminum. The best I could think of is to connect wires to brass blocks or something like that and use mass. Or to add wires to c-clamps, but I was wondering if there is a standard surface area surface finish electrical tool for doing this, like ESD-mat testing weights.

author: bill_c
author_rank: Regular Contributor
timestamp: January 29, 2021, 10:23:31 pm
content: Don't know, but this would at least have parallel jaws and may be better than a c-clamphttps://www.grizzly.com/products/grizzly-premium-milling-vise-5/g7154

author: coppercone2
author_rank: Super Contributor
timestamp: January 29, 2021, 10:35:48 pm
content: I wanted something for long strips, I do have machinists vises that are nice but I was thinking something less beastly. The closest thing I have to it is a bakalite parallel jaw vise, but it still weighs alot. If I were to make it, I would combine knipex mini parallel jaws pliers with a screw mechanism to tighten the handle. I suppose you can make a 'thing' that fits over a pair of those, with two sections of pipe that swivel around a little bit with a thread in between.
parallel LT1010 20 MHz medium power voltage/current source? - Page 1
Forum section: electronics / projects

author: sarepairman2
author_rank: Frequent Contributor
timestamp: February 21, 2016, 12:52:47 am
content: http://cds.linear.com/docs/en/datasheet/1010fe.pdfThese guys can run on +-22V power rails and it seems that they could be paralleled up severely so long they are water cooled.It would be easy to make a select switch to either put them in a voltage output or current output loop (look in datasheet for details), and even connect them to different op-amps with relay networks to get "tailored" amplifiers, i.e. switch in bandwidth limiting/chopper amp for a higher power lower bandwidth precision buffer, also easy to change input impedance on these circuits, etc.If I am crazy enough to water cool these guys, what is the absolute limit as to how many I could parallel up before like, parasitic circuit effects or maximum junction temperature is reached?It seems like a really easy way to build a medium power amplifier so long you are comfortable working with hydraulics.i imagine it like some kind of formula with the sigma that converges to 0 benefit per added amplifier asymptotically (and eventually goes negative?)also, how does noise look like with parallel buffers inside of a feedback loop? I know if you parallel op-amps you get a noise reduction that follows some kind of square root regression.

author: Kleinstein
author_rank: Super Contributor
timestamp: February 21, 2016, 09:04:57 am
content: The LT1010 is nice, for low power, but it gets expensive if you need more than about 2 in parallel.Inside a loop with an OP, the noise of the buffer does not really matter, noise is determined by the controlling OP. So using more buffers in parallel has essentially no effect on noise.A complete amplifier also need capacitors for compensation, so switching to different configurations get hard and parasitic capacitance limits the use for higher frequencies. As amplifiers are not that expensive any more, its usually better to have the different configurations as separate amplifiers.

author: ThomasDK
author_rank: Regular Contributor
timestamp: February 21, 2016, 08:02:50 pm
content: Why not save the hassle, and just go for a single LT1210?You get 7x the output current, almost twice the bandwidth, and a dedicated pin for bandwidth limiting.Thomas

author: sarepairman2
author_rank: Frequent Contributor
timestamp: February 21, 2016, 10:58:22 pm
content: Quote from: ThomasDK on February 21, 2016, 08:02:50 pmMaybe I was thinking more then 7x parallel?I would not be above putting like 30 of those LT1010's together if it worked. it is also current feedback.
Parallel MAC unit based on modified booth algorithm [Help needed] - Page 1
Forum section: electronics / projects

author: gstekboy
author_rank: Newbie
timestamp: November 01, 2014, 01:33:10 pm
content: The below diagram is the parallel MAC structure. In parallel MAC both partial product addition and accumulation take place at same time.The partial product summation + accumulation unit of above parallel mac is given below.(link to the image).My problem : When I give input to multiplier as 00000101(5) and 00001000( 8 ) what will be the values produced(P0[7:0],P1[7:0],P2[7:0],P3[7:0] And S0,S1,S2,S3 And N0,N1,N2,N3 that can be used as input of partial product generation + accumulation stage.The complete document is shared below.Please share your ideas.I need to continue my project based on your replies.Thanks.

author: gstekboy
author_rank: Newbie
timestamp: November 02, 2014, 09:55:04 am
content: any progress?Normally by modified booth algorithm partial products generated will be of length 16 bit for 8 bit multiplication operation.Here partial products are of 10 bit.How it will give final correct answer?
Parallel Resistor Equivalence finder based on your personal stock list. - Page 1
Forum section: electronics / projects

author: sleemanj
author_rank: Super Contributor
timestamp: July 19, 2013, 03:42:59 pm
content: There are plenty of resistor network finders out there, but I never came across one that worked off "just what I personally have to hand", they assume you have at least a full E24 or better set - if you are a cheap bugger like me, you don't keep a full set, just more common values in a few decades.So anyway, long story short, I wrote my own equivalence finder that considers only those resistors you actually have, and figured somebody else might find it useful, so I put it on the interwebs -Equivalent Parallel Resistor Network Finder Using Your Personal Stock List Of Resistors(it's a mouthful, but trying to be friendly to the future googlers here).Caution, you should use Chrome for best results. Firefox works as long as firebug is disabled. No idea what IE will think of it all.Scroll down the page to enter in the base values you have decades/partial decades of. Select the number of decades you usually keep. Enter in any holes in your decades. And any bumps outside of the decades. You can hit the "Save (sort of)" button and bookmark the result for next time.Once you've described your resistor stock, you can search for a desired value (you can enter it in the usual various styles people use - 1.0, 3k7, 1.5M, 0R5, 0.5R, 762913 ... you get the idea), specify how much error you will tolerate, choose when the search should give you a less-precise but less-resistors solution, the maximum number of resistors per stack, and if there are no solutions within your error tolerance you can select a Last Resort option to look for a solution of two parallel stacks in series.NB: The first time you hit Search it builds an array the possible stacks, so that can take a few seconds depending on the Maximum Stack setting.Anyway, there you go, hope somebody else finds it useful

author: GrandTheftAuto4life
author_rank: Contributor
timestamp: July 19, 2013, 08:02:35 pm
content: NiceFor a future update, maybe choosing what kind of network would be handy...

author: Smokey
author_rank: Super Contributor
timestamp: July 19, 2013, 08:26:47 pm
content: Cool. I wrote some python scripts to do this same thing a while back. They were nowhere near as clean or flexible as that though.Good job!

author: Lightages
author_rank: Unknown
timestamp: July 20, 2013, 11:46:26 pm
content: Yes I like it too. Thanks for the contribution!
Parallel RGB to MIPI - Page 1
Forum section: electronics / projects

author: CTCL
author_rank: Newbie
timestamp: February 02, 2025, 08:14:25 pm
content: I have been going at this for several months now. I am still quite new to the field, self-taught, and I am learning this as I go. I am trying to come up with a design where a MIPI DSI display is driven by the Sunplus/Tibbo SP7021 SiP (System in Package) that has an HDMI and parallel RGB output. The display being used is the Tailorpixels TOH323XVT-01Chttps://tailorpixels.com/product/3-23-inch-bar-amoled-with-on-cell-touch-262x928-mipi/that has a resolution of 928x262 and appears to have a single lane MIPI DSI interface.Options, available to individuals, for converting RGB to MIPI DSI are very limited from my experience. I contacted Toshiba about getting more information about the TC358778XBG RGB-MIPI bridge IC months ago but I never got a response. I have seen some options from Solomon Systech and Analogix, though sourcing such components at such a small scale does not seem to be possible. I recently came across the Rockchip RK628 series where the RK628F and RK628D are available on LCSC as of writing, though like other Rockchip ICs, documentation is limited.Another option I explored is to use an FPGA though the only MIPI DSI transmitter IP I could find was this from GitHub:https://github.com/skatanik/dsi_controller.The third option I thought of was to use an STM32 microcontroller with a MIPI DSI transmitter like the STM32F469AE that would be dedicated to driving the display. This may be the most complex option where I may have to consider external SDRAM, DMA and communication between the SP7021 and the STM32.

author: sd
author_rank: Unknown
timestamp: February 02, 2025, 09:46:44 pm
content: Csdn.net might have more info about the RK628. If you find something, you can use baidudownloader to get the files (for a small fee).If I recall correctly, GOWIN has free (for their FPGAs) MIPI DSI IP.
Parallel SDRAM - Page 1
Forum section: electronics / projects

author: majdgh
author_rank: Contributor
timestamp: February 14, 2021, 01:22:36 pm
content: Hello everyone,can someone please help me, how to connect multiple SDRAM like MT48LC4M32B2 in Parallel, I would use STM32F7 with FMC for Example, but what are the pins the should not be connect together.I have already done an example with 1 SDRAM but i don't want to make the PCB for 2 SDRAM and then figure out that something wrong is connected, because doing such a pcb is not very easy, because of lenghth and impedance matching and at lease 4 Layers, so i wanted to get first help.so if i connect All Pins in Parallel without CS# then edit the driver to choose which Sdram that i would like to write to, so is this correct or am i missing something here. Thanks for help in advance.

author: RoGeorge
author_rank: Super Contributor
timestamp: February 14, 2021, 01:44:48 pm
content: That is a dynamic RAM, so if it is left for more than a few tens of ms without refresh (or without reads - each read also refreshes the read page), then the information stored in that chip will be lost.CS will deselect the chip, this is correct, but something has to take care of the chip refresh. Since I never worked with STM32F7 and its FMC, I don't know how the refresh is handled there, but if you just de-assert the CS and let the memory without refresh, it will lose its stored bits.

author: majdgh
author_rank: Contributor
timestamp: February 14, 2021, 02:20:57 pm
content: Thanks for reply, you made me notice something else. i think even if i edited the driver and change the pins that configure the chip select, the self refresh rate is 4 clock of memory cycles, so if i make it 2 and connect them to together, the mcu may not be able to refresh 2 SDRAMs!
Parallel vs. Serial LDOs - Page 1
Forum section: electronics / projects

author: JohnS_AZ
author_rank: Frequent Contributor
timestamp: June 30, 2014, 06:20:47 pm
content: So, I have a 6V battery pack and I need both 5V and 3.3V rails. I have LDOs for both voltages.I could wire it: battery -> 5V LDO -> 3.3V LDO (regulators in series)orbattery -> 5V LDO -AND- battery -> 3.3V LDO (regulators in parallel)Both work. I'm trying to think through if one approach is superior to the other.Any thought?Thanks!John

author: rob77
author_rank: Super Contributor
timestamp: June 30, 2014, 06:55:33 pm
content: depends on the current draw (and related LDO heat dissipation) on those rails..

author: T3sl4co1l
author_rank: Super Contributor
timestamp: June 30, 2014, 06:57:16 pm
content: If you need really good regulation (tighter spec, cleaner ripple*), the chained setup is better.*Except that batteries have no ripple to begin with, so any noise comes entirely from the load. Relevant to SMPS though.Sometimes one or the other is better, based on anticipated load and relative choice of regulators. For example, if you have already selected a beefy 5V device, then you might want to spare some dissipation from the 3.3V reg by chaining.If you're drawing much current at all, you should be using a high efficiency SMPS anyway. Really the question is moot, because if you're drawing enough current that the regulator dissipations matter, you should be using an SMPS.And for that matter, it should probably be an over/under supply converter, like a SEPIC, to account for low battery conditions (e.g., a 6V alkaline pack is "empty" below 3.2V or so -- your 5V LDO'd rail is long gone by then!).Tim

author: JohnS_AZ
author_rank: Frequent Contributor
timestamp: June 30, 2014, 08:14:00 pm
content: Thanks for the comments.It's really low power.800mA nicad pack on a small solar panel for charging.Less that 30mA on the 3.3V rail, 100mA or so on the 5V (intermittent load).Using MCP1702 for both regs (250mA capacity, 625 mV typical dropout).John

author: dannyf
author_rank: Super Contributor
timestamp: June 30, 2014, 08:57:25 pm
content: Assuming that they are linear ldos, the 2,d approach provudes lower ripple on the 3.3v output, but higher dissipation on the 5v ldo.

author: dannyf
author_rank: Super Contributor
timestamp: June 30, 2014, 08:57:25 pm
content: Assuming that they are linear ldos, the 2nd approach provides lower ripple on the 3.3v output, but higher dissipation on the 5v ldo.
Paralleling cell phone chargers - Page 1
Forum section: electronics / projects

author: alah
author_rank: Contributor
timestamp: May 15, 2018, 01:41:32 pm
content: Hi, ALL; I have a bunch of cell chargers but I need more current output, so I thought that maybe I could parralel the outputs. Im attaching a diagram. Any ideas, THANKs, Alberto.

author: Ian.M
author_rank: Super Contributor
timestamp: May 15, 2018, 02:45:28 pm
content: It depends on their output characteristic - if the voltage decreases with increasing load current and they are initially well matched, you can probably parallel them directly. If however they are high output chargers and are designed to increase the voltage with increasing current to compensate for cable resistance, any attempt to combine them without enough series resistance to *ALWAYS* cause the output voltage to decrease with increasing load current, will be unstable with one of them ramping up until it either supplies all the load current or its over-current protection trips.However, you'd be better off either getting a charger rated for the job if its for USB charging, or if you just want a lot of current at 5V for experimental work, using a higher voltage wallwart (or even a laptop PSU) + an adequately rated step-down (buck) DC-DC converter module from EBAY or Aliexpress.

author: Richard Crowley
author_rank: Super Contributor
timestamp: May 16, 2018, 06:13:29 am
content: If they are all IDENTICAL chargers/sources, it MIGHT work. But it would be a major kludge and not recommended.If they are different, its not even worth fooling with.I agree with @Ian.M, just getoneof the proper size. They are pretty cheap or even free if you shop/recycle properly.

author: Nauris
author_rank: Regular Contributor
timestamp: May 16, 2018, 05:55:51 pm
content: Should work as per diagram. Diodes are likely not needed for most normal small chargers. Using thin, long and equal lenght cables likely suffice for current sharing resistors.

author: james_s
author_rank: Super Contributor
timestamp: May 16, 2018, 09:18:15 pm
content: This is one of those things you can often get away with doing, but it isn't really a very good idea. I would suggest only doing it if you don't care if you blow up the chargers. It will usually work ok, but it might not.

author: german77
author_rank: Regular Contributor
timestamp: May 17, 2018, 01:51:58 am
content: Cellphones chargers will not blow or fail if you connect them in parallel, most likely one of them will work harder than the other, but I wouldn't use them to charge my phone.For general protoboard electronics it's fine, for high currents use a proper sized one.
Paralleling FETs in a SMPS? - Page 1
Forum section: electronics / projects

author: incf
author_rank: Frequent Contributor
timestamp: March 24, 2025, 04:02:13 pm
content: I've got a SMPS inverter design that has 1x PFET and I want to modify it so that it has 2x of the same model of PFET in parallel.The gate drive can handle itI'm worried about oscillation.What can I do to determine if there is any risk of oscillation?How can I mitigate that risk? (ferrite beads on one or more FET terminals seem to be popular)https://www.ti.com/lit/ab/slpa020/slpa020.pdf?ts=1742814301139source one says gate resistors are the primary considerationI'm considering two routes (1) have one gate drive and two FETs and (2) have two gate drivers and two FETs. I prefer (1) for space reasons.

author: David Hess
author_rank: Super Contributor
timestamp: March 24, 2025, 05:59:29 pm
content: Ferrite beads close to each gate connection can also be used. A low value resistor is usually less expensive.

author: youngda9
author_rank: Regular Contributor
timestamp: March 24, 2025, 06:42:46 pm
content: I would suggest that you choose #1 and test it to ensure it functions properly. Shouldn't be an issue.

author: Siwastaja
author_rank: Super Contributor
timestamp: March 26, 2025, 07:37:05 pm
content: Test first with simple hard-wired parallel connection. Single gate driver. Single Rg. I have seen it used a lot, e.g. on older motherboards. I have also done that myself a few times. Never a problem.If you are going to use two gate drivers, then I'd recommend not stopping there; e.g., if it's a DC/DC converter, then also duplicate the inductor and make it a true polyphase converter.

author: incf
author_rank: Frequent Contributor
timestamp: March 26, 2025, 07:49:31 pm
content: Quote from: Siwastaja on March 26, 2025, 07:37:05 pmWhat if I do use two gate drivers, one per PFET? (suppose the inductor is the right size, etc.)
Paralleling R for increased reliability in HV. Opinions welcome - Page 1
Forum section: electronics / projects

author: johm
author_rank: Contributor
timestamp: July 03, 2024, 04:57:29 pm
content: Hello! Came across this dilemma while designing an AC 240 V 50 Hz mains filter. When this circuit is implemented on a PCB with standard parameters, which option do you believe is most reliable in terms of:Parameter variabilityThermal dissipationRouting complexityBreakdown voltageFailure modes of specific resistances (short circuit, open circuit, drift)Resistors are1W 2512 SMD.It is basically a thought experiment as the difference is apparently minimal, but IMHO worth exploring.Cheers

author: moffy
author_rank: Super Contributor
timestamp: July 04, 2024, 12:48:44 am
content: There is no effective difference between the two as you suspect.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: July 04, 2024, 01:24:50 am
content: I disagree. In failure modes there are significant differences. For a simple example look at a fail open of R2. In the left hand case this results in a resistance across the line of 150 ohms, with 2/3 of the line voltage across R1. Power dissipation in R1 nearly doubles. In the right hand case the resistance across the line is 200 ohms, with the voltage across R1 remaining the same at 1/2 the line voltage and no change in R1 power dissipation. There are similar differences of other failures.Whether this makes a difference depends on the components chosen and the goals for the circuit. In general I would choose the right hand configuration.Power dissipation in the no faults case is only marginally changed, with the change all due to the actual layout and copper used for routing. It may go up or down.

author: Kleinstein
author_rank: Super Contributor
timestamp: July 04, 2024, 05:40:11 am
content: In this application the current is mainly set by the capacitor, not the resistors. So for the current and power to the remaining resistor there is essentially no difference. Usually the resistors are way more reliable than the capacitor. One may want a fusible resistor and not an oversized resistor, though this would be required only with a non X rated cap.The more failure prone part is the capacitor anyway.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: July 04, 2024, 10:28:16 pm
content: Kleinstein is right. I was over hasty, only looking at the changes in your proposals, not the overall circuit. In that light it seems that substituting four resistors for one is questionable since the voltage drop across the resistor(s) is modest and there isn't any other big change that occurs on failure of a single resistor. Hence Kleinsteins suggestion to use a fuseable resistor to cover the case of the capacitor failing short. The multi resistor approach can only help reliability if for some obscure reason the corner of your filter is very critical.
Paralleling Resistors - Page 1
Forum section: electronics / projects

author: geekbot
author_rank: Contributor
timestamp: May 30, 2014, 02:06:16 pm
content: This might sound dumb! I am making a dummy load and since I didnt get a higher watt resistor of 1 ohm, i tried to parallel 15 15ohm 2 watt resistors to get 1 ohm 30 watt resistor. My multimeter read the resistance of single resistor as 15.6 ohms. So I tried paralleling 16 of them and I am getting around 2 ohms WTF! The only logical explanation might be I burned some of the resistors when soldering but that too a 2watt resistor?

author: Andy Watson
author_rank: Super Contributor
timestamp: May 30, 2014, 02:08:24 pm
content: What does your multimeter read when you short its leads together?

author: sleemanj
author_rank: Super Contributor
timestamp: May 30, 2014, 02:22:32 pm
content: Resistance of your probe wires. Accuracy of your meter. Cleanliness of your probes. Cleanliness of the resistor leads. Contact resistance between the probe and leads....It all adds up.

author: geekbot
author_rank: Contributor
timestamp: May 30, 2014, 02:51:27 pm
content: I tried measuring current by supplying 5.2v and the current was 2.6A which makes the resistance around 2ohms

author: geekbot
author_rank: Contributor
timestamp: May 30, 2014, 02:54:38 pm
content: Quote from: Andy Watson on May 30, 2014, 02:08:24 pm0.9 ohms, its a cheap multimeter, and i dont trust it's values that why I tried measuring resistance using current and voltage

author: robrenz
author_rank: Super Contributor
timestamp: May 30, 2014, 03:14:11 pm
content: At low resistance values you MUST consider the resistance of the paralleling connections. They add up fast and can also give very bad balance of power among the resistors. The topology of parallel connections can make huge differences in the actual resistance and balance of wattage per resistor. Also remember those connections are usually copper with a very high TCR which means your resistance measurement with a meter will not match the actual full load at temperature resistance

author: geekbot
author_rank: Contributor
timestamp: June 01, 2014, 07:02:22 pm
content: Looks like my PC SMPS was not working properly, the 5v rail dipped to 3.8 v when under load!! Thats why I was getting around 2ohms! Now It's around 1.2!
Parallelling Mosfets to increase power capacity and heat dissapation - Page 1
Forum section: electronics / projects

author: ThermallyFrigid
author_rank: Frequent Contributor
timestamp: January 21, 2022, 03:30:56 am
content: Hello,I have several circuits that utilize only one Mosfet (both are dummy load capacity testing devices) and one problem I often run into is overloaded Mosfets due to current and the heat generated.To relieve the load and reduce the heat (while also increasing the current capability Mosfet Paralleling is a common solution.Unfortunately, there can be an unwanted side effect to doing this if not careful and that is parasitic Oscillations.I'm wondering if anyone has worked with that and can tell me how easy it is to get this oscillation and best strategies to avoid it.Thanks

author: T3sl4co1l
author_rank: Super Contributor
timestamp: January 21, 2022, 03:54:35 am
content: Well, more importantly, current balancing, in a linear application.We had several threads on this recently, covering the topic. e.g.https://www.eevblog.com/forum/projects/current-sinkdc-load-control-circuit/Oscillation is mainly a matter of adequate series gate resistance. Or with the controller, compensation.Tim
ParanoiaBox - Page 1
Forum section: electronics / projects

author: profdc9
author_rank: Frequent Contributor
timestamp: March 23, 2020, 02:01:54 am
content: Hello,I have created a standalone cryptography device that one can compose messages with, encrypt them, decrypt them, and read them all without a PC. It uses a bluepill and performs AES256 encryption as well as EC25519 cryptography. The device connects to a television and a PS/2 keyboard. It encrypts and decrypts to separate SD cards. Some pictures are below. You can get the full details athttp://www.github.com/profdc9/ParanoiaBoxIt is an experiment to see how small an attack surface a self-contained cryptography device can have. I have attached photos of literal screenshots of the television.Enjoy!Dan

author: DenCraw
author_rank: Contributor
timestamp: March 05, 2021, 11:58:04 am
content: hi Dan...I am interested in sending commands and receive the responses to and from a Siemens s7 1200 plc. using UDPI have already done all the protocol in simple text in UDP.In order to provide "some" sort of security I was planing to make my own cipher but with keeloq method,... again some sort.I am very overwhelmed by the info about encryption...I would like to have a simple encryptor, having the seed in both terminals (pc and s7), but the NEW password is sent in the last message.if the message is lost or corrupted or the device is having an attack,.. well i am lost here. perhaps, the PC must send a new message with a master password. and reset the cycle of passwords.. i don't know..I want to thank you for this project and i will continue in my search.If you get my idea I will appreciate any insight.Best regards.