hybridfree/eevblog-posts huggingface dataset:
Converting PTH to SMD - Page 1
Forum section: electronics / beginners

author: Arch
author_rank: Contributor
timestamp: August 06, 2014, 02:31:14 pm
content: Hi, I am going to be doing repairs to an old guitar pedal and in the process of learning how it works I was thinking of mapping the schematic out in eagle to learn more. Then I was thinking beyond this point. Maybe I will make my own clone of it and figured maybe I could use this as a chance to learn about SMD boards and componentsWhat is the general process in converting PTH boards to SMD boards?- Simulate in spice to find min/max voltages on components- Simulate in spice to find min/max current through components- Determine max power for components- Find equivalent/valid components in SMD form- Swap components out- Redo traces- Compact board layoutDoes this sound about right?Are there any good links on this topic that you know of?In case it matters, this is the schematic for the pedalhttp://www.geofex.com/FX_images/p180.gif

author: tautech
author_rank: Super Contributor
timestamp: August 06, 2014, 08:42:35 pm
content: I don't see any power issues for components for that schematic other than around the zener regulator. That's all I would check.Presumably all the pots and jacks are off PCB.You could make a custom footprint for these rather than standard to save more board space.Under 50 x 50 mm is achievable I think.

author: Arch
author_rank: Contributor
timestamp: August 07, 2014, 09:18:44 pm
content: Quote from: tautech on August 06, 2014, 08:42:35 pmPots, jacks are off boardDo you mean a custom footprint for the off board connections?

author: rob77
author_rank: Super Contributor
timestamp: August 07, 2014, 10:13:24 pm
content: no worries about max power... according to the schematic the current through the zener without loading the 3V reference is approx 0.6mA => approx ~ 36mW on the 10k resistor and ~ 18mW on the zener - that's half a bee's dickeven if you would short the 3V reference to ground, you would get 0.9mA through the 10k resistor and approx ~ 81mW - still well withing the 125mW max dissipation of a 0805 SMD resistor (or 100mW for 0603 size).i would suggest to completely skip the simulation and just focus on the PCB layout

author: Arch
author_rank: Contributor
timestamp: August 07, 2014, 10:14:58 pm
content: Quote from: rob77 on August 07, 2014, 10:13:24 pmHaha ok coolPCB layout is the fun part

author: tautech
author_rank: Super Contributor
timestamp: August 07, 2014, 10:24:20 pm
content: Quote from: Arch on August 07, 2014, 09:18:44 pmExactly
Converting PWM to analog - Page 1
Forum section: electronics / beginners

author: stafil
author_rank: Regular Contributor
timestamp: March 28, 2020, 03:16:35 am
content: Hi,Any traps for young players in the circuit below? I am trying to convert a 3.3V PWM signal to a ballpark 4V-12V analog signal. Looks fine in LTSPice, but wanted to double check with somebody experienced.

author: Zero999
author_rank: Super Contributor
timestamp: March 28, 2020, 10:54:30 am
content: It won't give a 4V to 12V analogue signal, but 0 to 13.2V. Connecting a P-channel like that will also result in oscillation, because it will add a considerable amount of gain to the loop. It will need some phase compensation.R7 isn't needed.The BSS84 will fry with 500mA of continuous drain current.https://www.onsemi.com/pub/Collateral/BSS84-D.PDF

author: stafil
author_rank: Regular Contributor
timestamp: March 28, 2020, 07:02:36 pm
content: Quote from: Zero999 on March 28, 2020, 10:54:30 amThanks!Any pointers regarding the oscillation and the phase compensation!Good catch regarding BSS84! Thanks!

author: Jwillis
author_rank: Super Contributor
timestamp: March 31, 2020, 05:13:51 am
content: Quote from: stafil on March 28, 2020, 07:02:36 pmThe mosfet is a capacitive load which can cause overshoots, ringing, and even oscillation. By putting a low value resistor in seines with the output . This will isolate the op-amp output and feedback network from the capacitive load . Or If you are concerned about gain accuracy you can use a R-C series snubber circuit from output to ground.

author: Zero999
author_rank: Super Contributor
timestamp: March 31, 2020, 01:12:33 pm
content: Quote from: Jwillis on March 31, 2020, 05:13:51 amYou'll get the same result with a BJT. It's because the transistor increase the voltage gain of the circuit. Adding a resistor in series with the op-amp's inverting input and a capacitor between the inverting-input and the output, forming an integrator, will reduce the high frequency gain of the op-amp and increase the stability.
Converting SFP to USB - Page 1
Forum section: electronics / beginners

author: malwarebuster
author_rank: Newbie
timestamp: February 28, 2023, 01:21:54 am
content: I want to convert serial data from an SFP interface to an isochronous USB stream and vice versa. The signal coming over the SFP is ESCON/SBCON, transmitted at about 200mbps, monodirectional, and with 8/10b encoding. I plan to use an EZ-USB FX2 unit to handle the USB data, and SFP breakout boards are fairly readily available. I wanted to as what I should be using as the intermediary chip to convert the serial data from the SFP to the parallel data stream the EZ-USB expects. I have read about serdes, but these seem to be primarily for higher-speed applications than mine. I think that my signal is too fast for a microcontroller, although I am probably wrong/not looking in the right places. I have also considered using an FPGA, but I don't know what features to look for to meet my needs. I would appreciate any information you can give me on what the best part for this job might be and what to look for when getting it. I am hoping for a solution under $100, but I am open to whatever would work best.Thank you for any information you can provide.

author: m k
author_rank: Super Contributor
timestamp: March 12, 2023, 12:58:14 pm
content: Best part is many times a wrong question, answer is subjective and given variables too many.Maybe now you already have some thoughts how some more precise solution is better than other first but worse after a second thought.Is mono directional equal to half-duplex?If you're tapping SFP you may need two receivers, just like with BaseT connections.Nowadays one can expect that fast hubs are readily available.
converting stereo audio input to mono - Page 1
Forum section: electronics / beginners

author: Adhith
author_rank: Frequent Contributor
timestamp: June 06, 2017, 03:11:26 pm
content: hello everyoneI'm planning to build a mono sub woofer amplifier with TDA 2030A IC as a part of my DIy project. Since the IC is a single channel amplifier, I need to somehow combine the stereo input to mono. Could a two resistor mixer solve the problem??. I dont have any idea to select the values for the resistors. Could anyone suggest me a circuit with the resistor values??

author: JanJansen
author_rank: Frequent Contributor
timestamp: June 06, 2017, 03:12:28 pm
content: I suggest 47K.

author: mariush
author_rank: Super Contributor
timestamp: June 06, 2017, 03:35:10 pm
content: Seehttp://sound.whsites.net/articles/audio-mixing.htm, passive mixing section in particularI'd also suggest tda2050 instead of tda2030 should be just as easy to find as tda2030 and works with wider voltage range (works from lower voltage like 12v making it easy to test the project) but also works with much higher voltage for lots of watts) , so it's easier to work with.

author: darrellg
author_rank: Unknown
timestamp: June 06, 2017, 04:28:02 pm
content: Read this Rane Note, which includes schematics for passive summing circuits:http://www.rane.com/note109.html
Converting USB C adapter from female-to-male?  - Page 1
Forum section: electronics / beginners

author: LooseJunkHater
author_rank: Frequent Contributor
timestamp: August 13, 2023, 03:15:50 pm
content: https://www.aliexpress.com/item/1005004774125212.htmlI had bought a few of these above boards and I like them, but I'd love to convert them to USB-C male instead, so I can plug them directly into power adapters.Can I simply desolder the female plug and solder a male plug on, or are any resistors needed (ex. resistors on CC1/CC2) to do this?

author: ataradov
author_rank: Super Contributor
timestamp: August 13, 2023, 03:54:04 pm
content: It is no different than a permanently attached cable, so it would work You don't need anything extra, but finding a suitable connector may be hard. Male PCB connector is not allowed by the specification. You can only find male connectors that are edge mounted to the PCB designed to be mounted to a tiny thin PCB for cable assemblies.

author: rstofer
author_rank: Super Contributor
timestamp: August 13, 2023, 04:34:47 pm
content: How about a Male by Male adapter?https://www.amazon.com/Duttek-Adapter-Synchronization-Charging-Thunderbolt/dp/B09KY11RQB

author: bitwelder
author_rank: Super Contributor
timestamp: August 14, 2023, 03:06:13 pm
content: I wonder if it wouldn't be a better option to use some very short (10cm?) USB C cables, as the SMT USB C connectors aresometimes not particularly robust and with a stiff connection the plugged assembly might be prone to break by accidentally knocking it.

author: LooseJunkHater
author_rank: Frequent Contributor
timestamp: August 14, 2023, 03:25:44 pm
content: Quote from: bitwelder on August 14, 2023, 03:06:13 pmHonestly I think I'm gonna go this route. USB C cables from AliExpress are ~$3USD each, while it seems like it'll be trial-and-error trying to find some USB C male connectors that have the same/similar pin footprint to the USB C female connectors. Unfortunate but oh well.
Convolution of modulated and carrier signal in MATLAB then plot using plot.ly??? - Page 1
Forum section: electronics / beginners

author: shanecy
author_rank: Contributor
timestamp: May 10, 2014, 07:57:23 pm
content: OVERVIEW:I'm wanting to create a simple sinusoidal signal and a carrier signal then perform a convolution sum displaying the two signals convoluted. Through my reading it speaks of the carrier envelope. I'm not for sure what this means but after I simulate the above using Matlab I need to demodulate the signal to reconstruct the original signal.I'm wanting to use plot.ly to do the plotting located at the linkhttps://plot.ly/plot. Therefore, I need to read in data values into a text file from Matlab so I can upload this file to plot.ly. I have figured this portion out already just playing around in Matlab and ploy.ly.SPECIFICATIONS:Signal Specs I'm wanting to simulateCarrier SignalFreq = 560E3 HzAmp (RMS) = 4.0 VSignal to be ModulatedFreq = 1E3 HzAmp (RMS) = 1.0 V ("Doesn't really matter I'm just choosing 1.0V)Bandwidth = 10E3 Hz ("Interval for AM Broadcast")Modulation Index = 0.8My pseudo code on what I believe I need to do.PART 1 (Doing the Convolution Sum)1.) I need to specify the scale of my time axis2.) Declare the frequency of my two signals3.) Declare the amplitude of my two signals4.) Declare the bandwidth and modulation index5.) Calculate the modulating angular frequencyomega_signal_to_be_modulated = 2*pi*1E36.) Calculate the carrier angular frequencyomega_signal_of_carrier = 2*pi*560E37.) Build the equation for my two sinusoidal signalsy(modulated_signal) = sin(omega_signal_to_be_modulated*time)y(carrier_signal) = sin(omega_signal_of_carrier*time)8.) Calculate the Convolution Sum. I believe this is the correct equation for doing this.Convolution_Sum = Amplitude_of_Carrier_Signal * (1+ modulation_index * y(modulated_signal) ) * y(carrier_signal)9.) Calculate side bands10.) Read all data into a text filePART 2 (Demodulate and Reconstruct the original signal)I need to do the inverse of my convolution sum equation which I believe will separate out the carrier signal and the original signal. I'm unsure on how to write the equation for this.IN CONCLUSIONI am NOT asking for a complete Matlab script. A template, blocks of code explaining on how I should attempt these two scrips or just some good ole advice would be appreciated.Here is the desciption of the software and hardware i'm using for my projectMacBook ProOSX Version 10.9.2MatlabStudent VersionR2013a (8.1.0.604)64-bit(maci64)February 15, 2013I'll be using plot.ly to graph my data in the text file. This program is located at the following link...https://plot.ly/plot

author: Bored@Work
author_rank: Super Contributor
timestamp: May 10, 2014, 08:10:30 pm
content: Quote from: shanecy on May 10, 2014, 07:57:23 pmWhy? Is that some fanboy wanking? Matlab has build-in plotting, use it.

author: shanecy
author_rank: Contributor
timestamp: May 10, 2014, 09:32:40 pm
content: others in my class are using matlab to plot. i easily could as well but i'm just trying to be different and learn something in addition.
Cooking scale - Page 1
Forum section: electronics / beginners

author: Kapton_noKrapton
author_rank: Newbie
timestamp: September 12, 2021, 02:52:09 am
content: Hello, I have a cooking scale that boots but no longer displays the weight, do you have an idea of the problem?

author: amyk
author_rank: Super Contributor
timestamp: September 12, 2021, 03:18:50 am
content: Check the resistance of the strain gauge sensors.

author: james_s
author_rank: Super Contributor
timestamp: September 12, 2021, 03:21:25 am
content: That looks pretty crufty, did it get wet?

author: Kapton_noKrapton
author_rank: Newbie
timestamp: September 12, 2021, 03:35:47 am
content: Yes it's an old scale but it's very effective that's why I wanted to see if it is possible to repair it, on the PCB the resistance is what number? To test it I just take value in ohmmetre? Thank you

author: james_s
author_rank: Super Contributor
timestamp: September 12, 2021, 04:47:25 am
content: Well I was asking if it got wet because that would offer a clue as to where the problem may be, a good start would be cleaning up the board. Nobody can give you an exact resistance value but each of the strain sensors should have roughly the same resistance and the resistance should vary when they are flexed.

author: amyk
author_rank: Super Contributor
timestamp: September 12, 2021, 04:51:08 am
content: Look at the 4 wires coming from the load cell. They are connected to the strain gauges in a bridge configuration. Measure the resistance between them to determine if any of the strain gauges are open or shorted.

author: Kapton_noKrapton
author_rank: Newbie
timestamp: September 12, 2021, 05:26:37 am
content: Yes there is a little oil on it I cleaned with the toothbrush and ISO alcoholOn the PCB, the R41 resistance which is a 684 gives me 40k to the multimeter but I do not know if something wrong the data
Cool stuff to do with cheap modules... #1456 - Page 1
Forum section: electronics / beginners

author: paulca
author_rank: Super Contributor
timestamp: June 14, 2025, 10:28:37 pm
content: Take one of these:https://www.aliexpress.com/item/1005004567063273.html(An 8 way strip of common cathode LEDs on pin headers).Bend the GND (COM) pin out of the way with pliers and it fits perfectly into an Arduino MEGA A0-A7 connector. The COM pin sticking out you can connect to GND. If you accidentally buy common anode, you can just turn everything upside down and connect it to 5V. You will set bits "LOW" for "ON".Then you can do cool assembly language exercises like LED chasers, "knight rider", and bouncing ball.Those ports A0-A7 are all 1 bank of 8 on PORT "K". So you can directly write your whole 8 bit value into PORT K. No need to chop it up into different port banks which you have to for any other set of Arudino pins.I got a few hours of fun out of it anyway. Thought I'd share.The fun is in writing it yourself, but here is starter hint:Code:.equ DDRK, 0x107.equ PORTK, 0x108asm_light_leds:ldi r16, 0xFFsts DDRK, r16 ; Set all 8 as outputldi r16, 0x55 ; alternating pattern Asts PORTK, r16 ; display patternretYou can wire it back to C using:.global asm_light_ledsat the top of the ASM file (.s) and an extern to load it in.extern "C" void asm_light_leds();Exercises:Counter.Single LED shift one direcitonSingle LED shift "ping pong"Bouncing ball (slows at top, accelerates at the bounce)PWM BreatherCombined PWM with LED shifters.Combined PWM shifters with "echo" or "trail".

author: ahsrabrifat
author_rank: Regular Contributor
timestamp: June 17, 2025, 11:56:36 am
content: Thanks for the ideas. In my previous workplace, they made these types of LED boards. These save a lot of type making the connections simple.

author: Infraviolet
author_rank: Super Contributor
timestamp: June 17, 2025, 07:12:46 pm
content: Sounds like the same principle could work on a 328p based Uno too, with PORTD and "digital pins 0-7" instead. Perhaps a good teaching aid for bitwise manipulation actually.
Coplanar Stripline Filter - Page 1
Forum section: electronics / beginners

author: RFbeginner
author_rank: Newbie
timestamp: June 02, 2019, 03:11:58 pm
content: hello everyone,i'm designing (or at least trying to ) a coplanar stripline filter, any filter really but online there isn't a lot of informations about that , all the papers i read do not mention how and the formulas used to design the filters, I wrote a matlab code to determine the slot and strip width (using the formula from every book) and i got 0.769mm for the strip width W and and 0.119mm for Slot width S, which is perfectly confrom to 50Ohm per strip (coupled 100) when i simulated that on CST, I tried various filters i saw online and played with the variablesbut the best I got was some losses but nothing that makes a filter, does anyone here have an idea or formulas i could use to design a filter of any kind (BP,LP,HP,BS) knowing that I want it to work between 2 and 3 GHz ?I would be really grateful.thanks.

author: Benta
author_rank: Super Contributor
timestamp: June 02, 2019, 05:01:17 pm
content: This might help. Check out chapters 3 and 7:https://userweb.jlab.org/~brads/Manuals/Hardware/ECL_Design_Handbook.pdf

author: schratterulrich
author_rank: Regular Contributor
timestamp: June 02, 2019, 07:39:27 pm
content: I have realized my first microstrip filters with ANSOFT Designer SV. It's a limited but free student version of a RF CAD software.Fortunately it includes a very powerful filter design wizard also in the SV version.You can find the software athttp://www.gunthard-kraus.de/Ansoft%20Designer%20SV/Direct download linkhttp://www.gunthard-kraus.de/Ansoft%20Designer%20SV/English%20Tutorial%20Version/DesignerSV050610.exeSince it's been some time since i used this software, i don't know if it's compatible to windows 10.

author: RFbeginner
author_rank: Newbie
timestamp: June 03, 2019, 07:37:17 am
content: @schratterulrich: thank you ! i'll download it and check it today but it seems that it only does microstrip lines , i'm doing a coplanar stripline CPS ( no ground plane, no vias...) i'll check it more later but thanks a lot.@Benta thank you but those formulas are for microstrips, i'm designing a CPS coplanar stripline and since its not very used there isn't really any informations about it...

author: schratterulrich
author_rank: Regular Contributor
timestamp: June 03, 2019, 09:33:09 am
content: Yes you are right, Ansoft Designer won't support CPS structures.To be honest, I didn't even know that these filter type exists.

author: tggzzz
author_rank: Super Contributor
timestamp: June 03, 2019, 09:50:15 am
content: Whymustit be a stripline filter? What's the unique benefit?
Copper hakko clone tips - Page 1
Forum section: electronics / beginners

author: shobo
author_rank: Regular Contributor
timestamp: January 02, 2018, 11:28:01 pm
content: Are there any advantages of having copper tips on a cheapo soldering iron?i guess that they conduct heat better

author: wraper
author_rank: Unknown
timestamp: January 02, 2018, 11:31:23 pm
content: Unless tips are really really crap, they are copper underneath the plating.

author: shobo
author_rank: Regular Contributor
timestamp: January 02, 2018, 11:39:35 pm
content: Quote from: wraper on January 02, 2018, 11:31:23 pmMine are,tested them with a magnet

author: ataradov
author_rank: Super Contributor
timestamp: January 03, 2018, 12:00:45 am
content: I have a set of copper tips (not plated), which I've got just to try. And I don't see a substantial difference in performance compared to the regular tips.But they do work, which is frankly, more than I expected from them

author: wraper
author_rank: Unknown
timestamp: January 03, 2018, 12:01:10 am
content: Quote from: shobo on January 02, 2018, 11:39:35 pmAre what, magnetic? Tinned surface must be magnetic because it is made from iron, the rest of it may be magnetic as well as it may have a bit of iron layer as well. This is how good quality tip is made:

author: shobo
author_rank: Regular Contributor
timestamp: January 03, 2018, 12:05:13 am
content: Quote from: wraper on January 03, 2018, 12:01:10 am

author: wraper
author_rank: Unknown
timestamp: January 03, 2018, 12:09:54 am
content: https://www.hakkousa.com/lead-free/Genuine hakko:

author: shobo
author_rank: Regular Contributor
timestamp: January 04, 2018, 10:38:32 am
content: Quote from: wraper on January 03, 2018, 12:09:54 amthe magned is pretty well attracted to it as if they are solid steel/ironSent from my SHV-E250L using Tapatalk

author: mikerj
author_rank: Super Contributor
timestamp: January 04, 2018, 01:31:08 pm
content: Quote from: ataradov on January 03, 2018, 12:00:45 amPure copper works perfectly well IME, they just erode quickly without the protective plating.

author: wraper
author_rank: Unknown
timestamp: January 04, 2018, 01:42:28 pm
content: Quote from: mikerj on January 04, 2018, 01:31:08 pmExposed copper won't last even hour of soldering without significantly eroding. And if you solder lead-free they'll basically dissolve in solder in front of your eyes.
Copper Magnet Wire Breakdown Voltage - Page 1
Forum section: electronics / beginners

author: ZeroResistance
author_rank: Frequent Contributor
timestamp: September 21, 2018, 08:24:55 am
content: I intend to use round enamelled copper wire for voltages upto 500V.I see that as perhttps://en.wikipedia.org/wiki/Magnet_wire.QuoteIn the 500V application that I have is of a capacitor discharge magnetizer, the magnet wire would be subjected to current pulses not more than 10A. Capacitor would be charged to upto 500V.My questions are do I really need to used Grade III wire for this application.what kind of enamel coating is suitable for this voltage range, I see that threre are a range of single and dual coat insulation coatings for magnet wire. Polyester, Polyesteramide, Polyamide-Imide.Is thare an insualtion coating well suited for this voltage range.There is also thermal class. But currently I'am more concerned for the voltage breakdown rating of the wire.Thanks in Advance.

author: IanB
author_rank: Super Contributor
timestamp: September 21, 2018, 09:38:31 am
content: You care about the voltage difference between the wire and anything it is touching. Commonly this would be adjacent turns in a coil, so that voltage per turn becomes important.A higher voltage could exist between one layer of a coil and the next outer/inner layer. This can be mitigated by including a wrap of insulation between each layer on the coil former.Given these considerations, the source voltage of 500 V is almost irrelevant. You need to consider the worst case insulation stress based on the design of your system and where maximum voltage differences will appear.

author: ZeroResistance
author_rank: Frequent Contributor
timestamp: September 21, 2018, 12:20:02 pm
content: Quote from: IanB on September 21, 2018, 09:38:31 amI am actually trying to avoid putting in the extra insulation and for this going in for either Grade II or Grade III magnet wire which has a thicker insulation than Grade I.I have found a table of insulation thicknesses for various grades and various AWG / SWG sizes of conductors. However to add to this I need a method to calculate the breakdown voltage for a particular conductor dia and particular enamel thickness, maybe enamel material also comes into play here.That would enable me to select either Grade I , II or III.

author: tpowell1830
author_rank: Frequent Contributor
timestamp: September 21, 2018, 12:31:38 pm
content: I see you are focusing on the wire, although the only determining factor is the actual coating breakdown voltage parameters. Any insulating materials have a breakdown voltage rating and this is also determined per thickness (i.e. per mm). You would then have to know how many mm the coating is and then determine whether it suits your needs. For instance PTFE breakdown voltage is 19.7 KV/mm. This is also know as the dielectric strength. Magnet wire is coated with different types of material and this is your determining factor.Hope this helps...
Copper pours and QFN chips - Page 1
Forum section: electronics / beginners

author: gautam023
author_rank: Newbie
timestamp: June 10, 2021, 01:50:30 pm
content: Hello everyone,I am a newbie to PCB design. I have a QFN chip, a power converter IC (LT3958 - datasheethere).Polygon pour is not surrounding the bottom pins unless I remove thermals from it. Is it recommended to remove thermals in this case? I have attached screenshots with and without thermals.Thank you in advance for any help.PS: I am using Eagle software.

author: Galaxyrise
author_rank: Frequent Contributor
timestamp: June 12, 2021, 02:00:04 pm
content: the datasheet wants low impedance loops, so you shouldn’t have skinny thermal relief. thermals are to make localized soldering easier, but you already have large pads you can’t reach with an iron. If you’re doing stencil + reflow, then you don’t need thermals. If using hot air, plan to solder that entire loop at the same time.The data sheet uses a solid fill, too, and I don’t think I would stray from their recommendation in that respect either

author: JustMeHere
author_rank: Frequent Contributor
timestamp: June 12, 2021, 05:55:32 pm
content: Agree with the post above. Follow the datasheetGet rid of those holes in the pour. You will have problems with them anyway. The solder will likely bridge over them, so you're not getting any benefit. It just makes less contact space for your pad to contact and transfer heat.

author: Unixon
author_rank: Frequent Contributor
timestamp: June 12, 2021, 06:40:48 pm
content: Leave thermals on original polygon, you're probably need them for other parts.Add another polygon with solid fill and without thermals on top of the first polygon just for a small area under and near IC (cover thermals + polygon wire width).

author: gautam023
author_rank: Newbie
timestamp: June 15, 2021, 07:37:12 am
content: Thank you for the help everyone.Using another polygon for just under the IC with thermals off and Isolate of 6 does the job. Now the copper pour is surrounding the pads.
Copper trace thickness/width calculation? - Page 1
Forum section: electronics / beginners

author: The Magic Rabbit
author_rank: Regular Contributor
timestamp: September 19, 2015, 09:28:35 pm
content: I'm making my first copper board. Is there a formula to calculate how thick I should make a track based on the power? Most of it is either 5V or 12V at less than 10mA but there are a few tracks that will be carrying 12V at up to 2A, from the FETs.Sent from my XT1039 using Tapatalk

author: Farley
author_rank: Regular Contributor
timestamp: September 19, 2015, 09:53:47 pm
content: Try this site:http://www.4pcb.com/trace-width-calculator.htmlIt has javascript calculators and also shows the formulas used if you scroll down a bit.

author: The Magic Rabbit
author_rank: Regular Contributor
timestamp: September 20, 2015, 03:04:54 pm
content: Thanks!Sent from my XT1039 using Tapatalk

author: waspinator
author_rank: Contributor
timestamp: April 08, 2016, 06:51:33 pm
content: Quote from: Farley on September 19, 2015, 09:53:47 pmWhy does only current matter in the calculations? if I have 30V at 1A it suggest a 30mil trace, or 1V at 30A, isn't the same amount of power dissipated?

author: johansen
author_rank: Super Contributor
timestamp: April 08, 2016, 06:54:19 pm
content: Quote from: waspinator on April 08, 2016, 06:51:33 pmpower loss is resistance times amps squared.

author: Kilrah
author_rank: Unknown
timestamp: April 08, 2016, 06:55:13 pm
content: P=RI^2.R depends on your trace, all that's left is current.Voltage plays no role in the heating part of it.

author: Neilm
author_rank: Super Contributor
timestamp: April 08, 2016, 07:16:01 pm
content: Quote from: waspinator on April 08, 2016, 06:51:33 pmThe track is carrying the same amount of power - it is not dissipating that power. The power that is dissipated is the small voltage drop you will have along that trace. Making the trace wider will reduce the resistance of the trace and hence reduce the voltage drop.

author: fubar.gr
author_rank: Unknown
timestamp: April 09, 2016, 09:51:37 am
content: Another very good PCB calculator is Saturn PCB Toolkit:http://www.saturnpcb.com/pcb_toolkit.htmWhen specifying trace width you have to take into account1) what is the max desired temp rise above ambient and2) what is the max voltage drop you can tolerateSometimes the only way to fullfil the above requirements within a specific PCB area will be to either use a heavier copper PCB or add more solder and/or external copper wire.
Copper Wire Disappearing - Page 1
Forum section: electronics / beginners

author: bobcat2000
author_rank: Regular Contributor
timestamp: May 31, 2021, 02:03:26 am
content: Hello,I am shopping for a new roll of 24 AWG and 28 AWG copper wire. The electronic stores near my place all went under. So, Amazon it is. To be my surprise, Amazon does not list 28 AWG copper wire anymore. Do you know the reason 28 AWG disappears?Thanks!

author: bob91343
author_rank: Super Contributor
timestamp: May 31, 2021, 03:40:22 am
content: https://www.mouser.com/Wire-Cable/Hook-up-Wire/_/N-5ggs?P=1yx5jlyZ1y8trjmZ1y7mohoZ1z0xfpoI don't buy from Amazon. Prices always too high.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: May 31, 2021, 03:56:35 am
content: I am sure it is just another manifestation of the supply chain disruptions that are occurring because of trade wars and COVID. Why would you make 28 gauge wire when the demand for 12 and 14 gauge is through the roof and commanding outrageous prices, just like almost every other building material.

author: bobcat2000
author_rank: Regular Contributor
timestamp: May 31, 2021, 04:30:11 am
content: Oh. I don't need that much. Just one of these boxes with 6 colors.Amazon does sell 28 AWG wires. Amazon does not list it there to the left.https://www.amazon.com/StrivedayTM-Flexible-Silicone-electronic-electrics/dp/B01KQ2LHFI/ref=cr_br_sbs_1/135-5639377-0932440?pd_rd_w=wp09k&pf_rd_p=64f61ea4-75af-4b1f-924f-e0e4e629d2cc&pf_rd_r=Z9W2SHYD3TM86KS2NNWQ&pd_rd_r=89b5345d-978a-4836-9fad-78b5f7f71de7&pd_rd_wg=wuKOu&pd_rd_i=B01KQ2JNLI&th=1

author: bobcat2000
author_rank: Regular Contributor
timestamp: May 31, 2021, 04:33:58 am
content: Ah! I see why Amazon does not list 28 AWG wire in the page. Amazon only shows the items the "featured" brands are selling. None of the "featured" brands sells any 28 AWG wire. That's why 28 AWG is not listed.

author: Jwillis
author_rank: Super Contributor
timestamp: May 31, 2021, 05:41:29 am
content: Your in the States go here ..remingtonindustriesPrices and shipping aren't bad.

author: bobcat2000
author_rank: Regular Contributor
timestamp: May 31, 2021, 04:21:20 pm
content: Thanks! Look great. We need more stores like this.

author: Ground_Loop
author_rank: Frequent Contributor
timestamp: June 02, 2021, 04:09:17 am
content: Try Skycraft Surplus in Winter Park, FL.

author: james_s
author_rank: Super Contributor
timestamp: June 02, 2021, 07:04:08 am
content: Amazon is useless for stuff like this, I don't know why so many people buy electronic components and such from them. All Electronics, Marlin P. Jones, and several other smaller operations like that are much better choices. Try Amazon if you need something for your kitchen or bathroom.

author: radiolistener
author_rank: Super Contributor
timestamp: June 02, 2021, 03:10:46 pm
content: It appears that copper is a very precious and scarce material, so we needs to use Chinese rotten silumin wires instead
Correct fuse replacement - Page 1
Forum section: electronics / beginners

author: HansMan
author_rank: Newbie
timestamp: October 24, 2018, 08:37:15 am
content: Hello EEVblog Electronics Community Forum!I have problem finding correct replacement fuse because i haven`t encountered that kind of fuse before.I believe this is HRC Fuse ? How to choose replacement? There is no amperage rating, only power and resistance. This is SMPS , 220v ac to 12v dc, 2A output.

author: capt bullshot
author_rank: Super Contributor
timestamp: October 24, 2018, 09:07:04 am
content: That's an wirewound resistor, not a fuse.Maybe it has some kind of fusible rating.An arbitrary example (not checked if it is a proper replacement for your resistor):https://www.mouser.de/datasheet/2/427/acxxcs-1103032.pdf

author: Whales
author_rank: Super Contributor
timestamp: October 24, 2018, 09:56:03 am
content: 5 ohm 2W ceramic wire-wound resistor. Not a fuse.You don't want a fuse with this much thermal mass, your wires would burn before the fuse would.

author: sleemanj
author_rank: Super Contributor
timestamp: October 24, 2018, 12:31:12 pm
content: fusible resistor, yes they are made in this style, primarily for fusing against a direct short across mains I think, while not fusing for transient high voltages. The fusing characteristic would be determined by the power rating I expect, but I'm not familiar. Compare a non-fusible of the same specs could be significantly overloaded and get hot enough to ignite things (you can easily overload a 5w wire wound resistor to such a point that the wire is visible glowing red hot). In other words, fusible resistors are supposed to fail in a safe manner, standard ones however may fail in undesirable ways.

author: Neilm
author_rank: Super Contributor
timestamp: October 24, 2018, 06:46:47 pm
content: That is a fusible resistor. They can be a bit hard to find - generally they are used as anti-surge devices in power supplies. I have used one to limit the charging of the supply caps. It was rated to allow the capacitors to charge, but blow if the caps took to much charge (for instance if the voltage didn't rise correctly)

author: ArthurDent
author_rank: Super Contributor
timestamp: October 25, 2018, 01:58:27 am
content: I'm not sure where you'd have to look in your area but in the U.S. on eBay they can be found. Some have leads like this one which should still work in your circuit. Reading the listing may also help to give you some info.https://www.ebay.com/itm/1X-5J2R0-2-ohm-5-watt-cement-fusible-resistor-will-replace-RGDU5M-5E-1-8-OHM-/142032672375

author: Whales
author_rank: Super Contributor
timestamp: October 25, 2018, 07:20:42 am
content: Wow, OKApologies.
Correct Ground Trace - Page 1
Forum section: electronics / beginners

author: mike_mike
author_rank: Super Contributor
timestamp: April 16, 2020, 08:35:55 am
content: Hello, I just found that my layouts does not have correct ground traces, so I want to learn something about designing the ground trace.I took the attached schematic and I want to make the correct ground design.Please have a look at the PCB layout that I draw and tell me what should I improve.

author: tggzzz
author_rank: Super Contributor
timestamp: April 16, 2020, 08:53:05 am
content: Quote from: mike_mike on April 16, 2020, 08:35:55 amWhat makes you think that? In what way do you want to change performance?In generalhaving a solid ground plane is A Good Thing. But without a definition of yourproblem, we can't say what asolutionmight be.

author: RoGeorge
author_rank: Super Contributor
timestamp: April 16, 2020, 09:31:58 am
content: The dedicated therm you are looking for is "ground loops", not ground traces. The name 'ground loops' suggests it should be something about GND, but this isnotabout GND only. It applies in any circuit where two independent current loops have a common path.The common path/trace have a small resistance that is not zero, so the current from one loop will create a voltage drop on that portion of the common circuit, because of that small resistance of the common path (the common path in practice is a portion of a wire or a segment of a PCB trace). The voltage drop created by one current loop will appear as a perturbing voltage source for the other current loop, and this is usually an unwanted effect that must be avoided. For example, a ground loop can make a perfect amplifier to auto-oscilate, and so on.Search about ground loop, why are they bad, and how to avoid them in practice.For a good PCB layout, ground loops should be avoided. This is about ground loops in general, I didn't check the layout of your PCB.

author: Rerouter
author_rank: Super Contributor
timestamp: April 16, 2020, 09:34:31 am
content: A starting fix would be the large input capacitor, general rule of thumb is to have your loads connected to the capacitor, and then from the capacitor to the supply rails (decoupling)same for your switch, have it connect to its decoupling capacitor then the power input plug.This kind of circuit really should not need a star ground, and would also agree that a solid plane would meet most roles (Ironically I am working on a similar circuit where start grounding matters, but that is with a 6.5 digit ADC)

author: tggzzz
author_rank: Super Contributor
timestamp: April 16, 2020, 10:44:19 am
content: Quote from: RoGeorge on April 16, 2020, 09:31:58 amThere is insufficient information in the OP's post to draw that conclusion - which may or may not be the case.

author: RoGeorge
author_rank: Super Contributor
timestamp: April 16, 2020, 11:15:29 am
content: Indeed. It just happened that I already knew the project where from this question is derived, and just wanted to clarify the name for the OP:https://www.eevblog.com/forum/beginners/arduino-pid-soldering-station/
Correct Impedance settings/circuit for Scope, Function Generator, and ADC setup - Page 1
Forum section: electronics / beginners

author: nummy
author_rank: Newbie
timestamp: April 07, 2014, 01:22:02 pm
content: I have an Agilent (33220A) Function Generator set up to output a simple 60Hz sine wave. I'm feeding this to an ADC pin on a microprocessor (TMS320F28069). The output impedance is set to "High Z". I also have a scope set to measure the signal being applied on the ADC pin. The scope has an imput impedance setting of 1Mohm (you can choose 50ohm or 1Mohm).According to the microprocessor documentation, this is how the ADC is setup internally.Up until now, I have just been connecting the output of the function generatordirectlyto the ADC pin. Am I doing this wrong?Should I be connecting the function generator to the ADC pin with a 50ohm resistor in series? Should I have a capacitor somewhere?Should I then change my setting on the function generator to 50ohm output impedance? And then changing my scope to 50ohm input impedance?

author: Marco
author_rank: Super Contributor
timestamp: April 07, 2014, 01:48:20 pm
content: Quote from: nummy on April 07, 2014, 01:22:02 pmNo, it isn't ... the expected load impedance is set to High Z. The generator uses this to estimate what voltage the load will see (ie. it assumes it will see the full output voltage because the fixed 50 Ohm output resistance of the generator will take nearly no voltage). You should only use this at low frequencies or when using short cables. In this case (at 60 Hz with 1K input impedance for your ADC) it's fine.QuoteThis is fine.QuoteNo, in this case it's fine ... the input impedance of your ADC is 1K Ohm and you're using low frequencies so it's relatively accurate. Just be aware that your ADC only sees 1000:1050 of the voltage you're setting on your generator.QuoteNo ... you could use a 50 Ohm parallel termination at higher frequencies though, you could put your scope on 50 Ohm input if you put a splitter straight on it's BNC input with a very short cable to the ADC, that way you use the scopes internal 50 Ohm termination (not valid at very high frequencies, but with the generator only doing 20 MHz it's okay).All that said, you should really read up on termination ... because all I said is probably voodoo to you without the necessary context.

author: BravoV
author_rank: Super Contributor
timestamp: April 07, 2014, 02:07:19 pm
content: Maybe this will help ?

author: w2aew
author_rank: Super Contributor
timestamp: April 07, 2014, 02:34:11 pm
content: Quote from: nummy on April 07, 2014, 01:22:02 pmImportant note - the generator *always* has a 50 ohm resistor in series with the output! Changing the *load* impedance setting on the generator only changes the way the generator calculates the voltage to be generated, it does NOT change the output impedance of the generator.

author: nummy
author_rank: Newbie
timestamp: April 07, 2014, 03:12:47 pm
content: Great tips, thanks guys!
Correct method to trigger on mains AC signal - Page 1
Forum section: electronics / beginners

author: canvas
author_rank: Newbie
timestamp: November 14, 2024, 08:52:57 am
content: I am about to measure the interrupt time of an off-line UPS on power lost. I will measure its output mains voltage with my oscilloscope. I will be making the measurement through HV differential probe, so the polarity isn't a problem. I am expecting the AC sine wave will gradually deminish to 0V and later, the inverter will switch on. How can I trigger such event on an oscilloscope? Thanks.

author: Andy Chee
author_rank: Super Contributor
timestamp: November 14, 2024, 08:56:29 am
content: What is your oscilloscope model?

author: ejeffrey
author_rank: Super Contributor
timestamp: November 14, 2024, 09:25:32 am
content: You could trigger on the UPS startup then look at the pre trigger data. One way would be to measure the current on the battery cable.
Correct punchdown tool for this connector? - Page 1
Forum section: electronics / beginners

author: Cozzmo
author_rank: Regular Contributor
timestamp: September 26, 2017, 06:19:39 am
content: I have a bunch of these connectors that i'm making some cables with, i have been using a screw driver to punchdown the wires but its not 'right'. Does anyone know what the connector is called and the correct tool for punching down the wires ?

author: radar_macgyver
author_rank: Frequent Contributor
timestamp: September 26, 2017, 06:29:43 am
content: These look like MTA-100 or MTA-156 (pitch of 0.1 or 0.156"), please see my response to a similar question below:https://www.eevblog.com/forum/reviews/panduit-(or-similar)-insulation-displacement-connector-tool-(gun)/msg1175152/#msg1175152

author: Nusa
author_rank: Super Contributor
timestamp: September 26, 2017, 06:56:05 am
content: Yes, those look like MTA connectors of some brand, for which manual punch tools exist.For good results, you need to use thestrandedwire size the connector was designed for.

author: Cozzmo
author_rank: Regular Contributor
timestamp: September 26, 2017, 09:20:58 am
content: Thanks guys, excellent info set me in the right direction.
Correct voltage translator - Page 1
Forum section: electronics / beginners

author: Vindhyachal.takniki
author_rank: Frequent Contributor
timestamp: May 12, 2015, 08:58:51 am
content: 1. I have a motor encode with max speed = 6000 rpm & 3600 pulses at each revolution.So max freq = 6000*3600 = 21.6Mhz.2. Encode is powered by 10-30V dc. But MCU is powered by 3.3V.3. So I need to step down the voltage of encoder pulses.4. Currently encoder is powered by 10V. I have a placed a small resistor & 3.6V zener. I am getting step down voltage but there is some rise & fall of pulse at across zener, which I see is comparable when I compare encoder output & zener out.5. I can use either optocoupler or any buffer IC for this.6. I had looked at FOD8001, 25Mhz, but it require Vcc at input also. and max is 3.3 or 5V only.ICPL2631 is 10Mhz.7. Avago HCPL-0720, is good, but it require VCC at input with max of 6V. I need to place some regulator for powering input vdd also.8. Any other product fit for this?

author: bktemp
author_rank: Super Contributor
timestamp: May 12, 2015, 09:16:03 am
content: Quote from: Vindhyachal.takniki on May 12, 2015, 08:58:51 amrpm = per minute, so you only have 360kHz not 21.6MHz.

author: Vindhyachal.takniki
author_rank: Frequent Contributor
timestamp: May 12, 2015, 09:59:41 am
content: Sry its 360khz

author: Rerouter
author_rank: Super Contributor
timestamp: May 12, 2015, 10:08:39 am
content: Here you go, a cut back version of the input on a frequency counter project of mine, it ensures you get an accurate representation of the rising and falling edges even when the circuit does not get close to ground,
Correct way for mechanical sprung electrical conenction? (Pogo Pins) - Page 1
Forum section: electronics / beginners

author: Shinkaze
author_rank: Newbie
timestamp: January 04, 2021, 08:10:58 pm
content: Hi All,First post.I have a potential solution for an electrical connection, but am concerned that I am asking more than a Pogo Pin is designed to do.Desired result (without outer steel shell)My Question :What is the appropriatemechanical Connectionwith a ~1.5mm sliding metal sleeve?Scenario: I need to connect a pair of switches from a Graflex Clamp into a chassis separated by a steel tube. I can drill a hole into the tube so that the pogopin can extend down into the chassis, HOWEVER, the tube needs to be removable so it will need to Sheer past the pogo pins.The case needs to be able to slide in and "twist" to lock.I will cut a window for the pogopins to pop into when the case is in the proper twisted position.PogoPin connection:Example Connector:Concern: Can the Pogopins handle thesheer stressof the steel tube passes between the pin and gate?Question: What is the appropriate way to make this connection?Any help deeply appreciated!

author: thm_w
author_rank: Super Contributor
timestamp: January 04, 2021, 10:56:53 pm
content: The appropriate way is with a magnet, screw, or other method that allows the pins to move vertically in line with the spring.https://www.google.com/search?q=pogo+pin+charger&source=lnms&tbm=isch&sa=XShould still be possible to achieve that with your design.

author: tooki
author_rank: Super Contributor
timestamp: January 04, 2021, 11:12:14 pm
content: Take a look at some SLR/mirrorless camera bayonet mounts to see how they solve it. (Canon EOS, Nikon F and Z, Sony Alpha, etc) In particular, take a look at Nikon F, since that mount was originally completely mechanical, and only had electrical contacts added years later, so they're in a different orientation than all the others.

author: Shinkaze
author_rank: Newbie
timestamp: January 05, 2021, 02:51:14 am
content: Quote from: tooki on January 04, 2021, 11:12:14 pmThan you, yes, it appears there is a ballhead pogo pin design is designed for lateral stability.Further research has yielded a potential pin with a 1.4mm stroke that *might* be enough to clear the casing.I guess my next Electronics quest is to learn how to order and test custom ballhead pins .....

author: Shinkaze
author_rank: Newbie
timestamp: January 05, 2021, 02:56:18 am
content: Quote from: thm_w on January 04, 2021, 10:56:53 pmAgreed, The proper way is some sort of chassis that lifts the pins, and when the chassis pops down it brings the pins with it. Magnets might be a way to pull the pins into lock,.....if the ballhead pogo pin doesn't pan then I might have to rethink how to make a kinematic connector with springs/magnets......which is a lot more scope.