hybridfree/eevblog-posts huggingface dataset:
Ceramic Loop antenna front end-Match tuning-Filtering - Page 1
Forum section: electronics / projects

author: electronx
author_rank: Regular Contributor
timestamp: December 02, 2024, 10:38:44 am
content: I came across such a schematic. I can understand the match tuning CL structure just before the antenna. However, the previous pi structure confused me. What does this pi filter do, why a cascaded system?

author: ftg
author_rank: Frequent Contributor
timestamp: December 02, 2024, 10:42:07 am
content: The C5-L1-C6 Pi-pad could be for matching the RF output pin to 50ohms, so that the filter sees proper 50ohms and preforms as it is supposed to.

author: SeanB
author_rank: Super Contributor
timestamp: December 02, 2024, 12:50:45 pm
content: Filters are there because the SAW filter will have responses at harmonics of the input, so the input side filter is there to reduce them to a level where the output, again after filtering, will not exceed allowed spurious emission levels. that 2.85GHz output from the IC is going to not be a perfect sine wave, it will probably have a lot of harmonics not filtered on the chip, so you need the filter to attenuate them, and also to reduce any RF reflections back to the output stage of the IC as well, to allow for highest power output, along with limiting the out of band energy when it is switched to receive the signal from other endpoints. filter each side to reduce harmonic energy that say comes from a 5GHz AP or device close by, that would otherwise saturate the receiver signal wise.

author: ftg
author_rank: Frequent Contributor
timestamp: December 02, 2024, 12:59:42 pm
content: The LFL182G45TC1A108 seems to be an LTCC low pass filter with 50ohm port impedances.No idea what the RF IC is, so cannot really comment on it's RF port's output impedance, but it often ain't 50ohms in most cheap stuff.Annoyingly muRata does not seem to have any data for the expected attenuation.Outside of these two lines:27.0 dB min. at 4800.00~5000.00 MHz25.0 dB min. at 7200.00~7500.00 MHzWhich naturally only apply if both ports are 50ohms.https://www.murata.com/en-us/products/productdetail?partno=LFL182G45TC1A108
Ceramic resonator or crystal ??? - Page 1
Forum section: electronics / projects

author: danielks
author_rank: Contributor
timestamp: August 02, 2011, 04:51:00 pm
content: Can anyone suggest to me which one is better ? Ceramic resonator or crystal ? Which is more accurate and which is less sensitive to vibrations.

author: Conrad Hoffman
author_rank: Super Contributor
timestamp: August 02, 2011, 05:21:41 pm
content: I think either is rugged, but the crystal will be more accurate. Ceramic resonators are generally used as a cheaper alternative to expensive crystals. The Q of a crystal will also generally be higher.

author: Unknown
author_rank: Unknown
timestamp: August 02, 2011, 10:38:52 pm
content: Ceramic resonators are usually a cheap, inferior alternative. One advantage is that their start-up time is faster.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: August 02, 2011, 10:58:58 pm
content: Ceramic resonators are adequate for all but the most accurate timing requirements - typically 0.5% or so - fine for async comms but not USB or timekeeping.Resonators are available as 3-terminal devices with built-in caps to reduce component count. Unless you actually need the accuracy, ceramic resonators are generally the cheaper and smaller choice.

author: Unknown
author_rank: Unknown
timestamp: August 02, 2011, 11:06:05 pm
content: danielks,more factors should be considered when selecting oscillator components even for basic projects. For example, ceramic resonator might not work at all if sufficient drive level cant be provided.An overview with good tips can be found here:http://ww1.microchip.com/downloads/en/devicedoc/osilator.pdfwith a more detailed discussion here:http://ww1.microchip.com/downloads/en/AppNotes/00826a.pdfReading these two will answer your question and more.
Certificates needed when selling electronic kits - Page 1
Forum section: electronics / projects

author: mrburnzie
author_rank: Regular Contributor
timestamp: April 12, 2020, 06:33:29 pm
content: What kind of papers/certifications do I need to be able to sell electronic kits online?If yes, what kind of and what kind of price range am I looking at?

author: coromonadalix
author_rank: Super Contributor
timestamp: April 13, 2020, 08:40:41 pm
content: read this threadhttps://www.eevblog.com/forum/projects/bring-a-product-to-market-without-certification/msg2948876/#msg2948876
Certification requirements for product containing lithium batteries - Page 1
Forum section: electronics / projects

author: matt111
author_rank: Newbie
timestamp: June 08, 2016, 04:57:01 pm
content: I am designing an embedded product that contains rechargeable lithium Polymer battery packs. The product will have an on board battery charger which will take a DC input from an off the shelf wall wart.The product will not be sold to any third party; it will only be used by employees to perform a service in Canada and the US.I have a number of questions regarding required certifications:-From what I have read UN38.3 addresses the certification/tests required to transport lithium batteries by air but does not apply to products containing lithium batteries. If I took UN38.3 certified batteries and used them in a product, does the product need to be certified to some equivalent standard similar to UN38.3 in order to be shipped by air? If so, where can I find information regarding this certification?-Is there any certifications required (from a safety perspective) for products that contain on board lithium battery chargers?I’m trying to determine what our company needs to do from a legal/safety perspective to ensure our design meets any certifications or standards needed.
Certifications on Li-ion powered devices - Page 1
Forum section: electronics / projects

author: blueskull
author_rank: Unknown
timestamp: April 14, 2018, 04:23:12 am
content: As the title suggests, is there any mandatory certification requirements for me if I want to sell a product that contains a (actually 3) Li-ion battery?I know some big brand power banks (Xiaomi, Huawei) have CE logo with comment "certified based on self declaration", so I would assume I can get around with a non-accredited third party lab test report for selling to EU.Is there any requirements for selling to US and China?My product is NOT a general purpose power bank. It's a power unit specifically designed for another product and is only usable with that other product.My product is a finished product, not just a battery pack.FYI, cells I use are already UL1642 and UN38.3 listed, made by Sony. The cells are not protected, but I have attached protection boards right next to batteries.The total capacity is less than 99Wh (in this case, 37.6Wh), so IATA should not give me any troubles.Any suggestions?
CES Meet Up? - Page 1
Forum section: electronics / projects

author: calexanian
author_rank: Super Contributor
timestamp: December 12, 2013, 12:18:13 am
content: As I am making my CES plans I am wondering, how many EEVblog and TheAmpHour listeners and forum members will be walking the aisles along with me. A meet up may be in order at some point. Any thoughts?

author: EEVblog
author_rank: Unknown
timestamp: December 12, 2013, 12:20:16 am
content: The T-Shirts are usually a dead giveaway!Ran into more than a dozen EEVblog shirts at the recent maker faire.

author: calexanian
author_rank: Super Contributor
timestamp: December 12, 2013, 12:38:55 am
content: We should have a contest who can get the most free components our of the Asian vendors in the north LVH hall! I feel so sorry for many of them.

author: ben_r_
author_rank: Frequent Contributor
timestamp: December 12, 2013, 06:54:28 pm
content: Ill be there. This will be my third year in a row.

author: SeanB
author_rank: Super Contributor
timestamp: December 13, 2013, 05:30:22 pm
content: I just want to get a kilo or so of assorted SMD small parts, and then will make a small series of modern arts out of them.

author: calexanian
author_rank: Super Contributor
timestamp: December 13, 2013, 05:33:00 pm
content: That sounds like fun!

author: ben_r_
author_rank: Frequent Contributor
timestamp: December 13, 2013, 06:27:57 pm
content: Dave youre not by chance going to be attending CES this year are you?

author: krux
author_rank: Unknown
timestamp: December 13, 2013, 10:18:19 pm
content: Quote from: calexanian on December 12, 2013, 12:18:13 amCool. While you are in town, you should check out the local hackerspace, SYN Shop.

author: calexanian
author_rank: Super Contributor
timestamp: December 13, 2013, 10:30:55 pm
content: Sweet! I will plan on dropping by!

author: sjg0
author_rank: Newbie
timestamp: December 23, 2013, 09:11:30 pm
content: Are there any other events going on besides CES that you guys will be attending or know of? I will be going with a few friends/colleagues and was just trying to scout some activities besides the casinos.

author: calexanian
author_rank: Super Contributor
timestamp: December 23, 2013, 10:23:30 pm
content: I find the show itself takes up as much time as I can throw at it! However in the evening its just the typical Vegas thing. I may go see Penn and Teller again... I really want to see the 3D printing demo area. I am driving this year and would totally not be upset to bring home a unit somebody did not want to pay to have shipped home!

author: true
author_rank: Frequent Contributor
timestamp: December 24, 2013, 03:21:53 am
content: I'll surely be working, fixing something in one of the casinos or the like while you all enjoy your time at CES
CES Recap - Page 1
Forum section: electronics / projects

author: calexanian
author_rank: Super Contributor
timestamp: January 12, 2014, 06:04:14 am
content: Just got back from CES. Nothing but an ocean of junk. As always a race to the bottom price and quality. It basically will eject out of the mold, down a chute, and right into the landfill.

author: mrflibble
author_rank: Super Contributor
timestamp: January 12, 2014, 06:27:22 am
content: Quote from: calexanian on January 12, 2014, 06:04:14 amIt's Not Just Good, It's Good Enough!

author: Skimask
author_rank: Super Contributor
timestamp: January 12, 2014, 08:09:09 am
content: http://www.startupvitamins.com/products/startup-poster-fuck-it-ship-it

author: calexanian
author_rank: Super Contributor
timestamp: January 12, 2014, 06:18:54 pm
content: Quote from: Skimask on January 12, 2014, 08:09:09 am$26 for that? I can print that on our schematic printer for like $2!!
CF Card corruption on power loss - Page 1
Forum section: electronics / projects

author: nockieboy
author_rank: Super Contributor
timestamp: February 16, 2018, 11:17:52 am
content: Hi,I have a DIY single-board computer (extensively discussed elsewhere in this forum) which runs CP/M from a CompactFlash card connected via an 8-bit IDE interface.All works fine with the original 64MB CF card and a newer one I have for testing. I also have a 128MB CF card that I'm using to test a BIOS that provides CP/M with more drives.Everything works fine and dandy with the 128MB CF card, until I turn the SBC off (or, more accurately, pull the USB serial connection from the PC.) When I next power up the computer, it won't load CP/M and I have to re-install (write CP/M and BIOS to sector 0 of the CF card).A check of the code in memory shows that the last two pages (FE00-FFFF) are corrupt. The monitor ROM loads Sector 0 from CE00-FFFF, and it seems the last part of Sector 0 is getting corrupted every time the SBC loses power. This is 100% reproducible every time with the 128MB CF card (the others are fine, by the way.)So, I guess what I'm asking is this: what failure mode would cause this behaviour in the CF card?

author: David Hess
author_rank: Super Contributor
timestamp: February 16, 2018, 06:54:05 pm
content: Is there a reset or active pin on the IDE interface? If it is being held in the wrong state when power is lost, then I could see the Compact Flash card interpreting the corrupted bus signals as a write command.Usually the thing to do is implement a power loss signal which asynchronously activates all of the various reset signals before power is lost.

author: nockieboy
author_rank: Super Contributor
timestamp: February 16, 2018, 09:37:12 pm
content: Hmm, well the CF interface is wired identically to this schematic below:The reset circuit differs in that I have an MMU reset connected to it as well, but I'm not convinced it's a hardware design issue at the moment as I have two other CF cards that work absolutely fine with the existing setup. I'm wondering if the CF card has a fault - is there any way I can test it for integrity?
cfl lamp induction heater - Page 1
Forum section: electronics / projects

author: coppercone2
author_rank: Super Contributor
timestamp: April 07, 2024, 11:12:19 am
content: It appears this guy got rid of the middle man, aka everythingIf its real, macguyver 10/10

author: Gyro
author_rank: Super Contributor
timestamp: April 07, 2024, 12:55:45 pm
content: Let's skip the primary - secondary insulation shall we?

author: Ian.M
author_rank: Super Contributor
timestamp: April 07, 2024, 01:04:58 pm
content: Also, a 6mm ID work coil (5:43) is pretty ****ing useless.

author: robert.rozee
author_rank: Frequent Contributor
timestamp: April 07, 2024, 02:59:26 pm
content: there seem to be a great many youtube videos showing people how to do things that are dangerous and may result in their serious injury or death. for some reason youtube chooses to turn a blind eye to this, whereas they come down hard if someone uses a piece of background music thatmaybe copyrighted.the world we live in today has very mixed-up priorities!cheers,rob :-)

author: coppercone2
author_rank: Super Contributor
timestamp: April 07, 2024, 07:35:31 pm
content: well its probobly still way easier to die in a car or something.A mod that will greatly improve safety on this is using some thick kapton tape over the little coil to act as insulation...

author: Zero999
author_rank: Super Contributor
timestamp: April 07, 2024, 09:19:23 pm
content: YT are funny. Videos about controversial subjects get removed because they offend the woke censors, yet dangerous videos seem to be allowed.These sorts of videos annoy me. I managed to watch it, but had to mute the crap music and set the speed to double, as it's too slow. I'm also amazed to see Altium have sponsored such rubbish.

author: coppercone2
author_rank: Super Contributor
timestamp: April 08, 2024, 03:17:24 am
content: putting a thermal fuse on the coil would help too, if that is getting hot then you risk insulation breachWith good transformer isolation I see this thing being maybe safer then a dodgy phone charger...I think the main problem might be what happens if some components start to burn, can they cause a insulation breachBut like seriously, its pretty sick that you can make a little heater like that from a CFL. It is probobly safer then playing games with direct heating from the outlet too (prison lighter)

author: strawberry
author_rank: Super Contributor
timestamp: April 10, 2024, 05:01:10 pm
content: congrats, 20W induction heater,someone can try push 50W max before transistor overheating/lachupif you dont want to do mods like in video - its same circuit found in 12V incandescent bulb electronic transformers or old ATX powersupply - connect your coil to to secondary winding and woala

author: coppercone2
author_rank: Super Contributor
timestamp: April 13, 2024, 07:43:42 am
content: hotwired!
CH340, Oscillator question - Page 1
Forum section: electronics / projects

author: JPortici
author_rank: Super Contributor
timestamp: December 24, 2021, 04:32:35 pm
content: Hi, i'm considering the CH340 as an UART-USB chip (currently using FTDI, planning to switch to MCP2221A) and i have one technical question:I've skimmed through the datasheet, i see i must connect a crystal, so i assume it can't do crystal-less USB.However i already have an oscillator on board for the microcontroller an i don't want to place a second one if i can avoid it.Can i provide the 12 MHz from the microcontroller itself?Side note, where do you buy yours in quantities like 1000pcs reel or so?

author: jimmc
author_rank: Frequent Contributor
timestamp: December 24, 2021, 07:56:09 pm
content: The CH340C, CH340E and CH340B versions have a built-in clock generator, no external crystal required. Seehttp://wch-ic.com/products/CH340.html.Jim

author: oPossum
author_rank: Super Contributor
timestamp: December 24, 2021, 08:00:10 pm
content: CH340B, CH340C, CH340E, CH340K, and CH340N do not require a crystal.Available from LCSC.

author: littleboot
author_rank: Regular Contributor
timestamp: December 24, 2021, 08:09:59 pm
content: I used the CH340T in my latest project because it was available and cheap and works as expected.However this chip requires a crystal, I have included my schematic to this post and can confirm it works as expected.

author: JPortici
author_rank: Super Contributor
timestamp: December 25, 2021, 10:10:59 am
content: However, according to the datasheet, i cannot use the internal clock if i need the chip to operate over the industrial temperature range, i guess i'll have to try for myself (or not, just use another chip)
CH341A I2C ignores clock stretching? - Page 1
Forum section: electronics / projects

author: jeremy0
author_rank: Contributor
timestamp: June 07, 2023, 07:58:09 pm
content: I'm using a CH341A module to interface to an I2C slave device based on the AtTiny85, driving the module from a Windows 10 machine using a version of the CH341PAR driver and library that I found online.It works at the lowest speed (20kHz), but not at higher speeds. (The CH341A works at higher speeds with other I2C devices.)After much experimentation, I've concluded that the AtTiny85 is applying clock stretching - which the CH341 is ignoring and clocking out bits regardless.(In short, if I advance or retard the timing of the point at which the slave releases SCL, it reveals correspondingly larger or smaller trailing portions of the CH341's SCL pulse(s), which it is evidently pumping out regardless of the slave holding SCL.)So, my questions are:(a) Is this known behaviour of the CH341A - or have I concluded wrongly?(b) If so, is it due to the CH341A's I2C implementation itself, or to the Windows driver?(c) If it's due to the driver, are there driver versions that support clock stretching?(d) If it's the chip, is it hardwired behaviour, or is there a way to control it?Many thanks!
CH341T EEPROM usage - Page 1
Forum section: electronics / projects

author: bson
author_rank: Unknown
timestamp: December 25, 2017, 11:31:46 pm
content: I'm considering the possibility of having a CH341T (serial to USB) chip share a small 24LC16 EEPROM with a microcontroller. The CH341T only ever accesses the first 256 bytes, and this way the uC could configure it, or the CH341T itself could be used to configure it, but having control over how the endpoint presents itself entirely through the firmware would be nice. I'm thinking if the CH341T only ever accesses the EEPROM during power-on, then the uC could simply hold off accessing it for some time period (which can be scoped out easily) after POR. But if the 341T accesses the EEPROM whenever a cable is plugged in, or the bus enumerated, or... that could be somewhat problematic. I don't want to deal with a multi-master bus setup. Other than this, my assumption is it floats SCL/SDA when it's not using it. Unfortunately, the datasheet doesn't really discuss this in more detail. The uC SCL/SDA pins come up as GPIO set to input, no internal pull resistors, so that part would work fine.So, I thought I'd ask and see if anyone else here has done legwork on this before I breadboard it...
WCH CH592F OpenOCD issues - Page 1
Forum section: electronics / projects

author: cheeseburger
author_rank: Contributor
timestamp: April 11, 2025, 10:27:19 pm
content: Anyone any idea what magic the WCH LinkE / CH592F needs so it talks with OpenOCD?My Hardware works fine with MounRiver IDE. I can start a debug session and everything works. I can even launch OpenOCD one single time after a MounRiver IDE Debug session. But afterwards it doesn't work anymore. No matter if Windows or Linux.When it doesn't work it just tells this:Code:➜ bin sudo ./openocd -f wch-riscv.cfg -c init -c halt -c "flash erase_sector wch_riscv 0 last" -c exitOpen On-Chip Debugger 0.11.0+dev-02415-gfad123a16-dirty (2024-11-20-13:09)Licensed under GNU GPL v2For bug reports, readhttp://openocd.org/doc/doxygen/bugs.htmlInfo : only one transport option; autoselect 'sdi'Warn : Transport "sdi" was already selectedReady for Remote ConnectionsInfo : WCH-LinkE mode:RV version 2.16Error: WCH-Link failed to connect with riscvchipError: 1.Make sure the two-line debug interface has been opened. If not, set board to boot mode then use ISP tool to open itError: 2.Please check your physical link connectionUsing MRS_Toolchain_Linux_x64_V210.tar.xz.

author: cheeseburger
author_rank: Contributor
timestamp: April 14, 2025, 09:15:18 pm
content: Fixed with this:Code:./openocd -f wch-riscv.cfg -c "chip_id CH59x" -c init -c halt -c "flash erase_sector wch_riscv 0 last" -c exit
Chaising smps noise - Page 1
Forum section: electronics / projects

author: ZachR
author_rank: Newbie
timestamp: March 31, 2011, 07:10:26 pm
content: Hi all,I'm working on a circuit that uses a LM5009 SMPS set to output 5.8v (using the boiler plate low noise schematic from the data sheet). I am then feeding that into a LM3490 regulator through a 600ohm/1Mhz ferrite bead and a .1u ceramic input cap. On the output of the regulator there is a .1u ceramic, a 4.7u ceramic and 100u tant on the output (obviously going to gnd).On this image channel 2 is the input to the regulator, channel 1 is the output of the regulator:I would really like to remove that negative going spike on the output. However, nothing I try seems to touch it. Any thoughts?

author: Simon
author_rank: Unknown
timestamp: March 31, 2011, 07:31:53 pm
content: so what is the Vpp of the noise ?

author: ZachR
author_rank: Newbie
timestamp: March 31, 2011, 07:59:58 pm
content: According to the scope image I'd say ~100mv.

author: Simon
author_rank: Unknown
timestamp: March 31, 2011, 08:04:50 pm
content: oh yes didn't spot the v/div at the bottom. Well I'm no SMPS expert, have you checked that you have used the correct component values and that the inductor will take the peak switch current (not output current)

author: ZachR
author_rank: Newbie
timestamp: March 31, 2011, 08:17:28 pm
content: I used National's "Webench" for the component selection. The output of the smps seems to match the Webench simulation perfectly. The inductor is slightly warm to the touch, but seems to be fine. The simulation predicted the ~100mA p-p ripple coming out of the smps and sure enough, that's what I measure. The LM3490 does reject some of the lower frequency ripple, but it seems to add that big negative going spike (which is causing issues . That spike could be the regulator overshooting due to that small pulse seen on the input (channel 2 in the image). But I would have though my capacitor array on the regulator's output would have helped that.

author: Simon
author_rank: Unknown
timestamp: March 31, 2011, 08:24:58 pm
content: hm I'm not sure your inductor should be warm, what amperage are you passing ? you can put a secondry LC filter on the output to help cull noise.

author: am2pgs
author_rank: Contributor
timestamp: April 01, 2011, 12:35:35 am
content: This looks like mostly Ground noise to me.If not already so, try the following:a) Are you sure this is not a measurement artifact. Place the probe and it's ground directly across your filter capacitor at the regulator output and see if the spike is still there.b) Make sure the return ground path of your SMPS circuit is not through the linear regulator.
chance of repairing this - Page 1
Forum section: electronics / projects

author: AdamB
author_rank: Newbie
timestamp: August 07, 2018, 08:27:06 am
content: Hi all,I recently obtained a broken miller digital elite welding helmet and are looking into buying a new electronic lense. I was just wondering if it would be possible to repair the broken one. On one of the battery ports (it takes two 2450 batteries) the resistance between the contacts is 9.6 megaohms and on the other one the resistance is 0.44 kiloohms. the issue with the helmet was that the right side did not auto darken. the reason I believe it might be difficult to repair is that the components are mainly microcomputers and micro transistors. this is the component:https://www.ebay.com/p/Miller-Digital-Elite-Auto-darkening-Welding-Lens-256469/1603495817?iid=390581441171

author: helius
author_rank: Super Contributor
timestamp: August 07, 2018, 08:44:10 am
content: Does this device use a flexible printed circuit?

author: AdamB
author_rank: Newbie
timestamp: August 08, 2018, 04:39:05 am
content: yes it is surface mount although I think I repaired it so all good

author: james_s
author_rank: Super Contributor
timestamp: August 08, 2018, 09:10:32 pm
content: With anything like this, whether or not you can reasonably repair it usually comes down to whether you can get it apart without completely destroying it.

author: Doctorandus_P
author_rank: Super Contributor
timestamp: August 09, 2018, 03:03:57 pm
content: USD 245 ?Gosh.A quick search for "welding helmet LCD: on Ali pops up results starting from around USD10:https://www.aliexpress.com/wholesale?SearchText=welding+helmet+lcdI prefer the LCD's without battery. Less to go wrong, and therefore hopefully more reliable.It's very annoying when your helmet turns itself off after 15 minutes, and you get to see spots swimming in front of your eyes because your helmet didn't turn on while welding.These do however often have smaller size of the LCD, but I've never found that a problem, as long as I can see the the area a few cm around the place I'm welding.But your USD245 version likely has a better build quality and is worthy of a repair.It is unikely that the uC is broken. It is more likely a broken wire or bad solder joint.It may also be some dirt (metal dust from grinding etc) has gotten into the electronics, try blowing it with an air compressor.I'm curious what the circuit of the electronics of such a welding helmet looks like. I would at least expect a conformal coating.Can you post some pictures?
Change designates in multi-channel - Page 1
Forum section: electronics / projects

author: amirkargar110
author_rank: Contributor
timestamp: September 16, 2017, 10:46:40 am
content: HelloI have amultichanneldesign in Altium designer.I want to start for example my designator numbers form Number 1000.in schematic it changes. but in pcb doc after updating does not change. and it remains like before.what should I do to change my designators inpcb pagein amultichanneldesign?
Change multimeter resistors - Page 1
Forum section: electronics / projects

author: Tioleco
author_rank: Contributor
timestamp: July 08, 2011, 12:27:41 am
content: I have an analog multimeter with 1% resistors , and I want to exchange them for 0.5% or better, be worth doing that?

author: PeterG
author_rank: Frequent Contributor
timestamp: July 08, 2011, 01:30:28 am
content: A change of 0.5% wont make a visible change to an Analog meter. There is generally a larger degree of error on the meters mechanical movement.Regards

author: Kiriakos-GR
author_rank: Super Contributor
timestamp: July 08, 2011, 01:35:10 am
content: You will archive a bit better stability against environmental temperatures.If it please you do it, why not ..

author: Zero999
author_rank: Super Contributor
timestamp: July 08, 2011, 04:07:59 pm
content: If the meter is trimmed in some way, replacing the resistors will make it less accurate, not better.

author: Kiriakos-GR
author_rank: Super Contributor
timestamp: July 08, 2011, 04:40:36 pm
content: I have not see in my life yet ... production items to be trimmed in any way.

author: Fox
author_rank: Regular Contributor
timestamp: July 08, 2011, 08:29:06 pm
content: If you change the resistor, at least you have to calibrate your MultimeterBut want to do that, do it with the original resistors, so you now where your meter deviates and how much.So i won`t go into the effort of replacing the resistors.If you really wan`t a more accurate meter you have to change at least your voltage reference to a better one and or your ADC, but this is not as easy as it seams.So if you want a better meter the easiest way would be to buy a better one.As for the analog scale most of them have accuracies about 2%, so calibrating your meter is the best way to improve your measurements.
... - Page 1
Forum section: electronics / projects

author: cleaningOut
author_rank: Contributor
timestamp: May 10, 2017, 02:31:52 am
content: ...

author: Rerouter
author_rank: Super Contributor
timestamp: May 10, 2017, 02:41:38 am
content: Why not just create yourself a gateway, can to ethernet. that your project then talks to the vehicle through,I would say it would be nonviable to set about converting every ECU and can connected module in the vehicle to ethernet and not have everything go horribly wrong.Being a nissan there is likely to only be 1 -3 canbuses inside the vehicle

author: DBecker
author_rank: Frequent Contributor
timestamp: May 10, 2017, 02:57:31 am
content: It is technically infeasible to change from CAN to Ethernet. Doubly so if you don't control the code base.Even if you could sort out the multicast nature of CAN frames (CAN IDs are not addresses), you wouldn't be able to reconcile the error model and wake-up behavior.There is no general rule about self-driving cars, but most appear to use CAN bus for operation. Sensors and actuators need either massive amounts of I/O or trivial communication -- there isn't a middle ground.

author: todd_fuller
author_rank: Contributor
timestamp: May 10, 2017, 05:14:47 pm
content: Beyond the technical process of converting from CAN to something else, I'd investigate the ethernet versions meant for safety-cricital applications as a good starting place. Self-driving may not to very interesting if it can't stop/turn/accelerate because some sensor is flooding the network.

author: james_s
author_rank: Super Contributor
timestamp: May 10, 2017, 06:15:38 pm
content: The idea of a DIY 4,000lb autonomous machine capable of 70+MPH full of all sorts of hardware and software hacks is frankly, terrifying. Please do not attempt to operate such a vehicle on public roads, or anywhere near me.

author: stevelup
author_rank: Regular Contributor
timestamp: May 10, 2017, 06:55:44 pm
content: I'd be amazed if this is not far more complicated than you think.My current car has loads of different busses4 x separate K-CAN2 x separate PT-CANMOST (digital audio amongst other stuff)Multiple (approx half a dozen) FlexRayEthernetD-CANMultiple LIN busNumerous individual CAN bussesI'd be amazed if you could take control of a modern car without many and various interfaces.
Changing a Branch's Track Thickness in Eagle CAD - Page 1
Forum section: electronics / projects

author: bjcuizon
author_rank: Frequent Contributor
timestamp: February 21, 2017, 04:04:39 am
content: Hi, I'm currently working on a power supply board in eagle. How do you change the track thickness of a power rail's branch.i.e. I have a thick power rail from the transformer to the regulator, and on the way is a small op-amp to buffer the positive output to the negative reg.Now, the op-amp only draws a little amount of current and I don't need that thick rail. Does anyone know how to change it?

author: f1rmb
author_rank: Regular Contributor
timestamp: February 21, 2017, 04:48:42 am
content: Hi,ch wi<enter>then click on the "track"Cheers.---Daniel

author: t1d
author_rank: Super Contributor
timestamp: February 21, 2017, 07:22:42 am
content: Daniel is correct... But, if you are new to Eagle, here are the complete steps...- Find the "Wrench" symbol, in the right-side tool list. This is the Change Function. Click on it.- Scroll to the bottom of its drop-down list and find the "Width" option.- Click on that and scroll down to the width you would like to use.- Click on that width.- The cursor is now loaded to change whatever tracts you tap on with the new width.- Tap on the track.- You may have to click on the rats nest to update the screen.If you are just starting to learn Eagle, you may want to read the recent news about how it will be offered/sold, going forward. The new owner is going to subscription based pricing. Lots of folks are not pleased about that. You might rather invest your learning effort in something else. KiCad is a free, open source alternative.

author: Zom-B
author_rank: Regular Contributor
timestamp: February 21, 2017, 03:41:53 pm
content: Probably easiest:When you layout the track, click on the ratsnest* near the pad where to start.While the thick trace sticks to your cursor, change the width in the tool bar at the top. Voila.(Trap for beginners: traces do not start by clicking on a pad, as in other PCB packages, but by clicking on any ratsnest eminating from it. If no ratsnest is enimating from it, placing a trace is not possible, although you can place a 'line' which essentially does the same.)

author: bjcuizon
author_rank: Frequent Contributor
timestamp: February 23, 2017, 07:25:51 am
content: Hi t1d, I'm not that new to eagle but I just don't know how to change a specific track's thickness. But thanks for all the help, it solved my problem.By the way, I downloaded the eagle application installer years ago when it was still free. And now I don't know what has come into the minds of Autodesk
Changing a VU circuit - Page 1
Forum section: electronics / projects

author: carbon dude oxide
author_rank: Frequent Contributor
timestamp: September 29, 2013, 07:33:16 pm
content: Hello i have a small VU meter project going at the moment, and i have modified this circuit so far so that it is able to vary the brightness of the LED strip acording to the loudnessHowever i have run into a problem currently all 3 transistors on there are: BC547B 's and the amount of LED's i want to drive from this is a little bit too high unfortunatlyI would like to replace T3 to a mosfet to be able to handel about 8-10A (12m of RGB LED strip)How would i go about modifying this circuit so that it uses a mosfet? Or can i put several of the BC547B in parralel with ballast resistors?

author: madires
author_rank: Super Contributor
timestamp: September 29, 2013, 09:13:17 pm
content: If you would PWM the LEDs then it would make sense to use a MOSFET. I'd go for a darlington configuration with a BD135 and some 2N3055.

author: dannyf
author_rank: Super Contributor
timestamp: September 29, 2013, 09:35:03 pm
content: QuoteA (non-practical) solution would be to use T3's output to drive a (linear) mosfet driver / mosfet.The only practical solution is to to use T3's output to modulate a pwm driver that drives the mosfet. One example would be to use a simplified version of your existing circuit to drive a 555 and then a mosfet, either directly or through a driver, depending on the mosfet used.
Changing buck converter to one with more current possible? - Page 1
Forum section: electronics / projects

author: Chris02
author_rank: Contributor
timestamp: September 10, 2013, 01:38:53 pm
content: Hey!In my free time I often repair white goods (dryer, washing machines etc.).And if the power electric is dead in most cases it is a dead buck converter e.g.lnk30xortny26x.So my question is can I upgrade e.g. lnk304 to lnk305 without to risk that other parts will die then (e.g. what about the saturation of transformer)?I guess you want to see a circuit but I haven't it. I can only try to reverse it from a pcb if it defenetly needed.I hope anybody can help me!Thanks!RegardsChris
changing Hsteresys location on op - Page 1
Forum section: electronics / projects

author: brg
author_rank: Newbie
timestamp: January 21, 2018, 04:58:57 pm
content: Hi All,I am using a 2 channel opamp, one to detect changes and second to output high. on origin, on channel 2, Pin#5 was connected to reference and pin#6 to channel 1 output (ant it was outputting Low when threshold happened). that worked fine. now i need it to output high (instead of low), hens I switched locations between 6/5 as in the attached schematic.can any of you experts advice if C12 can stay where it is or to connect it to pin#5 instead?In addition, I added R9 for pull down (to keep the line always low except when the opamp will output high), question is if R9 is necessary?Thank you on advance,Barg

author: John Heath
author_rank: Frequent Contributor
timestamp: January 21, 2018, 06:37:23 pm
content: Thank you thank you. Have been looking for an excuse to use my new Tina simulator. This should light up the LED at about 100 m volts AC depending on where you set pot 1. This can be separate from the audio only requiring a sample so as not to distort the sound. If you think it will do I can send the TSC file.

author: brg
author_rank: Newbie
timestamp: January 21, 2018, 06:42:28 pm
content: Hi John,Thank you for your reply but I don't understands your reply and how its relevant to my two questions on the schematic (C12 location and R9)?

author: John Heath
author_rank: Frequent Contributor
timestamp: January 21, 2018, 07:16:51 pm
content: You have an unconventional op-amp configuration using power supply + rail as an input? There are more conventional ways to do this. The problem is do "what"? Could you expand on what your goal is. As far as R9 is concerned the op-amp has a gain of around 60 DB , 1000 to 1 voltage , so R9 will not do much other than annoy the op-amp with extra current required. What is it that you would like to accomplish?
Changing reference planes on multilayer board - Page 1
Forum section: electronics / projects

author: c64
author_rank: Frequent Contributor
timestamp: September 21, 2021, 04:52:33 am
content: Standard stackup for 4 layers: signal - gnd - power - signalIf a signal trace is on top layer, the return current goes under the trace. When trace jumps to bottom plane, everyone recommend to place decoupling capacitor as close to via as possible. However, I can't understand how return current will flow on the power plane.

author: ejeffrey
author_rank: Super Contributor
timestamp: September 21, 2021, 05:29:55 am
content: For the high frequency signal which is what you care about the power plane is just as good as the ground plane for a return path as long as you provide a capacitor for it to jump planes.If you think about a CMOS output, it is a pair of MOSFET switches connected to 0V and Vdd. So the return path ultimately goes to both of those depending on which transition you are looking at. But you are supposed to have good decoupling by the transmit and receive ends so the current pulse can go wherever it needs to.

author: c64
author_rank: Frequent Contributor
timestamp: September 21, 2021, 06:35:29 am
content: I made a simple schematics with two transistors, one driving another.And two pcb layouts, one with trace on top layer, another with trace jumps to the bottom layer and then back to top. Second layout has two capacitors near the vias. I also show the return current on the ground and power planes and voltage at some points.So what voltage would be at the power plane?
Changing sound based on input - Page 1
Forum section: electronics / projects

author: Domagoj T
author_rank: Frequent Contributor
timestamp: January 13, 2021, 09:47:45 pm
content: A potential client asked if I'd be interested in building (among other, much simpler, things) a system which would simulate a jet airliner sound based on throttle lever position. It's for an aircraft simulator targeted at 5-10 year old kids in a playground type of facility, so there is no particular need to go overboard with fanciness, and it's really not important what airplane it sounds like as long as it roughly sounds like jet engines reving up and down based on throttle lever position.Quite frankly, I have no idea what is this technique called and what keywords I should search forI'd like to avoid having to install a full PC with MFSX and HOTAS, so a standalone microcontroller solution would be optimal.One idea I have in my mind is using an off the shelf solution in a form of a model train sound decoder, but I have no idea how would I go about replacing the sound in it, or more specifically how to engineer the sound (formats, structure etc).This might work, but has its own issues, so I'm trying to investigate better options.Any thoughts?

author: Domagoj T
author_rank: Frequent Contributor
timestamp: January 13, 2021, 09:56:39 pm
content: Hmm, just stumbled upon this little gem:https://www.electroschematics.com/sound-generator-jet-engine-aircraft/It just might be a solution to my problem. I'll see if I can buy the 2844 tomorrow and build the thing.Of course, I'm still open for other suggestions.

author: Benta
author_rank: Super Contributor
timestamp: January 13, 2021, 10:02:28 pm
content: Buy an "Arbitrary Waveform Generator" on the web somewhere. They can be had for 50...100 Euros, go for a two-channel (or more) model.Then play around with the sounds.For a jet engine you'll need white noise and a varying sine wave (or perhaps another shape) mixed together.When you've found the right sound, you'll also know how to build it.
Changing the output RF power of nRF24l01+ PA LNA module possible??? - Page 1
Forum section: electronics / projects

author: Dhanushka
author_rank: Regular Contributor
timestamp: July 15, 2020, 09:28:57 pm
content: Hi,I m looking for some way to reduce the RF output power of the nrf24l01+ PA LNA module with 2dBi antenna for a project work. I m not coming from communication background. So, it is please that someone can explain this with proofs.It is possible to change the RF power of the nrf24l01+ chip. But I m wondering whether it can be done for the module with power amplifier and antenna. This is possible if the RF amplifier change the output power under the input power. So, I need to know about the power amplifier is working as this or whatever the input power the output power the output power in same 20dB state. Power amp datasheet is so confusing. That's why I m asking a help of you.Thanks
Channel Equalization in DSP processor - Page 1
Forum section: electronics / projects

author: sagnikbasu
author_rank: Contributor
timestamp: March 06, 2017, 03:58:43 pm
content: Hi.I am trying to implement an adaptive channel equalization techniques to reduce noise and ISI effect of a channel in a DSP processor. I am using a Texas Instrument OMAP LCDK board for this project.I need some guidance as I am quite new to the realm of Digital Signal Processors. Can anyone tell me how to proceed with this topic?Thank you for your help.

author: mark03
author_rank: Frequent Contributor
timestamp: March 06, 2017, 05:51:02 pm
content: An adaptive filter is an extremely difficult first project to implement in hardware. So many things can go wrong. Start with a fixed FIR filters, verify, and go from there.

author: sagnikbasu
author_rank: Contributor
timestamp: March 06, 2017, 06:09:56 pm
content: Thanks .If you know any good resource, do post their link.
Chaos Illutrated by the Analog Computation of the Lorenz Equations - Page 1
Forum section: electronics / projects

author: TQEngineering
author_rank: Newbie
timestamp: March 03, 2016, 12:47:31 am
content: I've always been really interested in Chaos theory, so I decided to build a nice PCB based on this circuit by Paul Horowitzusers.physics.harvard.edu/~horowitz/misc/lorenz.htm. The goal is to provide a really interesting demonstration that helps educators and enthusiasts to inspire students/friends to learn more about science and engineering. Check out a video of the circuit in action here:.The idea that tiny changes can lead to dramatic effects down the line easily leads to internal crises where I question all of my life decisions. Chaos can be seen all throughout nature like in turbulence, double pendulums, the weather, economics, etc. It's definitely worth some time researching if you're unfamiliar.The circuit design that makes this happen is completely analog (super cool) and pretty digestible. I'll be tracking updates on the project on my Hackaday pagehttps://hackaday.io/project/9071-chaos-computer, and you can pick one up on Tindie!www.tindie.com/products/TQEngineering/chaos-computer/.Let me know what you think!

author: tautech
author_rank: Super Contributor
timestamp: March 03, 2016, 12:52:49 am
content: Welcome to the forum.Nice.Have you seen member GK's work"https://www.eevblog.com/forum/projects/t20347/For more check his website.

author: TQEngineering
author_rank: Newbie
timestamp: March 03, 2016, 01:02:04 am
content: Very cool, thanks for posting! I love how GK didn't explain the circuit and challenged everyone to figure it out, awesome.

author: chris_leyson
author_rank: Super Contributor
timestamp: March 03, 2016, 01:19:59 am
content: Nicegood to see some analogue engineering. Lorenz, Chua, Mandelbrot and don't forget Van Der Pol.
Character LCD vs sunlight - Page 1
Forum section: electronics / projects

author: poorchava
author_rank: Super Contributor
timestamp: March 12, 2019, 09:37:25 am
content: Do you have any experience with character LCDs in products, where they are exposed to direct sunlight? Our customer mentions a plastic enclosure with transparent polycarbonate cover, so that service techs can see what is written on the LCD. The problem is, that I can't seem to find any info on how those displays withstand prolonged exposure to direct sunlight. I know that most of the electronic stuff (passives, ICs, PCBs etc) are very resistant to it and there should not be any problem, but the LCD is a mistery.Do you have any experience that you can share?

author: Gyro
author_rank: Super Contributor
timestamp: March 12, 2019, 12:17:10 pm
content: From your description is sounds like a long term exposure situation - short term there would be no issue.It seems to me that you have two problems - both ends of the light spectrum, UV and IR. UV can damage the polariser film. Luckily the window (if itisdefinitely Polycarbonate) has good UV blocking properties.At the other end of the spectrum, IR is more of a problem. LCDs don't like very high temperatures, initially you get a shift in contrast, then, at higher temperatures, they go black. You need to keep the LCD reasonably cool - if it really is in direct sunlight then the customer needs to arrange for some level of ventilation (or at least, air circulation) over the display. This is going to depend on the size of the enclosure, sealing, ambient temperature, etc. Worst case, some sort of thermally conductive pad to an aluminium chassis part behind the display might help.One final problem might be moisture / condensation, but that will probably affect other things in the enclosure too.

author: wraper
author_rank: Unknown
timestamp: March 12, 2019, 12:21:34 pm
content: AFAIK LCD degrade under UV exposure. Also consider that it may heat up quite extremely under direct sunlight which may be bigger problem.