hybridfree/eevblog-posts huggingface dataset:
Freelancer.com & can one post here instead if looking for someone to write code? - Page 1
Forum section: electronics / general

author: peter-h
author_rank: Super Contributor
timestamp: September 25, 2022, 10:10:18 am
content: I frequently have a need for someone to write a little utility, mostly win32 command line stuff.One recent one was a crc32 appending program. Another was an aes256 encryptor (and no, existing progs didn't work for various reasons e.g. they add a header). Another was a simple GUI prog which displays a 64k block (as a square of 256x256 sprites) in a colour coded manner so you can easily see unused FreeRTOS stack space etc (really handy). Most of these were done for under $100, and done well. The system does basically work, and provides work for clever people in less wealthy countries, so that's great.Right now I am trying to get a serial loopback program written which can work not only between different com ports but also do loopback on the same single com port. Really simple and anybody who knows MC VC/C++ and how to drive com ports could do this in a few hours. But this one is a real struggle. One $100 guy, Ukraine (as many on Freelancer are, or pretend to be, and I know a lof of these are very clever), wrote something which seemed to sort of work but forgot about the single port case. I think I have found somebody to finish it off, for $120. I actually have a GUI loopback tester from 2004 which would do the job but it doesn't work with the single port case; hacking that would be another option.The biggest problem is time wasters (half of India and Pakistan responds within 1 minute, with bidsso they obviously never read the spec) and people who cannot speak or understand English. The last one is the biggest issue - comms is really hard. Then you get the "Russian culture" cases who tend to be rude (I am from that part of the world myself, but from a place Russia invaded a while ago). There are people on there from the "West" but they want silly money - a full contractor daily rate, and if paying that, I could get it done by people I know, here.Is there some other site out there which works better? Or can one post on EEVBLOG? I know incidentally there are people here who are damn clever and obviously could do it.

author: RoGeorge
author_rank: Super Contributor
timestamp: September 25, 2022, 11:57:26 am
content: There is an EEVblog section to post jobs:https://www.eevblog.com/forum/jobs/

author: peter-h
author_rank: Super Contributor
timestamp: September 25, 2022, 12:13:37 pm
content: Those are normal jobs though, no?

author: RoGeorge
author_rank: Super Contributor
timestamp: September 25, 2022, 02:10:03 pm
content: Have you read the "READ THIS" sticky and locked post there, in the jobs section?

author: T3sl4co1l
author_rank: Super Contributor
timestamp: September 25, 2022, 03:30:59 pm
content: What's wrong with netcat (use Cygwin)? Or:https://superuser.com/questions/14501/are-there-netcat-like-tools-for-windows-which-are-not-quarantined-as-malwareTim

author: peter-h
author_rank: Super Contributor
timestamp: September 26, 2022, 06:30:06 am
content: QuoteYes - it statesQuote
[YouTube] Open Circuits: Eric cuts through electronic components... - Page 1
Forum section: electronics / general

author: Gyro
author_rank: Super Contributor
timestamp: October 11, 2022, 06:52:34 pm
content: Sorry, you were beaten to it...https://www.eevblog.com/forum/chat/open-circuits-the-inner-beauty-of-electronic-components/

author: eti
author_rank: Super Contributor
timestamp: October 11, 2022, 08:23:23 pm
content: Quote from: Gyro on October 11, 2022, 06:52:34 pmIn one respect, yep, but this is a video. Anyway, best to have the complete picture - and this completes itI agree this video is in a post IN that thread, but it's easier to find when it's a topic
"We are proud of our product!" (ESP32 listing fail) - Page 1
Forum section: electronics / general

author: eti
author_rank: Super Contributor
timestamp: September 23, 2022, 03:35:07 am
content: Spot the component fail... and this is a SALES LISTING IMAGE!https://www.amazon.co.uk/ESP-32S-Development-2-4GHz-Bluetooth-Antenna/dp/B071JR9WS9/ref=sr_1_1?crid=2274EO176ZGA1&dd=Bvb0eDh5wAnCdi_QJcDQCg%2C%2C&keywords=esp32-s2&qid=1663903544&refinements=p_90%3A5381145031&rnid=5381144031&sprefix=esp32-s2%2Caps%2C79&sr=8-1

author: pcprogrammer
author_rank: Super Contributor
timestamp: September 23, 2022, 06:15:00 am
content: yikes, that is bad advertisingNot just the boot switch, but the solder job on the ESP module does not look that good either. Probably made on a Monday morning.

author: Ed.Kloonk
author_rank: Super Contributor
timestamp: September 23, 2022, 06:24:07 am
content: Honesty in online retail. For once.
Matlab Zero-Phase Digital Filtering Question - Page 1
Forum section: electronics / general

author: joeqsmith
author_rank: Super Contributor
timestamp: September 22, 2022, 12:41:25 pm
content: I am attempting to replicate MatLab's filtfilt function. I'm curious if we have any MatLab users that may be able to explain the details of how they handle the start-up and ending.Quotehttps://www.mathworks.com/help/signal/ref/filtfilt.html

author: ejeffrey
author_rank: Super Contributor
timestamp: September 22, 2022, 02:44:52 pm
content: I'm not sure exactly how filtfilt does it but I think you start with the filtic function:https://www.mathworks.com/help/signal/ref/filtic.htmlCalling filtic with x and y values corresponding to the first value in the data (assuming a low pass filter with DC gain 1) will eliminate the effective discontinuity at the start. Depending on the order of the base filter you could set an initial value that matches more of the derivatives of the signal.

author: radar_macgyver
author_rank: Frequent Contributor
timestamp: September 22, 2022, 02:59:21 pm
content: You can find an implementation in the octave-signal package. The comments to that implementation refer to"Hardware-efficient technique for minimizing startup transients in Direct Form II digital filters"by Likhterov and Kopeika.

author: joeqsmith
author_rank: Super Contributor
timestamp: September 22, 2022, 04:00:04 pm
content: QuoteI don't believe that would be close.***I think I miss understood the term mirrored. I was thinking just the along the vertical axis but I suspect they mean both.***Coding the 2 axis mirror like shown using a window 3X the filter order,its slightly worse than my previous attempt.***Bug in code. Very close now. Plot comparing MatLab filtfilt with using the above. Basically feeding a series of noise into each filter.Thanks for the help.
PCB Mount Transformer Pin Spacing ??? - Page 1
Forum section: electronics / general

author: EPAIII
author_rank: Super Contributor
timestamp: September 22, 2022, 04:37:11 am
content: I have purchased a PCB mount power transformer, Hammond 229A230. It has dual coil primary and secondary so each can be either 115V or 230V. I will be using it to step up from 115V to 230V and the project will only need around 12mA. It is rated at 6VA so it can supply 25mA: their numbers, not mine. So far, so good.Since this will be a one-off device, I plan to assemble the power supply on perf board. Sounds easily doable. But when I measured the spacing of the 8 pins I came up with a 1.6" dimension between the primary and secondary rows. And the pins in each row are spaced at 3/8" (0.375") apart.It is a part that is intended to be mounted on a PCB. There is no other provision for mounting it. But in one direction it fits on a 1/10" grid and on the other on a 1/8" grid. This is not the first time I have seen this kind of pin spacing. Transformer manufacturers have been doing this type of thing for many years. And there is sufficient space within the outline of the transformer to easily either widen that 3/8" to 0.4" or to reduce it to 0.3".I will be able to do a work-around as I have done in the past. File the holes in a standard perf board with a 0.1" grid sideways to allow the pins to pass through the board. And then they can be bent over the foil before soldering. I am not asking how to use it: I have done this a number of times in the past.But what I want to know is WHY? Why do the transformer manufacturers do this? I could understand if it was a 1/8" or 1/16" grid in both directions. I could understand if it was a 1mm grid in both dimensions. Oh, and I did check. It is not metric in either direction. And I could understand, actually I would expect that it would be a 0.1" grid. The 1.6" dimension tells me that the designer did know that a 0.1" grid was a more or less standard spacing for components in this size range. So why after making one spacing compatible with a 0.1" grid did they then change to a 1/8" grid for the other direction? I can see no sensible reason. Anybody have an explanation?

author: mariush
author_rank: Super Contributor
timestamp: September 22, 2022, 09:16:24 am
content: You would still have to remove the copper around the holes near the holes where the transformer pins go in, because you don't want to have 230v jump across terminals (what if you get some water on the pcb for example)Instead of soldering pins into the prototyping board, you could flip it so the pins are towards the top and enlarge a few holes in the pcb to insert some zip ties through the pcb holes and then have the zip ties around the transformer. If you want to be overkill, add some rubber or sponge between the pcb and plastic of transformer to reduce noise from vibrations in transformer.Then solder your own wires to the pins, and put some heatshrink over the pins.
Video: Colorized late 1940's California 'burbs + street view spots in comments - Page 1
Forum section: electronics / general

author: Ed.Kloonk
author_rank: Super Contributor
timestamp: September 18, 2022, 11:53:44 am
content: Very stunning video. Sift through the youtube comments to find the names of the streets.Second half of video has a few remaining houses, but their remaining features are so distinctive, you can see the differences elsewhere.QuoteThere are more you can find. Have fun.

author: Halcyon
author_rank: Unknown
timestamp: September 19, 2022, 10:39:47 pm
content: There are some similar "street view" photos from the US in the 1980's as well...https://www.beautifulpublicdata.com/highway-photologs/

author: Sal Ammoniac
author_rank: Super Contributor
timestamp: September 20, 2022, 05:22:49 pm
content: Here's my favorite, from an earlier era: a trip down San Francisco's Market Street four days before the earthquake in 1906:

author: Ed.Kloonk
author_rank: Super Contributor
timestamp: September 21, 2022, 03:07:19 pm
content: Do people who live in SF have one leg shorter than the other? Hills are so steep.Quote
water shortage and water purification plants - Page 1
Forum section: electronics / general

author: strawberry
author_rank: Super Contributor
timestamp: September 20, 2022, 07:57:21 pm
content: is it possible to reuse waste water and not drain it in river or oceanit is expensive to purify it as drinking water but maybe good enough as is for fields

author: TimFox
author_rank: Super Contributor
timestamp: September 20, 2022, 09:52:05 pm
content: https://en.wikipedia.org/wiki/Reclaimed_water

author: bdunham7
author_rank: Super Contributor
timestamp: September 20, 2022, 09:55:16 pm
content: Yes, 'recycled' water from sewage treatment plants is used for irrigation here in California. Gotta keep those golf courses green!

author: NiHaoMike
author_rank: Super Contributor
timestamp: September 20, 2022, 10:10:13 pm
content: https://www.wired.co.uk/article/urine-fertiliser-growing-plants

author: ejeffrey
author_rank: Super Contributor
timestamp: September 20, 2022, 10:57:00 pm
content: Quote from: strawberry on September 20, 2022, 07:57:21 pmYes it's possible, and yes it's a good idea. It's not even really expensive. It's not free of course, it's more expensive than pumping water out of a hole in the ground, but it's pretty cheap compared to retail residential water prices, at least anywhere you would consider this (say the western US).We can make treated wastewater cleaner than all of our drinking water standards, although not all water treatment plants do this. It's generally not used for that because too many people think it's gross and call it "toilet to tap" -- and mean that in a bad way. So treated wastewater is usually used for landscape irrigation or ground water replenishment -- where it is then pumped back out of the ground, treated a second time, and then distributed as drinking water.
Tab of TO-220 IRFB7545PBF - failure mode? - Page 1
Forum section: electronics / general

author: BreakingOhmsLaw
author_rank: Frequent Contributor
timestamp: September 18, 2022, 03:25:58 pm
content: Hi everybody,the datasheet of the IRFB7545PBF shows no connection for the tab of the TO-220 package. My guess is that it is isolated by an oxide layer from the other pins.But what would the failure mode be? Could it get connected to any other pin?https://www.infineon.com/dgdl/Infineon-IRFB7545-DataSheet-v01_01-EN.pdf?fileId=5546d462533600a401535619e1ca1e66

author: SeanB
author_rank: Super Contributor
timestamp: September 18, 2022, 03:40:50 pm
content: Isolated tab can, with overload that leads to overheating, short out to the drain, probably around the time drain, gate and source all bond into a single conductor, just about a millisecond before the smoke escapes at high velocity. Best o make sure this will not occur, or to at least add in extra protection physically, so an insulator will probably be a good idea, or an isolated heatsink, or connected to source instead for the low side, so a failure will cause a fuse to blow to provide protection. Not a good idea to have it connected to ungrounded metal heatsink at all, so for class II use you would always add in the extra isolation of a thermal pad and insulating clamp down hardware.

author: wraper
author_rank: Unknown
timestamp: September 18, 2022, 03:44:00 pm
content: Tab is almost guaranteed to be connected to center pin, it's just how TO-220 lead frame is normally made. As datasheet says nothing about isolated tab, I would not expect it to be the case.

author: BreakingOhmsLaw
author_rank: Frequent Contributor
timestamp: September 18, 2022, 03:51:17 pm
content: Quote from: wraper on September 18, 2022, 03:44:00 pmGuess I'm ordering a sample to measure that. Thanks!

author: strawberry
author_rank: Super Contributor
timestamp: September 18, 2022, 05:04:54 pm
content: isolation voltage ?

author: magic
author_rank: Super Contributor
timestamp: September 19, 2022, 01:06:46 pm
content: Some triacs have isolated tabs and this is advertised in the datasheet and maximum isolation voltage rating is provided (hundreds or low thousands of volts).In absence of such data, there is no reason to assume it isn't just the usual TO220 construction: the tab and the center pin are cut from one piece of metal and soldered to the back of the die, which in case of vertical MOSFET is the drain.If you require isolation, don't bother ordering it and look for some alternative in TO220F. Or ask the manufacturer for clarification, this information should be in the datasheet.

author: thm_w
author_rank: Super Contributor
timestamp: September 19, 2022, 09:01:49 pm
content: Yeah, I thought you basically had to order TO220F, or use silpads, unless its TRIAC as mentioned.They even show the D2PAK and the TO262 as tab connected, so just the TO220 being different would be kinda odd.
Video: 8-Bit Guy,  EV Roadtrip, Vintage Computer Festival, and Moonbase Repair  - Page 1
Forum section: electronics / general

author: Ed.Kloonk
author_rank: Super Contributor
timestamp: September 18, 2022, 06:34:37 am
content: Something for everyone.

author: MikeK
author_rank: Super Contributor
timestamp: September 18, 2022, 07:15:18 pm
content: Dang, I wish I had known about the Vintage Computer Festival...I would have gone.
Driving circuit for piezo - Page 1
Forum section: electronics / general

author: luoxx416
author_rank: Newbie
timestamp: September 14, 2022, 05:32:51 pm
content: Hi everyone,I'm trying to build a circuit for driving piezo element at high power. The circuit diagram is attached. The main components in the circuit are a gate driver(TC4422), a power MOSFET(IRL520) and a piezo which should resonant at 342kHz based on the spec sheet.The input digital signal is 5V square wav, the Vcc = 5V and VDD = 15V for testing.I measured the signals using an oscilloscope.CH1(Orange): Directly from the signal generatorCH2(Blue): Output from gate driverCH3(Purple): VDS from MOSFET with/without piezoF0052TEK is the one without the piezo element. The output from MOSFET looked nice.When I connected piezo to the MOSFET, the signal became worse. I am trying to understand why it happened.F0053TEK is the one with piezo element and the driving frequency is ~341 kHz.F0054TEK is the one with piezo element and the driving frequency is ~342 kHz.The output signal changed with the frequency. It looked better when driving frequency is closer to resonant frequency. My guess is the piezo has inductive and capacitive components when it’s not at resonance. That will cause the signals became less square wave like. Am I understanding this correctly?Thanks for the help!

author: SiliconWizard
author_rank: Super Contributor
timestamp: September 14, 2022, 07:57:07 pm
content: https://www.efunda.com/materials/piezo/electronics/elec_equiv_circuit.cfm
What were typical white dyes/pigments for lacquer in the 1950s? - Page 1
Forum section: electronics / general

author: Deactivated-1
author_rank: Frequent Contributor
timestamp: September 13, 2022, 04:41:50 pm
content: Excuse me posting a non-electronics thread in an EE forum, but I think most electronics projects would require paint at some point. And I could call it an electronics topic thread by saying "conductive dyes for better EMI shielding?"anyway, does anyone know what were typical white pigments/dyes used for white lacquer, specifically automotive nitrocellulose lacquer.my first thought was lead carbonate, but was it used for lacquers too? not just oil paints?

author: SeanB
author_rank: Super Contributor
timestamp: September 13, 2022, 07:31:30 pm
content: Yes you used lead carbonate, though more modern ones use titanium dioxide instead, as it is a lot less toxic, and more reflective as well. You just have to use a lead paint tester on the old paint to see just how much lead is in it.

author: rdl
author_rank: Super Contributor
timestamp: September 14, 2022, 11:48:32 am
content: Titanium Dioxide didn't really see widespread use until the toxicity of lead became better known, probably because of cost. So up until the 1960s or so, anything that's painted white might still have used lead carbonate as the pigment. Not everything needs automotive grade paint.
Let's say we have a stellerator outputting a steady 200 GW of electrical power. - Page 1
Forum section: electronics / general

author: cheater
author_rank: Regular Contributor
timestamp: September 12, 2022, 09:38:43 am
content: Let's say we have a stellerator outputting a steady 200 GW of electrical power. If someone dropped a conventional bomb / explosive / shell on it that was just enough to breach plasma containment, how much energy would be released, and what would the aftermath of this be? Assume a worst case scenario. Additionally, will any dangerous chemicals be released into the atmosphere?I'm trying to compare this to a similar scenario in a typical nuclear power plant. My guess is that the plasma will quickly dissipate and there will be no large radius of destruction beyond what a conventional bomb could do, and that no radiation or dangerous chemicals will be released - but I have no idea how to even approach this sort of question.PS I hope it's OK that I didn't put this in the renewable energy sub-forum, somehow I feel that wouldn't have been the best place for that sort of question.

author: tom66
author_rank: Super Contributor
timestamp: September 12, 2022, 10:01:03 am
content: Well, stellarators/tokamaks are "barely" stable with the building intact!! And 200GW implies a seriously massive reactor building.So assume the stellerator collapses from 200 GW to zero within five seconds then the energy released would be about 500 GJ, assuming a linear decrease in output power. That is roughly 100 tonnes of TNT or about 20x less than the explosion in Beirut in Aug 2020.I suspect you would need a lot more explosive power to break containment in the first place.A bigger risk might be the leakage of all the heavy water, which is toxic to most lifeforms in high enough doses, not sure if studies have been done on long term contamination of environments with that.
74LVCV2G66 abnormal charge injection value - Page 1
Forum section: electronics / general

author: MasterT
author_rank: Frequent Contributor
timestamp: September 11, 2022, 11:21:16 pm
content: https://www.nexperia.com/products/analog-logic-ics/analog/analog-switches/series/74LVCV2G66.htmlDShttps://assets.nexperia.com/documents/data-sheet/74LVCV2G66.pdfpage 11 says <0.003 pC, likely a typo. Can't get tech support from nexperia as a hobbyist.What do you think?

author: WattsThat
author_rank: Frequent Contributor
timestamp: September 12, 2022, 01:13:22 am
content: Cannot speak to your question from a position of actual experience but I found this on AD’s website:NOTE: Charge injection is usually specified on the data sheet under these matched conditions, i.e., VSOURCE = 0 V. Under these conditions,the charge injection of most switches is usually quite good in the order of 2 to 3 pC max. However the charge injection will increase for other values of VSOURCE, to an extent depending on the individual switch. Many data sheets will show a graph of charge injection as a function of Source voltage.My swag: Given the NXP part isn’t a specialized exotic switch, comparing it to switches that have the charge injection specified leads me to believe the datasheet units should have been nC rather than pC.

author: SiliconWizard
author_rank: Super Contributor
timestamp: September 12, 2022, 01:44:36 am
content: Their 74LVC2G66 datasheet states 2-3 pC:https://www.nexperia.com/products/analog-logic-ics/analog/analog-switches/series/74LVC2G66.htmlNot quite sure about the internal differences of the *74LVCV2G66* (it's supposed to be "Overvoltage tolerant"), but it does look like a typo here indeed. 2-3 fC? Yeah sure.
RCA CA3018 unused transistors - Page 1
Forum section: electronics / general

author: golden_labels
author_rank: Super Contributor
timestamp: September 04, 2022, 09:36:48 pm
content: Adie photo of RCA CA3018from Zeptobars shows two unconnected transistors. Anyone knows what’s the story behind them? The chip is a pair of transistors and a darlington pair on one die:RCA CA3018 datasheet.At first I was thinking about producing more transistors per chip to accomodate for manufacturing errors and use only good ones. But the metal layer offers no flexibility.CA3018 die shotfrom another source shows exactly the same layout too.A different metal layer could be used for another model, with the transistors themselves reused. But 11 out of 12 pins in theTO-101 packageare used, leaving no space for more connections. Was that for an alternative chip, but with a completely different configuration? CA3036 would require only 4 transistors (2 per each darlington pair).--- edit:After writing that post I found CA3026, which contains two independent differential pairs, each consisting of three NPN transistor. The part has the same absolute maximum ratings, the same package, is designed to operate in the same frequency range and was produced in the same period. Could be a candidate for silicon reuse.

author: golden_labels
author_rank: Super Contributor
timestamp: September 11, 2022, 01:41:24 am
content: Zeptobars answered the question by posting aCA3019 die photo.However, the description seems wrong.CA3019 is supposed to a six diode arrayand the die clearly shows diodes in the expected configuration. This is even more interesting than I thought, as that means they re-used BJTs as diodes, which is also clearly shown in Fig. 2!
Interesting video on ferromagnetic behavior - Page 1
Forum section: electronics / general

author: WattsThat
author_rank: Frequent Contributor
timestamp: September 10, 2022, 04:07:21 am
content: It starts out as a video about induction heating and then moves into magnetic domains.

author: KE5FX
author_rank: Super Contributor
timestamp: September 10, 2022, 06:07:35 am
content: I'm surprised I've never heard of this channel before. Super impressed with the first couple of videos chosen more or less randomly.

author: PartialDischarge
author_rank: Super Contributor
timestamp: September 10, 2022, 06:12:50 am
content: Quote from: KE5FX on September 10, 2022, 06:07:35 amWhat I like about his videos are that they are relatively short and goes straight to the point with curious effects on physical ,chemical, electronic effects.

author: RoGeorge
author_rank: Super Contributor
timestamp: September 10, 2022, 06:36:09 am
content: Quote from: KE5FX on September 10, 2022, 06:07:35 amYou never heard of "The Action Lab" channel because you don't visit the "Fun for nerds" topic, that's why!https://www.eevblog.com/forum/chat/fun-for-nerds/msg3613091/#msg3613091Indeed, one of he most interesting science experiments channels on YouTube.To me, "The Action Lab" is the best YouTube channel for physics experiments.

author: mag_therm
author_rank: Frequent Contributor
timestamp: September 10, 2022, 03:24:56 pm
content: Re the video in o.p. on magnetic effects and induction heating.The opening statements and the explanation of the "friction" of Barkhausen effect being a cause of induction heating of cold steel( penny demo etc) is about 97% incorrect.The effects described in the video were quantified by Charles Steinmetz before 1900 and his law , with minor additions, is still accurate and used today to measure losses in magnetic cores.These losses do occur during induction heating of steel bars and pennies, but the dominant effect is Joule heating by eddy currents distributed with high intensity at surface of metal due to the skin effect.To quantify the power losses in Watt/kilogram of typical annealed automotive grade steel:1) Magnetic losses by Steinmetz: 2.2 Watt/kg at 60 Hz and 110 Watt/kg at 3000 HzRef: Bozorth page 514, hysteresis loss for various steels and magnetic materials.2) Joule heating of cold steel by eddy current (induction) : 3800 Watt/kgRef: Peak power density in the cold steel from a typical induction heating inverter rated 4000 kW producing about 10000 ~ 12000 kg of steel per Hour.The author of the video failed to inform of the basics, failed to check the above comparison and is stating that he is demonstrating an effect when it is only about 2.9 % of the actual effect.
Radio Shack Pocket Repeat - Page 1
Forum section: electronics / general

author: muffenme
author_rank: Contributor
timestamp: March 03, 2017, 07:28:26 pm
content: I like to change 3 of 4 red leds with yellow, green and blue of the same size. Is it possible to do, the leds don't need to be bright, just lit. Do I need to change any resistor. Thanks

author: james_s
author_rank: Super Contributor
timestamp: March 03, 2017, 07:53:41 pm
content: Depends on what voltage is available, red LEDs typically have the lowest forward drop, blue are one of the highest, some are close to 3V. You will probably need to change the resistors to get consistent brightness between colors but you might not care. Try it and see what happens. You can always put the original LEDs back if it doesn't work well.

author: Rick Law
author_rank: Super Contributor
timestamp: March 05, 2017, 06:27:47 pm
content: And... if brightness equality is important, it is probably easiest if you using one of those 25 turn trim pots to help with determining the resistance.I used to do it mathematically to give different color led the same current. But, same current != same brightness.Now I use a trimpot to get them to appear equally bright, then use a DMM to find out what resistance it is. Then I do some quick calculation to make sure that is within the LED's spec. If all is well, I find a fix resistor closest to the measured value and then solder it in.

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: March 06, 2017, 12:16:50 am
content: Haven't seen one of these in a long time. I used to play with one as a kid when it was rainy at the summer place. There wasn't much else to do in the pre-net days, except for the two local TV channels on the BW TV...

author: muffenme
author_rank: Contributor
timestamp: September 04, 2022, 02:56:01 am
content: I did replaced the LED and it did work. My unit now has the right color LEDs instead of all just red LEDs.

author: james_s
author_rank: Super Contributor
timestamp: September 04, 2022, 06:41:48 pm
content: I'd never heard of the Pocket Repeat but it looks like a clone of Simon. I have both an original full sized and a pocket Simon, I like that they use incandescent lamps.

author: ebastler
author_rank: Super Contributor
timestamp: September 07, 2022, 05:29:27 am
content: Quote from: muffenme on September 04, 2022, 02:56:01 amIt took you a while to replace those LEDs, but thanks for the follow-up post!
AI generated imagery getting absurdly good - Page 1
Forum section: electronics / general

author: daqq
author_rank: Super Contributor
timestamp: September 08, 2022, 11:38:15 am
content: Wow... been playing around with it, a lot of the results are garbage, but some are genuinely impressive!Not mine:https://creator.nightcafe.studio/creation/m9CvUiY9qLph6GREPG1g

author: Ranayna
author_rank: Super Contributor
timestamp: September 08, 2022, 03:53:22 pm
content: Overall that looks nice. But those eyes...All pictures of people or animals i have seen from any of these image AIs have crappy eyes. It almost looks deliberately bad.

author: fourfathom
author_rank: Super Contributor
timestamp: September 08, 2022, 04:13:33 pm
content: Eyes are the windows to the soul. AI has no soul.Seriously, this stuff has come a long way since the depths of the Uncanny Valley.

author: SiliconWizard
author_rank: Super Contributor
timestamp: September 08, 2022, 06:45:55 pm
content: Yeah, nothing that a skilled human can't do with 3D software and raytracing. Actually, they would do it better.What's more both uncanny and concerning IMO is the ability to generate those "deep fakes", looking like real people and having them do or say whatever. And while it can be spotted with a close look, it's getting harder and harder to spot for the vast majority of people.

author: daqq
author_rank: Super Contributor
timestamp: September 08, 2022, 08:00:19 pm
content: Quote from: SiliconWizard on September 08, 2022, 06:45:55 pmWhich was never the point. I find it impressive that just by inputing some text and playing around with the results I can have in seconds/minutes a very good image usable for a bunch of things.
How is Infineon doing for chip making lately? - Page 1
Forum section: electronics / general

author: Faringdon
author_rank: Super Contributor
timestamp: September 07, 2022, 01:23:31 pm
content: Hi,How are stocks at Infineon?I just designed voltage mode half bridge with their superb 2ED21… series of superb bootstrap drivers which mitigate negative bridge transitions and all the other ills of bootstrapping….but they seem to be hardly in stock anywhere…think I will change back to using gate drive txformer, lest anyone can tell me different?

author: Wolfram
author_rank: Frequent Contributor
timestamp: September 07, 2022, 09:38:37 pm
content: About as good or bad as anybody else making isolated gate drivers or chips in general. Similar parts from Silabs/Skyworks, TI and AD have also been mostly unavailable for the last year plus. That favors transformers for gate drive, where they can be used.
Bianchi Vento 605 vs 606 (1995) & looking for Use and Maintenance Manual - Page 1
Forum section: electronics / general

author: DiTBho
author_rank: Super Contributor
timestamp: September 08, 2022, 12:10:28 am
content: hiYesterday I found an abandoned frame. It's aBianchi Vento 606, similar to my oldVento 605, but I cannot understand the differences (if any?).Both steel road 90s bicycles.I am also looking for theUse and Maintenance Manualbecause there are some parts (like the headset) that look a bit weird and I don't know how to properly disassembly and replace.Does anyone happen to have a pdf of the Use and Maintenance Manual for those old Bianchi models?Thanks

author: DiTBho
author_rank: Super Contributor
timestamp: September 09, 2022, 08:24:03 am
content: Comparing the headset of the 605 and 606 to what I see on 2000s bicycle well ...On 2000s bicycle headsets you can unscrew the lock nut and read the type of threadOn 1998 bicycle headsets your can unscrew the lock nut and read the type of threadOn 1992-1995 bicycle headsets unscrew the lock nut and ... you read nothing, there is no information

author: DiTBho
author_rank: Super Contributor
timestamp: September 09, 2022, 08:33:19 am
content: also you don't know if the headtube is of 30, 32, or 34 mm, and you cannot easily deduce it.This information is written on the top cover of the external cup of the headset group.

author: wn1fju
author_rank: Frequent Contributor
timestamp: September 10, 2022, 12:29:34 pm
content: You might try asking this question on some of the bicycle-specific internet forums such as bikeforums.net or roadbikereview.com.I found an old copy of the Barnett Bicycle manual and have attached a picture of their page on headset dimensions.If the headset still works without binding or feeling notches at different steering angles, I would simply remove the stem, unscrew the headset, pull out the fork, clean and re-grease the bearings, then reassemble. Providing you have the tools and expertise to do this successfully. The chances of finding a suitable replacement among modern stock is pretty low. Besides, nowadays, everybody is using threadless headsets which are completely different.
Eureka Lightspeed 2-in-1 Cordless Stick Vacuum Filter - Page 1
Forum section: electronics / general

author: dvd4me
author_rank: Regular Contributor
timestamp: September 06, 2022, 12:45:18 am
content: Hello,I post this here so others can find the filter part replacement without too much guess work.I have searched for the original NEC160C part and it is " out of stock".Then on other online parts sellers and eBay the price is just a joke, too much.Finally, I found an European modelGrundig Filter 23620 For Grundig VCH9629 VCH9630 VCH9631 VCH9632.It is identical with the Eureka one. Job done once the information is figured out.These I got from Ali are around 5$ plus shipping, very affordable and fit perfectly. Search for the Grundig model.Cheers
Nanotech Video Vinyl: The Remarkable CED - Page 1
Forum section: electronics / general

author: BrianHG
author_rank: Super Contributor
timestamp: September 02, 2022, 11:14:43 pm
content: Yes, RCA successfully recorded video on Vinyl. 1 full hour per side. See microscopic images here:

author: PlainName
author_rank: Super Contributor
timestamp: September 03, 2022, 04:22:55 pm
content: !If anyone else had come up with that, thunderf00t would be crowing about how it couldn't possibly work.

author: BrianHG
author_rank: Super Contributor
timestamp: September 03, 2022, 07:37:08 pm
content: Quote from: dunkemhigh on September 03, 2022, 04:22:55 pmLOL...
Am I polluting our environment? - Page 1
Forum section: electronics / general

author: dastructhm
author_rank: Contributor
timestamp: September 06, 2022, 04:54:50 am
content: I use lead(40%) solder to solder my boards. My boards' pads contain lead. My solder paste may contain lead too. I wash them all with ethanol. I threw away bad boards in the dumpster.I never actually thought about it, when it comes it environment protection, until a few days ago: Am I polluting the environment? To be specific, our water system in the drain and our soil? It sounds scary...

author: ataradov
author_rank: Super Contributor
timestamp: September 06, 2022, 05:09:22 am
content: You are. Almost everything you do as a living being pollutes the environment. What you do with the solder is minuscule compared to other stuff. You probably cause more tangible damage by eating a burger.With ethanol - it is not the best idea to drain it into the sewer. It is technically prohibited in any concentration. The best way of home disposal is letting it evaporate in a well ventilated environment. There is no reason to use so much of it for the PCB stuff that it becomes an issue. Most of the stuff evaporates in the process of washing anyway.

author: AndyBeez
author_rank: Frequent Contributor
timestamp: September 06, 2022, 08:32:19 am
content: Throw your bad boards into the E-waste bin at your local city or council tip. In theory they will pass the E-waste to a facility that extracts the dangerous chemicals. In reality, the E-waste facility may be a scam business that's shipping non ferrous parts to a burning rubbish heap in central Africa - but at least you made the effort to protect your local environment.RoHS in Euroland :https://en.m.wikipedia.org/wiki/Restriction_of_Hazardous_Substances_Directive
Automotive ECE R10 compliance - Page 1
Forum section: electronics / general

author: ithecoe
author_rank: Newbie
timestamp: September 01, 2022, 07:14:53 pm
content: Hi,I'm working on an automotive prototype project with local vehicle/trailer upgrade shop. The main function of the module would be driving some lights (totaling up to 10 A), supplied via vehicle battery (12 V) and module is connected to the vehicle harness. If this turns out to be a viable product it needs to be certified according to ECE R10 for E-marking (https://ec.europa.eu/docsroom/documents/16513/attachments/1/translations/en/renditions/native).So, before I dive into the design, I figured I should see the regulatory requirements. There are many tests for emissions and immunity (conducted, transient, radiated, surges etc.) under R10. I couldn’t find any requirements/guidelines for part qualifications (AEC…) or quality grade (automotive etc.).Is this area under different directive or are these specific requirements from buyers?Is it mandatory to use automotive qualified parts for module to pass ECE R10 or is that up to designer? I am looking into using STM32F0x2 (temp range -40 to +85 °C or -40 to +105 °C, but not AEC qualified. Is that a dealbreaker from the start?I am well aware that there should be some additional protection circuit with LDO for dealing with disturbances for good performance.The high side drivers I am looking into are from STM VNQ series and Infineon smart power switches. Both automotive qualified but with different level of immunity to disturbances. This topic I must study a bit more.How is that with passive components, is automotive grade mandatory?In todays world with supply chain issues and long lead times, is it possible to change some elements (with similar characteristics, different suppliers etc.) without invalidating certification?- Are there any additional tests required like exposing the module to mechanical vibrations, temperature (performance at 60C, 70C ambient for example)? ECE R10 is for electric but properties change under different conditions and ofc time.- Any tests for module connectors (strain)?- Is module housing/caase under any regulation (material type/properties)?- Does a MCU software need to comply to any regulation (or the programmer)?I suppose there can be many tests performed or requirements fulfilled if the buyer requests it but for now, I am focused on ECE R10 and proper performance in intended environment to get started.As you can see, I have many questions manly just to gauge what does the undertaking of such project entails.If someone could point me in the right direction I would be very grateful.Thanks!
Anyone with a netcomponents.com account or similar? - Page 1
Forum section: electronics / general

author: adidor
author_rank: Newbie
timestamp: September 01, 2022, 04:07:52 pm
content: If so any chance you could please give me a reliable lead for this part?:https://eu.mouser.com/ProductDetail/Nexperia/74LVC1G125GW125?qs=me8TqzrmIYXtmz2PPTYwGg%3D%3DLead time is 77 weeks on Mouser and I need 210 of them 😩
Low cost products and the chip shortages  - Page 1
Forum section: electronics / general

author: Jester
author_rank: Frequent Contributor
timestamp: August 30, 2022, 12:48:23 pm
content: Most of my career was spent developing low volume high cost products that had very large markups, so when a component became difficult to source, we always had the option of going to a broker, if we normally paid $10 for the part, even if we were forced to pay $100, it was not a big deal when the product used one such component and sold for say $50,000At the other end of the spectrum there are companies producing low cost products with perhaps one $5 microcontroller with total (pre Covid) BOM cost of perhaps $20, and now the brokers want $50 for that one microcontroller. The increased cost of that one device might equate to the entire profit for a low cost device.So for those in that situation what are you doing, marking up the price or stopping production?Redesign seems like a game of whack-a-mole

author: SiliconWizard
author_rank: Super Contributor
timestamp: August 30, 2022, 09:29:10 pm
content: High volume low cost products for a western company is kind of a suicidal business model these days anyway.Now for the the chinese companies that can actually profit from this business model, I'm sure they have it a bit easier to get ahold of semiconductors than we do. So... Just a thought?
Mystery connector symbol - Page 1
Forum section: electronics / general

author: Gusbert
author_rank: Newbie
timestamp: August 30, 2022, 01:35:33 pm
content: I have a 24-way industrial connector which has this manufacturer's symbol on it:Does anyone know who this is?

author: Brumby
author_rank: Unknown
timestamp: August 30, 2022, 01:39:14 pm
content: Weidmüller is my guess.https://www.weidmueller.com/int/index.jsp

author: Gusbert
author_rank: Newbie
timestamp: August 30, 2022, 02:02:43 pm
content: Thanks! Of course, if you rotate the symbol you see a W over an M.
PLCNow HMI/SCADA software - Page 1
Forum section: electronics / general

author: Clinton
author_rank: Newbie
timestamp: August 29, 2022, 03:17:00 am
content: Has anyone ever heard of PLCNow? It's a SCADA/HMI software running on a windows machine. Google hasn't come up with the goods, so I thought I'd try my luck here. I imagine there's a few automation engineers on the forum..

author: JohanH
author_rank: Frequent Contributor
timestamp: August 29, 2022, 07:47:56 am
content: No. Whats the issue/question? Looks like some basic control or demo software supplied with some Grundfos pumps? Even Grundfos is spelled wrong in the button in the center... Any date or info in Help menu? Could also be custom in-house software.

author: Clinton
author_rank: Newbie
timestamp: August 30, 2022, 02:17:10 am
content: The question is really just "Has anyone ever came across this PLCNow software before? Who published it etc?"This photo was taken by a colleague who was onsite (over 400km away) sorting out some mechanical issues and the subject of their SCADA system came up.I was hoping to have a little more information before approaching the owners is all, so just curious if anyone has ever seen PLCNow software before.
Help locating UK/EU supplier of dual axial Vishay caps - Page 1
Forum section: electronics / general

author: cowasaki
author_rank: Frequent Contributor
timestamp: September 01, 2022, 08:39:59 pm
content: I'm attempting a repair on a HP 3582A audio spectrum analyser. The power supply is not giving the right voltages and showing a red LED on one of the boards. I have removed all seven of the power boards and noted the capacitors and having desoldered one end of a few of them found that they are well out of spec. The caps are as follows:1 – A 2xB2 – C 2xD 2xE3 – G F4 – G H5 – G H6 – G H7 – G HA = 1 x 1700uF/30 axial 59x21B = 2 x 300uF/40 axial 44x18C = 1 x 45uF/250 axial 56x17D = 2 x 350MF/16 axial 29x10E = 2 x 50uF/50 axial 24x10F = 1 x 1000MFD/12 axialG = 4 x 470uF/25V DUAL axial 43 x 12.5H = 5 x 47uF /100V DUAL axial 43 x 12.5OK so this should not be difficult (except on the wallet). All the caps are axial type with G & H being DUAL axial and it is these caps that I just cannot find ANYWHERE. I only know of one supplier for any type of dual axial caps and they only sell the type that are normally used on valve amplifiers.Unfortunately there isn't really enough space to fit two single axial caps into the space even with modern smaller caps. If I have no choice I would have to but it will not be as tidy as it should be.

author: coppercone2
author_rank: Super Contributor
timestamp: September 02, 2022, 01:37:44 am
content: Yes I dislike that you can't get dual axial caps either, that is quite a interesting design decision you used to be able to make.

author: cowasaki
author_rank: Frequent Contributor
timestamp: September 02, 2022, 07:01:30 am
content: Absolutely. The piece of equipment I am repairing deserves to be repaired using top quality components as per the original design. I really don’t want to have to cobble in a bodge using two caps where one should go. It’s probably possible but each of the seven power boards slides in and there isn’t even much space.

author: coppercone2
author_rank: Super Contributor
timestamp: September 02, 2022, 07:48:47 am
content: the repair forum had the same problem a while back with a old HP power supply that had a oil filled tapped capacitor. The modern solution is downright ugly in comparison
Midjourney suggested renderings of Fluke 87 V multimeter, entering atmosphere on - Page 1
Forum section: electronics / general

author: nixxon
author_rank: Frequent Contributor
timestamp: August 18, 2022, 09:18:46 pm
content: The AI rendering graphics technology is pretty awesome. I rendered 4 images by typing the command "/imagine Fluke 87 V multimeter, entering atmosphere on earth from space at high speed, red hot mustache, realistic". The result was not at all what I expected. Here are the 4 thumbnail images that were created by Midjourney on Discord in a few seconds. The thumbnails serve as a starting point for further development and playing around.What topic could possibly be better than "Test Equipment" for this post?

author: nixxon
author_rank: Frequent Contributor
timestamp: August 18, 2022, 09:24:03 pm
content: The same query without the red hot mustache:

author: nixxon
author_rank: Frequent Contributor
timestamp: August 18, 2022, 09:32:47 pm
content: This AI has no clue what a Fluke 87 V is. Here is the result of the query for "Fluke 87 V multimeter close-up, falling down to earth, realistic"

author: Black Phoenix
author_rank: Super Contributor
timestamp: August 27, 2022, 01:35:56 am
content: Quote from: nixxon on August 18, 2022, 09:32:47 pmWell at least it knows it is yellow...

author: Bud
author_rank: Super Contributor
timestamp: August 27, 2022, 02:32:07 am
content: Well, in light of the latest EEVBlog video, try "Fluke multimeter leaking Energizer batteries realistic"

author: Black Phoenix
author_rank: Super Contributor
timestamp: August 27, 2022, 04:05:29 am
content: Yeah Bud, that one was a big one. Heck even the plastic broken down. I think it was because of the seal around the door cover who kept the liquid and vapours inside, breaking down the plastics.I had such happen to my 54-II but since it is not a totally hermetic one the damage was contained in the back cover and a spot on the MPU legs that was easy clean and reflown. The culpid in this case was Duracell Procell. And I has able to save the 289 before they started leaking (but they were already discolouring).

author: eugene
author_rank: Frequent Contributor
timestamp: August 27, 2022, 05:08:09 pm
content: Quote from: nixxon on August 18, 2022, 09:32:47 pmI'd guess that only a tiny percentage of RI (Real Intelligence) knows what a Fluke 87 V is. Why pick on AI?

author: bdunham7
author_rank: Super Contributor
timestamp: August 27, 2022, 05:24:30 pm
content: Quote from: eugene on August 27, 2022, 05:08:09 pmThe AI could google it instead of going on an acid trip.

author: SiliconWizard
author_rank: Super Contributor
timestamp: August 27, 2022, 07:14:46 pm
content: Quote from: eugene on August 27, 2022, 05:08:09 pmYeah, why pick on AI. This is discriminatory. AI is going to feel oppressed. Should be laws about that!