hybridfree/eevblog-posts huggingface dataset:
Which supplier/manufacturer are the most friendly/supportive for small projects? - Page 1
Forum section: electronics / projects

author: kuon
author_rank: Regular Contributor
timestamp: February 21, 2021, 09:44:59 pm
content: I am a solo engineer in our startup, and I do everything from PCB design to firmware coding.I sometimes have questions or need support about components, and as I don't have a team of fellow engineers to make a meeting I try to ask the manufacturer for support (or I come here).Now I was working on a capacitive sensor, and I had very different experience with manufacturers.- Cypress was very helpful and nearly drew the PCB for me, they also offered to review my design- ON semi which had a friendly email support and answered my questions- analog, which answered my questions, but only pointing me to datasheets and app notes I already read- Rhom, which just told me they did not support "small customers"This lead me to wonder what your general experience was.For example, the other day, I read that TI was using DMCA to take down datasheets from some open website. As an open source supporter and contributor, it really disturbed me. And now I do not use TI products in any of my design.So, to summarize, for each manufacturer, I would really love your stories and "ranking" on the following points:- How open are they with "makers"? Do they encourage hacking, support open source?- Do they have good support, even for "small customers"?- Are they accessible? (public forum, staff fluent in english...)- Do they have plenty of application notes and example? When I pick a component, I really like to have an app note with a reference design, with resistors and cap values... Also, notes about gotcha, because when you are working solo on a project, it is harder to think of everything, so if the app note mentions "put an EMC filter if your signal pin is longer that XXX, here is an example schematic"...

author: wizard69
author_rank: Super Contributor
timestamp: February 22, 2021, 01:36:58 am
content: I'm not sure what to say here. Any engagement can lead to the old {what can we do to get rid of the mother in law} syndrome. In other words it is easy to out stay your welcome. So in this context you may get good support today but you can easily causes a shift in friendliness by excessive interaction. That is support departments have many customers to handle and they are not likely to spend a lot of time on somebody that doesn't have a product in mind. Perhaps more importantly they will not be happy to support a person not putting in the effort.When I read this article the first thing that came to mind is that you want all the engineering done for you. How willing a support engineer is will be to do this varies widely.In any event I'd be interested to hear what is up with TI from your perspective. Last I knew there was nothing specifically bad going on with TI and access to their documentation.

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: February 22, 2021, 01:42:12 am
content: The magic term is EAU: estimated annual usage. If you're below what they consider worthwhile, you're on your own.
which transfer function of RC servo i should belive ? - Page 1
Forum section: electronics / projects

author: ammjy
author_rank: Regular Contributor
timestamp: April 11, 2018, 07:42:33 am
content: Hello ! Thanks you for click !!in Matlab R2017b, with System Identification toolbox, i got transfer fucntion of RC servo motor.im using Arduino Due now. i gave signal 0 to 90 degree.and i measured step response from potentiometer included in RC servo for feedback.when 0 degree, voltage level is almost 0.3 V from potentiometer.when 90 degree, voltage level is almost 1.41 V from potentiometer.from measured excel data in workspace in matlab, i deleted value as much as 0.3 for zero matching when degree is 0.after save input and output.in System identification toolbox, i loaded input, output data. (when i setting input and output, i setted starting time 0, sample time 1)then, with process model, i got transfer function with this form.K*exp(-Td*s)------------------1+Tp1*si repeated this process few time for do compare results.and i stucked. because, i don't have idea. which TF i should belive....Please, see the picture what i uploaded...Please, give me advise, let me know..this is my code in matlab. (time setting is fine ?)------------------------------------------------------------------------clc; clear all; close all; %Reset alla=arduino('COM4','Due','Libraries','Servo'); %Set Arduinio boardai_pin='A6'; %Set Analog pin for ADC from potentiometer of RC Servos = servo(a, 'D7');tic; %Set stopwatch timeri=0;while (toc<4)i=i+1;t(i)=toc;out(i)=readVoltage(a,ai_pin); %Already adc voltages calculatedfigure(1)plot(t,out,'r');pause(0.05);if toc < 2 %if toc cound is less then 2, give 0 degree signal. if not, give 90 degree signal.in(i) = 0;writePosition(s, in(i));elsein(i) = 0.5;writePosition(s, in(i));endend------------------------------------------------------------------------
Which type of LED is used here ? - Page 1
Forum section: electronics / projects

author: maxpayne
author_rank: Regular Contributor
timestamp: April 13, 2016, 06:25:06 am
content: I want to know the type of the LEDs used inside here for flashing. These LEDs are flashed in the full sunlight and viewable by anyone easily.Thanks in advance.

author: maxpayne
author_rank: Regular Contributor
timestamp: April 13, 2016, 06:34:29 am
content: Quote from: blueskull on April 13, 2016, 06:32:47 amWhat can be the lumen and current rating of these LEDs ? Any probable link ?

author: maxpayne
author_rank: Regular Contributor
timestamp: April 13, 2016, 08:08:30 am
content: Quote from: blueskull on April 13, 2016, 06:37:56 amthat means the mcd range should be from 25000 to 45000 for under the sun flashing. right ?
Which voltage reference to get (Aliexpress) - Page 1
Forum section: electronics / projects

author: drummerdimitri
author_rank: Frequent Contributor
timestamp: March 20, 2018, 10:22:27 am
content: I'd like to calibrate some cheap old Radioshack DMMs since they have drifted from my Fluke 289's measurments and would like to get the best voltage reference that I can calibrate them against.Will only consider purchasing on Aliexpress but there seems to be lots of models with slightly different AD584 chips.Which one should I go for?

author: The Soulman
author_rank: Super Contributor
timestamp: March 20, 2018, 10:55:28 am
content: If you trust your fluke 289, you could use that as a reference.Assuming the other meters are 2000 count, you could measure a 1,5V battery simultaneously with the flukeand a cheapo, adjust the cheapo to match the reading of the fluke.For resistance (usually not adjustable) you could use generic resistors and measure them with the fluke, write down the values,and remeasure whit the cheapo, on lower resistance values contact resistance will play a role so be aware of that.How many trimpots are in these cheapo meters?

author: drummerdimitri
author_rank: Frequent Contributor
timestamp: March 20, 2018, 11:35:11 am
content: Quote from: The Soulman on March 20, 2018, 10:55:28 amProblem is I've had my fluke for about 6 years now and never had it calibrated so I am not sure how accurate it is reading.The cheapos have two trim pots one for ac v and one for dc v.

author: Abbas
author_rank: Contributor
timestamp: March 20, 2018, 02:15:53 pm
content: The best I use for voltage reference in calibrating el cheapo DMMs is by using a L7805 Voltage regulator powered via a 9V battery, and I measure its output voltage using my Fluke 87V and the Sanwa CD800a. Then by adjusting the trimpot inside the DMMs, I set its reading to the reading/average between those two multimeters.For resistance calibration, I use 3 different precision resistors(1k, 10k and 20k), each rated with 0.001% and 0.005% tolerance respectively. Got them all from Vishay(I don't remember their part number, I just know they are those with oil inside for temperature stabilization and etc)
Which was first ECC82 or 12AU7 - Page 1
Forum section: electronics / projects

author: Brasto
author_rank: Contributor
timestamp: December 20, 2018, 08:23:20 am
content: Back then in the 50's a new series of electron tubes appeared on the market using the NOVAL type socket.Identical pin-to-pin equivalents were found in the USA and European products only difference was their marking e.g. ECC82 or 12AU7.Question:Being an old Dutchman I like to belief that Philips/Mullard was the original inventer/designer of this double triode which was at a later date coproduced by various USA companies.Who holds the patent (if any) on e.g ECC82 or 12AU7?Were 12AU7 produced on same assembly lines as ECC82 but only marked differently?Who has designed the noval pin base?
Which way does the R10 series DS show relay pin-out - from underneath? - Page 1
Forum section: electronics / projects

author: 741
author_rank: Frequent Contributor
timestamp: January 05, 2024, 01:04:17 pm
content: I'm looking at a TT/Potter & Brumfield DS for their R10 relays. I'm unsure which direction the contact view is (I think it will be as seen from underneath)https://www.digikey.co.uk/en/products/detail/te-connectivity-potter-brumfield-relays/R10-E1Y4-V2-5K/44940?s=N4IgTCBcDaIEoEYAMBaAoggmgFhQNTADoBWAaRAF0BfIA(I need to design a Kicad footprint for the matching PCB-mount socket)[The other thing I nee to find out is an equivalent for a relay shown on an old parts list as "Pye 2CT/210/A relay". I think it'll be a 50V coil].
White Led strip for a Lightbox(board) - Page 1
Forum section: electronics / projects

author: Arcamax
author_rank: Regular Contributor
timestamp: May 05, 2015, 03:03:59 pm
content: Should i use a 5050 warm white or a pure white strip. Cant decide 100%http://www.ebay.ca/itm/371305992754?_trksid=p2055119.m1438.l2649&var=640425017958&ssPageName=STRK%3AMEBIDX%3AITI want to use my clear acrylic i have laying around. I'll just scuff it up with course sandpaper to give it an etched effect so it shines/glows nicely.

author: ajb
author_rank: Super Contributor
timestamp: May 05, 2015, 05:11:02 pm
content: . . .depends on if you want it too be warm white or pure white? It's really an aesthetic judgement.

author: georges80
author_rank: Frequent Contributor
timestamp: May 05, 2015, 05:52:30 pm
content: It is a subjective choice.Warm white is nice for general interior lighting since it is what we're used to coming from incandescent bulbs and candles...Cold white is 'clinical'...IMHO.cheers,george.

author: Zero999
author_rank: Super Contributor
timestamp: May 05, 2015, 06:12:14 pm
content: Where is it going to be used?

author: Arcamax
author_rank: Regular Contributor
timestamp: May 05, 2015, 06:52:22 pm
content: im making a light board to trace pictures with

author: Zero999
author_rank: Super Contributor
timestamp: May 05, 2015, 07:19:05 pm
content: Pure white is probably best then.

author: SL4P
author_rank: Super Contributor
timestamp: May 06, 2015, 04:16:29 am
content: Quote from: Hero999 on May 05, 2015, 07:19:05 pmIf you ever expect to use the light box for any colour evaluation - then definitely use the 'pure' white.The yellow 'warm' white, will challenge your eyes trying to match colours in disparate pieces of content..

author: georges80
author_rank: Frequent Contributor
timestamp: May 06, 2015, 04:41:19 am
content: "pure white" is hardly pure - wrt to LEDs. Check their spectrum... Besides, I have no idea what you would call "pure white".Basically there's a colour temperature binning for white LEDs and you can choose from a large range. The spectrum is still not broad band (lots of peaks).You can also use cold white and mix in amber LEDs as needed to shift the colour temperature to what is 'nice' for you.cheers,george.

author: miguelvp
author_rank: Super Contributor
timestamp: May 06, 2015, 04:55:29 am
content: Or you could use the back light of a monitor or a laptop without the LCD but keeping the diffusers.I don't think it ended up giving a lot of light, but enough for doing the job.But I bet is cheaper to purchase used X-Ray light boxes or even new ones from ebay.http://www.ebay.com/sch/i.html?_nkw=xray+light+boxEdit: or even cheaper, tracing light boxes from ebayhttp://www.ebay.com/sch/i.html?_nkw=tracing+light+box
Who does PCB panelization the best - Page 1
Forum section: electronics / projects

author: Cicada
author_rank: Regular Contributor
timestamp: September 14, 2023, 11:23:09 am
content: HiI plan to layout 3 or 4 PCBs very soon. My first PCBs in a long time. For the first time ever I plan to get my boards manufactured in the east.I want to minimise cost so I have two options:1. Send all the designs in at the same time and have them shipped together to me. I am not sure if it is possible with the online manufacturers.2. Panelize the designs myself, or use their services to do so and have a panel shipped back.I try to do this to save on the shipping cost.What is the best way to go about this?Which one of the big names are the easiest to use in this regard?Any advice, pointers and hard earned experiences are welcome.Thanks a lot.Cidada

author: wraper
author_rank: Unknown
timestamp: September 14, 2023, 11:33:13 am
content: Generally you don't want to panelize different designs into single panel for cost purposes if you're asking about that. It only increases the cost when ordering from inexpensive online services.QuoteWhy wouldn't they ship different designs in single package? Simply add multiple items to the cart and order. The cheapest and fastest service for most orders is JLCPCB.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: September 14, 2023, 11:38:28 am
content: Most of my experience is with JLCPCB -They will charge extra for multiple designs on one panel.Note that any difference at all counts as an extra design - I once got caught by this as I duplicated a PCB in a panel within my PCB software so parts had different silkecreen designators.The extra charge is per design, not per board.Suggest you compare costs in the online quote page of doing it as one mixed panel or seperate PCBs.Yes, multiple boards can be placed on one order and will ship together, saving a lot of shipping costIf panelisation is for production, always do it yourself as you know what your manufacturing constraints are.

author: DavidAlfa
author_rank: Super Contributor
timestamp: September 14, 2023, 11:42:56 am
content: You might sneak 2 different designs into a panel, I've done it lots of times, sometimes you get a message asking for an extra fee, cancel and try again.But more than than, it won't. I got $20-something extra free for combining 5 different designs, which were very simple breakout boards for testing some chips.I ended making different orders for each design, much cheaper, but I only needed few boards, now I have gazillions that can only contribute to e-waste.

author: Cicada
author_rank: Regular Contributor
timestamp: September 14, 2023, 12:28:54 pm
content: HiI think the posts from Wrapper and Mikeselectricstuff answers my questions. I will not panelize, I will order 3 seperate designs at the same time. So they will then ship them together.But please let the tips and info from other roll in.
Who here knows their magnets? - Page 1
Forum section: electronics / projects

author: cvanc
author_rank: Frequent Contributor
timestamp: March 06, 2025, 10:27:46 pm
content: Help me find something, folks? I've looked at several suppliers and it seems I want something rare - see photo.I need one pole on the outside and the other pole on the inside. Neodymium is preferred. If you know of a source please share and thanks in advance.

author: edavid
author_rank: Super Contributor
timestamp: March 06, 2025, 10:40:53 pm
content: Here is a source:https://supermagnetman.com/collections/neo-radial-rings
who is the current manufacturer of TA7642 AM radio transistor - Page 1
Forum section: electronics / projects

author: midnightvisions
author_rank: Contributor
timestamp: August 07, 2023, 12:56:29 pm
content: Hello,The TA7642 AM radio transistor seems to be being produced by somebody. Does anybody know who is the current producer?This page listed a Shenzen company, but clicking that link says the government has repossessed it.https://www.eevblog.com/forum/projects/misuse-of-a-ta7642-(mk484)/Thanks.
Who makes custom cables like this? (DC barrel plug) - Page 1
Forum section: electronics / projects

author: K3mHtH
author_rank: Regular Contributor
timestamp: December 04, 2019, 10:17:35 pm
content: I'm looking to have some (100pc) custom cables made that resemble this, with DC barrel connectors molded on to each end. I want to be able to specify length and type of connector (right angle, straight, etc.).Anyone have any direct experience getting anything like this made?

author: thm_w
author_rank: Super Contributor
timestamp: December 05, 2019, 01:16:20 am
content: https://www.alibaba.com/product-detail/customized-DC5-5-2-1mm-barrel_60829384845.htmlhttps://www.alibaba.com/trade/search?fsb=y&IndexArea=product_en&CatId=&SearchText=dc+barrel+cablehttps://www.digikey.ca/products/en/cable-assemblies/barrel-power-cables/464?k=dc+barrel&k=&pkeyword=dc+barrel&sv=0&pv91=387869&sf=0&FV=-8%7C464&quantity=&ColumnSort=0&page=1&pageSize=25
Who makes this connector? - Page 1
Forum section: electronics / projects

author: jc101
author_rank: Frequent Contributor
timestamp: July 26, 2014, 03:51:34 pm
content: I have spent a while searching for this DC barrel connector, I can find plenty of through panel right angle connectors with a locking nut - but I haven't been able to find who makes these. They are a solid black connector inside, with through hole right angle PCB mounting. They are used a fair bit on AV, to prevent leads falling out inside racks etc, this one is from a Kramer product.

author: Chipguy
author_rank: Unknown
timestamp: July 26, 2014, 04:08:27 pm
content: It could help seeing the part of the connector that is inside the enclosure.

author: jc101
author_rank: Frequent Contributor
timestamp: July 26, 2014, 04:11:56 pm
content: Quote from: Chipguy on July 26, 2014, 04:08:27 pmPic of the internal element...

author: Chipguy
author_rank: Unknown
timestamp: July 26, 2014, 05:20:14 pm
content: Manufactureres could be : Switchcraft or Roka... they do something similar

author: kolbep
author_rank: Frequent Contributor
timestamp: July 26, 2014, 05:58:36 pm
content: http://www.switchcraft.com/category.aspx?Parent=943http://za.mouser.com/Connectors/Power-Connectors/DC-Power-Connectors/_/N-axitthttp://cpc.farnell.com/1/1/9837-2-1mm-dc-plug-lockable-mp-121cr.html

author: jc101
author_rank: Frequent Contributor
timestamp: July 26, 2014, 09:09:07 pm
content: Quote from: kolbep on July 26, 2014, 05:58:36 pmThanks, some of these are very close, I suspect the last one above could end up being suitable. Not too expensive either.
Who makes this M12 12 pole sensor connector? HELP! - Page 1
Forum section: electronics / projects

author: TopLoser
author_rank: Unknown
timestamp: December 06, 2023, 09:45:57 am
content: Ok I give in, I've spent far too long looking at pictures and datasheets of M12 connectors and haven't seen anything like this one. Weird thing about is that it's female yet has a threaded body. Obviously I need to find the matching plug, but if anybody can ID the manufacturer/family then that would be a massive step forwards...Bloody Keyence, always wanting to sell you 400 euro cables by using oddball connectors!

author: tszaboo
author_rank: Super Contributor
timestamp: December 06, 2023, 09:55:56 am
content: There is an M12 next to it. Looking at this connector, I don't think this is M12. The thread pitch looks too high and the thread size is larger than on the other connector. And the gender is wrong (oh no, cancelled).

author: DavidAlfa
author_rank: Super Contributor
timestamp: December 06, 2023, 10:02:35 am
content: Looks like a GX12 series but reversed.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: December 06, 2023, 10:13:51 am
content: This maybehttps://www.digikey.co.uk/en/products/detail/hirose-electric-co-ltd/HR10A-10WTR-12S-73/1095570

author: TopLoser
author_rank: Unknown
timestamp: December 06, 2023, 10:45:04 am
content: Quote from: mikeselectricstuff on December 06, 2023, 10:13:51 amI actually ordered one from that series but I got the push/pull type. Looking closer at the datasheet I need the 10TP version for the threaded type, not the 10P one that I tried.Ta much, that's perfect... 15 ordered.

author: TopLoser
author_rank: Unknown
timestamp: December 08, 2023, 04:11:55 pm
content: Quote from: mikeselectricstuff on December 06, 2023, 10:13:51 amPerfect fit and Digikey service was first class, free shipping USA to France in 2 days.
Whole House Solar System - Comments Please - Page 1
Forum section: electronics / projects

author: German_EE
author_rank: Super Contributor
timestamp: December 27, 2018, 09:45:08 am
content: I'm sitting in a room with someone who has lots of ideas about solar power but neither of us are experts in the subject. After much discussion we have decided on the following and I would appreciate some comments:Solar cells on the roof charge a battery bank, maybe 24V truck batteries or maybe a Tesla unit. At night the batteries are topped up using an incoming 230V single phase line which is also used if it's cloudy.The battery bank feeds a 100A 230V inverter, this powers all of the house 24/7If the battery bank is charged then the solar cells heat the hot water tankIf there is hot water AND it's Winter then the solar power is used to pre-heat the water in the under-floor heating which uses a gas boiler.If there is hot water AND it's NOT Winter then the surplus solar power is used to heat the hot tub.Note that selling solar power back to the electricity company is not an option in this case as it's not financially viable. My job is to design and build all of the control circuits for this including a flashy front panel showing what's going on although the 100A inverter will be a commercial unit. After construction everything will of course be inspected and tested by the local power company before connection to the mains.Thoughts? Comments?

author: awallin
author_rank: Frequent Contributor
timestamp: December 27, 2018, 10:37:55 am
content: How much do you need/want to build the controller for this yourself?Aren't there hydrid inverters out there from the big brands (ABB, Fronius, etc.) that do what you want?With the panels and good sun-light the payback time is 10 years or longer - over here in northern europe at least.If you add to that a li-ion battery pack for 10 keur that will make the break-even time even longer?So I guess you need to decide if you want to do it because of economy or because of the environment, or as a hobby/project - or a bit of everything...
Why -30 volts in this oscillator? - Page 1
Forum section: electronics / projects

author: matseng
author_rank: Frequent Contributor
timestamp: July 01, 2015, 05:06:16 am
content: While browsing around for ideas for a rather wide range discrete oscillator I stumbled onto this at one of those generic collect-many-schematics sites. It looks like it's scanned from a 30-40 year old book.http://www.tradeofic.com/Circuit/1627-WIDE_RANGE_OSCILLATOR_FREQUENCY_RANGE_OF_5000_TO_1.htmlAny idea why it's fed with 30 volts instead of flipping the schematics 180 degrees and feed a positive voltage from the top instead which would be the same in regards of this circuit - but of course not for the following circuits.Where could this device have been used with its -30 volts? I know that Telecom equipment use -48 volts, some old UK cars are positive-grounded, but what else?

author: slateraptor
author_rank: Frequent Contributor
timestamp: July 01, 2015, 06:31:38 am
content: The seemingly odd negative voltage rail is application specific. The real takeaway is the general oscillator topology.It's not uncommon to see older analog applications using non-standard rails. I've seen a lot weirder choices in legacy avionics systems...like negative-prime-integer DC rails, or negative DC rails nominally specified to 3 significant digits.

author: Circlotron
author_rank: Super Contributor
timestamp: July 01, 2015, 09:02:09 am
content: The style of drafting says it is from Electronics Australia magazine.

author: Ian.M
author_rank: Super Contributor
timestamp: July 01, 2015, 09:17:38 am
content: The transistors used were introduced in the late 60's. 'upside-down' schematics with a -B rail at the top were more or less standard in the Germanium era due to the difficulty of producing NPN devices and the desire to keep the schematic layout similar to the valve schematics that preceded them.==> the most likely reason for both the odd voltage choice and layout is that it was designed to retrofit some type of testgear from the Germanium era.

author: dom0
author_rank: Super Contributor
timestamp: July 01, 2015, 09:28:40 am
content: That's now the third time I ever saw a complementary differential amplifier. Must be the unloved twin of the LTP ... not surprising, though, as you get two Ube output offset and DC drift.

author: matseng
author_rank: Frequent Contributor
timestamp: July 02, 2015, 01:02:02 pm
content: Quote from: Circlotron on July 01, 2015, 09:02:09 amOh - that's why it's upside down, it's from AustraliaI'm sure you guys have already heard all possible upside down jokes, so I'll stop now.Joking aside, I must say that eevblog s a fantastic place to ask questions about quite esoteric issues. And it seems like nine times out of ten there are some oldtimer that actually used this particular mobile radar unit in the Australian airforce or some experimental computer back in 60's and can answer questions about it.. Frikkin fantastic.
Why 4 different SPI modes? - Page 1
Forum section: electronics / projects

author: zapta
author_rank: Super Contributor
timestamp: November 25, 2023, 05:30:15 pm
content: The SPI standard has 4 modes with two options of the clock polarity and two option for the data phases. I understand the technical aspects of the 4 modes but an curious about the motivation behind then and their adoption in the industry.E.g.What is the reason that there are 4 modes instead of one?Are these 4 modes equality popular in the industry?Is any of them is the clear winner and emerges as the most common one?Do different IC vendors stick to different modes?

author: slugrustle
author_rank: Frequent Contributor
timestamp: November 25, 2023, 06:00:28 pm
content: My guess would be that there are four modes because all are possible and no particular mode seems easier or more difficult to implement than any of the others. I think it would be very difficult to force all IC manufacturers to only use one of the modes, as nice as it would be for everything to be consistent.

author: jpanhalt
author_rank: Super Contributor
timestamp: November 25, 2023, 06:03:01 pm
content: From my practical experience, I had 2 SPI device on the same module (a GLCD and a MAXIM thermocouple amplifier) each worked on 2 modes, both only one mode worked in common.EDIT: I include all 4 modes on my starting template for that chip family (PIC16F1xxx). It is easy to try each.

author: Benta
author_rank: Super Contributor
timestamp: November 25, 2023, 06:56:23 pm
content: Back when SPI was defined (40+ years ago), no consensus was present and it was designed to be flexible/universal.Today, the most common mode is the one that fits simple I/O expanders like 74HC165, 74HC589, 74HC595, 74HC597 etc.

author: ejeffrey
author_rank: Super Contributor
timestamp: November 25, 2023, 07:26:48 pm
content: Probably because it stated as a defacto standard that people implemented different ways depending on what was most convenient or without too much concern for whether they are doing it the same as anyone else. Mode 0 is by far the most popular especially on newer devices.Different polarity can also be useful if you are interfacing with different logic families or have a inverting buffer or level translator between devices. If you are interfacing with simple discrete gates or shift registers you might end up with whatever variant you have the gates handy for.
why add a resistor in parallel with gas discharge tube? - Page 1
Forum section: electronics / projects

author: mlloyd1
author_rank: Contributor
timestamp: October 01, 2024, 09:57:53 pm
content: Looking at a consumer electronic product for US market that uses a GDT paralleled with a 200K ohm/1/2w resistor and that combination is in series with a 15ohm/5w to across the powerline protect the product from surges.The product is undamaged when hit with surges (tested to about 6KV) and resumes operation afterwards, just as it should.I understand the reason for the series 15-ohm resistor (basically limits current when GDT fires), but can't explain the 200K in parallel.My WAG is something to do with maybe helping the tube recover faster after the internal plasma returns to gaseous state after the surge.But like I said, that's a WAG.Anybody know the "REAL" answer?Enquiring minds want to know ....mlloyd1

author: Bud
author_rank: Super Contributor
timestamp: October 01, 2024, 10:35:51 pm
content: Perhaps to bleed static so it does not build up.

author: jbb
author_rank: Super Contributor
timestamp: October 02, 2024, 01:50:08 am
content: Could it be a bleeder resistor for some capacitor elsewhere in the box?
Why are many voltage references 2.048 or 4.096V - Page 1
Forum section: electronics / projects

author: microbug
author_rank: Frequent Contributor
timestamp: September 15, 2014, 03:22:51 pm
content: Pretty much what it says in the title. Why is 2.048V so common for voltage references?

author: senso
author_rank: Frequent Contributor
timestamp: September 15, 2014, 03:27:51 pm
content: To use with DAC's and ADC's, so each bit is a nice value, for example, a 4.096Vref with a 12 bits ADC will translate to 1mv per LSB( 4.096/2^12 = 0.001v), if you used a 5v reference each LSB would have a value of 5/4096 = 0,00122

author: microbug
author_rank: Frequent Contributor
timestamp: September 15, 2014, 03:29:04 pm
content: :facepalm: thanks!

author: mrkev
author_rank: Regular Contributor
timestamp: September 16, 2014, 12:26:43 am
content: Btw same goes for clock xtals 32,768kHz. It's a nice round number, just in base 2...

author: sacherjj
author_rank: Frequent Contributor
timestamp: September 16, 2014, 12:46:10 am
content: You also get crystal frequencies like 14.7456 Mhz and 18.432 Mhz instead of 16 and 20, for error free timing on baud rates.

author: NiHaoMike
author_rank: Super Contributor
timestamp: September 16, 2014, 02:02:21 am
content: http://en.wikipedia.org/wiki/Crystal_oscillator_frequenciesThat's a big list of common crystal frequencies and explanations of why they are common.

author: sacherjj
author_rank: Frequent Contributor
timestamp: September 16, 2014, 03:02:30 am
content: Quote from: NiHaoMike on September 16, 2014, 02:02:21 amThat is a nice list. Interesting read.
Why are 'short scale' panel meters synonymous with industrial applications?   - Page 1
Forum section: electronics / projects

author: e100
author_rank: Frequent Contributor
timestamp: June 20, 2018, 08:48:07 am
content: By short scale I mean the type where it looks like a third of the meter has been chopped from the right hand side so the coil and magnet are in the bottom right hand corner and the needle can only move through 90 degrees.Is this supposed to give better at a glance readability? If so, wouldn't things like car dashboard instruments adopt the same look?

author: Gyro
author_rank: Super Contributor
timestamp: June 20, 2018, 09:04:52 am
content: I'm not sure they are actually that short. If you rotate the picture by 45' they look about the same span as a normal meter movement. Linearity starts to suffer once you get much past 90'. I've seen ~270' meters used in similar control room applications, not sure how how they work though.The meters shown do have visual impact though, maybe easier to spot deviations in an array.

author: David Hess
author_rank: Super Contributor
timestamp: June 20, 2018, 02:34:24 pm
content: I think it is just a matter of making the best use of available space.

author: e100
author_rank: Frequent Contributor
timestamp: June 20, 2018, 04:21:52 pm
content: Quote from: Gyro on June 20, 2018, 09:04:52 amI had assumed that 'short scale' was the official name for this type of meter layout with the axis in the right hand corner, but now I don't know if it has an official name at all.Quote from: Gyro on June 20, 2018, 09:04:52 amIs it perhaps the east/west everything is dead, north/south everything is on fire user interface paradigm?

author: duak
author_rank: Super Contributor
timestamp: June 20, 2018, 05:13:37 pm
content: Many race cars have their tachs and other gauges set up so that their nominal or maximum readings occur with the meter needle vertical to make it easier to see if one is out of range. These gauges are usually round so they can be easily rotated, Rotating a square meter would look goofy if not downright confusing.The cynic in me says it's a fashion statement that says 'Industrial' rather than simply 'Professional'. (Sometimes I think we need a new word that means what professional used to mean, especially in ads.)Industrial meters often use moving iron movements rather than moving coil (D'arsonval) movements. I believe this allows for 270 (actually 240) degree sweeps. I also remember seeing a thermal movement where a heated wire indirectly pulled on a gear train to drive the needle. This could measure the actual RMS current rather than the average.

author: David Hess
author_rank: Super Contributor
timestamp: June 20, 2018, 05:22:14 pm
content: Moving iron movements are RMS responding.

author: Gyro
author_rank: Super Contributor
timestamp: June 20, 2018, 06:06:02 pm
content: 240' apparently possible in moving coil meters too...https://www.hobut.co.uk/analogue-panel-meters-3/240-degree-din-panel-meterIt looks as if they use a 'half coil', the turns must pass through the center of the magnet...
Why are so few domestic automatic or remote switches rated for inductive loads? - Page 1
Forum section: electronics / projects

author: e100
author_rank: Frequent Contributor
timestamp: February 18, 2021, 01:04:43 pm
content: I'm thinking of things such as the old style mechanical timers and the newer smart home devices that operate over WiFi etc.Does the inclusion of a snubber network and therefore the high leakage current make it difficult or impossible to get approval for this type of device?

author: mvs
author_rank: Frequent Contributor
timestamp: February 18, 2021, 03:38:45 pm
content: You can get KNX switch actuators for inductive loads... but they are not cheap as ESP32 based smart home devices.

author: penfold
author_rank: Frequent Contributor
timestamp: February 18, 2021, 03:59:45 pm
content: Quote from: e100 on February 18, 2021, 01:04:43 pmIts most likely a cost based decision, a nice simple and cheap triac is perfect for resistive loads, but in reality needs quite a few more components to be a good switch for inductive loads, when the voltage and current are out of phase significantly they can be difficult to guarantee switching on and switching off

author: rob77
author_rank: Super Contributor
timestamp: February 18, 2021, 06:31:10 pm
content: nowadays it's a quite niche market , so it makes no sense to mass produce them.there is no need to switch inductive loads in a modern household unless you want to remotely switch on your old vacuum cleaner of course

author: james_s
author_rank: Super Contributor
timestamp: February 18, 2021, 07:46:09 pm
content: The only use case I have is my air compressor. I tried using a wifi controlled switch on it and it was nice, I could switch it on from inside and let it fill up before I went out to the garage. The relay didn't last long though so I'm going to replace it with a contactor or SSR.

author: e100
author_rank: Frequent Contributor
timestamp: February 19, 2021, 06:07:55 am
content: Quote from: penfold on February 18, 2021, 03:59:45 pmAs far as I can tell most smart switches use mechanical relays. I've never seen a spec that specifies a minimum load for reliable operation.

author: penfold
author_rank: Frequent Contributor
timestamp: February 19, 2021, 02:16:31 pm
content: In that case, short of common sense suggesting "if a switch is off, I expect the plug's live to be completely off" I'm not aware of any regulation that states that, so it may not be a purely regulatory thing. However, it would be likely that the leakage from a snubber designed to allow arc-free switching at 10A purely inductive load may be just low enough impedance/high enough leakage that the standby PSU of a TV might "try" to turn on
why are solar-cells only singlesided? - Page 1
Forum section: electronics / projects

author: smashIt
author_rank: Contributor
timestamp: July 02, 2013, 10:58:06 pm
content: as far as i know the silicon-wafer is still the thing that drives the cost for a solar-panelso why aren't they using both sides of the wafer?all it would take is a structured mirror to guide the light to its backside (see the attachments for some drafts)does anyone know a reason why it's not done?or are there already such panels?all i've found are panels with solar-cells on the backside to collect stray light

author: edavid
author_rank: Super Contributor
timestamp: July 02, 2013, 11:11:11 pm
content: Quote from: smashIt on July 02, 2013, 10:58:06 pmIt's not... if it were, everyone would use concentrators.
Why are some touch screen products more sensitive to static electricity? - Page 1
Forum section: electronics / projects

author: monster_of_electronics
author_rank: Contributor
timestamp: April 12, 2016, 01:00:00 am
content: For example, some cheap video recorders will stop recording if a person who has built up static electricity, touches the unit while recording. Why might this happen more in budget products? What corners are they likely to be cutting?

author: Kilrah
author_rank: Unknown
timestamp: April 12, 2016, 04:40:30 am
content: Grounding, shielding, and testing/reworking to make sure they're effective...

author: German_EE
author_rank: Super Contributor
timestamp: April 12, 2016, 05:05:30 pm
content: There are two types of touch screen, resistive touch and capacitive. I suspect that one may be more sensitive to static than the other.

author: grifftech
author_rank: Frequent Contributor
timestamp: April 14, 2016, 02:43:37 am
content: Quote from: German_EE on April 12, 2016, 05:05:30 pm3 actually you forgot optical (not very common).

author: coppice
author_rank: Super Contributor
timestamp: April 14, 2016, 04:59:10 am
content: Quote from: grifftech on April 14, 2016, 02:43:37 amOptical is far from rare. Kindles are probably the highest volume use, but optical gets used in a number of applications where surface dirt or electrical noise make other techniques unstable.
Why can't format old floppy disks? - Page 1
Forum section: electronics / projects

author: Circlotron
author_rank: Super Contributor
timestamp: December 01, 2022, 05:59:52 am
content: Got a pile of old 3-1/2 inch diskettes. May of them date to the mid 90s, some even earlier. Nothing important on them. A few I can actually read the table of contents, even fewer I can actually read some of the files. Presumably the magnetic domains on the disk have gotten weak over the years. I can understand that. But why wouldn't they be able to be formatted? I thought that would make them good as new. Totally blank of course, but quite usable if I wanted to.

author: TERRA Operative
author_rank: Super Contributor
timestamp: December 01, 2022, 06:39:03 am
content: Probably physical degradation due to outgassing/oxidation/mold/etc.Also, make sure your read heads in your floppy drive are perfectly clean (isopropyl alcohol is useful here) and the mechanical parts arw well lubricated.

author: DavidKo
author_rank: Frequent Contributor
timestamp: December 01, 2022, 08:34:03 am
content: It was quite common even in old days. To find disk without bad sectors is quite tricky.Based on this siteDiskDupecan help you.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: December 01, 2022, 09:23:43 am
content: ISTR 720K and 1.4M disks had different magnetic characteristics, so maybe some compatibility issues using the wrong type?

author: xmris
author_rank: Contributor
timestamp: December 01, 2022, 09:53:43 am
content: @OPthismay help you, I also have a lot of floppies most of them purchased early 90s and I managed to reformat a lot of them. Btw as mentioned above, mould is an issue, esp ON the floppies, check them for signs of it, then clean -gently- with some cotton pad with IPA.
Why chips die (article) - Page 1
Forum section: electronics / projects

author: analogo
author_rank: Regular Contributor
timestamp: November 26, 2018, 07:13:28 am
content: A quite interesting retrospective (with numbers) on why some wafers have low yield rates:https://semiengineering.com/why-chips-die/

author: nsrmagazin
author_rank: Regular Contributor
timestamp: November 26, 2018, 02:07:47 pm
content: We know too well why chips die and why it gets worst every year.
Why connecting a capacitance across Gate and Source of a MOSFET makes it Stable? - Page 1
Forum section: electronics / projects

author: Arsh ahmad
author_rank: Regular Contributor
timestamp: July 12, 2022, 05:19:35 am
content: I am designing a constant current source using OPMAP and a P channel MOSFET. At low resistive loads the MOSFET goes unstable but when I connect a 100nF capacitor between Gate and source the current becomes stable. But I am not able to figure out why is it so.

author: ZeTeX
author_rank: Frequent Contributor
timestamp: July 12, 2022, 05:24:38 am
content: Because you're slowing the response of the loop. The capacitor has to charge to appropriate voltage, thus slowing down the speed of your feedback loop. This might reduce oscillation with specific op amps and load.The common way to stabilize the loop and reduce oscillation is by a few compensation techniques.Have a look at the following thread, and read the commentshttps://www.eevblog.com/forum/projects/dynamic-electronic-load-project/

author: Roehrenonkel
author_rank: Frequent Contributor
timestamp: July 12, 2022, 05:42:38 pm
content: Hi Arsh ahmad,maybe try a gate-resistor (100R...1k) instead of the cap.Good luckEdit: To clarify: Not replacing the cap, but in series to the gate (as near as possible), ommit the cap.

author: SiliconWizard
author_rank: Super Contributor
timestamp: July 12, 2022, 06:30:57 pm
content: This of course is a compromise between stability and speed. You don't want the current source to oscillate, but you may have requirements in terms of speed, in particular if you either need to set your current source from a varying voltage, or if the load itself is not stable, or a combination of the two.
Why connecting scope probe makes offline LED driver malfunction? - Page 1
Forum section: electronics / projects

author: ocset
author_rank: Super Contributor
timestamp: September 08, 2017, 10:06:53 pm
content: Hello,Please can you tell why the attached offline LED driver test setup makes the LED driver not work properly whenever the coaxial probe is connected to the scope. As soon as we disconnect the BNC of the coaxial probe from the scope, the LED driver works properly again.Do you know what is happening?The strange thing is that this set-up was working fine a few weeks ago and giving nice scope shots of the current waveform via the sense resistor.The scope is a Tenma 72-8705A….http://uk.farnell.com/tenma/72-8705/oscilloscope-2ch-50mhz-1gsps/dp/1836059

author: Ice-Tea
author_rank: Super Contributor
timestamp: September 09, 2017, 06:05:36 pm
content: Coaxial probe? If you are not using a high impedance probe you're adding a 50 ohm load...

author: Ice-Tea
author_rank: Super Contributor
timestamp: September 09, 2017, 06:08:09 pm
content: Also: sure the AC psu is isolated?

author: ocset
author_rank: Super Contributor
timestamp: September 09, 2017, 07:55:59 pm
content: Thanks, but the Tenma 72-8705A scope input is a 1 Meg input impedance input.Also, the AC output PSU is definetely isolated. We tied the live output to earth ground and it still works fine at 230VAC output so it must be isolated.

author: StillTrying
author_rank: Super Contributor
timestamp: September 09, 2017, 08:48:59 pm
content: If the current sense resistor's value is very low ( 0.1R ? ) the coax loading shouldn't have any effect.Have you tried touching just the shields/gnds connection of the cable's and the scope's BNCs together to check if it's the GNDs connecting causing it, even if they are DC isolated.

author: ocset
author_rank: Super Contributor
timestamp: September 10, 2017, 01:25:15 am
content: Thanks ill try that, ....another strange thing is that the attached connection of a "normal" scop probe to the LED driver wasnt nearly so noisy.(ive drawn the current limiter in aswell in this diagram)...It was noisy to an extent, but as long as you let the led driver get going before connecting up the normal scope probe then it was ok.....whereas the DIY coaxial probe never allowed the led driver to work properly.
Why CPU DDR Memory Controller Has 2 Clock Outputs? - Page 1
Forum section: electronics / projects

author: electronx
author_rank: Regular Contributor
timestamp: August 12, 2023, 12:21:00 pm
content: I'm trying to understand the ddr structure for the iMX6 Rex Module. The CPU used is the MCIMX6Q5EYM10AC model from the nxp i.mx quad series.https://www.nxp.com/docs/en/data-sheet/IMX6DQCEC.pdfhttps://www.imx6rex.com/wp-content/uploads/2016/04/iMX6-Rex-Module-Schematic.pdfA configuration was made using 4 x16 DDR3 DRAM, with a total of 64 word lengths. So far everything is great. Why are there 2 (DRAM_SDCLK_0, DRAM_SDCLK_1 ) clock outputs?Does it matter from which clock source we feed the ddr chips?

author: DavidAlfa
author_rank: Super Contributor
timestamp: August 12, 2023, 12:50:15 pm
content: Because it's a differential signal!https://www.edn.com/double-data-rate-sdramthe-next-generation/

author: ejeffrey
author_rank: Super Contributor
timestamp: August 12, 2023, 12:54:35 pm
content: That's not it, the diagram shows two differential pairs.

author: DavidAlfa
author_rank: Super Contributor
timestamp: August 12, 2023, 01:17:34 pm
content: Ah didn't see he bottom one!Quotehttps://www.micron.com/support/~/media/D546161C2C6140BCB0BAEE954AA53433.pdf

author: electronx
author_rank: Regular Contributor
timestamp: August 12, 2023, 01:34:30 pm
content: Quote from: DavidAlfa on August 12, 2023, 12:50:15 pmThanks for your help. but I'm not as noob as you thinktwo different clock source (every clock source is differential signalled)

author: DavidAlfa
author_rank: Super Contributor
timestamp: August 12, 2023, 03:01:41 pm
content: It's all your fault, you should have stated 4 clock signals!