hybridfree/eevblog-posts huggingface dataset:
Flat europlug plug-in socket with switch, anyone? - Page 1
Forum section: electronics / general

author: bitwelder
author_rank: Super Contributor
timestamp: October 24, 2021, 05:32:34 pm
content: One of my pet peeves of modern consumer electronics are small plugpacks without a switch on the mains side.Being in Europe, those often comes with a flat Europlug (aka 'CEE 7/16 Alternative II')To provide that switch function I was searching for some type of plug-in switched socket, to be placed between mains socket and the plugpack.The ones for the larger Schuko type (CEE 7/3 & 7/4) are not uncommon, e.g.https://www.reichelt.de/de/en/earthed-plug-adapter-with-2-pole-switch-ssd-1-ws-2p-p127510.htmlbut I couldn't find much for the Europlug. The best I found was something that has a short power cord between the plug and the sockethttps://www.reichelt.de/de/en/flat-european-plug-with-integrated-switch-ssd-1-euro-sw-p135040.htmlbut I'd like to have something made as one tiny block, like the Schuko one above, but as tiny and minimalist as possible.Has anyone found anything like that?

author: Benta
author_rank: Super Contributor
timestamp: October 24, 2021, 07:34:31 pm
content: Never seen one. Why not just pull the plug?

author: NiHaoMike
author_rank: Super Contributor
timestamp: October 25, 2021, 03:05:36 am
content: More complex then necessary, but perhaps a smart plug would work? Pretty much every one I have come across will work as a dumb switch if not configured, but I would suggest one that supports open source firmware like Tasmota so you can customize it later on.

author: bitwelder
author_rank: Super Contributor
timestamp: October 25, 2021, 08:56:01 am
content: Quote from: Benta on October 24, 2021, 07:34:31 pmYou never had the pleasure to wrestle with an extension cord socket that has tight safety shutters?Quote from: NiHaoMike on October 25, 2021, 03:05:36 amNo thanks. Especially if the point is to cut off mains, adding powered smarty-pants stuff won't help.

author: david77
author_rank: Frequent Contributor
timestamp: October 25, 2021, 09:22:14 am
content: Not for Europlug specifically, but very compact.https://www.amazon.de/Steckdosenschalter-Schuko-Stecker-schaltbar-Steckdosenadapter/dp/B0072I0V02But it seems nobody makes these anymore? Can't find much.

author: RoGeorge
author_rank: Super Contributor
timestamp: October 25, 2021, 11:17:59 am
content: I'm using socket extender cords with 3-10 sockets at the other end and a common power switch, so it can be placed in a comfortable to reach and/or hidden spot, and can turn on/off a whole group of devices at once.Never seen a socket adapter with a switch for a single flat socket plug.

author: bitwelder
author_rank: Super Contributor
timestamp: October 26, 2021, 11:21:26 am
content: Quote from: david77 on October 25, 2021, 09:22:14 amWell, googling that picture finds them in (small) stock at Bürklin.https://www.buerklin.com/en/German-Schuko-style-plug-with-switch/p/05N935BTW, nice minimalist style!
Can Switch with Faulty Cable Damage Electronics? - Page 1
Forum section: electronics / general

author: Boris_yo
author_rank: Frequent Contributor
timestamp: October 24, 2021, 12:52:13 pm
content: Hello,I ordered cheap USB switch to supply constant power to my small security home camera. I used a power bank to power it but it was inconvenient.Months ago that switch worked good. I left it collecting dust for a few months until I decided to do the wiring and use it for camera. I tested switch again by collecting small USB light. I noticed that connection was not stable and I had to bend the cord at certain degree for it to work:https://streamable.com/7z4hqmQuestion though. Should I keep it that way as on a photo below or throw it away and buy a new switch? Despite consistent power supply, are there still varying power that can damage camera?Thanks.

author: madires
author_rank: Super Contributor
timestamp: October 24, 2021, 02:29:23 pm
content: Most likely a broken wire. Cheap USB cables have usually only very thin wires with a few strands, causing also a high wire resistance. Better replace the cheap wire with a more suitable one. You could buy an USB extension cable, cut it in two halves and recycle the switch (does look like a power cord switch). The camera should survive short "power outages", but the bad cable might create some noticeable voltage drop.

author: Boris_yo
author_rank: Frequent Contributor
timestamp: October 25, 2021, 02:42:04 am
content: By recycle switch you mean continue using it?Never cut USB cord and not familiar with which cords transfer data and which transfer power. Haven't used soldering equipment many years too by way.

author: coppercone2
author_rank: Super Contributor
timestamp: October 25, 2021, 02:50:12 am
content: essentially if its a data line its OK but if its a power or ground line it could be a fire hazard/overheating hazard since it might be prone to getting hot in a nonlinear fashion when its used broken.

author: madires
author_rank: Super Contributor
timestamp: October 25, 2021, 11:02:47 am
content: Quote from: Boris_yo on October 25, 2021, 02:42:04 amYes. It's up to you to decide what to do.

author: NiHaoMike
author_rank: Super Contributor
timestamp: October 25, 2021, 12:42:49 pm
content: Quote from: Boris_yo on October 25, 2021, 02:42:04 amGreat time to learn! Carefully cut back the plastic around the USB port and you might be able to resolder the bad connection.
Need help from someone working in the field - Page 1
Forum section: electronics / general

author: jknightandkarr
author_rank: Contributor
timestamp: October 23, 2021, 07:40:05 pm
content: Hey, wondered if some one here that works as an electronics engineer or something similar n need help bad... Got informal interview to do by tonight for my career class final and so far no responses on messages i sent out on an alt web site an need you name, company name n location, job title n then just 10 questions answered please. Please message me if you can help.1)How did you get interested in Electronics engineering?2)What would you say your biggest challenge has been in Electronics Engineering?3)What are the highest valued skills in Electronics Industry?4)Are there other skills that could be useful to use?5)what kind of products does your company create/work on?6)what is the company's goal?7)Has there been anything in the electronics industry that surprised you or does it seem like a steady changing field?8)Do you see any particular changes in the industry coming or think that should happen? Such as designing alternative methods for electric vehicles to charge or last longer between charges.9)What are the most important tools that I should know how to use properly for an entry level position?10)What might be the best position for me to start in for Electronics Engineering?If you can help i would be very grateful! Thanks!

author: EPAIII
author_rank: Super Contributor
timestamp: October 26, 2021, 07:50:49 am
content: Here you go, but you probably won't like it. Or rather, your professor probably won't.In RED below:Quote from: jknightandkarr on October 23, 2021, 07:40:05 pmGood luck!

author: jpanhalt
author_rank: Super Contributor
timestamp: October 26, 2021, 10:24:04 am
content: Quote from: jknightandkarr on October 23, 2021, 07:40:05 pmHow did it turn out?I read your post several times, and it was still not clear what you wanted. For starters, do you need help or do you want to find and engineer that  needs help?One assumption is that those are interview questions you developed and will be graded on them based in part on the responses you got.
First it was Keysight, now it is AD - Page 1
Forum section: electronics / general

author: perdrix
author_rank: Frequent Contributor
timestamp: October 26, 2021, 08:56:59 am
content: First Keysight Germany mandated that Keysight organisations in Europe shall only supply to companies.Now AD Germany are saying they will only supply to VAT registered organisations, and I have heard unconfirmed reports of other companies acting in the same way.What piece of (probably German or EU) legislation is causing companies to act in this way?Is there anyone who is in a position to talk to the sponsors of that legislation to get it changed?D.

author: harerod
author_rank: Frequent Contributor
timestamp: October 26, 2021, 09:50:38 am
content: In these trying times professional customers buy most of the available stock anyway, but there is more to it.A major reason to leave private customers to specialists (e.g. certain distributors) in general, would be low return on effort and customer protection laws.There is the argument about satisfied private customers acting as multiplicators. Again, those can be served by the distributors. In rare cases, say the recently introduced ADR1000, ways can be found to supply private enthusiasts with components.This whole topic takes me back thirty, forty years, when a private customer had to do with components sold by distributors. In contrast, today that customer has the option of shopping worldwide. One can only assume that certain companies are willing to sacrifice business, for the benefit of not having to deal with a certain type of customer directly.Edit: spelling

author: Psi
author_rank: Super Contributor
timestamp: October 26, 2021, 10:02:05 am
content: It's probably something many companies have wanted to do for a while.But they didn't want to be the first and only one to do it.So they did the smart thing and waited for someone else to do it first and watch for any backlash
Stepper motor ramp guidance - Page 1
Forum section: electronics / general

author: Puffie40
author_rank: Regular Contributor
timestamp: October 21, 2021, 11:10:08 pm
content: I am developing a two-axis stepper motor control board using TMC5160 driver chips connected to a raspberry Pi for a camera pan-tilt.one issue I am trying to address is getting the tilt to safely slow down without slamming into its mechanical stops. the pan-tilt has optical limit switches, but the challenge is at a high enough motor speed, inertia carries the axis into the mechanical stop.Would having a more aggressive deceleration ramp in the controllers help this? Is there some guidelines available for configuring a motor acceleration ramp? The TMC5160 datasheet is a little vague about this other than the ramp generator section on page 81.

author: beanflying
author_rank: Super Contributor
timestamp: October 21, 2021, 11:57:39 pm
content: Try not to reinvent the wheel maybe so this might helphttps://www.eevblog.com/forum/programming/synchronize-stepper-motor-movement/msg3545858/#msg3545858

author: mawyatt
author_rank: Super Contributor
timestamp: October 22, 2021, 03:59:55 pm
content: We've used various Trinamic controllers for precision work with focus stacking fixtures which utilize precision linear rails. The data sheets show velocity profiles and the control parameters that influence such, and a couple that control the deceleration mode. Setting these parameters up correctly can be tricky, so best to study the data sheet details and run various experiments with the control parameters to get a "feel' for how they behave.Best,
Check out this Mechanical/electronics lab! - Page 1
Forum section: electronics / general

author: Traceless
author_rank: Frequent Contributor
timestamp: October 21, 2021, 08:06:43 am
content: Wow I guess that's the most impressive in-home shop I've seen so far. What is even more impressive than the shop itself is the amount of knowledge, skill and experience its owner seems to have. Owning such a shop is one thing but actually being able to makeproperuse of it is a different story.

author: nuh
author_rank: Newbie
timestamp: October 22, 2021, 07:25:59 am
content: very nice

author: jpanhalt
author_rank: Super Contributor
timestamp: October 22, 2021, 10:35:22 am
content: Nice collection. Particularly liked the lathe chuck and Noga indicator holder. If you are still messing with cheaper/older holders, you will appreciate a Noga. I have 2. They make setup easy.https://www.noga.com/Products/afat/Articulated%20Holders%20FAT/NF61003/NF_Holder_-_NF61003

author: Pinkus
author_rank: Frequent Contributor
timestamp: October 22, 2021, 11:48:22 am
content: Well, impressive and definitely something i'm envious of (in a positive sense). However, either this guy doesn't have a wife, or she has a shoe collection from here to the moon.btw: you should look at the other videos from Dan Gelbart (especially 'building prototypes')- very probably you will learn something. I definitely did.https://www.youtube.com/channel/UCYA1VjSKXgNVh03wjw_HSRA
Help identify LEDs - Page 1
Forum section: electronics / general

author: Logan
author_rank: Frequent Contributor
timestamp: October 21, 2021, 03:52:05 pm
content: Hello.I got some LEDs from a Chinese source, they supposed to be OSRAM LEDs, but I don't know the model number(and don't even know if they are genuine OSRAM parts).Can anyone look at the 5 photos and try to tell the model number? And is it possible to tell whether they are real or clone by those pictures?Thanks.

author: georges80
author_rank: Frequent Contributor
timestamp: October 21, 2021, 04:13:50 pm
content: If it was important that you knew the model/brand, then you should have bought them from a US distributor.If it wasn't important, then as long as they light up (and continue to do so) you should be happy.I'd be super impressed (and skeptical) if someone can tell you the part number and manufacturer - I can't do that even with a Digikey sourced LED once it is out of its shipping bag.cheers,george.

author: Benta
author_rank: Super Contributor
timestamp: October 21, 2021, 06:20:44 pm
content: Best comment ever.The distinction between "infinite cheapness" and "supply chain security" is the central point.
How ASML Won Lithography (& Why Japan Lost) - Page 1
Forum section: electronics / general

author: PlainName
author_rank: Super Contributor
timestamp: October 29, 2021, 11:03:22 pm
content: Essentially a web page made 15 minutes long and taking up more storage to boot. What on Earth does that video supply that text and pictures wouldn't? There's nothing moving in it at all and plenty of black screen moments (although 'moments' suggests 'brief' and many aren't).I'd've like to have read that, but then I could skip the bits I know and take my time with the rest. As a video, pacing is out of my control and I can't easily skip forward or back to check stuff.Sorry, but this is an excellent example of how YouTube financials just fucks stuff up. Dunno how he manages to get 140K subscribers, but without the income from those it could have been an interesting web page.
Completly passive precise AC-mains voltage regulation. - Page 1
Forum section: electronics / general

author: BrianHG
author_rank: Super Contributor
timestamp: October 17, 2021, 02:02:48 pm
content: Ok, I always figured this was possible, but not with this precision...

author: Tomorokoshi
author_rank: Super Contributor
timestamp: October 17, 2021, 05:02:48 pm
content: That was bloody interesting!

author: bob91343
author_rank: Super Contributor
timestamp: October 17, 2021, 05:32:47 pm
content: I have a couple of those, built into other gear. However, these days the power lines are much better regulated and have made constant voltage transformers unnecessary. The main vendor of them was Sola.

author: james_s
author_rank: Super Contributor
timestamp: October 17, 2021, 06:11:18 pm
content: I used to encounter those Sola regulating transformers now and then but I haven't seen one in a while now. They do work very well at regulating, although as I recall the output waveform is not very nice and they also run hot so waste a lot of power. I don't really see them as being necessary in most cases now, power supplies are pretty robust and computers and such are not particularly sensitive at all to voltage fluctuations.

author: TimFox
author_rank: Super Contributor
timestamp: October 17, 2021, 06:17:51 pm
content: Solas are very useful devices, a bit heavy, with a required resonating capacitor. Some comments:1. They are/were available either as approximately square wave outputs (great for rectifiers) or "harmonic neutralized" with reasonably sinusoidal outputs.2. They are good at rejecting changes in input voltage and load current, but the output varies directly with frequency, so they must be purchased for 50 or 60 Hz use.3. Back before 1970, the electronics shop at Argonne National Laboratories built most of their vacuum-tube circuits using Sola transformers that combined plate supply and heater supply windings to simplify voltage regulation requirements.

author: BrianHG
author_rank: Super Contributor
timestamp: October 17, 2021, 11:45:40 pm
content: Here is part 2 with scope shots. Yes, the signal turns into a square wave at high input voltages.
Magical magnetic copper - Page 1
Forum section: electronics / general

author: Lango1818
author_rank: Contributor
timestamp: October 20, 2021, 09:27:02 am
content: I recently purchased a pack of alligator test leads from Jaycar. I was wondering why the leads seamed to heat up under a couple of amps current flow. They also fell apart at a regular gate.Any how I was playing with a magnet out of a microwave oven when I noticed the leads were magnetic. WOW I thought, Magnetic copper. Whilst to be fair to Jaycar and Altronics (they sell the same magical magnetic copper test leads). They do not say on the packet that the leads are copper. I just assumed they might be. Any way, I have ordered some silicon insulated copper wire and some decent alligator clips and I will make my own non magnetic test leads

author: Berni
author_rank: Super Contributor
timestamp: October 20, 2021, 09:39:39 am
content: I never trusted these cheep alligator clip wires very much since they always use very thin wire, but i have never seen one with fake copper coated steel wire.I often swap out the wires on these clips with something thicker, and solder it properly. The original ones wires are usually just crimped into the crocodile clip with the insulation included. This works for some time but then develops a intermitent bad connection, as a result causing me lots of frustration when things mysteriously stopped working at random times. It also pulls out if you jank the wire too hard. But the crocodiles tend to be just fine, so all it needs is a new wire and proper soldering to hold it on.Oh and copper wires also become 'magnetic' once you pass enough current trough it. Above about 100 or 200 Amps of DC you get magnets sticking to the wire like its made out of steel. This is why it is important to tie down wires carrying large pulse currents as the wires will try to 'run away' due to there own magnetic field.
LCSC shipping cost/time differences? - Page 1
Forum section: electronics / general

author: MT
author_rank: Super Contributor
timestamp: October 18, 2021, 02:23:20 am
content: Whats the difference between these two shipping methods? The second one is that China post? Are both air mails?For example 843gram Austria/Euro zone i got:Royal Mail and Austrian Post. 20euro, 15 to 30 days.Global Direct Standard Line. 22euro, 7 to 15 daysRoyal mails home page gives somewhat different prices and delivery times!https://www.royalmail.com/sending/international/country-guides/austriaLCSC also want to charge you for failed shipments while Royal Mail have those fails/returns for free?!https://www.lcsc.com/faqs?id=23

author: retiredfeline
author_rank: Frequent Contributor
timestamp: October 18, 2021, 02:44:01 am
content: GDSL could be any of many China based companies, I don't think CP has a monopoly on parcel carriage. With times like that I doubt it would be by sea, not with the supply chain bottlenecks there.

author: John B
author_rank: Frequent Contributor
timestamp: October 18, 2021, 09:53:26 am
content: From memory, the cheapest option used a service called Yuntrack or Yunexpress? Obviously I was a little concerned at first, but all parcels arrived no issues, sometimes faster than their quoted delivery time frame. Definitely worth the savings over DHL, unless you absolutely have to have some item within ~3 days.
Maplin multitool speed control fault - Page 1
Forum section: electronics / general

author: CambridgeMart
author_rank: Regular Contributor
timestamp: October 18, 2021, 12:05:03 am
content: I have a Maplin 170W 230V multitool that I bought a few years ago. When using it yesterday, the speed control kept resetting to minimum (8000RPM). This model has a digital speed controller with Up and Down buttons and an LCD that shows the speed setting.Given that Maplin have gone the way of the Dodo, I can't seek help from them; I have discovered that the same tool was sold as a Batavia Maxxseries Rotary Tool 170W, but trying to track down any information on this version hasn't produced any results.Has anyone come across this type of fault on a similar tool?
Incredible hand made micro space telescope - Page 1
Forum section: electronics / general

author: nali
author_rank: Frequent Contributor
timestamp: October 17, 2021, 10:57:20 am
content: This appeared in my feed and blew my mind a little bit. Making a tiny Schmidt-Cassegrain telescope out of a solid piece of glass for use in a Cubesat, and doing all the lapping etc entirelyby handin a spare room at home.
I Need help understanding data sheet math  - Page 1
Forum section: electronics / general

author: ptricks
author_rank: Frequent Contributor
timestamp: October 20, 2021, 12:02:23 pm
content: I'm working with the IC LX27901 and have a situation where the circuit does not operate unless an oscilloscope probe is touching the pin that sets the operating frequency, the frequency set by an RC circuit.The data sheet section below shows how to determine the correct values but I am not understanding how they are doing the math, mainly the notation with the .94 and .91 above the values. It has been about 30 years since math classes so maybe I need a refresher.

author: RoGeorge
author_rank: Super Contributor
timestamp: October 20, 2021, 12:30:03 pm
content: Unless specified otherwise, that notation usually means "to the power of", in programming languages the symbol is either "^" or "**", on a pocket calculator is the \$ X^Y \$ key. For example \$ 330 ^ {0.91} \approx 195.82 \$Where did you get that pdf? I've searched for LX27901, and this datasheet is the first result returned, with a different formula,http://www.microsemi.com/document-portal/doc_download/125192-lx27901-datasheet\[ f_{SW} \approx \frac{693000}{R_{C\_R} \cdot C_{C\_R}}\]

author: xrunner
author_rank: Super Contributor
timestamp: October 20, 2021, 12:31:03 pm
content: Look at the attached, seems top use a clearer equation for the calculations.

author: Brumby
author_rank: Unknown
timestamp: October 20, 2021, 12:32:35 pm
content: They look like power notation.For example, the denominator would be: (RC_R)0.94x (CC_R)0.91

author: ptricks
author_rank: Frequent Contributor
timestamp: October 20, 2021, 12:43:54 pm
content: Looks like the data sheet I had was the first version from 2011. They did change it in 2012 which is much easier to understand. Thanks didn't know about that.
Raised / Elevated SMT inductors -- hard to find? - Page 1
Forum section: electronics / general

author: smoothVTer
author_rank: Regular Contributor
timestamp: January 24, 2018, 03:35:41 pm
content: Wondering if anybody here has designed with elevated SMT inductors ... the kind that have tabs for elevating the inductor body above the Dc/Dc controller chip, in order to reduce the X/Y footprint of the total system.I am having trouble finding suitable sources for these inductors. Are these usually custom made?TI app notehttps://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0ahUKEwjThuD39fDYAhXoQd8KHSMyDwcQFggpMAA&url=http%3A%2F%2Fwww.ti.com%2Fanalog%2Fdocs%2Flitabsmultiplefilelist.tsp%3FliteratureNumber%3Dslva764%26docCategoryId%3D1%26familyId%3D751&usg=AOvVaw20rdyIYzSzJEeFDswc-LEvmentions these inductors are custom-made.I already know about Coilcraft's XAR7030 series off-the-shelf solution, but there are about 2.5x too wide in the X/Y to fit onto my PCB. I'm looking for off-the-shelf solutions with a footprint of around 3mm x 3mm maximum.Anybody know where to find such parts?

author: Gribo
author_rank: Frequent Contributor
timestamp: January 25, 2018, 05:05:38 pm
content: While I can't find it now, Murata had capacitors with raised tabs. I would also check with other manufacturers (Wurth, Sumida, Vishay, TDK) if they plan to introduce a similar product (Coilcraft published it in late 2017).

author: dciliske
author_rank: Newbie
timestamp: October 15, 2021, 08:33:37 am
content: Just so anyone who happens to go searching the web for this like me: It looks like it got patented, and I guess folks decided it wasn't worth licensing.https://portal.unifiedpatents.com/patents/patent/WO-2015074247-A1https://portal.unifiedpatents.com/patents/patent/CN-102592781-AActually... there's a lot of patents for this, so, idk. But I guess that's my theory on this anyways.
Scam with faked DHL notification (Germany) - Page 1
Forum section: electronics / general

author: Le_Bassiste
author_rank: Frequent Contributor
timestamp: October 13, 2021, 07:01:26 am
content: whoa. was waiting for a JLCPCB parcel from shenzhen and almost fell for it.

author: Refrigerator
author_rank: Super Contributor
timestamp: October 13, 2021, 11:19:33 am
content: dungdungMy german is a bit rusty, are they asking for you to pay up some import fee?

author: gcewing
author_rank: Regular Contributor
timestamp: October 13, 2021, 11:31:09 am
content: They're probably hoping you'll klicken on the Login link so they can steal your credentials.

author: Le_Bassiste
author_rank: Frequent Contributor
timestamp: October 13, 2021, 11:31:32 am
content: Quote from: Refrigerator on October 13, 2021, 11:19:33 amyes, they said that parcel was delivered to nearby post office (rather than to me directly), and that i had to pay customs EUR 1.99 on their provided weblink prior to getting my package cleared. and yes, dungdung rang the bell(what almost sold me was the fact that i had a similar DHL email before (for another JLCPCB delivery) where DHL required me to pay customs beforehand via weblink, or cash upon delivery. that email wasn't scam, though.)

author: daqq
author_rank: Super Contributor
timestamp: October 14, 2021, 06:56:09 pm
content: I once got this SPAM, also looked very legit:Quote

author: Benta
author_rank: Super Contributor
timestamp: October 14, 2021, 07:57:27 pm
content: The kicker is the sender email address. Looks very trustworthy... or?
Some unusual components - Page 1
Forum section: electronics / general

author: msuffidy
author_rank: Frequent Contributor
timestamp: October 13, 2021, 11:43:11 pm
content: There are 2 sets of components I think are rather odd on this inverter board I got out of an older LG Flattron monitor. I put red asterisks on the components. Isn't that a lot of transformer coils? And the other things look like metal blocks for what reason?

author: msuffidy
author_rank: Frequent Contributor
timestamp: October 13, 2021, 11:49:24 pm
content: The backlight was sort of flickering darker and I thought maybe it was some cold solder joint, but I decided I was through with this monitor as it took a lot of dings in the past switching the caps. Some data pointed to maybe a connection issue with the backlight connectors on the inverter board. There were a lot of fluxy joints.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: October 14, 2021, 12:05:21 am
content: What's the designator? HS? Guessing there are SMD transistors on the bottom and those are heatsinks.The section is a CCFL driver, several evidently (big enough screen to need them, it seems). The transformer is wound in multiple sections to reduce capacitance between its many (thousands?) of turns, allowing the generation of high voltage at high frequencies. It operates in a resonant mode, most likely a traditional two-transistor ZVS (Baxandall) oscillator.Tim

author: amyk
author_rank: Super Contributor
timestamp: October 14, 2021, 12:13:19 am
content: The multiple-section coils also help with isolation, since their output voltage is very high.

author: shakalnokturn
author_rank: Super Contributor
timestamp: October 14, 2021, 09:16:32 am
content: Quote from: T3sl4co1l on October 14, 2021, 12:05:21 amAlthough it will have some effect on inter-winding parasitic capacitance I'd expect that the separate sections on the HV secondary are to prevent wire insulation breakdown by keeping the voltage between layers low enough.While Baxandall oscillators are sometimes seen on small single CCFL inverters, most of the time large screens are driven by dedicated oscillator / control IC's that allow for PWM dimming and monitoring CCFL condition.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: October 14, 2021, 05:22:48 pm
content: Indeed, which seems to be the case here (the nearby DIP IC).Hm, also there's six transformers but only four heatsinks, seems likely they're driven in parallel on the primary side, and that would make the job easier for a management chip too. Hm, I wonder if they're doing full bridge then, and varying frequency with PWM (phase shift PWM even?) or frequency.Have also seen controllers (usually amounting to a simple buck converter or even plain fixed PWM into the supply inductor) used with oscillators. Doubt that's the case here.Tim
Warped QMP Workbench - Page 1
Forum section: electronics / general

author: veedub565
author_rank: Frequent Contributor
timestamp: October 12, 2021, 07:37:15 pm
content: I recently bought a used QMP workbench, it is about 3yrs old. It's 1800mm x 900mm with a Neostat ESD surface.https://www.qmp.uk.com/square-tube-esd-workbenches.htmlThing is its warped, or more specifically the top is cupped. Front to back over a distance of 900mm it dips in the middle by about 8mm. Which is enough to be noticeable.Its also doing the same width ways too, but the metal frame is holding it to a degree.It seems a bit of a bad design really. There's nothing in the centre of the worktop to support it and prevent it dipping in the middle. The metal bars going width ways aren't box section steel. More like a C shape, and the worktop is bending it out of shape as it curls up. All 4 corners are lifting up. The only box section part is the leg frames and they aren't even attached to the worktop.I'm assuming its been in a damp environment. The bottom has absorbed more moisture than the rubberised top, and thats why its warped. I've got an old cantilever Kaymar bench though, same size, and that has been in a cold damp shed for 20yrs... no problem at all.The amount QMP charge for these workbenches, the engineering is pretty poor really.
Made a Python focused DAQ - Now I'm Selling the Business - Page 1
Forum section: electronics / general

author: seanEE
author_rank: Contributor
timestamp: October 14, 2021, 03:05:04 am
content: I made a python API for a DAQ and paired a custom designed testing module with it to make setting up test rigs faster.https://www.magicdaq.com/https://magicdaq.github.io/magicdaq_docs/I sent a free one to Dave, he seems to have liked it? ( time 53:54):It turned into a profitable little business. Data:https://drive.google.com/drive/folders/1esIJEpCJzSxMCJqZNe3qS0_4YCn8OGEA?usp=sharingI'd like to move on to my next project now, so I'm looking for someone to acquire the business and take over shipping the product to customers.https://www.sideprojectors.com/project/24649/magicdaqFeel free to contact me at support@magicdaq.com if you are interested.

author: thm_w
author_rank: Super Contributor
timestamp: October 14, 2021, 08:56:40 pm
content: Didn't realize digikey had them, searching for "magic daq" gives no results. Seems the listing is removed:https://www.digikey.ca/en/supplier-centers/magicdaqDid you have any returns?

author: 2N3055
author_rank: Super Contributor
timestamp: October 15, 2021, 11:22:37 am
content: So is it isolated or not?

author: voltsandjolts
author_rank: Unknown
timestamp: October 15, 2021, 12:27:15 pm
content: Cross-reference:https://www.eevblog.com/forum/projects/2020-lockdown-made-a-general-purpose-pcb-test-jig-and-python-powered-usb-daq/Quote from: seanEE on September 25, 2020, 05:04:33 pmJust so we are all clear on what is for sale here;It's off-the-shelf Chinese DAQ hardware along with your Python API (how many LoC?) and a per-device calibration, which locks the user into your product line.Is that a fair summary?

author: thm_w
author_rank: Super Contributor
timestamp: October 15, 2021, 09:25:29 pm
content: Quote from: 2N3055 on October 15, 2021, 11:22:37 amIt is not, could tell from the photos.Probably easy enough to add a USB isolator for $10 though.

author: 2N3055
author_rank: Super Contributor
timestamp: October 15, 2021, 10:15:11 pm
content: Quote from: thm_w on October 15, 2021, 09:25:29 pmI can see that. I was asking for an admission. It says "isolated" on a box. It isn't. What else is made up ?

author: thm_w
author_rank: Super Contributor
timestamp: October 15, 2021, 10:33:39 pm
content: Quote from: 2N3055 on October 15, 2021, 10:15:11 pmFor some reason I thought OP was a software engineer, and the oversight was understandable. But yeah, EE... not great to claim.Anyway $5k seems reasonable enough.

author: Benta
author_rank: Super Contributor
timestamp: October 15, 2021, 11:07:01 pm
content: Quote from: thm_w on October 15, 2021, 10:33:39 pm"I have a special offer for you... but only because you're my friend.. hehe... A complete Eiffel Tower! Really. We just need to talk about price and shipping. But I'm certain that we can find an agreement."Honestly, buying cheap Chinese HW and slathering some code on top (I don't care if it's Python, Cobol, Pascal or assembler) is enough to try selling it as a business?Wow!(running away screaming to evade the creditors)
Uni-t UN210e OLD TEST DATE - Page 1
Forum section: electronics / general

author: rorymax
author_rank: Contributor
timestamp: October 09, 2021, 07:54:49 pm
content: Today I just received my order of a Uni-T UT210e.A few things caught my attention.1. The test date for the device isApril 2020.2. 2 x AA batteries were already fitted, both are showing 1.56v.3. On the rear of the device there is no serial number sticker in the area that is designated for said sticker.Cursory testing ofsomefunctions results are OK.£42.00 from Amazon, would anything I've mentioned cause any bells to ring for any of you folks?

author: PlainName
author_rank: Super Contributor
timestamp: October 10, 2021, 06:19:36 pm
content: Things tend to get made in bulk then dribble out of the stockroom over time, so the manufacturing date isn't too important. Pre-fitted batteries are fine, but should perhaps have some isolation tab to remove so they're not powering anything until you open the box.I just checked my 210e and that also has no serial number sticker. AFAIA it is a pukka item (and works well). I don't think there is likely to be anything dodgy about yours.

author: armandine2
author_rank: Frequent Contributor
timestamp: October 10, 2021, 07:23:50 pm
content: The other month my new Kewtech KEW1052 arrived. The certificate of calibration was dated 29,Jan,2014 - someone must have been superstitious, I guess.
Philco Radio Phono signal - Page 1
Forum section: electronics / general

author: Ground_Loop
author_rank: Frequent Contributor
timestamp: October 10, 2021, 02:48:55 pm
content: I'm bringing an old Philco radio/record player back to life and have a question about the phono signal. Boxed in red below is the phono signal going into the RF section. I assume this is done to avoid a dedicated amplifier for the low level signal. What I don't see is how the audio portion is mixed to a proper IF to be selected out. Please explain. It looks like a neat trick.

author: SeanB
author_rank: Super Contributor
timestamp: October 10, 2021, 05:40:09 pm
content: It is not fed into the diode demodulator, but instead amplified as AF audio by the IF strip, with the transformers Z1 and Z2 being used as interstage coupling transformers. The local oscillator is disabled when playing the phono side, instead being used to bias the 7A8 as audio amplifier. After a single stage of audio amplification, probably also with the transformers providing the record de emphasis, the audio is fed direct to the volume control, with the 7C6 likely being used to provide a small amount of negative feedback to control gain and improve linearity, also likely doing more de emphasis to get a better approximation of the RIAA curve, and driving the 35L6GT power amplifier tube.

author: floobydust
author_rank: Super Contributor
timestamp: October 10, 2021, 06:37:51 pm
content: The trick is using the 7A8 as a simple triode. In Phono mode, the LO is disabled and audio bypasses the IF, gets coupled into switch WS1 (near test point A) at the volume control.So they're using the 7A8 for some gain, grid2 at pin 3 as a plate and switching in a cathode resistor for bias.The turntable's cartridge, withoctalsLoctals it seems to be low output in the era. Later decades you would see high output ceramic cartridge used.

author: Ground_Loop
author_rank: Frequent Contributor
timestamp: October 10, 2021, 07:41:07 pm
content: Thanks for the explanation. I'm going to inject some test signals when I get it back up. I'm curious how much amplification that first stage provides. I'm by no means a tube expert, but I never would have thought one of the grids could be used as a plate.

author: bob91343
author_rank: Super Contributor
timestamp: October 11, 2021, 03:21:03 am
content: It does seem that T1 acts as an audio transformer. Very strange circuit.

author: floobydust
author_rank: Super Contributor
timestamp: October 11, 2021, 03:57:22 am
content: 7A8is an "Octode Converter" grid #2 is the oscillator plate. I'd have to look inside one to see what they are doing, if all elements are inline.T1 couldn't do anything with audio, it's in the LO tank circuit providing feedback from grid #2 to grid #1. But somebody figured with a complicated switch you could turn the LO and Mixer stage into an audio amp and voila it can play records too. Features were a big factor back then, so people banged their heads a lot to add one without extra parts/tubes.
moronitude++ - Page 1
Forum section: electronics / general

author: eti
author_rank: Super Contributor
timestamp: October 10, 2021, 10:47:20 pm
content: Ah, good old Cali-fool-nia - they just fail to grasp that THEY are the problem, NO amount of "tech" will fix ithttps://www.bbc.co.uk/news/av/stories-58841837This constant FORCING of childish, idiotic Sci-Fi naivety to come to pass, to bring to life the dopey fantasies of nerds, makes me cringe EVER so much

author: Nusa
author_rank: Super Contributor
timestamp: October 10, 2021, 10:58:48 pm
content: You do realize that deliberately trying to make things political is against the written rules here? The linked video doesn't do that, that's you doing it.Also, this forum does have a robotics and automation section.

author: xrunner
author_rank: Super Contributor
timestamp: October 10, 2021, 11:01:48 pm
content: I think it's time to call our own "robo cop" ...

author: eti
author_rank: Super Contributor
timestamp: October 10, 2021, 11:03:05 pm
content: Gosh you lot are easily wound up. Calm down.

author: Benta
author_rank: Super Contributor
timestamp: October 10, 2021, 11:09:31 pm
content: Never mind, @eti has "taken back control" with empty supermarkets and gas stations and has "calmed down". Wonderful.

author: eti
author_rank: Super Contributor
timestamp: October 10, 2021, 11:12:27 pm
content: Quote from: Benta on October 10, 2021, 11:09:31 pmIs that obscure Germanic humour, or just plain ignorant bigotry toward your fellow man? I could, and would make a few idiotic, generalising comments about German life, but won't lower myself to that, because it isn't a kind thing to do, is it.

author: Ground_Loop
author_rank: Frequent Contributor
timestamp: October 11, 2021, 12:39:26 am
content: My employer recently offered to relocate me from Atlanta to San Diego. Having lived in Cali at one time and also enjoyed the simple freedom of the SE US, I politely, but emphatically declined.

author: tooki
author_rank: Super Contributor
timestamp: October 11, 2021, 12:50:11 am
content: Quote from: eti on October 10, 2021, 11:12:27 pmIt’s been made abundantly clear to you that this forum does not appreciate this kind of deliberate shit-stirring (neither the original post, nor the shitty jab at Benta). You’ve been warned to not start political posts. So would you kindly bugger off and be quiet?!?

author: eti
author_rank: Super Contributor
timestamp: October 11, 2021, 12:51:39 am
content: Quote from: tooki on October 11, 2021, 12:50:11 amYour understanding and graceful nature are a breath of fresh air. 😏You will go far. You’re very sure of yourself (and exceptionally crass), from behind the safety of your screen, and somewhat predictable in your tediously blind attempt to solve what you see as a “problem”, by pouring vulgarity and vitriol.The virtues are all yours, it appears you think.

author: EEVblog
author_rank: Unknown
timestamp: October 11, 2021, 01:00:14 am
content: ETI, you have been warned previously about start off-topic posts. Please don't do this again.
Trevor Noah comments on "Right" To Repair and planned obsolescence - Page 1
Forum section: electronics / general

author: cdev
author_rank: Super Contributor
timestamp: October 21, 2021, 11:25:12 pm
content: This is actually a very good exploration of the issue.. What do you think?

author: eti
author_rank: Super Contributor
timestamp: October 22, 2021, 07:46:14 pm
content: What do I think? I think a more informed video is needed - here:
lm317 vs lm217 what is the difference? - Page 1
Forum section: electronics / general

author: innkeeper
author_rank: Unknown
timestamp: October 08, 2021, 06:20:13 am
content: lm317 vs lm217 what is the difference?

author: Kleinstein
author_rank: Super Contributor
timestamp: October 08, 2021, 07:10:52 am
content: Much of the LM3xx, LM2xx and LM1xx series are parts specified for different temperature ranges. The LM3xx are the cheaper ones for the more normal temperature range. The LM1xx are for the more milittary temperature range. The actual silicon may the the same. Differences are more in testing and the case.

author: tooki
author_rank: Super Contributor
timestamp: October 08, 2021, 09:28:32 am
content: Quote from: innkeeper on October 08, 2021, 06:20:13 amYou know that there are these things called “datasheets” that will tell you?Admittedly, with some parts and some datasheets it’s extremely hard to spot the differences, and I have on occasion encountered parts where only a query to the manufacturer revealed the difference.But in this case:https://www.st.com/resource/en/datasheet/lm217.pdf

author: innkeeper
author_rank: Unknown
timestamp: October 08, 2021, 06:52:47 pm
content: Quote from: tooki on October 08, 2021, 09:28:32 amyou really think id not have asked before looking over the datasheets?

author: Benta
author_rank: Super Contributor
timestamp: October 08, 2021, 08:21:55 pm
content: Quote from: innkeeper on October 08, 2021, 06:52:47 pm@innkeeper, I'm with you here. The TI datasheet only mentions LM317.@tooki, try to keep your mood under control.Historically, National Semiconductor (now TI) parts were named LM1xx, LM2xx(x) and LM3xx for military, automotive and consumer temperature ranges.Otherwise, there's no difference.

author: magic
author_rank: Super Contributor
timestamp: October 08, 2021, 09:26:38 pm
content: There can be differences and there is at least one fairly well known difference in worst case specifications between 117/217 and 317RTFM is recommended on case-by-case basis.

author: Kleinstein
author_rank: Super Contributor
timestamp: October 08, 2021, 09:43:37 pm
content: The temperature range is a point one rarely looks at for hobby use. Without knowing where to looks it is not easy to spot the difference. Quite often there is a single datasheet for LM1xx, LM2xx and LM3xx - that makes it usually easier.

author: tooki
author_rank: Super Contributor
timestamp: October 09, 2021, 01:33:13 pm
content: Quote from: innkeeper on October 08, 2021, 06:52:47 pmYes, since you didn’t say you’d looked at the datasheet, and wrote only a very terse question with no info about what you have and haven’t discovered.Unfortunately, it is not at all uncommon for people to ask the forum first, before doing any legwork of their own. Super short, open-ended questions like yours are typical for the “I want others to do my homework for me” inquirers.
More consolidation: Renesas buys Dialog - Page 1
Forum section: electronics / general

author: tszaboo
author_rank: Super Contributor
timestamp: October 08, 2021, 08:53:13 am
content: https://www.renesas.com/us/en/about/press-room/renesas-and-dialog-semiconductor-announce-conclusion-final-regulatory-review-and-expected-closing"Renesas and Dialog Semiconductor Announce Conclusion of Final Regulatory Review and the Expected Closing Date for Renesas’ Proposed Acquisition of Dialog Semiconductor"In non-weasel talk this translates to "Renesas buys Dialog". Look at that announcement, half of it is a disclaimer for the lawyers on the bottom.I personally wouldn't care. Dialog and Renesas both doesn't talk to small players. Renesas doesn't even bother releasing full info on parts without NDA. But Dialog bought Adesto few months back, and they were the primary source of low power flash memories. At least I could clear up with the distributor, that nothing really will change, and I get parts when they have it. Sigh.

author: westfw
author_rank: Super Contributor
timestamp: October 09, 2021, 12:03:24 am
content: I thought Dialog's sales/support of the GreenPack mini-FPGAs was pretty hobbyist/small user friendly.Although that may have been a holdover from the Silego days.
Why would you lower the input impedance to a pre-amp? - Page 1
Forum section: electronics / general

author: Karl
author_rank: Newbie
timestamp: October 08, 2021, 03:46:55 am
content: Hi,I've been working on an old Roland mixer/PA combo and I've just noticed something that has me scratching my head.The mixer has a total of eight channels - each channel has an input impedance of 10kohms. Someone in the past has added a 2.2kohm resistor across each of the inputs which, in parallel with the 10k input impedance reduces the input impedance to about 1.8kohms.My question is why would someone do this? For general source connectivity to a preamplifier we require a low source impedance while the input impedance to the preamplifier needs to be high for voltage sources. In this case the sources would likely be dynamic microphones or outputs from electric guitars - these have an output voltage of 20 - 100 millivolts or thereabouts (peak to peak). The preamplifier specification for these inputs is -50dBm to -10dBm.The only reason I can think why this was done was to use these inputs as line in inputs with a higher input voltage. Line out signals are generally about 1.0 volts, but for this to work, if my understanding is correct, then the source impedance would also be quite high (say 600 ohms) in order to see an effective reduction of voltage due to the combination of the source and input impedances.If the source impedance is low (say less than 100 ohms) then there would be little reduction of the source voltage and the lower input impedance wouldn't have much effect.I'm not sure if my thinking on this is correct so any advice would be appreciated.Regards,Karl

author: bdunham7
author_rank: Super Contributor
timestamp: October 08, 2021, 03:58:13 am
content: Your thinking appears sound and it may well have been an ad-hoc modification to interface with an older system of some type that did have 600 ohm outputs, possibly transformers.

author: bob91343
author_rank: Super Contributor
timestamp: October 08, 2021, 04:03:27 am
content: Perhaps to control noise. Hum pickup from a high impedance source for instance. Or even rf.