hybridfree/eevblog-posts huggingface dataset:
Wanted: Source for really good quality croc clips - Page 1
Forum section: electronics / general

author: Psi
author_rank: Super Contributor
timestamp: June 26, 2020, 11:59:17 am
content: Can anyone recommend some good quality crocodile clips. I'm sick of having crap clip leadsI have plenty of good quality silicone wire in various colors so can make my own clip leads up to various lengths.I just need a source of known good quality croc clips.I want them to feel like the pivot point has German ball bearings in it.

author: TimFox
author_rank: Super Contributor
timestamp: June 26, 2020, 02:36:07 pm
content: My favorites are from the US (Ohio) company Mueller Electrichttps://www.muellerelectric.com/products/category/ClipsNote that they distinguish between "alligator clips" (where the top and bottom edges are coplanar) and "crocodile clips" (where the top half fits inside the bottom half when closed), following reptile anatomy.They make a huge range of clips, including miniature alligator and crocodile clips, large battery charging clips, and Kelvin clips.The ones you want are probably on this pagehttps://www.muellerelectric.com/products/category/Clips?opts=171

author: jogri
author_rank: Frequent Contributor
timestamp: June 26, 2020, 03:09:06 pm
content: I can recommend SKS Hirschmann, i have a bunch of their AK2 clips and they are good even for thin wires. Farnell and RS should have them, but i don't know if they have clips that you can solder your own wires on (mine have 4mm banana plugs).

author: floobydust
author_rank: Super Contributor
timestamp: June 26, 2020, 05:49:20 pm
content: The absolute best test leads andalligator clipsI have used are from Japan byTeishin Electric.china is making cheap low quality ones that are terrible and have no place on a workbench unless you enjoy rechecking connections all the time.

author: rdl
author_rank: Super Contributor
timestamp: June 26, 2020, 06:45:17 pm
content: What do you use them for? The croc/alligator style seems big and clunky to me and look like something out of the 1950s or older. I much prefer the mini grabber and micro grabber types.

author: RandallMcRee
author_rank: Frequent Contributor
timestamp: June 26, 2020, 07:18:19 pm
content: The mueller electric ones are good.For less money, in a similar ballpark, is this knockoff from Adafruit:https://www.adafruit.com/product/3313

author: jpanhalt
author_rank: Super Contributor
timestamp: June 26, 2020, 07:37:55 pm
content: Ditto on Mueller.They are the only ones I buy.
840Uf 12 V closes value - Page 1
Forum section: electronics / general

author: jerryvb
author_rank: Newbie
timestamp: June 24, 2020, 11:07:29 pm
content: Hi I am fixing Tektronix scope 2215 at thepower supply the capacitor C972,C975 C985 are 840Uf 12V , that need to replace. I can't find the value much to this 3 caps.What do you think the best replacement value for this 3 capsemai me at jerryvcb@gmail.com

author: amyk
author_rank: Super Contributor
timestamp: June 25, 2020, 12:16:27 am
content: 820/16 is the closest standard value.

author: floobydust
author_rank: Super Contributor
timestamp: June 25, 2020, 01:51:26 am
content: I find modern electrolytic caps caps are low in value, close to their rated -20%, whereas the old Spragues were +100%/-10%.I useUnited Chemi-Con EKYB250ELL102MJ20S1,000uF 25V in Tek scopes.I recommend to upsize to 1,000uF as the 2235A did. I believe your power supply is similar, here is spreadsheet with those cap details and sizes, taken from thread:https://www.badcaps.net/forum/showthread.php?t=71125
Power Connectors - Overview - Page 1
Forum section: electronics / general

author: Homer J Simpson
author_rank: Super Contributor
timestamp: June 23, 2020, 11:43:44 pm
content: From: ShowMeCableshttps://www.youtube.com/user/showmecables/videos

author: Gyro
author_rank: Super Contributor
timestamp: June 24, 2020, 09:53:05 am
content: I like the NEMA 5-20... 'Err, what combination haven't we used yet?'
Any rotary encoder recommendations? - Page 1
Forum section: electronics / general

author: 741
author_rank: Frequent Contributor
timestamp: June 22, 2020, 08:27:43 am
content: The Bourns model feels smoother (almosttoosmooth in fact, so I feel it's not quite positive enough into the detents). The ebay type works fine, but is a bit heavy & grating. On balance, I prefer the 'feel' of the Bourns model.Partly this might be due to the fact that the Bourns is 24 detent (versus 20 detent for the other). I'm after something around 18-24 detent with centre-push and I wondered whether I could find a compromise price/performance wise between Bourns and 'generic'.Some of the eBay encoders have a thicker body, more like Bourns, maybe these would be better built?I'd be interested in photos (& links to) of encoders which cost less than Bourns but which have been tried & tested.

author: tooki
author_rank: Super Contributor
timestamp: June 22, 2020, 11:00:16 am
content: FYI, the Bourns encoder you show is the PEC11R, the thick model. The low-profile eBay one is a clone of Bourns’ low-profile model, the PEC11L.Given how cheap Bourns and Alps encoders are, and the problems with contact bounce that many people report with the eBay ones, I’m not sure it makes sense to go with eBay.

author: 741
author_rank: Frequent Contributor
timestamp: June 22, 2020, 01:11:12 pm
content: Thank you for that information about R vs. L. How do Alps compare I wonder?

author: tooki
author_rank: Super Contributor
timestamp: June 22, 2020, 04:06:39 pm
content: Quote from: 741 on June 22, 2020, 01:11:12 pmEssentially interchangeable. Their products are so similar, I suspect they have some kind of agreements to dual-source components. Both are top quality.

author: ebastler
author_rank: Super Contributor
timestamp: June 23, 2020, 05:15:47 pm
content: Quote from: 741 on June 22, 2020, 08:27:43 amI have used various detented ALPS encoders and never found them "too smooth". So maybe they are worth a try for you --ifthere is a real difference. The difference in our perceptions might also be simply subjective; and of course the diameter of the knob has a significant influence on the force you need to apply to overcome the detents.
Is Muscle Wire still a thing? - Page 1
Forum section: electronics / general

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: June 19, 2020, 11:31:46 pm
content: Cleaning my considerable stash of accumulated nonsense, I found a booklet with samples of Nitinol shape memory alloy.I remembered about 30 years ago I wanted to build a small robot arm and it never really worked. The enthusiasm and claims in the supplied booklet were a little over the top. Attaching the wire to an electrical contact and also strong mechanical joint was tricky. In any case it was slow to move.I see this wire is still being sold... but who uses it here? Or back then? I think it was a fad for a while in Radio-Electronics.

author: amyk
author_rank: Super Contributor
timestamp: June 20, 2020, 02:05:30 am
content: I believe it still has niche applications where the speed (or heat generation) is not a concern, and it has to fit in a tight space while providing a lot of force.

author: duak
author_rank: Super Contributor
timestamp: June 20, 2020, 02:17:17 am
content: I first heard it through the grapevine that Nitinol wires are used in Medical implants such as expanding stents. The stent is first located in the right place, then is heated electrically to flip it into the other state where it expands. Here's one link:https://www.materialstoday.com/biomaterials/articles/s1369702104002251/I got a few samples of various types. Neat stuff! IMHO, It takes a real inventor to synthesize a solution to a problem with atypical materials like Nitinol.

author: james_s
author_rank: Super Contributor
timestamp: June 20, 2020, 02:38:39 am
content: I remember seeing ads for the stuff in Nuts & Volts back in the 90s. I don't think I ever had any of it myself, it seemed like kind of a neat idea but not really all that useful.

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: June 20, 2020, 05:27:40 am
content: Quote from: james_s on June 20, 2020, 02:38:39 amYeah that's what I think too. However, it is a great lesson in marketing. The booklet is never-ending marketing hype, it's great.I guess I fell for it.Looks like the website is no longer in business.http://www.musclewires.com/

author: shakalnokturn
author_rank: Super Contributor
timestamp: June 21, 2020, 08:11:49 pm
content: Used in the Omnipod disposable insulin pump.https://arxiv.org/pdf/1709.06026.pdf

author: NiHaoMike
author_rank: Super Contributor
timestamp: June 21, 2020, 08:27:43 pm
content: Quote from: shakalnokturn on June 21, 2020, 08:11:49 pmTeardown video:

author: ebclr
author_rank: Super Contributor
timestamp: June 22, 2020, 11:28:34 am
content: https://www.kelloggsresearchlabs.com/
Tear down of an Einstein monoblock studio strobe - Page 1
Forum section: electronics / general

author: mesonnaise
author_rank: Newbie
timestamp: June 21, 2020, 07:49:08 am
content: Today I had to replace an the old fans in my studio strobes. While dismantling them I was reminded of Dave's tear downs on the YouTube channel, so I decided to document all the boards to share with everyone.The album contains front and back photos of each board, along with the full assembly without the case.https://imgur.com/a/QC3Fe9S

author: NiHaoMike
author_rank: Super Contributor
timestamp: June 21, 2020, 01:34:17 pm
content: What surprises me are the "Richey" caps amongst the well known, higher quality brands. Does the fan run all the time or only when the flash has been fired several times in a row?

author: mesonnaise
author_rank: Newbie
timestamp: June 21, 2020, 07:34:37 pm
content: The cap selection is because of the tight price point. If the capacitor wasn't part of the charge pump or main storage a cheaper part was used.The fan runs constantly. The manufacture did create a new firmware to cycle the fan when the SCRs start to heat up. The problem is I can't find a compatible micro SD card to do the update.Everything on the left side is for the modeling lamp and charge pump. The right is the dc to dc converter for the digital control.

author: NiHaoMike
author_rank: Super Contributor
timestamp: June 21, 2020, 07:52:54 pm
content: Quote from: mesonnaise on June 21, 2020, 07:34:37 pmIf it only accepts the older SD cards and not SDHC, look for a 2GB card. It's good to keep a few 2GB and under SD cards for that reason.

author: mesonnaise
author_rank: Newbie
timestamp: June 21, 2020, 09:35:22 pm
content: I wasn't having a problem finding first gen 2GB SD cards. Finding a first gen micro SD card is the problem.

author: tom66
author_rank: Super Contributor
timestamp: June 21, 2020, 09:56:08 pm
content: The problem is microSD launched in 2005 and SDHC launched in 2006/2007. So there is a very short time span between when the older technology was common with microSD, and when it will have been less common and then eventually obsoleted altogether.

author: NiHaoMike
author_rank: Super Contributor
timestamp: June 21, 2020, 10:32:44 pm
content: Quote from: mesonnaise on June 21, 2020, 09:35:22 pmMight want to try a micro SD to full size SD adapter (opposite of the usual type), once commonly used with Raspberry Pi.

author: mesonnaise
author_rank: Newbie
timestamp: June 22, 2020, 12:14:56 am
content: Quote from: NiHaoMike on June 21, 2020, 10:32:44 pmI'll see if I can hunt one down that fits.
Arduino Mega as webserver for PLCs (modbus) - Page 1
Forum section: electronics / general

author: machinebyte
author_rank: Newbie
timestamp: June 20, 2020, 03:30:59 pm
content: HelloI like automatization and also professionally do similary things. Lately I have made a simply web server based on Arduino Mega. Mega act also as master in Modbus net and its aim is to collect and show results/datas on web page received from slave devices in Modbus net. Here you can watch this workbut i'm interesting also for different platform. Currently (in my spare time) I'm developing some feature for my robotic arm (also on my channel) based on OpenCV and Lazarus - want to make its to follow the object. If sameone share similar interests it would be nice to talk to.Best regards,
scanners and printer freebies at the local tip. - Page 1
Forum section: electronics / general

author: cleanworkbench
author_rank: Regular Contributor
timestamp: June 19, 2020, 10:04:45 am
content: I,m looking out for a scanner and printer for PCB board making , i already have sourced two from the local tip. a HP C4480 and a Samsung C410W . I am looking to do PCB artwork.The HP 4480 is an inkjet and also has a nice flat scanner that could be used for such purpose as copying artwork from old electronic magazines etc putting into a art program and readjusting for scale then printing.The Samsung is a Laser printer only , no scanner.Question is , what is best for home PCB production, Inkjet or Laser. there seems to be people using both ?.I also want to scan in old photo negs and archive them. so the HP4480 could be dual use if the Dpi is up to it !!!.There is no software with either these two units so where is the best place to source that .How do i trick out the HP4480 inkjet sensors to just use the scanner ie disable the printing capability?.Any help appreciated many thanks.
Deal on bundle of the Art of Electronics books - Amazon - Page 1
Forum section: electronics / general

author: norks
author_rank: Contributor
timestamp: June 19, 2020, 08:38:53 pm
content: Amazon has a promo on select books, games, and other media right now. 3 for the price of 2, and the 3 Art of Electronics books are included. So You can buy AoE 3rd Ed, student manual, and get the X-chapters free (since it's the cheapest of the 3).Sorry if this was already posted, didn't see it elsewhere.

author: WattsThat
author_rank: Frequent Contributor
timestamp: June 19, 2020, 09:11:35 pm
content: Thank you! I’ve been needing an excuse to buy the set. One free + Father’s Day. Done deal.
What Equipment Has Your Pet Messed Up? - Page 1
Forum section: electronics / general

author: Cyberdragon
author_rank: Super Contributor
timestamp: June 19, 2020, 03:26:45 am
content: My very elderly cat likes to sit on strange things and in strange places.Today she sat on my silver Paco S-55 (which was under a table with other stuff) and puked profusely on the front right corner, running all down the side and front of the panel all in the knobs and binding posts and then onto the carpet. It was a bitch to get out from where it was without making more of a mess on the carpet. I managed to get it out onto a towel and scrub it with paper towls, WD-40, and a toothbrush. But it's gonna stink of the combination of spray and puke for a while so it's still sitting out to dry.What has your pet messed on, chewed on, knocked down, exc?

author: tooki
author_rank: Super Contributor
timestamp: June 19, 2020, 05:32:22 am
content: My home theater speakers still have minor damage to the speaker grilles from our kitten 15 years ago using them as a scratching post. 😂Some day I should get around to putting new speaker cloth on, I suppose.

author: mathsquid
author_rank: Frequent Contributor
timestamp: June 19, 2020, 07:04:30 pm
content: I used to do a bit of amateur astronomy. I had a cheap telescope, trained on Jupiter or Saturn, and the planet kept going out of view (and not just because of the rotation of the earth). I was trying to figure out what my problem was when I look down and see my cat rubbing his face against one of the tripod legs.Cats make everything more fun!

author: Photoman
author_rank: Regular Contributor
timestamp: June 20, 2020, 04:33:03 am
content: Years ago our rabbit ate an entire 12" sub woofer cone! He ate the paper part and the rubber part as well.This was in a speaker cabinet my father and I made from scratch.Also a rabbit sized hole in a leather couch, the foam stuffing and some of the wood.We kinda expected yellow foam rabbit sized poop but nothing. To this day I still wonder where it all went.A PBX telephone line, the kind that has enough voltage and current to throw you. He didn’t seem to mind it at all.Same when he at a lamp cord that was still plugged in.How the heck do they survive that?Then a DMM test lead. I should have thanked him for that one.I didn’t know at the time it was a crappy lead until I saw how little copper was in it.He did nip the DMM as well but it wasn’t to his liking. Just stomped on it and hopped away.

author: vk6zgo
author_rank: Super Contributor
timestamp: June 20, 2020, 05:35:57 am
content: My previous cat very much liked the silicon rubber lead on my Weller WTCP iron.She bit it in half, the cut from her sharp little teeth looking like it had been done with sidecutters!When I was a kid, we were "off grid".Our domestic radio was a large tube portable with two big flattish knobs on the top.Our cat loved sleeping on top of it, & often, whilst moving around getting comfortable, would turn the volume up or down, or detune the thing, so we got used to weird sounds from the radio when she was around.
When was this manufactured? - Page 1
Forum section: electronics / general

author: nardev
author_rank: Unknown
timestamp: June 18, 2020, 08:17:34 pm
content: I remember this as a "toy" back in 1990-1991 in Yugoslavia. But i'm just wondering what could be the manufacturing year, i'm wondering if this number can give any clue: 8818

author: duckduck
author_rank: Frequent Contributor
timestamp: June 18, 2020, 08:22:55 pm
content: PCB designed in week 18 of 1988?
We're doomed! - Page 1
Forum section: electronics / general

author: nfmax
author_rank: Super Contributor
timestamp: June 18, 2020, 03:30:16 pm
content: Go to the Farnell UK website, click 'Resources' and 'Brexit Preparation Update', and see what you get:https://www.element14.com/news/brexit-update-for-our-eu-and-uk-customers-march-2019?_ga=2.61664366.318086491.1592220200-1251838165.1592220200

author: noreply
author_rank: Frequent Contributor
timestamp: June 18, 2020, 04:06:49 pm
content: We were DOOMED as soon as BORIS got 86 seat majority

author: TimFox
author_rank: Super Contributor
timestamp: June 18, 2020, 09:09:49 pm
content: It must have really scary (or maybe really accurate?), since the linked page has been removed.

author: Psi
author_rank: Super Contributor
timestamp: June 18, 2020, 10:13:48 pm
content: What did it say?
Heatsink to PCB mounting thingies (pins?) - Page 1
Forum section: electronics / general

author: Axk
author_rank: Regular Contributor
timestamp: June 18, 2020, 08:14:20 pm
content: For mounting vertical heatsinks like the below (I suppose it has threaded holes for the PCB mounting) what's the name of the thingies that you would mount it to the board with?Should I just use M3 crews?Or is there something special-purpose with an M3 thread on one end and that can be inserted into PCB holes and soldered like a component pin?

author: daqq
author_rank: Super Contributor
timestamp: June 18, 2020, 08:24:11 pm
content: You can use self tapping screws into the heatsink.There are solderable threads ( such as thesehttps://sk.farnell.com/wurth-elektronik/9774015151r/spacer-smt-round-steel-m2-5-1/dp/2497591).Or create a thread inside of the heatsink.

author: rdl
author_rank: Super Contributor
timestamp: June 18, 2020, 08:47:39 pm
content: I've seen clip on pins for folded metal heat sinks. The smaller extruded types will often have holes for press fit pins. In both cases the pins get soldered to the board. You may have to go to the manufacturer for the correct part.

author: TimFox
author_rank: Super Contributor
timestamp: June 18, 2020, 09:07:00 pm
content: Does "3*3" mean three 3-mm holes, or three M3-tapped holes?

author: Benta
author_rank: Super Contributor
timestamp: June 18, 2020, 10:02:36 pm
content: M3 or self-tapping? It doesn't matter. On a heatsink that size, you need screws, forget soldering. I'd have expected M4 or even M5, actually.

author: nctnico
author_rank: Super Contributor
timestamp: June 18, 2020, 10:07:27 pm
content: Solderable nuts is the term but the heatsink is rather large to be held by solderably nuts. You'll need to mount the heatsink to a chassis or casing.
Product innovation...need funding to  put it together. - Page 1
Forum section: electronics / general

author: ocset
author_rank: Super Contributor
timestamp: June 17, 2020, 03:16:29 pm
content: Hi,I have developed an electronics product (never disclosed on this or any forum). I tried to get funding in UK but cannot.In London, a lorry drove past me several times with a big sign “Startups, keep calm and move to Berlin”.As such, I would like to present my idea to the German innovation authorities. Do you know who I could write/email to?

author: IanB
author_rank: Super Contributor
timestamp: June 17, 2020, 03:28:51 pm
content: How are you doing so far with:- business plan?- market research?- prototypes with user feedback?- IP protection?- management partners?Clearly all of these things will be important to potential investors.

author: Koen
author_rank: Frequent Contributor
timestamp: June 17, 2020, 03:51:12 pm
content: Good old treez

author: ocset
author_rank: Super Contributor
timestamp: June 17, 2020, 04:37:58 pm
content: Danke Schon. Ich möchte mein Produkt zum Nutzen Deutschlands entwickeln.Um ehrlich zu sein, ist es bereits entwickelt.Ich muss es nur zusammenstellen.

author: pardo-bsso
author_rank: Frequent Contributor
timestamp: June 18, 2020, 01:44:06 pm
content: So how much money and other resources do you need to get this going?

author: nctnico
author_rank: Super Contributor
timestamp: June 18, 2020, 01:54:42 pm
content: Kickstarter?

author: ocset
author_rank: Super Contributor
timestamp: June 18, 2020, 02:55:10 pm
content: QuoteThanks, in the first instance, just one month and a small room, so i could make a prototype. Then the true worth of the product will be evident.I can pay for components and test kit.Help with some money for ESD matting would be appreciated though.Also, help with a second hand isolated variable AC source 0VAC to 300VAC, and a Diff Probe (Eg Testec TT-SI 9001), and a Xintai HT-04 thermal cam would be useful.So approx £500 for these bits of kit, but could be cheaper finding second hand.In the first instance, i could do without these though.

author: nctnico
author_rank: Super Contributor
timestamp: June 18, 2020, 03:03:27 pm
content: Quote from: treez on June 18, 2020, 02:55:10 pmNope. That is a recipe for a disaster. First find the customers then design the product. You'll see funding will be easy once you have the customers.

author: tom66
author_rank: Super Contributor
timestamp: June 18, 2020, 03:17:14 pm
content: If you will struggle to put £500 of your own cash towards an idea then many investors will not take you seriously. Be prepared to spend thousands of pounds of your own cash to get an idea off the ground which may well go nowhere.Inventing is hard. Those who convince investors to invest get an easier life but then need to keep the investors happy which comes with its own set of problems.
Here's some light-hearted music inspired by electronics subjects - Page 1
Forum section: electronics / general

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: June 17, 2020, 01:20:24 am
content: Well of course I found this while looking for Nuvistor information, what a surprise.I love this kinda Jean-Jacques Perrey vibe.

author: John B
author_rank: Frequent Contributor
timestamp: June 17, 2020, 08:17:35 am
content: The style sounds like a lot of the video game tracker music that was around in the 1990's and early 2000's, but an evolved into a modern DAW with better synthesis and effects.
JLC PCB site - Page 1
Forum section: electronics / general

author: calexanian
author_rank: Super Contributor
timestamp: January 08, 2020, 07:42:47 pm
content: Anybody else notice the JLC site running very slow and crashing?

author: calexanian
author_rank: Super Contributor
timestamp: January 09, 2020, 03:21:01 pm
content: It’s back up. Got a non specific message from them but now appears to be working again.

author: calexanian
author_rank: Super Contributor
timestamp: January 13, 2020, 08:30:23 pm
content: And its back to being slow.

author: JLCPCB Official
author_rank: Regular Contributor
timestamp: June 17, 2020, 07:56:02 am
content: Quote from: calexanian on January 13, 2020, 08:30:23 pmdoes this situation occurs often?
HERF - Page 1
Forum section: electronics / general

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: June 15, 2020, 06:26:13 pm
content: I've been leafing through some 1960s books (because the 1960s were awesome) and I saw a quick mention of something called "high-energy-rate forming".It is about using explosives to form metal parts. Oh how I love this general whackiness. I found a video.It has a quite loud audio artifact at the start but oddly the rest of the audio is quite low and muffled.I love the fact that it looks like it's just two guys in lab coats walking around a field stuffing explosives into washbasins and blowing stuff up.
Rare Annular Solar Eclipse, Sunday - Page 1
Forum section: electronics / general

author: KL27x
author_rank: Super Contributor
timestamp: June 19, 2020, 08:56:08 pm
content: https://www.cnn.com/2020/06/17/world/solar-eclipse-june-2020-trnd-scn/index.htmlJust heard, myself, IRL. Hope this isn't old news to you guys. A partial eclipse should be visible from Northern Australia. The the real-deal is only a narrow strip that'll cross parts of Africa, Middle East, and Asia. Or if you are on a boat, you could have a great view from the Pacific Ocean.

author: DrG
author_rank: Super Contributor
timestamp: June 19, 2020, 10:41:50 pm
content: I'm all set and still have my eclipse glasses.As worn by Charlie SheenNow, if I can just get out into the Pacific Ocean by Sunday.[Charlie Sheen photograph courtesy ofhttps://www.eclipseglasses.com/pages/image-gallery]
Optics lens design sw recommendation - Page 1
Forum section: electronics / general

author: pisoiu
author_rank: Regular Contributor
timestamp: June 16, 2020, 06:35:20 pm
content: Hi,Optics is not my strong point. I understand basic principles but that's about it. However, I need to design a lens system and I have nobody I could ask to do that for me.Basically I have a laser diode and I need to pull out from it a parallel beam of a certain dimension. For that, I need to use a convex lens or an assembly of concave and convex lens, because I have some size restraints.Can anyone recommend me a free application for basic optics design in which I can enter some lens parameters and see how the light propagates? I do not need complex things, no coatings, I work with single wavelenght, etc. The goal is to get parameters of the lens I need, so I can send them to chinese manufacturers to make them.Thanks.

author: pisoiu
author_rank: Regular Contributor
timestamp: June 16, 2020, 09:20:00 pm
content: Found:https://arachnoid.com/OpticalRayTracer/

author: jmelson
author_rank: Super Contributor
timestamp: June 16, 2020, 10:00:16 pm
content: Quote from: pisoiu on June 16, 2020, 06:35:20 pmGenerally, a sphere lens is used for this, almost touching the front of the laser module. You can get 2mm and 3mm sphere lenses.Jon
Anyone trading bitcoins? - Page 1
Forum section: electronics / general

author: Beamin
author_rank: Super Contributor
timestamp: August 14, 2017, 09:06:28 pm
content: I have a wallet on my phone and out of curiosity I checked it today. What was 10's of $ turned into a few hundred. I bought it last time 2013 when it was 1200 then mtgox exploded and didn't pay much attention to them. I have another account but sadly I can't find where my 2 factor ID is as the one of the copies I made was in my real wallet which was stolen. I still have the print copy some where that has 0.5 in it or about $2000 today. Teach me to loose things.

author: daybyter
author_rank: Frequent Contributor
timestamp: August 14, 2017, 09:33:03 pm
content: Kinda. I used to write code for tradebots many moons ago. Moved on to other currencies at the moment.

author: ebclr
author_rank: Super Contributor
timestamp: May 25, 2020, 01:43:12 pm
content: I would prefer to trade Holand Tulipes instead

author: KL27x
author_rank: Super Contributor
timestamp: May 25, 2020, 10:21:46 pm
content: QuoteI remember hearing about an NFL player who bought bitcoins early on. The value got to over 200 million US.His financial advisor "lost" the key. Everyone assumes he is on an island with 200 million dollars. But maybe he actually lost the key?If you want to store value in something that doesn't undergo inflation, what's wrong with gold bars? I don't get bitcoin the "mining" part. Let's use megawatts of electricity and racks of servers to make more of this imaginary crap?The question: no. If I did short term trading, I am positive I could lose everything I own in a matter of weeks. It just takes a few days of insanity to do that, and I go through those days.

author: RoGeorge
author_rank: Super Contributor
timestamp: May 25, 2020, 10:29:06 pm
content: Give me $100 million and in one year I'll break any encryption, no keys asked.

author: amyk
author_rank: Super Contributor
timestamp: June 16, 2020, 02:51:50 am
content: You're not alone... there's probably hundreds if not thousands of others who, when it first started, were very curious what it was about, mined a bit, and then either thought it would amount to nothing and deleted them, or forgot about and eventually lost them.

author: james_s
author_rank: Super Contributor
timestamp: June 16, 2020, 04:34:10 am
content: It's just gambling. For everything like bitcoin that takes off and gets valuable there are a hundred other creations that flop. I never thought much about crypto currencies because it's completely irrational, but people are irrational in general.
Physics forum - Page 1
Forum section: electronics / general

author: RoGeorge
author_rank: Super Contributor
timestamp: June 13, 2020, 07:42:11 am
content: Is there any forum for physics like EEVblog is for electrical engineering, where both amateurs and professionals that shares the same interest for science in general, and physics in special, like to hang together?So far Google gave me only homework Q&A style forums, or completely off free energy style forums.Any recommendation for something in between, please? Maybe the question is trivial for others, but I am not into academia, so where do physicists like to hang and chat about ideas or experiments? Are there any such places (other than Uni labs or conferences)?

author: ChristofferB
author_rank: Frequent Contributor
timestamp: June 13, 2020, 09:46:38 am
content: I've pondered this too. A lot of scientific forums seem to be based mainly on homework, and will discourage free discussion. I feel like this is pretty detrimental to the respective sciences. Physicsforum is a bit better but not that great.For the physics I'm interested in, that is; high voltage, high vacuum, and radiation detection/spectroscopy I've found fusor.net to be pretty good,even though I'm not actually trying to build a fusor.EEVblog forums really is the crown of technical discourse, I feel. Both in terms of tone, expertise and user base.

author: pardo-bsso
author_rank: Frequent Contributor
timestamp: June 13, 2020, 02:26:05 pm
content: I like this one a lot, but it's in Spanish:http://www.cientificosaficionados.com/foros/index.php

author: unitedatoms
author_rank: Frequent Contributor
timestamp: June 13, 2020, 04:47:18 pm
content: Eevblog could only benefit from physics topics. After all Art of Electronics book was made for scientists working in physics. However just let's remember that lord Kelvin declared the Physics to be a complete and done science, so the academy could be disbanded, since all electrical laws were discovered and there is nothing left to work on.

author: jmelson
author_rank: Super Contributor
timestamp: June 13, 2020, 07:05:08 pm
content: Quote from: RoGeorge on June 13, 2020, 07:42:11 amWell, of course, just a google search away, it is :https://www.physicsforums.com/While there are homework problems there, they also have forums on the Japanese reactor accident and probably anything else you'd be interested in. Use the search box at upper right.Jon

author: TimFox
author_rank: Super Contributor
timestamp: June 15, 2020, 06:30:53 pm
content: Quote from: unitedatoms on June 13, 2020, 04:47:18 pmLord Kelvin made some inappropriate comments about vectors and heavier-than-air aircraft, but he never said that physics was complete and done.See "Misattributed" inhttps://en.wikiquote.org/wiki/William_Thomson
Small character LCD module with pinouts and dimensions available - Page 1
Forum section: electronics / general

author: Axk
author_rank: Regular Contributor
timestamp: June 14, 2020, 12:31:56 am
content: I'm looking for a small character LCD module (only need 5 digits) (with the controller) with pinout, pin distance and dimensions available that I can buy from Aliexpress or Ebay.And also with info on the interface available.Something like this one but with the pinout and the distance between the rows of the pins available so that I can design a board around it while it's being delivered:https://www.aliexpress.com/item/4000408781421.html?spm=a2g0o.productlist.0.0.59de389cOmII5y&algo_pvid=4d9f2c99-6c3a-47e6-a8a1-cb0cf66c6009&algo_expid=4d9f2c99-6c3a-47e6-a8a1-cb0cf66c6009-2&btsid=0b0a0ac215920915164453842e925d&ws_ab_test=searchweb0_0,searchweb201602_,searchweb201603_

author: rhodges
author_rank: Frequent Contributor
timestamp: June 14, 2020, 03:26:13 pm
content: Maybe something like this? It has 6 digits and uses the HT1621 driver:https://www.ebay.com/itm/332711080391I took a quick look at the HT1621 datasheet, and it looks like you can use SPI.The ebay seller also states you can use SPI.Maybe you can ask the ebay seller to take a picture of the pins and silkscreen side?And give the measurements you need?

author: Buriedcode
author_rank: Super Contributor
timestamp: June 14, 2020, 07:10:04 pm
content: Also, character LCD's are available for 8x1.Random example:https://www.ebay.co.uk/itm/8x1-LCD-Display-Character-Module-w-Tutorial-HD44780-FFC-Connector-Black-on-White-/301020329281

author: ebclr
author_rank: Super Contributor
timestamp: June 15, 2020, 06:15:49 am
content: HT1621 is extremely easy to drive
PCB for pick and place - Page 1
Forum section: electronics / general

author: generic_username
author_rank: Regular Contributor
timestamp: June 16, 2020, 06:46:21 am
content: Hello everyone,I have a specific need for a PCB part to compensate height differences.I attached a picture to illustrate my problem (100% Paint skillz)As can seen in the attached picture I must compensate around 2-3mm. The foil(red) will be attached to the PCB via a conductive adhesive which has low bonding strengh so the bending is sometimes putting to much strain on the connection and will break, to prevent the breaking the PCB will be potted but the time between applying the adhesive and the potting is where there can be problems.As I couldn't really find a standard component that I can use for a way to compensate the difference in height I'd like to make a simple PCB to be solderend on top to be used as a spacer.The PCB must not really be a complete match with the height difference but shall lessen the burden until potting.producing a PCB to do this is not really the issue but I have yet to find a company that would put this PCB's into a reel for pick and place process.If anyone knows a company that does this or has done that, would be appreciated, I had no luck so far in my search so far.PS if anyone knows a better way to accomplish the same it would really be kind to share this knowledgecheers.
Flat panel phased array antennas are great? - Page 1
Forum section: electronics / general

author: ocset
author_rank: Super Contributor
timestamp: June 11, 2020, 12:05:24 pm
content: Hi,I see Phasor Solutions has just gone bust..https://advanced-television.com/2020/05/11/uks-phasor-goes-bust/I just don’t understand it..i would have bought shares…flat panel, phased array antennas are a fantastic idea. Howcome it went bust?

author: PlainName
author_rank: Super Contributor
timestamp: June 12, 2020, 08:45:03 am
content: thunderfoot probably busted them about something - no way a flat panel can focus, obvs.

author: coppice
author_rank: Super Contributor
timestamp: June 12, 2020, 10:04:45 am
content: "Phasor is Virginia and London-based and is a specialist supplier of flat electronically steered antennas for use on aircraft, maritime, trains and military vehicles."When you are in markets like that, you tend to be one contract away from disaster. The transport market isn't looking great at the moment. I'm not clear how military systems are doing, but most governments need to tighten their belts right now.

author: ocset
author_rank: Super Contributor
timestamp: June 12, 2020, 10:49:16 am
content: QuoteThanks i agree.But the UK Gov is currently dishing out 19 billion £'s a month to people who are not at work due to covid.I am seriously concerned that the UK cant print money like this and survive.

author: Lord of nothing
author_rank: Super Contributor
timestamp: June 13, 2020, 08:49:15 am
content: QuoteWhy? New Trains get order frequently because the old went out of Service.And the NATO still want start a illegal War with many country mostly Iran.

author: coppice
author_rank: Super Contributor
timestamp: June 13, 2020, 09:23:29 am
content: Quote from: Lord of nothing on June 13, 2020, 08:49:15 amBoeing and Airbus's prospects for the next few years are not looking bright...Quote from: Lord of nothing on June 13, 2020, 08:49:15 am... and the recession we are entering will depress tax revenues for years, which does actually depress new defence projects, as they never want to defund the ones in progress.

author: Lord of nothing
author_rank: Super Contributor
timestamp: June 13, 2020, 11:10:48 am
content: If the US would put 10% of the Military Budget put into funding Public Schools maybe the would be not on that many People with low income.
Trying to figure out this SMD part - Page 1
Forum section: electronics / general

author: Yamin
author_rank: Frequent Contributor
timestamp: June 10, 2020, 11:14:53 am
content: Hello everyone I'm trying to figure out this SMD part. The markings on it are 'OM' or '0M' at the top half and 'XT' on the lower half.Also what type of package is this?I have tried to search for it online with no luck.Also any tip on identifying these kind of hard smd parts would be greatly appreciated:)Thanks in advance.

author: Krotow
author_rank: Regular Contributor
timestamp: June 10, 2020, 12:00:04 pm
content: Suspiciously similar to LDO. But can't say without knowing how it is connected in PCB.Another proof that the batches of components ordered in bulk by other manufacturers may have cryptic labels or no labels at all. Had Western Digital My Cloud Home NAS to repair where DC step-down ICs had something like 0B=0L on them. And exactly same IC's on two same model boards from different batches had different labels. Seems they use IC batch number instead of recognizable label.

author: Psi
author_rank: Super Contributor
timestamp: June 10, 2020, 12:23:46 pm
content: C7 and C8 also suggest a voltage regulator.

author: JackJones
author_rank: Regular Contributor
timestamp: June 10, 2020, 12:48:43 pm
content: It definitely looks like a regulator. It's almost impossible to find the exact part number if you don't find anything with the markings.The package is SOT-223, they are usually voltage regulators or transistors.

author: amyk
author_rank: Super Contributor
timestamp: June 11, 2020, 02:33:12 am
content: According tofamous Russian site, that would be a MC78FC50HT1G.This sellerhas a picture (see attached) which confirms the 0M marking.Quote from: Krotow on June 10, 2020, 12:00:04 pmThat's a Richtek part, more preciselyRT7298AHGQW. Theimagethere confirms it. Only part of it is the ID code, the rest is the batch/lot code.

author: Yamin
author_rank: Frequent Contributor
timestamp: June 12, 2020, 07:30:58 pm
content: Thanks everyone for the help, yes its turns out to a voltage regulator! Was able to confirm this on a working board - Pin1 = Ground, Pin2= Input(12V), Pin3 = Output(5V).Nice tip with the two capacitor close.and @amyk - Wow thanks so much for the new resourceful site. I didn't know that it existed definitely bookmarking it!
Advice for tape/sealant for Saab rear window trim - Page 1
Forum section: electronics / general

author: eti
author_rank: Super Contributor
timestamp: June 10, 2020, 10:52:09 pm
content: Hello!My friends, I need some help - can you recommend a solution to coat the rear-top seal of a Saab rear window? The seal integrity is fine, but there is a black painted strip of metal above it, where the black paint has worn off, over the years. I had suggested self-amalgamating tape (as used for weatherproof seals for sat dishes - we used to use that a lot) but I wasn't sure if this would be correct advice.If you know, would you reply? Many thanks me old Chinas.

author: helius
author_rank: Super Contributor
timestamp: June 11, 2020, 01:05:31 am
content: Self-amalgamating tape is for wrapping leaky hoses with overlapping layers.Are you looking for an adhesive, or a paint?

author: eti
author_rank: Super Contributor
timestamp: June 11, 2020, 01:27:15 am
content: I am looking for a paint. Thanks!

author: deadlylover
author_rank: Frequent Contributor
timestamp: June 11, 2020, 01:38:34 am
content: Hmmm how about plasti dip? Should be able to find a can easily at your local auto parts store.Easily removable and I think it will match the look of the original paint (sort of dull and slightly matte, it isn't shiny).

author: Lord of nothing
author_rank: Super Contributor
timestamp: June 12, 2020, 11:23:40 am
content: Does we talk about such Saab Product?
electromagnetic hammer - Page 1
Forum section: electronics / general

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: June 16, 2020, 02:16:31 am
content: Here's some more 1960s stuff I never heard of before.This involves electronics and rockets. Everyone loves rockets, come on!

author: amyk
author_rank: Super Contributor
timestamp: June 16, 2020, 03:00:03 am
content: A far more interesting video than the title would suggest; I thought it was just an electric version ofthe common air tool.Mikeselectricstuff has built something very similar...http://www.electricstuff.co.uk/surge.html

author: ealex
author_rank: Frequent Contributor
timestamp: June 16, 2020, 01:04:41 pm
content: the first recommended clip:niiiiice
are jfet drain and source interchangeable? - Page 1
Forum section: electronics / general

author: vixo
author_rank: Regular Contributor
timestamp: June 10, 2020, 08:56:02 am
content: I use 2n3819s sometimes but there are two pinouts - fairchild is different to ON semi, with the drain and the source being changed round. Does this matter? I always thought No, but I was very confused in the past when i bought a few which didnt work. I put this down to the fact they were the wrong pin out, by I have since learnt that there are some fakes of these floating around...should it make a difference?

author: Yansi
author_rank: Super Contributor
timestamp: June 10, 2020, 09:03:03 am
content: Shouldnt make a difference as far as I know.

author: madires
author_rank: Super Contributor
timestamp: June 10, 2020, 09:50:23 am
content: Not really, it's fine in many cases. But there are also some JFETs where it matters. You can find the real source by measuring the gate-source and gate-drain capacitance. The gate-source capacitance will be much lower.

author: Kleinstein
author_rank: Super Contributor
timestamp: June 10, 2020, 10:07:55 am
content: With many JFETs there is no real difference between drain and source. So a circuit should still work if "reversed", as the variations between units are larger than from reversion the chip.Especially JFETs for high frequency use can have intentional asymmetry and better performance when used the right way around. AFAIK the gate to drain capacitance should be the smaller one in most applications - so it could depends on the circuit which way is better.The 2N3819 seems to be asymmetric with a low Crss (gate - drain).

author: SiliconWizard
author_rank: Super Contributor
timestamp: June 10, 2020, 02:58:25 pm
content: As said above, not all discrete JFETs are symmetrical (from experience it's even slightly uncommon, but YMMV.) In any case, check the datasheet, although it's not always easy to derive that information from some datasheets.
Power supply power factor - Page 1
Forum section: electronics / general

author: raptor1956
author_rank: Frequent Contributor
timestamp: June 08, 2020, 11:08:51 pm
content: I just picked up the new DJI Mavic Air 2 drone and since I plan on charging my batteries in my car using an inverter I wanted to know what the power draw of it is. So, I plugged the little power brick for the drone charger into a Kill-A-Watt and saw that the charge power was around 36W, a bit less than I guessed, but the VA was over 70VA making the power factor pretty bad at not much more than 0.5. That seems really low, what might be the reason?Brian

author: NiHaoMike
author_rank: Super Contributor
timestamp: June 09, 2020, 12:23:51 am
content: Not much point having PFC for small loads. See what voltage the power adapter is and you might be able to find something like a laptop adapter for a more elegant solution than an inverter, or even power the charger from a larger battery out in the field.

author: themadhippy
author_rank: Super Contributor
timestamp: June 09, 2020, 12:40:53 am
content: Quotemore than likely there using a capacitor dropper instead of a more expensive transformer

author: srb1954
author_rank: Super Contributor
timestamp: June 09, 2020, 12:44:53 am
content: A power factor of 0.5 is fairly typical for a simple power supply without power factor correction.

author: raptor1956
author_rank: Frequent Contributor
timestamp: June 09, 2020, 04:57:39 am
content: I didn't expect the PF to be over 0.8 but I wouldn't have expected it to be under 0.6 either. Now, add in the losses with the inverter and to get, say, 40W out I'll need to source right at 100W or 8A -- within the range of the cars outlet.Brian

author: Kleinstein
author_rank: Super Contributor
timestamp: June 09, 2020, 06:00:21 am
content: The cheap meters may have some error in reading the power factor, if there are sharp spikes in the current (like with a rectifier and capacitor). Many cheap inverters don't produce a nice sine. So the power factor may be different with that waveform. This can range from works well to not working at all. Many such charger say one should not run them on inverters because there is a chance to cause trouble.It depends on the inverter how well it can handle a load with low power factor. Delivering 80 VA does not mean the inverter has to draw > 80 W from the source.If the charger uses an external power supply (e.g. SMPS to some 5-24 V), the more logical way would be a direct way DC to DC with not 115 V 60 Hz in between. There may be suitable ones for laptops or similar.