hybridfree/eevblog-posts huggingface dataset:
Are these light fixtures conductive? - Page 1
Forum section: electronics / beginners

author: fubar.gr
author_rank: Unknown
timestamp: December 12, 2015, 05:08:33 pm
content: I came across this eshophttp://www.jamjar.gr/store/edislampsThey sell decorative lights. The lamps they are using look like mains powered and the fixture is conductive and part of the live circuit, or am I mistaken?If so, this is electrocution waiting to happen. I was going to send them a message, warning them about the dangers, but I'd like a second opinion first. I wouldn't want to alarm them for no reason.

author: Ian.M
author_rank: Super Contributor
timestamp: December 12, 2015, 05:20:03 pm
content: Its almost certainly got a ceramic or phenolic insert between the body and the outer ES terminal. However they appear to have two wire mains leads and exposed metal parts, and I would want to see their full CE declaration of conformity (under DIRECTIVE 2014/35/EU), with its technical report to satisfy myself that the socket had reinforced insulation and was fit for purpose without earthing.

author: dom0
author_rank: Super Contributor
timestamp: December 12, 2015, 11:09:15 pm
content: Honestly I don't trust any lamp manufacturer anymore. They all write appliance class II / Schutzklasse II and CE on theirshit, but often insulation and cabling is of piss poor quality, independent of (supposed) country of origin and brand name. It has a mains cord, it gets a new one and the case is PE'd. It is for permanent installing, the case is PE'd. End of discussion.e:Re. the actual topic here, these look like the vintage brass E27 sockets still sometimes found in cellars around here. The outer brass shell isn't connected to anything or PE, there is an inner threading insulated by a bakelite or ceramic insert. I don't think they're "finger-safe" though. So maybe nothing to let little kids play with. It could also be the case that these lamps are actually low voltage lamps and the lamp base contains a transformer.
Are these neons?  - Page 1
Forum section: electronics / beginners

author: dentaku
author_rank: Frequent Contributor
timestamp: January 01, 2017, 01:25:25 am
content: I got this board from an old fax/copy machine. It has what looks like neons being used as some sort of fuse or something connected to an RJ45?Is that what they are?

author: mariush
author_rank: Super Contributor
timestamp: January 01, 2017, 01:33:24 am
content: I think they're gas discharge tubes, to protect against lightning strikes and stuff like that. A on the silkscreen could be short for arrestor, as in "surge Arrestor"

author: T3sl4co1l
author_rank: Super Contributor
timestamp: January 01, 2017, 02:08:28 am
content: Yes, sort of. They probably glow bluish, though, and ignite at a fairly high voltage (200V+?).Only one reason you'd find gas tubes near a phone connector: surge suppression.If a high voltage surge appears on the phone line (usually induced from nearby lightning strike), the tubes spark over and shunt the surge to ground (there should be a ground connection on the machine to carry this current).Tubes for this purpose are called Gas Discharge Tubes (GDTs). They are used where high power handling and fast response time are required, and where a low power or otherwise current-limited source is present (the worst the phone line can do is 10s of mA and something like 80V, not a big deal). They are unsuitable for unlimited sources and DC (because the arc will keep on burning until the device explodes).Other protection devices are thyristor (similar behavior and application; slower; often used on phone lines as well), MOV (huge energy handling, sloppy voltage limiting; typically used for mains and automotive), TVS (fast, reasonable voltage limiting, typically used for surge and ESD protection on LV supplies and signals) and clamp diodes (ESD protection, when an LV supply is present).Tim

author: dentaku
author_rank: Frequent Contributor
timestamp: January 01, 2017, 02:11:42 am
content: OKI thought I remembered Dave explaining this in an old video.
Are these open-circuit time constant method limits? - Page 1
Forum section: electronics / beginners

author: bonzer
author_rank: Regular Contributor
timestamp: January 04, 2019, 10:07:04 pm
content: Hello everyone! Please help me to understand some doubts about this method. ( Open-circuit time constant methodhttps://en.wikipedia.org/wiki/Open-circuit_time_constant_method).First of all it looks like it doesn't always work. Actually this wikipedia page isn't all of it but unfortunately I don't have an english explanation for you so I hope you already know it. But even there you can notice the limit - this method works for pole polynomials of typeP(s)=ansn+...+a0s+1or P(s)=sn+an-1sn-1+...+a0but it doesn't work in general so this surprises me. I mean I should somehow already know if there's a chance I have a pole in 0 or a lower number of poles than capacitors. This surprises me because I can't generally know first how it's gonna be while solving.What do you think?
Are these PSU spikes enough to cause trouble? - Page 1
Forum section: electronics / beginners

author: Chris Wilson
author_rank: Super Contributor
timestamp: June 09, 2015, 10:10:12 pm
content: I am battling with a highly complex HP spectrum analyser that shows noise spikes and jitter from time to time on it display. Thanks to the generous help of others I am slowly trying to track the cause down. I have measured the power supply lines after the regulator and on the -15V rail I see the spikes shown athttp://www.gatesgarth.com/SA/scope-shots.zipThe last two photos are of the scope looking at the +15V test pin. Whenever i see noise on the SA screen I also see it on the -15V test pin. I never see spikes on + or -5V, or +20V or +15V supplies. The PSU in the SA is a linear, the machine an HP8568B.My test methodology is probably poor, with a fairly long ground lead, but the fact only -15V shows these spikes is surely significant? The probe was set to X1. The scope an old Tek 7854Thanks for looking.

author: slateraptor
author_rank: Frequent Contributor
timestamp: June 10, 2015, 06:06:42 am
content: It sounds and looks and smells like noise coupling, but I suspect only you can tell us if |?V/V| = 0.27% is trouble or not.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: June 10, 2015, 09:24:15 am
content: Can you focus the scope trace?Also zoom on the spikes, they look ~sort of~ consistent, not that there should be any reason for such a thing to be produced randomly from a linear supply regardless. A DSO (or single sweep + long exposure in dimly lit room) would be helpful here.Possible culprits: electrical breakdown (capacitor? diode/transistor avalanche?), coupling (AC line noise? nearby transients?), frayed wires (intermittent shorting or breakdown), crummy resistors..?!Aside from aging capacitors (electrolytics are always prime suspect), almost anything else is a stretch.Tim
Are these v-scores big enough? - Page 1
Forum section: electronics / beginners

author: Ram80
author_rank: Contributor
timestamp: August 20, 2024, 05:01:16 am
content: I did these in kikit, the boards are 4.5cm x 4.5cm.I selected v-cuts in kikit but they looks very small, will these be ok?

author: Andree Henkel
author_rank: Regular Contributor
timestamp: August 20, 2024, 08:09:54 am
content: according to your picture it looks like the single pcbs on the use will be separated by milling, not by v-scoring.if your actual question is about milling diameter 2.4mm is a good size for this purpose.or look at the tech info of the pcb manufacturer you want to order the raw pcb at.They hav spec for minimum milling diameter associated with a pcb-class.They also specify miniimum milling diameter usable without additional cost

author: Ram80
author_rank: Contributor
timestamp: August 20, 2024, 08:53:23 am
content: Not sure I understood thatI mean the small mouse bites holding the PCBs together are these big enough?They were actually selected as v-cuts in kikit but they don't look like v-cuts to me.

author: Andree Henkel
author_rank: Regular Contributor
timestamp: August 20, 2024, 09:14:43 am
content: mouse bites are not v-score either, they are just small through holes with no plating (no copper, not through hole plated)look up what v-Scoring actually is.good hole diameter for the "mouse bites" is 0.2mm.place at least 2, better 3 mouse bite holes,

author: Andree Henkel
author_rank: Regular Contributor
timestamp: August 20, 2024, 09:18:14 am
content: look at the two vid by Davethey explain this stuff:

author: selcuk
author_rank: Frequent Contributor
timestamp: August 20, 2024, 09:22:00 am
content: There are no V-cuts in the design and the mouse bites are missing on the tabs as well.I'm using these two files as templates for panelizing. You can try them.https://github.com/uysan/iot-esp-eth/tree/main/pcb/iot-esp-eth-com/panelAdditionally you may export your KiKit configuration and paste here for suggestions.
Are these transistors ok? - Page 1
Forum section: electronics / beginners

author: aaronhance
author_rank: Regular Contributor
timestamp: December 14, 2015, 02:52:13 pm
content: I'm thinking of usingthesetransistors to switch a 12v 120w heater and a 12v 40w heater, would they be ok to use for this? Also willtheseheat sinks be good for them? Thanks again, in advance!

author: c4757p
author_rank: Super Contributor
timestamp: December 14, 2015, 02:58:26 pm
content: Eh... you can do better for the 120W heater, you're wasting rather a lot in the FET. How'sthis? Should barely need a heat sink.Of course, it might not matter if the FET will be dissipating heat into the same space as the heater. It'll just contribute a bit of heat itself. All depends on your application.

author: Delta
author_rank: Super Contributor
timestamp: December 14, 2015, 03:00:29 pm
content: I'd look for a FET with a lower on resistance - RDS(on).120W at 12v is 10A, so 10A through that device with an on resistance of 110 milliohms means it will be dissipating 11 Watts - not too good.PS. Remember that you'll need to drive the gate with at least 10v, not the 5 or 3.3v from an MCU....

author: aaronhance
author_rank: Regular Contributor
timestamp: December 14, 2015, 03:03:52 pm
content: Ok, thanks for the help! I guess I drive them using a second transistor with a lower control voltage, since I have 12v on the board already!

author: madires
author_rank: Super Contributor
timestamp: December 14, 2015, 03:30:35 pm
content: Logic level (5V): IRL140412V: IRF2805

author: aaronhance
author_rank: Regular Contributor
timestamp: December 14, 2015, 03:45:24 pm
content: Quote from: madires on December 14, 2015, 03:30:35 pmHi, thanks, I was looking at a similar part.

author: Marco
author_rank: Super Contributor
timestamp: December 14, 2015, 04:34:28 pm
content: Does it have to be through hole? If not you're spoiled for choice. IRL1404 is a nice part but you can find much cheaper solutions.If it has to be through hole the choice of cheap parts in low volume is a bit limited, but there's stuff like AOI514.
Are those switching transformers - Page 1
Forum section: electronics / beginners

author: fixit7
author_rank: Regular Contributor
timestamp: June 04, 2019, 11:10:31 pm
content: Are those both switching transformers?https://www.dropbox.com/s/z5dqd7lacwrzq9w/SwitchingTransformer.png?dl=0Thanks.

author: Stray Electron
author_rank: Super Contributor
timestamp: June 04, 2019, 11:25:12 pm
content: You might bet more replies if you used a picture host that doesn't require that wejoinand log into.

author: ArthurDent
author_rank: Super Contributor
timestamp: June 05, 2019, 12:39:22 am
content: Front looks like switching transformer, rear one is A.C. line common mode choke.

author: fixit7
author_rank: Regular Contributor
timestamp: June 05, 2019, 01:52:28 am
content: Thanks for the help.Andy

author: strawberry
author_rank: Super Contributor
timestamp: June 05, 2019, 06:49:32 am
content: Quote from: ArthurDent on June 05, 2019, 12:39:22 amIt is flyback topology swithcing mode power supply. It is not exactly a transformer but gapped inductor with secundary winding. Its output voltage is not determined by turns ratio

author: fixit7
author_rank: Regular Contributor
timestamp: June 05, 2019, 12:59:45 pm
content: Thanks.QuoteIs the shielding similar to the copper/zinc mesh that I have seen?I am reading Understanding Basic Electronics by Larry Wolfgang and one chapter mentioned EMI.

author: strawberry
author_rank: Super Contributor
timestamp: June 05, 2019, 03:00:25 pm
content: Quote from: fixit7 on June 05, 2019, 12:59:45 pmif wire is surrounded by copper mesh, it becomes shielded wire or cable.transformers are shielded with copper tape or steel cage/box to reflect and absorb radioation, most of ityou can shield sensitive components from noise or the noise source or both
ARM - Page 1
Forum section: electronics / beginners

author: Lunat1c
author_rank: Contributor
timestamp: March 04, 2011, 07:46:46 pm
content: Hi, could anyone please guide me to the books and/or software I need to properly learn assembly language? My focus is going to be ARM7 for now as that's what I'm learning on.

author: desowin
author_rank: Contributor
timestamp: March 05, 2011, 09:03:01 pm
content: Andrew N. Sloss, Dominic Symes, Chris Wright - ARM System Developer's Guide Designing and Optimizing System SoftwareYou can't go wrong with that book, the only downside is that it is a bit old, hence no word about Cortex in it, but I think that's not problem for you, as you need ARM7 which is covered fairly well

author: tyblu
author_rank: Frequent Contributor
timestamp: March 05, 2011, 09:27:42 pm
content: Family datasheets are often very good.

author: Zad
author_rank: Super Contributor
timestamp: March 06, 2011, 04:18:57 pm
content: ARM themselves have a huge number of free PDF data sheets and information books. Unfortunately not long ago they changed their sites so now all my links don't work...

author: Psi
author_rank: Super Contributor
timestamp: March 07, 2011, 12:25:41 am
content: Learning asm can teach you a lot, just dont expect the skill to get you a job coding ARM chips in asm all day.Asm is really only used in tiny micros or for very small sections of inline asm as part of your main C code.ARM chips are so fast and powerful that almost everyone programs them in C with maybe a few 10line asm functions if needed.Becoming an ARM asm expert isnt going to be a very good use of your time if you want to learn and work as an ARM programmer.If on the other hand you just want to learn it for fun or so you can understand exactly how a cpu works at a low level then leaning asm is a great idea.

author: tyblu
author_rank: Frequent Contributor
timestamp: March 07, 2011, 05:40:29 am
content: Useful to write some drivers in ASM on ARMs, especially if bit-banging fast protocols.

author: VIPR
author_rank: Contributor
timestamp: March 07, 2011, 01:52:46 pm
content: Here's a good but fairly expensive book (price of a good college textbook) that will be guaranteed to teach you everything there is to know about assembly language and the ARM processor:http://www.crcpress.com/product/isbn/9781439806104.However, unless you are having to learn the assembly for a uni class you might as well just skim some quick PDF's on the subject and then go straight to using C or C++ for all your micro programming needs.

author: TheDirty
author_rank: Frequent Contributor
timestamp: March 07, 2011, 03:08:15 pm
content: It's a little tough as well, because any book on assembler, like the linked one is going to be generic ARM assembly. Since they only make the core and all the peripherals are specific to the manufacturers you're not going to get anything specific to the uC you are working with. I mean it's not going to be like a PIC or AVR guide with examples on how to setup I/O, UART, or anything like that.ARM7 is not recommended for new designs by ARM, so don't get too attached to it.
ARM2148 USB Development Board - Page 1
Forum section: electronics / beginners

author: Lunat1c
author_rank: Contributor
timestamp: April 03, 2011, 05:35:07 pm
content: Hi,I have recently purchased the ARM2148 Development Board and I'm trying to find a program with which I can load programs to the flash memory of the board via USB. The board I'm talking about is this one:http://www.futurlec.com/ARM2148_USB_Development_Board.shtmlI know that there are programs such as Flash Magic however they do not allow for program loading via USB but only via RS232 which is a port that I don't have on my pc/laptop.So can anyone name some programs I could use to load programs via USB please?

author: Unknown
author_rank: Unknown
timestamp: April 03, 2011, 06:01:02 pm
content: Some USB-to-serial converters are said to work well with Flash Magic. Other option would be a JTAG programmer (don't think the LPC21xx supports SWD) with a USB interface.

author: jahonen
author_rank: Super Contributor
timestamp: April 03, 2011, 06:24:43 pm
content: My experience has been that the Flash Magic works just fine with USB RS-232 adapter, no problems at all. This is because ARM bootloader uses standard RS-232 protocol, not any timing critical bit-banging one.Regards,Janne

author: neoone
author_rank: Regular Contributor
timestamp: April 03, 2011, 10:18:41 pm
content: I have quite experience with both LPC2148 and Flash Magic including USB-serial adapter. There were some occasions when I had some problems with FM but not sure if it was on 2148 (for sure on LPC1768) but absolutely no problems with lpc21isp - this is a console program that also uses LPC bootloader and is free (Flash Magic is free for non commercial use only). I've used a regular RS232 port, FT232 based converters and also PL2303 base converters. It usually works better (faster) on FT323. There are 2 additional pins you need to use besides RX and TC - DTR for uC reset and RTS for ISP-P0.14. It is also pretty easy to invoke bootloader manually without connecting those pins to USB-serial converter.If you'd really like to use USB directly for programming it is possible to create secondary bootloader via USB but USB to serial converter is way easier.

author: Lunat1c
author_rank: Contributor
timestamp: April 16, 2011, 10:03:18 pm
content: Guys, would a RS-232 Serial Port to ExpressCard Adapter work just fine in this case?
Arranging capacitors and shelf life - Page 1
Forum section: electronics / beginners

author: sairfan1
author_rank: Frequent Contributor
timestamp: August 21, 2020, 02:23:48 pm
content: Cleaning up my lab, I have lots of capacitors (most of them electrolytic, ceramic, tantalum in SMD/dip package) sitting around, bought from China, ebay/aliexpressI want to know how can i categorize them, like for resistors we arrange in 1 to 9 numbersWhile googling around show to arrange capacitors i came to know that there is also something regarding capacitors and that is shelf life, what should i consider regarding it.

author: wizard69
author_rank: Super Contributor
timestamp: August 21, 2020, 04:44:21 pm
content: Quote from: sairfan1 on August 21, 2020, 02:23:48 pmIt really depends upon how many of each type and voltage range you have. Generally you sort by micro-farad however if you have caps in quantity, in a wide array of voltage ranges, it helps to sort by voltage also.As for electrolytics I don't see keeping of lot of them "in stock" as a good idea. However storing by capacitance is the normal appproach.

author: rsjsouza
author_rank: Super Contributor
timestamp: August 21, 2020, 06:29:55 pm
content: Just an added detail regarding storage of electrolytic capacitors: depending on the quality of the capacitors and the temperature they are stored, their shelf life should be very long. In other words, I wouldn't throw anything away just for the fear of having something in bad shape.You could even plan to get one of the cheap component testers or even a more featured LCR meter to test these parts before you assemble your kits and projects.The Tantalum capacitors are much less prone to shelf life issues, and the ceramic are virtually unaffected.I have 10, 20 and even 30 year-old electrolytic capacitors in excellent shape.

author: TimFox
author_rank: Super Contributor
timestamp: August 21, 2020, 07:44:20 pm
content: For surface-mount parts, manufacturers often state a shelf life, based on how long the parts can go after the package is opened before soldering them to the PCB becomes unreliable due to reactions between the metal and air.

author: bob91343
author_rank: Super Contributor
timestamp: August 21, 2020, 07:44:47 pm
content: I sort electrolytic capacitors by style such as can, very old tubular, and size. Beyond that I sort by voltage. I have a box of 16V units, a box of 'over 100V' and so on. The mica and ceramic are in a separate place, and the paper/plastic elsewhere, with low capacitance ceramic and mica elsewhere. Variables in a big box..I just ponder what my thoughts would be when I need a part. What would I want? I don't want to violate voltage ratings and am willing to parallel capacitors to achieve a value so sorting by value is not that big a deal.And this is important, particularly if you have a large stock. I periodically look them over and even measure a few just to familiarize myself with what I have so I can look methodically for something I need. In the process I compare readings from different bridges to verify my instruments.
Array of high side switches - Page 1
Forum section: electronics / beginners

author: tridentsx
author_rank: Regular Contributor
timestamp: November 15, 2015, 12:09:27 pm
content: I have been looking for some chip implementing an array of high side switches? Is there something like that ?I know I could build it using pnp npn pair but I would like to reduce component count and the size of pcb.Its strange I have problem even finding npn transistor array.

author: German_EE
author_rank: Super Contributor
timestamp: November 15, 2015, 12:56:00 pm
content: This is a strange problem that I have also encountered. The ULN200x series have been around for a long time but every chip in the series pulls the load down to a nominal ground level. What we need is the same chip with the emitter connected to Vcc and the collector fed out to a pin.Is there an actual demand for such a chip, if so, why doesn't someone manufacture a 7 x high side switch?Edit: They do, and that Micrel part looks quite good.

author: Simon
author_rank: Unknown
timestamp: November 15, 2015, 04:16:00 pm
content: You want an outout driver chip, does it specifically have to be high side only ? there are plenty of dridge and half bridge drivers that will work if your ok with the output pulling to ground when off.

author: Yansi
author_rank: Super Contributor
timestamp: November 15, 2015, 04:27:08 pm
content: UDN2981 or its replacement. (2981 no longer manufactured, unfortunately I can't recall the name of the supplement)

author: Jeroen3
author_rank: Super Contributor
timestamp: November 15, 2015, 09:01:50 pm
content: Search for high side switches or power management ic's. There are plenty, Infineon has some high current automotive parts. (Or the same, a bit more current, industrial)They also have arrays of 4, with the power limitations that come with them.I just recently desinged in an mic2009 from micrel, to discover there are plenty usb level high side switches with current limit.

author: Simon
author_rank: Unknown
timestamp: November 15, 2015, 09:04:12 pm
content: I think most of IR's parts are moving to automotive only options as well now that infinion has bought them. We had to do a "substitution" the other day that amounted to reselecting the same part with a new part number because infinion are ditching the consumer ranges of Ir where an automotive one exists.

author: MarkL
author_rank: Unknown
timestamp: November 15, 2015, 10:36:06 pm
content: If you're driving from a microcontroller and can use SPI, you might want to take a look at the MC33880 or NCV7608. They are both octal output and configurable high or low side drive, with built-in fault protection, open load detection, PWM inputs, and inductive clamping. Very versatile and readily available.http://cache.freescale.com/files/analog/doc/data_sheet/MC33880.pdfhttp://www.onsemi.com/pub/Collateral/NCV7608-D.PDF

author: Andreas
author_rank: Super Contributor
timestamp: November 16, 2015, 10:23:32 pm
content: Quote from: Yansi on November 15, 2015, 04:27:08 pmTD 62783AP

author: Yansi
author_rank: Super Contributor
timestamp: November 17, 2015, 11:17:17 pm
content: Yes, exactly, thats it!Thanks for the code.
Arg, need a cheap source 120v/240v AC in to 9 or 12v AC out wall wart.  [FOUND] - Page 1
Forum section: electronics / beginners

author: BrianHG
author_rank: Super Contributor
timestamp: February 26, 2018, 09:09:21 pm
content: Arrrrrrggggg, where to buy, new, cheap and still standard stock. I need a cheap source 120v AC in to anywhere between 9v to 12vACout wall wart, 250ma through 1 amp would be ok. Approvals preferred.Everything is useless crummy DC out... I can find 2$ DC units with free shipping, but, when it comes to AC, I need to pay over 20$ + shipping.

author: IanB
author_rank: Super Contributor
timestamp: February 26, 2018, 09:22:02 pm
content: That's basically a 12 V step down transformer. If you try to buy the bare transformer it will usually cost about $10. So put it in a case and add assembly, testing and approvals and I can see it coming out at $20. I suspect the copper alone in the transformer windings costs more than $2.

author: BrianHG
author_rank: Super Contributor
timestamp: February 26, 2018, 09:32:38 pm
content: This is the cheapest I just found at 7$us + Shipping.https://www.jameco.com/z/41A-12-500-Arndt-AC-to-AC-Wall-Adapter-12-VAC-500-mA-2-1mm-Female-Plug_2234185.htmlNow I still need to find European 240v wall-wart as well.

author: Tom45
author_rank: Frequent Contributor
timestamp: February 26, 2018, 09:35:16 pm
content: I was just going to mention Jameco too.They also have a 12 volt 1200 ma supply for the same price:https://www.jameco.com/z/AM-121200A-Arndt-12VAC-1200mA-AC-to-AC-Wall-Adapter-Power-Supply_2167576.html

author: rsjsouza
author_rank: Super Contributor
timestamp: February 26, 2018, 09:36:09 pm
content: Would these guys ship to Canada? It has CSA/UL approval:https://www.amazon.com/12VAC-1200mA-Adapter-Power-Supply/dp/B00B88DUIWAny particular reason why it must be AC? I have seen older equipment have AC wall adapters only because the designer decided to put the diodes and tank capacitor inside the product...

author: BrianHG
author_rank: Super Contributor
timestamp: February 26, 2018, 09:37:21 pm
content: Quote from: Tom45 on February 26, 2018, 09:35:16 pmTake a look at the length of the power chord in that photo...

author: BrianHG
author_rank: Super Contributor
timestamp: February 26, 2018, 09:44:33 pm
content: Getting there, 3.25$ usd.https://www.allelectronics.com/item/actx-1203/12vac-0.33a-wall-transformer/1.html

author: IanB
author_rank: Super Contributor
timestamp: February 26, 2018, 09:45:00 pm
content: Quote from: BrianHG on February 26, 2018, 09:37:21 pmYes, it's actually 6 ft long, but the rest of it is cropped out of view in the picture

author: BrianHG
author_rank: Super Contributor
timestamp: February 26, 2018, 10:00:16 pm
content: Here is the cheapest UK 240v supply at £5.94:https://uk.rs-online.com/web/p/plug-in-power-supply/1391765/
Art of Electronics 2nd Edition vs 3rd Edition - Page 1
Forum section: electronics / beginners

author: nbritton
author_rank: Frequent Contributor
timestamp: October 20, 2015, 03:56:58 am
content: I own a copy of the Art of Electronics 2nd edition and also a copy of the student workbook, but I haven't read it in like 15 years. Would it be worthwhile to buy a copy of the 3rd edition ($93) and reread it, or should I simply reread the 2nd edition that I already own? As far as I know the 3rd edition doesn't have a companion student workbook yet.Another book I'm interested in is "Practical Electronics for Inventors", can anyone recommend this book?I learn best through video instruction, I have a dyslexia that causes me to be a very slow reader, can anyone recommend a video series that covers the same topics as the AoE?

author: fivefish
author_rank: Frequent Contributor
timestamp: October 20, 2015, 05:11:23 am
content: QuoteI have this book.If you don't have access to the Internet, or you don't know how to use Google, this book can be useful for finding some jelly-bean circuit schematics.

author: John_ITIC
author_rank: Frequent Contributor
timestamp: October 20, 2015, 07:02:39 am
content: I have all three books. AOE3 can be a bit terse, not explaining many things. You would need to go to other sources; PEFI is a bit better on explaining the details. Wikipedia and other sources fills in the rest...
Art of Electronics Bad Idea question - Page 1
Forum section: electronics / beginners

author: avector
author_rank: Newbie
timestamp: October 19, 2019, 07:22:43 pm
content: I recently bought Art of Electronics 3rd Edition, which does not have the "Bad Circuits" from the 2nd Edition. In pursing the material and the website, I came across this "Bad Circuit" for a high side power switch using PMOS:https://artofelectronics.net/bckt-high-side_power_switch/I see that the PMOS is going to take a long time to turn off with only ~480uA to increase gate voltage, but I don't see anything fatally wrong with the circuit. Yet everywhere else on the internet I looked used a BJT NPN instead of an NMOS to drive the gate. I was wondering if someone could look up this circuit in the 2nd Edition or if anyone knew more (or saw something obvious I missed)?

author: edavid
author_rank: Super Contributor
timestamp: October 19, 2019, 07:38:48 pm
content: The maximum VGSof the P MOSFET is likely to be exceeded.

author: Zero999
author_rank: Super Contributor
timestamp: October 19, 2019, 08:58:34 pm
content: Fortunately it's easy to fix by adding another resistor.Another alternative is a BJT with an emitter resistor.
Art of Electronics question 1.4 - Page 1
Forum section: electronics / beginners

author: Richardcavell
author_rank: Contributor
timestamp: March 21, 2024, 03:32:15 pm
content: In The Art of Electronics, 3rd edition,I have photographed the question. The next photo is my answer. I am satisfied that it works. But in the third photo, I am alluding to an idea. What I really want to do is what’s in the fourth photo.

author: jwet
author_rank: Frequent Contributor
timestamp: March 21, 2024, 04:19:36 pm
content: I can think of a few ways to do it-A hint- you can always take a subcircuit of parallel R's and make an equivalent single R. If you take N-1 resistors and consolidate them into one R and then add the last- does this give you an idea?

author: golden_labels
author_rank: Super Contributor
timestamp: March 21, 2024, 04:32:12 pm
content: A hint: conductance.

author: Terry Bites
author_rank: Super Contributor
timestamp: March 21, 2024, 05:05:06 pm
content: Legit

author: wasedadoc
author_rank: Super Contributor
timestamp: March 21, 2024, 07:27:02 pm
content: Quote from: golden_labels on March 21, 2024, 04:32:12 pmDid you mean "induction"?https://en.wikipedia.org/wiki/Mathematical_induction

author: ebastler
author_rank: Super Contributor
timestamp: March 21, 2024, 07:34:54 pm
content: Quote from: wasedadoc on March 21, 2024, 07:27:02 pmNo, I don't think that's what he meant. But you got the "Wikipedia" bit right.https://en.wikipedia.org/wiki/Electrical_resistance_and_conductance

author: wasedadoc
author_rank: Super Contributor
timestamp: March 21, 2024, 07:52:39 pm
content: Quote from: ebastler on March 21, 2024, 07:34:54 pmThe OP's question was about the fourth photo. Conductance is at the heart of the first equation in that photo, but I could argue that going from that equation to the second one is mathematical induction.

author: ebastler
author_rank: Super Contributor
timestamp: March 21, 2024, 08:06:52 pm
content: Quote from: wasedadoc on March 21, 2024, 07:52:39 pmWell, once you phrase the problem in terms of conductance, you don't really need to bring out the heavy artillery to see that a+(b+c+d) = a+b+(c+d) = a+b+c+d.

author: golden_labels
author_rank: Super Contributor
timestamp: March 22, 2024, 05:33:19 am
content: In the exercise we read“beginners tend to get carried away with complicated algebra […]. Now is the time to begin learning intuition and shortcuts.”I take that as a suggestion to not use algebraic approach. If one states the problem in terms of conductance, it becomes equivalent to joining small pipes to make a large one.I believe this is something so intuitive, that a child would understand the concept.

author: Smokey
author_rank: Super Contributor
timestamp: March 22, 2024, 05:58:04 am
content: LTSpice
Art Of Electronics - Source for Big Board Dallas: LCD and keypad module? - Page 1
Forum section: electronics / beginners

author: SpannersToSparks
author_rank: Regular Contributor
timestamp: January 29, 2018, 02:11:31 pm
content: HiI believe this topic has been discussed in the past, but I am hoping someone may have since found a neat solution. I have finally got onto building the Dallas "big board" computer in the AoE lab manual, but realise that despite buying all the recommended components (special mounted IC chips and all), there were three little hidden "gotchas" squirreled away in the text and on the aoe site. Those are:An LCD output module on a board of associated electronics which costs $140 from the USA keypad board. The text advises you to check "appendix 14N.20" for a schematic if you want to build it yourself, however there is no such appendix in either volume, and section 14N.20 in the main lab book refers to something else entirely. There is no reference on the site. If I recall correctly there is a keypad in the bundle of parts I bought, though I am not sure if this is related to some other chapter and there's nothing to indicate how to combine it into a proper board.It also recommends using the green "Big Board" breadboard in the text, and the parts list refers to a Global Specialities powered breadboard that costs £340 - the PB-503. However the pictured 'green' board is a completely different layout to the 503 (and neither is it green but that seems the least of the problems), and the alternate 105. He does say you can just use 5 or 6 breadboards, but goes on to assume that you ARE using the "big green" model and that wiring directions will be given accordingly. As I am a beginner, I lack the experience needed to figure out how to bodge together a "6 normal breadboard version" (I was kinda taking the course in order to be taught that kind of thing)Has anyone done the angelic thing and put together a separate guide for this part of the book, perhaps with DIY instructions on how to build the lcd and keypad boards, or even knows where to find the actual "big green breadboard" used?
Artesyn PS-5022-S - Page 1
Forum section: electronics / beginners

author: Lani
author_rank: Newbie
timestamp: November 13, 2020, 11:45:14 am
content: Hey there everyone. Just bought a lot of electronic stuff and in it came with a few tubes of these modules that I can't quite figure out what they are or how I could use it. Any one live in the US and wants a few to play around with I'll send them to ya. It would be nice to know what these are for. I emailed Artesyn and they told me they have no data for this part anymore (obsolete). Any help would be much appreciated. The 4 pins that are bent down (7,8,9,10) are just connected to the two diodes on the board and nothing else. Thanks for looking.Edit - The missing components on the board are two polycarbonate caps that I removed. 100n and 2u2

author: Lani
author_rank: Newbie
timestamp: November 13, 2020, 11:47:09 am
content: Thought I should add a picture of the part when its not destroyed...lol
Articles about "In depth" source of noise explainations (scope probing)? - Page 1
Forum section: electronics / beginners

author: eTobey
author_rank: Super Contributor
timestamp: January 02, 2025, 06:26:33 am
content: Hi,i already spend much time, trying to find actual information, on how noise is exactly generated. To me its not enough, that "big loops catch noise" or "use a short lead". I want to know exactly where the noise is really created. Where is the current flowing that creates the noise? Through which parts?Some learning experiments would be good also. Or maybe there is a good book about it?I found this video, which i deem to have quite some competence in it, but its not an educational video unfortunately:

author: inse
author_rank: Super Contributor
timestamp: January 02, 2025, 07:09:35 am
content: There is also a good brochure from Tektronix covering many aspects of probing, the ABCs of probes:https://download.tek.com/document/02_ABCs-of-Probes-Primer.pdf
Articles available on Hakko site on saving solder iron tips  - Page 1
Forum section: electronics / beginners

author: r90s
author_rank: Regular Contributor
timestamp: October 12, 2012, 05:41:22 am
content: Good articles.....http://www.hakkousa.com/kb/knowledgebaseArticle10322.aspxPDFs at bottom of article.

author: Robgo
author_rank: Newbie
timestamp: January 16, 2014, 07:05:59 am
content: thanks for sharing.Very informative tip care guide.

author: lapm
author_rank: Frequent Contributor
timestamp: January 16, 2014, 07:42:52 am
content: Thanks for shareing.

author: hiddensoul
author_rank: Regular Contributor
timestamp: January 16, 2014, 07:46:29 am
content: Quote from: r90s on October 12, 2012, 05:41:22 amThanks for that, as magazine editor for our local Ham radio club I will include some of these tips
Artifacts when lowering TCXO supply voltage - Page 1
Forum section: electronics / beginners

author: r4ptor
author_rank: Contributor
timestamp: November 30, 2021, 04:15:18 pm
content: Hello guys,I was playing around with a 32MHz TCXO from NDK and Peterman to have a look at the behavior of reduced supply voltage in terms of stability.The test setup was the following:Load_C was left out since my scope probes have 11pF capacitance.You can see, that for 1V8 supply, the waveform looks rather clearbut even a drop of 100mV results in a wave with strange artifactsThe TCXO is still stable and producing the desired frequency, but the waveform looks odd.The crystal itself was soldered on a IC adapter board, the caps were soldered directly on the pins, the load resistor was a normal THT one. The whole setup was put in a breadboard, so some introduced noise was expected.Does anyone has an idea why this "smearing" happens? Shifted trigger, rendering artifacts?Thanks and have a nice day.

author: tkamiya
author_rank: Super Contributor
timestamp: November 30, 2021, 10:35:33 pm
content: What is the the TCXO's design voltage?

author: radiolistener
author_rank: Super Contributor
timestamp: December 01, 2021, 02:36:37 am
content: it looks like amplitude modulation, try to setup slow horizontal resolution on oscilloscope to see low frequency envelope

author: David Hess
author_rank: Super Contributor
timestamp: December 01, 2021, 06:55:48 pm
content: I would guess lack of gain margin in the oscillator when the supply voltage falls, lowering the operating current and thereby transconductance of the oscillator stage. This is particularly a problem with CMOS crystal oscillator stages.Alternatively if the TCXO has a long divider stage, then variation in the supply current might cause enough supply voltage variation to cause something like that.

author: Doctorandus_P
author_rank: Super Contributor
timestamp: December 02, 2021, 12:26:36 am
content: Quote from: tkamiya on November 30, 2021, 10:35:33 pm

author: r4ptor
author_rank: Contributor
timestamp: December 06, 2021, 10:24:43 am
content: Quote from: tkamiya on November 30, 2021, 10:35:33 pmQuote from: Doctorandus_P on December 02, 2021, 12:26:36 amSorry for the late reply, was kind of busy the last days.I think the nominal supply voltage is 1,8VHowever, I had another look at the problem.The main problem was probably, bad triggering.As you can see in the attached screenshots, the artifacts are gone when I improved triggering and the TCXO remained stable (with decreased amplitude of course) down to nearly 1,5V.An additional problem could be the load resistance/capacitance. The circuit I showed above is not specific for this crystal, I just eyeballed it.Also probing it with a normal passive 1:10 probe could of course insert some distorting.To really tackle this precisely i would probably measure with an OPA.But for now, the initial problem was probably really due to triggering. The crystal works down to 1,6V, that's what I wanted to find out.
AS5048A Magnet and SPI questions - Page 1
Forum section: electronics / beginners

author: Joel
author_rank: Newbie
timestamp: April 29, 2015, 12:59:52 am
content: I am going to be implementing an AS5048 Absolute encoder into my project. I am using the AS5048A which is the api one not the B which is the i2c version.I have several questions:In the data sheet it says the magnet holder can not be ferromagnetic, I am connecting it to a steel rod, is steel ferromagnetic? If it depends on the type how would I test it? If it is how much of an insulation should I put between the chip magnet and the steel rod?To daisy chain them together it shows a style I have never seen before and need help with. See the attached image of the datasheet. It looks to me like instead of splicing the 3 SPI pins and adding one slave select pin for each board they are putting the MISO pin of each board to the next pins MOSI until the last board. This is really cool because my project requires a wire tether and the less wires the better. I am specifically confused on how to control them. "MCU shifts n x 16-bit (e.g. READ command FFFFh) through the chain" and "MCU shifts n x 16-bit (e.g. NOP command 0000h)". I think this has to do with bit shifting, I just don't know what it wants me to shift.Would this be better for the micro controller forum?Any help would be greatly appreciated thanks very much,Joel

author: cyr
author_rank: Frequent Contributor
timestamp: April 29, 2015, 03:42:09 pm
content: Shifting simply means to do the SPI transfer, so with N devices in series you would repeat your command (16 bits) N times while keeping the SS signal low. After the first 16 bits are transferred the device starts shifting the bits it has received back out on MISO, propagating the command to the next chip in the chain.Do the same thing again, and out the other end of the chain will come the data bits you wanted - first the ones from the last chip in the chain.Think of each chip as a 16-bit shift register with some added intelligence.

author: mikerj
author_rank: Super Contributor
timestamp: April 29, 2015, 04:14:02 pm
content: Quote from: Joel on April 29, 2015, 12:59:52 amIf it is a mild steel rod, then it is ferromagnetic. Some stainless steels are not magnetic, but this is very easy to test with a permanent magnet.

author: Joel
author_rank: Newbie
timestamp: May 06, 2015, 11:46:02 pm
content: I tested it with a permanent magnet and it is magnetic. How do I insulate the magnet for the sensor from the magnetic steel shaft?
ASIC Charger IC for 1-4 loose NiMH charger - Page 1
Forum section: electronics / beginners

author: Vindhyachal.takniki
author_rank: Frequent Contributor
timestamp: July 27, 2016, 07:04:55 am
content: 1. I am looking for ASIC charger IC for loose 1-4 loose NiMH cells.Looking for replacement for DS2714 in PCB.2. Checked many products for NimH charger. All are for pack.Any product for loose charger? So that individual chargers can be inserted/remove independenly.3. Otherwise I have to see if I can make with microcontroller.

author: Vindhyachal.takniki
author_rank: Frequent Contributor
timestamp: July 29, 2016, 06:34:57 am
content: Many companies have NiMH charger but for pack(series cell connection or parallel) not for loose cells. Ds2714 can do that but I am looking for its replacement.Probably i will replace it with multiple bq2000.
ASIC solution for 20S Li-Ion BMS - Page 1
Forum section: electronics / beginners

author: Vindhyachal.takniki
author_rank: Frequent Contributor
timestamp: November 14, 2016, 01:11:57 pm
content: 1. Battery Management System for 20 Serial cells Li-IOn battery. Each cell voltage range: 2.7V to 4.2V with typical 3.6V.So entire system voltage range is : 54V-84V2. The system has to be complete BMS, i.e:SOC(state of charge), Overvoltage/cell protection, undervoltage/cell protection, Overcurrent protection in charging & discharging, short circuit protection in charge & discharging, over & under protection, cell balancing, communication like RS4853. The best I could get is using combination of TI; bq76930 or this reference design :http://www.ti.com/tool/tida-01093.This dont have gauging or cell balancing. Gauging can be added using external micrcontroller & programming.Many other companies had solutions like intersil but its for balancing only.I am looking some asic for this purpose though. Not one asic but may be combonation of some.4. Had anyone experience in using some stackable system for this kind of application?This is query from my client, I have to see if I can design it with some solution?

author: Paul Price
author_rank: Super Contributor
timestamp: November 14, 2016, 03:18:03 pm
content: Managing 20 individual cells is in itself a problem requiring 20 A-D measurement points and a way to ensure that the measurement voltage dividers are disconnected aren't discharging all the cells after charging.Sure, it could be done with lotsa parts. Maybe a single current sense resistor, a 20 A-D input MCU and probably about 20 power MOSFETS to direct charging/shunts of each cell, then 20 more MOSFETS to switch out the monitoring voltage dividers and some little programming to achieve constant current charging and power MOSFETs to switch in balancing shunt resistors, etc.The idea here would be to charge the whole string in series at a low current and monitor charge progress across each cell to detect charge voltage inbalances/cell failure and to selectively discharge overcharging cells while directing charge current to those cells still not fully charged.And then you could interface the monitoring MCU UART to report back charge data with interfacing to a RS485 chip.Of course you could also just charge/monitor the whole charge process with 20 or so relays to shunt charging batteries as needed.
ask about electric devices - Page 1
Forum section: electronics / beginners

author: huu_tri0101
author_rank: Contributor
timestamp: November 18, 2013, 04:00:53 pm
content: 1. The value of that resistor? How many watt it is ? How we read the code printed on resistor?2. The capacitor's color is yellow, the brandname is ELNA, the printed codes on it are: 10V 16uF, +85*C, S (in a circle) . Is it a special capacitor ?(cause its color is yellow). When replace it with new capacitor what parametter i shoud care (beside Volt and uF). It's used near op-amp.Thank you.

author: madires
author_rank: Super Contributor
timestamp: November 18, 2013, 04:30:30 pm
content: The resistor has 0.22 ohms which is printed nicely. The "J" means +/5% tolerance (please seehttps://en.wikipedia.org/wiki/Resistor#Industrial_type_designationfor the details). If no wattage is marked you have to determine it by the size of the resistor. My guess would be 2W.The cap is a standard electrolytic. If you want to replace it use another one with 16µF and the same or higher voltage rating. The temperature of +85°C gives us the hint that this cap isn't a low ESR one.

author: mariush
author_rank: Super Contributor
timestamp: November 18, 2013, 09:32:56 pm
content: Capacitor is standard 10uF 16v.Feel free to replace with a 105c rated 10uF capacitor, with a voltage rating that can be anything between 16v and.. let's say 50v. The voltage rating doesn't matter as long as it's at least 16v. No need to use low esr capacitors, I would use something like Panasonic FC/FK , Nichicon PW, VZ , united chemicon lxy, ky etcResistor.. by the size it's at least 2w like madires says. You can go with higher wattage ratings.