hybridfree/eevblog-posts huggingface dataset:
What and why is this component across an isolation barrier? - Page 1
Forum section: electronics / beginners

author: AlfBaz
author_rank: Super Contributor
timestamp: September 29, 2014, 11:29:40 pm
content: In thispostis a picture of the internals of an M-131 Maynuo RS232 isolatorThe isolation barrier is across IC2. Is that blue component a cap, a MOV or something else? I cant, for the life of me, figure out what it's doing or why you would put it there

author: Stonent
author_rank: Super Contributor
timestamp: September 29, 2014, 11:33:47 pm
content: It looks like a MOV but is labeled C10 as if it was a capacitor. The IC underneath is likely a optocoupler/optoisolator.

author: AlfBaz
author_rank: Super Contributor
timestamp: September 29, 2014, 11:50:19 pm
content: Ahh, didn't see C10 under the shadowIn that thread they've come to the conclusion its anADUM2201digital isolator.Still don't know why its there. Are they trying to protect the isolator from transients by dumping it onto the pc's ground?

author: lgbeno
author_rank: Frequent Contributor
timestamp: September 29, 2014, 11:54:38 pm
content: It's a Y capacitor, purpose is to allow a high frequency path between the two grounds. It is a typical thing to do in systems to pass emc testing

author: Rufus
author_rank: Super Contributor
timestamp: September 30, 2014, 12:37:02 am
content: Quote from: AlfBaz on September 29, 2014, 11:50:19 pmIt is more likely one of their isoPower isolators (like ADuM5201) which include an isolated DC-DC converter running at 180MHz.Such converters end up being an rf signal generator between the two grounds and it needs to be shorted out with some capacitance to reduce radiation from one ground with respect to the other. On multilayer boards you might get enough capacitance by overlapping the grounds on different layers. If not you have to add capacitance and placed across the isolation barrier it needs to be rated accordingly.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: September 30, 2014, 01:00:32 am
content: The internal monolithic transformers are pretty good already (they use balanced drive), but a cap may help with EMI from the device, or just for external purposes because -- cables resonate, and added capacitance means you get a lower impedance for ferrite beads to work against.Tim
What are classical jelly bean 3v3 to 5v bus tranceiver ICs called? - Page 1
Forum section: electronics / beginners

author: king.oslo
author_rank: Frequent Contributor
timestamp: February 15, 2013, 12:51:54 am
content: Hello,For when I am breadboarding, what is the industry standard 3v3 - 5v tranceiver ICs called? If there is such a thing?For I2C, SPI communication between 5V ICs to 3v3 ICs, for example.Thank you for your time.Kind regards,Marius

author: Skimask
author_rank: Super Contributor
timestamp: February 15, 2013, 01:00:05 am
content: One example of a level translator.https://www.sparkfun.com/products/10403Hundreds of ways to do it...

author: dr_p
author_rank: Frequent Contributor
timestamp: February 15, 2013, 06:52:49 am
content: check this out:http://www.rocketnumbernine.com/2009/04/10/5v-33v-bidirectional-level-converter

author: Nermash
author_rank: Frequent Contributor
timestamp: February 15, 2013, 07:24:51 am
content: I use the term "buffer". Look at 74F125 datasheet.
What are differences between half bridge vs full bridge LLC resonant SMPS ? - Page 1
Forum section: electronics / beginners

author: tigrou
author_rank: Regular Contributor
timestamp: November 19, 2018, 01:30:02 pm
content: Context : I want to buy a new power supply for computer. The two models I am looking at are SeaSonic Focus Gold and Corsair RM750x.I took a look at reviews (hereandhere) and found that both are using LLC resonant topology for primary side.The difference is one is half bridge (2 main switchers), the other is full bridge (4 main switchers).My knowledge about SMPS is limited but from I understand LLC resonant topology (vs simpler design) allow to reduce losses during switching (which should be done when voltage is as close as possible to zero)I am not directly asking which one I should buy, is corsair better than seasonic, .... or other PC stuff (this forum is about electronic in general not PC hardware).What I would like to know is if it make a major difference in terms of SMPS stability and performance.I am a bit surprised the SeaSonic one came with a full bridge as it is (AFAIK) usually used for high power stuff (eg : >2KW).

author: T3sl4co1l
author_rank: Super Contributor
timestamp: November 19, 2018, 06:54:20 pm
content: Right, power is usually the difference. More switches does afford more control options (e.g., phase shift PWM), but it's not obvious if that's used here. (I think it tends not to be used due to EMI reasons, but who knows.)It may allow the savings of some capacitors (half bridge is usually working against a coupling cap to GND, or a cap divider between DC+/-), but at the cost of more drive circuitry, and probably a more expensive controller.Either kind can be made stable and efficient, or unsafe and hot. You'd have to do a deep teardown to figure that out.Tim
What are Dual/Single Panel LCD's? - Page 1
Forum section: electronics / beginners

author: Garph
author_rank: Newbie
timestamp: March 08, 2017, 02:16:22 am
content: Hi All,This is my first time programming a micro-controller and I'm stuck on a hardware definition.The ARM LCD controller Data Sheet says:"The LCD controller can operate in single-panel or dual-panel modes when connected to the associated multiplexed LCD.""In dual panel mode, the DMA FIFOs are filled up in an alternating fashion via a single DMA request. In single panel mode, the DMA FIFOs are filled up in a sequential fashion from a single DMA request."What are single and dual panel LCDs? How do I know which I am using? ARM LCD Controller Data Sheet:http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.ddi0121d/ch01s07s02.html LCD Datasheet:http://www.nxp.com/assets/documents/data/en/supporting-information/RK043FN02H-CT.pdf

author: james_s
author_rank: Super Contributor
timestamp: March 08, 2017, 10:55:50 pm
content: Sounds to me like it's referring to something like the old "dual scan" LCD panels. In those a single display is electrically split up into two smaller displays, reducing the number of elements that have to be scanned and improving the quality of the display.

author: amyk
author_rank: Super Contributor
timestamp: March 09, 2017, 12:17:01 pm
content: The first line makes it sound like the controller can drive either 1 or 2 LCDs, but the second line seems more like it's referring to LVDS "interlacing" where even and odd-column pixels are driven from separate lanes.

author: Buriedcode
author_rank: Super Contributor
timestamp: March 11, 2017, 12:33:24 am
content: It is indeed referring to old 'STN' passive LCD's. Thus the 'monochrome' in the title of that section.These required 4-bit data, data clock, line clock, frame sync etc.. For displays >320x240, such as the 640x480, they were split into upper and lower sections that were updated at the same time, so the data interface was 8-bit: 4-bit upper panel, 4 bit lower. I have one such display and they are remarkably hard to find controllers for! But they are old old, slow and depreciated.As you're using a TFT display then you should be using 'LCD_TFT' bit in the control register.
WHAT ARE Enhanced programmable communications interface (EPCI)? - Page 1
Forum section: electronics / beginners

author: ali6x944
author_rank: Frequent Contributor
timestamp: January 28, 2016, 04:04:00 pm
content: WHAT ARE Enhanced programmable communications interface (EPCI)?

author: Len
author_rank: Frequent Contributor
timestamp: January 28, 2016, 05:03:42 pm
content: A quick google turns up the SCN2661 Enhanced programmable communications interface (EPCI), which is a serial interface chip for old Philips / Signetics microprocessors. Is that what you mean?

author: ali6x944
author_rank: Frequent Contributor
timestamp: January 28, 2016, 05:14:23 pm
content: I DON'T KNOW WHAT DOES EPCI MEANS!could u explain?

author: zapta
author_rank: Super Contributor
timestamp: February 04, 2016, 05:50:19 am
content: Quote from: ali6x944 on January 28, 2016, 05:14:23 pmThings like the SCN2661 are called USARTs (or UARTs) these days. They converts from parallel to serial and vise versa and are useful for implementing serial communication (as in serial or com port). Most modern MCUs come with built in USART(s).https://en.wikipedia.org/wiki/Universal_Synchronous/Asynchronous_Receiver/Transmitter

author: ade
author_rank: Unknown
timestamp: February 04, 2016, 07:45:19 am
content: UART: serial communications, asynchronous onlyUSART: serial communications, asynchronous and synchronousEPCI: (obsolete) was like USART but with a parallel interface on one side (to connect to a microprocessor) and a serial interface on the other sideEPCIs were used when serial ports were very slow, such that they were only used to communicate to external peripherals. Chip-to-chip communications took place on parallel busses.Today we have a number of fast serial interfaces for both internal and external communications, including SSI/SSP, I2C, CAN and USB. Parallel peripheral busses also went out of fashion, replaced with serial ones like PCIe and SATA.

author: ali6x944
author_rank: Frequent Contributor
timestamp: February 04, 2016, 07:11:12 pm
content: THANKS VERY MUCH, GUYS U R THE BEST!
what are some tips to troubleshoot stack valve - Page 1
Forum section: electronics / beginners

author: nyame
author_rank: Regular Contributor
timestamp: November 12, 2022, 05:35:52 am
content: Hello everyonePlease what are some good tips to troubleshooting a stack double acting pneumatic valve ?

author: SeanB
author_rank: Super Contributor
timestamp: November 12, 2022, 06:34:43 am
content: Normally you strip them, clean the spool with something like WD40, dry it off gently and reassemble, which normally does work, as often there is dirt or old polymerised oil that coat parts. Often you will need a service kit for the valve, which is typically all the rubber parts and seals in it, and you simply replace all of them. The kits normally come with a small tube of a NGLI0 synthetic grease that you use to lightly coat all the slides, and all the seals, before assembly, so they do not pinch, and the moving parts can slide easily. If it is a cheap unit, simpler to replace, but if it is one of the better ones, Numatics, Herion, Festo or SMC, they are worth rebuilding if not too badly worn.
What are the beginners reading? - Page 1
Forum section: electronics / beginners

author: Mochaboy
author_rank: Contributor
timestamp: June 06, 2013, 07:55:09 pm
content: I had a sort of epiphany today.I have a burned out circuit board on my bench handed to me by a friend. There's a chipped SMD capacitor on there and I figured if I could just measure that part and order and equivalent, I can fix this. So I bought a capacitance meter and discovered it was a 22pf capacitor.The only other time, I'd come across that was when I was hooking up an atmega 328p to an external crystal and that got me thinking...why 22pf? Heck why any part for that matter.It was high time that I face my demons and start working my way forward sensibly rather than reading one off blog posts and picking up tidbits along the way.Long story short - I'm starting to build my library and after 10 minutes of flipping around on Amazon, I came across this title.http://www.amazon.com/gp/product/0071802363/ref=ox_sc_act_title_1?ie=UTF8&psc=1&smid=ATVPDKIKX0DERWhat are you guys reading?CheersMochahah - no sooner did I hit enter did I notice the 3rd stickyhttps://www.eevblog.com/forum/beginners/electronics-primers-course-material-and-books/dammit!

author: PA0PBZ
author_rank: Super Contributor
timestamp: June 06, 2013, 08:10:27 pm
content: Quote from: Mochaboy on June 06, 2013, 07:55:09 pmNot sure if I read this correctly, but: You have a failed part (chipped = something wrong with it?) and then you measure it and assume that the measurement tells you what the original part was?

author: Mochaboy
author_rank: Contributor
timestamp: June 06, 2013, 08:22:20 pm
content: I left out the part where I have a second working model of that board, so yes, I measured the working board to get the broken component's pf value.

author: PA0PBZ
author_rank: Super Contributor
timestamp: June 06, 2013, 08:30:07 pm
content: Right, that explains a lot!

author: robrenz
author_rank: Super Contributor
timestamp: June 06, 2013, 09:31:19 pm
content: Buy "Practical Electronics for Inventors" 3rd edition only. Hands down the most usefull single book on general electronics and basic electrical. You will thank me after just browsing thru it.Here isis is the table of contents (using the look inside feature on amazon) Just scroll down to see the table of contents.

author: kd7eir
author_rank: Unknown
timestamp: June 07, 2013, 04:59:38 am
content: Quote from: robrenz on June 06, 2013, 09:31:19 pmI completely agree with this suggestion. I actually own two copies of the 3rd edition for some silly reason!
What are the best electronics REPAIR forums? - Page 1
Forum section: electronics / beginners

author: monster_of_electronics
author_rank: Contributor
timestamp: April 12, 2016, 12:51:23 am
content: Any suggestions? (besides EEVBlog)

author: ez24
author_rank: Super Contributor
timestamp: April 12, 2016, 01:07:26 am
content: Almost 20 min and no answers

author: nowlan
author_rank: Frequent Contributor
timestamp: April 12, 2016, 01:42:20 am
content: Probablyhttp://www.badcaps.net/

author: apelly
author_rank: Unknown
timestamp: April 12, 2016, 01:53:36 am
content: Why are you pinging someone else's thread?Anyway, I was going to suggest badcaps too. Might depend on what you want to repair.

author: tautech
author_rank: Super Contributor
timestamp: April 12, 2016, 02:03:35 am
content: https://www.eevblog.com/forum/repair/Dave was initially reluctant to open a Repair board but it's become very popular as the forum stats attest:https://www.eevblog.com/forum/stats/The wealth of knowledge and experience here shouldn't be underestimated.

author: GreyWoolfe
author_rank: Unknown
timestamp: April 12, 2016, 03:17:56 am
content: I have watched Mr Carlson's lab and TRXbench.

author: ArdRhi
author_rank: Contributor
timestamp: April 12, 2016, 03:19:54 am
content: Quote from: GreyWoolfe on April 12, 2016, 03:17:56 amI second the mention of Mr. Carlson's Lab. He's a very nice fellow and has tons of knowledge just dripping out of his ears. His videos are a pleasure to watch!

author: casinada
author_rank: Frequent Contributor
timestamp: April 12, 2016, 03:58:19 am
content: Can you add what country are you from?There are many places when you look to repair electronics. From the eevblog, to yahoo groups to the BadCaps forum, edaboard, etc. Depends on what you want to repair. Some boards are not even in english, probably in russian, czech, chinese, spanish, etc. you have to use a search engine to look for what you want to repair and it might take you to the right place.Last week I was able to repair a Computer power supply that I had sitting in a corner for more than 2 years. I needed something in a hurry to use but I had nothing around so a search took me to badcaps.net, eevblog.com and radiokot.ru. A 100 ohm resistor and 1N4148 diode later the power supply was repaired

author: tautech
author_rank: Super Contributor
timestamp: April 12, 2016, 06:06:03 am
content: Quote from: casinada on April 12, 2016, 03:58:19 amIf you check the OP's profile you'll see he/she is from the US of A and joined us a year ago.Hopefully they'll add a flag to their profile so we can see where they're from at a glance.

author: obiwanjacobi
author_rank: Super Contributor
timestamp: April 12, 2016, 06:14:53 am
content: For music-related equipment I have good experience withhttp://music-electronics-forum.com

author: Radio_Fan
author_rank: Newbie
timestamp: April 12, 2016, 11:47:59 pm
content: Hello--Take a look at...http://repairfaq.org/...Which has been in existence for quite a few years but continues to offer good advice.From a newbie to EEVBlog (who earned his soldering-iron burn scars while repairing tubed radios<g>).73--Radio_Fan
What are the video tutorials for A-Z digital signal processing? - Page 1
Forum section: electronics / beginners

author: Dhanushka
author_rank: Regular Contributor
timestamp: December 11, 2019, 07:23:14 am
content: Dear all,I have learned about digital signal processing including sampling, discreet time signals, z transform etc. But, I don not know how implement these things with software like matlab, labview etc. I am wondering when I got a signal from a circuit, how I can process them into correct signal using suitable processing methods such as FFT spectrum, cepstrum, Q frequency etc on a software except using complex mathematical theories.So, I expect to know what are the available best video tutorials on YouTube from you. It is so better if there are real circuit examples.Thanks.
What are the chances these are YAGEO and muRata - Page 1
Forum section: electronics / beginners

author: Back2Volts
author_rank: Unknown
timestamp: November 06, 2016, 03:27:06 pm
content: I am looking at these two 0603 resistors and MLCC capacitor kits. I like the binders and would be nice if they were known brand/specs. The pictures show labels with YAGEO and muRata. Is this believable ? I have sent a question to the seller about the resistor set, no answer yet.http://www.ebay.com/itm/0603-1-SMD-Resistor-170-Values-50-pcs-value-8500pcs-Sample-Book-Assortment-Kit-/142168261253?hash=item2119e38285:g:~KEAAOSwx2dYGb1Jhttp://www.ebay.com/itm/Black-0603-SMD-Capacitors-0-5pF-2-2uF-90Valuesx50-Sample-Book-Assortment-Kit-/142112184902?hash=item21168bda46:g:soUAAOSwgmJX0nZ1

author: janoc
author_rank: Super Contributor
timestamp: November 06, 2016, 05:14:07 pm
content: I am not quite sure what do you expect people to tell you. Anyone can make a sticker saying "Murata" or "Yageo" and put it on an item. You won't see whether it is genuine from how the cut tape of SMD resistors looks ...Moreover, how do you know that what is in the photo is what you will actually get? eBay/AliExpress/Alibaba/... sellers are known to use "illustrative" images in some cases that have little to do with the actual item being sold.If you have doubts (or need real Murata/Yageo parts), buy from an official distributor and not from eBay, it is that simple.
What are the common failure modes in ICs at low temp.? - Page 1
Forum section: electronics / beginners

author: kamtar
author_rank: Regular Contributor
timestamp: November 23, 2019, 06:35:24 pm
content: While working on a picoballoon and being curious about electronics at low temperatures I came over to information that the first thing to fail in an MCU would be flash and I could add robustness by executing the whole program from RAM.So let's take an example where I have a battery (Li/FeS2) which is rated -40C but I can imagine that it can work for a while in -50C and more too. And then TPS61006 step-up, ARM and SX1276 LoRa module, everything else is expendable.So what can be the main/most common failure mode at around -40/-50C?From my uneducated guess, I'm worried mainly about radio module drifting too much, even sooner than -40C. But now I'm really curious about that flash thing and executing program from RAM; how beneficial it can be in this case.

author: iMo
author_rank: Super Contributor
timestamp: November 23, 2019, 06:57:55 pm
content: Put the stuff into a small box (ie made of polystyrene foam) and it could stay above -40C..

author: David Hess
author_rank: Super Contributor
timestamp: November 23, 2019, 07:01:59 pm
content: The common digital failure I have seen is an analog one. Transistor transconductance drops with temperature which may cause crystal oscillator circuits to fail to start at low temperature if they were not designed with enough excess gain margin.For other problems, two of the design steps I might take is to operate the logic at the higher end of its supply voltage range and at lower clock frequencies to give more timing margin.

author: james_s
author_rank: Super Contributor
timestamp: November 23, 2019, 07:09:36 pm
content: The drifting crystal frequency is probably going to be significant, even at more normal temperatures it can affect those RF modules. Why don't you insulate the circuit to keep it warmer? If you have the power budget you could even ovenize it, it doesn't take much power if it's well insulated. Seems like it ought to be fairly easy to avoid most of the problems in the first place.

author: kamtar
author_rank: Regular Contributor
timestamp: November 23, 2019, 07:18:57 pm
content: Thanks, Yeah I really don't want to overdo it with stuff like heating. I treat it as a fun, fast and cheap project. Asking out of curiosity, and for the future.

author: iMo
author_rank: Super Contributor
timestamp: November 23, 2019, 07:34:16 pm
content: You may calculate the thermal budget - the power dissipated off the electronics and the battery vs. outside temperature at certain altitude, considering, say, 20mm thick polystyrene foam.. Based on the temperature profile you may manipulate the actual duty cycles of the components

author: james_s
author_rank: Super Contributor
timestamp: November 23, 2019, 07:40:09 pm
content: Heating doesn't have to be complicated, it can be something as simple as a resistor connected across the supply. You may be fine just having insulation and using what little heat is already produced by the electronics.
What are the dark rectangles on the logic analyzer waveform? - Page 1
Forum section: electronics / beginners

author: herbkanis
author_rank: Newbie
timestamp: March 10, 2018, 02:52:54 am
content: Hi,Has anyone seen dark rectangles like the ones in the waveform capture I’ve attached?The logic is from an Epson Printer and I’m using a Diligent Discovery 2 to get the waveforms.Thanks for any help,

author: MarginallyStable
author_rank: Regular Contributor
timestamp: March 10, 2018, 04:40:27 am
content: I'm not sure if relevant for your analyzer, but may be glitch detection. Some analyzers have circuitry to detect glitches that are smaller than the instrument's sample period.

author: Paul Rose
author_rank: Regular Contributor
timestamp: March 10, 2018, 05:29:50 am
content: Yes.https://reference.digilentinc.com/reference/software/waveforms/waveforms-3/reference-manualThe online Waveforms manual section 4 ( Main Plot ) point 12:QuoteOn figure 4.1, the corresponding label 12 shows a dark background for a portion of the plot

author: herbkanis
author_rank: Newbie
timestamp: March 10, 2018, 05:32:57 am
content: Both answers are correct. I did a search for "Wavegen" and "Glitch" on marginallystable's suggestion and found the reference that Paul gave.Thanks to you both!Cheers
What are the differences between these 2 fluxes? - Page 1
Forum section: electronics / beginners

author: jamesmith134
author_rank: Newbie
timestamp: April 07, 2014, 01:33:02 pm
content: Hello!I wanted to get a flux paste but found these 2 types: RMA-223 and RMA-218.What is the difference between them? each of them has a specific purpose?Thank you

author: mcinque
author_rank: Unknown
timestamp: April 07, 2014, 07:41:05 pm
content: RMA-223: not properly a mere flux, "pre-alloyedsolder powdersand mildly activated resin paste flux" (fromhttp://www.amtechinc.com/pastes.html)RMA-218: should be a no-clean, high viscosity flux used in reballing

author: nanofrog
author_rank: Super Contributor
timestamp: April 07, 2014, 07:50:57 pm
content: The numbers aren't consistent between manufacturers. What does tend to be more consistent, is the letters R, RMA, and RA that describe the rosin & activation level (R = Rosin, RMA = Rosin Mildly Activated, and RA = Rosin Activated; weakest to strongest cleaning action). What you also need to watch for with paste products, is whether or not it's just flux, or has metal in it (solder paste).Based on what you've indicated, both are Rosin Mildly Activated types. That's all that can be determined without a datasheet or trying it out (ultimately what you'd need to do to test performance).Take a look at the following links:Kingbo's page (RMA-218)Amtech's Datasheet for their RMA-223(.pdf, this particular data sheet = solder paste, not just flux).The Tacky Flux version datasheet (here, .pdf), is just flux.
What are the layout foot print dimensions of SLG59M1599V  - Page 1
Forum section: electronics / beginners

author: Sai teja
author_rank: Regular Contributor
timestamp: January 23, 2019, 11:16:00 am
content: Hello ,I am planning to use SLG59M1599V in an application. But I am unable understand the layout drawing from the datasheet. In layout suggestion, red dotted lines are given around IC foot print. Someone please explain the significance of dotted lines.Please refer image for foot print layout.Datasheet link :https://www.mouser.com/ds/2/665/SLG59M1599r10_12222014-837747.pdfPlease help me in this regard.

author: Rerouter
author_rank: Super Contributor
timestamp: January 23, 2019, 11:19:46 am
content: Left is the shape of the pads on the device, Right is recommend pad area, if your PCB pads match the red dotted rectanges., then you have matched the datasheet land pattern
What are the limitations of this voltage multiplier? - Page 1
Forum section: electronics / beginners

author: nsled
author_rank: Contributor
timestamp: April 28, 2023, 11:48:28 am
content: Digging through a shed this come up, what would you do with it?It's a 3 stage full wave multiplier, constructed with 9 10KV 0.1uF caps and 12 10KV 1A diodes. I just checked the prices and it's about $400US worth of components.What would this even be good for and what limitations does it have? I've looked at multipliers on youtube but they are always constructed with much smaller components.Am I right in thinking this will be limited on the frequency it can be used at due to larger caps? What advantage do larger caps hold in this configuration? Does 10KV mean I can hook a 10KV neon transformer (for a bit shy of 60KV?) up to it or does the rating mean you should leave a margin below it?

author: m k
author_rank: Super Contributor
timestamp: May 06, 2023, 04:03:52 pm
content: I'd say that everything open and 10kV is in the category of don't ask or don't do.To get more answers you must convince others that you're not about to kill your self.Or at least nobody around is not keen to assist you.

author: coppercone2
author_rank: Super Contributor
timestamp: May 06, 2023, 04:10:02 pm
content: It's a high voltage physics experiments.Unless you can afford thick lexan for fixture, HV wire, new probes, etc then don't botherThe scary part is hearing about HV and cost put together. I would call it a cheap ass voltage multiplierAnd uh before you use it, that thing should be super clean. Like detailed
...What are the new user limitations again? - Page 1
Forum section: electronics / beginners

author: Mawson
author_rank: Newbie
timestamp: April 17, 2013, 01:30:05 pm
content: I have searched around for them, but seen nothing. Where are they hiding??

author: Simon
author_rank: Unknown
timestamp: April 17, 2013, 01:31:40 pm
content: If you mean user to the forum I'm not sure and they are not published. What are you having problems with ?

author: Mawson
author_rank: Newbie
timestamp: April 17, 2013, 02:15:57 pm
content: I had tried to post a topic over in the projects, designs, and technical stuff forum, and as I recall (its kinda fuzzy...) It said I wasn't allowed to post there. I'll try again.Edit: Its working now, I must have just derped something up.

author: GeoffS
author_rank: Unknown
timestamp: April 17, 2013, 02:22:52 pm
content: As far as I'm aware, there should be no restrictions on you creating a new thread.Let us (moderators) know if you have problems.
what are the odds that this would  by a very loooonng shot work? - Page 1
Forum section: electronics / beginners

author: 3roomlab
author_rank: Frequent Contributor
timestamp: October 06, 2014, 12:03:46 pm
content: its a ... trashy mod of a camera flash auto-trans ... and i might have a 3:3:7000 transformer coming (though circuit is 12500) ...Vin 6v, Vout (simulated no load) 24kV (Q drive 1.26v)(i must be kidding myself)RGP02-20E = 2kV reverse V each

author: rs20
author_rank: Super Contributor
timestamp: October 06, 2014, 12:16:38 pm
content: Just a little critique; this diagram would be a lot easier to follow if you used ground and V+ labels instead of drawing them explicitly as wires. I've spent a couple of minutes looking at the circuit and I can't even begin to understand it. I'm sure other people with more experience with this sort of thing will be able to decode it, though.

author: 3roomlab
author_rank: Frequent Contributor
timestamp: October 06, 2014, 12:22:26 pm
content: oh yes lol my bad ... the green line is the V+ ... the Gnd is kinda the back "end" of that string of diodes lol ...but i suspect the simulator simulated the circuit wrongly ... because the "boosted" voltage is suppose to be negative, but somehow, i had to reverse the position of diodes and ... i dont think it should give a positive voltage ...

author: tggzzz
author_rank: Super Contributor
timestamp: October 06, 2014, 03:33:11 pm
content: Quote from: rs20 on October 06, 2014, 12:16:38 pmThat's a two-edged sword. With the diagram as drawn, at least you can find everything that is connected to ground simply by following the wire. If only ground symbols were used, it would be easy to miss one if you didn't look in the right place. While that may be unlikely with a small diagram and for the ground, for signals on a large multi-sheet diagram it becomes a significant pain and source of error.In practice the middle way is often best: all subsections in a section of the diagram (e.g. amplifier, filter, driver, etc) have their grounds connected together so that you can see the unit. But separate subsections have separate ground symbols.
What are the "planner diffused PNPN devices" ? - Page 1
Forum section: electronics / beginners

author: sdancer75
author_rank: Frequent Contributor
timestamp: January 17, 2020, 03:09:06 pm
content: Hi,I have an XL1225 medium power low voltage transistor which the datasheet description says that : "The XL1225/ML1225 silicon controlled rectifiers are highperformance planner diffused PNPN devices. These parts are intended for low cost high volume applications. ".Definitely, I didn't understand what it really says.So, my question is what exactly is doing this type of transistor & where are they used?Regards,

author: RoGeorge
author_rank: Super Contributor
timestamp: January 17, 2020, 03:25:13 pm
content: That's not a transistor, it's athyristor, sometimes called SCRhttps://en.wikipedia.org/wiki/Thyristor
What are these? - Page 1
Forum section: electronics / beginners

author: nagz
author_rank: Contributor
timestamp: July 19, 2025, 08:42:52 pm
content: Hi folks,Probs an ultra noob question, but what are these quarter circle “pads” on this GHz amp?Cheers

author: madires
author_rank: Super Contributor
timestamp: July 19, 2025, 09:16:31 pm
content: Lowpass filters. Please seehttps://en.wikipedia.org/wiki/Distributed-element_filterfor more information.

author: Analog Kid
author_rank: Super Contributor
timestamp: July 19, 2025, 09:35:42 pm
content: Quote from: madires on July 19, 2025, 09:16:31 pmInductive, right? They don't look capacitative.

author: nagz
author_rank: Contributor
timestamp: July 19, 2025, 09:39:22 pm
content: Can these be inputted onto Kicad?

author: Doctorandus_P
author_rank: Super Contributor
timestamp: July 20, 2025, 12:17:54 am
content: Quote from: nagz on July 19, 2025, 09:39:22 pmYes:PCB Editor / Place / Add Microwave ShapeThe way these act is a bit "unusual", as they create a new footprint from scratch. If you want to attach a schematic symbol to this footprint, the best order of action is probably:Create the "Microwave shape".Hover over it, pressetoedit it's properties.Click on:Edit in footprint EditorIn the footprint editor, save it to a library.In the schematic editor, add a link to the footprint you just saved.

author: radiolistener
author_rank: Super Contributor
timestamp: July 20, 2025, 01:25:10 am
content: These are microstrip radial stub resonators.

author: madires
author_rank: Super Contributor
timestamp: July 20, 2025, 10:26:22 am
content: Quote from: Analog Kid on July 19, 2025, 09:35:42 pmTransmission line magicLecture -- Radial Stubs:BTW, waveguide stub filters work the same way.

author: nagz
author_rank: Contributor
timestamp: July 20, 2025, 11:18:29 am
content: This is excellent,Thank you for posting.
What are these buttons called? - Page 1
Forum section: electronics / beginners

author: captainscarlet
author_rank: Contributor
timestamp: November 01, 2014, 05:59:40 pm
content: Hi all,What is the name of the buttons used in this image?http://pixel.brit.co/wp-content/uploads/2013/03/9-Pop.jpgIt's like the buttons are mounted onto a pcb, then covered with a flexible plastic that has all the graphics printed on it. They don't seem to be capacitative as there is some movement in the button.Can someone please can give me a name or a link on where to buy them?

author: rolycat
author_rank: Super Contributor
timestamp: November 01, 2014, 06:32:16 pm
content: It's called a membrane keypad.The keypad pictured can be picked up on eBay complete with the RGB LED controller module for a few dollars/pounds. Search for 'RGB controller' and you'll find dozens.

author: German_EE
author_rank: Super Contributor
timestamp: November 01, 2014, 07:29:06 pm
content: If you want individual switches they are also known as 'Dome' switches. A metal dome is soldered to the pcb in three places with contacts underneath.

author: captainscarlet
author_rank: Contributor
timestamp: November 01, 2014, 07:50:12 pm
content: That's perfect. Thanks very much!
What are these buttons ? - Page 1
Forum section: electronics / beginners

author: FreedOhm
author_rank: Newbie
timestamp: July 07, 2014, 05:21:07 pm
content: I was hacking my microsoft sidewinder and opened the handle. I found 2 buttons that have a nice feel and look. They look like tactile buttons but are full black and feel like cherry mx switches. I'll try add pics but they are too large. Thanks for your help!

author: JOERGG
author_rank: Contributor
timestamp: July 07, 2014, 11:51:27 pm
content: For Windows easy toolhttps://imageresizer.codeplex.com/
What are these components? - Page 1
Forum section: electronics / beginners

author: AlxDroidDev
author_rank: Frequent Contributor
timestamp: November 25, 2015, 04:37:10 pm
content: The pics below are from a board taken from a fax machine.The components I need help identifying are the ones looking like tiny vacuum tubes, but with only 2 legs. They are 13mm tall (not including the legs) with a diameter of 5.5mm. Their legs are in holes that seem to be 200mil apart (~5mm)They have the lines "351M" and "TM1 J" on them. The light grey socket near them is a RJ11 socket. The small rectifier bridge marked Z61D on one of the pics is just a tad shorter than an optocoupler, and the same width.I have no idea what these components are, since I've never seen one of these before (that I can recall).Thank you.

author: bktemp
author_rank: Super Contributor
timestamp: November 25, 2015, 04:40:06 pm
content: Those are gas discharge tubes, used for overvoltage (lightning) protection.

author: Andy Watson
author_rank: Super Contributor
timestamp: November 25, 2015, 04:45:51 pm
content: Voltage surge suppressors. Some form of gas-discharge bulb - not unlike a neon indicator.Similar to these:http://www.cdiweb.com/datasheets/okaya/1p132-133rac6.pdf

author: AlxDroidDev
author_rank: Frequent Contributor
timestamp: November 25, 2015, 04:47:59 pm
content: Quote from: bktemp on November 25, 2015, 04:40:06 pmQuote from: Andy Watson on November 25, 2015, 04:45:51 pmThank you!
What are these components? and how to read their values? - Page 1
Forum section: electronics / beginners

author: Azhar
author_rank: Regular Contributor
timestamp: December 11, 2013, 04:35:36 am
content: What are these components? they look like a transistor with two of its legs been shorted!and how to read their values? it seems like they have colour coding of some sort!

author: bxs
author_rank: Regular Contributor
timestamp: December 11, 2013, 05:07:46 am
content: My first bet would be some kind of diode.You should give more info, from where did you got those, do you have pictures, etc...

author: minime72706
author_rank: Frequent Contributor
timestamp: December 11, 2013, 05:34:43 am
content: I've seen pretty standard transistor values with color bands on them that I did not understand. One thing that the strange connection of the 2nd and 3rd pins implies is that it's maybe a "current regulator diode", specifically a ghetto-rigged one.Pretend the pins 1 through 3 are source, gate and drain of a MOSFET or JFET. Connecting the gate and drain of a FET makes a diode-connected device which will attempt to keep a constant drain current. You could try testing it, but I would be careful if you don't want to damage them.EDIT: Upon a quick closer inspection it appears that the middle lead was cut manually and the 2nd and 3rd pin bridged with solder. Can you confirm this? It kind of supports my ghetto-rigged current-regulator idea.

author: Simon123
author_rank: Regular Contributor
timestamp: December 11, 2013, 01:52:12 pm
content: Those are varicap diodes.
what are these IC's? - Page 1
Forum section: electronics / beginners

author: Deactivated-1
author_rank: Frequent Contributor
timestamp: March 20, 2020, 05:14:39 am
content: I found these IC's that I can't find any information on:MN1222CA (matsushita dated 65' 6)MN6840C (matsushita dated 67' 8 )MN1844PC (matsushita dated 66' 1)MN1221C (matsushita dated 67' 1)6E1 JHN613128PN31 japan (don't know the manufacturer)6C4 THD74LS373P (also don't know the manufacturer)6G2 4HD14538BPGD3 THD14001BP6F4 4HD14093BP6G3 4HD14584BP2904DCJRC6022 (perhaps LM2904 made by JRC)

author: magic
author_rank: Super Contributor
timestamp: March 20, 2020, 09:18:22 am
content: HD is Hitachi and simply searching their names without the BP suffix seems to find some datasheets. They appear to be logic ICs and possibly clones of similar MC parts from Motorola / OnSemi. HD74LS373P is likely 74LS373, whatever that would be.The last one may indeed be NJM2904.

author: engrguy42
author_rank: Frequent Contributor
timestamp: March 20, 2020, 11:47:47 am
content: Here's the datasheet for the Motorola 74LS373 latch:https://ecee.colorado.edu/~mcclurel/sn74ls373rev5.pdf

author: engrguy42
author_rank: Frequent Contributor
timestamp: March 20, 2020, 12:11:59 pm
content: Also, you might check Panasonic discontinued automation relays for the "HD1" devices. Looks like the HD1 relays were replaced by HY1 part numbers and discontinued in 2006?Oh wait, you said they're IC's?Nevermind...

author: amyk
author_rank: Super Contributor
timestamp: March 21, 2020, 12:57:10 am
content: I know Google is increasingly a piece of shit for searching part numbers, but you could try a little harder...Quote from: ELS122 on March 20, 2020, 05:14:39 amClick on the links(If anyone knows what the '6840 and '1844 were scanned from, I'd love to find the whole thing.)No luck with the '1221 nor '1222, but I think the info is out there...

author: amyk
author_rank: Super Contributor
timestamp: March 21, 2020, 08:44:39 pm
content: I found this (attached) for MN1221 - "16-channel A/D converter" - but unfortunately not much more info than that.It also shows just how unpredictable Matsushita/Panasonic part numbers are.According tohttp://www.maxdat.eu/_data/15=Letoltesek/Hejetesito%20Tablazatok/Pana%20product%20guide.pdfthe '1222 is a memory, but no more info either.Without their databooks from the late 80s, it's almost impossible to find more information about them.
[Answered] What are these little metal clips? [perfboard connection tags] - Page 1
Forum section: electronics / beginners

author: Whales
author_rank: Super Contributor
timestamp: September 28, 2019, 02:22:36 am
content: Smallest subvisions of the scale are mm.Found this in an old box from Zephyr, 70 Batesford Road, Chadstone, S.E.10 Melb. Victoria. The item part number had faded off the box.One side has teeth, the other does not. The teeth don't seem aggressive enough nor the metal strong enough to make insulation-piercing vampire taps.

author: vk6zgo
author_rank: Super Contributor
timestamp: September 28, 2019, 02:47:32 am
content: Quote from: Whales on September 28, 2019, 02:22:36 amThey look like the connecting tags used with the old style perf board (called matrix board back then).It had no copper, just a sheet of perforated phenolic.The connections were made point to point on the bottom side of the board, & components on the top side.They were also sometimes used as termination points for external wiring on normal PCBs.I think the serrated part (which was not common) was so you could make temporary connections.
what are these mechanical led switches called? - Page 1
Forum section: electronics / beginners

author: Deactivated-1
author_rank: Frequent Contributor
timestamp: February 02, 2020, 07:09:55 am
content: I am just fascinated by the switched on my Elta 8971 graphic equalizer.they have buttons on the top/bottom and they have LEDs that show the "position"it would be awesome if I can find ones that I can buy for not too expensive price.

author: ataradov
author_rank: Super Contributor
timestamp: February 02, 2020, 07:22:43 am
content: Based on the pictures I could find, they are clearly custom made.I don't think there is a standard component that looks or functions like that.

author: ataradov
author_rank: Super Contributor
timestamp: February 02, 2020, 07:46:26 am
content: The labels on the buttons are custom labeled, for sure. It looks like those things come as an assembly, but I'm not really sure they are not custom. It would be nice to see how those things are designed up close. But I really would not expect to actually find them.Also, is not Realistic a private label brand from Radio Shak? In this case all they did is order the units with custom branding.

author: ebastler
author_rank: Super Contributor
timestamp: February 02, 2020, 08:17:37 am
content: These look like LED bargraphs to me (which, of course, are available as preassembled units), plus two pushbuttons with custom-printed caps. I would expect each of these controls to consist of three separate components, soldered to the front panel PCB.Have you taken itapaartyet?

author: ataradov
author_rank: Super Contributor
timestamp: February 02, 2020, 08:19:56 am
content: In the the video you can see that each unit is a separate sub-assembly. But yes, it looks like a standard LED bar graph and a couple buttons. Given how big they are, I also expect some additional logic on the same assembly.

author: ebastler
author_rank: Super Contributor
timestamp: February 02, 2020, 08:24:50 am
content: Thanks for the photos. The first one shows the switch unit nicely, and it's a surprise indeed.That looks more like there is a mechanism inside, where the switch/LED unit mechanically remembers the current setting. Hence, they would be relatives of these BCD thumb switches, with an LED bar added instead of the mechanical state display:

author: ebastler
author_rank: Super Contributor
timestamp: February 02, 2020, 08:34:57 am
content: Quote from: ELS122 on February 02, 2020, 08:19:20 amElta was a German brand, active from 1968 to 2010, but according to Wikipedia has only ever been an importer of Asian-made devices. Maybe they went to the effort of creating decent German documentation including schematics?https://de.wikipedia.org/wiki/Elta_GmbH(in German)
What are these oscilloscope lightbulbs? - Page 1
Forum section: electronics / beginners

author: chucrut
author_rank: Newbie
timestamp: July 08, 2018, 01:57:44 am
content: Hello,I have an analog oscilloscope with no trace. I was checking the problem and found these two "lighbulbs" near the crt socket. I tested conductivity and they are not electrical conductive inside. They dont have visible filament.Any ideas what are this "lightbulbs"?. Maybe they are burned because they are not conductive inside?. Maybe they are something more sophisticate?Many thanks!Agustin

author: ataradov
author_rank: Super Contributor
timestamp: July 08, 2018, 02:08:43 am
content: They are neon bulbs, they are supposed to be open.They specifically look like very classical NE-2 bulbs.They can have multiple uses in a circuit, so you would need to provide more context for where they are located on the board. Most likely they serve as some sort of protection.

author: chris_leyson
author_rank: Super Contributor
timestamp: July 08, 2018, 02:13:46 am
content: They are neon lamps used to generate a fixed voltage drop in the CRT resistive biasing chain. Typical breakdown voltage might be 60V to 90V depending on the lamp used. Like ataradov said, it all depends how they are used in the circuit but as they are located near the CRT socket they are most likely used for protection.

author: David Hess
author_rank: Super Contributor
timestamp: July 08, 2018, 02:41:09 am
content: In oscilloscope CRT circuits, the neon lamps usually serve as low leakage low capacitance shunt protection to prevent the grid to cathode and heater to cathode voltages from exceeding their maximum limits. Since the cathode voltage is in the range of -2000 to -3000 volts, this is pretty important. Often they will flash when power is applied or removed.Tube based oscilloscopes may use them for the same purpose at various points.In cheap designs, they might be used as voltage references.

author: james_s
author_rank: Super Contributor
timestamp: July 08, 2018, 03:37:34 am
content: They were fairly common in CRT computer monitors and TVs too, for the same purpose of shunting HV to prevent arcs in the electron gun from damaging the electronics. They only ever light if an arc takes place.

author: IconicPCB
author_rank: Super Contributor
timestamp: July 08, 2018, 04:51:59 am
content: Seen in some older designs as indicators that the trace is way off screen.

author: james_s
author_rank: Super Contributor
timestamp: July 08, 2018, 04:28:49 pm
content: Quote from: IconicPCB on July 08, 2018, 04:51:59 amThose wouldn't be on the CRT socket though, they'd be in the front panel.