hybridfree/eevblog-posts huggingface dataset:
Does anyone have the AFSCP 800-27 "Part Derating Guideline" document (1983)? - Page 1
Forum section: electronics / projects

author: LeeCross
author_rank: Newbie
timestamp: July 05, 2024, 07:22:41 pm
content: Does anyone have a PDF copy of AFSC Pamphlet 800-27 "Part Derating Guideline", 5 Dec. 1983? It is an old military document for derating electronic components.I plan to perform parts derating for a simple circuit design based on this guideline, but I only have a document thatsummarizesthis guideline - not the original document itself. I've spent hours searching for it with no luck. Any help obtaining this document is appreciated.
Does anyone have USB A male dimensions for making a pcb that plugs in... - Page 1
Forum section: electronics / projects

author: alank2
author_rank: Super Contributor
timestamp: August 03, 2017, 12:55:10 am
content: I have a project where the USB jack (A female) has only 3/16" of space before it hits a case edge so I want to make a micro pcb that plugs into the slot and just has a 4x1 100mil pin header on the very edge of where the pcb sticks out of the jack. Is there official dimensions somewhere for this?

author: alm
author_rank: Super Contributor
timestamp: August 03, 2017, 01:08:29 am
content: You can find the official USB specifications onthis page. If you want backwards compatibility with USB 2, you should probably usethese.Download the ZIP file, open the usb_XX.pdf file inside of it (usb_20.pdf for the USB 2.0 specs), and go to section 6.5.4 (page 99) for the USB 2.0 version, probably something similar for USB 3.1. It has the full mechanical drawings including tolerances. Should be everything you need.

author: alank2
author_rank: Super Contributor
timestamp: August 03, 2017, 01:15:32 am
content: Thank you; downloading it now!
Does anyone have used Chinapcbone?  - Page 1
Forum section: electronics / projects

author: jealcuna
author_rank: Contributor
timestamp: February 18, 2020, 05:05:07 pm
content: Does anyone have usedhttps://www.chinapcbone.com/for mass production of PCB with assembly service?I have used "PCBWAY", but they say 60 to 70 days for my work, a PCB with 50 SMD components for 1500pcs. So, this brings me to chinapcbone which gives me a cheaper price but I can not find any review or experience.
Does anyone here have a baidu.com account that can download some files for me? - Page 1
Forum section: electronics / projects

author: cryptol
author_rank: Newbie
timestamp: June 03, 2022, 01:36:42 pm
content: Hello,Does anyone here have a baidu.com account that can download some files for me? I am form the USA, and it seems impossible to get a baidu.com account.Thanks!Kyra

author: adamseddon24
author_rank: Newbie
timestamp: June 07, 2022, 11:21:26 am
content: have you tried using a vpn?
Does anyone know any cold junction compensator that work at 2V?  - Page 1
Forum section: electronics / projects

author: mimmus78
author_rank: Unknown
timestamp: May 20, 2015, 09:59:52 am
content: I'm searching one of this chip that you can attach one or more K type junction for measuring temperature.It seems I cannot find any chip that works down to 2V ... do someone here know if it it exists?

author: Dago
author_rank: Frequent Contributor
timestamp: May 20, 2015, 03:35:43 pm
content: Quote from: EmmanuelFaure on May 20, 2015, 12:53:58 pmNot really what the OP asked for. Thermocouple are usually used for high temperatures like multiple hundred degrees, I challenge you to find a suitable analog temperature sensor for those temps

author: Pjotr
author_rank: Frequent Contributor
timestamp: May 20, 2015, 04:18:22 pm
content: A K-sensor has a tempco of about 41 uV/degK at 25 degC, a simple silicon diode app. -2.1 mV/degK. So you have to scale down the tempco of the silicon diode to match that of the thermocouple by a resistive divider and invert the output. Google for "Cold junction compensator" and tons of examples come up how to do that.

author: macboy
author_rank: Super Contributor
timestamp: May 20, 2015, 04:38:26 pm
content: Quote from: Dago on May 20, 2015, 03:35:43 pmThe "cold junction compensator" will be at room/ambient temperature, not at the hot side. It is used to add an offset to the thermocouple reading since the thermocouple tells you only the difference between the hot (measuring) side and the junction (ambient) side. To get the temperature, you need to add the junction temperature.
Does anyone know of a 0.3mm pitch BGA or WL-CSP or anything with a 0.3mm pitch? - Page 1
Forum section: electronics / projects

author: billthebuilder
author_rank: Contributor
timestamp: November 17, 2015, 01:23:45 am
content: I need one for testing a PnP machine. It's very hard to hunt something down just by package, so does anyone know of anything with a 0.3mm pitch? BGA preferred. Or clues where to look?Thanks!

author: georges80
author_rank: Frequent Contributor
timestamp: November 17, 2015, 01:47:54 am
content: http://www.topline.tv/Pitch.htmlSmallest 'real' part I've designed with so far was 0.5mm BGA (eMMC chip) and that was 'fun' already for my pcb layout contractor, hate to imagine 0.3mm pitch and trying to route stuff out from the middle.cheers,george.

author: amyk
author_rank: Super Contributor
timestamp: November 17, 2015, 08:44:45 am
content: Quote from: georges80 on November 17, 2015, 01:47:54 amI have a feeling that the prices for those are going to be either  ridiculously expensive, even more so than regular ICs, since they're quite specialised parts, or  ridiculously cheap, like resistors or other passives, since the NRE is basically zero.

author: thesgoat
author_rank: Contributor
timestamp: November 17, 2015, 08:59:13 am
content: Smallest I have used is 0.4mm pitch (BGA) - WM5102ECS/RCT-ND

author: AndyC_772
author_rank: Super Contributor
timestamp: November 17, 2015, 10:14:41 am
content: I'm sure I have one here... somewhere...

author: vector31337
author_rank: Newbie
timestamp: November 17, 2015, 10:56:11 am
content: U2 ic

author: Scrts
author_rank: Frequent Contributor
timestamp: November 17, 2015, 10:58:28 am
content: Lattice have some ultra small FPGAs with 0.35mm spacing:http://latticesemi.com/Products/FPGAandCPLD/iCE40Ultra.aspx

author: ConKbot
author_rank: Super Contributor
timestamp: November 17, 2015, 01:37:40 pm
content: 0.3mm pitch, oof. Theres a big difference between 0.5 and 0.4, I cant even imagine how much swearing I'd do at something 0.3mm

author: AndyC_772
author_rank: Super Contributor
timestamp: November 17, 2015, 02:30:41 pm
content: An 01005 size component is 0.4 by 0.2mm, would that do?

author: exmadscientist
author_rank: Frequent Contributor
timestamp: November 17, 2015, 03:15:52 pm
content: Quote from: AndyC_772 on November 17, 2015, 02:30:41 pmThis is the route I'd go. Saying "We can place 01005s successfully!" is more commercially valuable than saying "We can place 0.3mm pitch BGAs!" as there's a lot more demand for 01005s. I've looked through my part history, and the smallest I've placed lately are 0.35mm pitch devices, which are reasonably common. (ESD filters, single-gate logic, and others favor that pitch. Basically anything with a significant sales potential into cell phones.) TI don't even make any 0.3mm pitch packages as far as I can tell -- they have two drawings on the books (YHC and YHD) but no active products with them; YHD doesn't even have a publicly available drawing. 0.35mm, in contrast, has loads of parts available.
Does anyone know of a part like this... - Page 1
Forum section: electronics / projects

author: alank2
author_rank: Super Contributor
timestamp: March 05, 2014, 01:27:34 pm
content: Hi,I'm not sure where to look at digikey, but I'm looking for a wire to breadboard pin style connector. A machined round pin with a diameter of 0.025" would be ideal for the breadboard side and a solder cup or crimp for the other side (bare wire).Similar to this but with a smaller pin - I think this is a DB connector pin 0.063" diameter...Thanks,Alan

author: Bored@Work
author_rank: Super Contributor
timestamp: March 05, 2014, 06:50:06 pm
content: Ready-made wires won't do? Because they can be had dirt-cheap on eBay.

author: N2IXK
author_rank: Frequent Contributor
timestamp: March 05, 2014, 07:24:22 pm
content: Look into crimp pins for MIL-C-38999 series connectors.

author: calexanian
author_rank: Super Contributor
timestamp: March 06, 2014, 05:29:39 am
content: Looks like a D Sub male crimp pin. They are cheap and all over. I bought a bag of like 250 and a tool to crimp them for like 50 bucks all together on amazon some time back. The tool was the most expensive part cause it was a nice one. It had little tiny ball points inside that made the crimp. Very strong.

author: alank2
author_rank: Super Contributor
timestamp: March 13, 2014, 01:17:58 pm
content: I ended up getting these from Digikey :http://www.digikey.com/product-search/en?x=0&y=0&lang=en&site=us&KeyWords=626-1083-nd15.6 cents each for a hundred of them.They fit a breadboard nice and are round and smooth and also fit the wires I wanted to crimp/solder them onto easily as well. I also used some hot air to shrink some tube around them.I wanted to take a bare wire harness for the logic16 I ordered and put pins on it so I could just plug it directly into any breadboard project I have going, it turned out great.Thanks,Alan
Does anyone know the part number for this connector? - Page 1
Forum section: electronics / projects

author: AMyatt
author_rank: Contributor
timestamp: May 30, 2014, 06:01:42 am
content: Hi there,I need to buy a replacement connector for a product repair but can't find the part.Does anyone know the part number or manufacturer of the following part?I have searched Molex connectors for an hour looking through pictures but nothing matched.(Bottom left, 6 pin)(Bottom centre, 6 pin)Thanks

author: Sparc
author_rank: Contributor
timestamp: May 30, 2014, 06:15:29 am
content: You might try searching Digikey or other distributers. They aggregate many different manufacturers in one search. If you can get an accurate measure on the pin size and pitch you should be able to narrow it down.

author: AMyatt
author_rank: Contributor
timestamp: May 30, 2014, 06:36:03 am
content: Thanks Sparc.I think I have found it, after I remembered that the manufacturer of this gear favours Foxconn parts.I believe it is a HD5106 (http://www.fit-foxconn.com/catalog/spec/ProductSpec/hd5105e.pdf).Before trying to order one I will measure the actual part and compare to the datasheet to confirm (I'm away from home at the moment).
Does anyone know the part number for this inline wire connector? - Page 1
Forum section: electronics / projects

author: Puffie40
author_rank: Regular Contributor
timestamp: May 09, 2024, 04:05:51 pm
content: See the attached image - It connects to a JST PH connector and has male pins, but does not appear in the JST PH datasheet. Despite this, it appears consistently in Asian electronics. Any thoughts?

author: HwAoRrDk
author_rank: Super Contributor
timestamp: May 10, 2024, 08:39:24 am
content: It's probably a variation that JST themselves don't make, but Chinese clone manufacturers have come up with.From a brief search, these seem to be a match:https://www.lcsc.com/mobile/product-detail/Housings-Wire-To-Board-Wire-To-Wire_DLL-PH-2R_C20598779.htmlhttps://www.lcsc.com/mobile/product-detail/Housings-Wire-To-Board-Wire-To-Wire_HCTL-HC-PH-2EY-05_C20417768.htmlActually, perhaps JST PNI series is the wire-to-wire that mates with PH? Looks fairly similar.https://www.lcsc.com/mobile/product-detail/Housings-Wire-To-Board-Wire-To-Wire_JST-PNIRR-02VF_C594849.html

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: May 10, 2024, 10:58:48 am
content: Quote from: HwAoRrDk on May 10, 2024, 08:39:24 amthe latch detail looks different

author: HwAoRrDk
author_rank: Super Contributor
timestamp: May 10, 2024, 11:14:46 am
content: Quote from: mikeselectricstuff on May 10, 2024, 10:58:48 amAh, you're right. Was difficult to tell from the pictures, I was looking on mobile.

author: Puffie40
author_rank: Regular Contributor
timestamp: May 10, 2024, 05:50:14 pm
content: Quote from: HwAoRrDk on May 10, 2024, 08:39:24 amThanks for the LCSC links! I wanted to put this connector into a RapidHarness drawing, but I didn't want to use something that I could not provide a source or datasheet for.
Does anyone know what this logo means (on a PCB) - Page 1
Forum section: electronics / projects

author: bjornag
author_rank: Newbie
timestamp: May 08, 2015, 03:30:39 pm
content: Looks like SL to me but i don´t know if its abbreviations for some manufacturer . any help kindly accepted

author: phenol
author_rank: Regular Contributor
timestamp: May 08, 2015, 04:19:25 pm
content: it looks like a rabbit assuming standby position

author: bjornag
author_rank: Newbie
timestamp: May 08, 2015, 06:08:35 pm
content: I found out which company owns this logohttp://www.c-print.com/index.html

author: German_EE
author_rank: Super Contributor
timestamp: May 08, 2015, 09:27:35 pm
content: Strange, as soon as I saw that image I thought 'Scotland'.http://www.itraveluk.co.uk/images/maps/scotland-map.gif

author: best man
author_rank: Newbie
timestamp: May 16, 2015, 09:02:57 am
content: maybe an order number?
Does anyone know what type of optical sensor this is? - Page 1
Forum section: electronics / projects

author: daisizhou
author_rank: Super Contributor
timestamp: September 29, 2025, 12:16:33 am
content: This is a circuit board that was disassembled many years ago.It came from an ophthalmic examination instrument, probably from Zeiss or a similar ophthalmic medical diagnostic instrument manufacturer.I want to know what type of sensor U4 is. I don't see any standard model.The PCB has the standard "HUMPHREY SYSTEMS" markIf anyone knows please tell me, thanks

author: amyk
author_rank: Super Contributor
timestamp: September 29, 2025, 12:56:42 am
content: Probably a quadrant photodiode.

author: TimFox
author_rank: Super Contributor
timestamp: September 29, 2025, 01:14:00 am
content: Quadrant photodiodes allow tracking motion or positioning in two dimensions.
Does anyone know who makes this? - Page 1
Forum section: electronics / projects

author: echtogammut
author_rank: Newbie
timestamp: August 09, 2013, 03:32:19 am
content: I am finishing up work on a project that is about to go to production. I hit a bit of a snag in finding the perfect box. I found another company that is making a box that meets my exact specs by I can't figure out where they are sourcing it (China obviously). It looks so generic, that I am guessing some company has this. It is a two part box 2.5x2.5x1.75 (total dimensions). The bottom section holds a 4AA battery compartment, which is crucial for my project. It is made out of fire resistant ABS. I am a few months out from production so I would rather not have to go full custom, but Evatron, Serpac, Boxedenclosures, Pactec and other that I have catalogs from don't have a similar size box with 4AA attachment (this being the key feature). Attached are some images, any ideas would be appreciated, I am having a contact in China ask around, but I would prefer to go through known distributors as this will initially be a low volume run.Thanks for any help, I am sure there are a lot guys posting these kinds of questions, but I can't believe such an obvious generic box is so hard to track down. Love this forum, I wish I knew about it years ago.
Does anyone make an LM337 / negative LM1117 in a SOT23 or smaller package? - Page 1
Forum section: electronics / projects

author: tom66
author_rank: Super Contributor
timestamp: October 01, 2013, 08:16:45 pm
content: The smallest package I can find an LM337 in is a SOT223/DPAK. Does anyone make one smaller at a low cost? Or an LM1117-type but negative? Currently I am using a PNP+resistor+zener but it is not well regulated under changing load, as expected.

author: edavid
author_rank: Super Contributor
timestamp: October 01, 2013, 08:26:32 pm
content: How about LM337LM (SO8)? Is that small enough?

author: AndyC_772
author_rank: Super Contributor
timestamp: October 01, 2013, 08:32:07 pm
content: This any good?http://www.maximintegrated.com/datasheet/index.mvp/id/2333

author: Andreas
author_rank: Super Contributor
timestamp: October 03, 2013, 07:46:22 am
content: LT1964-SD or LT1964-BYP if -20V input are sufficient.With best regardsAndreas
does anyone make off the shelf high voltage battery packs.  - Page 1
Forum section: electronics / projects

author: qwaarjet
author_rank: Regular Contributor
timestamp: January 30, 2021, 04:13:20 am
content: Anyone know of supplier who makes "off the shelf" ie non custom ~300V (20+Ah) battery pack with integrated charge control and cell balancing? I'm pretty comfortable with standard(and non standard) industrial power systems but I've never built a battery system over 48V, and I want to minimize the hackyness.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: January 30, 2021, 04:48:01 am
content: Most EV hybrids, give or take age/model (point being basically, NiMH vs. Li Ion), are in that range... take your pick?Don't know which ones have management internal, but there's a module for that somewhere, anyway. Probably someone's hacked them, figured out the protocols so they're usable for general purposes? Something to look into.Tim

author: NiHaoMike
author_rank: Super Contributor
timestamp: January 30, 2021, 05:05:22 am
content: Some home energy storage batteries operate at those voltages.https://www.solarelectricsupply.com/lg-chem-resu7h-400v-high-voltage-home-ess-energy-storage-battery-system

author: qwaarjet
author_rank: Regular Contributor
timestamp: January 30, 2021, 05:14:17 am
content: yea I was thinking some kind solar system (Powerwall or similar) might be the way to go bust most don't break out the DC bus. using a used EV also defeats the purpose of avoiding hackyness. Want something with warranty.
Does anyone recognise this CAN to USB converter board? - Page 1
Forum section: electronics / projects

author: e100
author_rank: Frequent Contributor
timestamp: January 11, 2021, 02:42:45 pm
content: I ordered a CAN to USB converter from a seller on Aliexpress and received thisThe marking says gd32e103 which appears to be an Arm Cortex M4.It doesn't work properly with the suggested Windows application called Microbus (cannot set baud rate) so there's something not right.This is the board I was supposed to receive.
Does anyone recognise this connector? - Page 1
Forum section: electronics / projects

author: philpem
author_rank: Frequent Contributor
timestamp: October 07, 2014, 12:22:33 am
content: Hi all,I've got a radio receiver (well it was a transceiver, but the transmit circuit is as dead as a dodo) on my bench which has, shall we say, seen better days. It's got data functionality built in, but only for a 1200 Baud system which was obsoleted in the mid-90s (not Mobitex, something else). I'd like to have a crack at improving it by adding a modern DSP microcontroller and teaching it some new modulation schemesThe sticking point are these connectors -- they appear to be 0.1in (2.54mm) pitch, but they're bottom-entry: there's a hole routed in the bottom of the PCB, and the pins (square pins, but fairly large ones) push up through the bottom of these connectors from the main board. Ideally I need to get some of these connectors as I'd rather not modify the main board (I have more of these radios and my want to modify them - a drop-in upgrade would be very nice!)Can anyone identify these connectors or -- even better -- point me to a supplier of them?I've trawled the Farnell catalogue but haven't managed to find anything quite like these...Apparently the radio was built by a company in New Zealand, if that helps for narrowing this down. I've got the service manual, but it doesn't list manufacturer part numbers, only the radio manufacturer's spares numberThanks,Phil.

author: David_AVD
author_rank: Super Contributor
timestamp: October 07, 2014, 02:12:08 am
content: Looks somewhat like the Molex ones I used on a retrofit module years ago. The 3-way 0.156" one was part number 0009484039.Maybe you can look that up and find the 0.1" ones from there?

author: calexanian
author_rank: Super Contributor
timestamp: October 07, 2014, 03:29:50 am
content: Also try Panduit/Pancon Mascon series.

author: philpem
author_rank: Frequent Contributor
timestamp: October 07, 2014, 07:10:42 am
content: Quote from: calexanian on October 07, 2014, 03:29:50 amSadly not -- the MAS-CON connectors are wire-to-board, while these are board-to-board.Quote from: David_AVD on October 07, 2014, 02:12:08 amNice one! I've just looked that one up on the Molex website (they call it a KK 396) and found the equivalent 0.1" series (KK 254). There's a bottom-entry variant which matches the connectors in the radio:http://www.molex.com/pdm_docs/sd/022142164_sd.pdf... but sadly the UK distributors (RS) only carry the smaller pin sizes. Mouser have everything up to 12 pins, so I might end up putting an order in with them. Hopefully they'll stack end-to-end for the longer sizes and can be cut down for the shorter non-stock onesThanks!- Phil.
Does anyone recognize these connectors? - Page 1
Forum section: electronics / projects

author: Jester
author_rank: Frequent Contributor
timestamp: February 12, 2018, 11:27:59 am
content: These are wire to board connectors used on those (really old now) Heathkit experimenters. It looks like it might be a Molex part?

author: Skashkash
author_rank: Regular Contributor
timestamp: February 12, 2018, 12:52:44 pm
content: Is that a connector or a breadboard contact block?https://www.elexp.com/ProductDetails.aspx?item_no=03TB-IVR

author: Jester
author_rank: Frequent Contributor
timestamp: February 18, 2018, 02:10:35 am
content: Yes it is.Have you ever ordered from the vendor in your link?Thanks

author: Skashkash
author_rank: Regular Contributor
timestamp: February 28, 2018, 01:54:17 am
content: No, never ordered from them.Just found the site after a bit of googling.They just had the best picture.

author: Nusa
author_rank: Super Contributor
timestamp: February 28, 2018, 03:30:07 am
content: I made an $80 order from elexp about 5 years ago. Sales staff were competent. The only glitch in the order was that they were out of the wire color I'd asked for (I substituted another color), which was cleanly handled before shipping. Their web presence used to be pretty raw. What I see now is much improved over what it was.Shipping charges may be killer if your order is small, however.
Does anyone want a schematic-to-Verilog converter? - Page 1
Forum section: electronics / projects

author: rea5245
author_rank: Frequent Contributor
timestamp: January 19, 2023, 10:48:09 pm
content: I've written a Python program to convert KiCad schematics to Verilog code. I did it because I'm designing a homebrew TTL CPU and I wanted a way to simulate it before physically building it.(Before you get too excited: it still requires you to write a lot of your own Verilog. It creates empty modules for all the components in the schematic, and wires them all up for you. But you still need to write the Verilog for each component.)I'm wondering if it's worth potentially several days of effort to get it in shape to be released as a KiCad plug-in. I realize this is a very niche application with very limited appeal. Is there conceivably any sort of substantial demand for something like this?

author: RoGeorge
author_rank: Super Contributor
timestamp: January 19, 2023, 11:21:47 pm
content: It might be of use, probably not very often. That is why Xilinx removed their schematic editor long time ago.However, Altera's Quartus (now bought by Intel) still has schematic input and a TTL library to just drag and drop chips into their graphic editor as if they were TTL ICs. Has simulation, too. If I were to simulate many TTL chips, most probably I would have done that using Quartus.This doesn't mean you should abandon your work. If it's not too complicated, yes, go ahead and turn that into a plugin.

author: BrianHG
author_rank: Super Contributor
timestamp: January 19, 2023, 11:54:14 pm
content: Quote from: RoGeorge on January 19, 2023, 11:21:47 pmQuartus also can generate a Verilog or VHDL source from your schematic which you can then compile on any other FPGA vendor's EDA suite.

author: rea5245
author_rank: Frequent Contributor
timestamp: February 01, 2023, 06:21:46 pm
content: Well, I did it: a KiCad plugin to convert schematics to Verilog. You can find it athttps://github.com/galacticstudios/KiCadVerilog
Does brand matter at film capacitors  - Page 1
Forum section: electronics / projects

author: Miyuki
author_rank: Frequent Contributor
timestamp: June 15, 2018, 09:02:42 am
content: Hi folks,Does brand matter at film capacitors ? And if, how much ?Especially when used at high ripple current or is it similar story to electrolytic ?

author: Kleinstein
author_rank: Super Contributor
timestamp: June 15, 2018, 09:50:17 am
content: It depends on the required properties of the film cap.The main advantage of some big brands can be more trust in there specs and less chance to get a really poor series which might need a recall or such. However the type of film capacitor can make a big difference. So the first thing is to get the right type (dielectric and construction (metalized or metal foil)) - the brand might matter when you need extreme properties, like very low loss. I would not expect the differences to be as large as with electrolytic caps. The construction is usually easier and also small companies can make good film caps - there is way less magic included and also less aging.With high ripple current, there usually is also a chance for dielectric losses to become significant, not just the ripple current.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: June 15, 2018, 10:23:41 am
content: Well... how cheap do you want to go?All the usual brands, at the big distributors, are good. Regarding current, they are what they are.Obviously, if you're shopping on eBay or Ali, you're on your own.If you need current handling, then if they don't specify in the datasheet, it's probably no good.One exception, Orange Drops (Vishay Sprague 715P) are surprisingly good at current, for not being specified. It's unfortunate that they have steel leads.X2 caps are mostly terrible, for example Vishay BC ones (which part number / family, I forget) are good for maybe 50mA in typical values.Snubber caps often are rated for peak current but not RMS. For these, you can estimate RMS current as: Irms = dV/dt(pk) * C / 20, or Ipk / 20. This is a crude assumption and real parts vary higher or lower than this. Example, CDE 935s are rated for a lot of peak but little RMS capacity, particularly at high frequencies.The loss of current capacity, at high frequencies, can be considerable. It's a skin effect phenomenon. Lots of small pieces is better than one large piece. At some point, ceramic also takes over from film caps, which stinks for commodity parts because C0G chip caps are so expensive (but then, so are industrial transmitter caps -- you're stuck on that, unfortunately).Tim

author: Miyuki
author_rank: Frequent Contributor
timestamp: June 15, 2018, 10:45:46 am
content: Just cheapest one from local distributor, no need to risk eBay/AliThey will be paralleled with electrolytic but much closer to semiconductors as they have no so big heat life issue when proper voltage is chosen
Does exist alternative for YAMAR PLC chips for DC lines?  - Page 1
Forum section: electronics / projects

author: Miyuki
author_rank: Frequent Contributor
timestamp: April 20, 2021, 07:58:40 am
content: Hi.Just wonder. Is there any alternative for YAMARs chips when I want UART or CAN ower DC line? It looks to me like the only manufacturer of this solution. Is it really so low demand market?

author: spostma
author_rank: Regular Contributor
timestamp: May 18, 2021, 08:32:10 pm
content: a bit late reply, but have a look to- Texas Instruments THVD8000 RS-485 Transceiver with OOK Modulation for Power Line Communication up to 1mbps- M-Bus interface chips like XI'AN Supermicro SE722, gatemode MC8721C, Holtek HT45B0003 / HT45B0005- EDN article "Simple Circuit Communicates Over Low-Voltage Power Lines" by Julia Truchsess- article "Circuit Implementation of OOK Modulation for Low-Speed Power Line Communication Using X10 Standard" by Chia-Hung WANG, Chia-Yu CHEN, and Tai-Ping SUNI have not checked the status of these chips, but at least the THVD8000 is brand new.

author: Miyuki
author_rank: Frequent Contributor
timestamp: May 19, 2021, 05:47:13 am
content: Thanks, that THVD8000 looks like a nice solution, integrated without plenty of external components and for a reasonable price.And have documentation and is available
Does exist any free software tool to simulate digital controlled PWM converter? - Page 1
Forum section: electronics / projects

author: Miyuki
author_rank: Frequent Contributor
timestamp: April 23, 2022, 06:18:33 pm
content: Hi folks.I have a question. Does exist some, preferably free, tool to simulate the behavior of a digital converter?Without needing to manually convert everything to some crazy math equations from the control algorithm.use case example: 2 and 3 phase interleaved boost converter with disabling some phases at light load. I would like to tune the control algorithm in some simulation before Ill try it on a physical device.

author: Someone
author_rank: Super Contributor
timestamp: April 23, 2022, 11:40:09 pm
content: Quote from: Miyuki on April 23, 2022, 06:18:33 pmFree? not that I'm aware of. There are paid tools that let you co-simulate digital/code and analog alongside each other with entry in their original forms, but if you go free then you have to do the conversion from one domain to the other by hand.

author: NiHaoMike
author_rank: Super Contributor
timestamp: April 24, 2022, 02:27:30 am
content: Matlab is often used for that and Octave or Scilab is a free alternative to Matlab.

author: Miyuki
author_rank: Frequent Contributor
timestamp: April 24, 2022, 11:10:22 am
content: As I looked at it I might end up at MatlabIt looks like there is a clear reason why people use itIt has everything I wantI'll try it in trial and maybe invest in some home version later
Does exist NMEA 2000/J1939 message for central/emergency shutdown? - Page 1
Forum section: electronics / projects

author: Miyuki
author_rank: Frequent Contributor
timestamp: January 18, 2023, 11:26:04 am
content: Hi folks,I want to ask you, more experienced with these protocols. Does exist some standardized NMEA 2000/J1939 message for central/emergency shutdown?I'm working on some inverters with a CAN connection. And want to implement an emergency shutdown, either user-triggered or when something bad is detected by one of the devices.I would expect there are some standardized messages for such cases, but cannot find any info about it.
Does exist proportional 0-10V SSR/SCR control circuit ? - Page 1
Forum section: electronics / projects

author: Miyuki
author_rank: Frequent Contributor
timestamp: November 04, 2022, 08:29:37 pm
content: Hi folks.I wonder if exist some of the shelf firing circuit with proportional input.I see someChinese proportional SSR in those square caseswith screw terminals and with little to no datasheets. I'm curious what is in them.And then some big expensive industry onesIs there some dedicated chip for it or is it just MCU based today?

author: NiHaoMike
author_rank: Super Contributor
timestamp: November 05, 2022, 01:02:50 am
content: The simplest would be a light dimmer circuit with a LDR illuminated by a LED.

author: themadhippy
author_rank: Super Contributor
timestamp: November 05, 2022, 02:07:29 am
content: Quotecrydom certainly used toQuoteah,they might be outside your price range
Does it make any sense to put power switching/small motor PWM on a second PCB? - Page 1
Forum section: electronics / projects

author: newto
author_rank: Regular Contributor
timestamp: September 01, 2020, 07:52:13 pm
content: With how cheap 100x100mm 2 and 4 layer boards are from JLC, would it make sense to separate all the voltage switching/motor pwm/battery charging/BMS on a second PCB?My project is already going to have two PCBs, one with some sensitive analog components and the MCU, and the other PCB with a 2s2p battery charging and management circuit, and I'm trying to figure out if it would help or hurt noise to put some of the switching based components onto the battery PCB instead of the main board.Specifically:6V pump motor PWM control+3.3V buck-3.3V charge pump+5V buck24-30V boost95% of the board will be running on 3.3V, with one set of sensors needing 5V, and another needing 24-30V (both very low current). Intuitively, it feels like the 6V pump PWM can be on the other board, since none of the main components will be running on 6V, but would putting the other power stuff on the second board screw with return paths and make things noisier than just having them sort of close on the same small board?

author: thm_w
author_rank: Super Contributor
timestamp: September 01, 2020, 09:29:56 pm
content: Its all trade-offs. You can have the same circuitry on one board and just put it very far apart, but then that means more horizontal space taken up.If currents are very high it may make sense to have a power board that uses thicker copper (2oz).Then you get into the connectors and wiring between the two boards.What kind of currents are we talking about?If this is a hobby project I would focus more on what makes it easier to design and build for you. Off the shelf 2s BMS PCBs are commonly available.

author: newto
author_rank: Regular Contributor
timestamp: September 02, 2020, 02:22:55 pm
content: Quote from: thm_w on September 01, 2020, 09:29:56 pmFairly low, the pump is <500mA if it ran at full speed and pressure (so likely closer to 200mA in use), the 24-30V sensor is a few mA, and the 5V sensor is <100mA.For the BMS, it's half as a practice/experience type of thing, and half not wanting to deal with aliexpress parts. I'm sure they're perfectly safe, but the constant appearing and disappearing dealers and designs makes me not want to deal with it, and shipping these days is an absolute mess.
Does it make sense to give homebrew SBC features like Ethernet, or USB OTG? - Page 1
Forum section: electronics / projects

author: technix
author_rank: Super Contributor
timestamp: March 09, 2017, 12:15:44 am
content: I have a few WCH CH395 Ethernet controller and CH375 USB OTG controller, both capable of operating on the FSB of a homebrew SBC. Does it make sense to put those features onto a homebrew SBC though? Something based on 68HC000 or 80C88 or Z84C00.

author: Nusa
author_rank: Super Contributor
timestamp: March 09, 2017, 12:39:15 am
content: I guess it depends on what you plan to DO with the SBC. If you want to support a modern keyboard, the USB controller may be useful. If you want it to talk to the world, then the Ethernet controller makes sense. Back in the day it would have been a serial port to dial-up modems (my first one was a 300 baud acoustic...you stuck the phone handset in its cradle).

author: singapol
author_rank: Frequent Contributor
timestamp: March 09, 2017, 01:45:59 am
content: I assume you are chinese and a practical one.Why reinvent the wheel when there are ready solutions which are cheaper and efficient. To be creative is to make use of things created by geniuses. Apple did not invent the technologies but simply put them to good use to make products that people want. See the difference? If you research all the great inventions did the original creator became super rich? I know it's superficial and materialistic but without money can people like boss of virgin airlines venture into space? Same for Mr.Ma of Alibaba. At most for their contributions to mankind the geniuses got a Nobel prize of US$2 million..enough just to get an apartment in Hong Kong? Oh and please don't tell me me you want to learn and don't mind blowing things up.

author: Ian.M
author_rank: Super Contributor
timestamp: March 09, 2017, 02:50:07 am
content: In general, I'd say no, not for the 8 bit systems, and I'm including the 8/16 bit 80C88 in that category. I've had DOS PCs on Ethernet and it wasn't much fun.I don't think I've ever had an 8088 networked,(I tell a lie - I once had the joys of installing Novell Netware on an IBM XT for an assignment)but I had a 286 hooked to my LAN for a while. There might be an exception to support Telnet, so you can run the SBC headless from a remote terminal and TFTP for loading/saving from memory. I don't see the benefits of host USB at all - its just more clutter on your bench to have a separate keyboard for the SBC, and there are better solutions for mass storage e.g. CF cards. Most anything else is going to run into driver issues to do anything useful.The 68HC000 is a different matter. With a 32/16 bit processor and a 16MB address map, ucLinux is possible, and once you have a fully featured OS on there, USB and Ethernet make a lot more sense.Your old 68HC000 topic for reference:https://www.eevblog.com/forum/chat/i-pulled-the-plug-and-bought-a-mc68hc000-help/This 68008 project is worth a look for inspiration - though you have to contend with a 16 bit bus so a lot more wiring.http://www.bigmessowires.com/68-katy/
does it make sense to protect electrolytic coupling capacitor from ESD? - Page 1
Forum section: electronics / projects

author: SArepairman
author_rank: Frequent Contributor
timestamp: October 16, 2014, 11:57:27 pm
content: I built a little preamplifier, which features a AC coupled 50 ohm input.I have a low voltage GDT sitting around, does it make sense to put ESD protection on a electrolytic coupling capacitor (polymer 16v)?

author: moffy
author_rank: Super Contributor
timestamp: October 17, 2014, 02:13:51 am
content: No. But 50ohm with an electrolytic coupling cap sounds a little strange. Electro's don't make good coupling caps in audio because they have a voltage dependent non linearity i.e. they introduce distortion. Why 50ohm?! sounds like something RF not audio.

author: Richard Crowley
author_rank: Super Contributor
timestamp: October 17, 2014, 02:31:30 am
content: Is this an audio circuit? An RF circuit? What is the nominal signal voltage here?It really isn't possible to provide a useful response without knowing anything about the situation.Is this an application where you expect large fault currents? Like an antenna up in the air, or a long overhead transmission line?What does "low-voltage" GDT mean? If it is > 16V then it provides no protection to the capacitor.Furthermore, it doesn't make much sense to use a more expensive component to "protect" an inexpensive commodity component.Like using a $20 circuit breaker to "protect" a 20-cent fuse.Depending on the nominal signal voltage (not revealed here), it typically makes more sense to use diodes to protect the output.There are many different protection circuits and schemes depending on details of the application not in evidence here.

author: f5r5e5d
author_rank: Frequent Contributor
timestamp: October 17, 2014, 02:32:48 am
content: ESD is seldom enough charge to put any appreciable V on larger uF to mF coupling capsbut the cap may be a fine short at ESD edge rates to your circuit's input devices that may want protection

author: Conrad Hoffman
author_rank: Super Contributor
timestamp: October 17, 2014, 03:54:52 pm
content: I assume you've got the typical preamp output with some opamp or discrete circuit, a 50 ohm stabilization resistor and an AC coupling cap. The 50 ohms here has nothing to do with impedance matching or RF concerns, it just insures stable operation with cable capacitance. I see values of anywhere between 10 and 600 ohms, though 50 and 100 seem most common. In the history of audio I doubt a cap has ever been damaged by an ESD event short of a lightening strike. I'd never add protection. As for the coupling cap, though film is preferred, as long as the electrolytic is large enough, and remember it's likely in series with a similar cap in the power amp, you won't get distortion. The usual rule is 10X the value for the desired -3dB point, effectively a couple Hz.
Does my chips look genuine? Round 2: NOS and second-hand precision references - Page 1
Forum section: electronics / projects

author: technix
author_rank: Super Contributor
timestamp: November 19, 2015, 05:37:20 pm
content: Chips involved:REF03 (Analog Devices), supposedly NOS. probably second hand? Checked and they seemed to work (but I don't have good enough a multimeter to check)LM399 (National Semiconductor), second hand.ADR02B (Analog Devices), second hand. Checked and they seemed to work (but I don't have good enough a multimeter to check)p.s. I know I mounted one of my ADR02B the wrong way. Don't complain.

author: Andreas
author_rank: Super Contributor
timestamp: November 19, 2015, 06:53:27 pm
content: Hello,At least the LM399 upper right looks very similar to the LM399 that I have.With best regardsAndreas
Does my FM scanner circuit look reasonable? - Page 1
Forum section: electronics / projects

author: cap11235
author_rank: Newbie
timestamp: April 10, 2014, 04:21:01 am
content: I've planned out an FM scanner that I'm going to build, but I'd like to have someone eyeball it first to make sure I'm not going to waste a lot of time on something silly. I'm more of a digital fellow, and analog is relatively new to me.Anyway, how I intend this circuit to work is I have a voltage from a DAC to signify the frequency to tune to. This goes to a LTC6905 acting as a VCO (I copied this out of the docs for it), which then goes to a JFET mixer. The other input to the mixer is from the antenna, followed by a high pass filter and aJFET amp. Then, I filter to get the audio component, and then I branch that off.One side goes to a simple inverting amplifier with a push-pull output then headphone jack, and the other goes to an active rectifier, which then gets smoothed with a cap, which goes to an ADC for the digital bits to be a measure of signal amplitude.Does this seem reasonable? I'm fairly confident in the opamp bits, and the LTC6905 (since it is straight from the app notes), but JFET's seem rather unpredictable to me.Thank you for your help.
Does output of current mode boost converter is a constant current? - Page 1
Forum section: electronics / projects

author: Sai teja
author_rank: Regular Contributor
timestamp: March 15, 2018, 05:38:58 am
content: Hello, I want to use LMR62014 for my boost application. My specifications are as follows.vin: 6V t0 8.4Vvout : 8.4 VIload(max) : 0.8 ampI used TI's webench tool to freeze my schematic.I would like to know whether the output from the LMR62014 is constant current (0.8A) or does it provide the current as per load requirement.Please explain what is current mode boost converter as well?Datasheet of the IC :http://www.ti.com/lit/ds/symlink/lmr62014.pdf

author: jismal
author_rank: Contributor
timestamp: March 15, 2018, 06:03:17 am
content: Speaking in a nut shell, A constant current source tend to increase the voltage to make current constant. And similarly a constant voltage source will increase the current to make voltage constant. For a given load.In your case it will it will provide current as load required.that means it will not be giving out .8Amps at 1kohm load. it will be only giving 8.4mA instead.

author: Sai teja
author_rank: Regular Contributor
timestamp: March 15, 2018, 10:22:48 am
content: My input to IC varies from 6 to 8.4VMy output requirement is 8 V.As this is boost IC, what happens to output voltage when my input voltage is between 8 to 8.4 V

author: slugrustle
author_rank: Frequent Contributor
timestamp: March 15, 2018, 02:16:57 pm
content: It depends on the forward voltage of D1 in the connection diagram on page 2 of the datasheet. If Vin is higher than the regulating voltage of the converter, and Vin - Vout is higher than D1's forward voltage at the load current, you will get Vin - D1_forward_voltage on the output.With boost converters, there is always a path from Vin through the inductor and boost diode to the output.
Does PLCC count as a through hole package? (With sockets in mind) - Page 1
Forum section: electronics / projects

author: technix
author_rank: Super Contributor
timestamp: October 29, 2018, 05:28:59 pm
content: While the chip by itself says no - PLCC is a surface mount package and when directly mounted on a PCB it is intended to be soldered mounted on the surface, what about when it is socketed? PLCC is likely the only surface mount chip package type that has cheap sockets available (as in dime a dozen sockets flooding Shenzhen market) and a lot of boards do socket their PLCCs, and one of the socket options is through-hole. So, does PLCC count as through hole package, especially if socketed?

author: DaJMasta
author_rank: Super Contributor
timestamp: October 29, 2018, 05:34:34 pm
content: They make sockets in both through hole and surface mount varieties, so I suppose it's both until you decide on a way to mount it.

author: David Hess
author_rank: Super Contributor
timestamp: October 31, 2018, 07:13:05 pm
content: It still counts as surface mount. I which more parts were available in the PLCC package for ease of prototyping.

author: bson
author_rank: Unknown
timestamp: October 31, 2018, 09:01:50 pm
content: Depends on who is counting, doesn't it?For example, for assembly since it can't be reflowed a TH socket would not be an SMD device, as it would incur additional work and cost to populate.

author: David Hess
author_rank: Super Contributor
timestamp: October 31, 2018, 11:54:06 pm
content: Quote from: bson on October 31, 2018, 09:01:50 pmIf I go to Mouser or Digi-Key and look for PLCC parts, they are only going to be found under surface mount.

author: bson
author_rank: Unknown
timestamp: November 01, 2018, 12:07:21 am
content: That makes perfect sense.

author: technix
author_rank: Super Contributor
timestamp: November 01, 2018, 01:40:26 am
content: Quote from: bson on October 31, 2018, 09:01:50 pmMaybe not if the board is otherwise THT-only.Quote from: David Hess on October 31, 2018, 11:54:06 pmThat is those chips by themselves. What about when socketed?

author: DaJMasta
author_rank: Super Contributor
timestamp: November 01, 2018, 01:44:39 am
content: Is your socket through hole or surface mount? Both are available. If you get a through hole socket, it's a through hole part as far as labor and design considerations go, if you get a surface mount socket it's a surface mount part...... seems straight forward to me.
does PNP or NPN Make more sense in this welding circuit? - Page 1
Forum section: electronics / projects

author: coppercone2
author_rank: Super Contributor
timestamp: September 24, 2024, 03:06:43 am
content: 2 replies on another forum say its a 04, the schematic someone made says its 06.I am inclined to believe the schematic, but my memory of the event is shot. Basically I fixed a welding machine, but wanted to replace a few more parts near the damaged one, just incase. I replaced everything I thought was possibly related, then there was a explosion near this transistor. I am almost sure its supposed to be a 2n3906, and that a moron and a parrot lead me in the wrong direction, but I just can't be sure if there perhaps is a different problem.This is a diagram from a welding forum someone drewThe transistor in question is Q3, which is a 06 in diagramIs there any clues to tell me if a NPN could some how make sense in that point of the circuit? Q3 is on top left, near the opto. R2 is the resistor that managed to explode, and it took out a IGBT!

author: T3sl4co1l
author_rank: Super Contributor
timestamp: September 24, 2024, 11:19:15 am
content: Well, PNP would be upside-down. NPN would conflict with the logic output on its collector, but I suppose one could abuse a CD4000 at 15V, it's only sourcing 10, 20mA or so; a 3904 with ~1k base resistors can easily overpower that.Without knowing what IFB_Buck is, or general operation of the thing, I don't know if it might make more sense with a PNP right-side-up.Despite the output overdriving, it doesn't seem like something that would explode.Tim

author: coppercone2
author_rank: Super Contributor
timestamp: September 24, 2024, 08:13:46 pm
content: If there is a conflict that is good enough reason to assume that it is a 06. Its easy to mis-read, you need to scrape off conformal coating and use magnifier, easy to turn the 9 into a 4ish thing. I think I recall there being a incorrect amount of PNP from the list I made in excel that got deletedI think the schematic maker just flipped the part to make it look neater?It is some how connected to a supply that turns 800V into 30V I think. but yeah exploding a 1.5k ohm resistor is next level (crater in pcb)