hybridfree/eevblog-posts huggingface dataset:
Looking for a distributor/seller of NiZn/MnZn toroids - Page 1
Forum section: electronics / projects

author: TimNJ
author_rank: Super Contributor
timestamp: January 23, 2019, 06:47:24 pm
content: Hi all,Does anyone know of a distributor of those ubiquitous green-colored MnZn or NiZn ferrite cores that are found in just about every switchmode power supply in existence?At work, we have a few Chinese sources including China DMEGC and Tianming ...but for anyone playing at home, most of these companies won't talk to you unless you're buying 1Kpcs+.Anyone know where to get these? Aliexpress has a scattered assortment, and without much info on manufacturer.Really just curious more than anything.Thanks,Tim

author: ebclr
author_rank: Super Contributor
timestamp: January 23, 2019, 06:58:10 pm
content: https://lcsc.com/products/Power-Inductors_544.html

author: strawberry
author_rank: Super Contributor
timestamp: January 23, 2019, 07:16:02 pm
content: https://eu.mouser.com/Passive-Components/EMI-Filters-EMI-Suppression/Ferrites/Ferrite-Toroids-Ferrite-Rings/_/N-bw7t9/http://www.cosmoferrites.com/product-size.aspx?id=8

author: Yansi
author_rank: Super Contributor
timestamp: January 23, 2019, 07:18:42 pm
content: SEMIC.cz (they have large selection of Cosmo Ferrites (and others') products in stock).

author: TimNJ
author_rank: Super Contributor
timestamp: January 23, 2019, 09:08:31 pm
content: Thanks all.I kind of forgot that Fair-Rite makes lots of NiZn and MnZn cores. They just use a parylene coating and not the colored epoxy/plastic you typically see.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: January 24, 2019, 12:28:22 am
content: If you're not picky about them being green, you can get the same materials, yes.Specifically, being common mode chokes, those should be the highest permeability, 10-15k mu_r, MnZn.Fair-Rite, EPCOS/TDK, Laird, etc. are available from mainline distributors, and others from magnetics distributors likehttp://elnamagnetics.com/or if you're desperate for a pricey web order, Amidonhttp://www.amidoncorp.com/Tim
Looking for a documentation tool for pinout/wires/connectors. - Page 1
Forum section: electronics / projects

author: Odd
author_rank: Regular Contributor
timestamp: December 12, 2023, 10:11:30 am
content: I am aware of python "pinout" on github.Its manual coordinate requirement is suboptimal for projects that are modified on a regular basis.Are there similar projects that can easily be used to document builds?- I am looking for multiplatform tools.

author: eosti
author_rank: Newbie
timestamp: December 13, 2023, 03:28:24 pm
content: For wiring and connectors, you might want to take a look at WireViz:https://github.com/wireviz/WireViz. Configuration is entirely done in YAML, and then it generates a nice visualization for you. Development has stagnated a bit over the last few years, but there's been talk of additional features in the pipeline.It looks like boardgen (https://github.com/kuba2k2/boardgen) is similar to the pinout package that you mentioned, but might still require manual coordinate setting. I haven't used this particular tool though, perhaps it might work better for your needs.
Looking for a durable 0.025" socket... - Page 1
Forum section: electronics / projects

author: alank2
author_rank: Super Contributor
timestamp: May 13, 2017, 02:33:27 am
content: I can't help but think some of them are tougher than others. I don't know much about them, but the idea of a tube that keeps the pin (either 0.025" square or a machine round one) from damaging the wiper that presses against it when inserted seems like a good idea. I guess what I am asking for is a heavy duty socket that will put up with a lot of use and still maintain a solid connection. I found this on Digikey and it has what looks like a metal spring built in as the part that presses against the pin for a solid connection. I would think this design would be pretty robust. Any better ones or types?https://www.digikey.com/product-detail/en/amphenol-fci/75231-013LF/609-4536-1-ND/2665625

author: tautech
author_rank: Super Contributor
timestamp: May 13, 2017, 03:06:01 am
content: Quote from: alank2 on May 13, 2017, 02:33:27 amThey do look a little more robust than those I use and IIRC price seems about the same.Shrink sleeve over and you'll be good to go.

author: alank2
author_rank: Super Contributor
timestamp: May 13, 2017, 03:36:00 pm
content: That is what I was thinking - they look pretty tough! I'll order some and give them a try.
Looking for a fast possibility to compare dcdc converter IC - Page 1
Forum section: electronics / projects

author: Bartakus
author_rank: Newbie
timestamp: October 20, 2014, 12:06:47 pm
content: Hi!Does someone know a fast way to compare across manufacturers dcdc converters IC?Thanks!

author: Edwarn
author_rank: Newbie
timestamp: November 19, 2014, 04:39:44 pm
content: have a look atwww.dcdcselector.comIts a new ic Search Engine.You can also use farnell or pololu.com, but i think this tool is the best choice for you.have a nice time!Edwarn
looking for a footprint for a pcb - Page 1
Forum section: electronics / projects

author: p.larner
author_rank: Frequent Contributor
timestamp: December 31, 2023, 09:14:38 pm
content: I am putting together a homebrew atu,i an using a couple of ceramic wafer switches for hi/loz and meter range switching etc,they are 112 pole i think,see pic,i am wanting to etch a pcb that can work as a sort of breakout board,i need something printable for toner transfer,its dia is 31mm and distance between mounting holes is about 26mm,its from an old collins tradio part amplifier,has anyone any idea if its a standard switch and where i can find a footprint to etch onto a pcb?.Sorry about the poor pic but you should get the idea

author: themadhippy
author_rank: Super Contributor
timestamp: December 31, 2023, 09:26:38 pm
content: QuoteThats a big switch or do you mean 1 pole 12 way?

author: p.larner
author_rank: Frequent Contributor
timestamp: December 31, 2023, 10:38:32 pm
content: its double sided,it is a pcb footprint i want to solder the switch to so its terminals marry up with copper pads that i can then incorperate into a pcb to connect everything with,i dont want a rats nest and wires putting stress on the wafer switch terminals,i dont know what it would be called too do a search on kikad fooitprints etc,hence my question.

author: Halcyon
author_rank: Unknown
timestamp: January 01, 2024, 01:15:20 am
content: Duplicate post.
Looking for a small and soft HDMI adapter / cable in silicone.... - Page 1
Forum section: electronics / projects

author: ziomario
author_rank: Contributor
timestamp: July 24, 2025, 07:36:08 pm
content: Hello to everyone.I'm trying to assemble my first DIY CyberDesk device or phone,I don't know,using only modular components,that I can attach and detach easily,like USB devices and HDMI screens. Actually I would like to connect the HDMI screen that you see on the left with the main board that you see on the right. The first one has one HDMI female port,that I have converted in one HDMI micro male connector. The main board has one HDMI micro female port. I need a short cable (of 5 max 6 cm),soft and flexible (silicone is the best) to attach the display to the main board. I think that different permutations are also acceptable,but not so much. I will discard every HDMI adapter that will protrude too far from the case.Very thanks.picture 1.pngThis is another permutation :picture 2.pngAgain another variant :picture 3.pngAgain another one :picture 4.png

author: ziomario
author_rank: Contributor
timestamp: July 26, 2025, 10:31:41 am
content: Anyone can suggest something ? Cables in silicone are the best.

author: shabaz
author_rank: Frequent Contributor
timestamp: July 26, 2025, 11:07:38 am
content: Its unlikely there are too many 5 cm commercial offerings, since not many people would find a use for that. HDMI connectors are usually used inter-equipment, not internally as you're doing, so they are of course longer normally.Maybe one of the hobby stores like Adafruit may have something.Or, Google for things like "flat flex HDMI" to see possible candidates which use small PCBs at each end, connected together with a length of FFC (flat flex cable) which can be swapped out for a shorter length one and folded over if its still too long.If that's not suitable, you could consider designing your own adapter in a similar way (or design it entirely out of flexible PCB material) but it seems a bit excessive.It might be easier to re-print the enclosure modified, to suit what you've got.

author: macboy
author_rank: Super Contributor
timestamp: July 26, 2025, 12:51:06 pm
content: You can get modular HDMI cables where you buy the two ends and use a flat flex of whatever length you need to connect them. You would be able to use a micro HDMI on one end and maybe a right angle HDMI on the other end. A shop local to me called pishop.ca carries these. Search them for "diy hdmi" and you will see what I mean. I'm sure you can get these at many other places too if you know what to search for.

author: mtwieg
author_rank: Frequent Contributor
timestamp: July 26, 2025, 12:53:42 pm
content: I don't think you'll find any off-the-shelf HDMI cable with such a short length. Such a thing hardly makes sense...Shortest I could find is this rasberry Pi cable which says it's 10cm:https://www.digikey.com/en/products/detail/raspberry-pi/SC0726/15298149It's not clear from your photos what gender you actually need for the ends of the cable.Quote from: shabaz on July 26, 2025, 11:07:38 amQuote from: macboy on July 26, 2025, 12:51:06 pmThis seems like a viable approach.
Looking for a HDMI driver board compatible with the HyperPixel 4 Square touch - Page 1
Forum section: electronics / projects

author: ziomario
author_rank: Contributor
timestamp: April 24, 2025, 12:29:25 pm
content: Hello to everyone.Some time ago I've bought this display :https://shop.pimoroni.com/products/hyperpixel-4-square?variant=30138251477075I want use it with FreeBSD. The problem is that the driver has been written for Linux and it will never work for FreeBSD. But I've thought. I have only a chance. To find a compatible HDMI driver board. I've googled a little bit and I found this web page :https://forum.core-electronics.com.au/t/driver-boards-for-ips-screens/12063at certain point,someone suggests that I can buy this adapter from Adafruit :https://core-electronics.com.au/tfp401-hdmi-dvi-decoder-to-40-pin-ttl-breakout-without-touch.htmlI asked to Pimoroni. The engineers suggest that looking at the configuration for Hyperpixel on Raspberry Pi is probably the best place to start. The DPI timings are the 'secret sauce' that makes this display work - the timings used for Hyperpixel Square can be found here:https://pinout.xyz/pinout/hyperpixelI've attached the ribbon pinouts layout pictures...I would like to know if it is compatible with my hyperpixel 4 square touch display. If it is not,can u suggest one that it is ? thanks.
looking for a kind of ISO7816 card with EEprom but without any smart chip - Page 1
Forum section: electronics / projects

author: legacy
author_rank: Super Contributor
timestamp: January 04, 2020, 05:46:02 pm
content: With ISO7816 we usually mean smartcards with EEprom interfaced by a "smart-chip" that adds a layer of security, and/or cryptography.I do not want any smart chip, I just want a EEprom (32Kbyte at least) in a ISO7816 shape. And I need to read and also write it, ideally via I2c or SPI. For sure I do not want any "contactless" RF interface.Any idea? I cannot find anything similar

author: up8051
author_rank: Frequent Contributor
timestamp: January 05, 2020, 06:22:12 pm
content: For example:ISO 7816 White AT24C64 Chip Smart IC Card with 64K EEPROM Memoryhttps://www.aliexpress.com/item/32811339130.html

author: legacy
author_rank: Super Contributor
timestamp: January 06, 2020, 02:20:32 pm
content: Thanks. I think the confusion in my mind is the word "Smart" used to describe these cards as "AT24C64 Smart Chip" because in my head I assumed "Smart" = "there is an MPU to interface the EEPROM" whereas these cards are just serial(1) EEPROM chip made in ISO7816 form factor, but I had several difficulties at finding the datasheet to have a confirm.(1) the protocol is a common i2c.

author: up8051
author_rank: Frequent Contributor
timestamp: January 06, 2020, 02:32:17 pm
content: AT24C64SChttp://www.greendich.com.tw/products/acg/AT24C32SC.pdf
Looking for a LiPo charging IC with 5V boost - Page 1
Forum section: electronics / projects

author: dingari
author_rank: Contributor
timestamp: September 14, 2016, 11:20:10 am
content: Hi, I'm designing a board, and I have the following requirements:USB chargedLiPo battery (approx 3-4.2V range)5V output voltageUp to 2A peak output currentSmall footprint (non-BGA)Up to this I've been using MCP73871 for charging and TPS61092 to boost the battery voltage to 5V, but I'm looking for a single-chip solution.I've looked through TI's site (specifically the BQ24 and BQ25 series), and didn't really find anything that suited this application. I don't need USB OTG boost.Then I found chips from Active-semi and Maxim on Mouser.comACT2813MAX8903The Active-semi one caught my eye since it's only $2, while the others are around $4-5.Has anyone tried these, or similar, and could help me out here?

author: Siwastaja
author_rank: Super Contributor
timestamp: September 14, 2016, 12:00:34 pm
content: Quote from: dingari on September 14, 2016, 11:20:10 amI can't understand why you'd want this? It can't work in any other sense than maybe safety testing for approval purposes? (Testing how spectacularly the battery goes off?)Edit: I understood what you are after: an integrated energy bank IC. A clearer description would have helped.

author: dingari
author_rank: Contributor
timestamp: September 14, 2016, 02:37:40 pm
content: Quote from: Siwastaja on September 14, 2016, 12:00:34 pmSorry if my description was not clear enough. Now I at least know that what I'm looking for has a name.
Looking for a LiPo charging IC with integrated LDO - Page 1
Forum section: electronics / projects

author: dingari
author_rank: Contributor
timestamp: October 10, 2016, 08:35:09 am
content: Hi, I'm currently working on a small device that runs off a single-cell LiPo battery. Currently I'm just using MCP73831 and a 3.3V LDO (two SOT23-5 packages).I'm looking to shrink my design further and look for a charging + LDO IC combo. Charge current needed is about 100-200mA, and the system draws no more than 20mA at 3.3V (usually much less). So far I've only foundBQ2512xfrom Texas Instruments that really fits my application. The I2C interface is a nice bonus for monitoring voltage and reducing external components etc.But what other options do I have? Are there ICs that are more suitable for this job?
Looking for a Lithium Buck Boost regulator with USB charging - Page 1
Forum section: electronics / projects

author: veryevil
author_rank: Unknown
timestamp: February 27, 2014, 01:27:47 pm
content: Hi, as the title suggests I'm looking for a single chip (preferable) that takes a single cell lithium battery and give out a fixed 3.3v output with a max current of 50mA. I would also like it to connect to USB and charge the battery as well as power the system.Do you know of any parts or you have you used one before? Am I optimistic in thinking I can get a single chip solution?ThanksStevenEDIT: Also efficiency (on battery) is key as the device sits for most of its life at about 100uA

author: 8086
author_rank: Super Contributor
timestamp: February 27, 2014, 01:34:38 pm
content: I've been looking for something similar recently and not had much luck. This is the closest to what you want, I think, but it's not a single chip:https://www.sparkfun.com/products/11231

author: treespicer
author_rank: Newbie
timestamp: February 27, 2014, 04:24:05 pm
content: Is two chips acceptable? Are you just looking for lowest footprint?

author: veryevil
author_rank: Unknown
timestamp: February 27, 2014, 04:46:53 pm
content: Yeah I guess it was optimistic to hope for a single chip solution. I also wasn't sure about how to have both the USB power and the battery power on.

author: b2theory
author_rank: Contributor
timestamp: February 27, 2014, 04:56:15 pm
content: Do you want to be able to charge and discharge our of the same USB Port?

author: treespicer
author_rank: Newbie
timestamp: February 27, 2014, 05:01:58 pm
content: The BQ2407x family from TI is a combined power-path/battery charger. This enables you to power the device and charge the battery at the same time. They have a nominal UVLO of 3.3V. Then just throw a small LDO or buck converter on the output.Edit: I just realized you said "buck boost". You could operate from battery to around 3.4V with an LDO or buck. Realistically, you'd only get about 15% more capacity after that point by using a buck/boost or SEPIC. Still just one more IC, though.

author: veryevil
author_rank: Unknown
timestamp: February 27, 2014, 05:05:57 pm
content: Quote from: b2theory on February 27, 2014, 04:56:15 pmIf possible I would like it to run from battery and if plugged into USB continue to run and charge the battery.Would also be nice to be able to use it without a battery and only in usb mode if thats not an extra complication?

author: treespicer
author_rank: Newbie
timestamp: February 27, 2014, 05:13:30 pm
content: Quote from: veryevil on February 27, 2014, 05:05:57 pmYes, the aforementioned BQ2407x family will handle this for you. That's the "power path" functionality.
looking for a long gear/extruded spur gear - Page 1
Forum section: electronics / projects

author: dequo
author_rank: Contributor
timestamp: April 08, 2011, 07:36:40 am
content: I need a long gear for a project, im sure theres a name for what i want but i havent been able to find anything.It needs to be like a cylinder with teeth going lengthways, the opposite of a worm gear almost. the rest of the project can be adapted to its pitch diameter etc. Preferably a diameter of 35mm and about 10cm long.i have though of getting it custom made but im sure somebody would sell something like this..

author: GeoffS
author_rank: Unknown
timestamp: April 08, 2011, 07:53:41 am
content: Look up timing belts or pulleys and you/ll find something likethis:is this what you're after?

author: dequo
author_rank: Contributor
timestamp: April 08, 2011, 08:22:57 am
content: yeah pretty much that but it needs to be able to mesh properly with a spur gear. the thread on that looks more rectangular

author: RayJones
author_rank: Frequent Contributor
timestamp: April 08, 2011, 09:17:32 am
content: Does the word "pinion" help?

author: DaveW
author_rank: Frequent Contributor
timestamp: April 08, 2011, 09:33:32 am
content: How about this,http://www.hpcgears.com/products/toothed_bar_stock.htmHPC are very good, had them make some custom gears for me for robot wars, was surprisingly cheap

author: mjkuwp
author_rank: Unknown
timestamp: April 08, 2011, 12:52:33 pm
content: Do you need one for a one-off project, or a supply of them for production? it makes a difference. Also you describe the gear as "tall" but specifiy 10mm thick by 35mm DIA... which seems short and fat. Is the difference semantics? or a typo? I guess relative to a lot of things I see 10mm thick would be unusual but I just wanted to make sure.

author: dequo
author_rank: Contributor
timestamp: April 11, 2011, 06:05:02 am
content: i think daveW wins this time, thanks mate
Looking for a MOSFET - Page 1
Forum section: electronics / projects

author: akis
author_rank: Frequent Contributor
timestamp: April 29, 2017, 09:18:06 pm
content: I have been using a pair of IRFSL4615PBF to switch an AC signal at 200KHz, 180V p2p and around 1A RMS. I was looking for something similar but at higher Vds, say 200V rather than 150V. Coss has to be low (below 200pF) so there are no leaks when the FETs are off, and switching time is not that important (1 switch per second). Been to the Infineon web site their parametric search is primitive does not include the Coss or other params. About to visit ON Semi now, and any suggestions welcomed.

author: MagicSmoker
author_rank: Super Contributor
timestamp: April 29, 2017, 09:47:05 pm
content: Good grief, you are going about this bass-ackwards... Do a parametric search at a distributors website, instead of going to each manufacturer individually, and filter on, say, a specific package and voltage rating to narrow down the field of contenders.Here in the states I prefer Mouser and Digikey, but my understanding is that Farnell and RS Components are more popular in the UK.

author: akis
author_rank: Frequent Contributor
timestamp: April 30, 2017, 06:17:50 am
content: Thanks MagicSmoker, I have already been to Farnell, Mouser and Digikey and RS and they do not include Coff in their parametric search.

author: Marco
author_rank: Super Contributor
timestamp: April 30, 2017, 08:05:48 am
content: Quote from: akis on April 30, 2017, 06:17:50 amYou don't really need it, next to no MOSFET with 200-300 max Vds and single digit amp max current will have Coss exceeding your requirements.You can find some a lot cheaper than blueskull's expensive hammer too

author: MagicSmoker
author_rank: Super Contributor
timestamp: April 30, 2017, 02:08:28 pm
content: Quote from: akis on April 30, 2017, 06:17:50 amNo they don't, but if you filter on package (TO-262), Vds rating (200V) and must be in stock then you get exactly 1 result at Digikey. Download the datasheet, check Coss, profit.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: April 30, 2017, 02:13:41 pm
content: Quote from: blueskull on April 30, 2017, 06:52:57 amOne-upsmanship, is it?Relay. 250VAC, 10A, < 20mR, <10pF. Requires standard SMT or THT assembly process.(No mention of how often the switch needs to be switched, so I claim this is a valid solution until further information is given.)Tim

author: D-Jack
author_rank: Contributor
timestamp: April 30, 2017, 11:02:26 pm
content: Quote from: akis on April 29, 2017, 09:18:06 pmYou can use IPN60R3K4CEATMA1, also from Infineon:https://www.digikey.com/product-detail/en/infineon-technologies/IPN60R3K4CEATMA1/IPN60R3K4CEATMA1CT-ND/6138212

author: Fungus
author_rank: Super Contributor
timestamp: May 01, 2017, 01:22:13 am
content: Quote from: T3sl4co1l on April 30, 2017, 02:13:41 pm...apart from the part where it says "1 switch per second".

author: T3sl4co1l
author_rank: Super Contributor
timestamp: May 01, 2017, 04:31:10 am
content: Quote from: Fungus on May 01, 2017, 01:22:13 amIt's great how my eyes skim over things like that
Looking for a motor driver 48V 3kW - Page 1
Forum section: electronics / projects

author: Simon
author_rank: Unknown
timestamp: October 22, 2023, 04:34:31 pm
content: I have a bit of a problem. I can get a motor that will do 3kW at 48V but it seems to be quite difficult to find a driver for it. This requires an AC drive as it is a PMAC or "servo" motor. We don't actually need any fancy control, just to get to a speed.

author: johansen
author_rank: Super Contributor
timestamp: October 22, 2023, 05:47:11 pm
content: Ebike controller.

author: Simon
author_rank: Unknown
timestamp: October 22, 2023, 07:54:09 pm
content: Well I was after something that is not flavor of the month in china only to find that it disappears on us. Way back I was recommended a particular motor, a year later I go looking for it (it was everywhere a year ago) only to see it replaced by another. You can't make CE/UKCA products on that basis, at some point the company no longer releases new products as it spends all it's time "maintaining" existing ones.

author: langwadt
author_rank: Super Contributor
timestamp: October 22, 2023, 07:59:57 pm
content: https://robotdigg.com/product/1768/48V-DC-BLDC-motor-driver-60A-or-75A

author: Dave
author_rank: Super Contributor
timestamp: October 22, 2023, 08:01:25 pm
content: Curtisprobably sells something that would fit your needs. They operate in UK as well.

author: Simon
author_rank: Unknown
timestamp: October 22, 2023, 08:18:59 pm
content: Yes that is a good idea, hopefully their supply issues are somewhat resolved, in the past we had trouble getting stuff.
Looking for a p-channel mosfet for designing a current source - Page 1
Forum section: electronics / projects

author: sean87
author_rank: Regular Contributor
timestamp: May 30, 2016, 09:37:43 pm
content: Hi all,I want to design a current source (at least 1A capable, but higher is better) on a PCB, so I am looking for a p-channel enhancement or depletion MOSFET. The base of my design is this application of MAX9611 chip:I am not sure if I need the enhancement or depletion type...maybe you can clarify what are the major differences between the two? I would also appreciate it if you can give me a part number, it better be a SMD one.Thanks!

author: stefanh
author_rank: Contributor
timestamp: May 30, 2016, 10:35:55 pm
content: Look at the MOSFETs used in the evaluation kit and peripheral module designs for some ideas.https://datasheets.maximintegrated.com/en/ds/MAX9611EVKIT.pdf1.49A, 30V p-channel MOSFET(3 SOT23)Vishay Si2303BDS-T1-E3https://datasheets.maximintegrated.com/en/ds/MAX9611PMB1.pdf2.2A, 30V p-channel MOSFET(3 SOT23)Vishay Si2303CDS

author: zlymex
author_rank: Frequent Contributor
timestamp: May 31, 2016, 04:48:45 am
content: That Vishay pFET(Si2303CDS) is virtually useless for 1A current source because its very small dissipation and very narrow SOA(Safe Operating Area).You need a proper enhanced type(most of PMOS are) of at least 50 Watts if the current source is operating at 12V and >=1A.There are a lot of thru-hole TO220 packaged PMOS available such as IRF4905 and IRF5210, since you have to use a heat-sink and TO220 package is easy for mounting that.

author: metzjtm
author_rank: Contributor
timestamp: May 31, 2016, 05:57:10 am
content: This should answer your enhancement or depletion questions. There is some math that needs to be done before you can select a power mosfet. What type load, min current, max current, inrush, voltage. Time of each. It will take just a little more data.edit: I forgot the linkhttp://www.electrical4u.com/mosfet-working-principle-of-p-channel-n-channel-mosfet/

author: Cicada
author_rank: Regular Contributor
timestamp: May 31, 2016, 07:20:13 am
content: Look at the first three paragraphs of this wikipedia article.https://en.wikipedia.org/wiki/Depletion_and_enhancement_modesPut differently:Enhancement mode = Almost works like Normally open switch. You have to apply voltage to the gate for the FET to conduct current.Depletion mode = Almost works like Normally closed switch. You don't have to apply voltage to the gate for the FET to conduct current. When you apply a voltage it stop conducting.I used this p Channel Depletion mode FET in a design of mine some time back.http://bit.ly/1U9DuO2Terrible on resistance. I had to parallel three of them to get decent conduction through them.Look at attached pic for Gate voltage versus FET resistance.THIS WILL PROBABLY NOT WORK FOR YOUR APPLICATION. But look at the datasheet. I pass it on because Depletion mode P channel FETs are actually a rare thing to find.

author: Cicada
author_rank: Regular Contributor
timestamp: May 31, 2016, 07:37:50 am
content: Maybe this one will work better. MMBFJ175http://bit.ly/1PeFpov
Looking for a panel/bulkhead mount power switch - Page 1
Forum section: electronics / projects

author: dcarr
author_rank: Regular Contributor
timestamp: October 26, 2018, 07:22:56 pm
content: Hi EEVblog,I'm working on a product that has 3-5 AC power bricks inside and for cosmetic reasons I need to bring them out of the box as a single AC power cord + external power switch. The product is in a ~12x6x8" metal case. Volume is low 100s of units.In my mind the perfect solution would be a small bulkhead mount IEC power receptacle+switch that has a standard US power plug on the inside. I could add a cutout to case to mount the unit "through the wall" and then plug a standard power strip into it on the inside. Another option would be power strip with the switch on the front and the power receptacles on the back.Any ideas would be greatly appreciated!David

author: Gribo
author_rank: Frequent Contributor
timestamp: October 26, 2018, 07:32:37 pm
content: Have a look at Schruter's catalog (No affiliation) Hopefully you will find something there.

author: t1d
author_rank: Super Contributor
timestamp: October 27, 2018, 01:14:18 am
content: Not exactly what you mean, but these come in many shapes/sizes/feature combinations. Cheap as chips, on Ebay.https://www.ebay.com/sch/i.html?_from=R40&_trksid=m570.l1313&_nkw=ac+power+socket+with+fuse&_sacat=0

author: Gregg
author_rank: Super Contributor
timestamp: October 27, 2018, 04:19:23 am
content: Assuming from your description, you are looking to plug 3 to 5 wall warts inside a metal box and have a switch on the outside. If so, you may want to address cooling of the power supplies in your design.I would go with the IEC switched/fused/pilot light combination input mentioned earlier and make a baffle plate across one side of the box to separate the mains power from low voltage power. Then install the receptacles in the baffle. Search for snap in receptacles and snap in outlets like thishttps://www.ebay.com/itm/Qualtek-739W-X2-20-125-VAC-20-A-Receptacles-Snap-In-lot-of-20/253600681118You can also get them without the ground and they take up a lot less room if your wall warts only have two prong plugs.Be sure to ground the box, should go without saying, but if I don't somebody else will.

author: LapTop006
author_rank: Unknown
timestamp: October 27, 2018, 08:19:03 am
content: Quote from: dcarr on October 26, 2018, 07:22:56 pmAll different enough that you can't simply use a single supply brick?
Looking for a PCB-mount female 20 way box header - Page 1
Forum section: electronics / projects

author: 741
author_rank: Frequent Contributor
timestamp: February 20, 2023, 08:52:16 am
content: HiI can't seem to find a 20 position, 2 row female box header (like the 'edge-mounted' connector seen herehttps://www.olimex.com/Products/ARM/JTAG/ARM-JTAG-20-10/) in Mouser or FarnellWhat are the right keywords when searching for the above?

author: 741
author_rank: Frequent Contributor
timestamp: February 20, 2023, 08:56:05 am
content: OK I might have found a better search phrasewire-to-board, 2.54 mm, 2 rows, 20 contacts, through hole straight, receptaclehttps://uk.farnell.com/c/connectors/pcb-receptacles?st=wire-to-board%2C+2.54+mm%2C+2+rows%2C+20+contacts%2C+through+hole+straight%2C+receptacle&showResults=true
Looking for a pixel or character display that would fit inside Casio F-91W - Page 1
Forum section: electronics / projects

author: dusan
author_rank: Regular Contributor
timestamp: October 11, 2024, 11:28:01 am
content: I'm looking for any character or pixel display that would fit inside Casio F-91W. I am aware of custom F-91W board but they reuse original display which is only numeric, I really need characters and generally bit more data.I found these (untested if they actually fit but they are small):- 0.42" 72x40 SSD1306 -https://www.aliexpress.com/item/33028790938.html)- 0.96" 80*160 ST7735 - various smart wristbands use thesehttps://www.aliexpress.com/item/1005001598020071.html- 0.66" 64x48 -https://www.aliexpress.com/item/1005006233779243.html- 0.95" 96x64 SSD1331 -https://newhavendisplay.com/0-95-inch-full-color-oled-glass/If any of you know of any other display I would like to know. Also if you have different combination of watch body donor + display share them too, I'm not dead set on F-91W. But it has to be cheap, cause I'm cheap

author: I wanted a rude username
author_rank: Frequent Contributor
timestamp: October 12, 2024, 08:37:59 pm
content: It's a difficult problem.The OLEDs are small enough, but they suck down a lot of power. If you could source a Sharp LS010B7DH02, that might be about right, and it's a transflective LCD so it's super efficient in comparison.You'll need to figure out how to interface with the pushers/buttons, way harder than it sounds to make this reliable and manufacturable.

author: edavid
author_rank: Super Contributor
timestamp: October 12, 2024, 10:21:26 pm
content: Would a TI Chronos watch work? You can still get them on eBay.
Looking for a programmable (I2C) buck regulator Vin=39-52v  Vout 0-25v   5-10A   - Page 1
Forum section: electronics / projects

author: Odd
author_rank: Regular Contributor
timestamp: December 18, 2023, 12:53:25 pm
content: The goal is to have an (safe) option to set output voltage.I have limited a search to:https://eu.mouser.com/c/semiconductors/power-management-ics/voltage-regulators-voltage-controllers/switching-voltage-regulators/?input%20voltage%2C%20max=55%20V~~56%20V%7C~58%20V~~70%20V&output%20current=3%20A~~25%20A&topology=Buck&rp=semiconductors%2Fpower-management-ics%2Fvoltage-regulators-voltage-controllers%2Fswitching-voltage-regulators%7C~Input%20Voltage%2C%20Max%7C~Output%20Currentbut still, I see none of the qualifying switchers being programmable,A "perfect" part would have current sensing and programmable voltage...Or I will need to use a digital potentiometer..

author: Berni
author_rank: Super Contributor
timestamp: December 18, 2023, 01:08:25 pm
content: You can use a DAC to make any switching regulator with a feedback loop into a programmable one.Potentiometers also work but are annoying because they have to be used in rheostat mode (otherwise one side gets to too high of a voltage) and this makes the response rather non linear, made worse by the usually small 7bit or so resolution of digital pots.Just connecting a DAC output to the FB pin via a resistor gives you a nice linear relationship and DACs tend to be higher resolution.As for current sensing, that is a pretty rare feature. Likely gonna have to use a high side shunt amplifier for that. But you can likely use the same DAC trick to adjust the current limit (when it is set by a resistor on a pin)

author: coromonadalix
author_rank: Super Contributor
timestamp: December 18, 2023, 02:21:31 pm
content: or use digital pots ic's .... they seems to be very linearsome of them are i2c compatible ??

author: PCB.Wiz
author_rank: Super Contributor
timestamp: December 18, 2023, 11:43:31 pm
content: Quote from: Odd on December 18, 2023, 12:53:25 pmDigital or other external control, would allow you to focus on the V-I specs more, as i2c is still somewhat rare.For Digital pots, you will need a Voltage Reference plus a 'good' Digital Pot.The voltage reference is to inject a small current, so you can adjust below the VREF of the controller, to 0V, and a Pot with low ppm and low % tolerance, is needed.That limits you mainly to ADI and there, 1024 steps is the top.There are non volatile DACs, which come up to 12b, which may be better ? TI and Microchip offer these.If you need additional range-control, there are i2c EEPROM DIP SW replacements.Or, you could use a MCU as a non volatile set point, either one with a good DAC included, or a PWM DAC may be OK for voltage settings.For slow-dac setpoints, it is common to run two 8b PWMs with scaled resistors, to create a 16b DAC.
Looking for a proven power supply circuit diagram - Page 1
Forum section: electronics / projects

author: avitsur
author_rank: Contributor
timestamp: October 02, 2021, 09:31:36 am
content: Hi, I'm asking for your help. I'm looking for a circuit diagram of 0-30vdc power supply with a current limit 0-1 or 2amps. I know that there are many circuits that needs only to google, but I would like to ask for one that is proven and surely works. thanx.
looking for a psu schematic with plans for laser printing a pcb - Page 1
Forum section: electronics / projects

author: p.larner
author_rank: Frequent Contributor
timestamp: December 18, 2023, 09:54:37 am
content: has anyone plans for a psu with a layout for laser printing onto a pcb toner transfer method?,i have an old millitary psu with a blown up control board,it has lots of taps from 3v to 43v,its about 7 inches square i want to buld a 0-60v 0-30a unit if poss with cc+ cv.

author: coromonadalix
author_rank: Super Contributor
timestamp: December 18, 2023, 11:33:01 am
content: https://www.eevblog.com/forum/testgear/power-supply-schematics-406077/msg5223684/#msg5223684adapt to your own needs

author: p.larner
author_rank: Frequent Contributor
timestamp: December 18, 2023, 07:39:27 pm
content: i was looking for the pcb artwork mostly with schematic.thanks for your help tho.

author: Gyro
author_rank: Super Contributor
timestamp: December 18, 2023, 08:18:02 pm
content: You don't need artwork specific to toner transfer etching, although a long and time honored PCB making method is to use photocopies of the PCB artwork in magazine articles (you might actually want to look through magazine archive sites, eghttps://www.worldradiohistory.com/index.htmIt's a shame old Elektor issues have become hard to find). These days, mirror imaging , capturing, scaling, cleaning up etc. are simple tasks.

author: p.larner
author_rank: Frequent Contributor
timestamp: December 18, 2023, 10:34:41 pm
content: found this but the 723 is good for 37v max does the zenner going thru the 100k resistor to pin 10 on the 723 lower the input to a safe voltage for the 723?,may need to zoom in as its a screen shot ok,cheers.

author: coromonadalix
author_rank: Super Contributor
timestamp: December 19, 2023, 11:50:26 am
content: use 723 in floating mode .... you could design higher voltages output
Looking for a Qi charging module. - Page 1
Forum section: electronics / projects

author: phil from seattle
author_rank: Super Contributor
timestamp: July 20, 2025, 08:22:03 pm
content: I am looking for a good quality Qi charging module (AKA transmitter) that includes PCB and coil. There are lots of them out there but reviews are pretty brutal. I foundone at Adafruitwhich could work for me but the PCB is big and it's pretty expensive compared to all the others. I want it to work with cell phones - I'm making a phone holder for a vehicle that will also charge - without having to fiddle with USB connectors.Does anyone have suggestions for known good Qi charging modules? Small PCB is good. Bonus if it works well with Apple devices. 5W limit is fine.

author: Marco
author_rank: Super Contributor
timestamp: July 21, 2025, 07:30:57 am
content: I'd look for Qi2, the standardization is much better. Dunno if it's any good, but Taidacent has one on ali/amazon.Or just take something like the Anker Zolo Qi2 puck and bodge it.
Looking for a Rechargeable mini UPS based on Lithium-ion cr32 Battery or... - Page 1
Forum section: electronics / projects

author: ziomario
author_rank: Contributor
timestamp: January 26, 2025, 04:28:11 pm
content: Hello to everyone.I'm trying to "create" a DiY tablet or maybe it's better to say "mobile" device and I'm looking for a Rechargeable mini UPS based on Lithium-ion cr32 Battery (or any other small battery size) pack at 12V 3000mAh to power on my DiY tablet (it runs with the rockpro rk399 based board).It should be like this one :https://www.amazon.co.uk/TalentCell-Rechargeable-3000mAh-Lithium-External/dp/B072HR211Pbut it should accept the cr32 batteries (or any other small battery,like the Nokia BL-5C 1020mAh 3.7V 3.8Wh) that occupies a small space inside the case.Thanks.
Looking for a replacement for this capacitor - Page 1
Forum section: electronics / projects

author: Tectonic
author_rank: Contributor
timestamp: January 17, 2014, 05:42:33 pm
content: The pictures are from the power module of an Agilent 6622A power supply. I want to replace the capacitor but I'm not certain what part I should order from mouser/digikey. The Agilent part number is 5060-3218. I haven't found a cross reference of the manufacturer's model # for this.Any idea what I could use to replace it?

author: Monkeh
author_rank: Super Contributor
timestamp: January 17, 2014, 05:44:00 pm
content: Why do you want to replace it?

author: Tectonic
author_rank: Contributor
timestamp: January 17, 2014, 05:51:41 pm
content: The unit won't power up and I suspect a bad capacitor. I haven't yanked it out yet but I'm getting ESR measurements that fluctuate between 4 and 80 ohms for this capacitor. It's possible there are two more blown capacitors on that module.

author: Monkeh
author_rank: Super Contributor
timestamp: January 17, 2014, 05:53:15 pm
content: Quote from: Tectonic on January 17, 2014, 05:51:41 pmYank it and test it. Be aware that there is a resistor across it in circuit.. These caps rarely fail in any manner other than explosively or open circuit, and shouldn't affect operation anyway.

author: Greg Robinson
author_rank: Regular Contributor
timestamp: January 17, 2014, 06:02:11 pm
content: Digikey

author: Tectonic
author_rank: Contributor
timestamp: January 17, 2014, 06:12:23 pm
content: There are two more capacitors. These come up as 328 ohms each on my meter.

author: Monkeh
author_rank: Super Contributor
timestamp: January 17, 2014, 06:15:18 pm
content: They're RFI suppression caps. They really have no functional impact on the power supply.

author: Tectonic
author_rank: Contributor
timestamp: January 17, 2014, 06:21:23 pm
content: Thanks for the info. I'll probe around some more and see if I can find out why it won't power up.
looking for a rugged VFD - Page 1
Forum section: electronics / projects

author: Simon
author_rank: Unknown
timestamp: August 31, 2023, 09:07:55 am
content: We are looking to use an electric motor in an off road scenario. Now but for the lack of IP rating (easily fixed I am sure) but more seriously any sort of shock resistance we could use an industrial VFD. But we are not sure that an off the shelf industrial VFD will take being mounted to a vehicle that goes off road.Anyone ever done this or know of ruggedized VFD's ?

author: jpanhalt
author_rank: Super Contributor
timestamp: August 31, 2023, 10:06:40 am
content: VFD's are universal in EV's and off-road EV's (apparently). Are replacements for the "inverter" available? Surely they are shock tested, but the results may not be publically available.

author: Simon
author_rank: Unknown
timestamp: August 31, 2023, 10:38:44 am
content: yes but this is for your off the shelf induction motor, industrial VFD's are very cheap, less than £1'000 for 10kW but I would not expect them to be designed to be bounced along in a vehicle much.

author: jpanhalt
author_rank: Super Contributor
timestamp: August 31, 2023, 10:56:15 am
content: Why would a profit-making company make a ruggedized VFD for a piece of industrial equipment that will be bolted to a floor? Are wrecked and not burned EV's around? I don't have an EV, but I am not a stranger to Route 60 Automotive "recycler" in Ohio and others elsewhere. They are good places for good parts at a small fraction of the cost for OEM parts.

author: Simon
author_rank: Unknown
timestamp: August 31, 2023, 11:01:58 am
content: Yes potentially used EV parts could be used but it makes it more difficult to make consistent products over time as we are reliant on scrap.No I don't expect people making VFD's for fixed indoor installation to go beyond that, which is why I am asking, is there anything better. I can get a BLDC motor and driver no problem, but that is quite costly at the power we require. This is not to move the vehicle. It is other equipment.
Looking for a sensitive magnetometer (breadboard compatible) - Page 1
Forum section: electronics / projects

author: Obin
author_rank: Contributor
timestamp: July 28, 2022, 10:09:24 am
content: Wow it's been ages since i've been on this forum! It looks like i'm searching for something that's pretty hard to find, so I thought to use the collective EEVbrain to help me in this endeavour.For my students (basic course for the first year of college) I'm making some basic analog circuits for them to build and become familiar with different concepts. I had the idea to let them build a compass, that lights an LED when they point their board north, roughly. But to achieve this, I need a PDIP (or something breadboard compatible, prefferably) magnetometer with an analog out, capable of measuring the earth's magnetic field.I've tried one in a TO-92 package from TI, but it appeared to be a normal hall effect sensor. (Amplifying the cr*p out of the output to make it more sensitive didn't work, worth the try)Anyone familiar with a component that could work for this?I was thinking of something like Power supply -> magnetometer -> comparator -> LED (again, first years)Thanks!

author: ledtester
author_rank: Super Contributor
timestamp: July 28, 2022, 01:58:54 pm
content: Quote from: Obin on July 28, 2022, 10:09:24 amIf you find an SMD component how about making your own through-hole adaptor using breakout boards like:https://www.amazon.com/KeeYees-Adapter-SOT223-TQFP100-2-54mm/dp/B085L8SK7Z/There are flying lead devices like:https://www.wuntronic.de/en/fluxgate-magnetometer-with-analog-output.htmlbut I suspect they are going to be expensive.

author: Obin
author_rank: Contributor
timestamp: July 28, 2022, 02:32:43 pm
content: Yes, ideally the component would not be very expensive (<5 euros/piece). The destructive nature of electronics students can be unforgiving

author: eugene
author_rank: Frequent Contributor
timestamp: July 28, 2022, 02:46:55 pm
content: Since they started putting one of these in every cell phone, they've become inexpensive and plentiful. The problem is that most of them are in tiny packages and use a digital interface (I2C or SPI) though I know that analog versions do exist. Fortunately, the maker community likes things like this, so the vendors that support makers with Arduinos, etc make break-out boards with them installed. The largest in the US isAdafruit, but there are others, probably in your country. Or at least someone that retails things like this.EDIT: not all of these are sensitive enough to use as a compass. Make sure you know what you're buying.

author: rooppoorali
author_rank: Regular Contributor
timestamp: July 29, 2022, 01:38:07 pm
content: You can consider Adafruit LSM9DS0https://learn.adafruit.com/adafruit-lsm9ds0-accelerometer-gyro-magnetometer-9-dof-breakouts
Looking for a SERIAL TO PARALLEL MULTIPLEXER/REGISTER, does it exist? - Page 1
Forum section: electronics / projects

author: Halban
author_rank: Contributor
timestamp: January 25, 2024, 11:29:09 am
content: Hello guys!I'm looking for a 8-channel output register.I want to set independent output levels (0V or 5V) thanks to an already-existing 3 select pins ABC.A draft to explain what I imagine :This kind of IC already exist?PS : the output selection ABC signals are already generated by my PCB and are sequenced like on the picture above.I really need to to use these signals like described.Thanks a lot!Halban

author: PSR B1257
author_rank: Frequent Contributor
timestamp: January 25, 2024, 11:43:46 am
content: QuoteSure. 3to8 Decoder: 74238

author: selcuk
author_rank: Frequent Contributor
timestamp: January 25, 2024, 11:54:14 am
content: I think you need an addressable latch. 74259 etc.

author: Halban
author_rank: Contributor
timestamp: January 25, 2024, 03:58:34 pm
content: Thanks a lot for your help!Indeed the 74HCT259 looks perfect for my use, thanks to its "Addressable latch" mode.Have a nice day!Best,
Looking for a simple Power Management IC for powering an SoC - Page 1
Forum section: electronics / projects

author: unturned3
author_rank: Contributor
timestamp: July 21, 2022, 08:32:29 am
content: Hello!I'm designing a circuit around anSoCthat requires 5 power rails (3.3, 3.0, 2.5, 1.8, 1.1 volts). Does anyone know if there's a PMIC that can supply these 5 voltages (ideally with a small footprint and minimum external components)? I was thinking about using five LDOs, but thought maybe there's some dedicated chip out there that can simplify this task.Thank you.

author: Terry Bites
author_rank: Super Contributor
timestamp: July 21, 2022, 03:48:56 pm
content: https://www.digikey.co.uk/en/products/filter/pmic-voltage-regulators-dc-dc-switching-regulators/739?s=N4IgTCBcDaIAoFkCSBhEBdANCAbFUAlgCZQgAcA7CNgA4AupAynQE4EB2A5tSHQJ40ApqSIBnAMYgAvlKAgood luck with finding stock

author: rooppoorali
author_rank: Regular Contributor
timestamp: July 23, 2022, 11:51:53 am
content: If you're using Raspberry Pi, then you may find this discussion helpful:https://forums.raspberrypi.com/viewtopic.php?t=41642

author: unturned3
author_rank: Contributor
timestamp: July 24, 2022, 02:15:04 am
content: Quote from: Terry Bites on July 21, 2022, 03:48:56 pmThanks, I'll take a look. Maaaybe I can get away with 4 power rails instead of 5...

author: unturned3
author_rank: Contributor
timestamp: July 24, 2022, 02:17:18 am
content: Quote from: rooppoorali on July 23, 2022, 11:51:53 amI'm not using a Raspberry Pi, and a LM7805 won't supply any of the 5 voltages that I need...