hybridfree/eevblog-posts huggingface dataset:
UJTs PUJTs ? - Page 1
Forum section: electronics / projects

author: Terry Bites
author_rank: Super Contributor
timestamp: August 07, 2024, 02:54:58 pm
content: Does anyone design in unijuctions any more or do they just exist because people still buy them by accident?They were obsolete when I started out in the early 80s.Other than 70s dimmer switches and hoplesly drifty timers what purpose do the serve now?Any one got a rational application?2

author: Xena E
author_rank: Frequent Contributor
timestamp: August 07, 2024, 06:52:08 pm
content: Design no, however a couple of built to order legacy products using them for phase angle triggering of thyrisor/triac industrial power controllers, one for a vibratory conveying system, the other a magnetic reluctance VSD.Both units use the obsolete 2N2646 of which the remaining stock is watched carefully, it's not that they can't be re-engineered, I just don't think they will: at least not for the VSD anyhowI didn't think anyone actually still made them?Regards,X.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: August 07, 2024, 07:22:11 pm
content: Even PUTs are obsolete (or getting there) now; most things they were used for, have been simplified (e.g. dimmers with DIACs) or integrated (timers; ASICs with osc/counter/MCU/etc.; regulators/controllers with built-in fault circuitry; etc.).Tim

author: PCB.Wiz
author_rank: Super Contributor
timestamp: August 08, 2024, 05:14:42 am
content: Quote from: Terry Bites on August 07, 2024, 02:54:58 pmVariant parts like DIAC and break over diodes are still made in volumes, but 3 or 4 terminal parts are very rare.You can buy a NPN+PNP pair (possibly with inbuilt resistors) in a SOT353 package and make your own, should youreallyneed to.

author: coppercone2
author_rank: Super Contributor
timestamp: August 08, 2024, 06:28:10 am
content: I feel like we are not smart enough to figure out how to use them right
UK: Attaching festive lights to house - Page 1
Forum section: electronics / projects

author: NivagSwerdna
author_rank: Super Contributor
timestamp: November 02, 2017, 05:50:41 pm
content: Tis the season... almost...I would like to wire some strings of addressable LEDs to the outside of my house but I do not want to damage the house too much... the runs will be either up the walls or along the wooden window frames, soffits etc...I only intend the lights to be up in December. Any suggestions for fixings? The fixings can stay attached.

author: macboy
author_rank: Super Contributor
timestamp: November 02, 2017, 06:20:32 pm
content: I decided that:- It's too much work- The plastic clips to hold the light strings get brittle and break after 1 season in the sun/cold.- It's dangerous up there on a ladder- LED light strings keep failing.- it damages the shingles/siding/houseNow I put a couple of Laser projectors similar to these on my lawn and I'm done.

author: NivagSwerdna
author_rank: Super Contributor
timestamp: November 02, 2017, 06:26:34 pm
content: You are probably right. I have now come across...andbut it is a lot of work

author: Gyro
author_rank: Super Contributor
timestamp: November 02, 2017, 09:24:16 pm
content: By coincidence the CPC Christmas lighting flyer dropped through the letterbox today. It included these gutter hooks:http://cpc.farnell.com/search?st=gutter%20hooksMight or might not be applicable depending on whether you have convenient guttering!

author: NivagSwerdna
author_rank: Super Contributor
timestamp: November 03, 2017, 10:38:52 am
content: Quote from: Gyro on November 02, 2017, 09:24:16 pmThat might work for some parts.

author: Ian.M
author_rank: Super Contributor
timestamp: November 03, 2017, 10:57:58 am
content: You'd be better off and safer fixing a Rawl Eyebolt up under the eaves either side of the front of the house, a minimum of two whole bricks from the corner, attaching blocks (pulleys) to the eyes, and threading a long Dyneema rope through them to hoist a coarse net carrying whatever illuminations you want. (You need a low stretch rope like Dyneema across the top of the net so you can get it tight enough to minimise sagging.) You'll also need some large cleats near ground level below the blocks to secure the hoisting rope and lines from the bottom corners of the net to. If the house front is particularly wide or not straight, you may need extra hoisting points in the middle. Hold the net out away from the house front so it doesn't snag on window frames and other protrusions while hoisting or lowering it.Its probably best to remove the rope completely for the rest of the year, and figure on swapping out the blocks for a spare set next year so the old set can be cleaned and lubricated for reuse without extra ladder work. Ideally you'd remove the blocks when you take the lights down so they don't get weathered for a year and possibly seize, but that's more ladder work and shortly after the festive season over-indulgence at that.
UK source of solder paste? - Page 1
Forum section: electronics / projects

author: deephaven
author_rank: Frequent Contributor
timestamp: December 27, 2013, 08:55:38 pm
content: Anyone got any suggestions on where to get (preferably lead free) solder paste from in the UK? I only intend using it for a few prototypes, not production, so don't need huge quantities of it.

author: jc101
author_rank: Frequent Contributor
timestamp: December 27, 2013, 10:24:47 pm
content: Rapid have small packs....http://www.rapidonline.com/Tools-Equipment/Edsyn-CR11-No-Clean-SMD-Solder-Paste-Content-10-g-50-4943...or is that too small for your needs?

author: deephaven
author_rank: Frequent Contributor
timestamp: December 27, 2013, 10:42:44 pm
content: Quote from: jc101 on December 27, 2013, 10:24:47 pmThanks, that would probably be enough - I'll know when I start using it! A bit expensive for such a small amount though.

author: Monkeh
author_rank: Super Contributor
timestamp: December 27, 2013, 10:50:26 pm
content: I have used this with success:http://www.ebay.co.uk/itm/121033065108The lead free (why?!) version:http://www.ebay.co.uk/itm/121033067714Love to use branded stuff, but £30 is a hell of an outlay for something with a shelf life.

author: deephaven
author_rank: Frequent Contributor
timestamp: December 28, 2013, 04:51:58 pm
content: Quote from: Monkeh on December 27, 2013, 10:50:26 pmThanks, Monkeh, those prices look very reasonable. I mentioned lead free because I may end up selling the prototype to a customer and will have to abide by the regs.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: December 28, 2013, 05:15:02 pm
content: Quote from: deephaven on December 28, 2013, 04:51:58 pmI really wouldn't worry about that, unless the clustomer is likely to actually test itI'd tend to avoid general distributors like Rapid for paste as it may have been hanging around for a while, and may not have been stored at a low temp.

author: deephaven
author_rank: Frequent Contributor
timestamp: December 28, 2013, 05:28:32 pm
content: Quote from: mikeselectricstuff on December 28, 2013, 05:15:02 pmI'm sure my customer won't test it, but I did sign a declaration!Where do you get yours from, Mike?
UK supplier for one off 3D printed SLS nylon - Page 1
Forum section: electronics / projects

author: perdrix
author_rank: Frequent Contributor
timestamp: May 14, 2024, 10:55:50 am
content: I needed to order a 3D printed part here in the UK, and found alot of sites all of whom had fairly high minimum order values.In the end I reverted to using Shapeways even though shipping from EU is a bit costly.And recommendations for 3D printing companies that offer similar capabilities to Shapeways but are based in UK and don't apply high MOV?PS to moderators: I'm posting this here rather then the 3D Printing section as that section seems more about the how-to of 3D printing rather than finding a supplier.CheersDavid
UK/EU sources for fusible resistors - Page 1
Forum section: electronics / projects

author: philpem
author_rank: Frequent Contributor
timestamp: January 02, 2014, 01:23:27 am
content: Hi guys,I've got a switchmode power supply on the bench, which I'm close to fixing. Thus far I've replaced a blown fuse, bridge rectifier, chopper transistor and a few toasted (but not completely blown) resistors. Last but not least, I need to replace two fusible resistors -- a 0.33R (orange-orange-silver-gold) and a 220k (red-red-yellow-gold).But surprisingly, none of the usual suspects (Farnell, RS, et al) seem to sell these, and JPG Electronics (the only source of fusible resistors I could find) only have the 0R33, and only in a half-watt variety (I suspect these may be a little meatier). Even the Great Internet Tat Bazaar (erm... Ebay) has failed me...Does anyone know of a source of these elusive beasts?The resistors are both 15mm long, coated in a grey matt finish with the colour code printed on top. I've attached a photo of them below.Thanks,Phil.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: January 02, 2014, 01:30:03 am
content: Bear in mind the primary difference between fusible and normal resistor is the former is not supposed to catch fire when overloaded.for 0R33, three smaller 1Rs in parallel would work.I wouldn't worry about the 220K - just use a normal one. Highly unlikely you'd get a 220K to get hot enough to catch fire.

author: philpem
author_rank: Frequent Contributor
timestamp: January 02, 2014, 02:05:36 am
content: Quote from: mikeselectricstuff on January 02, 2014, 01:30:03 amIt looks like the 220k is actually fine; I desoldered it and checked it out of circuit and it came up at a little over 220k, so I soldered it back in. The 0R33 is well and truly cooked, though - blown open. Swapped that for a couple of 1R carbon films in parallel to test; that resistor is between the source of the FET and the rectified AC, or what the UC3842 might call "ground". Still no go, brief pulse of a few hundred mV then zero output.Started working backwards, 0.02V between UC3842 VCC and GND. Meter reports a short in both directions. Desoldered everything on that leg except the 3842, but still reading a short. Looks like the 3842 took a 320V whack when the FET died (full on G-D-S short). I've got an IRF740 in there for now (original was an SVD4N60T); the plan is to swap in an FCP4N60 when the PSU more or less runs.Job for tomorrow will be to dig through the spares box and find a UC3842. For now, it's 2am and past my bedtimeCheers,Phil.
Ukrainian/Russian RLC2 RLC Meter Document Archive? - Page 1
Forum section: electronics / projects

author: Chris56000
author_rank: Frequent Contributor
timestamp: February 22, 2025, 08:08:57 pm
content: Hi!. . .Can anyone provide me with a link to the 835 MB Documentation Archive for the Russian/Ukrainian RLC2 RLC Meter please?. . .I have got the PCBs made but unfortunately the SD Card I downloaded the Archive on to has corrupted!. . .I remember the archive was named "_All Documentation for the RLC2" and was 835MB in size and contained many pictures of builds, all the Circuits, Firmware Files and Gerber's!Chris Williams

author: 8goran8
author_rank: Contributor
timestamp: February 22, 2025, 08:37:29 pm
content: Try here...https://pro-radio.online/measure/6873-1126https://www.dropbox.com/scl/fo/vzgweftiof0bcv6rdc26q/h?rlkey=k4s5q2ofer1bc9rl3mgna5z3r&e=1&dl=0

author: Chris56000
author_rank: Frequent Contributor
timestamp: February 22, 2025, 11:05:41 pm
content: . . .Thank you for that – I've downloaded a replacement copy of the archive onto my laptop – there's been another 350 MB of files added since I downloaded it last!Chris Williams
UL1569 vs UL1007 stranded wire awg22 - Page 1
Forum section: electronics / projects

author: kfc_n
author_rank: Contributor
timestamp: July 11, 2015, 08:44:43 am
content: Good day Mates!Right now I am currently confused on what type of wire should I use between UL1569 and UL1007 stranded wire AWG22. I am going to use it for stepper motor application. Any tips/comparison between the two in terms of performance, life span will do..Thanks and Regards
UL/CE certified AC/DC power supply - Page 1
Forum section: electronics / projects

author: hebnern
author_rank: Newbie
timestamp: August 14, 2013, 05:09:31 pm
content: I am working on a project that requires a PCB mount 5V 3-5W AC/DC converter. I want to get the product UL/CE certified, and was told that the cheapest and fastest route would be to find a pre-certified supply. I have found a number of options, and based on a few parameters have landed on this one:http://www.micropowerdirect.com/Pages/Product/ACDC/MPL/Prod%20ACDC%20MPL03.htmlThe one weakness that I can see is it is only EN55022 class A.Is a class B supply _required_ for a consumer product?If I wanted to make this converter class B, what filtering would be required? Just a Pi filter on the input?What would the agency approval cost implications be if I added the filtering myself versus buying a certified filter like ACFM-01 that they mention in the datasheet?Are there any other good options out there for PCB mount AC/DC converters?

author: hebnern
author_rank: Newbie
timestamp: August 16, 2013, 06:27:16 am
content: From what I have read, it is possible to go with a Class A supply for consumer equipment, but you have to add a warning stating that it might not work properly and its up to the user to take the necessary precautions. That's lame, so I'll just suck it up, and get a nice class B supply like the NFM-05-5.

author: AndyC_772
author_rank: Super Contributor
timestamp: August 16, 2013, 12:07:54 pm
content: If you want your product CE marked then you'll need to get it tested either way. The emissions from your product will depend on the other components in your design, the layout and the enclosure too, and it's certainly not the case that you can buy a CE marked power supply and then claim emissions compliance on that basis.A CE marked power supply will save you some time and effort when it comes to getting safety approval, though - but that has nothing to do with the class A / B certification.In my experience, many power supply manufacturers have trouble understanding that in order to be usable, they have to not only pass (particularly conducted) emissions on their own at full load; they have to passwith good marginsunderalloperating conditions. Without margin to spare, once their PSU is connected to a real circuit which inevitably generates some noise of its own, the complete system cannot pass an emissions test. Whilst their product may technically be legal and compliant, it's not commercially usable.

author: hebnern
author_rank: Newbie
timestamp: August 17, 2013, 07:33:24 am
content: Yeah, I understand that I will have to have it tested either way, and that there will be other factors than just the power supply. But selecting a supply that has some certification at least is a good start toward compliance. I understand that it does not guarantee compliance of the entire device though.
UL/CSA TV rating requirement for power relay? - Page 1
Forum section: electronics / projects

author: Pjotr
author_rank: Frequent Contributor
timestamp: March 13, 2015, 11:06:17 pm
content: I am not that familiar with the UL/CSA regulations in the USA/Canada. As far as I understand, power relays for switching the mains in TV sets require "TV" rating and certification: TV-3, TV-5 or TV-8, dependant on switched current. I understand that this has to do with the high inrush current and a fire hazard of tube TV sets of 40 years ago but is that still valid today?I also understand that this "TV" rating for mains relays also holds for other (household) audio and video appliances. Is this correct?

author: Pjotr
author_rank: Frequent Contributor
timestamp: March 17, 2015, 08:12:42 pm
content: No oneLet me ask the plain question then: Is it mandatory to use TV qualified relays in the US/Canada for audio and video appliances if I want to switch the mains of the PSU with a relay?Even if there is no high inrush current beyond the nominal specifications?
Ulefone uSmart connector - Page 1
Forum section: electronics / projects

author: Jorge_dPO
author_rank: Contributor
timestamp: January 14, 2023, 02:07:43 am
content: I was wondering if someone knows the pinout or how the uSmart port on the side of some ulefone phones works. I would like to do my own accesories to use this port but I cant find or know how to find what each of the contacts are. This port is used for their endoscope and microscope, so I gess is some kind of USB? I can't find 5v between any of the pins, so I'm kind of lost...The photo is from their website.Thanks in advance for any help.

author: Whales
author_rank: Super Contributor
timestamp: January 14, 2023, 08:39:41 am
content: - Perhaps it "turns on" when it detects a short or special resistance between some pins. Try measuring the accessories with a DMM?- Perhaps crack open an accessory and see if the PCB tracks make it obvious what is what?- Worst case: design an interposer so you can monitor all communications. It'll need a way of clamping between the accessory and phone.

author: Jorge_dPO
author_rank: Contributor
timestamp: January 17, 2023, 12:38:17 am
content: Quote from: Whales on January 14, 2023, 08:39:41 amThanks for the ideas, I don't have the knowledge to make the interposer, but I guess I'll buy one of the accessories and see what I can reed from it.

author: ck
author_rank: Newbie
timestamp: September 01, 2023, 04:13:50 pm
content: from top to bottomVBUSGNDD+D-(don't know)OTG (short to GND)

author: williamshane
author_rank: Newbie
timestamp: January 29, 2024, 03:26:55 am
content: Quote from: Whales on January 14, 2023, 08:39:41 amAlthough I lack the expertise to construct the interposer, I appreciate the suggestions and may purchase one accessory to see if I can glean any useful information from it.

author: Whales
author_rank: Super Contributor
timestamp: January 29, 2024, 11:30:01 am
content: ck has already revealed the magic, it's just USB.
ULn 2003 driving led strip issue, not going full off - Page 1
Forum section: electronics / projects

author: dave_j_fan
author_rank: Regular Contributor
timestamp: January 12, 2023, 06:50:47 am
content: I am driving 12led strip with arduino and ULN2003..The negative lines are buffered by uln2003.They are the segments of large 7segment display digit.The plus line are driven by MOSFET z44 and bc547 combo.IssueWhen I give high to Uln 2003 we get negatives to the segments and only selected segment glows but other segments show a faint glow.What can be the reason?

author: srb1954
author_rank: Super Contributor
timestamp: January 12, 2023, 07:10:02 am
content: Check that you have the common connection of the protection diodes is tied to +ve supply - there may be enough leakage through all the protection diodes, either DC or capacitive coupling, to cause a faint glow on unlit segments.

author: dave_j_fan
author_rank: Regular Contributor
timestamp: January 12, 2023, 09:07:52 am
content: Thank u I will check. May be long wires made capacitive coupling

author: DavidAlfa
author_rank: Super Contributor
timestamp: January 12, 2023, 09:35:49 am
content: Is -Ve = Gnd?Otherwise the Arduino "off" is still a positive voltage for the transistor gate.

author: AndyBeez
author_rank: Frequent Contributor
timestamp: January 12, 2023, 09:40:49 am
content: From your sketch, with the cathode end of the LED strips connected to the ULN2003 inverting outputs, you do not need +12V on what I asume is pin 9. Leave this pin unconnected.

author: Benta
author_rank: Super Contributor
timestamp: January 12, 2023, 05:59:31 pm
content: Does the Arduino have pull-ups on that I/O port?

author: dave_j_fan
author_rank: Regular Contributor
timestamp: January 15, 2023, 07:48:20 am
content: Yes this may be the issue. I will confirm after disconnecting

author: dave_j_fan
author_rank: Regular Contributor
timestamp: January 15, 2023, 07:49:08 am
content: arduino pullups are to be added

author: DavidAlfa
author_rank: Super Contributor
timestamp: January 16, 2023, 05:29:30 pm
content: Pullups? Why?An output is either high or low, pullups don't make sense here.
ULN Voltage reference, switchable 2-10 in 1V steps. - Page 1
Forum section: electronics / projects

author: MasterT
author_rank: Frequent Contributor
timestamp: May 13, 2024, 02:59:43 am
content: Here easy to build project, Ultra Low Noise voltage reference. Created for noise tests, mostly adc's.And test results with output set to 10V, can't say for sure what drive noise curve up at the low end, is it reference or SA input cap (been charging all day, about 50 nA leak at the moment). Data in nV/sqrt().

author: Vovk_Z
author_rank: Super Contributor
timestamp: May 13, 2024, 05:58:39 am
content: Quite simple. Thank you for sharing.
ULN2003A alternative with short circuit protection - Page 1
Forum section: electronics / projects

author: Psi
author_rank: Super Contributor
timestamp: August 12, 2013, 06:05:18 am
content: Does anyone have any IC recommendations for a 6 channel lamp driver, like a ULN2003A, but with built in short circuit protection?It needs..- 24V output operation- 6 outputs (more is ok)- 200mA+ open collector sink ability (only one channel at a time)- Built in protection from outputs shorted to 24VAny ideas?

author: David_AVD
author_rank: Super Contributor
timestamp: August 12, 2013, 06:16:11 am
content: I used a 4 channel one from On Semi (I think) a while ago. The prefix was AMIS I think. Might be other similar ones?EDIT: I think it was source only, not sink now that I think of it, but may be worth checking On Semi anyway.

author: Psi
author_rank: Super Contributor
timestamp: August 12, 2013, 06:27:07 am
content: I found the NCV7240 which does what i want but it's only available in 2k qty from digikey/mouser.
ULN2003A replacement - Page 1
Forum section: electronics / projects

author: Freighternut
author_rank: Regular Contributor
timestamp: September 21, 2011, 01:37:50 am
content: Hi,Does anybody know of a more modern replacement for the venerable ULN2003A 7 channel Darlington driver.I am starting development of a general purpose high current (500ma per channel) driver board to be driven by SPI or I2C. The board will be based on 3.3 volt logic so the driver needs to be compatible with this voltage on the input side. I will be opto isolating some channels and including a few higher current (1 - 2 Amp) outputs as well.I have spent quite a bit of time Googling for this, but have not yet found any drivers readily available.Thanks.

author: PeterG
author_rank: Frequent Contributor
timestamp: September 21, 2011, 02:38:30 am
content: Would something like this work?http://www.jaycar.com.au/productView.asp?ID=ZK8858orhttp://au.element14.com/jsp/search/browse.jsp?N=2101+204242&Ntk=gensearch&Ntt=ULN2003A&Ntx=mode+matchallpartialRegards
uLow power accelerometers with kB sized buffers - Page 1
Forum section: electronics / projects

author: itsfreerealestate
author_rank: Newbie
timestamp: December 01, 2018, 05:13:54 pm
content: I spotted that Bosch is releasing / has released a 3-axis ultra low power (single microamps in low power, ~14uA in full run) accelerometer. What seems unique about is it also includes a kB sized buffer which is something I've only really seen on IMUs. Was wondering if anyone had seen any similar accelerometers; the FIFO's on accelerometers tend to be a lot smaller.https://www.mouser.com/pdfdocs/Bosch-BMA400-flyer.pdfCheers!

author: SiliconWizard
author_rank: Super Contributor
timestamp: December 02, 2018, 02:35:58 am
content: Yes, you can take a look at AD accelerometers for instance.The ADXL372 is in the same ballpark (~22 µA, FIFO of 512 samples, higher max ODR).
Ultra Fast rotational Speed meaurement - Page 1
Forum section: electronics / projects

author: deltabravo460@gmail.com
author_rank: Newbie
timestamp: March 10, 2024, 04:26:12 pm
content: Hello, I am new to this form and seeking help designing a Tachometer to measure the rotational speed of a turbine, Max speed 450K RPM, I am thinking stroboscope is the way to go. My first thoughts are to use my wave generator (Leader LFG-1310) to drive an LED via an interface circuit. Any thoughts or suggestion?

author: Benta
author_rank: Super Contributor
timestamp: March 10, 2024, 07:30:05 pm
content: 450k rpm is just 7.5 kHz.Piece of cake.Paint 180 degrees of the output shaft black and use a reflective optodetector.Or mill two slots in the shaft and use an inductive pickup.Or...

author: PCB.Wiz
author_rank: Super Contributor
timestamp: March 10, 2024, 07:36:28 pm
content: This is likely to be small, a possible reflective opto sensor is NJL5912R at Digikey. 1.06 x 1.46 x 0.5mm

author: mjkuwp
author_rank: Unknown
timestamp: March 10, 2024, 10:03:32 pm
content: Optical interrupt sensor. use a rotor with a rotor that only blocks the LED for 1/2 the rotation angle. These sensors have an LED on one side and a phototransistor on the other. I don't know exactly if it can do that speed but i would guess so. You just need to look at the specs. of such parts

author: Benta
author_rank: Super Contributor
timestamp: March 10, 2024, 10:42:07 pm
content: Quote from: mjkuwp on March 10, 2024, 10:03:32 pm... and try balancing that mechanically/dynamically.I think the black coloring is easier.

author: Benta
author_rank: Super Contributor
timestamp: March 10, 2024, 10:46:12 pm
content: Quote from: PCB.Wiz on March 10, 2024, 07:36:28 pmGood point. The rpms indicate either an engine turbo, or a small gas turbine. On both, you'll probably need to do the measurement on the shaft end surface of the "cold" side.

author: CaptDon
author_rank: Super Contributor
timestamp: March 11, 2024, 01:52:55 pm
content: Could the O.P. elaborate on the turbine? The fastest rotating speeds of any combustion turbine or turbocharger I have ever dealt with was 100K. His turbine is over 4 X faster. It must be microscopically small? Even hydro-dynamic self centering fluid bearings are seldom rated much above 100K RPM. I'd be interested to hear why a turbine needs to spin that fast? Once blade tips exceed the speed of sound the trade offs become huge!! You can hear the buzz-saw sound of aircraft turbines when the fan blade tips are above Mach 1. They don't however remain in this mode at cruise speed.At 450K RPM even dust impinging on the turbine blades will cause erosion.

author: joeqsmith
author_rank: Super Contributor
timestamp: March 11, 2024, 03:04:15 pm
content: https://racespeconline.com/products/turbo-shaft-speed-sensorhttps://www.turbomotiv.com/product/garrett-turbocharger-speed-sensor-kit/Quote from: CaptDon on March 11, 2024, 01:52:55 pmQuotehttps://www.mahle-aftermarket.com/media/local-media-north-america/pdfs-&-thumbnails/catalogs-and-literature/turbochargers/turbo-damage-brochure-mo-2-612.pdf
Ultra low dropout LDO - Page 1
Forum section: electronics / projects

author: blueskull
author_rank: Unknown
timestamp: May 20, 2015, 10:31:27 am
content: Hi, all:Is there anyway I can get a 1.1V from 1.2V rail?Basically I want to save a buck converter, and do not want to waste a lot of energy.My topology is a 1.2V/3.3V buck, and the 1.2V goes into a FPGA, while I need another 1.1V for a DSP. I just asked ADI's FAE, they say I can not directly power it with 1.2V. So, how do I get a 1.1V out of a 1.2V source?Thanks,Bo

author: dom0
author_rank: Super Contributor
timestamp: May 20, 2015, 10:35:01 am
content: MIC61150? There are some other ultra-low dropout regulators.

author: Asmyldof
author_rank: Regular Contributor
timestamp: May 20, 2015, 11:02:39 am
content: Drop-out can be as low as 50mV depending on the current drain on reasonably well available types.You can search for that at Farnell, Mouser or DigiKey as well as most manufacturers such as TI and Micrel.Be very careful to look at the worst case scenario though, if your current use can go up to X in instances, while 1.2V could drop to 1.15V, it's likely that reduction will happen at the peak current.If your fancy LDO then defines that the 50mV drop out is at a quarter of current X, while at current X it's actually 200mV, you might find yourself hunting bugs and performance problems that could have been predicted.What actually happens a lot is creating 1.8V with buck, then LDO-ing that to both 1.2 and 1.1, since those lower voltages might also have a very tight noise budget, and the 0.5V extra headroom over the drop-out of the 1.2 regulator will give a much greater noise immunity from the buck system and such.

author: technix
author_rank: Super Contributor
timestamp: May 20, 2015, 11:03:26 am
content: Actually I would prefer using a buck switcher to derive the 1.1V rail from 3.3V or 5V rail.

author: daqq
author_rank: Super Contributor
timestamp: May 20, 2015, 11:16:08 am
content: Target current?You could add another buck regulator, there are some cheap and small ones (such as LMZ21701), or use a three output one and you can avoid all wasting any power.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: May 20, 2015, 11:24:10 am
content: How critical is either rail? Why does it matter?Most likely you can set it to 1.15 +/- 5% and satisfy both.Tim

author: Ice-Tea
author_rank: Super Contributor
timestamp: May 20, 2015, 11:56:12 am
content: FPGA? Better not mess with core voltages. Or for any digital device on a reasonably recent tech node.

author: langwadt
author_rank: Super Contributor
timestamp: May 20, 2015, 12:21:18 pm
content: Quote from: blueskull on May 20, 2015, 11:52:31 amLinear (an probably others) have some extreme low drop out regulators, they use an extra pin for a ~3.3V supplyto use a drive for the pass transistor
Ultra low leakage overvoltage protection (TVS,...) for picoampere measurements. - Page 1
Forum section: electronics / projects

author: Fabse77
author_rank: Newbie
timestamp: September 26, 2018, 09:13:04 am
content: Hi everyone,i'm building a low current measurement setup which can use voltages up to 2500 V.So I have a high voltage precision lab supply, and an electrometer like a Keithley 617 or some other pA capable SMU (see attachment). Now I need to protect the Electrometer from the high voltage if the device under test breaks down. The Keithley for example allows a max input voltages of 250V.At first I was thinking about Zener diodes or TVS, but they have all way to high leakage and because they are parallel to the electrometer they should be extremely low leakage.There is a device from Tektronix, especially made for this purpose:https://de.tek.com/datasheet/model-2290-pm-200-protection-module-users-guidewith the promising spec: Leakage: < 10 pA at 200 V typicalbut it costs around 1300 USD. And I wonder what they are using to achieve this value. The schematic on the case looks like it only uses a TVS diode.Does anyone have an idea of a protection device for Vbd~200-250 V with such low leakage current? I think a gas discharge tube should work too, but datasheets usually only say insulation resistance > 10GOhm. How good are they really?Thanks

author: Gyro
author_rank: Super Contributor
timestamp: September 26, 2018, 09:39:39 am
content: I did some experimentation with GDTs when I was building my simple Picoammeter. I found that standard 230V telecom GDTs had a leakage of several pA at10V. The ceramic ones were better than the glass ones. A 1kV ceramic one came in at about 1pA...https://www.eevblog.com/forum/projects/picoammeter-design/msg798921/#msg798921I went with making an air spark gap in the end.P.S. Welcome to the forum

author: sdouble
author_rank: Frequent Contributor
timestamp: September 26, 2018, 03:23:54 pm
content: yes, you have many option in the sub-10V range... but with 200V you are not in the same ballpark.

author: David Hess
author_rank: Super Contributor
timestamp: September 26, 2018, 03:57:59 pm
content: You might be able to do it using collector-base junctions of high voltage transistors as low leakage high voltage diodes but a gas discharge tube or even several neon bulbs in series would be a sure thing.

author: Fabse77
author_rank: Newbie
timestamp: September 27, 2018, 04:56:48 pm
content: Thanks for the feedback.I ordered some GDT from different manufacturers and will do some leakage current tests. I will share my results here when i'm done.

author: Alex Nikitin
author_rank: Super Contributor
timestamp: September 27, 2018, 05:10:35 pm
content: If you only use the electrometer for current measurements, a high voltage capable resistor in series with the input and BAV199 dual diode to ground is all you need, providing the voltage drop on the resistor is acceptable in the current range used. It would be better still if your HV supply is sensibly current limited (say, at 0.1mA).CheersAlex
Ultra-Low Profile Isolated USB DC-DC Converter - Page 1
Forum section: electronics / projects

author: Leeima
author_rank: Contributor
timestamp: October 04, 2021, 10:58:26 am
content: Hi All,I'm looking at designing a product which requires an ultra-low profile isolated usb connection - with data would be preferable but is not requiredI'd rather not use a through PCB option - which limits my vertical height to 1.8 mm which I can stretch to 2.4 mmThe smallest transformer i have found was 4mm.Does anyone have any experience of this? or possibly found smaller transformers?ThanksLiam

author: Leeima
author_rank: Contributor
timestamp: October 04, 2021, 11:14:58 am
content: Well I found a low profile part!LPR4012 only 1.1 mm tall!
Ultra Low Quiescent Current DC-DC Boost - AS1310 - Page 1
Forum section: electronics / projects

author: TheRuler8510
author_rank: Regular Contributor
timestamp: March 23, 2014, 01:37:26 am
content: Wow!!! - Ultra Low Quiescent Current (<1 uA) DC-DC Boost Part # AS1310 by AMS.Anybody ever use it or seen anything else comparable? I wish I could find a thru hole equivalent.Seems like the perfect part to use with your micro-controller that goes into (power-down) sleep mode, when on battery power.It is hard to believe there is only one type on the market.Regards,

author: Gallymimus
author_rank: Regular Contributor
timestamp: March 24, 2014, 04:53:09 am
content: This is pretty close:http://www.ti.com/product/tps61220I'd rather use name brand than a no-name.

author: mariush
author_rank: Super Contributor
timestamp: March 24, 2014, 04:57:01 am
content: That is good indeed.The best I've used was aLT1307in DIP8 package.. specs say 50uA quiescent current.

author: electrodacus
author_rank: Super Contributor
timestamp: March 24, 2014, 06:50:12 am
content: I actually use one of their DC-DC converters in my last project a Solar BMS you can find out more in the Open Source category on this forumIt dose work according to spec they are a good brand an probably the best I know of in low power and high efficiency.Texas Instruments is not even close they always have the worst products regarding energy efficiency.

author: TheRuler8510
author_rank: Regular Contributor
timestamp: March 24, 2014, 12:43:23 pm
content: Quote from: Gallymimus on March 24, 2014, 04:53:09 amDoes AMS qualify as "noname?"
Ultra sensitive hall effect sensor/switch - Page 1
Forum section: electronics / projects

author: commerou
author_rank: Contributor
timestamp: April 29, 2014, 05:52:14 pm
content: Hi thereI have just started a new project, and i need to trigger on some magnets. At the moment I am using a reed relay, but i really want to use a hall effect switch because the reed relay triggers randomly because of vibrations.The hall effect sensor needs to trip at around 0.5 mT (5 Gauss)Does anyone know of any hall effect sensors around that, I cant seem to find any?Best regardsCommerou

author: dumle29
author_rank: Regular Contributor
timestamp: June 11, 2014, 05:07:34 pm
content: Bump, I need to know this as well :SI have been looking at GMR sensors, but even these seem to not be sensitive enough.

author: mjkuwp
author_rank: Unknown
timestamp: June 11, 2014, 06:53:20 pm
content: how about thishttp://www51.honeywell.com/aero/common/documents/myaerospacecatalog-documents/Missiles-Munitions/HMC_1001-1002-1021-1022_Data_Sheet.pdfDigikey 342-1001-5-NDIt looks to require extra circuitry to get the function you desire but sensitivity is there.

author: Alexei.Polkhanov
author_rank: Frequent Contributor
timestamp: June 11, 2014, 10:54:22 pm
content: If you really need to measure small and very small magnetic field you better go with flux gate magnetometer sensors like this for example:http://www.speakesensors.com/products.htm. Hall effect sensors just not made that sensitive. these are around $50.I have feeling that for your application you should use some kind optical sensor (reflective or interrupt) instead of magnet+reed relay.Also you may notice that in many current sensors hall effect sensor is placed into a gap in magnetic core around which wire is wound to compensate for low sensitivity of hall effect sensors.
Ultra short throw beamer optics - Page 1
Forum section: electronics / projects

author: davorin
author_rank: Unknown
timestamp: September 20, 2018, 09:28:55 am
content: Again another crazy idea (o;Does someone know of a supplier which does optics for an ultra short throw beamer like the Sony LSPX-P1 or the LG PH450UG?We want to use an own TI DLP design where we just need to attach the optics and cast a user interface image to the wall...
ultra sonic reciever output - Page 1
Forum section: electronics / projects

author: navidrct
author_rank: Regular Contributor
timestamp: September 01, 2015, 10:22:09 am
content: hii give a ultra sonic transmitter a 40khz 16Vp-p .in 40 cm i capture . but in more i capture nothingwhen i put my probe in receiver pin its nothing in there .what can i do to transmit in far distance?if i increase voltage p-p will it help?how much voltage can i give ultra sonic transmitter?help me how to measure more than 4 meter with ultra sonic

author: Kleinstein
author_rank: Super Contributor
timestamp: September 01, 2015, 04:16:23 pm
content: The maximum power permited for the transducers denpends on the type. This cound be somthing like 10 to 100 volts.For the initial test the 16 v are ok, as the recieved voltage only increases linear with the driving voltage.Normaly there schould be a well detectable AC voltage at 40 cm distance - something in the 100 mV order of magnitude, so well visible on the scope. However the weather proof transducers are usually less efficient, so may give less signal - so they may need an extra amplifier.The frequency should match die transducers, some may be for other frequencies than 40 kHz.
Ultra-stable 3.3 V power supply using LT3045 and LTC6655 - Page 1
Forum section: electronics / projects

author: maxwell3e10
author_rank: Frequent Contributor
timestamp: May 31, 2021, 01:16:32 am
content: The data sheets for these chips suggest a circuit for building an ultra-stable power supply that combines the wide bandwidth low noise of LT3045 with lower 1/f noise and better temperature stability of LTC6655. But I haven't seen any documentation of their combined performance. Here are the results that more or less match the datasheets (the lowest noise level is limited by the LNA10 amplifier). For comparison, I also included the spectrum of LTZ1000 reference circuit. One can get another factor of 2 improvement at lower frequencies relative to LTC6655 by dividing LTZ1000 output by a factor of about 2 and using it as the low-frequency reference. The circuit is build by hand on an SSOP adapter. I also used ceramic capacitors to keep it small.
Ultra-thin battery? - Page 1
Forum section: electronics / projects

author: jeduffy
author_rank: Contributor
timestamp: December 21, 2019, 06:56:02 am
content: Does anyone know where I can buy cheap, very thin (<=1mm) batteries?I don't really need any significant density (a few mAh is fine). I've found a few places that make them, but no one that sells them for reasonable prices or in small quantity.Application is I'm applying for jobs the next couple months and looking to make some circuit board business cards.(can't do USB power, most companies don't allow plugging in unknown USB devices)

author: sleemanj
author_rank: Super Contributor
timestamp: December 21, 2019, 09:15:45 am
content: A cr2012 or 2016 sunken into a routed out hole of your pcb with a flat strip soldered across the bottom and a formed sort of strip soldered on top to apply contact pressure could work?NB: You might need to think about shipping issues if you intend to mail these cards, certainly no li-ion.

author: rvalente
author_rank: Frequent Contributor
timestamp: December 21, 2019, 09:43:00 am
content: Check thesehttps://youtu.be/kJXRyWQgOY4

author: I wanted a rude username
author_rank: Frequent Contributor
timestamp: December 21, 2019, 09:46:47 am
content: Quote from: sleemanj on December 21, 2019, 09:15:45 amAnd you can get CR1616/CR2016 cells with surface-mount solder tabs to make assembly even easier. The canonical example beingthe original Arduboy.

author: SiliconWizard
author_rank: Super Contributor
timestamp: December 22, 2019, 04:34:55 pm
content: Rechargeable or primary? (I suppose the latter?)

author: SiliconWizard
author_rank: Super Contributor
timestamp: December 30, 2019, 06:34:03 pm
content: Alright, the OP never bothered to answer/follow-up, but since I have some pointers, I may as well list them, if it can be useful to anyone...Primary batteries:https://www.powerstream.com/thin-primary-lithium.htmPrimary and rechargeable:https://www.pdbattery.com/ultra-thin-battery.htmlA few years ago, "solid-state" batteries started to appear, but most seem abandoned now, so I'm guessing either the technology or the market wasn't quite there...STM EFL700A39THINERGY MEC201

author: Nusa
author_rank: Super Contributor
timestamp: December 30, 2019, 06:56:06 pm
content: Another option is forget about batteries entirely and use a thin solar cell. Plenty of credit-card calculators do exactly that.
Ultra wide input AC/DC 7.5W convertor - Page 1
Forum section: electronics / projects

author: ali_asadzadeh
author_rank: Super Contributor
timestamp: December 06, 2018, 12:29:40 pm
content: Hi,I have designed several flyback converters mainly based on power Integration parts, Know for some project I need a 5V 1.5A SMPS with the input in the range of 15V-265V AC, I have seen this app note from power Integration, but unfortunately it can only deliver 3W, also searching TI website I came across this UC3843 part, and it would design it!But I want to know is the webench reliable? Do you suggest any design approach?

author: Scutarius
author_rank: Regular Contributor
timestamp: April 13, 2021, 01:10:35 pm
content: Hi!Did your power supply worked?I am curious, why did you needed that low input voltage?I am working on a similar idea, but with 25 VAC to 250 VAC, I would like to know how it worked for you.Thank you.

author: ali_asadzadeh
author_rank: Super Contributor
timestamp: April 14, 2021, 05:52:02 am
content: CesarEscudero my Idea did not work, have you made any progress?

author: strawberry
author_rank: Super Contributor
timestamp: April 14, 2021, 07:04:30 am
content: Pulse density modulation controller

author: Scutarius
author_rank: Regular Contributor
timestamp: April 19, 2021, 08:54:15 pm
content: I am actually just starting to capture the schematic, I will let you know how it goes

author: ali_asadzadeh
author_rank: Super Contributor
timestamp: April 20, 2021, 05:20:46 am
content: That would be very nice
Ultra-wide Input Power Supply - Page 1
Forum section: electronics / projects

author: steaky1212
author_rank: Regular Contributor
timestamp: July 14, 2016, 09:50:11 am
content: Hi,I was wondering any anyone could point me towards a design for an ultra-wide input power supply (or even just design ideas).I have already found details for DI-152 (https://ac-dc.power.com/design-support/reference-designs/design-examples/di-152-3-w-ultra-wide-range-input-power/) and one from TI (http://www.ti.com/lit/ug/tidu389/tidu389.pdf). These have both slightly narrower specs and different output characteristics.I currently have 3 separate power supplies, a 12-24VDC input, 24VAC/DC, and 110-230VAC input. All of these feed a 24V 12W output. I want to have a single supply that can take from 12VDC to 250VAC. Given the 2 designs above it should be close to possible, but my Google powers are failing.Any help is appreciated.Steaky

author: steaky1212
author_rank: Regular Contributor
timestamp: July 14, 2016, 02:09:05 pm
content: Right, I've stumbled across the HV9120 and HV9123 which look like they might be useful... Does anyone have experience using them?

author: zlymex
author_rank: Frequent Contributor
timestamp: July 14, 2016, 02:23:36 pm
content: I had a power adapter for Notebook PC that draw power from 12V or 220V in the same input plug. I guess there is a relay inside to make the switch.
Ultra wide input range Isolated DC-DC convertor - Page 1
Forum section: electronics / projects

author: steaky1212
author_rank: Regular Contributor
timestamp: August 13, 2013, 09:20:46 am
content: Hi,I need to design an isolated DCDC convertor with input range of 6-110V and output voltage of 12 @ 0.2A.I've used TI's Webench and didnt really get anywhere. I could probably settle to split the input voltage range into two overlapping ranges, so long as they are using the same IC and its a case of swapping a resistor value.Was anyone aware of an IC that would help in this design?Thanks in advance,

author: tom66
author_rank: Super Contributor
timestamp: August 13, 2013, 09:46:22 am
content: I've seen a TNY265 offline SMPS IC capable of going down to 6.5V input for 5V output -- not very efficient or high current, but just about doable. I'd think it would be possible using one of those ICs with an isolated topology, and a 1:2 transformer. Bear in mind your output diode is going to need rating to around 400V.

author: Marco
author_rank: Super Contributor
timestamp: August 13, 2013, 06:24:33 pm
content: What's wrong with a basic UC3842 circuit with external MOSFET switch and a flyback transformer with an auxiliary winding? (Simplified circuit shown in figure 7here.) Regulating the voltage from the auxiliary creates power for the IC as well as allowing you to regulate the output voltage without an optocoupler or primary side sensing (which due to the high voltage on the primary would require extra circuitry).The resistor bootstrap won't work because of the large input voltage range (unless you want to burn a couple Watts in the resistor at 110 Volt). A resistor/zener/mosfet bootstrap will work though, just have it create a lower voltage than the regulated voltage of the auxiliary, so the MOSFET gets turned off once the circuit gets going.Duty cycles will be very short at 110 volt and switching losses rather high of course.
Ultra-WideBand Feather for Localization projects - Page 1
Forum section: electronics / projects

author: jedhodson
author_rank: Newbie
timestamp: January 01, 2020, 06:41:17 am
content: As part of a larger robotics project, I required a system for low range localization and came across the Decawave DWM1000 module. A little work has been done on it in the community before but many of them seem to have turned commercial and the price wasn't exactly appealing. So I made my own.The Ultra-WideBand Feather incorporates the Decawave DWM1000 module and an ATSAMD21 ARM Cortex M0 into the Adafruit feather form-factor. The DWM1000 module is an IEEE802.15.4-2011 UWB compliant wireless module capable of precision indoor positioning and high data rates, making this board perfect for robotics projects where localization is required. The feather form-factor makes it easy to implement into projects. I'll be using these as the Anchors for a larger project.There were some minor design issues that I've listed to be changed on the next revision. Primarily the fact that I used the wrong footprint for the USB connector but all was well because I had the SWD header. Overall I was pretty happy with the results considering it was my first full PCB designed project that had more than a handful of components.Full write-up is on my website atprototypingcorner.io/projects/uwb-feather?utm_source=eevblogJed Hodson