hybridfree/eevblog-posts huggingface dataset:
A flexible tool set for production programming and firmware / file manipulation - Page 1
Forum section: electronics / projects

author: Phantomix
author_rank: Contributor
timestamp: June 01, 2014, 04:12:06 pm
content: Hello everyone.Over the last few weeks, I was busy programming a small tool set that allows me to manipulate firmware files and then flash them on microcontrollers. The preliminary name for it is FirmwareBatchTools.http://firmwarebatchtools.ugfx.org/The idea behind it is to have a self-definable "task list" that one can run multiple times, over and over again. The GUI version allows to create this list and store it into an xml file. In the main window, you can then run it with one click.The supported task types are (by now): Load (firmware) file from disk, Save file to disk, Create a serial number, Run external program, Define a variable, Read and Write variable.Internally, two more concepts are important to fully understand the operation:- RAM representation of the firmwareYou may load a firmware (e.g. a .hex file) into RAM. The file is parsed and held in a dynamic buffer for later manipulation.- VariablesI integrated an easy, yet powerful variable system which lets you define variables (e.g. a serial number), do calculations, read and write from/to the RAM.As file types, I currently support binary and Intel Hex files. I also plan to support Motorola S19 and maybe OH51, ELF later, while OH51/ELF are bit of a problem, if I want to preserve the metadata like symbol names.The licensing is currently bit of a problem, so I cut it down to a "non-commercial use" until I've got a reason to change this ;-)What do you think about this? Could it be useful to you or what would you like to see in a future version?

author: zapta
author_rank: Super Contributor
timestamp: June 01, 2014, 04:31:10 pm
content: Looks very nice. I am using she'll scripts. Ant/Antelope could be a good starting point. Does it runs on Mac OSX?Sent from my Nexus 5 using Tapatalk

author: Phantomix
author_rank: Contributor
timestamp: June 01, 2014, 04:41:01 pm
content: Hello,It's a Windows .NET 3.5 (C#) application.Maybe (also: if I have a good reason), I could imagine moving everything to QT (C++) but this would be work for a couple of weeks again ;-)How could Ant/Antelope help me?

author: theatrus
author_rank: Frequent Contributor
timestamp: June 01, 2014, 04:55:36 pm
content: It's standard UNIX practice to make a single tool and combine them via scripting, as opposed to a monolithic tool. You can then use various other tools (shell scripts, ant, etc) to combine them for your application.Functionality looks very similar to an internal tool I made a long time ago in Python.

author: Phantomix
author_rank: Contributor
timestamp: June 01, 2014, 05:13:47 pm
content: Well, you're partially right. But having this split up in small tools would ruin the benefits of a combined tool (e.g. support for file types or the everywhere present internal variable system).You may however use this as a command line tool (FirmwareBatchConsole.exe) to include it into scripts etc.
A flight control board shield based on arduino - Page 1
Forum section: electronics / projects

author: dreamtale
author_rank: Newbie
timestamp: November 19, 2014, 03:04:54 am
content: I designed a shield,can be directly plugded into the arduino.Above it contains a complete gesture systems.such as MPU6050,HMC5883 and some other modules.Long time ago, I just want to design a shield contains many sensors, which can achieve a lot of features. I realizedAfter a modification over time, I sent my gerber files toSmart Prototypingand production. I changed a lot, I was going to use PCF2129 replacement DS1307, but PCF2129 is expensive so I had to give up.I also modified schematic.I had made a serious mistake, because avr328 output is 5V, but many modules work in 3.3V. If the direct connection, it may cause some unexpected problems. In the end, I had to drastically modify my schematic.I use the relevant characteristics of the NMOS.I made a simple level conversion circuit to make sure the system compatible with 5V and 3.3V.In addition, according to the recommendation of some friends, I added MPU6050 as an acceleration sensor and an acceleration sensor. Now I have a complete PCB board 9-axis motion chip, it can know your stance and direction.Many times, some projects need to use an SD card to store some parameters or some other data, I integrated the MicroSD card on the shield,I also set up a separate power jumper cap for each module, so that you can turn off some of the features when you does not require the use of certain modules.If someone has some good suggestions, I would be happy to improve my shield

author: dreamtale
author_rank: Newbie
timestamp: November 28, 2014, 01:50:51 am
content: Because of my mistake, I had to buy a new soldering paste to complete.

author: ivan747
author_rank: Super Contributor
timestamp: November 28, 2014, 02:54:24 am
content: Because of the QFN?check outhttps://www.eevblog.com/forum/projects/is-this-board-solderable/

author: dreamtale
author_rank: Newbie
timestamp: December 03, 2014, 07:40:35 am
content: Maybe,Paste exposed to air for too long, and I think it lost activity.
A fusible wirewound resistor maximum watt determination - Page 1
Forum section: electronics / projects

author: abdulbadii
author_rank: Frequent Contributor
timestamp: August 14, 2022, 02:21:52 am
content: How do we know/determine a fusible wirewound resistor maximum power (start from the most common or simplest test or tool) ?

author: Conrad Hoffman
author_rank: Super Contributor
timestamp: August 14, 2022, 03:05:30 am
content: Are we talking continuous power or pulses? Ohmite had a paper on pulse power and the numbers were extremely high. For continuous, I'd think you'd choose an operating temperature, cooling conditions and such, then just see how much power it took to achieve it. I'm sure the manufacturers run large numbers of parts and collect statistical data to be sure they're shipping to whatever quality level they need.

author: Psi
author_rank: Super Contributor
timestamp: August 14, 2022, 03:09:26 am
content: probably destructive testing

author: floobydust
author_rank: Super Contributor
timestamp: August 14, 2022, 09:48:13 pm
content: Quote from: abdulbadii on August 14, 2022, 02:21:52 amIt's in the datasheet and UL 1412
A good place to buy Hakko parts? - Page 1
Forum section: electronics / projects

author: toli
author_rank: Frequent Contributor
timestamp: September 03, 2010, 05:48:14 pm
content: Hi guys,I've picked up a used Hakko 470 desoldering unit yesterday. It wasn't in the best shape, but the price was very good, and it was a local guy so no shipping or tax to worry about. So I've purchased it. I've tested it, and the pump works, the filters are just fine, and the heater works which means the base unit is in good shape. I've also used it on a few solder joints on a board I've had lying around, and it worked just fineThere are only 2 issues with it. The first is it needs a new nozzle, the second is the I should probably get a new heater as well. While the one in there works, the shaft at the end is damaged and I'm worried it might not have a complete seal in this state.I want to buy these two parts. So far I've sent an email to tequipment (got no response yet). They have the parts on their site, just want to make sure they have them in stock or at least can get them in a reasonable time. I'll also go to the local Hakko representative over here in Israel on Monday. Is there some place else I can check for these parts? The part numbers are A1029 and A1003.BTW, I checked on ebay. Its quite expensive to get the parts there.Thank you.

author: DJPhil
author_rank: Frequent Contributor
timestamp: September 03, 2010, 11:25:04 pm
content: I'm not sure where you are, but if you're in the US I'd suggest AllSpec. I've picked up all my soldering stuff from them and they've treated me well when I've asked a bunch of questions.Here's their links for your parts:A1029A1003You might be able to shave a little off of that price, but it's about what I'd expect. AllSpec is very careful to deal directly with Hakko, so you're getting the good parts.Hope that helps.

author: toli
author_rank: Frequent Contributor
timestamp: September 04, 2010, 06:17:09 am
content: Thank you for the link. As I've stated in the first post, I'm from Israel.tequipment and all-spec have exactly the same price for both items. I'll see how much shipping to Israel will cost, and perhaps just send it to my family in the states and have them send it over here if the store won't ship here directly.
A good Tech reference for components - Page 1
Forum section: electronics / projects

author: Geoff
author_rank: Contributor
timestamp: January 12, 2021, 04:12:57 pm
content: Do you know of a good technical reference for components?Something detailed that covers the new types of components, that my 30+ year old book on the subject does not know about. eg Aluminum Polymer Capacitors.When looking for the best 220uF cap for a design that needs to be long life, in a temperatures up to 70C. I spotted "Aluminum Polymer Capacitors" which is new to me. Now I am thinking what else is out there. And while the follow blog is informative it would be good to have a current overview of component types:https://www.we-online.com/web/en/electronic_components/news_pbs/blog_pbcm/blog_detail-worldofelectronics_105536.php

author: bob91343
author_rank: Super Contributor
timestamp: January 12, 2021, 07:39:12 pm
content: Most books are obsolescent by the time they get published. Times change so quickly that the best sources for this information are probably the manufacturers themselves. Of course never just one manufacturer, to keep it unbiased.Many innovations arise from necessity. A capacitor company needs, to stay competitive, to do almost basic research on materials and applications. Reputation hinges on every product. Legacy products never completely go away, and new products need years to prove themselves.I know that avoids answering your question but that's because I don't know the answer.
A grip strength measuring device. - Page 1
Forum section: electronics / projects

author: Hextejas
author_rank: Frequent Contributor
timestamp: June 30, 2022, 03:00:22 pm
content: Has anyone seen a grip strength measuring device ? My wife recently had a small stroke and her left hand is a lot weaker than her right. I was hoping that there might be something that I can build using maybe a Raspberry Pi. The 1st hurdle would be as to what to use on her hands. Gloves are ideal but they sound impossible. Maybe something like a bicycle brake ?Thoughts ?thanks,

author: jpanhalt
author_rank: Super Contributor
timestamp: June 30, 2022, 03:12:52 pm
content: Have you searched for grip strength dynamometer? Several on Amazon for < $50

author: moffy
author_rank: Super Contributor
timestamp: June 30, 2022, 03:14:12 pm
content: Sorry to hear about your wife, perhaps this would be suitable:https://www.ebay.com/itm/203442128085?hash=item2f5e1884d5:g:~vwAAOSwAfJgkTXjkind regards to your better half.

author: tszaboo
author_rank: Super Contributor
timestamp: June 30, 2022, 04:29:41 pm
content: You can measure grip strength with an old bathroom (weight) scale, no fancy devices needed.Good luck with the recovery.

author: MikeK
author_rank: Super Contributor
timestamp: June 30, 2022, 07:33:10 pm
content: I used a grip strength measuring device in physical therapy after breaking my hand. Ask your healthcare provider?
A "high-end" 858D desoldering station - Page 1
Forum section: electronics / projects

author: mosafet
author_rank: Contributor
timestamp: January 30, 2019, 01:49:29 pm
content: The "cheap crap" 858D+ design seems really good to me. Yes, they're almost all (all?) made of Chinesium and a fire hazard. HOWEVER... What would happen if someone built an 858D clone with real, brand-name, parts? With real firmware, all the safety sensing and such. I think it's a really good clever design that only lacks some polish. Something in the $100US range.I own the Weller. I own the Quick. I own several 858 clones. I compare them all. The 858 in terms of price versus performance is king! This design is elegant and price effective. They just need to use better quality parts and firmware. Then it would beat the best.Yes, the Weller and Quick are faster in absolute terms but they're using actual 700+W/1000W elements whereas the Chinese parts are using 500W/600W parts probably due to safety design concerns. All things being equal I think the 858 design would destroy everything else.Am I missing something?

author: 001
author_rank: Super Contributor
timestamp: January 30, 2019, 03:32:25 pm
content: Quote from: mosafet on January 30, 2019, 01:49:29 pmWhat is for "with real, brand-name, parts? With real firmware"? Try some russian via google translate featurehttps://radiokot.ru/lab/controller/10/https://radiokot.ru/lab/controller/69/Russians like 1602 displays at ironshttps://www.radiokot.ru/forum/viewtopic.php?t=2016

author: KL27x
author_rank: Super Contributor
timestamp: January 30, 2019, 06:49:32 pm
content: QuoteYes, indeed, you are. You seem to be missing brand loyalty, susceptibility to peer pressure, confirmation bias, and innate disdain for chinese imports. I bet you don't even use terms like "one hung lo."

author: GreyWoolfe
author_rank: Unknown
timestamp: January 31, 2019, 01:23:18 am
content: Quote from: mosafet on January 30, 2019, 01:49:29 pmYou already have an 858D with quality parts, the Quick, I assume the 957DW? I have the Quick 957DW and a Yihua 858D. I am going to find someone local to give the Yihua to as it is just sitting on the shelf gathering dust. The Quick is so much nicer, even with the somewhat stiff hose.I doubt the Chinese units are using 500W/600W instead of larger elements for safety concerns. I have seen the inside of both my units. No comparison. An 858D with a 700+W heater would probably be a real fire starter. At lease, my Yihua was wired correctly and didn't need fixed.

author: Shock
author_rank: Super Contributor
timestamp: January 31, 2019, 08:04:58 am
content: Quote from: mosafet on January 30, 2019, 01:49:29 pmThere is already custom firmware and a replacement board someone posted. Rolling your own PCB using the open firmware is just a matter of putting in the time and effort. The problem with replacing the handle is it will drive up the cost to several hundred dollars. Should be able to keep it around $30 with a repurposed transformer, PCB, microcontroller, misc components etc.https://www.eevblog.com/forum/reviews/youyue-858d-some-reverse-engineering-custom-firmware/
a high side load switch made from n channel and p channel mosfet working princip - Page 1
Forum section: electronics / projects

author: oppel
author_rank: Newbie
timestamp: April 29, 2024, 08:41:30 am
content: Hello, I did research on the internet to understand the working principle of the circuit you see in the image, but I could not find an article that explains exactly how the N-channel and P-channel MOSFETs used here work according to their transmission cut-off states. I would appreciate it if you could give detailed information about the working principle of this circuit.

author: moffy
author_rank: Super Contributor
timestamp: April 29, 2024, 09:18:48 am
content: When 'enable' is low then Q1 is 'off', and the gate of Q2 is pulled up to its source by R2 and it too is 'off'. When 'enable' is high then Q1 is 'on' and the gate of Q2 is pulled down to 0V turning Q2 'on'.

author: BennoG
author_rank: Frequent Contributor
timestamp: April 29, 2024, 09:43:17 am
content: This type of driver will only work up to about 20V, above that you need extra protection to not go above the maximum Vgs value.Benno

author: Terry Bites
author_rank: Super Contributor
timestamp: April 29, 2024, 01:51:30 pm
content: For higher voltages, you can split R2 to keep Vgs to a safe level.

author: BennoG
author_rank: Frequent Contributor
timestamp: April 29, 2024, 02:23:33 pm
content: Yes that is a possibility, myne had to work from 12V to 50V, so that made it a little more complex.Benno

author: Doctorandus_P
author_rank: Super Contributor
timestamp: April 29, 2024, 03:27:41 pm
content: Quote from: BennoG on April 29, 2024, 02:23:33 pmMeh, replace R2a in the previous schematic with a TVS diode, or better, add a TVS diode to limit the maximum gate voltage, but leave the resistor so it will firmly turn the FET off when it should be off.Circuits like this switch quite slowly, because of the combination of resistors with the gate capacitance. This is OK for switching loads occasionally (such as also done with Relays), but if you want to switch loads fast (such as with PWM) then this slow switching may cause a lot of trouble and the FET is likely to let out it's magic smoke and die in a puff or a loud bang.

author: temperance
author_rank: Super Contributor
timestamp: April 29, 2024, 04:47:37 pm
content: This is how I do that.The base drive voltage together with the emitter resistor form a current sink. (Udrive-0.7V)/ R1Select R2 such that the voltage across R2 never exceeds the maximum gate source voltage for M1.You can adjust the turn on speed with C1 (Miller integrator) to prevent high current surges if the load is capacitive.You can add a diode in series with C1 if only the turn on speed should be adjusted.

author: HwAoRrDk
author_rank: Super Contributor
timestamp: April 30, 2024, 02:08:10 am
content: It should also be noted that R3 in OP's schematic is of minor relevance to the switching functionality. It could be removed.It only serves to add a small constant load to the output, and will also (slowly) discharge the output when Q2 is switched off.
A high-speed PCB Routing service? - Page 1
Forum section: electronics / projects

author: coldfiremc
author_rank: Regular Contributor
timestamp: September 21, 2021, 08:35:36 pm
content: HiI need to route a board for a project with some high speed stuff (125msps ADC, FPGA, fancy connectors, Clock generators, Signals coming from coaxial links) and considering that I'm also making firmware and software tasks, doing this by myself is too much work, so I'm looking for a PCB routing service that can handle this kind of design.Can you suggest websites/firms that do this kind of service? It can be almost anywhere (China, States, Europe). There's some budget available, but not unlimited of course.Thanks
A little confused about the LM5085 inductor esr - Page 1
Forum section: electronics / projects

author: Simon
author_rank: Unknown
timestamp: April 23, 2023, 07:35:04 pm
content: https://www.ti.com/lit/ds/symlink/lm5085-q1.pdfPage 13, equation 13 leaves me a little confused. If by inductor esr they mean the DC resistance this requires quite some loss and I won't even find such a silly inductor. As we are talking about the in cycle behaviour we are hardly talking about the impedance due to frequency.I am a little stumped, I am used to looking at the time it takes the current to ramp to the peak current during the expected on time and the inductor should be such that it limits this ramp. This seems to be taken care of as I would expect in formula 18 on page 20.Is there something I missed, or is the explanation a bit all over the place?
A little help finding a board camera: SC1020 - Page 1
Forum section: electronics / projects

author: IdahoMan
author_rank: Regular Contributor
timestamp: November 11, 2017, 03:54:14 am
content: Always looking for good, affordable (NV/Thermal is still monetarily banned) low-light camera/imaging tech. I even started a Thread about it on another forum,here.A fellow there named "nonoze" has contributed a lot of testing and the best camera found so far is the "SC1020" board camera.The thing is, and he talks about it down the page, it seems very difficult to find a seller. He was lucky to get his. So a couple of goals for this Thread:I. Where/how can one purchase the SC1020II. Talk aboutaffordablelow-light techThank you.IM

author: ChrisLX200
author_rank: Unknown
timestamp: November 11, 2017, 10:00:05 am
content: What price would you call 'affordable'? Low Light cameras usually need to be cooled to reduce noise but a DIY approach is possible for that, either passive or using a TEC. You expecting to capture video or single frame? What about size/weight? At one extreme is the Moravian G4-16000 which I own, at the other modified webcams..PS. The G4-16000 can do this:

author: IdahoMan
author_rank: Regular Contributor
timestamp: November 12, 2017, 05:40:25 am
content: In order to be useful it would have to be video that can capture movement without blurring badly.
A Little Project of Mine: Some Digital Synthesis  - Page 1
Forum section: electronics / projects

author: madshaman
author_rank: Frequent Contributor
timestamp: May 11, 2014, 05:56:26 am
content: I realised I haven't really shared much on the forum in the way of what I'm working on, but I do ask a lot of questions.Here's a little board I'm working on, which for the first stage will generate 4 channels of  up to 100Khz arbitrary waveform generation. I'm not super experienced in this so I'm quite happy with the result I've obtained.This shows (on the DSO6034) the output of 4-pins on an Atmel 8-bit uC (with a whopping 2K of RAM) running at 16Mhz: The 4-bit output is the waveform of one channel and is "dithered" to increase effective vertical resolution at the cost of bandwidth (I'm outputting to the four channels (which involves writing to 3 separate ports unfortunately) at something like 1.3Msps; I'm not using interrupts, but instead have an infinite loop written in assembly that runs flat out). The reason the final bandwidth is yet to be determined is that I have to include instructions in that loop which handle communication with the uC, the final bandwidth will depend directly on how well I can optimise the code; I also have the option of increasing the clock rate to 20Mhz within spec.The output of the data pins are directly connected to an R2R ladder and then filtered by a cap to ground.On the analog scope you can see the unfiltered result which has a close-up showing the dithering (zoom of the highlighted part of the waveform) and also the filtered result which looks quite nice.Right now this is all on a 3M solderless breadboard, so my next steps are to solder up a board, put it in a shielded box and look at the harmonics on my DSA (and from there try to reduce harmonic distortion). I can post pictures of this if anyone would be interested.
A little RF help needed ( bluetooth transmitter ) - Page 1
Forum section: electronics / projects

author: peterr
author_rank: Newbie
timestamp: April 20, 2022, 03:28:51 pm
content: Hi,I'd really appreciate a little help with this as I know very little about RF stuff.I have a Bluetooth transmitter that has a PCB trace antenna. I'd like to adapt it to using an external antenna. Fortunately the PCB has unpopulated pads for a U.Fl surface mount antenna socket so much of the work is done after I solder on a suitable socket.The output path from the Bluetooth chipset ( CSR8670 ) goes through a bluetooth bandpass filter and then splits two ways via three pads. Two of the pads have an inductor in place which then goes to the printed antenna and a capacitor. The other path ( currently disconnected ) seems to be designed to use an inductor via the currently unpopulated pad and the other pad shared with the common path, The attached photo shows the arrangement with the broken path illustrated with a red line.I looked at the CSR8670 datasheet for assistance with values for a suitable LC network on the alternative path but the datasheet doesn't give any help other than indicating that an LC network is not required.So I could just solder a U.Fl socket, remove the existing inductor ( L4 ), bridge the pads across the red line and it should work if I'm reading the datasheet correctly.Or should I populate the path to the U.Fl socket with an inductor and capacitor. And if so, what values would I be looking at?Thanks.

author: Terry Bites
author_rank: Super Contributor
timestamp: April 20, 2022, 04:04:12 pm
content: I cant claim to have the Voodoo, but how about a scalpel and phone app that measures the signal strength to get started?https://www.lairdconnect.com/resources/white-papers/antenna-matching-within-enclosure

author: virtualparticles
author_rank: Regular Contributor
timestamp: April 25, 2022, 03:48:23 pm
content: The datasheet claims that the PA output is 50 ohms, so you should be able to remove the connection to the left and bridge the connection to the connector with a piece of wire. Keep the cable from the UFL connector to the antenna short. The kinds of cables which fit this size connector are quite lossy.
A Look-Ahead Clock Gating Based on Auto-Gated Flip-Flops - Page 1
Forum section: electronics / projects

author: promach
author_rank: Frequent Contributor
timestamp: November 14, 2020, 02:12:10 am
content: In figure 6 of Shmuel Wimer’s paper :A Look-Ahead Clock Gating Based on Auto-Gated Flip-Flops, negedge-triggered FF''' does not justify the need for negation bubble after X''' output ?
A Lowpass filter change, dodgy or.... - Page 1
Forum section: electronics / projects

author: Mark19960
author_rank: Regular Contributor
timestamp: December 13, 2020, 04:25:28 pm
content: Trying to work out the purpose of a change that is being made to a Sallen-Key LPF...Consider the following circuit...The modification to this filter is to change R6 to 33k and R7 to 50 Ohms...... Yeah.....The observed effect is that it passes frequencies from ~150Hz thru to ~5.2Khz after these two values are changed.That is their desired effect.But why would someone do that instead of change, for example, C3,C4,R3, and R4 and the equivalent components in the second stage?I guess I am trying to rationalise whether or not this is a case of ignorance on fire or just someone being lazy?I can throw the .asc up if anyone wants to fiddle.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: December 13, 2020, 06:28:15 pm
content: Well, could be. What are those R+Cs doing on the output? Nothing, unless it's a specific amp type. It's not labeled, so I have no idea.Source doesn't say DC bias so the sim is expected to give nonsense.Tim

author: Mark19960
author_rank: Regular Contributor
timestamp: December 13, 2020, 07:29:27 pm
content: Sorry. I had 'make this information visible' unticked. I have it at 1V.That said, the result looks right to me.As to the other resistors and caps at the output.... those elements are switched in and out depending on the mode.They don't make very much difference overall. I could have simply not put those in.

author: srb1954
author_rank: Super Contributor
timestamp: December 13, 2020, 09:45:44 pm
content: Quote from: Mark19960 on December 13, 2020, 04:25:28 pmI would opt mostly for ignorance, with perhaps a small dash of laziness, as the reason for these changes.Changing R6 would degrade the roll-off performance of the original design of the LPF filter rather than just shifting the cut-off frequency. To shift the cut-off frequency all resistors or all capacitors around the op amps need to be scaled by the same ratio.The change to R7 was probably just to increase the output level but it has inadvertently shifted the HPF filter cut-off frequency much higher. The series output cap C1 should have been increased by a factor of 3 to maintain the same HPF cut-off frequency.The other series RC networks from the op amp output to ground will do essentially nothing with a normal op amp.
A mosfet switch for my power supply output - Page 1
Forum section: electronics / projects

author: nukie
author_rank: Frequent Contributor
timestamp: January 17, 2021, 05:59:03 am
content: I have a HP E3610A power supply that I use for more than 16 years now. While it is a very nice and simple linear power supply it is also lacking of the output switch. My other power supplies has an output switch, which either triggers a relay or a discrete semi switch or some sort.I am thinking of addding a low ohm logic level mosfet in between the PS and the load. I will be powering the mosfet with a CR2032 and a toggle switch, it has an on resistance of 16mOhm at 1.8V. So I am wondering what's the implications of such mod which I should be aware of?

author: ledtester
author_rank: Super Contributor
timestamp: January 17, 2021, 08:20:25 am
content: Why not just use the switch itself?QuoteAn immediate thought that comes to mind is that a CR2032 won't last you for another 16 years. As it depletes some of your circuits will stop working but others will work just fine. You'll spend a lot of time and frustration trying to figure out what's going on. You might spend a lot of thinking the problem is with your power supply, replacing caps, transistors, op amps. Eventually the power supply will quit working altogether even though all of the components test good. You'll wonder why you ever took up electronics as a hobby in the first place. It might drive you to insanity.

author: nukie
author_rank: Frequent Contributor
timestamp: January 17, 2021, 11:27:03 am
content: Quote from: ledtester on January 17, 2021, 08:20:25 amI don't think it's easy to find the custom? mechanical switch in Australia. Plus the mains toggle switch powers down the whole unit and it also takes quite a bit of pressure to push.

author: jonpaul
author_rank: Super Contributor
timestamp: January 17, 2021, 12:43:23 pm
content: consider capacitive and inductive loads energy storage.Use the button or put a digitally controlled relay in series with mains.Perhaps $10DoneJon
A new Ceramic Capacitor Piezoelectric Effect. - Page 1
Forum section: electronics / projects

author: montcler
author_rank: Contributor
timestamp: May 23, 2017, 06:24:13 pm
content: Hello all,A few days ago I was given a circuit board that I developed to control a 900W motor PWM, this circuit board works with the A3941 Allegro driver. My surprise was when I started the engine, everything worked but there was a background sound.Checking the whole circuit board until finding the sound as it spread all over the circuit board, at the end were CBoot capacitors, these capacitors are 1.5uF 50V (Ref digikey: 445-12701-1-ND) I realized that they are Of the CGA series, it may be that this influences.The capacitors are near the driver as indicated by the datasheet.I could do it so they would not make so much noise.Here are some pictures attached.THX.Here are some pictures attached.

author: w2aew
author_rank: Super Contributor
timestamp: May 23, 2017, 06:38:02 pm
content: It's possible that your PWM frequency happens to hit a mechanical/acoustic resonance of the caps and board. Are you able to experiment with changing the PWM frequency to see if the volume of the sound changes (moves away from a resonant point)?

author: tautech
author_rank: Super Contributor
timestamp: May 23, 2017, 07:56:37 pm
content: Watch this vid for some addition understanding of cap behaviour:https://www.eevblog.com/forum/chat/capacitors-explained-by-james-lewis-of-kemet/

author: montcler
author_rank: Contributor
timestamp: May 23, 2017, 08:56:36 pm
content: Hi,I have been changing the frequency of PWM (50hz, 100hz) and seems to put less attenuates enough but still heard whisper.The PWM frequency of the motor is between 15Khz to 20khZ.I have seen in digikey different series of capacitors ... C, CC, CL, GRM, CGA etc ...It is not possible that switching to another series does not make noise ..THX.

author: Audioguru
author_rank: Super Contributor
timestamp: May 24, 2017, 01:18:49 am
content: Film capacitors are used in audio circuits because they are not microphonic like ceramic capacitors.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: May 24, 2017, 04:05:29 am
content: Bootstrap capacitors are unlikely to produce much sound, because the ripple voltage should be small. This may give you some clue what to do, if they aren't.It is true, the Piezoelectric effect is symmetrical, so that mechanical strain induces voltage, and vice versa.Inductors often produce sound as well, for analogous reasons, though this time the effect is magnetostriction, which doesn't lead to as much microphonic behavior because it is a square-law effect.Tim

author: montcler
author_rank: Contributor
timestamp: May 24, 2017, 06:51:53 pm
content: Hi,I'll do more tests and see what happens. Any recommendation...?THX.
A new wrinkle in ion sources? - Page 1
Forum section: electronics / projects

author: ikrase
author_rank: Regular Contributor
timestamp: February 03, 2018, 05:59:50 am
content: Electron impact ion sources used in mass spectrometry usually seem to fire the electrons sideways (sometimes in a magnetic field) and homemade ion sources usually fire the electrons in the same direction the ions are going which has... problems.However, it seems to me like a good option would be to have the cathode also be an extraction electrode -- electrons would fly opposite the direction of the ion flow, and space would be saved. There would be no need for a "hump" to catch / redirect electrons, and the trap and repulsor would be the same electrode.Does anybody have any thoughts on this or why it is not more frequently done?

author: John Heath
author_rank: Frequent Contributor
timestamp: February 03, 2018, 03:40:34 pm
content: Old TVs from the early 1950s had a electron forward , ion forward both in the same direction. In there case it was not to generate ions rather a problem that it is generating ions. The big heavy ion would accelerate in the electron gun then bash the delicate phosphor coating. This would lead to a brown spot in the middle of the screen called phosphor burn. Head will roll in the stock holders meeting if something is not done about these unwelcome ions. There solution was an ion trap. The first stage of the electron accelerator was tilted off center by 20 degrees. A magnet was then used to redirect the electrons back in the forward trajectory. The big fat ions were too heavy to make this turn so they ended up hitting the neck of the picture tube. There are many old farts in this group like myself who have a clear memory of adjusting the ion trap on old TVs.This being said the same ion trap could be used in the opposite way to trap electrons and free ions for mass spectrum measurement.
a nice modified \ pure sine wave inverter from ebay \ aliexpress for 50$. - Page 1
Forum section: electronics / projects

author: xReM1x
author_rank: Regular Contributor
timestamp: September 16, 2015, 05:46:26 pm
content: does anybody know or have any suggestion for a good sine wave inverter (modified sw is fine, it is going to be used on lamps and chargers..)the RMS wattage needs to be about 500-1200W. I know I cant get a brand name high quality one for 50$ but it is just for fun basically.ebay is very recommend. I cant get from amazon.
A odd one, low amp cooling of a welder. - Page 1
Forum section: electronics / projects

author: .RC.
author_rank: Frequent Contributor
timestamp: July 18, 2024, 07:09:29 am
content: I have a bit of an odd one here and am looking for ideas.I have an old generator with auto idle. I have an older mains powered transformer mig welder (no microprocessor anywhere in it). What I would like to do is make the generator go to auto idle when the mig welder is not welding.I can get the engine/generator to auto idle by simply disconnecting the cooling fan. The welder has a 240V cooling fan that runs all the time on it.The welder has a small transformer on it that outputs 24V, 36V and 110V all AC. I have connected a 24V computer fan to it via a bridge rectifier and it will run and the engine will auto idle as the computer fan must draw so little current of course they slow down when the engine is at idle.The welder also has a thermal cutout mounted on the welder diode rectifier so if the diodes get too hot it should cut power to the wire feeder.My plan was to connect two computer fans via a bridge rectifier to cool the welder rectifier diodes. Also add a 70 degree?? thermal switch to the welder rectifier connected to the main fan, so should it get that hot the main fan would cut in.Can you run three 12V fans in series off a rectified and smoothed 24V AC supply (so you get around 34VDC.)Anyone have any other ideas?

author: Phil1977
author_rank: Frequent Contributor
timestamp: July 18, 2024, 07:43:15 am
content: It´s definitely better to use a small DC DC from the smoothed transformer output.Computer fans are usually brushless, that means they have a lot of logic between their DC input and their motor windings. These drivers want stable input voltage, and if you put them in series this is not stable at all.Beside that it seems perfect to just use a thermostat for the main fan. So the generator stays only active if the welder got hot - and in this case it´s probably also good for the generator to run a few minutes longer.

author: .RC.
author_rank: Frequent Contributor
timestamp: July 18, 2024, 08:03:03 am
content: Thanks, I did try a buck converter, but the generator saw that as a load and would not idle down.My other idea was install some computer fans, but power them by a power tool battery.

author: Phil1977
author_rank: Frequent Contributor
timestamp: July 18, 2024, 08:25:55 am
content: Did you try to underpower the fans by reducing the output voltage of the buck converter? Did you use a buck with low idle power?You could also charge some supercaps while welding and feed the fans with them.
A Power Amplifier from DC to 1MHz with output  120Vp-p@8A - Page 1
Forum section: electronics / projects

author: ingenuwork
author_rank: Newbie
timestamp: August 09, 2023, 07:49:34 am
content: I am building a instrument to measure a power-loss of magnetic core of the inductor, then I found that audio power amplifier can only go to 20kHz. but the inductors need be excited in 20kHz~1MHz with voltage up to 800Vp-p and current up to 50Ap-p. So I spent 2 years to design and make a satisfactorily AMP.Here I post what I had done step by step.The Version 1:the first AMP I do is use Power Stage of a OPA. I selected OPA637 as the front stage to drive a NPN+PNP pair transistors, I think it's a Emit follower:Then the NPN+PNP pair transistors drive a P-MOSFET on the positive side and a N-MOSFET on the nagetive side through a resistor which is connect to the Collector of transistors .the version 1 amplifier achieved to 500kHz 80Vp-p@8A，but frequency can not go more higher or the wave would distored. so I tried many other amplifier circuit I found by internet. here is the Version 2 which use the current of the OPA to control the constant current sources on the positive side and nagetive side, then a higher voltage amplifier could be controlled by the feedback resistor." alt="" class="bbc_img" />

author: PartialDischarge
author_rank: Super Contributor
timestamp: August 09, 2023, 08:10:30 am
content: Have you tested it? Do you have any measurements?

author: moffy
author_rank: Super Contributor
timestamp: August 09, 2023, 08:11:55 am
content: You should post a photo of the amplifier, I would love to see the size of the heatsink and the power supply.

author: ingenuwork
author_rank: Newbie
timestamp: August 09, 2023, 03:03:17 pm
content: The Version 1 Amplifier was tested and works well at DC to 500kHz and output 100Vp-p with power supply is ±67V, static current have to be 0.5A（for all 8 pair of N,P-MOSFET Power stage ）. if less static current or higher frequency, the sine wave become distorted. I used a 7038 violent Fan and a 240mm length wind tunnel heat sinks to cool it.The Version 1 Amplifier was made only one and used in my first core power-loss measurement so I have post it's picture later. I will show some related picture of the version 1. I do not know how to insert the picture between the text so I can only attach them.
A problem about check if my PSU work?(Use PC817) - Page 1
Forum section: electronics / projects

author: China NewBoy
author_rank: Regular Contributor
timestamp: November 08, 2019, 02:03:54 am
content: i have made a switching-mode power and i want my Atmega16 read if my power work,in the current scheme,i use the optocoupler pc817 which is connect to the PWM chip(ob2269)’s Vdd.but, i meet some problems , when the PC817 is connected to the VCC,the PWM chip dont work at all,because its Vin stay at 4.7V (the typical work volt is 19V).if the PC817 is NOT connected, i found the PSU work.i wonder what caused this problem.Here ↓ is my scheme pdf and some printscreen pics

author: xavier60
author_rank: Super Contributor
timestamp: November 08, 2019, 02:35:08 am
content: The startup current is very low. Vdd must have no load on it to start.Does the opto need to be driven from the primary side?

author: China NewBoy
author_rank: Regular Contributor
timestamp: November 08, 2019, 02:45:45 am
content: Quote from: xavier60 on November 08, 2019, 02:35:08 amim considering put my opto on the secondary side ,i will do some experiments on the breadboard to figure out if it can work on secondary sidehere ↓ is my new plan

author: China NewBoy
author_rank: Regular Contributor
timestamp: November 08, 2019, 02:55:50 am
content: Quote from: China NewBoy on November 08, 2019, 02:45:45 amit can work on the secondary side now!but im still wondering ,why adding load to VDD could impact the volt of Vin?

author: xavier60
author_rank: Super Contributor
timestamp: November 08, 2019, 03:02:05 am
content: Before the power supply starts, the only available current is via the VIN pin.

author: China NewBoy
author_rank: Regular Contributor
timestamp: November 08, 2019, 03:19:27 am
content: Quote from: xavier60 on November 08, 2019, 03:02:05 amim still wondering about why the VDD's LOAD can lead to the Vin's volt drop...maybe just becasue im still a newbie and i know nothing about the chip...but thank you really.the problem is solved now.
A problem about my switch mode Power supply - Page 1
Forum section: electronics / projects

author: China NewBoy
author_rank: Regular Contributor
timestamp: November 03, 2019, 06:57:26 am
content: i posted the topic on the power subject ,here is the linkhttps://www.eevblog.com/forum/renewable-energy/a-problem-about-my-switch-mode-power-supply/

author: Simon
author_rank: Unknown
timestamp: November 03, 2019, 09:21:55 am
content: Congratulations, and why did you feel the need to "announce" it elsewhere on the forum?
A problem about my switch mode Power supply - Page 1
Forum section: electronics / projects

author: China NewBoy
author_rank: Regular Contributor
timestamp: November 03, 2019, 11:56:06 am
content: i made a 24V switch mode power and it is suppoed to output the current of 2A ,but ,after i did some experiments,i found the Volt drop down to 22V when the LOAD is 12ohm. (there is weird sound -ZiZi) (pdf 's left upon part is the power supply unit) ,i think the circuit around OPA or tl431 is the key ,however, i just cant adjust it properly.my SchDoc Pdfmy PCB Dochope the problem solved

author: Simon
author_rank: Unknown
timestamp: November 03, 2019, 01:49:44 pm
content: If you start another topic twice you will be banned! i hope that is clear enough for you.
A problem about OPAmp and TL431 - Page 1
Forum section: electronics / projects

author: China NewBoy
author_rank: Regular Contributor
timestamp: November 06, 2019, 11:06:58 am
content: How the voltage between the 2.3 pin of TL431 will change(increase or drop？) after the input of op amp A and op amp B increases？the opa A and opa B are on the same chip

author: iMo
author_rank: Super Contributor
timestamp: November 06, 2019, 11:47:25 am
content: If the voltage at the pin1 against pin2 (gnd) of the TL431 goes above 2.5V the voltage between its pins 3 and 2 drops from Vxyz to 2.5V.In the schematics above there is a divider 147k/3k thus the voltage at pin 1 most probably never goes above 2.5V.

author: China NewBoy
author_rank: Regular Contributor
timestamp: November 06, 2019, 01:49:50 pm
content: thanks,the problem is solved now..casued by my stupid mistake
A professional looking of front panel design - Page 1
Forum section: electronics / projects

author: seksatta
author_rank: Newbie
timestamp: October 22, 2023, 06:07:36 am
content: Several project that I made end up with an 7 segment and tactile switch. Which is not perfered by user.So, I would like to ask the way of making a n professionl looking front panel control.Button , instead of tactile button what elese button v by the way I saw some project using a tactile switch pressed with some flex rubber or plastic button , I don't what it's calledDisplay 7 segment is it installed on flex PCB, or having a gap of frame to illuminate through.By the way I always love the panel of oscilloscope with somekind of rubber button with LED illuminating underneath. After I saw a rigol ocsilloscope tear down it has a switch on front PCB as in attached fileWhat it is called?Could you please share the knowledge or project that had been done?Thank you

author: Terry Bites
author_rank: Super Contributor
timestamp: October 22, 2023, 09:06:50 am
content: Search for "Membrane Switches" and "Low cost custom Membrane Switches" Capacitive switches seem to have taken over these days.Its all custom but it might make sense if you have large prodcution runs in mind. Get a chasample.eghttps://www.niceone-keypad.com/orhttps://www.jrpanel.com/about/jrpanel/You can make your own capacitive touch switches. eghttps://www.instructables.com/Capacitive-Switch-for-Arduino/Replace 7seg with Oled or LCDLook on Aliexpress for Oled touch or LCD touch, capacitive touch switch and Membrane Switches.
A project for creating projects - Page 1
Forum section: electronics / projects

author: Ivan Donev
author_rank: Newbie
timestamp: October 13, 2023, 11:16:58 am
content: Alright, last time I posted a good old we've-seen-it-all meteo station project, but here's something more substantial.It's a project for creating other projects quickly and intuitively. Sure it's got limitations, but hey - no programming and technicalities as well.The project is called Iot Cafe, it's open source, and although not well polished, I've released it in an "experimental" state, since there's an elephant cr#p load of work, most not even related with hardware, and there's only me to work it all out, so it takes more time than ideal.So yeah, here it is:https://iot.cafeI hope someone likes it despite still being quite rough around the edges.What do you guys think?

author: mikerj
author_rank: Super Contributor
timestamp: October 13, 2023, 11:32:25 am
content: I suspect you have forgotten add a link?

author: Terry Bites
author_rank: Super Contributor
timestamp: October 14, 2023, 07:03:28 am
content: IoUT/teashop works for me
A Quadrocopter Design Project - Page 1
Forum section: electronics / projects

author: SatoruSatake
author_rank: Newbie
timestamp: March 07, 2015, 12:15:11 pm
content: Hello everyone, I was given a project about using Arduino and Radar to design a Quadrocopter which can control its movement by mesuring the distance of the space nearby to decide move or not. How to do that?

author: Marco
author_rank: Super Contributor
timestamp: March 07, 2015, 01:01:57 pm
content: Modules for radar distance measurement are rather expensive ... are you sure your professor didn't mean sonar? (In which case I'd recommend googling for "quadcopter arduino sonar" without the quotes.)

author: dannyf
author_rank: Super Contributor
timestamp: March 07, 2015, 02:04:08 pm
content: Think about it in steps:1) can you measure the copter's spacial positions?2) can you control individual motor's lift?3) can you stablize the copter based on 1) and 2)?4) can you move the copter based on 1), 2) and 3)?5) can you measure the distance using the sonar?6) can you work the measurements into the decision to move the copter?Once you have those individual steps done, you are literally done with the project.

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: March 07, 2015, 04:23:37 pm
content: Do you have to design the quadcopter too, or are you given one?