hybridfree/eevblog-posts huggingface dataset:
Mains-powered project safety - Page 1
Forum section: electronics / projects

author: top955
author_rank: Newbie
timestamp: June 15, 2014, 03:35:59 pm
content: I am building a general-purpose inverter (60Hz AC --> 40-140 kHz AC) for powering flyback transformers, induction heaters, etc. The project link I'm referencing can be found here:http://uzzors2k.4hv.org/index.php?page=multiinverterI am aware of the hazards present from the mains-level voltage; however, what I am more concerned about is the fact thatschematicshows the a direct connection to unisolated mains.If it is possible to do so safely, I would like to use this circuit without an isolation transformer. However, that brings up several question:1. The author built his inverter within a salvaged ATX power supply metal enclosure. Can I ground the metal case, or would this cause problems due to the fact that the circuitry runs unisolated?2. If I did ground the metal case, I would certainly need to ensure that the MOSFET heatsinks did not make contact with the case---correct? Is there a practical way to isolate the heatsinks from the case?3. I realize it would be exceedingly dangerous to leave the case ungrounded, with the unioslated circuit. If this were necessary (due to 1 and 2), I suppose enclosing the ATX case with plastic would provide enough safety?Also keep in mind that I would be the only person using this inverter--it will not be sold/installed/used in an environment with anyone else, just to clear up potential liability concerns.Thanks!
Mains powered unit - considerations - Page 1
Forum section: electronics / projects

author: pat.stave
author_rank: Newbie
timestamp: January 25, 2024, 06:50:18 pm
content: I am currently working on the design of a ceiling mounted sensor unit. Currently early prototyping phase, thats the reason for the currently large an bulky design. Expeced volume about 3000 units/year.The unit will be mains powered (1x 230V AC).Currently the unit is powered by a HLK power supply, but i will swap this to aMeanWell IRM-03-5because the HLK unit does not contain have neccessary EMC filtering built-inThe unit will need to be CE declared and meet all european specifications.Please see the product animation here to get a feel for the product design and breakdown:https://youtu.be/ANU3neIkSnQI have some questions:Will the PCB mounted power suppy unit require a input side fuse on the PCB?What design changes needs to be done to meet double insulated / class 2 appliance class? Will conformal coating of the PCB have any effect on this, or would i need to add an additional layer around the entire power supply PCB? /

author: Randy222
author_rank: Frequent Contributor
timestamp: January 25, 2024, 09:41:53 pm
content: I take a guess.1) if it's a "fixture", then assumed to be on a panel breaker, aka OCPD, so no fuse needed, but, not a bad idea to perhaps include a fuse.2) as for certification, the CE code should list out the requirements for the fixture.

author: jonpaul
author_rank: Super Contributor
timestamp: January 26, 2024, 10:31:10 am
content: Bonjour, market isEU? UK? USA? Worldwide?It would be wiser not to base design of a consumer device on 240V mains on responses of a a forum.In case a finished product causes a fire, shock, or injury you and your firm are liable.Suggest to research the appropriate IEC, CE and (for USA sales) UL requirements for the safety product class.Finally beware many Chinese power supplies claim CE certification but fail to have required fire/isolation, or EMI compliance.Suggest to get a safety and EMI compliance consultant to review the design.Bon ChanceJon

author: Randy222
author_rank: Frequent Contributor
timestamp: January 26, 2024, 04:33:43 pm
content: Quote from: jonpaul on January 26, 2024, 10:31:10 amOP mentions Euro and 1x230vMost likely Euro market 1ph 230v 50HzThe design appears to not include the PSU. The PSU here seems to be a off-the-shelf unit used in final product.

author: temperance
author_rank: Super Contributor
timestamp: January 26, 2024, 11:53:41 pm
content: Those IRM-... power supplies are double insulated and require no input fuse. IRM... is the medical low leakage version and the power supply contains all the protection you will need. A fuse, MOV,...A double insulation symbol is also printed into the enclosure. Certificates are all available from the manufacturer.
Mains Powermeter project - Page 1
Forum section: electronics / projects

author: nikifena
author_rank: Regular Contributor
timestamp: February 03, 2015, 10:37:02 pm
content: Hi everyone. Just want to share with you this project which I finished couple days ago.A little bit history: I need a variable transformer with voltage and current reading. In the past I used two multimeters and variac, but because this is mains HV it was not so good and clean and easy to setup each time the tested device. I spent time to make a good and safe wiring etc.So I through how to make all in one device. The easiest way and my first idea was with two independent analog indicators for the voltage and the current. Next idea was with some specific IC's and lcd: much smaller and "modern"I searched for similar project over the net but there was just a couple projects and some of them used an obsolete IC. I searched around aliexpress and alibaba and I found pretty nice well build panel meter. I paid about 35-40Euro for this panel and than I started with the entire project.I had several ideas for more flexible power meter but than I decrease them just to current limiter with a lamp and light indicator of the mains line terminal.The schematics is pretty simple: Mains - resettable fuse - mains switch - 150W lamp with a bypass button - variac - power meter panel - mains output.The only one think which I need to finish is to add two leds or small neon lamps to indicate where is the mains line terminal.My idea is to indicate the line terminal from pretty low voltage: 40-50V up to 260V and I need to think how to make this easy.Below are few pictures of the building process. The last picture is what's inside the power meter. In my opinion this is well build device!

author: Yansi
author_rank: Super Contributor
timestamp: February 03, 2015, 10:46:59 pm
content: Nice build, I like that.By the way, what's that ZR7677 chip on the PC board near the 6 meg crystal?

author: nikifena
author_rank: Regular Contributor
timestamp: February 03, 2015, 10:53:23 pm
content: ThanksThis is a custom (probably re-branded) chip from the company which makes these panel metersHere is a link with a picture with better resolution:

author: Yansi
author_rank: Super Contributor
timestamp: February 03, 2015, 11:03:26 pm
content: Heh, 68 pixels width bonus :-)That meter definitely got my interest, never seen any like this one.I tried to look for that chip (seems like ASIC directly for the power metering app), but couldn't find any documentation whatsoever. So who knows.. Maybe it's some kind of clone of Analog Devices stuff, they make ICs for power metering, exactly in these SOP packages. I have one on my desk at work, it's some ADExxxx something module.What power is the variac? Just guessing 300? Did you fuse the OUTPUT TAP of the variac? It seems you have put the resetable fuse in the mains input and left the variac's output without a protection and that's wrong...

author: moffy
author_rank: Super Contributor
timestamp: February 03, 2015, 11:15:23 pm
content: Really nice build, nice project.
Mains product design for the USA - Page 1
Forum section: electronics / projects

author: DenzilPenberthy
author_rank: Frequent Contributor
timestamp: June 11, 2015, 03:02:10 pm
content: Hi All,I'm building a piece of equipment which essentially consists of a 19" rack case with a 24v PSU in it and four amplifiers. When I make kit like this for use here in the UK I'd use an IEC inlet with a single pole switch and a fuse both in the live conductor. This piece of equipment is going to end up being sent out to some folks in the states at some point.When you design things like this in the states, is the polarity of your supply guaranteed like it is here or do I need a double pole switch and double pole fusing?Cheers.

author: ConKbot
author_rank: Super Contributor
timestamp: June 11, 2015, 03:30:05 pm
content: Is it going to be 120V only or 120/208/240? If the latter, you definitely need double pole switching/fusing as both connections will be line. The usual NEMA outlets are polarized, however they werent always, so there can be older outlets in older facilities that are reversed.

author: Richard Crowley
author_rank: Super Contributor
timestamp: June 11, 2015, 03:58:38 pm
content: A properly-wired, grounded NEMA mains outlet will have the neutral node nominally at ground potential for a common 120V circuit. However a 240V circuit is practically guaranteed to have both conductors 120V above ground.However we we under the impression that in the rest of Europe, the "polarity" is undefined so, BOTH nodes must be assumed to be "hot".

author: Len
author_rank: Frequent Contributor
timestamp: June 11, 2015, 04:11:36 pm
content: Quote from: DenzilPenberthy on June 11, 2015, 03:02:10 pmYes, the polarity is guaranteed whether you use a 3-prong plug or a polarized 2-prong plug. These plugs won't fit into ancient unpolarized outlets, but such outlets are hard to find nowadays.Of course, the guarantee is only as good as the person who wired the outlet, but that's true anywhere.

author: DenzilPenberthy
author_rank: Frequent Contributor
timestamp: June 11, 2015, 04:20:52 pm
content: Ace, so I'll stick with a single pole switch and fuse then with an IEC inlet. This will be single phase 120v.Re polarity in Europe: I believe you're correct in that polarity is not ensured in continental Europe but here in the UK our wiring regulations do ensure it and sockets have a (usually single pole) switch in the live conductor and the plug has a single pole fuse in the live conductor.

author: TimFox
author_rank: Super Contributor
timestamp: June 11, 2015, 07:16:43 pm
content: When fitting a normal "IEC" line filter on a rear panel, I was surprised that the label did not distinguish the "line" and "neutral" connections to the load side. To be safe, I connected the power cord to a good outlet and verified which pin was close to chassis ground and which was hot before continuing.
maintained software to generate Voronoi toolpaths for PCB mechanical etching. - Page 1
Forum section: electronics / projects

author: mongo
author_rank: Contributor
timestamp: March 02, 2016, 09:17:32 am
content: It has been a while sense I have had to make a PCB at home, and as I mechanical etch with a hand built CNC machine I tend to use Voronoi toolpaths to help reduce the time and to be kind to the tooling.If you are not familiar here is a link to a paper, I won't link to my own work as I have a low post count.https://groups.csail.mit.edu/drl/wiki/images/7/7d/Vona_Rus_2005_Voronoi_toolpaths_for_PCB_mechanical_etch_Simple_and_intuitive_algorithms_with_the_3D_GPU.pdfAnyway the application I used (Visolate) to produce the toolpaths seems to be stuck in Java 6 land and I was hoping that the functionality may be common now but under another name.Thanks in advance.

author: awallin
author_rank: Frequent Contributor
timestamp: March 03, 2016, 07:33:20 am
content: FWIW, for voronoi diagrams I wrote openvoronoi a few years ago:https://github.com/aewallin/openvoronoimore recently a Java port was made:https://github.com/Rogach/jopenvoronoithese are low-level geometry libraries and a complete vd-PCB solution would require a lot of work on top of this (reading pcb/footprint/netlist files, displaying them, input/output through the libraries, and output of gerber files)Anders

author: jeremy
author_rank: Super Contributor
timestamp: March 03, 2016, 07:37:31 am
content: I never thought of or heard of this. Thank you for sharing it!

author: mongo
author_rank: Contributor
timestamp: March 03, 2016, 07:02:46 pm
content: Thanks Anders, I'll add that to my admittedly too long to do list. I cannot promise time lines but if I can contribute back I'll send a pull request. Python is great because of the ability to use numpy and python-usbtmc give and I have some great ideas.Really if, when Intel opensources the quark RTOS (not sure if they stayed on ViperOS) this month the Edison it may be perfect for EMC2 to get away from parallel ports. This would be great for small scale CNC and I think that mechanical etching will take off as the market is flooded with inexpensive CNC routers.

author: jeremy
author_rank: Super Contributor
timestamp: March 05, 2016, 11:53:58 pm
content: Mongo, have you seen machinekit? It is almost exactly what you are describing.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: March 06, 2016, 12:38:16 am
content: Interesting, but I'd like to see it with a positive-shape optimization rather than an absolute (and abstract) method. That is, as shown, it flagrantly ignores the shape of the ground fill, which in my designs is as critical as the shape of the signal connections (which are also blown out by this method, but signal nodes are usually smaller so this need not be as big a deal).To include this, one would have to define a set of points that belong to the polygon, and should remain fixed... but not so dense that little or no optimization is possible. I expect it's not as easily defined as the original case, unfortunately...Tim
Make a BLE Accessories that is connected to iPhone - Page 1
Forum section: electronics / projects

author: dalida
author_rank: Newbie
timestamp: December 08, 2013, 10:06:41 pm
content: Hi everyone ,I'm an iOS developer and I want to create a product that can communicate with my iPhone via BlueTooth Low energy (Bluetooth 4.0)I know how to develop the iOS part using Core Bluetooth, but I have no idea how to begin.I have two questions (knowing that I leave in France) :1/Have you links to products (programmable Bluetooth Low Energy chip) that I can buy on the internet to begin with ,knowing thatin my project I need also a sensor of movement , when the sensor of movement detect a movement it notify the chip and the chip notify my iPhone ?2/ What is the best programmable Bluetooth Low Energy chip that can be coupled with a sensor of movement and have you link of sensor that can be coupled with my chip?

author: ddavidebor
author_rank: Super Contributor
timestamp: December 08, 2013, 11:08:15 pm
content: A: raise moneyB: pay an engineer

author: BBQ
author_rank: Regular Contributor
timestamp: December 08, 2013, 11:25:46 pm
content: I guess you are looking for an accelerometer, or perhaps an IMU.Here is a good place to start:http://www.sensorsmag.com/sensors/acceleration-vibration/the-five-motion-senses-mems-inertial-sensing-transform-appli-6533?print=1

author: lgbeno
author_rank: Frequent Contributor
timestamp: December 08, 2013, 11:29:27 pm
content: TI sensor tag is a good kit based on cc2540 it's pretty easy to customize too.nRF51822 is probably the best BLE doc but the resources a little more difficult to get ahold of.If I were you, I would start out with the sensor tag.

author: Dago
author_rank: Frequent Contributor
timestamp: December 09, 2013, 06:10:11 am
content: Check out bluegigas selection of BT 4.0 modules, they're pretty inexpensive, small and easy to use:http://www.bluegiga.com/en-US/products/bluetooth-4.0-modules/

author: dalida
author_rank: Newbie
timestamp: December 09, 2013, 09:29:02 am
content: Think for your replies it was very helpful,I haver one more question :1/For the sensor I want a censor that detect the movement of any object that fly above the bluetooth device (1m) not the device itself and it works with this chip :http://www.bluegiga.com/en-US/products/bluetooth-4.0-modules/ble113-bluetooth--smart-module/
Make a dupont /pin header connector very high - Page 1
Forum section: electronics / projects

author: Saimoun
author_rank: Frequent Contributor
timestamp: May 15, 2024, 07:27:19 am
content: HiI've got a main PCB with a pin header and I want to connect a second PCB to it, but because of the design, that PCB is quite "far away" (about 15 / 20 mm).Ideally I would like to avoid using a cable, but rather have a simple pin header on the daughter board which will connect with the pin head on the main board.Any ideas on how to raise or find a very high connector?Thank you!---EDIT: ok sorry I spoke too fast, after a quick search it seems that the way to go is a simple through-hole female header (the header on the main board is 1.27mm) with long pins like that.But then what about the assembly (for production), can the header be mounted at a specific height? It would probably need a custom plastic part underneath to mount it at the correct height, no?

author: xvr
author_rank: Frequent Contributor
timestamp: May 15, 2024, 10:57:49 am
content: Use something like this -https://suddendocs.samtec.com/catalog_english/esq_th.pdf

author: coromonadalix
author_rank: Super Contributor
timestamp: May 15, 2024, 01:39:01 pm
content: 2.54mm 0.1" pitchhttps://www.pololu.com/product/2748you can search there for other models / male etc ....when you say 1.27" is it the pitch or the physical size ?

author: Saimoun
author_rank: Frequent Contributor
timestamp: May 16, 2024, 07:44:54 am
content: Quote from: coromonadalix on May 15, 2024, 01:39:01 pmThank you bothAnd I meant 1.27mm ha ha not inch sorry - so 0.05'' pitch
Make-before-break dual mosfet controller logic IC? - Page 1
Forum section: electronics / projects

author: AloyseTech
author_rank: Regular Contributor
timestamp: October 01, 2019, 04:32:03 pm
content: Hi,I'm looking for a make-before-break (MBB) complementary output IC to drive 2 mosfets using one 3V GPIO. Do you guys know any reference?

author: T3sl4co1l
author_rank: Super Contributor
timestamp: October 01, 2019, 06:23:18 pm
content: And the MOSFETs are wired how, and to what voltages? Push-pull, common ground? Half bridge? Isolated?Any TTL-compatible, two-channel independent gate driver will do, if it's PP or HB.Tim

author: AloyseTech
author_rank: Regular Contributor
timestamp: October 05, 2019, 08:35:21 pm
content: I have 2 voltage regulators in parallel and I would like to switch between them given certain condition. I have only one GPIO available. I plan to control the enable line of both regulators and eventually isolate their input/output. The part of the circuit I'm still working on is the cheapest/most integrated make before break driver from one single GPIO. My GPIO is 0/3V, and the regulators input voltage is around 4V.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: October 05, 2019, 08:56:32 pm
content: Can the regulators not simply be wired in parallel? The best controller is none at all!Some types contain internal diodes that allow power to back-flow from the output to the input (for example, 78xx series, most CMOS LDOs, all(?) buck or boost switchers), but some provide full isolation (where the input can go to zero, or even be driven negative, without drawing current from anywhere, or causing damage). May want to shop around for one of those?Otherwise, there are 5V-compatible power switches (e.g. for USB, and for local power management like this), and hot-swap controllers and such, that would fit the bill; they usually have logic-level inputs.If you want to do it yourself, you need either a back-to-back pair of MOSFETs (a single transistor has a body diode that will allow reverse current flow), or a single MOSFET with substrate connection like this,https://www.digikey.com/product-detail/en/microchip-technology/LND01K1-G/LND01K1-GCT-ND/4918738and a level shifter to guarantee the gate voltage goes up high enough to turn it on/off. Which may entail a charge pump for gate drive supply, and a gate driver, level shifter (logic gate), or a few more transistors. Preferably, with some current sensing and control logic, to turn off the switches in case of fault current (whether through the load, or from one source into the other).At which point, the hot-swap controller starts looking really nice, despite the added cost...Tim

author: SiliconWizard
author_rank: Super Contributor
timestamp: October 05, 2019, 11:56:40 pm
content: Quote from: T3sl4co1l on October 05, 2019, 08:56:32 pmYeah. And also, many LDOs have enable input pins. So you don't need any external switch, if you want to switch them.
Make Bluetooth 4.0 Low Energy Smart Car of Your Own - Page 1
Forum section: electronics / projects

author: mikeeugine
author_rank: Newbie
timestamp: December 04, 2014, 10:09:08 am
content: This BLE smart car is completed based on our latest design bluetooth 4.0 chiped- BLEDuino, L298 Motor shield, smart car body. The smart car production is simple, as DIY enthusiasts can complete their own smart car only in the form of building blocks, and the operation is also very simple, just controlling it via bluetooth 4.0 remote control, or mobile phone APP. Here we mainly explain the operation of smart car. With the help of the simple communication protocol, the car can achieve human-computer interaction, so DIY enthusiasts can build smart cars of their own on the basis of adding various sensors, camera modules.Source reading:http://www.elecfreaks.com/7830.htmlPreparation1.BLEDuino2.Smart car3.L298 Motor Shield4. ELF Joystick5. 12V lithium batteryOperating process1. Plug the L298 Motor Shield into the BLEDuino2. Access the smart car motor into the L2983. Fix the 12V lithium battery onto the smart car body via the cable tie4. The assembled remote control and BLE smart car was shown5. Remote control operating instructionsWhen the small car and the remote control access to electricity, the remote control will automatically connect the car. Push the remote control throttle to a certain position, and then push to the direction you need, the smart car would be driven to the direction. If you want the car stop, just pull the throttle to the lowest location. The Demo only briefly illustrates controlling the car by remote control, if the users want to control the car through the APP, the using method is the same.
Make low noise power from USB to supply microphone amplifier. - Page 1
Forum section: electronics / projects

author: Miyuki
author_rank: Frequent Contributor
timestamp: March 15, 2021, 05:36:02 pm
content: Hi.I am looking forward to building a USB microphone amplifier with ADC.Input is a classic dynamic microphone. So very low signal near its own impedance thermal noise. 200-500 OhmFirst stage gain about 60+dB something as TI INA163My question is about the best way to make noiseless power rails for the amplifier and ADC stageI know USB power is far from stable and have plenty of crap from what is going in the computer while cannot have directly connected much capacitance

author: t1d
author_rank: Super Contributor
timestamp: March 15, 2021, 09:07:10 pm
content: A simple and quiet power supply is always a battery. Voltage regulators, like the LM7805, do a good job of quieting noise. Well placed and specified capacitors can be a big help (Bigger is not always better.) Give us the details of what your power supply requires and we can give you more detailed answers.

author: tszaboo
author_rank: Super Contributor
timestamp: March 15, 2021, 10:08:36 pm
content: TPS7A series from TI are very good at cleaning up noisy sources. LC filtering for the higher frequencies on the input. Maybe a ferrite bead as well.Funny enough, I am working on something similar. I had enough from the noise in my condenser microphone, so I want to replace the internals, and place some 20dB gain in it. I spent 2 hours this weekend lookiing at the old EEVBlog videos with Doug Ford. It's insane to see that those designs were born to save cents on the BOM cost. Then they copied it in CN and changed parts without understanding it, ending up with these.

author: NiHaoMike
author_rank: Super Contributor
timestamp: March 15, 2021, 11:34:21 pm
content: Some LDOs like the LT3045 are specifically designed to attenuate noise even at high frequencies. It has an adjustable current limiting feature so you can add a lot more capacitance than you normally would be able to, although for something as low powered as a microphone amplifier, a few ceramic capacitors should be all that's needed.

author: Miyuki
author_rank: Frequent Contributor
timestamp: March 16, 2021, 06:52:17 am
content: Quote from: NANDBlog on March 15, 2021, 10:08:36 pmNice, that should do the jobWith something like LM4510 boost as most of these amps need relative high voltage to work properly 10-20Vbtw why not boost it to line levels directly when is that possibility and make the signal more noise resistant

author: Messtechniker
author_rank: Frequent Contributor
timestamp: March 16, 2021, 07:03:49 am
content: Quote from: Miyuki on March 16, 2021, 06:52:17 amDon't forget:Putting a line level mic in front of something loud like trumpet, drums etc. will overload it.

author: tszaboo
author_rank: Super Contributor
timestamp: March 16, 2021, 07:46:02 am
content: Quote from: Miyuki on March 16, 2021, 06:52:17 amI'm running the microphone fro ma 48V phantom supply.And yes, that's the idea. Place 20dB gain into the microphone's output directly, so it picks up less noise on the cabling.
Make Night Vision Camera From Old Smartphone ! - Page 1
Forum section: electronics / projects

author: Kedar264
author_rank: Regular Contributor
timestamp: December 21, 2017, 02:04:48 pm
content: This is How To Convert Any old smartphone Camera Into night Vision Camera Very Cheap But Useful HackWhen you get your new phone you usally just keep your old phone non working ( in drawers) so this is great hack that will turn it into a useful night vision camera ,FOR FREEE!Every Camera Sensor Has Ability To See Infrared i.e. Thermal Part of The Light But The Infrared Blocking Filter Inside Digital Camera's Protects The CCD Sensor From Burning With High Energy Infrared Light Such as Sunlight .Now , If We Remove The Blocking Infrared Filter The Camera Can Also Able To See Infrared Part of The Spectrum of Light ! Now if we use ir illuminator ,all of the sudden you can see in the darkCheck Out The Video To See How it Looks Like !https://youtu.be/S_otDBRFmGI

author: Bud
author_rank: Super Contributor
timestamp: December 21, 2017, 02:24:21 pm
content: If you want more people to read your posts, do not capitalize each word. It is annoying.

author: Mr. Scram
author_rank: Super Contributor
timestamp: December 21, 2017, 02:26:48 pm
content: Quote from: Bud on December 21, 2017, 02:24:21 pmHe just copypasted the caption of the clip.

author: Kedar264
author_rank: Regular Contributor
timestamp: December 21, 2017, 05:52:03 pm
content: i am just wondering is there any way to possibality to use this cam as thermal camera ,since it can detect ~ 900nm ir wavelength . maybe if we do this mod on a dslr camera we can increase iso to get some better results?

author: Mechatrommer
author_rank: Super Contributor
timestamp: December 21, 2017, 08:36:46 pm
content: Quote from: Kedar264 on December 21, 2017, 05:52:03 pmneed i copy paste the link?https://www.hackster.io/kedarnimbalkar/make-see-through-infrared-camera-for-cheap-802987Quotethis is a classical mod for night vision or infrared photography, other than seeing hot object (which i'm not sure how successfull it will be) you can go further mod for seeing "hot object" by adding ir filter to it, google it you'll know what i mean...
Make your own battery pack - 50W output  - Page 1
Forum section: electronics / projects

author: axolotyl
author_rank: Contributor
timestamp: June 21, 2018, 06:52:58 pm
content: We made caddies to hold LiPo batteries for your own battery pack, and are sharing the STL files.The charger output is USB-A, 2.7A per port, 50W total.Parts- Charger:www.pirlcharger.com- STL files:https://www.youmagine.com/designs/battery-caddy-for-the-pirl-charger- LiPo in red caddy: ZIPPY Compact 1000mAh 3S 25C Lipo Pack- LiPo in gray caddy: Turnigy 800mAh 3S 20C Lipo Pack (E-flight Compatible EFLB0995)- Build details:https://www.kickstarter.com/projects/pirl/the-ultimate-charger-for-power-users/posts/2215614We'll be adding more larger battery case designs on Youmagine.
MakePCB panelization - Page 1
Forum section: electronics / projects

author: drwho9437
author_rank: Regular Contributor
timestamp: November 26, 2010, 07:29:14 pm
content: I was wondering if anyone has gone with MakePCB for panelized designs. They offer panelization of your design but I need fiducials, etc.Basically I have never panelized a design before, and don't really know how I should indicate where to put the vscoring. Perhaps it is universally the same even if you don't use makePCB. PCBcart seems more expensive for my volume.I wrote them about this but I didn't hear anything back, so I'd also be interested in any experiences with them.PS: As some who is colorblind I found the registration for this forum needlessly hard.

author: baljemmett
author_rank: Unknown
timestamp: November 26, 2010, 09:29:02 pm
content: [Can't help with the question, but your postscript caught my eye:]Quote from: drwho9437 on November 26, 2010, 07:29:14 pmHmm, is there a new one? I don't remember colour featuring when I registered -- although the other day I saw an anti-bot scheme on some blog or other that was "read this resistor colour code", which I find impossible without resorting to using an image editor to sample and match the bands. So I feel your painNow, where's my meter? I have several decades of E12 resistors to sort into bins this evening!

author: Zero999
author_rank: Super Contributor
timestamp: November 26, 2010, 09:55:19 pm
content: If there's a resistor colour code test, it should have text as well as colour.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: November 26, 2010, 11:28:59 pm
content: [quoteI was wondering if anyone has gone with MakePCB for panelized designs. They offer panelization of your design but I need fiducials, etc.You could put per-board fids and only use teh outermost ones, as long as you know what their panelisation pitch will be . Tooling holes may be more of a problem though unless your PCB has large unpopulated borders.

author: Zad
author_rank: Super Contributor
timestamp: November 26, 2010, 11:50:30 pm
content: It is the Adafruit site that uses the resistor colour codes.
Makerbot Thing-O-Matic assembly instructions - Page 1
Forum section: electronics / projects

author: SenSeS
author_rank: Contributor
timestamp: February 24, 2016, 10:04:41 pm
content: I can't find the assembly instructions for the makerbot Thing-O-Matic. Makerbot removed them from their website. I found this:http://makerbot.wikidot.com/thingomatic-doc:thingomatic-assembly-instructionsbut the pictures are gone. Does anyone still have the assembly instructions (complete with pictures) somewhere? It would help me out a great deal. Thanks!

author: NickAmes
author_rank: Contributor
timestamp: February 25, 2016, 03:27:54 am
content: Use the wayback machine:http://web.archive.org/web/20120307162208/http://www.makerbot.com/docs/thingomatic/instructions-for-educators/

author: SenSeS
author_rank: Contributor
timestamp: February 25, 2016, 09:06:25 am
content: Excellent, thank you!
Makerfaire project? - Page 1
Forum section: electronics / projects

author: EEVblog
author_rank: Unknown
timestamp: August 05, 2013, 02:25:59 pm
content: Now that (mini) Makerfaire is coming to Sydney, I kinda feel compelled to do a cool project to show off. i.e. as in something Joe Average would find cool.Ideas?

author: AlfBaz
author_rank: Super Contributor
timestamp: August 05, 2013, 03:00:56 pm
content: You may still have one you got in one of your mail bags, the plasma speaker. I found that super cool

author: AlfBaz
author_rank: Super Contributor
timestamp: August 05, 2013, 03:03:00 pm
content: ... playing music being played on an oscilloscope in the oscillofun vein

author: EEVblog
author_rank: Unknown
timestamp: August 05, 2013, 10:36:14 pm
content: Quote from: AlfBaz on August 05, 2013, 03:00:56 pmThat one popped into my mind as well.

author: nctnico
author_rank: Super Contributor
timestamp: August 06, 2013, 12:55:45 am
content: A live teardown?

author: AlfBaz
author_rank: Super Contributor
timestamp: August 06, 2013, 01:18:09 am
content: Quote from: nctnico on August 06, 2013, 12:55:45 amI'd go just to decipher that tune he whistles in fast forward

author: Halfdead
author_rank: Contributor
timestamp: August 06, 2013, 01:48:50 am
content: Everybody loves a good Tesla coil.
Makeshift DAQ system - Page 1
Forum section: electronics / projects

author: reagle
author_rank: Unknown
timestamp: February 24, 2013, 07:30:27 pm
content: Just posted a writeup on my blog of one of those "Oh crap, it's Friday and we need it today" solution to needing a fast data-logger.http://kuzyatech.com/a-make-shift-data-acquisition-systemIt's a bit crude but did the job:)
Making a -0.25V ref - Page 1
Forum section: electronics / projects

author: richcj10
author_rank: Unknown
timestamp: July 17, 2013, 02:15:14 am
content: I am using a LMP7721 op-amp in a design. I want to give V- -0.25v to allow a true 0-5v output.I have a design for a LM2787 to output that kind of voltage. But, they are out of stock and in the wrong package for me to use.Any other suggestions?Thanks as always,Rick

author: codeboy2k
author_rank: Super Contributor
timestamp: July 17, 2013, 04:24:52 am
content: You don't need anything fancy... That opamp has a 6V supply range. You can simply use a diode drop... use a 5V voltage regulator with it's ground node raised above the (now -650mV rail) by a diode drop.The point where your diode meets the ground pin of the regulator is the "system ground reference", or "0" volts so the speak, or the point of the GND symbol. The other rail is now -650mv below ground.see attached spice.

author: Andreas
author_rank: Super Contributor
timestamp: July 17, 2013, 07:45:08 pm
content: A Schottky diode (BAT48 or LL103) will give around 0.25-0.35V at 1-10mA.with best regardsAndreas

author: richcj10
author_rank: Unknown
timestamp: July 20, 2013, 03:07:16 am
content: What about the noise created from the diode?

author: SeanB
author_rank: Super Contributor
timestamp: July 20, 2013, 05:14:12 am
content: 100n across the diode reduces it a lot.
Making a "mirror switch" - Page 1
Forum section: electronics / projects

author: new299
author_rank: Regular Contributor
timestamp: September 09, 2016, 05:16:27 pm
content: Hi guys,Recently I've been hacking around with cheap Chinese dumb switches. I picked up a bunch of eBay which were based on the IP178G. This is a cheap Chinese switch on a chip which as a (for Shenzhen) pretty good datasheet. I figured some people here might also be interested in the project.Turns out there's a bunch of stuff you can configure on them using either a proprietary serial protocol, or from EEPROM on boot.The whole EEPROM thing was a massive rabbit hole. The datasheet lists a AT24C01 to C16 EEPROM. That's a deprecated part. I figured the AT24C01A would be compatible. Turns out that's very much not the case:http://41j.com/blog/2016/09/the-at24c01-and-the-at24c01a/The AT24C01A added device addressing. The device address is set by 3 pins on the chip, and is also sent in every read/write op. The AT24C01 seems to be totally unavailable outside China. On taobao there appear to be a bunch of clones, and I guess it's alive and well in the Shenzhen supply chain.So this meant I had to fallback to a microcontroller. I needed up using an ATTINY85 and document my initial experiments with an Arduino here:http://41j.com/blog/2016/08/fiddling-with-a-cheap-5-port-dumb-switch-to-add-vlansport-mirroring/and final version using an ATTINY85 here:http://41j.com/blog/2016/09/mirrorswitch/I've always wanted a switch with a static port mirroring configuration. This allows you to monitor traffic on a port, much like you used to be able to using hubs many years ago. I'm now selling them on my shop (basically a hobby, I've only sold one):http://www.whitefordresearch.com/products/mirror-switch
making a fixed bias amp sound more like a cathode biased one - Page 1
Forum section: electronics / projects

author: Deactivated-1
author_rank: Frequent Contributor
timestamp: June 05, 2020, 10:51:51 pm
content: i really want fixed bias because it can usually output more power and is easier to bias, but i like the more commpressed and smoother tone of a cathode biased output. can i make a fixed biased amp sound more like a cathode biased one?

author: ch_scr
author_rank: Frequent Contributor
timestamp: June 06, 2020, 08:57:08 pm
content: Maybe have a Cathode biased preamplifier stage generate you harmonics for you so it sounds "right" and have the efficient power stage after that?
Making a MOSFET/IGBT gate drive test load? - Page 1
Forum section: electronics / projects

author: Artlav
author_rank: Frequent Contributor
timestamp: May 18, 2014, 07:42:03 pm
content: How can one make a realistic test load for developing and/or debugging a gate driver for a large IGBT or MOSFET brick?Specifically, how to reproduce Miller effect without testing the thing on live 100A switching transistor?I was thinking along the lines of using some common MOSFET with added capacitors and resistors to match the input, output and reverse capacitances of the big brick.Since Miller effect is related to reverse transfer capacitance, making that one larger should amplify it, right?Would that work?How is it done properly?I looked in various driver IC datasheets, but they only describe current tests or timing tests with capacitative load.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: May 18, 2014, 09:43:40 pm
content: Use an R+C with C = (Qgs(tot) max) / (delta Vgs). R can be either internal RG (if specified), or a guess (an ohm or a few?), plus whatever external resistance your drive circuit will use, or you can add them together in a single resistor.Note that, if you're intending on driving large IGBTs with negative turnoff, Qg is fairly substantial at Vge < 0. It's not always specified, and every manufacturer has their own test conditions. You may want to measure or overestimate the requirements.If you require the Miller step for best representation (like, say you're building and testing a driver with a design like a Fairchild MillerDrive), you might be better off using the real thing...or, a suitable simulation of it, as you note.For that, I would suggest a somewhat smaller power transistor (say, 60V 40A -- IRFZ46N or the like?), with added Cgs and Cgd, and a fairly substantial supply and load resistor. Say, 20V and 20A, 1 ohm load. (The load needs to be pretty stiff, so it doesn't get pushed around by the peak gate current. That's 400W when on, or 200W average at 50% duty. It'll get hot, but won't consume nearly as much power as the end use, presumably.) Take suitable precautions, like an antiparallel diode, or snubber, on the resistor, to account for inevitable inductance (wiring plus resistor winding inductance -- even if noninductive).Tim
Making a new galaxy buds case , need help with polarity and charging current. - Page 1
Forum section: electronics / projects

author: lgbattery
author_rank: Newbie
timestamp: September 14, 2021, 07:59:38 pm
content: Bought these off a friend yesterday and immediately lost the case while using them on the train yesterday. Now I have a great excuse to make a better one, My plan is to make a simple case that is based off a replaceable 18650 cell with a USB-c charge controller, but before I begin I have a few basic questions about polarity, charging voltage, etc... that Im hoping some of you guys could help me with. Sadly it seems most of the search results for "How to charge galaxy buds without case" turn out to be "How to buy our new product".anyway, three questions i have.1. In the current very badly drawn schematic I have 3.7v going into the earbud, but I have a feeling that that will need to be stepped up to 5v before entering the earbud otherwise it wouldn't make sense how for example: the original case is sitting at 50% battery (3.4v ~) but it can charge the buds to 100% (4.2v).2. Anybody who has the galaxy buds case can you confirm that my polarity in the image below is correct (not the drawing)? this would also answer my first question because it should read 5v on a multi meter if my assumption is correct.3. Will i need to limit the current going from the battery into the buds? having a 5A 18650 drain all of its power into a tiny 150~ mah LiPo cell doesnt seem like a very good idea to me but im wondering if this issue gets ironed out in the charge controller that the earbud itself has inside of it.Thanks to any one who can help me out with this

author: thm_w
author_rank: Super Contributor
timestamp: September 14, 2021, 09:38:40 pm
content: This will not be such an easy task. I would suggest simply buying a case:https://www.ebay.com/sch/i.html?_from=R40&_nkw=buds+case+chargingYes there will be some sort of boost converter in the base to allow it to charge the earbud battery to a higher voltage than its own.They may have the charge management on the main board, or on the earbuds themselves. They'd save a bit of space by putting it in the base, but, would still want a battery protection IC for over/undervoltage. I can check the voltage later.edit: looks like I don't have the same model as you, but my charging case was outputting 1.35V with the negative in the center and positives on the outer side. Maybe some kind of sense voltage until the battery is connected.
making a positive solder mask layer/section? (bounded by PCB edge) - Page 1
Forum section: electronics / projects

author: incf
author_rank: Frequent Contributor
timestamp: April 08, 2025, 04:42:59 pm
content: Is there some way (in a tool like altium) to create or export a layer with solder mask information that is positive and bounded by the PCB outline? "It's vaguely like a copper pour, but different."I've tried a few different things. I think it's more complicated (ie. involves geometric operations between multiple layers) than one might think.-> using the existing solder mask layers involves doing geometric operations on exported layers?-> using copper pours and copper pour cutouts possibly might work?-> other ways?I have a feeling this is a problem that "I don't need to solve" since manufacturers routinely deal with inverted layers.Nevertheless, we do some nonstandard manufacturing processes and I would like to figure out how to convince something like a PCB layout tool like Altium to do it automatically (if possible).

author: xvr
author_rank: Frequent Contributor
timestamp: April 08, 2025, 08:54:35 pm
content: QuoteYes, they do.But they don't use CAD tools (like Altium) for this process, they use CAM tools (like CAM350https://www.downstreamtech.com/products/cam350/)CAD - Computer-aided DesignCAM - Computer-aided Manufacturing

author: ajb
author_rank: Super Contributor
timestamp: April 08, 2025, 10:07:44 pm
content: Is it actually for soldermask, or something else? What sorts of shapes are you trying to end up with?In Altium you can use mechanical layers for whatever, but it might take a lot of faffing around with rules to get normal soldermask layer behavior to work as well, if you need it. You can do all sorts wacky things if you can find the right(wrong?) way to (mis?)use the standard tools, eg:https://www.eevblog.com/forum/altium/custom-soldermask/msg5389328/Alternatively, might be easier to draw what you need in positive shapes on a mech layer and then post process the gerbers?

author: incf
author_rank: Frequent Contributor
timestamp: April 08, 2025, 10:16:07 pm
content: Quote from: ajb on April 08, 2025, 10:07:44 pmIt's an insulating layer that goes between overlapping metal layers in certain sections. Rectangular cutouts from rectangular sections (although arcs and polygons would be nice, they are not required).In Altium, I'm currently using footprints with the type set to "jumper" along with copper pours and copper pour cutouts (using inner copper layers as insulator layer). A bit clunky to set up. Had to make custom footprints with cutouts. Having to assign a net to an insulating layer's pour feels a bit silly. But, it seems to work adequately.But, I'll leave the thread open just in case.

author: thm_w
author_rank: Super Contributor
timestamp: April 09, 2025, 01:26:19 am
content: You can move the thread here:https://www.eevblog.com/forum/altium/
Making a robust Y-Joint in a cable - Page 1
Forum section: electronics / projects

author: ezalys
author_rank: Frequent Contributor
timestamp: August 08, 2020, 03:12:11 pm
content: I'm finding myself in a situation where I have one 8 conductor cable (+ shield) that needs to branch into two four-conductor (+ shield) cables. What's the most mechanically and electrically sound way to do this? My first impulse is a project box with a couple of cable glands... but this seems like overkill. I also am thinking of using a bunch of self-adhesive heat shrink, but I'm not sure if this is mechanically sound or conducive to good shielding. I'm also thinking of just soldering everything together and then potting the junction... what would you do?

author: NiHaoMike
author_rank: Super Contributor
timestamp: August 08, 2020, 03:27:36 pm
content: Solder the wires together, each individually heat shrinked (except the shield), shielding done with copper foil wrapped around the pairs and soldered to the shield ground. Then add a layer of hot glue over it and finish off with heat shrink, using enough length to allow it to grab onto the outer insulation on the cables. It would be better to have a little too much hot glue than not enough, since it's very easy to clean up the excess after letting it cool.If moisture resistance is important, use electronics safe silicone adhesive instead of hot glue. (The curing time will be much longer than usual due to it being sealed in heat shrink.)