hybridfree/eevblog-posts huggingface dataset:
Best adhesive for flex PCB (Kapton/polyimide) - Page 1
Forum section: electronics / projects

author: AMS
author_rank: Contributor
timestamp: February 09, 2017, 11:32:11 pm
content: Hi all,Once again I need the advice of you guys. I am working on a project that I need to fix a small piece of flex PCB on a curved surface (wrap half way around a cylinder of approx 20mm Diameter) I can used any double sided tape which is thicker than 0.1mm as the diameter of the cylinder and the flex PCB should not exceed 20mm+Flex+0.1 I was thinking of using a form of adhesive (i.e. spray adhesive) to permanently glue it to the surface but I am not sure which type of adhesive will work best on flex PCBs. Does anyone here have an experience with a glue that they used for a similar application?

author: flolic
author_rank: Frequent Contributor
timestamp: February 10, 2017, 12:12:59 am
content: Look for 3M 467MP 200MP, or 3M 300LSE double side tapes. I prefer the first one for flex cables (or PCB-s).

author: coppice
author_rank: Super Contributor
timestamp: February 10, 2017, 02:06:12 am
content: If you are really talking about Kapton, its a polyimide, not a polyamide.

author: RobK_NL
author_rank: Frequent Contributor
timestamp: February 10, 2017, 08:40:03 am
content: I've had very good results with SBR-based spray adhesive. Something like this:http://nl.farnell.com/pro-power/ppc105/adhesive-spray-500ml-aerosol/dp/1206537will probably do the trick (not the stuff I use, but that's from a Dutch manufacturer; not sure if that's available in the UK).

author: AMS
author_rank: Contributor
timestamp: February 11, 2017, 01:18:50 am
content: Quote from: RobK_NL on February 10, 2017, 08:40:03 amThanks a lot guys I will try the PPC105 for now but is there any UV curable option available? I might want to clean the PCB with alcohol and it would help if the glue can withstand the alcohol.
best battery for low noise preamplifier? - Page 1
Forum section: electronics / projects

author: SArepairman
author_rank: Frequent Contributor
timestamp: April 18, 2014, 06:28:14 pm
content: So I need a power source for my pre amplifier.I need ~4-5 volts per rail.. (bipolar)two options come to mind:4x lithium battery for +-6v. I like this solution because I could seal the whole thing up well and just leave a external jack and switch to plug it into a lab power supply for charging (I don't expect this thing to be used much).rechargable c/d cells - I don't know how many I need, 6 I assume (1.5x6 for 4.5--4.5v).The problem is that I don't have a charger for these cells, so I would need to buy one, since you can't recharge certain battery types with a lab power supply (I would need to keep track of temperature and its kind of a pain).I have eneloop AA rechargeable batteries. They are nice but they are only 1.3V, so I would probably need four of them per rail, and that is not much current (I expect this to take ~50-100mA).Eneloops would cost 20$ and require dis assembly for recharging.I am not sure what type of lithium battery I would use, I 3000+mAh would be nice.I wanted to run the op-amp just from the batteries without a regulator to keep the circuit simple.

author: Andreas
author_rank: Super Contributor
timestamp: April 18, 2014, 06:35:25 pm
content: Quote from: SArepairman on April 18, 2014, 06:28:14 pmI have tried to test eneloop AA batteries (packs of 8 AA cells) for noise.Noise is lower than my noise amplifier (around 0.12 uVpp at Input)so I could not measure the noise of the AA cells.With best regardsAndreas

author: Richard Crowley
author_rank: Super Contributor
timestamp: April 18, 2014, 06:38:06 pm
content: Quote from: SArepairman on April 18, 2014, 06:28:14 pmWhy not use ordinary primary cells? Why even fool around with rechargable for something "not used much"?

author: SArepairman
author_rank: Frequent Contributor
timestamp: April 18, 2014, 06:51:26 pm
content: Quote from: Richard Crowley on April 18, 2014, 06:38:06 pmcant help myself addiction

author: rdl
author_rank: Super Contributor
timestamp: April 18, 2014, 07:09:35 pm
content: QuoteQuoteSo how were you planning to charge the lithium batteries from your lab supply?

author: SArepairman
author_rank: Frequent Contributor
timestamp: April 18, 2014, 07:10:38 pm
content: Quote from: rdl on April 18, 2014, 07:09:35 pmconstant current then constant voltage based on batteries charge capacity.Its how I charge my flashlight batteries.i have a whole bunch of switches here on hand too.
Best BLE Module for Arduino? - Page 1
Forum section: electronics / projects

author: Thane of Cawdor
author_rank: Regular Contributor
timestamp: September 17, 2017, 07:51:47 am
content: Hi everyone,I just wanted to find out what your recommendations are for choosing one of the many Bluetooth Low Energy modules out there. I'm particularly interested in Arduino compatibility and good documentation.Thanks!

author: danadak
author_rank: Super Contributor
timestamp: September 17, 2017, 10:44:38 pm
content: Cypress PSOC -http://www.cypress.com/products/psoc-4-ble-bluetooth-smarthttp://www.cypress.com/documentation/development-kitsboards/cy8ckit-042-ble-bluetooth-low-energy-42-compliant-pioneer-kitRegards, Dana.

author: Thane of Cawdor
author_rank: Regular Contributor
timestamp: September 19, 2017, 10:38:31 am
content: Thanks for that! Is the PSoC compatible with the Arduino IDE or is it a standalone thing?

author: mauroh
author_rank: Frequent Contributor
timestamp: September 19, 2017, 10:46:03 am
content: I bought an ESP32 development board because I had the same need.It can be used also inside the Arduino IDE, whatch this:http://www.instructables.com/id/How-to-Use-BluetoothBLE-With-ESP32/Unfortunately the approch in the videois not the bestbut the BLE capability of the ESP32 looks promising.Mauro

author: zeqing
author_rank: Regular Contributor
timestamp: September 21, 2017, 03:30:00 am
content: the sparkfun ble breakout?https://www.sparkfun.com/products/13990with detailed guide on the usage with Arduino.

author: Wimberleytech
author_rank: Super Contributor
timestamp: September 22, 2017, 08:50:44 pm
content: I have used the Nordic NRF8001 on a project with a Silabs C8051F931. I started with the Nordic code written for the Arduino and ported it to the Silabs MCU. Later on, I used the 8001 with an Arduino Uno and also starting with the Nordic code. No edits were required!! Came right up with no issues.

author: ez24
author_rank: Super Contributor
timestamp: September 22, 2017, 09:06:48 pm
content: .

author: zeqing
author_rank: Regular Contributor
timestamp: October 28, 2017, 02:55:54 am
content: the CC2640https://www.makerfabs.com/index.php?route=product/product&product_id=512or nRF52832https://www.makerfabs.com/index.php?route=product/product&product_id=511
Best board color for hiding no-clean flux, finger prints, etc....? - Page 1
Forum section: electronics / projects

author: george graves
author_rank: Super Contributor
timestamp: December 13, 2015, 03:24:10 am
content: So you know how silver cars don't show dirt as much as a black car?What board colors look the best when using a no-clean solder paste - or a board that might not be washed perfectly clean?

author: amc184
author_rank: Regular Contributor
timestamp: December 13, 2015, 03:50:12 am
content: I'd say anything dark, but maybe not black, as that will show vapour marks badly (black also makes traces far harder to follow, another good reason to avoid it). I'd use blue, red or plain old green.You could also consider using a solder with Crystal flux or similar, where the flux residue is transparent.

author: Mechatrommer
author_rank: Super Contributor
timestamp: December 13, 2015, 04:35:29 am
content: Quote from: george graves on December 13, 2015, 03:24:10 amyou paint your car with dirt, and it will not show dirt ever... the fact it still show up is because there is a clear layer on top of most paint, so dirt will manifest itself as gloss differential...Quote from: george graves on December 13, 2015, 03:24:10 amso.... what color you want to hide? is that color you want to paint...

author: Ian.M
author_rank: Super Contributor
timestamp: December 13, 2015, 04:50:17 am
content: daggy brown SRBP

author: calexanian
author_rank: Super Contributor
timestamp: December 13, 2015, 05:57:36 am
content: I would say plain old green as well. An alternative for you may be using water clean flux. I use it from time to time when we have components that solvent based cleaners might effect. Distilled deionized water is cheap and easy and you can just air dry the boards. They come out so pretty.

author: george graves
author_rank: Super Contributor
timestamp: December 13, 2015, 09:06:41 am
content: Thanks - I'm kinda happy with my Kester 256EP at the moment. It's so forgiving for guys like me doing small runs.
Best cabling/connection configuration for addressable LED strips??..... - Page 1
Forum section: electronics / projects

author: Smokey
author_rank: Super Contributor
timestamp: December 18, 2023, 08:17:10 am
content: Scenario:Say I'm using something like a string of WS2813 addressable LEDs.https://www.normandled.com/upload/201605/WS2813%20LED%20Datasheet.pdfAlso say the string is about 100 LEDs long and draws about 5A at 5V. (yes I know about distributed power supplies for these strips).The connections into the string are:+5VDataGround... and the cable run between the controller/power supply and string is about 6 feet long. Both power and data come from the controller.The data rate for these is about 800kbps, which isn't crazy fast.Question:Would it make more sense to run everything in one three-conductor cable with +5V, Data, and Ground in one cable, or run a two-conductor higher awg cable for Power (+5V, Gnd) and another separate two-conductor signal cable for the data signal (Data, Gnd)? All cabling would have shielding.What is the longest runs you guys have gotten away with while having everything in one cable?Note: For long cable runs, I have a differential RS422 solution. But for "less long" cables it's still single ended like described above.
Best connector for testing TO-220, TO-247 etc packages (milliohm meter) - Page 1
Forum section: electronics / projects

author: Hiemal
author_rank: Regular Contributor
timestamp: July 23, 2019, 04:51:40 am
content: Hi guys.Designed a milliohm/MOSFET tester/meter and am currently stuck on figuring out a reliable connector methodology. In essence, a 250 mA constant current source to measure voltage drop across whatever you're testing. It works perfect, just need to solve the connector problem.Right now I've made sort of pseudo kelvin clips by soldering on magnet wire to the near end of grabber clips like these:Which works, but doesn't feel super "nice" to use and can give errant readings depending on how good the clip grabs onto the leads.Also gave a thought towards ZIF sockets, but can't get a good kelvin connection (does it matter that much in this case?)Also thought about terminal blocks, but unsure how reliable it would be and also unsure if I can get a size small enough for TO-220 spacing.Any other good suggestions?

author: tautech
author_rank: Super Contributor
timestamp: July 23, 2019, 05:03:39 am
content: Old floppy drive power connector. It's 4 pin but you can easily narrow it to 3.

author: exe
author_rank: Unknown
timestamp: July 23, 2019, 06:17:42 am
content: I used terminal blocks with 2.54mm spacing. Works fine, but not sure if it is suitable for kelvin connection and measurements down to milliohms.
Best DSP starter kit? - Page 1
Forum section: electronics / projects

author: gregariz
author_rank: Frequent Contributor
timestamp: July 12, 2011, 06:25:24 am
content: Hi Guys,I've been looking for a DSP starter kit, specifically for audio processing and was wondering if anyone has any experience with such a kit. I've looked at both the Freescale Symphony and the Microchip DSPic starter kits.Microchip DSPic $60http://www.microchip.com/stellent/idcplg?IdcService=SS_GET_PAGE&nodeId=1406&dDocName=en534506Freescale Symphony Soundbite $150http://www.freescale.com/webapp/sps/site/prod_summary.jsp?code=SYMP_SOUNDBITEI would jump on the DPic kit but for one reason, I am wondering if it has enough grunt to crunch an FIR filter in real time? They only talk about record and playback in the documents which has me thinking thats all it has the crunch power to do?Anybody with experience with these? or somthing better in this price bracket?tks.

author: johnmx
author_rank: Frequent Contributor
timestamp: July 12, 2011, 10:11:28 pm
content: I would consider the TMDX5502EZDSP or the TMDX5509EZDSP. They cost under $100.Don’t know what happened to TI’s website, I cannot open the webpage of those development tools.http://links.mkt2223.com/ctt?kn=11&ms=MzUwMDIyNgS2&r=MjEzOTYzNzEwNzIS1&b=0&j=MTEwMzU1MTc2S0&mt=1&rt=0

author: gregariz
author_rank: Frequent Contributor
timestamp: July 12, 2011, 10:31:16 pm
content: Thanks John,https://estore.ti.com/Search.aspx?detail=1&k=TMDX5505EZDSPThat looks like a nice board and the price is right..... I think its going to come down to which is easiest to program, who has the best demo code/docs and utilities. Sorting that might be a bit of a time suck...hmmm...
Best forums for physics, optics and mechanics? - Page 1
Forum section: electronics / projects

author: ricko_uk
author_rank: Super Contributor
timestamp: May 28, 2020, 12:47:58 pm
content: Hi,EEV blog is a great community and by far the best for electronics. Are there equally good and very active (!!) forums for each of the following?- optics- physics- mechanicsmany thanks
Best free tool to script rs232 communication - Page 1
Forum section: electronics / projects

author: MrMetthew
author_rank: Regular Contributor
timestamp: August 28, 2018, 12:03:11 pm
content: Hi guys,For some debugging I am searching a good tool to simulate serial port communication. I just want a tool where I can easilly program things like "send one message" - "wait x amount of ms" - "send other message" - and so on.I am trying to use script communicator but cant get it to work :/. I would prefer something easy like arduino language for example. If I had a level shifter laying around I would actually program an arduino to generate the bussload.Sincere,Mathijs

author: ebclr
author_rank: Super Contributor
timestamp: August 28, 2018, 12:07:29 pm
content: C#

author: rjp
author_rank: Regular Contributor
timestamp: August 28, 2018, 12:15:29 pm
content: you could use python or csharp if you have a pc with serial ports.or just spring for the max232 breakout and byo with an arduino... wack a couple of dials and buttons on it and you can automate all the usual variations.their is plenty of stuff that will do TTL level or USB serial options, actual serial line level gear with a D9 is getting quite rare.

author: sokoloff
author_rank: Super Contributor
timestamp: August 28, 2018, 12:51:52 pm
content: I've used expect for a lot of communication automation over the years.It's a tcl package.https://www.tcl.tk/man/expect5.31/expect.1.html

author: kirill_ka
author_rank: Frequent Contributor
timestamp: August 28, 2018, 01:16:16 pm
content: I find Tcl convenient to work with serial ports. It works well for both binary and text transfers.

author: TK
author_rank: Super Contributor
timestamp: August 28, 2018, 01:26:40 pm
content: +1 for expect

author: MarkL
author_rank: Unknown
timestamp: August 31, 2018, 02:59:13 pm
content: I would also highly recommend expect, but I'd also like to point out that there are a lot of other programming language bindings for it besides Tcl.Expect can be used with perl, C#, python, C/C++, and a bunch of others. I use it quite a bit with perl.Good place to start:https://en.wikipedia.org/wiki/Expect
Best guess of VA rating and intended purpose of transformer - Page 1
Forum section: electronics / projects

author: ledtester
author_rank: Super Contributor
timestamp: October 27, 2020, 04:01:15 am
content: I have this transformer and I'm curious as to what its intended use was and what the VA ratings of each of the secondaries would be.Also, about the thermal cutoff fuse -- is that likely to be one that resets or a one-time use fuse?Edit: It weighs about 3 pounds.Thanks!

author: Kleinstein
author_rank: Super Contributor
timestamp: October 27, 2020, 08:12:01 am
content: To estimate the VA rating one could measure the ohmic resistance. Most of the loss at nominal load is from this resistance. There are some tables how much loss a transformer of the given size can tolerate. This also depends on the temperature you want to run it. So the VA rating is not so much a number than is accurately fixed, more like a VA rating versus temperature curve. The standard rating in usually a given temperature rise.Another way would be looking at catalog data from similar transformers. Especially with ring core, there is not that much to make different with the copper. It would be only the temperature rating that can make some difference. The 125 C look more like at the lower end.The thermal fuse is usually one time. Self resetting fuses are rare with transformers - maybe useful for halogen lightning.
Best in circuit IC tester please recommend - Page 1
Forum section: electronics / projects

author: Abdoon
author_rank: Newbie
timestamp: April 14, 2016, 06:59:55 pm
content: I have been searching the internet for the best in circuite IC testers for couple of weeks! all fingers pointed to the ABI 8000 plus, however, it is madly expensive by all means!Would you please recommend a similar device that is capable of testing analog and digital ICs in circuit, fault locator, short locator, oscilloscope and other functions that the ABI system has. Or if you can recommend different devices that can do its work, especially for the in circuit IC tester.Thank you in advanced.

author: mailmad
author_rank: Newbie
timestamp: December 07, 2018, 12:44:09 pm
content: Check this one:https://neatmarine.blogspot.com/2018/11/mi.htmlI have found it in ebay for 1/3 of the price of Abi device you mention.Work somehow in semiautomatic method.Check both analog (opamps), and digital (gates, counters, etc) ICs.Have also a really powerful VI signature tester which helps me a lot for 2-3 pins componentsHave additionaly tenths of other functions not useful for me, even a built in dual channel oscilloscope.Ι distinguish the built-in RS485 reader, which is also useful for my job to check a such network on-site. Not forgot to tell you is portable, and can work with an external power bank!
Best LED/light to show up dust on surfaces? - Page 1
Forum section: electronics / projects

author: victorhooi
author_rank: Regular Contributor
timestamp: April 15, 2023, 08:29:33 am
content: Hi,Does anybody know the best types/wavenlengths of LEDs (or general lights) for showing up dust for visual inspection? (This is for a home environment).I did see a company called X-loupe is meant to have specific lights for showing up dust in a cleanroom environment:https://www.x-loupe.com/caseA09list.htmlHowever, I assume they're ridiculously expensive, and they also seem more designed for forensics/camera usage - whereas I just want a light I can wave around, and show up dust particles easily.I know newer Dyson vacuum cleaners have a small green LED/laser they shine in front of the head - but I'm wondering if that's the best wavelength or not.Has anybody done something like this, or looked into it?Thanks,Victor

author: DC1MC
author_rank: Super Contributor
timestamp: April 15, 2023, 08:50:59 am
content: Your best bet are HDD platter inspection lights, they are all green lights at a wavelength where the eye is most sensible, they're usually used in the dark.https://www.amazon.com/gp/product/B01HBR4OZQ/Cheers,DC1Mc

author: inse
author_rank: Super Contributor
timestamp: April 15, 2023, 09:22:44 am
content: Are you thinking of this Dyson commercial?
Best linear regulator IC for a 5 volt 1 amp supply - Page 1
Forum section: electronics / projects

author: SharpEars
author_rank: Unknown
timestamp: October 21, 2014, 07:16:08 pm
content: What are the best choices for linear regulator ICs that can put out a fixed 5 volt 1 amp output with a low part count? Things I am interested in are low (ripple) noise, short circuit protection and if possible more output current than 1 amp (e.g., 5 amps). Cost isnota factor.In other words, what's much better than the ancient 7805?

author: SeanB
author_rank: Super Contributor
timestamp: October 21, 2014, 07:26:11 pm
content: How about 10A from LT? LT1038 or the venerable LM396.http://cds.linear.com/docs/en/datasheet/1038fa.pdfhttp://offer-shem.narod.ru/data/lm/lm196.pdfOr if you want something more modern ( or at least stil likely in production), LT has a LDO for you.http://cds.linear.com/docs/en/datasheet/158125fa.pdf

author: SharpEars
author_rank: Unknown
timestamp: October 21, 2014, 07:50:34 pm
content: Quote from: SeanB on October 21, 2014, 07:26:11 pmA lot of this stuff is obsolete or has been replaced. Isn't there a good precise low-noise modern linear regulator?

author: SeanB
author_rank: Super Contributor
timestamp: October 21, 2014, 08:37:59 pm
content: Google linear regulator 5V 10A and choose, these were the top few and the LT part might still be available. You probably will get lower current ones though, those were popular when Intel introduced the Pentium which needed low core voltages and you could make them off the 5V rail with linear regulators without too much heat.

author: rsjsouza
author_rank: Super Contributor
timestamp: October 21, 2014, 08:39:30 pm
content: I am familiar with NSC and TI parts (now the same thing).Around 1A I have used the 5.0V fixed (TPS76750/TPS76850) and adjustable (TPS76701/TPS76801) - these are SMD only.In TO220 and more than 1A I know the LM108x series: theLM1084at 5A,LM1085at 3A andLM1086at 1,5A.

author: Marco
author_rank: Super Contributor
timestamp: October 21, 2014, 10:34:44 pm
content: Slightly less than 1A, but adm7150 is the low noise/ripple king of LDOs I think.

author: mariush
author_rank: Super Contributor
timestamp: October 22, 2014, 03:49:32 am
content: 1117 can do 0.8 - 1.2A (depends on manufacturer and package type)7805 can do 1 - 1.5ALT1085 can do 3ALT1084 can do 5ALT1083 can do 7.5AReplace LT with something else (LM for example) to get similar chip from other manufacturer. These three can also be safely paralleled to get more current.LM317 the classic adjustable linear regulator... can configure to output 5v and 1.5-2AThese I used... lots of other linear regulators that look good in the datasheet.
Best method for multi-directional high voltage, high frequency switching  - Page 1
Forum section: electronics / projects

author: willPowell
author_rank: Contributor
timestamp: December 14, 2021, 12:11:13 pm
content: Hi everyone,I am trying to:Send voltage across 3 loads (around 10kΩ each), one after the other, at around 30V.Current can be sent in both directions, since the power supply will be switching polarity (anode switches to cathode, cathode switches to anode dependent on DAC).Ideally switching between the 3 loads at around 1kHz or more.Here is the design I came up with:Where the power supply will switch polarity. The square waves were controlled by a microcontroller at 3.3V to the gate, with a pull down.Unfortunately this only worked properly in one direction - the other direction only turned on to around 2V.I believe this is due to as the mosfet turns on, the source voltage starts to increase to 30V but the gate is only at 3.3V (so the gate source voltage is less than the threshold) and the mosfet only turns on partially.I was thinking of gate drivers but unsure if that would fully turn on the mosfet when the anode/cathode voltage gets to 30V. Solid state relays could work but does not have quick enough switching.Of course if it were only in one direction I would use a low-side mosfet, so the voltage drop across the load is before the drain/source.Any ideas of a method that would work in both directions?Please keep it in layman's terms/with schematics as I don't have an excellent understanding of Mosfets.Thanks,Will

author: strawberry
author_rank: Super Contributor
timestamp: December 14, 2021, 02:28:21 pm
content: VOR2142 optically isolated solid-state relayCD4052

author: willPowell
author_rank: Contributor
timestamp: December 14, 2021, 03:06:02 pm
content: This looks like the perfect device. Did not realise you could find such fast switching solid state relays!
Best microphone for getting silent noises made by electronic? - Page 1
Forum section: electronics / projects

author: Miyuki
author_rank: Frequent Contributor
timestamp: March 26, 2021, 07:46:35 pm
content: Hi folks.I want to ask. I need a way to measure silent sounds what a small percentage of people hear and some cant tolerate.It looks like mems microphone will be the best solution as it can work well at almost any frequency from 20hz to ultrasound range

author: coppercone2
author_rank: Super Contributor
timestamp: March 26, 2021, 08:08:29 pm
content: I made a mems microphone on a stick , get one with an amplifier built in, glue it to the tip of a skewer, put a filter cap in the end and run 2 twisted pairs to it, zip tie, cover with glue and heat shrink. I put the braid over it and covered the top with conductive epoxy to for some kind of shielding
Best practice for anchoring a wire - Page 1
Forum section: electronics / projects

author: Involute
author_rank: Contributor
timestamp: October 27, 2020, 01:03:23 am
content: I'm modifying a Pelican case to house a video switcher and monitor (a more refined version of this:https://youtu.be/I9qHchu2m7Y). Most of the wiring will run beneath a sheet of acrylic sitting on four standoffs in the bottom of the case. Some of the wires will pass from the bottom to the top (to connect to the display) at the edge of the acrylic near the hinge. Since these wires will be exposed, there will always be the chance something will snag on them, or someone may decide to give them a good yank for no reason. What's the proper way to anchor them so a tug won't stress the connections at the other end?I thought of wrapping them around a standoff and then cinching then inbound and outbound wires with a cable tie, but that feels awfully hacky. I know there are lots of different types of cable clamps, but the ones I'm finding seem better suited to tidying up wire bundles and keeping them from flopping around inside a chassis than "yank isolation," but maybe I'm not finding the right ones.Any tips appreciated.

author: Dabbot
author_rank: Regular Contributor
timestamp: October 27, 2020, 01:13:27 am
content: Grab yourself an assortment of nylon cable clamps.I prefer the 'P Clip' style, which require a screw to fasten, but the stick-on type will also serve you fine for a good while, provided you properly clean the surface.

author: coppercone2
author_rank: Super Contributor
timestamp: October 27, 2020, 03:09:23 am
content: you might need to sand the surface, I did some on varnished wood to run signal cables, and when I just cleaned it with isopropyl alcohol it fell off later, but when I sanded first with like 320 grit sandpaper it stuck for 3 years now
Best practice for building a Flir Lepton breakout. - Page 1
Forum section: electronics / projects

author: jdraughn
author_rank: Regular Contributor
timestamp: December 01, 2015, 01:05:36 pm
content: Hi everyone,I am looking to build my own Flir Lepton breakout board and had a couple of questions. The datasheethttps://files.groupgets.com/lepton/documents/Lepton_Datasheet_PUBLIC%20v125.pdfshows that it needs 3 voltages:VDD 2.8v +/- 3% 16mA maxVDDC 1.2v +/- 5% 110mA maxVDDIO 2.5v to 3.1v 4mA maxCould I run the VDD and VDDIO lines off the same voltage regulator? Neither one uses hardly any current. What if I added some extra capacitance? I noticed the VDD is +/- 3% and am worried about the noise that the VDDIO line could cause - but it's only 4mA, how much could it cause with the right amount of capacitance?I was thinking of using the MPC1700 LDO voltage regulators which are good to at least 200mA, would it be better to run the 1.2v regulator off the outputs from the other regulator/regulators, or give it it's own input - probably using a single LiPo or Li-Ion battery?

author: Paul Price
author_rank: Super Contributor
timestamp: December 01, 2015, 06:29:32 pm
content: Don't try to use just one regulator chip to get these three voltages..chips are just too cheap to worry about.Instead use one LM317 for each of the output voltages and you are in business.There are also low power versions of the LM317 that are SMD that will use less PCB real estate.

author: poorchava
author_rank: Super Contributor
timestamp: December 01, 2015, 06:39:27 pm
content: Unless high input voltage is needed, which is not the case here, I tend to use either a jellybean 1117 or MCP1700-xx. LM317 is nice because it allows over 35V between Vin and Vout which is sometimes needed.Sent from my HTC One M8s using Tapatalk.
Is it necessary to connect both common nodes on a 7 segment display? - Page 1
Forum section: electronics / projects

author: hummusdude
author_rank: Regular Contributor
timestamp: September 26, 2020, 10:36:54 pm
content: I'm driving two seven-segment displays (red) with an couple of 74HC595 shift registers on a pcb for an audio pre-amp. I'm wondering if it's necessary to connect both common pins on the display. It seems like there would be some reason they all have 2 of them...common anode in my case... but I haven't found any explanation online about why it's done this way. One less connection would be preferable if there's no significant difference.

author: Peabody
author_rank: Super Contributor
timestamp: September 27, 2020, 01:09:44 am
content: If you're talking about the two common pins on a single digit, I've always assumed they duplicated the common pin so they would have an even number of pins, and so you could connect the common from either side, which might make layout easier. In any case, you can measure the resistance between the two commons with your meter, and if it's very close to zero ohms, then you should be able to connect just one. Of course a two-digit display will have a separate common for each digit, and they will be driven separately.

author: hummusdude
author_rank: Regular Contributor
timestamp: September 27, 2020, 03:15:43 am
content: That makes sense. The only thing I could come up with is a second common node would increase current capacity but hard to imagine that the pins and connector wires would not be able to handle the low current even if all the LEDs were on at the same time.Thanks for the input!

author: SeanB
author_rank: Super Contributor
timestamp: September 27, 2020, 09:11:59 am
content: Common pin duplication is to allow the displays to be chained together, as you then have a built in jumper to the common in the display, leaving room on a single side board to route traces under the display.

author: hummusdude
author_rank: Regular Contributor
timestamp: September 29, 2020, 03:58:16 am
content: Makes sense. Thanks for explaining!

author: ebclr
author_rank: Super Contributor
timestamp: September 29, 2020, 05:04:00 am
content: Have a better Option than a Bunch of HC595 Titan micro led driver family is cheaper and with more functions, less space , and less Cpu timehttps://datasheet.lcsc.com/szlcsc/1810010215_TM-Shenzhen-Titan-Micro-Elec-TM1623_C80913.pdf
best practices for robust sensor input - Page 1
Forum section: electronics / projects

author: golf32
author_rank: Regular Contributor
timestamp: April 21, 2022, 08:35:12 pm
content: I have a device which needs to read a float sensor which is installed possibly 100 feet away across a field. What's the best practice for designing a robust input protection/sensing circuit for this? I've attached a screenshot of a previous revision. In the new revision I don't have access to a 12v rail, instead only a 24v rail and an isolated 5v rail.I suppose I should add a polyfuse to the rail so it doesn't cripple the rest of the system in case of a short.Do you guys think the transistor is necessary for a microcontroller input? Originally it was moreso for level shifting the 12v signal.edit: forgot to attach schematic...
Best practices for SO-DIMM form factor based daughter card design? - Page 1
Forum section: electronics / projects

author: MarkS
author_rank: Unknown
timestamp: July 02, 2017, 02:10:26 am
content: I am, once again..., restarting my 68000-based retro computer project. One day, before I die, I'll get it done. Anyway, I'll be using the 68030 and 68881 chips that I have and am currently working on the processor/coprocessor daughter card which will be based on the 144-pin SO-DIMM form factor.Since I'm basically creating the design specs on the fly, I want to know if there are generally accepted best practises to follow. I noticed that the pin outs for the SO-DIMM memory modules are like this: Vcc, signal, signal, GND, signal... My thinking was to group all of the Vcc, ground and signal pins together in logical groups. It seemed, well, logical. If it isn't typically done, I figure there must be a good reason, but I cannot for the life of me figure out what it is.Any advice would be appreciated.

author: MarkS
author_rank: Unknown
timestamp: July 02, 2017, 01:53:49 pm
content: If this is the wrong forum, let me know and I'll ask Dave or Simon to move it.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: July 02, 2017, 02:20:22 pm
content: Alternate signal & ground is for signal integrity - minimising loop area & ground impedance.There are also issue like reducing risk of latchup if a module is inserted or removed while power is on, and not smoking anything if a CPU module is plugged into a memory socket, or vice versa.

author: MarkS
author_rank: Unknown
timestamp: July 03, 2017, 02:58:42 am
content: Thank you. I knew there had to be a reason. I have the footprint for the card edge connector made in KiCAD, but couldn't create the schematic symbol until this was cleared up. Much appreciated!
Best Push Button Replacement - Page 1
Forum section: electronics / projects

author: Chet T16
author_rank: Frequent Contributor
timestamp: November 04, 2013, 09:20:40 pm
content: Any suggestions on what would be the best way to implement replacing a push button with something controlled by a micro? Is there something that will act exactly like a small relay but opto-isolated and solid state? I'm thinking of a universal solution that i can just connect up to any device i have here and not worry about polarity or what floating voltages there is.

author: pinkysbrein
author_rank: Contributor
timestamp: November 04, 2013, 10:17:56 pm
content: What's the point in saving 1 minute of thought put into using the right tool for the job, whether it be a FET, a relay or a solid state relay and doing the polarity right? You only have to design it once.Guess you're thinking mostly of solid state relays which can switch both AC and DC, just go to digikey and search for solid state relays with output type AC, DC.

author: Chet T16
author_rank: Frequent Contributor
timestamp: November 04, 2013, 10:57:05 pm
content: It's not about saving the time. It's about being able to have a few of these modules ready to be stuck into different things and knowing that they'll 'just work' regardless of how the button operates

author: Jon86
author_rank: Frequent Contributor
timestamp: November 04, 2013, 11:00:44 pm
content: I think you just answered your own question, opto-isolated? An opto-isolator maybe? Unless you need larger currents...

author: SeanB
author_rank: Super Contributor
timestamp: November 05, 2013, 07:37:59 pm
content: High voltage opto FET driver, High voltage MOSFET and a bridge rectifier in front of it made from Shottky diodes will probably cover most applications. For signal applications the opto fet driver and a lower voltage FET will do without the bridge rectifier, but will be polarity sensitive. If you need the high voltage without the diode block 2 opto fet drivers and 2 high voltage MOSFET devices connected in series with the sources commoned will work.
Best Quality PCB Manufacturer for PCB Front Panels - Page 1
Forum section: electronics / projects

author: MarcusS
author_rank: Regular Contributor
timestamp: July 01, 2019, 01:59:47 pm
content: What is the consensus for the best PCB Manufacturer for PCB front panels.I find I'm getting dust in the solder mask and scratches on some boards when I have tried PCBWay and JLCPCB.I'm aiming for really high quality flawless PCBs in this instance.

author: djacobow
author_rank: Super Contributor
timestamp: July 01, 2019, 04:06:01 pm
content: Following. Also who does the "best" silk. I'm mostly using pcbway and my biggest gripe has been sloppy and poorly registered silkscreen.

author: Ysjoelfir
author_rank: Frequent Contributor
timestamp: July 01, 2019, 04:15:01 pm
content: I prefer to pay a bit more for not having to complain at all, which is why I order my PCBs from Würthwww.wedirekt.com/en/or Ringlerhttps://www.ringler.de.

author: MarcusS
author_rank: Regular Contributor
timestamp: July 03, 2019, 03:35:04 pm
content: I will give wurth and ringler a try. Between the scratches, lumpy soldermask with embedded dust and ordinary silkscreen ive had so far, its been very hard to have a fabulously looking pcb front panel for my projects.

author: Warhawk
author_rank: Frequent Contributor
timestamp: July 03, 2019, 08:10:24 pm
content: Try Aisler.de

author: thinkfat
author_rank: Unknown
timestamp: July 04, 2019, 09:33:12 am
content: Quote from: Warhawk on July 03, 2019, 08:10:24 pmThey only offer a matte green solder mask, though. Artistic choices are somewhat limited therefore.Gesendet von meinem Nokia 6.1 mit Tapatalk

author: martin1454
author_rank: Regular Contributor
timestamp: July 04, 2019, 09:50:41 am
content: Never had any issue withhttps://uk.beta-layout.com/pcb/for prototypes
Best Resources for Inductor/Filter Design - Page 1
Forum section: electronics / projects

author: Glenn0010
author_rank: Regular Contributor
timestamp: January 19, 2023, 02:38:24 pm
content: Hi All,Can anyone point me to books/resources on magnetic design of inductors. I'm specifically looking at 3 phase design. Both differential and common mode inductor design. I'd be looking at trying to make the design of the inductor as small as possible.For example on of the questions I have is: I need a 3 phase differential inductor. Is it possible/ would I get any volumetric advantages to wind 3 differential phases onto one core vs 3 separate inductors?My magnetic design knowledge is a bit limited and I've only once designed "single phase" magnetics.Cheers,GG

author: jonpaul
author_rank: Super Contributor
timestamp: January 20, 2023, 10:40:25 am
content: many text books and CAD exist.You design EMI filters, transients protection or SMPS power magnetics ?can suggest best référence and perhaps SW depending on your project goalsJon

author: Glenn0010
author_rank: Regular Contributor
timestamp: January 21, 2023, 11:18:31 am
content: Hi Jon,I'd be mainly looking at designing a filters for power converters. At the moment I'm specifically after a differential filter (LC sine wave filter), the I'd also be looking at a common mode EMI filter. Looking at voltages of around 400 V and 20 A.Cheers

author: jonpaul
author_rank: Super Contributor
timestamp: January 21, 2023, 12:02:17 pm
content: Rebonjour Cher Glenn, a few questions pleaseYou have a power electronics lab with SA, LISN, sniffer, H probes ?Offline SMPS 240/120V input or output filter?your design is for a DIY, consulting or OEM ? ( one off handmade DIY or for production)Compliance for conducted EMI, safety?SMPS topologies, frequency,?You have any books on EMI compliance and filter design?Using any magnetics CAD, e.g. Intusoft Magnetics Designer?Bon courageJon

author: bidrohini
author_rank: Regular Contributor
timestamp: January 23, 2023, 10:38:21 am
content: You can see this for references too:

author: Terry Bites
author_rank: Super Contributor
timestamp: January 23, 2023, 09:31:52 pm
content: Here's a classic I strained from the intersoup. CRC books are usually solid stuff.www.amazon.co.uk/Transformer-Inductor-Handbook-Electrical-Engineering/dp/1439836876(for a very long preview googlate "ourdev_725050HHOGA4.pdf" but dont involve me )
Best RJ45 Ethernet/TCP-IP to TTL module - Page 1
Forum section: electronics / projects

author: JohanHoltby
author_rank: Contributor
timestamp: January 05, 2020, 09:58:34 am
content: Hi!Previous in my working life I have seen Ethernet to TTL modules which did work great but I can't remember the name. Any one having any good tips for a good working board mounted Ethernet/TCP-IP module?

author: NiHaoMike
author_rank: Super Contributor
timestamp: January 05, 2020, 04:47:04 pm
content: Wiznet is the one used by the official Arduino Ethernet shield.https://www.wiznet.io/product/

author: nctnico
author_rank: Super Contributor
timestamp: January 05, 2020, 07:37:27 pm
content: I second the suggestion for a Wiznet chip. I do recommend though that for any professional product to put the on the PCB itself and not use a module. I'm not impressed by the layout of the module boards I have seen so far. With some care two layers are more than enough to create a good design using one of the WIznet chips.

author: kripton2035
author_rank: Super Contributor
timestamp: January 05, 2020, 07:45:04 pm
content: waveshare ?

author: JohanHoltby
author_rank: Contributor
timestamp: January 05, 2020, 09:47:15 pm
content: Thank you all! I will go with the Wiznet chip. Then I also have the option of just take great inspiration from that layout arduino use. I did find the module I had worked before with: LANTRONIX but they are not low cost....

author: nctnico
author_rank: Super Contributor
timestamp: January 05, 2020, 10:05:32 pm
content: Quote from: JohanHoltby on January 05, 2020, 09:47:15 pmBetter don't. Look at Wiznet's own application notes instead. What is missing on the Arduino shield are TVS diodes and series ferrite beads (10 Ohm@100MHz is a good value) to take care of EMC problems.

author: JohanHoltby
author_rank: Contributor
timestamp: January 06, 2020, 03:41:32 pm
content: Wow thanks for that input it probably saved me a week!
Best software for modeling of Inductive and Capactive Wireless Power Transfer  - Page 1
Forum section: electronics / projects

author: 6E5
author_rank: Regular Contributor
timestamp: March 14, 2014, 07:12:23 am
content: Hello,I want to do some simulations of a inductive and capacitive based wireless transfer system using software. For the inductive system there will be two parallel coils. When one is subjected to a current, I can calculate the transferred power. For the capacitive system, four plates separated by air and when one set of plate is subjected to a voltage, I can measure the capacitively inducted voltage in the other set.What program would you recommend for this. I'm limited to low cost open source solutions. One that I am familiar with and may work is FEMM.Paul
Best spring or clamp connectors from ebay - Page 1
Forum section: electronics / projects

author: Stephen37
author_rank: Contributor
timestamp: December 04, 2016, 04:59:35 pm
content: I am looking for some decent and hopefully cheap terminal blocks for wiring leds for ilumination (no connector will pass more than 100W)Which one of these do you think has the best cost/performance ratio ?Wago 221 clone :ebay linkWago 222 clone : (the same price as the 221 clone)ebay linkChinse spring connector for leds: (twice as cheap as the wago clones)ebay linkDid anyone use any of these and was satisfied with the connection ?

author: SeanB
author_rank: Super Contributor
timestamp: December 04, 2016, 08:10:01 pm
content: Don't buy the cheap one, that plastic cracks after a few months of exposure to UV light, or after it has been warm for a while. The Wago clones ( or better yet the real WAGO ones) will work.I assume you are using them for outdoor lights, and they are running off 115VAC mains. If so then enclose them in a weatherproof box, and use proper cable glands as well to keep them dry.

author: ebclr
author_rank: Super Contributor
timestamp: December 05, 2016, 03:42:09 am
content: I have both, the 1st one is much better, the 2nd one only for wires at least 1.5 mm otherwise trouble ahead
Best Switcher Design Website Does the Design For You? - Page 1
Forum section: electronics / projects

author: LaserSteve
author_rank: Super Contributor
timestamp: February 22, 2024, 04:33:04 pm
content: I need a step down switcher for a Laser Diode Driver board.Simple rule of no voltage overshoot.0-7 volts100 mA to say 5 amps for one design100 mA to 14 amps for the other.Vin is 24VDCThis is to reduce stress across a pass transistor for a modulatable current source.Which semi manufacturer has the best on-line design/calculation software? Preferably with known mass produced inductors?Or should I be looking at the site of an inductor manufacturer?Why yes, I could set down and do some math...However it is so rare I need to design a switcher, that a generic starter design is probably acceptable.Steve

author: voltsandjolts
author_rank: Unknown
timestamp: February 22, 2024, 05:24:36 pm
content: Do you really need output down to 0V?COTS supplies available for down to 3.3Ve.g.https://uk.farnell.com/tdk-lambda/i6a-240-14a-033v-001-r/dc-dc-converter-3-3v-to-24v-14a/dp/2664686

author: LaserSteve
author_rank: Super Contributor
timestamp: February 22, 2024, 08:08:50 pm
content: Lets call it down to 1.8 volts.Trying to keep costs down, hence design it in to the diode driver board.So how is Webench?

author: youngda9
author_rank: Regular Contributor
timestamp: February 22, 2024, 08:42:48 pm
content: Go to linear tech website. Choose your converter type. Narrow down to chips that meet your needs (Vin, Vout, Pout). Each chip will have one or more demo boards that you can purchase. Demo board schematics are available on the website. Demo boards also have already configured LTSpice completed designs that are ready to simulate. This is all downloadable on the website. Edit values in simulation if needed and test per your needs via simulation. Then you have a working design, in simulation, ready to put onto a board and test. Can purchase the demo board if you'd like to test your changes first if there are any of concern.

author: LaserSteve
author_rank: Super Contributor
timestamp: February 24, 2024, 01:46:42 am
content: Thank you, I'll give LT a try..Steve

author: Bud
author_rank: Super Contributor
timestamp: February 24, 2024, 05:18:08 am
content: IC datasheets usually have required formulas to calculate inductor values. It is fairly simple. Just read the datasheet.
Best thermal overload protection for my circuit? - Page 1
Forum section: electronics / projects

author: jonwil
author_rank: Contributor
timestamp: June 16, 2019, 11:43:52 am
content: Can anyone suggest a good part (something I can buy at Jaycar) to add to my circuit to cut power if the ATTiny85 micro starts getting too hot?I think I need some sort of thermistor but I dont know the first thing about thermistorsEDIT: Some sort of over-current protection would also be great (not sure what sort is best for this or how to calculate the value to use)

author: OM222O
author_rank: Frequent Contributor
timestamp: June 16, 2019, 01:39:59 pm
content: You can use a polyfuse for over current. They have positive tempco and as the current passes through them, their resistance increases which means they "trip" since they go really high resistance. Once cooled off, they are back to normal. If you place it near the MCU or if your PCB is small, they can also trip of the ambient gets too hot.If you want to control the attiny temp itself, that's a bit more involved, but my main question would be, how on earth are you heating up the MCU to begin with? If that's happening, you did something wrong in your design.

author: MarkL
author_rank: Unknown
timestamp: June 16, 2019, 03:53:09 pm
content: You haven't described your application in enough detail, but the ATTINY85 has a built-in temperature sensor that you could monitor periodically and shut things down if it's approaching operational limits.