hybridfree/eevblog-posts huggingface dataset:
Fast immersion thermistor - Page 1
Forum section: electronics / projects

author: maxwell3e10
author_rank: Frequent Contributor
timestamp: May 29, 2020, 07:16:20 am
content: I needed a fast temperature sensor for water temperature control and compared a couple of promising thermistor models. I thought I'd share the results here. Vishay NTCAIMME3 is the winner, it has a time constant of 1.1 sec according to my measurements and is quite inexpensive for an encapsulated sensor. Amphenol CR1 is a bare chip coated with water resistant coating. But despite having a much smaller mass, it actually has a slightly slower thermal response.

author: RoGeorge
author_rank: Super Contributor
timestamp: May 29, 2020, 07:28:30 am
content: In my experience, thermocouples were the ones with the lowest thermal inertia.

author: maxwell3e10
author_rank: Frequent Contributor
timestamp: May 29, 2020, 10:31:36 pm
content: It's hard to get mK temperature resolution with a thermocouple. And it would still need to be protected from corrosion in a liquid.

author: thm_w
author_rank: Super Contributor
timestamp: May 30, 2020, 12:12:45 am
content: Yeah bare thermocouple will easily corrode in water causing some unusual readings.For some reason I used to think the normal thermocouples you get with a DMM could be immersed.
Fast oscilloscope front-end circuitry - Page 1
Forum section: electronics / projects

author: allanw
author_rank: Frequent Contributor
timestamp: December 13, 2010, 09:20:03 am
content: I'm making a board using this ADC:ADC11DV200. It is a dual 200MS/s, 900 MHz analog bandwidth, 11-bit ADC. At $45 in single quantities from Digikey, it has the best price/performance ratio (next up is a single 500MS/s, 8-bit ADC at $55).I thought it'd be nice to leave the input analog bandwidth as wide as possible to allow fast equivalent time sampling.I'm planning on using this PGA:LMH6518It has a bandwidth of 900MHz, and adjustable gain up to around 40dB. It even has programmable bandwidth limits of 20, 100, 200, 350, 650, 750MHz. I do realize the total system bandwidth is reduced to 600MHz due to the cascade of -3dB 900MHz bandwidths.The PGA's datasheet has a bunch of oscilloscope input circuits, but they only go up to around 350MHz. I'm planning on taking page 28's JFET LNA, and replacing the JFET and other circuitry with higher bandwidth RF FET's. I'll also need to make a basic input attenuator. Does anyone with experience have some advice or some proven circuits to use? This is going on a 4-layer board with only a single +5V supply.edit: found some interesting reading here:http://books.google.com/books?id=SPwqg7qpFWUC&pg=PA66&lpg=PA66&dq=oscilloscope+front+end&source=bl&ots=_4gV30o6Gx&sig=6p0k3pgmEJxfnTOmf03HHcKZmew&hl=en&ei=CPMFTajfFMH_lgf0xJz_CA&sa=X&oi=book_result&ct=result&resnum=2&ved=0CBwQ6AEwATgo#v=onepage&q=oscilloscope%20front%20end&f=false. Seems difficult

author: NiHaoMike
author_rank: Super Contributor
timestamp: December 13, 2010, 04:17:07 pm
content: It's cheaper to just buy a good oscilloscope.

author: Mechatrommer
author_rank: Super Contributor
timestamp: December 13, 2010, 05:41:23 pm
content: i want to place an order! can i? 900MHz DSO?hope the price will be the same as ds1052e of even alot less!

author: allanw
author_rank: Frequent Contributor
timestamp: December 13, 2010, 07:00:40 pm
content: I have a good DSO alreadyThe cascaded bandwidth of two 900MHz systems is only about 650MHz. Also, I've learned that the amplifier peaks at 900MHz and only has a good flat frequency response if its bandwidth limit is 650MHz. So that probably limits the bandwidth to around 500MHz. And keep in mind it'll only be 200MS/s, so it'll only be useful at high bandwidths if the signal is repetitive.The most difficult part is the input circuitry at that bandwidths. And I'm not making a fully featured and protected scope front-end, just a basic one that'll only have one or two attenuation factors.

author: NiHaoMike
author_rank: Super Contributor
timestamp: December 13, 2010, 10:50:42 pm
content: Just have a standard 50 ohm input (or 75 ohm) since standard passive oscilloscope probes are not going to work very well at 500MHz. Then it's just a matter of using standard broadband RF design. Ask an experienced amateur radio engineer for that advice.
Fast recovery diode comparison Siemens byp102 versus Vishay  e5px6012L - Page 1
Forum section: electronics / projects

author: zupta82
author_rank: Regular Contributor
timestamp: January 04, 2021, 02:14:59 am
content: I was wondering if using the Vishay equivalent compared to Siemens in a plasma cutter would work, I know this might be sounding like an eluding to a previous post, I hope I don’t get people angry. I want to learn from my mistakes. I previously installed the Vishay replacement and now won’t get any cutting power just a pilot arc sputtering. I kind of bought the replacements impulsively.https://www.digchip.com/datasheets/download_datasheet.php?id=202745&part-number=BYP102https://www.vishay.com/docs/96479/vs-e5px6012l-n3.pdf

author: zupta82
author_rank: Regular Contributor
timestamp: January 04, 2021, 02:30:16 am
content: This was the closest I could find

author: zupta82
author_rank: Regular Contributor
timestamp: January 04, 2021, 03:34:11 am
content: Ok I think I figured this out. The fred rectifiers that I used have a much faster reverse recovery time. I should of looked at the data sheet closer. I guess 30nS vs 130nS has to make a big difference. I also did notice the pilot arc is more brighter and intense. I’m guessing a stronger corona discharge coupled with higher oomph (more current to burn metal).

author: zupta82
author_rank: Regular Contributor
timestamp: January 05, 2021, 03:21:44 am
content: I guess a more meaningful question would be what is a common use for higher reverse recovery diodes. I’m guessing they are often used circuits where high current and high frequency is being switched??
Fast simultaneous sampling for reasonable price - Page 1
Forum section: electronics / projects

author: poorchava
author_rank: Super Contributor
timestamp: November 24, 2017, 08:21:26 am
content: W're beggining a project, which needs to sample 3 signals simultaneously quite fast (~500k-1Msps) at resolution higher than standard 12-bits found in most microcontrollers. Start of sampling must be really simultaneous. <10ns difference is desired. We also need to process that data which involves standard dsp stuff (fft and such). In the previous version of the product we used a 120Mhz CM4 microcontroller and it has proven to be significantly too slow for what we anted to do. We estimate the the new version of the algorithm will require about 500k-1M of RAM. We'd ideally like the design to be implementable on a standard 4-layer PCB. 6-layer is a possibility if we are absolutely forced to, but more layers, HDI or other exotic processes are unacceptable.Now it seems like the new STM32H7 family from ST fits the bill perfectly. Lots of flash, whopping 1MB of SRAM, 850DMIPS/400MHz, 3 separate 16-bit ADCs with hardware oversampling and differential input capability (although even in diff mode ENOB is ~13.5). There are two problems with that: first of all it doesn't seem like H7s will be available in retail any time soon. We are currently trying to get a couple of devboards or even bare parts themselves through our suppliers, but it doesn't look promising. Another thing is that H7 has shitload of stuff we don't need and ideally wouldn't want to pay for (we only need the ADC, 10 mbit serial port and shitload of processing power, ok maybe an external memory controler will come in handy too).Can you think of another solution to that problem other than a microcontroller with fast sampling integrated ADCs? We've looked into solutions like standalone s/h chips, implementing a discrete s/h using multiplexers, external adc with parallel sampling functionality, parallel bus adcs, fpgas and such, but anything we come up with immediately turns out to be far more expensive than the H7 approach. Implementing entire thing in an FPGA is gonna require massively expensive HW (it onvolves 4k point F32 ffts) and loads of development time. The only somewhat reasonable solution that came up is to use 3 independent ADCs hooked up to a cheap FPGA which then connects to a powerful uC over SRAM interface, but it still turns out to be more expensive than an H7 and obviously more complicated than the H7 variant from software development standpoint.Perhaps there is some obscure family of microcontrollers that would fit the bill?
Fast switching and how to reduce EMI - Page 1
Forum section: electronics / projects

author: Johannsen
author_rank: Regular Contributor
timestamp: January 28, 2021, 11:05:41 am
content: Hi,I came across this boardhttps://raw.githubusercontent.com/gordonthree/pca9633/master/pca9633-proto.pngwhere a mosfet is connected to a driver and a controller to produce a 97kHz pwm for drinving leds. Obviously that's working well but I read some articles about LED drivers from manufactures like TI that they're doing some hard work with inductors etc to reduce EMI. Wouldn't that circuit in the link produce a lot of EMI without any filters? and how could that be improved?

author: penfold
author_rank: Frequent Contributor
timestamp: January 28, 2021, 11:52:17 am
content: Without any filtering it certainly has the potential to cause problems.The actual radiated electric or magnetic fields are dependant largely on the geometry of the total circuit and the di/dt and dv/dt. If it were driving an LED strip then the current return path could be reasonably close to the outward path and it'd probably be acceptable, if the LEDs were arranged like a string of Christmas tree lights then there'd be a considerably greater area probably causing a problem.The TI app notes are generally focused on pretty high performance/efficiency/miniature circuits that feature very fast MOSFET switching times and generally have high di/dt and dv/dt, resulting in high numbers of 'significant' harmonics at higher frequencies (only really troublesome towards the MHz)... these would need controlling with some filtering to stop them getting as far as the string of LEDs where they can be easily radiated.It may well be that the circuit in your question isn't switching particularly fast (talking the squareness of the edges not the frequency of the square wave) at all and not creating any nasty harmonics and the LED string to which its connected doesn't radiate noise particularly well, then you're good.If it turns out to be causing you issues then the first port of call is putting some inductance in series with the LEDs, then some capacitance to keep the voltage swing low, keeping the total loop area of your current flow small etc

author: Johannsen
author_rank: Regular Contributor
timestamp: January 28, 2021, 09:51:14 pm
content: Ok thanks for your explanation. I expect the LEDs to be next to the driver. Maybe a few cm cable in between.
fast switching of high power LED'S - Page 1
Forum section: electronics / projects

author: sagnikbasu
author_rank: Contributor
timestamp: January 22, 2017, 08:50:31 am
content: I am testing some high power leds ( as given in this link :http://www.ebay.in/itm/112103955540?aff_source=Sok-Goog) for visible light communication.The problem with this is that the switch off time for this led is some 10-15 seconds , which is too long even for sending data using PWM. For switching I am using a N-Channel Mosfet.Is there any way I can improve the LED switch off speed ?Is the mosfet push pull configuration ( N-channel + P-channel ) helpful in this case?Thanks for your help.

author: tpowell1830
author_rank: Frequent Contributor
timestamp: January 22, 2017, 09:25:01 am
content: Perhaps if you link to the specifications to the LED device to find the switching speed, and a sketch of your driving circuit, you may get advice. There is no way to tell from your comments.PEACE===>T

author: mmagin
author_rank: Frequent Contributor
timestamp: January 22, 2017, 11:34:19 am
content: White LEDs use a phosphor in front of a blue LED. You're not going to make that fast electronically.

author: MK14
author_rank: Super Contributor
timestamp: January 22, 2017, 11:50:53 am
content: Quote from: sagnikbasu on January 22, 2017, 08:50:31 amIs that being used in a car courtesy light, and the 10 to 15 seconds minimum on time, is because the courtesy light delay circuit, is keeping it on for that time, after you close the door (switch it off) ?If so, you have probably wired it up wrong as regards the car. I.e. You need a more direct connection to the lamp/Led, so the courtesy unit can no longer force it on for the 10 to 15 seconds. Then it should work a lot faster.If I'm completely way off here, it is because of aLACKof detailed explanation of the problem.

author: Seekonk
author_rank: Super Contributor
timestamp: January 22, 2017, 02:06:13 pm
content: I've never seen any LED that wasn't quite fast. I've strobed them at double their voltage. they can produce light at very little current. I suspect the driver circuit.

author: Fungus
author_rank: Super Contributor
timestamp: January 22, 2017, 07:37:47 pm
content: 10-15 seconds is done by the car,notthe LED.
Fast Transient Bursts & 50 Hz Capacitive Couple Noise - Page 1
Forum section: electronics / projects

author: Ashraf Almubarak
author_rank: Contributor
timestamp: January 18, 2018, 09:18:31 am
content: I have a circuit that measure the 50Hz AC voltage and current through potential divider and shunt resistor respectively. It do that through inverting amplifier using OPAMPs. It has some DC blocking capacitors and DC biasing in the positive input of the OPAMP as seen in the picture below.I have made a polygon cutout (The polygon is in the bottom layer) under the inverting input of the differential amplifier as suggested by TI OPAMP for everyone design note.Still I have a 50Hz capacitive coupled noise of 32mV in the output of the opamp. And I would like to make it smaller.Another thing to add is when performing the fast transient bursts test of 2.5 KHz 4kV. The noise coupled has very large peaks that affect the measure circuit. Although I have a MOV 20D471K in the input of the circuit. The layout is shown in the picture below.So if the layout is poor?Or I have to reduce the resistance further more?Or there is another suggestion?
Fastest four-pin optocoupler - Page 1
Forum section: electronics / projects

author: Gall
author_rank: Frequent Contributor
timestamp: September 04, 2011, 07:51:59 pm
content: Hi,I wonder if they are fast optocouplers in 4-pin DIP packages. I know PC817 and equivalents, they are 4 us typ. I'd like to look at dual, triple and quad units too as long as they are pin compatible with 4-pin units stacked together (like PC827? PC837 etc.)It's all about pin compatibility (direct replacement in someone's else bad design). I already know many parts for indirect replacement, no, I do not need more

author: jakeypoo
author_rank: Regular Contributor
timestamp: September 09, 2011, 01:30:34 am
content: You can lower the load resistance to increase response time as long as you don't go over recommended collector current.If you want good performance I would stay with Sharp. PC813 series (pc823/pc843 [2/4 channel]) are quite good.Obviously these are only pin compatible if the 4pin DIPs are spaced properly next to each other.
Fastest SOIC FET Driver - Page 1
Forum section: electronics / projects

author: stretchyman
author_rank: Regular Contributor
timestamp: May 30, 2024, 07:35:04 am
content: Hi ALL.My current project is a class E HF A.M. transmitter and am trying to get the switching frequency above 15MHz.Have been using 6nC GaN FET O/P devices and NCP81074 drivers without too much trouble, altho' drivers do get a bit toasty!My new goal is 20MHz with 10nC (approx 1nF Ctot) GaN (Nexperia TO247's) and am looking into the plethora of SOIC drivers as there are many to choose from and wonder (hope) that someone out there may have found the fastest one available?Specs vary with rise times quoted from different manufactures into varying loads (1nf, 1.8nF, 10nF) with no chart as to rise times vs gate charge, so not easy to compare.Other than being SOIC8 it will have to have a solderable pad on the underside, some of the smaller packages use this already but SOIC8 is very easy to use for me as it's not too small.I'm thinking of trying ISL89163FBEAZ as it's looks good but rise time is slow compared to NCP81074 but this is into 10nF vs 1.8nF for the NCP driver.Anyone, any thoughts?Your help and advice would be much appreciated!Best RegardsStretchy.

author: uer166
author_rank: Super Contributor
timestamp: May 30, 2024, 07:48:58 am
content: At those frequencies it's likely not possible to do separate gate driving well, better look at on-die drivers with FET such ashttps://epc-co.com/epc/products/gan-fets-and-ics/epc21601.

author: stretchyman
author_rank: Regular Contributor
timestamp: May 30, 2024, 08:41:36 am
content: Thanks for the reply.However as stated I need a SOIC 8 device ideally and am looking for the fastest available.With all the varying spec out there someone must have tried a load of them to find the best one.The devices you have shown look amazing but beyond my ability to work with.Appreciate the help.RegardsStretchy
Fastest Tayloe Mixer with off the shelf parts - Page 1
Forum section: electronics / projects

author: ezalys
author_rank: Frequent Contributor
timestamp: September 09, 2023, 07:02:09 pm
content: What's the fastest Tayloe detector anyone has seen made with off the shelf parts? I guess if you want sensitivity at 50 MHz it has to be clocked at 200 MHz -- is that doable? Can you go faster?

author: mawyatt
author_rank: Super Contributor
timestamp: September 09, 2023, 09:04:32 pm
content: Don't know about off-the-shelf components, but an extension of the Tayloe Detector called the PolyPhase Mixer, or N-Path Mixer, extended performance into the Microwave regions with moderately high speed CMOS devices. These mixers are now finding their way into high performance SDRs and other applications.Think you'll find these threads interesting. Be sure to follow up the IEEE articles mentioned, they are quite involved, but highly informative, and revel how these mixers broke the rules of conventional mixer theory. We were fortunate enough to be involved from the early theoretical/developmental stages of these new mixers and can personally verify their amazing performance.https://www.eevblog.com/forum/rf-microwave/polyphase-or-n-path-mixer/msg3381802/#msg3381802https://www.eevblog.com/forum/rf-microwave/electrically-tunable-crystal-band-pass-filters/msg4901588/#msg4901588https://www.eevblog.com/forum/rf-microwave/questions-about-tayloe-detector/msg4323943/#msg4323943Best,
FastHenry integration in Blender  - Page 1
Forum section: electronics / projects

author: Schottky
author_rank: Regular Contributor
timestamp: June 07, 2024, 03:13:14 pm
content: Hi, I've been working on a python addon which allows you to run FastHenry directly in Blender, you can use the power of Blender to effortlessly create any curve object and then call FastHenry to simulate the resistance and inductance.This demo video shows how you can calculate the resistance and inductance of a bond wire in a power module. You can experiement with different shapes and curvatures and see how the inductance changes. Furthermore you can control the radius with geomotry nodes! This will be very useful in determining the parasitics in power modules and power electronics, espcially GaN and SiC, and to aid to optmising a design to minimise these parasitcs.Also, you can combine this with ElectroMag Nodes to then visualise the magnetic fields! This addon will be released over the next couple of days, and will be publishing more demos

author: nimish
author_rank: Regular Contributor
timestamp: June 07, 2024, 10:51:50 pm
content: Awesome. Integration with pcb2blender and a tutorial would be greatly appreciated

author: Schottky
author_rank: Regular Contributor
timestamp: July 10, 2024, 04:03:45 pm
content: Here is a new update video, I can now include mutual inductances, also developed a simple UI inside Blender to display results and to indicate the coupled objects, red box shows active object and yellow box shows coupled object
faston connector tarnish  - Page 1
Forum section: electronics / projects

author: aniket
author_rank: Contributor
timestamp: March 06, 2020, 04:14:04 pm
content: Hi Guys ,I have started using 6.3mm Faston connector in my diy amps for sometime as they provide easy assemble in tight spaces . I made some amps for my frnds 6 months back and one of the amp came back due to a blown mains fuse.Then I discovered that the all of the faston connectors in the amp board has tarnished some had bluish green coating on them some had a blackish residue , when new the connectors where shiny mostly silver coating not sure though.I want to change the these connectors , I have two options either i go with TIN plated connectors or Silver coated connectors which should I choose , is there a way to check the connectors aging ?Pictures of tarnish connectors below

author: Tomorokoshi
author_rank: Super Contributor
timestamp: March 06, 2020, 05:58:36 pm
content: Can you get some clear pictures of the bottom of the board in IMG_20200304_003956(1).jpg?

author: David Hess
author_rank: Super Contributor
timestamp: March 07, 2020, 12:37:56 am
content: If the connectors are tight, then tarnish should not be a problem unless it indicates ongoing corrosion.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: March 07, 2020, 01:29:56 am
content: Better to keep them well away from moisture, condensation, humidity, whatever. Salt spray especially, and the color of corrosion on the one looks like some salty residue was likely involved.You may find a tighter, closed or even sealed, connector is better than open Fast-Ons. If the chassis can be made in such a way that drips don't enter, that's something. If airflow is mandatory, perhaps a fan and filter could be fitted, or larger external heatsinks used. There are rubber boots for Fast-Ons, but they don't really seal; might help a little.All about how much cost-reliability tradeoff your application has available.Tim

author: Vovk_Z
author_rank: Super Contributor
timestamp: March 09, 2020, 09:41:20 am
content: It don't look very bad as for me (as I can see on a first photo).Those one on the last photo (green ones) - definitely looks bad.Something eat them. Better to find what it is.I don't know definitely but I think silver-plated ones will have the same problem.

author: wraper
author_rank: Unknown
timestamp: March 09, 2020, 10:15:35 am
content: It's obvious liquid damage and faston connectors are the least you need to worry about. Other connectors and fuse holder have corrosion on them as well and god only knows what is happening under components.
Faston/quick disconnect terminals - Page 1
Forum section: electronics / projects

author: theoldwizard1
author_rank: Regular Contributor
timestamp: October 19, 2019, 01:18:48 am
content: To complete my "repairs kit", I want to purchase some 1/4" (6mm) female faston/quick disconnect terminals, but I am picky. They have to have the following characteristicstin coated copperun-insulatedfull barrelIt should look similar to this ring terminal
Fat-pin TDA7292 Prototyping - Page 1
Forum section: electronics / projects

author: Jon86
author_rank: Frequent Contributor
timestamp: October 22, 2013, 05:50:38 am
content: I've just bought a TDA7292 40+40W Audio amp from ST, and it comes in this quite easy to use Multiwatt-11 package, the only problem is that the pins are too fat to put through a stripboard...I don't know if there's any I can get that have larger holes, but there's no way I can print my own PCBs so that's out the question. Any ideas? Adapters maybe?Thanks

author: homebrew
author_rank: Frequent Contributor
timestamp: October 22, 2013, 07:38:35 am
content: Why not taking a drill bit (1.0 mm) and drill from bottom to top (to avoid ripping off the pad)?Or maybe I don't understand the question right!?

author: peter.mitchell
author_rank: Super Contributor
timestamp: October 22, 2013, 08:17:09 am
content: Quote from: Jon86 on October 22, 2013, 05:50:38 amGot any non-machined ic sockets? I use them. up to quite large legs fit in them.

author: Jon86
author_rank: Frequent Contributor
timestamp: October 22, 2013, 08:21:48 am
content: Quote from: homebrew on October 22, 2013, 07:38:35 amThat could work, but I'd probably cut the trace in the process...

author: Jon86
author_rank: Frequent Contributor
timestamp: October 22, 2013, 08:30:50 am
content: Quote from: peter.mitchell on October 22, 2013, 08:17:09 amAh that could work, I don't have any but I could order some...

author: SeanB
author_rank: Super Contributor
timestamp: October 22, 2013, 07:39:57 pm
content: Take 2 boards and place back to back so the traces are on the visible side. then place the sandwich between the leg rows and solder to the legs. that way you have a breakout row on each side to solder to the veroboard via short wires.
FAT32 Long filename license - Page 1
Forum section: electronics / projects

author: Koen
author_rank: Frequent Contributor
timestamp: January 25, 2016, 10:08:29 pm
content: Hello,as I understand it after reading about the TomTom case, FAT32 "Long filename" is still subject to licensing by Microsoft ? Is this correct ?Thank you very much,Koen

author: Len
author_rank: Frequent Contributor
timestamp: January 25, 2016, 10:53:21 pm
content: The issue is complicated, but as far as I can tell, yes, the FAT32 long name patent is still valid in the USA (but not in Germany). I don't know if Microsoft has a simple way for you or me to license it. Linux gets around the patent by not completely supporting the long name feature in FAT32.

author: Delta
author_rank: Super Contributor
timestamp: January 26, 2016, 12:13:34 am
content: WTMFF? (That's a MF added to my WTF!)Microsoft were granted a patent for pretty much "storing two filenames on a disk"Wow!

author: Len
author_rank: Frequent Contributor
timestamp: January 26, 2016, 12:15:31 am
content: Quote from: Delta on January 26, 2016, 12:13:34 amNo, they were granted a patent for a way of storing both long & short filenames for each file, in a way that neither you nor anyone else had done before.

author: Delta
author_rank: Super Contributor
timestamp: January 26, 2016, 12:34:30 am
content: Quote from: Len on January 26, 2016, 12:15:31 amPfffft, I'd been doing it that way for years! And storing a medium length filename too, just for a laugh...

author: amyk
author_rank: Super Contributor
timestamp: January 26, 2016, 11:05:58 am
content: Quote from: Len on January 25, 2016, 10:53:21 pm... and everyone else just doesn't give a toss what M$ thinks. Linux vfat driver supports long filenames.

author: newbrain
author_rank: Super Contributor
timestamp: January 26, 2016, 12:06:15 pm
content: Quote from: amyk on January 26, 2016, 11:05:58 amNot completely true, Linux community cared enough to have the vfat driver patched specifically to avoid infringing the two Microsoft patents about long file names in FAT.The trick is that either a long file name or a short one is stored for a file, never both at the same time (with some compatibility limitations).Seehttps://lkml.org/lkml/2009/6/26/314for the FAQ.Whether this kind of patent should or should not be granted is another story, but since they are in place (mostly US), better safe than sorry.

author: Zero999
author_rank: Super Contributor
timestamp: January 26, 2016, 12:25:17 pm
content: Doesn't the patent expire soon if it hasn't already expired?

author: newbrain
author_rank: Super Contributor
timestamp: January 26, 2016, 01:11:46 pm
content: Quote from: Hero999 on January 26, 2016, 12:25:17 pmYes, not easy to understand if you are not an expert in the field (and I'm surely not!) but either they both expired in 2013 or one did in 2015 and one is going to in 2016...

author: Zero999
author_rank: Super Contributor
timestamp: January 27, 2016, 12:20:41 pm
content: No, I'm not an expert but going by the release dates of Windows 95/98, it's likely the patents would have expired or soon will.
Faulty op-amp? - Page 1
Forum section: electronics / projects

author: JoeP
author_rank: Contributor
timestamp: March 01, 2019, 11:04:00 pm
content: I'm trying to use an op-amp in an amplifier circuit (the LM324N), but it doesn't seem to be working properly. From a 5V power supply, I measured the non-inverting input at 2.5V, the inverting input at 0.8V and the output at 3.9V. Shouldn't the output be at the full 5V? I haven't used op-amps much, so it might just be a simple mistake with the circuit, which I'll attach later.

author: radix
author_rank: Contributor
timestamp: March 01, 2019, 11:11:26 pm
content: The ancient LM324 can't get its output near the rails. If you look at the datasheet, you'll see that the output swing is specified at approximately 2 V less than the supply voltages. Use a better opamp with a rail to rail output.

author: Siwastaja
author_rank: Super Contributor
timestamp: March 02, 2019, 01:12:26 pm
content: Or, increase Vcc.
Favorite connector for I/O board - Page 1
Forum section: electronics / projects

author: nctnico
author_rank: Super Contributor
timestamp: November 06, 2013, 03:22:32 pm
content: I need some help on a decission...I'm contemplating designing a programmable box or board which has 32 to 64 analog inputs and outputs for controlling test setups etc. So up to 128 connections have to be made. I'm not quite sure what kind of connector I should put on it. Sub-D, ribbon cable or screwless clamps are on the short list.

author: minime72706
author_rank: Frequent Contributor
timestamp: November 06, 2013, 05:18:02 pm
content: Would you dedicate certain connectors for analog inputs and some for outputs or would this be configurable? Do you plan to drive much of any power through these connectors?

author: casinada
author_rank: Frequent Contributor
timestamp: November 06, 2013, 05:23:05 pm
content: Do you need to be able to connect them at the same time or individually?https://www.phoenixcontact.com/online/portal/us?1dmy&urile=wcm%3apath%3a/usen/web/main/products/subcategory_pages/PCB_terminal_blocks_P-20-04/662f4561-9547-4cf3-89a0-0044c5a658aaThey have Male female configurations that come really handy as you can see on the bottom of the page:http://www.akshatautomation.com/phoenix_pcb_connectors.htmlIt was easier to find the connectors before.I wish everybody had product finder like this:https://www.mill-max.com/product_finder/1

author: Niklas
author_rank: Frequent Contributor
timestamp: November 06, 2013, 05:24:35 pm
content: There are a few questions you have to ask yourself before selecting a connector:- Is it a on time setup or reconfiguration on the fly?Screw terminals might be easier than soldered wires to reconfigure- Just one pcb to test or series production?Series production must be faster to connect/disconnect- How many cycles do you expect to connect/reconnect?Connection quality degrades with each mating cycle.- Signal integrity, need for a physical split up of different signals?- Available space?A larger connector is usually to connect

author: nctnico
author_rank: Super Contributor
timestamp: November 06, 2013, 08:40:57 pm
content: The signals will be low frequency analog (-10V to +10V at a few mA tops). For now the spring clamp connectors seem a good option. I've used sub-D on an earlier 'version' and soldering the wires took quite some work.The number of mating cycles depends on the application. I guess some boards will be used in a number of test setups and some will remain in one setup forever.

author: marshallh
author_rank: Unknown
timestamp: November 07, 2013, 03:05:32 am
content: pci-e x16 edge mount connector

author: calexanian
author_rank: Super Contributor
timestamp: November 07, 2013, 03:17:57 am
content: What kind of terminations or connections will you need to make on the DUT end?

author: nctnico
author_rank: Super Contributor
timestamp: November 09, 2013, 10:30:57 pm
content: Most DUTs will have screw or spring loaded terminals. At least not some high pin count connector.
Favorite d-sub backshell and solder cup connector combo - Page 1
Forum section: electronics / projects

author: ezalys
author_rank: Frequent Contributor
timestamp: August 06, 2020, 10:39:36 pm
content: Hey I have to connect a bunch of thermometers to a high end temperature controller, and the connectors on the temperature controller are all db9s. I'm looking a high end, high quality metallized shell that comes with a nice assortment of grommets and a high quality cable clamp, and a matching solder cup male db9 connectors. Does anyone have a favorite combo on their list of parts?

author: WReed
author_rank: Newbie
timestamp: September 13, 2020, 06:14:38 pm
content: Hi,Probably late to your party, but I've used the DB25 size of these for a couple eight-channel audio snakes:https://www.l-com.com/d-sub-waterproof-d-sub-backshell-kit-db9mI don't know the temps they can handle, but L-Com is good with info like that.Good health, Weogo

author: wizard69
author_rank: Super Contributor
timestamp: September 13, 2020, 07:20:43 pm
content: I've used so many different types over the years that I can't say for sure which was the best. The Amphenol 17E-1724-2 is probably the one I see most often and the one I would order if i wanted a plastic cover. However if given a choice I would go for a diecast back shell like: 17E-1657-09.I tend towards Amphenol but obviously there are a lot of options for vendors. The big advantage in my mind when it comes to the dicast solutions is that the metal parts are highly reusable. The plastic solutions vary a lot, with the snap together or the ones using self taping screws, basically one time solutions. The bolt together plastic units are more robust and reusable but in my imagination the diecast are a step above.As for solder cup connectors simply select a better grade of connector. However in my personal opinion the solder cup DB solutions suck. If you are at all looking at production quantities get a crimp pin system. I find soldering DB style connectors to be tedious, beyond that they seem to be prone to failure from poor soldering. fortunately there are lots of options for crimped style pins for the DB system all the way up to mil spec barreled crimps.By the way there is another problem with solder cupped DB connectors and that is that some manufactures use plastics that melt way to easy. You need to work quickly which sometimes isn't easy when working with multi wire cables. Off the top of my head I'm not sure who is better with this issue.
Favorite resources for simple home network designs? - Page 1
Forum section: electronics / projects

author: cdev
author_rank: Super Contributor
timestamp: February 10, 2018, 03:47:52 pm
content: What are good resources for designing home networks? My home network has grown and its outgrown the methods I have been using to manage it, and its time to make some changes. Eventually i would like to have everything be gigabit-ethernet capable but right now I have a mix of fast-ethernet and gigabit capable devices and switches. I have one old managed switch, which is gigabit capable, but almost a decade old.Edit: I probably have it mostly figured out by this point but in looking for a network planning app I found net2plan which is not for home networks, its for large ones. But fooling around with it is quite interesting. So I am posting the link.----http://www.net2plan.com/
Favourite PCB mount through hole tactile push button switches  - Page 1
Forum section: electronics / projects

author: Jester
author_rank: Frequent Contributor
timestamp: February 25, 2024, 01:18:43 pm
content: I'm going to be making a control panel for CNC control of a milling machine I recently purchased. About ten years back I did this for a small mill (image below). For the old panel I used several different style switches and they all have advantages and disadvantages, all of the original switches have worked perfectly no failures.SMALL ROUNDAdvantages: smaller, easier to keep finger on the button while looking elsewhereDisadvantage: button tip has tendency to rock to the side, so it feels cheapBLUE ROUNDDisadvantage: Somewhat large, tactile pressure excessiveSMALL SQUAREThese are ideal. I would use them everywhere but I prefer to have different styles/shapes to help delineate by function.I'm looking for options, some buttons just feel better than others. This panel is not exposed to fluids so IP protection is not required. Suggestions welcome.

author: tooki
author_rank: Super Contributor
timestamp: February 25, 2024, 05:11:18 pm
content: Do theyhaveto be PCB mounted?I see you’re using a PCB as the front panel, but could you use panel-mount switches mounted into large holes in that PCB instead? Then just wired up from behind?I ask because I actually quite like this style of Chinese panel-mount tactile switches:https://www.aliexpress.com/item/1005005770971655.htmlThat particular vendor even lets you order them with custom legends. They come in many sizes, with or without backlights, in various backlight colors (including RGB), with leads on JST connectors, or solder lugs. Note that the tactile ones are the style called “short stroke”, “ultra short” or “ultra thin”, because otherwise, most buttons that look like these (when mounted) are mechanical buttons or latching switches with long bodies extending inside.Here’s another listing, with more sizes, but fewer colors:https://www.aliexpress.com/item/1005001683893211.htmlThis one has two different heights of keycap:https://www.aliexpress.com/item/4000062661805.html

author: kimballa
author_rank: Contributor
timestamp: February 25, 2024, 05:16:42 pm
content: I use small round Omron BF-1020 or other BF-1/3/5xxx series where I value small size and cost minimization.I'm working on a project now where I need switches mounted on pcb at a right angle to the front panel and just bought a handful of JB15KH-6H. They're very nice looking, 1 cm square cap, feel high quality and have a very sturdy 6 pin THT mounting structure, but they're quite pricey.Looking at your example panel there, you could also peruse digikey's "pushbutton switch" category in addition to "tactile switches" for options. Many low-profile panel mount options in there (including momentary / off-mom function) that might fit the bill for you.
favourite RJ12 tester? - Page 1
Forum section: electronics / projects

author: k8943
author_rank: Regular Contributor
timestamp: January 27, 2020, 07:24:29 am
content: Anyone have a favourite RJ12 cable tester? Ideally that gives a clear audio warning after you've told it what kind of cable you're expecting (in my case 4 wires, maybe that's RJ11). And that indicates which wires are concerned in the issue, to aid figuring out which crimp needs redoing.They tend to look pretty similar with LEDs at each end that flash in sequence. Problem I just had with mine (a cheapo) is that somehow I missed a crossed-wire scenario, which resulted in several blown buck converters on my boards (I thought it was a snubber issue) and a lot of wasted time.

author: Gregg
author_rank: Super Contributor
timestamp: January 27, 2020, 07:19:52 pm
content: My personal favorite RJ11, RJ12 and RJ45 as well as coax tester is the Fluke MS2. I have the kit with the sorting dongles that has paid for itself many times over. The sorting dongles can be a real time saver. This device also shows the cable length and/or the length to a faulthttps://www.testequipmentdepot.com/fluke-networks/copper-certification-and-testing/cable-verification/microscanner2-professional-kit-ms2-kit.htm?gclid=EAIaIQobChMIgYb8qL2k5wIVziCtBh2EYQC9EAAYAyAAEgL4Z_D_BwEI also would suggest the crimp ends that have through holes for the wires like these: I have crimped over a thousand of these (RJ45) and only had one that had a bad connection.\https://www.amazon.com/Connectors-Through-Ethernet-Plated-Network/dp/B07S2QZZZF

author: k8943
author_rank: Regular Contributor
timestamp: January 29, 2020, 06:41:37 am
content: Think I could live with that Fluke setup.Pity that RJ11/12 don't seem to exist in pass-through. That would indeed eliminate a whole bunch of errors.
Faxitron Mammotome X-ray machine Tear down  - Page 1
Forum section: electronics / projects

author: Alphatronique
author_rank: Regular Contributor
timestamp: September 04, 2025, 12:54:09 pm
content: as PCB assembly shop i look for a small low cost ans "safe" X-ray system for a while ,first idea was to use china dental system but that really unsafeso i found many Faxitron Mammotome on ebay that seem to be used for breast cancer but hologic buy faxitron and end of support on some older systemthis make appear on ebay a cheap priceso a buying one a for 350$ USDhere the good and the bad newson the good sidewhole system is under 50lbs so easy to ship via normal wayX-ray tube is really nice micro focus tube (Oxford instruments PN: 93095 ) ->https://img1.17img.cn/17img/files/201907/attachment/9a4d8c2b-d080-4c5c-91c0-dcf6fc3ae567.pdfmatching HV power supply -> Spellman MNX50P75X4196 ->https://www.spellmanhv.com/en/high-voltage-power-supplies/MNXso it really nice source for the priceon the bad sidemost of the system i see for sale come whit no PC so no software and worst it need special custom made frame grabber that use pair of optic cable ,some post here seem to point that even driver for that card is near impossible to findso forgot idea to use it as is ...the sensor itself also seem custom from bioptics ,on it internal is use 3 X RadEye1 cmos sensor ->http://www.rad-icon.de/RadEye1.pdf,some seem to have make it own interface but it complex and i not have the time so for now the sensor plate is a paper weight , some interesting point PCB of the sensor is made for fit many sensor size and all part is populated it may support up to 12 X RadEys1 CCDthe rest of system have noting really special some power supply board and a display/button board that talk to PC vias USB (FTDI uart )later i found that it also have on sale bigger system called "Faxitron Biovision" that come self contained whit the PC and whit 12" x 12" chamber and 10 x 15mm sensor

author: Alphatronique
author_rank: Regular Contributor
timestamp: September 04, 2025, 01:03:29 pm
content: some more photo ,as you see sample chamber is very smalli end up buying a Faxitron Biovision it 1000$ more but come fully functional

author: ahsrabrifat
author_rank: Regular Contributor
timestamp: September 07, 2025, 09:55:49 am
content: If you just want fast & safe PCB X-ray inspection, keep the microfocus source.

author: BennoG
author_rank: Frequent Contributor
timestamp: September 07, 2025, 11:04:49 am
content: Quote from: ahsrabrifat on September 07, 2025, 09:55:49 amYes I am still looking for a nice microfocus tube. (if you are planning to get rid of it I will buy it from you)

author: Alphatronique
author_rank: Regular Contributor
timestamp: September 07, 2025, 11:37:45 am
content: (if you are planning to get rid of it I will buy it from you)if i chose to sell it will let you knot here , for now i wait delivery of the BioVision system
FCC  Part 15  EMC Product Certification questions - Page 1
Forum section: electronics / projects

author: JoeyG
author_rank: Regular Contributor
timestamp: July 18, 2020, 12:54:57 pm
content: **Is this the right forum?**Thanks in advance. I am looking at testing a product that has an mcu + WiFi wireless module and I have a few questions I hope the group and answer.BackgroundThe electronic product will go through FCC certification.It has a 200MHz mcu + WiFI wireless moduleThe WiFi module already has FCC modular certification, the question is about EMC testingEMC FCC Certification Test Method QuestionWhat mode(s) should the WiFi module be in during EMC testing?-WiFi module off-WiFi module on, but is idle mode , not connected to an access point-WiFi module on an connected to an access point-Other
FCC testing: ANSI C63.4 operating conditions question - Page 1
Forum section: electronics / projects

author: nctnico
author_rank: Super Contributor
timestamp: July 14, 2024, 02:23:50 pm
content: I'm having a discussion with an certification lab somewhere in Asia. The device they are testing has a maximum rating for a 'boost mode' which can only last for a couple of minutes. The common operating condition where the device spends days at is at lower load levels. The test lab however insists on testing at the maximum rating which complicates things for testing and isn't a true representation for how the device is actually used. The ANSI C63.4 document says that devices are to be tested at their nominal voltage and typical load conditions. I think the test lab is interpreting the requirements wrong by insisting on testing at the absolute maximum load. Or is there more to it?

author: jwet
author_rank: Frequent Contributor
timestamp: July 14, 2024, 04:35:22 pm
content: Generally you have to test your equipment in its "worst" configuration. There are a few ways to handle this.Delete boost mode. Is it necessary for the product?"Delete" the boost mode for the purposes of the EMI test. In production, you can have some way of enabling boost mode with a note in the manual that the equipment is non compliant in the boost mode.Negotiate to have the test done in normal and boost modes. You'll get a test report that may show "failures" in boost mode. Do as above. Put an asterisk on you EMI compliance.See what it would take to make the equipment compliant in boost mode- is it really hard?Good luck.

author: nctnico
author_rank: Super Contributor
timestamp: July 16, 2024, 03:20:44 pm
content: I solved the problem. I looked up some FCC reports for similar devices and noticed none of the ones I found (randomly) actually specify the load condition. They just state 'load' in the diagram of the test setup. Also the FCC part 15 'general requirements' section states that it is up to the manufacturer to specify the load conditions. So I put my foot down and told the certification lab which load conditions they should test with.It is just dissapointing the test lab couldn't come up with this themselves.
FCI/AMP "Clincher" FFC Connector Help Needed - Page 1
Forum section: electronics / projects

author: jpanhalt
author_rank: Super Contributor
timestamp: October 27, 2016, 04:49:07 pm
content: FCI (aka AMP) produces a connector called "Clincher." It is listed as an IDC type for FFC or maybe even FPC cable. Unfortunately, documentation specific to how to use it seems to be missing -- at least the appropriately named link has been down for awhile. Both DigiKey and tech service chat at FCI link to conventional, not IDC, connectors. A link that presumably describes the Clincher appears to have been down awhile.Here's the link, in case it is a browser issue:http://portal.fciconnect.com/Comergent/fci/documentation/950526-004_clincher.pdfDoes anyone know whether insulation from one side of the FPC cable needs to be removed? My strong suspicion is "no," but I have not been able to find a definitive statement from FCI/AMP to that effect. The product is listed as an IDC connector, and the advertising splash describes the electrical contacts as "air tight," which I interpret as supporting my suspicion that the insulation does not need to be removed.Regards, John
FE-5680A Rubidium oscillator bootloader details - Page 1
Forum section: electronics / projects

author: Leo Bodnar
author_rank: Frequent Contributor
timestamp: January 04, 2020, 06:26:38 pm
content: Does anyone have details of FE-5680A bootloader protocol for the unit with a fixed 10MHz output (later model based on MAXIM DS80C323.)I believe early models using PIC16 are not Flash upgreadable.CheersLeo