hybridfree/eevblog-posts huggingface dataset:
Edit Part Dimensions in EasyEDA - Page 1
Forum section: electronics / projects

author: dellsam34
author_rank: Regular Contributor
timestamp: July 04, 2021, 10:44:55 pm
content: Total noob here, My first schematic on EasyEDA following the project in this link:https://www.eevblog.com/forum/manufacture/from-schematic-to-pcb-282641/msg3583663/#msg3583663One component I cannot find the right dimensions for and I have to manually edit it, I did but when I hit place button nothing happens, Maybe because I was editing the footprint not the symbole, anyway I have no clue how to accomplish this despite searching google and youtube tutorials.The component in red is the one I want to edit the leg spacing from 27mm to 37.5mm, Here is the Mouser component page:https://www.mouser.com/ProductDetail/Panasonic/EZP-Q33355LTA?qs=%2Fha2pyFadui42GvL3EnWSzp04gCN3Eej7mlUjslZhwNz7RZkamh1HLEUIi3uYzbzSee Schematic below:

author: kjr18
author_rank: Regular Contributor
timestamp: July 05, 2021, 08:22:48 am
content: It's not easy to edit footprint directly from your schematic, at least I don't know any method to do it.Anyway, there is another method: first you need to find your part in library, then click on footprint on the right. It should open in another tab, edit what you need, then save it under new name (copy name to clipboard for later).Next, go to main menu, select Tools > Footprint Manager, then select your part on the left, on the right in search window paste your edited footprint name, select it on list below (sometimes you get more than one result if your new footprint name is not unique enough) then click Update button below.Now your part in schematic should have new footprint. All that's left is to save schematic and update pcb.

author: dellsam34
author_rank: Regular Contributor
timestamp: July 05, 2021, 04:05:38 pm
content: Thanks, I saved the edited footprint to my favorites and from the schematic menu on the right I double clicked footprint a window popped up and selected favorites and found it there.
EE Iceberg Chart - Page 1
Forum section: electronics / projects

author: sahko123
author_rank: Frequent Contributor
timestamp: March 15, 2022, 02:50:22 am
content: For shits and grins I've decided to make a tier list for various EE components/topics.Comment any changes you would make and if you want make your own!

author: T3sl4co1l
author_rank: Super Contributor
timestamp: March 15, 2022, 04:43:27 am
content: Looks about rightEM Fields, EMC, related topics, something like that, are missing in the level below Antennas.Tim

author: Berni
author_rank: Super Contributor
timestamp: March 15, 2022, 06:41:39 am
content: Yeah definitely needs some Microwave RF circuits down towards the bottom 3 levels. That stuff is black magic.
EE Schematic Help for an interactive sculpture - Page 1
Forum section: electronics / projects

author: jbf
author_rank: Contributor
timestamp: May 25, 2023, 07:33:10 am
content: Hey EEVBlog friends,I'm working on a circuit design for a sculpture that uses a fan to make it appear that the sculpture is breathing and wanted to get some circuit design advice. My plan is to use an MCU to control and sync a fan with audio playback and I have a basic design I think could work.I wanted to get your expert opinions on my circuit design and find out ways to make it sufficient (and become a better circuit designer in general).The fan control circuit is what I'm most looking for design advice on.Details:- Teensy 4.0 Digital IO pins control logic.- 12V DC Fan with 220mA max current draw (this is hidden inside of the larger sculpture)- 12V DC Supply for Fan + 20W Audio Amplifier Board- 12V to 5V Regulator for driving Teensy 4.0 (Onboard regulator will lower this to 3v3)- Mosfet is anRFD14N05L(I had these in my studio lab already)- Reverse Diode (EMF protection) using 1N4001- 10K pulldown resistorDuty CycleFor now switching will be on/off. Motor on for anywhere from 30s - 3 minutes, and then off 10-20 seconds, and then repeat.This said,I may want to use PWM to slow the fan speed as it approaches the "off" moment of the audio track.This duty cycle should be repeatable for 8hrs / 5-7 days a week for a couple weeks at a time at minimum.Below I've attached a schematic.Anyone have any advice? Should I be using an opto-coupler like a PC817 (i have many of these in my studio workshop) to drive the mosfet or would this be good enough?

author: Jon_S
author_rank: Contributor
timestamp: May 25, 2023, 12:18:33 pm
content: Right, now that I have looked at the correct datasheet for that FET it seems fine at 3V3 Vgs. Sorry about that, typo'd the P/N while googling for the datasheet at first.Can't see any issues here. I have never used a Teensy, but direct drive seems like it would have no issues on this circuit. The I/O pins are specified as capable of 20mA, so it should drive that amount of gate capacitance more than fast enough for any reasonable PWM you would want to do on a small load like that.

author: jbf
author_rank: Contributor
timestamp: May 25, 2023, 07:52:39 pm
content: Quote from: Jon_S on May 25, 2023, 12:18:33 pmThanks so much Jon_S. I'm still a novice with circuit designs and datasheets often trip me up (aka not knowing what a specific parameter is or how it interacts with a different variable etc).
EEPROM for Automotive  - Page 1
Forum section: electronics / projects

author: hdautoclinic
author_rank: Newbie
timestamp: August 02, 2015, 01:36:59 am
content: Does anyone have information on what data is stored at particular EEPROM address? For example, RPM data info may be found in blocks 10-11. I appreciate any help or reference I can get.Thanks a bunch!Howard

author: kizzap
author_rank: Unknown
timestamp: August 02, 2015, 05:31:21 am
content: It is 100% application specific. Same chip can be used in many ways.
EEPROM page questions... - Page 1
Forum section: electronics / projects

author: alank2
author_rank: Super Contributor
timestamp: May 13, 2016, 10:42:49 pm
content: So an i2c eeprom like this:http://www2.st.com/content/ccc/resource/technical/document/datasheet/e0/4c/87/45/e8/bd/4f/11/CD00251873.pdf/files/CD00251873.pdf/jcr:content/translations/en.CD00251873.pdfSays it has a page size of 128 bytes which is great. Honestly I was much more impressed with these things when I found you could write an entire page at one time.The manual says in the ECC section works on groups of 4 bytes and that if you change 1, it will rewrite the other 3 whether they have changed or not.My first question is - ST lists their write endurance at 4M when almost everyone else says 1M. Is this because they are looking at this 4 byte group/ECC differently than other manufacturers. Is their "4M" the same as others 1M ?Second question is - since this 4 bytes is obviously smaller than the page size, this would mean that an entire page can be written in a single write cycle, but does not have to be. Given that, do these chips have any sort of logic to prevent writing the same bytes? In other words, if you write the same 4 byte values for a group, will they be rewritten or does the device know they did not change and won't have to be rewritten?

author: uncle_bob
author_rank: Unknown
timestamp: May 14, 2016, 04:08:50 am
content: HiAny time you look at endurance on memory, it's very important to read *all* the fine print. Is it at 25C or at 70C? Is it 99% sure or 99.99% or 60% sure? There are enough variables that a good marketing guy can get creative.Error correction *should* improve the memory endurance. If it does not - why do itDo the chips recognize a re-write of the same data? Probably not. You tell it to write, it erases whatever it needs to and then writes it. It sounds from your description like the minimum erase group is the range of the ECC bits. That's fine if you always write 4 bytes. Maybe not so fine if you tend to write a byte here and a byte there....Bob

author: alank2
author_rank: Super Contributor
timestamp: May 14, 2016, 12:47:16 pm
content: Thanks Bob - I did some testing last night and it does indeed rewrite the same values if you ask it to in a write cycle. I had a technique I was using for wear leveling, but looking at the way I did it the first time, I think it is time for some improvements.
EEPROM UPA CABLE for "in circuit" data update - Page 1
Forum section: electronics / projects

author: Franco
author_rank: Newbie
timestamp: March 07, 2021, 11:03:52 am
content: Hi Guys,Someone else here has bought or tested this EEPROM cables from this websitehttps://www.3ello.com??I am going to buy to repair corrupted data from IC memories, the good point of these cables is that is build with Guide Cap for easily alignment and don't need to remove IC from pcb board.If someone here has tested and can give some comments for my decision to buy or not would be helpfulBcz the items looks very good quality and make me very interested to order one set with 3 version Msop/ Tssop/ Soic.https://www.3ello.com

author: Franco
author_rank: Newbie
timestamp: March 15, 2021, 01:27:22 pm
content: Hi Guys today I received my Set of Eeprom Upa pogoping cables, these are very good quality, its was worth to have, easily IC feet connection by Guide cap.Here some pics for references, I hope this can help someone else.

author: Morrisohbig
author_rank: Newbie
timestamp: July 19, 2022, 06:08:12 pm
content: Am also interested. First an interested with the cables to use with my TL866. How about their stand alone programmer. How did ot work?
EEV Blog Speak n'Say (Design Files in Links) - Page 1
Forum section: electronics / projects

author: Grippy
author_rank: Newbie
timestamp: January 19, 2019, 08:28:07 pm
content: Hi All,Long time viewer of the show and I recently ran into the Ben Heck episode in which he built a Dave Jones Speak n'Say. It looks like a fun little project to tackle, and since Ben never published the design files or sizing for the labels I decided to build my own with a few extra touches like random sounds for every vocalization.Here's the result:All the files needed for it and a write-up of how I built it can be found in the video description (on my blog and GitHub respectively).It was a really fun afternoon project and definitely worth building if you ever find yourself bored. I already had all the electronics needed to put inside so I'm only out $9 for the Speak n'Say from Target.I hope Dave sees it and has a chuckleLet me know what you think!

author: cdev
author_rank: Super Contributor
timestamp: January 20, 2019, 01:27:34 am
content: Thats just great!
EEVblog 1453 Elgato Key Light Power Transistor - Page 1
Forum section: electronics / projects

author: petersanch
author_rank: Regular Contributor
timestamp: March 04, 2022, 11:34:51 am
content: In Dave's Elgato Key Light teardownhttps://youtu.be/kcWwAweWjQg?t=464he says at 7:44 'They've done their calculations and they're dropping all the power in the power resistor instead of the power transistor.'Can some one explain what he means? Does it mean the power transistors Ron is much lower than the power resistors?Cheers

author: Kleinstein
author_rank: Super Contributor
timestamp: March 04, 2022, 01:13:07 pm
content: The LEDs need some way to limit / set the current. This could be done with series resistors (relatively cheap) or with a much smaller resistor and a transistor for a more stable current and maybe less votlage lost. With a reguted SMP for the input the resistor solution is not that bad.
EEVblog #38 - LCR Meters, Transmission Lines, and Moving goal posts - Page 1
Forum section: electronics / projects

author: chrisjn52
author_rank: Newbie
timestamp: November 12, 2017, 10:43:07 am
content: Ref: LCR Meter equationsHi,I'm having problems using the equations shown in video #38.I would appreciate more information or a link to a description of this method in order to check the the derivation of the formulas.I'm checking the results in Ltspice of a known network measurement shown here.......https://www.testequity.com/documents/pdf/applications/oscilloscope-measure-impedence-capacitance-guide.pdf
EEVBLOG #569 switchs - Page 1
Forum section: electronics / projects

author: mm50
author_rank: Newbie
timestamp: March 07, 2015, 03:10:31 pm
content: Hello, i am working on something and was looking for a push button and I found them except I did not ( I don’t know the part number). In EEVBLOG #569 at 7:18 there is the "HPA-4387 AUTO CONTROL" what are the push buttons on it, it dos not have to be the specific button just the same style.thanks,Michael Montreuil

author: Asim
author_rank: Regular Contributor
timestamp: March 07, 2015, 03:24:40 pm
content: I think what you mean is a rotary switch.

author: rdl
author_rank: Super Contributor
timestamp: March 07, 2015, 04:00:35 pm
content: Those look like the kind of pushbutton that has a removable cap. You can unsnap the cap and insert a custom label. They can be made with illumination. NKK is one company that makes this style of pushbutton. Here is a data sheet that has a few that are very similar to the ones in that video. You may have to do a lot of searching to find exactly what you want. You generally buy the cap and body as two separate parts, and this type of switch tends to be pretty expensive.http://www.mouser.com/ds/2/295/ybnonilluminated-32298.pdfalso:http://www.nkkswitches.com/series.aspx?stid=3&id=5007

author: mm50
author_rank: Newbie
timestamp: March 07, 2015, 04:05:10 pm
content: HEY thanks these are close
eevblog CC load style circuit; Hot mosfet - Page 1
Forum section: electronics / projects

author: Rinzevdk
author_rank: Newbie
timestamp: June 12, 2013, 03:12:17 pm
content: HeyI have designed the following circuit with allot of inspiration from Dave`s CC load. the circuit displayed below has on the top right connection to a DC motor. The rotary switch lets you choose the set voltage that controls the current flowing through the motor and R1. The problem is as follows: i made a few of these to go in a device with the mosfet DMS3014SSS-13 now i try different wosfets like IRF7807 and the mosfet gets hot. and even dies. This did not ocur with the old mosfet. whats the problem?the current flowing is 0.1 0.2 0.3 0.4 and 0.5 Amps. witch is peanuts for the mosfet. i have no idea whats going on. any help or tips? thanks in advance !

author: muvideo
author_rank: Frequent Contributor
timestamp: June 12, 2013, 06:04:38 pm
content: That is a linear constant current sink, it's expected to dissipatein heat a good amount of power, in your schematic V(M-)*Iwill be dissipated in heat.The mosfets you are using are small smd parts, mainly forswitching use, better use bigger devices in TO220 package.

author: P_Doped
author_rank: Contributor
timestamp: June 12, 2013, 06:30:20 pm
content: These MOSFETs are designed to be operated typically as switches. That's where the dc current rating comes from for these parts. As soon as you operate them in the linear mode (not as a switch, but a normal transistor current source), it's the power dissipation that limits the current capability for your application. Even SMD parts may have an exposed pad underneath the part that gets soldered down to assist with moving heat away from the part. Look at the theta-jc (junction to case thermal resistance) or theta-ja (junction to ambient) to help you decide which part will work for your application.

author: Rinzevdk
author_rank: Newbie
timestamp: June 13, 2013, 07:37:12 am
content: Thanks for the reply's i checked the sheets for the Pd and the heat-resistances. i still wonder why the old mosfet worked and this one doesn't. Because the old mosfet has worse heat-resistance then the new one. May be just luck.There is little room for a heatsink in the device. any chance for a switching cc load ? or a other type of circuit? thanks again !

author: muvideo
author_rank: Frequent Contributor
timestamp: June 13, 2013, 08:33:25 am
content: Quote from: Rinzevdk on June 13, 2013, 07:37:12 amSo, given the data you are working with less than 2V Vds?As for switching designs, if you are driving a motor it's easy,you can use it's internal inductance as a current flywheel,just provide the path for current circulation into the motorwhen the switch is open (for example a schottky diode fromthe drain to the positive rail). I dont have a schematic athand, but there are ready solution used to drive coilsand stepper motors, see for example ST or Allegro parts.
EEVblog Episode 555 - Page 1
Forum section: electronics / projects

author: BentWire
author_rank: Newbie
timestamp: November 20, 2013, 05:21:43 am
content: EEVblog episode 555 is fast approaching. What amazing topic does Dave have planned for this most notable number? Post your predictions here!

author: MrAureliusR
author_rank: Unknown
timestamp: November 20, 2013, 05:41:07 am
content: lol clearly the 555 timer special! I've got almost 50 of them lying around -- can you show us how to build something with 55 555 timers? Or maybe more about the internals, and the fundamentals behind how they work?I really hope he does it on the topic of the 555 -- I mean, how could you not? It's too perfect!

author: BravoV
author_rank: Super Contributor
timestamp: November 20, 2013, 05:50:59 am
content: https://www.eevblog.com/forum/chat/555th-video/
EF2105 Device in ELV Distortion Factor Meter? - Page 1
Forum section: electronics / projects

author: Chris56000
author_rank: Frequent Contributor
timestamp: October 10, 2023, 03:29:17 pm
content: Hi!Can anyone suggest what the EF2105 device IC4 is on the oscillator board circuit of this ELV Distortion Factor meter is please?The German description of this part of the circuit comes out (roughly!) as :–"Stabilization of the oscillator is achieved by the fact that the output amplitude, which is buffered via OP 6. queried and rectified with the help of OP's 3 and 4. The subsequent 0P2 with downstream buffer amplifier OP 1 is used to compare the amplitude with a reference value, which can be set with R13. At the same time, integration takes place. so that the output of OP 1 controls the input circuit of the EF 2105 in such a way that the amplitude stabilization of the output voltage occurs."The circuit suggests its some sort of voltage–controlled resistance, e.g. mosfet perhaps?All I can find when I look up that number is capacitors or stupid Volvo car nonsense!Chris Williams

author: Kim Christensen
author_rank: Super Contributor
timestamp: October 10, 2023, 03:52:28 pm
content: Quote from: Chris56000 on October 10, 2023, 03:29:17 pmThat's what it is. While a FET can do a similar thing, this looks like it's an IC that's been optimized for linearity (voltage vs resistance). So just throwing any old FET in there probably isn't going to work properly.

author: TimFox
author_rank: Super Contributor
timestamp: October 10, 2023, 04:34:32 pm
content: It's an odd pin-out for a FET device: could it be possibly an opto-coupler, such as an LED illuminating a CdS photoconductor?

author: Chris56000
author_rank: Frequent Contributor
timestamp: October 10, 2023, 04:41:14 pm
content: I've just had a thought – is it an LED/LDR combination?The photograph of the board shows a round can device about 20 mm wide and about 20-30 mm high – is there a ready–made LED/LDR assembly available?Has anybody got one of these meters they can do a couple of quick tests on the EF2105 for me please?Chris Williams

author: klootnz
author_rank: Newbie
timestamp: October 11, 2023, 09:11:22 pm
content: 11:45 here:https://www.youtube.com/watch?app=desktop&v=ikW0_0MY-M8
Effect of Clock Jitter on ADCs' SNR - Page 1
Forum section: electronics / projects

author: palpurul
author_rank: Regular Contributor
timestamp: February 20, 2019, 11:57:35 am
content: Hello,I am researching high-speed/high-resolution ADCs and I learned that ADCs require low jitter clocks to preserve SNR. SNR degredation is specified by the famous formula which is given belowSNRJITTER = –20log ((2π) • FIN • TJITTER)Fin: input signal frequencyTjitter: Clock jitter + apeture jitter (or sqrt(Clock_jitter^2+aperture_jitter^2)I assumed clock jitter in the formula is RMS jitter not peak-to-peak (Period jitter). Is my assumption correct?Thanks!

author: Doctorandus_P
author_rank: Super Contributor
timestamp: February 20, 2019, 09:58:58 pm
content: Just go back to the roots.Imagine an ADC with a 0DBFS sine wave at it's input.Zoom in at the zero crossing of the Sine.If a sample is too early, or too late, you will sample a too low or too high voltage.If you do this on a piece of paper, you instantly see the relation between time jitter and measured signal noise.I do not care if you want to measure those errors in peaks, RMS, or potatoes.You should be able to do that yoursef if you know what your units mean.

author: ogden
author_rank: Super Contributor
timestamp: February 20, 2019, 10:21:21 pm
content: There are some useful appnotes around from AD, LT and Maxim. Just random internet search hits, yet giving answer to your question:https://www.analog.com/media/en/technical-documentation/application-notes/AN-756.pdfhttps://www.analog.com/media/en/training-seminars/tutorials/mt-007.pdf

author: asgard
author_rank: Regular Contributor
timestamp: February 21, 2019, 02:28:18 am
content: From an app note from Analog Devices:The relationship between SNR and jitter is given by this equation:<fig1>Maximum SNR vs Clock JitterWhere fin is the frequency of the input signal, and tj is the jitter of the clock. The equation shows that for a high frequency input signal and a fixed amount of jitter the maximum SNR will decrease. This is because a faster slewing signal will have more of a voltage error with a given amount of jitter:<fig2>For input signals that have relatively low frequency content, under 1MHz lets say, the clock jitter becomes less critical, but when the frequency of the input signal is several hundred megahertz the jitter on the clock will be the dominate source of error, and will be the limiting factor for SNR.Here is an easy chart that shows how SNR degrades with input frequency and jitter from the clock:<fig3>
Effect of Coax Test Connector on Signal Integrity - Page 1
Forum section: electronics / projects

author: yrrapt
author_rank: Contributor
timestamp: February 07, 2014, 02:57:43 pm
content: Hi,I'm making up a PCB for a software defined radio and I am wondering about the ramifications of placing a coax connector between the LNA output and mixer input. I want to be able test the LNA/mixer in isolation in circuit by lifting coupling capacitors/0R resistors to ensure they match the measurements I made before on isolated PCBs.Assuming that I place the footprint for an SMA connector with the signal pin in line with the LNA and mixer to trace to avoid any extra trace length or stubs, will the presence of the footprint have any negative effects on the signal integrity? And what difference would there be between the effect of populating and not populating the connector?If it's useful: I only really care about 1.575GHz (GPS), the LNA is 50 ohm output and the mixer IC input is 75 ohm so matching is used and the PCB will be standard FR4.Thanks in advance for any help you can provide,Tom

author: ConKbot
author_rank: Super Contributor
timestamp: February 07, 2014, 05:51:48 pm
content: Your wavelength is ~9.5 cm in FR4(longer with a coplanar waveguide on the surface), so if your stubs are shorter than 5mm or so you shouldnt be too badly affected. However the thoughhole/via can start making stuff a bit funky. I'd put a footprint for a SMT jack (http://www.mouser.com/ProductDetail/Emerson-Connectivity-Solutions/142-0711-201/?qs=iKljIZI%252bxs48GXd9jxbwZA%3D%3D&gclid=COC3t8_HurwCFdHm7AodlyQAAQif you can fit your coplanar waveguide between the 0.125" spacing of the feet. And put your 0R/coupling cap as close as possible to the jack.Oh and I'd also pick up at least a short SMA-SMA cable that is really flexible, rather than a standard cable so you are less likely to accidentally break the connector off
Effect of diode capacitance on high frequency signal? - Page 1
Forum section: electronics / projects

author: TERRA Operative
author_rank: Super Contributor
timestamp: October 09, 2023, 08:35:12 am
content: I'm currently designing my own version of a 3GHz input option for my HP 53132A counter and am substituting some protection diodes as the originals are obsolete.I am hoping someone can give me some info on how diode capacitance will affect the circuit.The original diodes (HSMS-8202) have a max capacitance of 0.26pF and my replacement (RB876WTL) has a typical capacitance of 0.53pF with a max of 0.8pFIt seems the higher reverse breakdown voltage rating, the higher the capacitance. So I would like to use a higher voltage rated part but no so high that the capacitance becomes a problem. (The circuit should ideally go a bit higher than 3GHz in practice)Can anyone educate me on this?Thanks!

author: PCB.Wiz
author_rank: Super Contributor
timestamp: October 09, 2023, 09:04:00 am
content: Can you not find protection diodes for HS-USB etc that have << cap ?Eg 0.15pF or even 0.1pF looks better ?

author: moffy
author_rank: Super Contributor
timestamp: October 09, 2023, 09:22:55 am
content: The BAT15-099 might suit a bit better:https://www.infineon.com/dgdl/Infineon-BAT15-099-DS-v01_00-EN.pdf?fileId=5546d46265f064ff01663896294d4e89as it is a pair of diodes in the same package like the RB876, but lower capacitance ,and will match somewhat so that +ve/-ve is equally distorted when clipping. Search for 'RF Schottky mixer diodes' and you should get a range to choose from.

author: TERRA Operative
author_rank: Super Contributor
timestamp: October 09, 2023, 11:12:15 am
content: Yes, I know what I should look for, but I need to understand why I need lower capacitance and how to calculate or 'rule of thumb' the upper limit of the capacitance.Giving me part numbers, while appreciated, doesn't tell mewhythose part numbers are better.

author: BrokenYugo
author_rank: Super Contributor
timestamp: October 09, 2023, 01:38:03 pm
content: Quote from: TERRA Operative on October 09, 2023, 11:12:15 amI'm no microwave wizard, but isn't this just a capacitive reactance problem? You know, Xc=1/(2πfC) e.g. at 3 GHz 1 pf is about 53 ohms, so you can see how higher capacitance diodes form more of a parasitic attenuator that will drag a weak signal down. How much loss you're willing to put up with is something you have to decide, to beat HP, use a better diode.

author: Marco
author_rank: Super Contributor
timestamp: October 09, 2023, 03:44:29 pm
content: You could do the math, or you could just throw it in a sim :p With 3.2pF you're only down about 5 dB at 3 GHz, the amplification can probably take care of it.PS. oops, I didn't notice the diode pairs were all connected to ground.
effect of low frequency input for VFD - Page 1
Forum section: electronics / projects

author: hussamaldean
author_rank: Unknown
timestamp: January 17, 2019, 10:51:56 am
content: Hi all,I don't know if this is the right section for this post, if it is not then feel free to move it to the correct sectionlet say a vfd is used with lower frequency than 50HZ, say 30Hz. Will the device suffer issues with such low frequency or not ?waiting for your answer

author: Ian.M
author_rank: Super Contributor
timestamp: January 17, 2019, 11:21:08 am
content: Yes its likely to have issues, as it wont have enough reservoir capacitance on the DC bus to maintain its full load output between peaks of the rectified supply.Assuming three phase input, its also likely that it will sense a problem with the input power and shut down at some frequency below its nominal operating range but above your supply frequency. Single phase input VFDs are less likely to have power quality sensing that will trip on low supply frequency.If it doesn't shut down, it *may* be possible to run it at a proportionally derated output current without ill effects.

author: Jeroen3
author_rank: Super Contributor
timestamp: January 17, 2019, 11:45:46 am
content: This is a bad idea. See if you can supply DC directly yourself.Or explicitly ask the manufacturer for derating or operation with lower line frequencies.Theoretically the VFD should be capable of working with lower frequencies.
effect on dissipation with potting compound - Page 1
Forum section: electronics / projects

author: Simon
author_rank: Unknown
timestamp: July 11, 2014, 08:51:03 am
content: If I'm putting a part into potting compound that conducts heat 10x better than Air would it be fair to multiply the amount of W the package can dissipate in free air by 10x, naturally there is more than 10x the surface area of potting compound than there is package surface area.

author: AndyC_772
author_rank: Super Contributor
timestamp: July 11, 2014, 08:55:16 am
content: You need to know the thermal conductivity from the die to the package, as well as from the package to ambient.In some devices, particularly smaller ones, the die already runs considerably hotter than the surface temperature of the device. Improving the thermal conductivity from the device package to the environment won't, therefore, have a major effect on the die temperature.

author: Simon
author_rank: Unknown
timestamp: July 11, 2014, 09:04:38 am
content: Right good point, so reinforces my solution of using SMPS rather than a linear reg that can't handle the power

author: tszaboo
author_rank: Super Contributor
timestamp: July 11, 2014, 11:20:45 am
content: Most of the dissipation of the devices (well SMD at least) goes into the board. Also with air, the air moves so conductivity doesnt really matter that much, while the airflow does. I wouldn't be surprised, if you are not using special potting for thermal management, you actually have to derate the component.Think about the whales vs human. Whales have bigger body and more surface, but if you drop both of them into ice cold weter, the human will die, because the core temperature will quickly drop.

author: Simon
author_rank: Unknown
timestamp: July 11, 2014, 11:38:01 am
content: the air wont be moving in any case except by natural convection
Effective dimensions of binocular ferrite core - Page 1
Forum section: electronics / projects

author: Telegraph
author_rank: Newbie
timestamp: January 04, 2021, 07:26:15 pm
content: I was trying to do calculations on a ferrite binocular core. I found formulas to calculate the permeability that require the effective area and magnetic path length. For a regular toroid, or bead, that appears to be straight forward. What about a binocular (mulit-aperture core)? I found documentation for more complex arrangements, such as, E-cores but nothing on the binocular format.

author: richard.cs
author_rank: Super Contributor
timestamp: January 04, 2021, 11:01:49 pm
content: Treat is as two independent tube cores, each like a long bead.

author: igor78
author_rank: Contributor
timestamp: March 28, 2023, 06:23:31 am
content: This topic comes first in websearch. For future readers:Page 2 herehttps://www.tdk-electronics.tdk.com/inf/80/db/fer/double_aperture_cores.pdfNotice the dimension units there mm^-1Also seehttps://owenduffy.net/blog/?p=14712"Geometry factors for some common Fair-rite binocular ferrite cores"CoreBN designationΣA/l (m)2843000202BNxx-2020.002882843000302BNxx-3020.002112843001502BNxx-15020.001392843002402BNxx-24020.0015428430104020.00308

author: jonpaul
author_rank: Super Contributor
timestamp: March 30, 2023, 01:48:13 pm
content: for,a shield EMI bead, see mfg specs,for use,as balun, the exact spec is seldom importantWe just wind and test on a high frequency RLC or impedance analyzerj

author: jonpaul
author_rank: Super Contributor
timestamp: March 30, 2023, 01:50:42 pm
content: beside TDK try old Fair-Rite, EPCOS, Philips data.j
Effective routine to determine speed using a reed switch - Page 1
Forum section: electronics / projects

author: XaviPacheco
author_rank: Regular Contributor
timestamp: August 23, 2018, 02:06:06 pm
content: I have an old treadmill which has a reed switch by default to "measure the speed". It's like shown in the attachment.As you know, reed switches have very poor resolution, i.e, a pulse per revolution. And, at low speeds, this is terrible. But I'm curious about how I can create a code with STM32 to effectively measure the speed without a time-consuming routine. I know there are better sensors with better resolution, but this time I would like to take advantage of the structure of the machine, instead of adding another sensor.Interrupts services, or what?I would appreciate any ideas.

author: MasterT
author_rank: Frequent Contributor
timestamp: August 23, 2018, 05:10:47 pm
content: Quote from: XaviPacheco on August 23, 2018, 02:06:06 pmTo measure high frequencies count unknown frequency pulses at the input during known gate time (1 sec).To measure low frequencies count known frequency pulses (from internal timer perhaps) during unknown gate - reed switch.Micro-controllers have special feature, called ICP - input capture. Dig your stm32 data sheet, than examples code from the google how to use an ICP.
Effectiveness of partial Faraday Cage? - Page 1
Forum section: electronics / projects

author: @rt
author_rank: Super Contributor
timestamp: October 07, 2016, 09:14:02 am
content: Hi GuysI was wondering what if any effectiveness is provided by a partial Faraday cage shielding an analogue circuit from a digital circuit on the same PCB.I imagine if you had an open side facing away from the radiator, that should be somewhat effective as an antenna ground plane or even a antenna or satellite dish would be, or am I way off here?Cheers, Art.

author: bson
author_rank: Unknown
timestamp: October 09, 2016, 05:57:21 am
content: If it's open on one side it's not a Faraday cage and it won't keep out signals along an aperture formed by the opening. However, if you ground it it will still be effective as an EMI shield. (A Faraday cage doesn't need to be grounded.)

author: Gyro
author_rank: Super Contributor
timestamp: October 09, 2016, 08:58:57 am
content: Hi Art. Strictly speaking, you don't have a Faraday cage in the first place. A Faraday cage is, by definition, an uninterrupted conductive enclosure. As soon as you have signals going into and out of it, what you have is simply a screen, not a Faraday cage.The lowest frequency 'airborne' (radiated) signal that can get in and out of a screened enclosure are defined by its wavelength in comparison with the longest dimension of any aperture in the screen. Conducted signals into the enclosure are dependent on how well they are filtered and decoupled to the screen.The basic advice is to keep the apperture as small as possible. If possible make multiple smaller apertures rather than one big one (tabs down to the ground plane). filter and decouple signals going in and out of the screen as well as possible.

author: ChristofferB
author_rank: Frequent Contributor
timestamp: October 09, 2016, 10:42:33 am
content: The tinfoil-hat dilemma. You can probably get some benefits from partial shielding- i believe it's seen both in rf cans, and especially copper-clad Manhattan construction, to use partial "walls" of either sheet metal or copper clad board, to separate filters, filter stages etc. I don't know HOW effective it is, though.
effects of AC ripple in DC power supply? - Page 1
Forum section: electronics / projects

author: jonny_w
author_rank: Contributor
timestamp: August 05, 2014, 05:30:05 am
content: I built this power supply for my synthesizer project:On my scope, I'm reading 400mV AC ripple on the +12V output (11.83V actual), and 1.6V ripple on the -12V (-12.15V actual) output.NOTE: I blew up C4, C5, C9, and C10 the first time I powered it up (wrong polarity, DOH!). I replaced them, but maybe the regulators are damaged?I'm thinking this may be leading to some of the unusual problems I've been having with my op-amps, as they're all powered by this supply. Should I replace the regulators AND the electrolytics? What are the effects of this much ripple?

author: mij59
author_rank: Frequent Contributor
timestamp: August 05, 2014, 06:08:09 am
content: Hi,Very strange design.Remove the voltage regulators and measure the voltage across C1 and C6.The voltage of C1 should be about +18V, C6 should be about -18V.If so install new voltage regulators, and check again.

author: jonny_w
author_rank: Contributor
timestamp: August 05, 2014, 06:09:59 am
content: Quote from: gazelle on August 05, 2014, 05:49:31 amI'll do that, for sure. One thing I did (before I finally go to bed) was check the forward bias resistance of one of the diodes. It registered 0.7 Mega-ohm, with the multimeter positive lead on the anode & negative lead on the cathode, resistance test. This seems a little...odd. When I flipped the leads, it read O/L, which I expected.Thanks for the link, btw!

author: jonny_w
author_rank: Contributor
timestamp: August 05, 2014, 06:11:12 am
content: Quote from: mij59 on August 05, 2014, 06:08:09 amHow is it strange? I'd like to learn as much as I can about this sort of thingI'll check the voltages tomorrow. Thanks for the reply!
Effects of increasing copper thickness for outer layers - Page 1
Forum section: electronics / projects

author: Sai teja
author_rank: Regular Contributor
timestamp: January 29, 2018, 11:21:24 am
content: Hello ,Currently I am working on project which requires editing the existing files. Existing design includes Bluetooth SOC with antenna matching circuitry. Existing files fab docs suggests to follow 1/4 oz for top and bottom layers. But my manufacturer can provide minimum of 1 Oz copper thickness.I would like to know the effects of increasing copper thickness.Please help me in this regard.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: January 29, 2018, 08:04:12 pm
content: Beats the hell out of me, who engineered the layout, ask them?I would be more worried that, if they can't hold spec on thickness, they certainly won't hold spec on clearance and trace width, or laminate thickness, or dielectric constant.Tim
Efficiency of DCDC converters  - Page 1
Forum section: electronics / projects

author: joniengr081
author_rank: Regular Contributor
timestamp: June 21, 2024, 06:12:28 am
content: Hi, I am wondering how the efficiency of DCDC converters is defined. I have checked the specs of some commercial DCDC converters, they have efficiency between 80% to 90%. What does it means ? If this power efficiency then can we say that the output power is 80% or 90 % of the input power ? the remaining are thermal and switching losses ?There are two main types of DCDC converters, the Buck converters and the Boost converters. The definition of efficiency is same for both type of DCDC converters ?

author: moffy
author_rank: Super Contributor
timestamp: June 21, 2024, 06:44:37 am
content: Efficiency is the ratio of (output power)/(input power) as a percentage. It will vary with load and input and output voltages if they are variable and the measure is the same for BUCK or BOOST.

author: joniengr081
author_rank: Regular Contributor
timestamp: June 21, 2024, 11:22:00 am
content: I understand. Thanks for reply.Does it also means that the output power (Vout x Iout) is always less then the input power (Vin x Iin) ? And this is true for both Buck and Boost converter ?

author: moffy
author_rank: Super Contributor
timestamp: June 21, 2024, 11:27:25 am
content: Quote from: joniengr081 on June 21, 2024, 11:22:00 amThat is a fundamental of physics, there are always losses in any DC/DC converter.

author: Psi
author_rank: Super Contributor
timestamp: June 21, 2024, 11:44:29 am
content: Quote from: joniengr081 on June 21, 2024, 11:22:00 amYes, output voltage or current can be higher than the input, but the power must always be lower than input.Efficiency gets super important when you are working with crazy amounts of power.eg, 50+kW electric vehicle charging. Even if you have a 95% efficient DCDC, if you're pushing 50kW through it you need to manage and dissipate 2.6kW of raw heat
Efficient and low EMI TEC-Driver suggestion? - Page 1
Forum section: electronics / projects

author: Echo88
author_rank: Frequent Contributor
timestamp: July 24, 2021, 01:16:53 pm
content: Thinking about efficient TEC drivers (max 20W electrical input range or so) that produce low EMI, i came across this LT1534-application-suggestion:https://www.analog.com/media/en/technical-documentation/data-sheets/1534fa.pdfPage 14In this case its only able to cool or heat and not both.Any ideas wether such a simple IC which can do buck or boost can be made to manage both heating and cooling with a smooth transition between both modes, avoiding sudden jumps?One could of course use the LTC1923, which is made for this task, slew rate and does it all, but is quite costly.Competitors are ADN8834 (no mention of EMI reduction features) and MAX1968 which id like to avoid when thinking about long term availability.Never really found SMPS-ICs (Buck, Boost, Push Pull for example) that claim slew rate limiting apart from the ones Linear (LT1533,1534,1738 for example). Are there any from other vendors or is it a patented technique?Any other suggested methods, suitable ICs or even OSHW-designs that would do it?Thanks.

author: MarkL
author_rank: Unknown
timestamp: July 24, 2021, 03:18:33 pm
content: Take a look at TI's line of PWM TEC drivers:DRV591DRV592DRV593DRV594DRV595They are all bridges with built-in, protected drivers, and they can heat or cool with no transition discontinuities (the 593/594 is a half-bridge with automatic crossover control). The parts cover a couple of different output voltages and current, and digital (PWM) or analog control input.They're efficient, but EMI mitigation is something you're going to have to design in. EMI design is discussed in the datasheets.
Efficient DC-DC Boost converter with low voltage cut-off - Page 1
Forum section: electronics / projects

author: peter.rao76
author_rank: Newbie
timestamp: February 28, 2022, 02:14:23 am
content: Hi All,I am looking to use a 12V SLA in place of multiple AA batteries (6V total) for a device that consumes them quickly and so am in need of an efficient DC-DC step up converter with low voltage cut-off.I have looked at several stand alone low voltage cut off devices though they generally have a reasonably high standby drain (esp when added together with the DC-DC converter).Whilst looking around I have come across the Pololu S9V11MACMA - 2.5-9V Fine-Adjust Step-Up/Step-Down Voltage Regulator w/ Adjustable Low-Voltage Cutoff (https://www.pololu.com/product/2868) which appears to fit the bill though I was wondering what others have used and whether this the best module around incorporating dc-dc step down and low voltage cut-off (in terms of reliability, voltage stability, efficiency / battery drain)?Many thanks.

author: tooki
author_rank: Super Contributor
timestamp: February 28, 2022, 11:20:29 pm
content: Please edit your post to clarify what you need: step-up (boost) or step-down (buck)? You say one first and the other later.

author: Terry Bites
author_rank: Super Contributor
timestamp: March 01, 2022, 04:21:12 pm
content: I commend to you Texas intruments WEBENCH® POWER DESIGNER. Its very handy.
Efficient off-the-shelf laser diodes (preferably Fabry-Perot) - Page 1
Forum section: electronics / projects

author: kcant
author_rank: Newbie
timestamp: December 05, 2023, 06:32:53 pm
content: Does anyone know of any Fabry-Perot lasers with decent (>50%) efficiency that are available off-the-shelf? Wavelength isn't important, although I assume they'd be red/infrared.

author: ejeffrey
author_rank: Super Contributor
timestamp: December 05, 2023, 07:13:13 pm
content: Thorlabs sells a wide variety of visible and NIR laser diodes:https://www.thorlabs.com/newgrouppage9.cfm?objectgroup_id=4737With reasonably good data sheets for all of them. Some of them will exceed 50% efficient, at least electrical power -> optical power. Getting 50% wall plug efficiency is difficult as the driver circuit will have losses, and many diodes need to be cooled to maintain their best performance and the cooling consumes power as well.
EFM32 Loader: a GUI and CLI utility for EFM32's UART bootloader - Page 1
Forum section: electronics / projects

author: msr
author_rank: Regular Contributor
timestamp: July 16, 2015, 03:40:55 pm
content: Hi everyone,Is anyone here using EFM32 microcontrollers?I've been doing mostly sensor-based systems and I think these microcontrollers are the perfect fit. ARM Cortex (they go from M0 to M4, and their series seem to keep growing), an architecture that was specially designed for low-power sensor-based embedded systems, allowing to measure "stuff" while the CPU is stopped, a nice set of peripherals (OPAMP, 12bit DAC and ADC), great support for GCC ARM Embedded (which makes them really ease to use or getting started to) and a factory-programmed UART bootloader.The bootloader uses XMODEM-CRC protocol and TeraTerm may be used for uploading. However if you want a command-line tool (like "avrdude" for AVR microcontrollers), there's anything you can use. So, I built one.I wrote a bit more about it on my blog:http://theramblingness.com/2015/07/16/a-gui-and-cli-utility-for-efm32s-uart-bootloader/The source code is on Github:https://github.com/cidadao/efm32_loaderAnd the download of a windows executable, ready to use, is available here:https://github.com/cidadao/efm32_loader/releasesHope this is useful! Feedback is very welcomed.

author: funkathustra
author_rank: Regular Contributor
timestamp: July 19, 2015, 12:56:00 am
content: Cool stuff! I'm just about to start a little hobbyist project built around an EFM32, so i'll definitely check this out!It looks like a really underrated platform, so I'm excited to get into it.

author: msr
author_rank: Regular Contributor
timestamp: July 20, 2015, 03:41:19 pm
content: Quote from: funkathustra on July 19, 2015, 12:56:00 amYep. Many people seems to struggle finding a good and free toolchain for ARM microcontrollers (I think getting the linker scripts and startup code is usually the biggest issue). EFM32 provides all that and also a nice peripheral library (called "emlib"). For low power/sensor-based systems these microcontrollers are great and the starter kits are also cheap. So, it's a no-brainer IMO.(disclosure: I haven't any connection with Silicon Labs, I'm just an enthusiastic user)Let me know if you find any issue with the EFM32 Loader.

author: msr
author_rank: Regular Contributor
timestamp: September 30, 2015, 11:18:16 am
content: Hey guys,Just to let you know that EFM32 Loader was updated and it now supports uploading through the USB (CDC) bootloader as well.You may download the executable for windows here:https://github.com/cidadao/efm32_loader/releasesRemember that this can be used as GUI or CLI so it can be easily integrated with your own (production) tools
EG8011 vs EG8010 Inverter ASIC - Page 1
Forum section: electronics / projects

author: theoldwizard1
author_rank: Regular Contributor
timestamp: May 21, 2021, 01:55:20 pm
content: EG Micro came up with a slick little ASIC a few years back the does DC to AC inversion, the EG8010. It can be used in a high frequency/high input voltage design OR a low frequency/low input voltage design. Combined with some MOSFET driver (IR2110) it has made pure since wave inverters almost as cheap as modified sine wave inverters !(This combination is sold on a small plug in board called a EGS003. Under $10 on eBay.)Well no EE can "leave well enough alone" so recently the have come up withe the EG8011. The problem is, the spec sheets have not been translate to English yet ! Here are some of the differences.50, 60, 400 or 0-100 Hz outputPWM output (think Class D amplifier) 10 or 20 kHzSoft startDead zone controlI am looking for ENLIGHTENMENT on the Dead Zone Control. This is what the Google translation say.Quote

author: theoldwizard1
author_rank: Regular Contributor
timestamp: May 30, 2023, 01:10:37 pm
content: No interest in inverter designs ?

author: moffy
author_rank: Super Contributor
timestamp: May 31, 2023, 12:22:09 am
content: It looks like you have answered your own question rather well, nothing really to add.

author: schmitt trigger
author_rank: Super Contributor
timestamp: May 31, 2023, 03:11:57 am
content: Such that we can answer your question accurately, exactly what do you require to be enlightened about?-The reason why the deadtime is necessary?-Method(s) to implement deadtime?-How to determine the optimal deadtime?-Other questions or concerns related to deadtime?