hybridfree/eevblog-posts huggingface dataset:
Lithium BMS compatibility  - Page 1
Forum section: electronics / beginners

author: maks_3
author_rank: Newbie
timestamp: May 07, 2025, 02:29:02 am
content: Hello, I have this cheap battery powered (2 18650s) air compressor that was very weak and couldn't even fully inflate one tyre, but that did accurately record and allow me to set the pressure. Therefore I'm planning to use the motor wires to trigger a solid state relay that will turn on a bigger motor and compressor that will be powered by 3S 18650s cells (with as many parallel as are needed). The problem however is that the easiest way to power the board from the weak compressor is to connect it (with balancing) to 2 of the 3 sets of cells, the board itself will use next to no power and the BMS that will be attached to all 3 sets of cells in series obviously has it's own balancing. The problem is I don't know if the resistance of the integrated compressor board BMS (Which connects to 2 18650s in series) will affect how the 3S BMS measures the voltage and does the balancing of all the cells.I appreciate any help,Thanks

author: ledtester
author_rank: Super Contributor
timestamp: May 07, 2025, 02:44:28 am
content: You can convert the 3S voltage to a 2S voltage using a DC/DC converter or even a linear regulator if the air compressor really doesn't use a lot of current. This approach would put an equal load on the 3S pack.It's also possible that the logic circuitry of the 2S-powered air compressor will run fine on a higher voltage -- such circuitry usually runs at voltages such as 5V or 3V and so need voltage regulators/converters to convert the higher 2S voltage down. Verifying this would require careful examination of the compressor's logic section.Or -- just power the original air compressor from a 2S pack and your bigger one from a separate 3S pack - that could be the simplest solution.A question: besides via the 2S battery pack can the compressor be powered by an AC adaptor?

author: maks_3
author_rank: Newbie
timestamp: May 07, 2025, 06:51:41 pm
content: I agree with you that would probably be the most proper way of doing it, and as all that is being powered is an led display and basic processing it could use a small converter, but it would still take up some space which I am trying to minimise if possible and as it has a 4.2v balance connection I would need 2 of them I think.I'm basically trying to get the power of a big wired 12v air compressor with the portability (absence of annoying cables) and accurate pressure control of the battery powered compressor. Ive also bought a 3s type c fast charger to make it convenient to charge and I think adding 2 sets of cells would complicate this
Lithium charging module advice (2S) - Page 1
Forum section: electronics / beginners

author: algorithm
author_rank: Regular Contributor
timestamp: July 24, 2024, 05:24:27 pm
content: Anybody have any expertise / experience with dual cell charging circuits?Is there an optimal ideal? Im unsure if a balanced charge module is worse than a normal 2S module. I did see (years ago now) someone said the balanced 2S module wouldnt ever actually balance it evenly, one cell would be off by a slight margin. Though maybe thats still best? Any advice or comments would be appreciated.I have a simple project requiring 2 cells at 7.2v and I have both types of 2S modules so just need to decide a winner.

author: Peabody
author_rank: Super Contributor
timestamp: July 24, 2024, 05:33:43 pm
content: I don't know, but would appreciate it if you would post links to the two types you have.

author: thm_w
author_rank: Super Contributor
timestamp: July 24, 2024, 10:56:58 pm
content: Many discussions exist on this already.The "optimal ideal" would be a balanced charger or a balanced BMS. In reality you can get away without if the cells are well matched.https://www.eevblog.com/forum/beginners/im-looking-for-true-independent-2-cell-charging-chip/
lithium ion battery charging Baofeng - Page 1
Forum section: electronics / beginners

author: mkube396
author_rank: Regular Contributor
timestamp: April 12, 2018, 12:20:39 am
content: So i have 3 chargers 1 of them is busted.. I would like to make a circuit that will charge the lithium ion battery pack's for the radios.They are 7.4v Li-ion 1800mAh to 3800mAh but more like 2600 i would guess you know "China".From how simple the circuit is in the charging base i guessing there just dropping the voltage from 10V to 8.4v from pics on the internet of the battery's that are open it looks like they have a circuit board in with the battery's for Controlling the charge? Can i just put a Simple voltage reg in there to drop 10 or 12V down to 8.4v?and is there away to add a done charging LED?

author: Audioguru
author_rank: Super Contributor
timestamp: April 12, 2018, 12:56:07 am
content: A lithium battery explodes or catches on fire if charged wrong. You are guessing about the little board on the battery that might not be a charger circuit.A charger circuit limits the charging current and detects it dropping low then disconnects the charging. The charger also regulates the charging voltage and many of them sense over temperature then disconnects the charging. A battery discharged too low must be charged with a current much less than normal and its voltage is monitored. If the voltage rises then soon it is normally charged but if the voltage stays low then the charge is disconnected. Multi-cell batteries (7.4V to 8.4V have two cells)are balanced charged.

author: mkube396
author_rank: Regular Contributor
timestamp: April 12, 2018, 01:00:17 am
content: that a look at the pics... I don't think them 2 10ohm resistors are doing all that work..In this video you can see the inside from what it looks like it is balanced charged

author: mkube396
author_rank: Regular Contributor
timestamp: April 14, 2018, 12:53:31 pm
content: will this work?https://www.ebay.com/itm/TP5100-1S-2S-3-7V-7-4V-Lithium-Lipo-Li-ion-18650-Battery-Charger-Charging-Module/322655498326?epid=2163906507&hash=item4b1fc43056:g:6x0AAOSwfDhZgxLf&rmvSB=true
Lithium Ion battery indication by led through voltage measurement    - Page 1
Forum section: electronics / beginners

author: Vindhyachal.takniki
author_rank: Frequent Contributor
timestamp: June 12, 2018, 04:28:38 am
content: 1. Have to make a led level indicator of lithium battery of 7.4V (two cells in series of 3.7V each).Led level indications are 0-20,40,60,80 & 100% i.e by 5 leds.2. Need to make it simple by voltage measurement only. Voltage range of battery pack is 5.7V to 8.4V. Need to break that into 5 different voltage ranges & then indicate by led.3. I know voltage measurement is not accurate way, but in most application its good enough & I ave to keep simple in this application.4. Currently doing it by MSP430G2553 MCU & its working fine, but I was thinking is there any dedicated IC available for this, need to be real low power?Problem with MCU is everytime I have to burn program in it.Check lots of chinese power banks, they have some dedicated IC, but there parts number are not traceable or available on net.Any low power ic solution for this?

author: Nusa
author_rank: Super Contributor
timestamp: June 12, 2018, 04:44:19 am
content: Search for "bar display driver".

author: JohnnyMalaria
author_rank: Super Contributor
timestamp: June 12, 2018, 04:46:00 am
content: How about something like this (it's a kit):https://www.tindie.com/products/kuzyatech/lm3916-led-bargraph-vu-meter-pick-your-color/

author: sleemanj
author_rank: Super Contributor
timestamp: June 12, 2018, 05:14:28 am
content: https://www.maximintegrated.com/en/products/power/battery-management/DS2788.html(that was the first result for googling "battery fuel gauge IC led display", there are more)

author: Vindhyachal.takniki
author_rank: Frequent Contributor
timestamp: June 14, 2018, 04:23:25 am
content: 1. I need a switch also, when it is pressed led should indicate for 2-3 seconds.2.Maxim IC is bit expensive.3. Can we intergrate switch with LM3916 also, so that when switch is pressed only then led are glown for 2-3 seconds, then again everything goes into low power mode

author: mikerj
author_rank: Super Contributor
timestamp: June 14, 2018, 08:37:04 am
content: TheBQ34Z100-G1is an impedance based fuel gauge IC which is about half the price of the Maxim part. Note that the LM3916 bargraph driver is obsolete.

author: krish2487
author_rank: Frequent Contributor
timestamp: June 14, 2018, 09:12:56 am
content: A little homework can go a long way in helping you yourself...Its not hard to take away from the wonderful video dave made ages ago and make a 5 step bar graph or whatever you would like to do..
lithium ion battery types - Page 1
Forum section: electronics / beginners

author: m3vuv
author_rank: Super Contributor
timestamp: September 17, 2021, 10:37:54 pm
content: hi foks,this guy has the same bms app as me,check out the different battery chemistry types on the app screenshot ,i know what most of the battery chemistry types are but wtf is polymer light?,its a new one on me can anyone explaine?,tia.

author: Jwillis
author_rank: Super Contributor
timestamp: September 18, 2021, 10:55:58 pm
content: Maybe it refers something like thishttps://www.sparkfun.com/products/13852or thishttps://www.powerstream.com/ultra-light.htmCan't find the video. Do you have a link to it?

author: m3vuv
author_rank: Super Contributor
timestamp: September 19, 2021, 12:48:41 pm
content: here you go

author: Jwillis
author_rank: Super Contributor
timestamp: September 19, 2021, 03:40:20 pm
content: What I'm understanding is that LiFepo Normal and LiFepo Light are Factory preset parameters of the BMO . Normal would be for general charging and operation of the battery and light would be lowest recommended parameters of the battery. The two presets are cautionary to prevent damage to the battery or BMO . Setting some parameters to low can have just as many adverse effects as settings being to high .Manual.For example3.3.2 Delta to balanceThe BMS will not balance unless the delta exceeds this level. Setting this value too coarse will result inpossible cell damage;setting this value too fine will result in the BMS dissipating considerable heat as itattempts to equalize the cell voltages. Recall that the passive balancing circuit works by routing the excessvoltage into resistors within the BMS, which converts into heat. This value must be a compromise betweenthose two extremes. Please see the recommended values in Appendix A.Hope this helps
Lithium Ion Battery Upgrade Question - Page 1
Forum section: electronics / beginners

author: markferrino
author_rank: Newbie
timestamp: June 14, 2023, 05:13:27 am
content: I'm pretty new to this.I have a voice recorder with a 3.7v 850mah lithium ion battery. I'd like to solder in an upgraded replacement that has a capacity of 2000mah (also 3.7v).Afterwards when I plug it in to charge, will it charge the new battery to full, or do similar such devices typically include something that governs/limits the amount of charge to that of the original installed  battery (i.e. programming in the ic, for example, etc)?

author: JohanH
author_rank: Frequent Contributor
timestamp: June 14, 2023, 06:47:41 am
content: I've done this on a couple of devices and it's worked fine. It's unlikely that such devices monitor battery capacity. But you probably won't know until you try.

author: MrAl
author_rank: Super Contributor
timestamp: June 14, 2023, 12:41:01 pm
content: Quote from: markferrino on June 14, 2023, 05:13:27 amHi,Just make sure you get a battery with welded on tabs don't solder to the battery. You can then solder to the tabs.

author: BradC
author_rank: Super Contributor
timestamp: June 14, 2023, 12:47:03 pm
content: As other have said, it'll be fine. It'll take longer to charge and it'll run for longer. I've even put upgraded cells in a laptop that has the capacity hard coded into the BMS. It just takes longer to reach 100% and it sits at 100% until it discharges to about the original capacity, then starts to drop off. Strange, but does the job.

author: AndyBeez
author_rank: Frequent Contributor
timestamp: June 14, 2023, 05:49:01 pm
content: Open up the target board and take a look at what chip is providing the charge control function. Most charge control chips including the jellybean TP4056 set maximum charge current with a programming resistor (RPROG). For a bigger battery capacity you might be able to up-rate RPROGat the same time.

author: markferrino
author_rank: Newbie
timestamp: June 15, 2023, 10:10:02 am
content: Thank you all for your help. I'll give it a shot and see how it goes.@MrAl I'll be sure to solder to the tabs of the battery@AndyBeez Way beyond my understanding, but appreciate your advice nonetheless.
Lithium Ion cells for high temperature operation - Page 1
Forum section: electronics / beginners

author: Vindhyachal.takniki
author_rank: Frequent Contributor
timestamp: September 03, 2017, 07:54:35 am
content: 1. Need to use Lithium Ion batteries around 220mAh & 2000mAh types, in temperature range of -40C to 85C.Any known manufactures?2. One is tadrian, another EVE battery has upto 60C3. Any other manufacturer?
Lithium on silicon?  - Page 1
Forum section: electronics / beginners

author: algorithm
author_rank: Regular Contributor
timestamp: June 22, 2022, 10:22:59 am
content: So, replaced a transistor, but lacking proper heat sink compound I in my ignorance used the only grease I had, lithium. Only months later did I think "that might eat that". Will it eat that plastic encasement? If so what sort of time frame? Any hope of cleaning it off and applying proper grease? Or will that part be wanting to fail sooner than usual? like a loose bolt rubberless shopping trolley wheel. Replacing it isnt a big deal if so. Thanks

author: T3sl4co1l
author_rank: Super Contributor
timestamp: June 22, 2022, 11:33:52 am
content: Plastic.... the transistor package you mean? Nah it's epoxy, not much short of fuming nitric acid eats it.FWIW, anything is better than nothing; lithium grease isn't the worst thing you could've put in there, and if it's not running near limits, it's probably fine. (What's the worst thing, then? Air!)Tim

author: algorithm
author_rank: Regular Contributor
timestamp: June 22, 2022, 12:16:14 pm
content: Schwoo, thats a relief. I thought about that, but wasnt sure if the lithium could degrade it after enough time. But good point about the standard in decapsulation, I should have thought of that, because nobody decaps with lithium grease lol. Thanks for the confirmation t3sl4co1l
lithium polymer battery 3 cell whats it's cut off voltage - Page 1
Forum section: electronics / beginners

author: amateur_25
author_rank: Regular Contributor
timestamp: December 13, 2017, 10:30:17 am
content: HiI watched daves video on charging lithium ion/polymer batteries. However he was dealing with a single cell.I have 3 cell battery.Assuming 2.7v is when the cells are dead, would it then be 8.1v I would deem the battery dead at?

author: paulca
author_rank: Super Contributor
timestamp: December 13, 2017, 10:48:55 am
content: Quote from: amateur_25 on December 13, 2017, 10:30:17 amBelow 3V per cell the voltage will RAPIDLY collapse under load. Therefore it is usually not recommended to take them below 3.0V, 2.9V absolute minimum. RC Heli's and models I fly have a soft cut set around 3.3V where they start to limit the current which gives you a warning and lets you land. They hard cut at 3V and in a plane you glide to a dead stick landing, in a heli, unless you are really good at autp-rotation, you crash.Manually doing the cut off is not recommended as it will drop incredibly fast under any kinda of load. You should use a cut off circuit or as a minimum an audible alarm.I was testing using a 3S 5000mAh pack at the weekend to charge USB devices via a regulator. The regulator had an LED volt meter. It was reading 9.8V feeding about 1A to a USB power bank. I went to the kitchen to get a cup of coffee and when I came back, literally 3 minutes later the voltage was descending rapidly though 5.8V. I immediately charged it back up above 9V on very limited current of 1/20th C (250mA).Also note it is not the pack voltage you should be concerned with but the individual cell voltages. If the pack is not perfectly balanced and matched, because the voltage collapses so fast you can get into a situation where the pack is producing 9V but that is made up of two cells at 3.5V and one at 2V. That 2V cell will be under considerable stress!What is your use case out of interest and I might be able to help.

author: amyk
author_rank: Super Contributor
timestamp: December 13, 2017, 11:53:10 am
content: The cutoff voltage you should use depends on the current --- at low discharge rates, something closer to the manufacturer's recommended minimum is OK, but when discharging quickly (common situation with RC, as explained by poster above), the cutoff should be higher. This has to do with the internal resistance of the cell.

author: David Hess
author_rank: Super Contributor
timestamp: December 13, 2017, 05:35:34 pm
content: Quote from: amateur_25 on December 13, 2017, 10:30:17 amYes but ... if one cell has less capacity than the other two, then its voltage will fall first and it may for example reach 1.5 volts with an 8.1 volt cutoff applied to 3 cells.If it was a high reliability application, then I would monitor the voltage of every cell during discharge so that no cell falls below its discharge cutoff point.
Lithium protection circuit  - Page 1
Forum section: electronics / beginners

author: lutkeveld
author_rank: Regular Contributor
timestamp: March 31, 2015, 04:29:52 pm
content: I'm working on a PCB that will get its power via a 3S lipo pack. I want it to be a all-in-one module, so protection will be handled by the board.Requirements: 4A min output, low voltage cutoff, balancing, low BOM count/cost.Something like this module:http://www.ebay.com/itm/3-cells-4A-w-balancing-Li-ion-Lithium-18650-14450-Battery-Input-Ouput-Protection-/111526325783?pt=LH_DefaultDomain_0&hash=item19f77cae17Can't find a schematic that matches my requirement. Does anybody have input on this?

author: Neilm
author_rank: Super Contributor
timestamp: March 31, 2015, 06:10:50 pm
content: Have a look at the TI website. There are quite a few chips that do this there

author: bills
author_rank: Frequent Contributor
timestamp: March 31, 2015, 06:29:39 pm
content: I bought some of these they work with 3 or 4 cells,seem to be ok and quite small.http://www.ebay.com/itm/181681937061?_trksid=p2059210.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

author: lutkeveld
author_rank: Regular Contributor
timestamp: March 31, 2015, 07:14:52 pm
content: Neilm Only one that seems to fit my requirements at a quick glance is the BQ76920. Don't know what's up with the 'companion controller' though?Bills, Doesn't fit my requirements and I'm not looking for a ready-made product. I'm looking for a schematic to intergrate into a PCB.A lot of the blue ebay protection boards that fit my requirements seem to use Seiko IC's, but on their site I can't find them.

author: juanfermed
author_rank: Regular Contributor
timestamp: July 05, 2016, 10:30:35 pm
content: Hey lutkeveld,The BQ76920 seems a nice fit and very simple. This is a somewhat old post but if you have not made a choice, you should be able to do it with this one. The "companion controller" is nothing more than an external MCU, whichever you want, that must take care of things like disconnecting the battery when the BQ76920 triggers an alarm. This chip also has some automatic protection functions like overvoltage and undervotage, but other things like over current, temperature protection, short circuit protection and constant monitoring should be done by an external "companion controller".For the price, it is a nice chip.
LITTLE CRACKY - Page 1
Forum section: electronics / beginners

author: Abayomi
author_rank: Contributor
timestamp: September 10, 2016, 09:44:08 pm
content: I need an experience answer on how to hold the logic level of a digital circuit and change the level at leisure. This due to the fact that I want to control three 7447 (7-segment decoder) switching between each decoder without affecting the previous decoder

author: SL4P
author_rank: Super Contributor
timestamp: September 11, 2016, 10:54:31 am
content: Quote from: Abayomi on September 10, 2016, 09:44:08 pmI think you need to elaborate a bit more so we can understand your problem!

author: Kilrah
author_rank: Unknown
timestamp: September 11, 2016, 11:45:42 am
content: A latch?

author: Chris Mr
author_rank: Regular Contributor
timestamp: September 11, 2016, 11:46:20 am
content: The 'old standard' way would be to use a latch in between the data and 7447, one latch for each 7447 with common data input.These days the 'old standard' way is old and not very standard at all - you would be more likely to use an LED driver and a micro-processor; but it could be that such things are not available to you?Where is the data coming from and what makes it change

author: Brumby
author_rank: Unknown
timestamp: September 11, 2016, 11:50:00 am
content: Quote from: SL4P on September 11, 2016, 10:54:31 am+1OP - your description is very vague. We can't figure out what you actually want to do ... which means there's no way for us to help you.More information is needed.

author: PA0PBZ
author_rank: Super Contributor
timestamp: September 11, 2016, 11:54:44 am
content: I *think* he has one BCD output which he wants to send to 3 different displays. I'd suggest a 4543 which is a decoder + latch. That way you can just latch in the data for one of the 3 displays when you feel like it.http://www.nxp.com/documents/data_sheet/HEF4543B.pdf

author: Ian.M
author_rank: Super Contributor
timestamp: September 11, 2016, 11:55:13 am
content: Probably related:https://www.eevblog.com/forum/projects/synchronous-counter/It looks like the O.P. may have anXY problemHe definitely needs a better question, e.g:"How can I store and display three decimal digits on three 7 segment displays using 74xx series logic?",and to add some constraints (e.g: fewest chips, or as cheaply as possible, or using easily available parts) and specify how the decimal digits will be presented to his circuit, and what is to trigger storing each of the current digits.However, even that may still be too close to the problem and stepping back and giving us a description of the overall purpose of this project would help steer this topic towards usable solutions
little doubt FY6900 60mHz by FY6900 20mHz - Page 1
Forum section: electronics / beginners

author: Adrian_Arg.
author_rank: Frequent Contributor
timestamp: September 17, 2019, 04:40:35 pm
content: I have little doubt, I have a KMOON FY6900 60mhz a month ago, and a good friend buys it for me at a price plus 10% that pays for more shipping costs, since I need it, and I think since I only use it for adruino and small electronic projects, with a Kmoon FY6900 20mhz, it reaches me and I am left with a few dollars in my favor, or should I keep the 60mhz one that is the only difference with that of 20mhz?

author: Jwillis
author_rank: Super Contributor
timestamp: September 19, 2019, 03:08:17 am
content: Keep them both .You can always use one to modulate the other with the external input.

author: Adrian_Arg.
author_rank: Frequent Contributor
timestamp: September 19, 2019, 03:57:22 pm
content: I already did business, I sold the Kmonn FY6900 60mhz at the price of $ 110, and I bought a Kmoon FY6900 20mhz at the price of $ 71 free shipping, mine is the hobby, only the sine wave is 60mhz, the Square wave arrives quite well until 15mhz, I used it with low frequency, now I'm happy I have $ 40 for beer and a new generator on the way.

author: Yansi
author_rank: Super Contributor
timestamp: September 19, 2019, 04:07:21 pm
content: I have little doubt you know what the difference between mHz and MHz is.

author: Adrian_Arg.
author_rank: Frequent Contributor
timestamp: September 19, 2019, 05:16:49 pm
content: Quote from: Yansi on September 19, 2019, 04:07:21 pmMHz, KHz, Hz, mHz, μHz
Little help with an H-Bridge driver pls - Page 1
Forum section: electronics / beginners

author: RossK
author_rank: Contributor
timestamp: January 15, 2013, 06:11:03 am
content: I'm trying to setup a half H-Bridge drive for DC motors (10v-18v and 10A-50A), i'm expecting to drive them from a PWM signal in the 30-40kHz range (i'm open to being convinced otherwise, but i need to keep in the ultrasonic range 24kHz+).I'm looking at this driverhttp://www.mouser.com/ds/2/405/slusaf9a-120356.pdfand these N channel MOSFETshttp://www.mouser.com/ds/2/302/PSMNR90-30BL-104176.pdfThis is my first project with MOSFETs and i'm feeling a littleand a lotI believe I will need to include schottky diodes and a cap across the bridge to manage ripple - my questions are:* Will this bridge drive these fets successfully?* My attempt at mathing this out estimates that aprox 1.14A is needed to drive the fets at their rated turn-on time... will current limiting resistors be needed?* What is the minimum and maximum duty cycle this bridge can be run at to keep the high-side driver operating? and how the heck did you answer this question?Thanks a bunch!

author: Kremmen
author_rank: Super Contributor
timestamp: January 15, 2013, 08:04:57 am
content: Quote from: RossK on January 15, 2013, 06:11:03 amNot necessarily trying to convince you, but still. DC motors are usually driven at significantly lower frequencies, like 500 Hz or even below. If the motor absolutely needs to be silent then i guess you must drive it beyond the hearing range. That however will require more attention to the components and circuits used for drivingQuoteThose should work. The total gate charge of the FET is a bit on the high side at 243 nC, but at this low a switching frequency it won't really matter. A quick calculation makes the average gate current just 11 mA so no worries there.QuoteBut if/when it works you'll feel %-BQuoteYou already have substrate diodes across the bridge inside the FETs. The datasheet even give specs and the reverse recovery time is 67 ns and charge is 123 nC - that is a fast diode, i.e. no problem and you do not need anything else.- Yes, it will drive the FETs- Yes, do include gate resistors. Heavy overdriving causes ringing in the FET - you don't want that. Off the cuff 100 ohms and adjust as needed,- the minimum and maximum duty cycles can be calculated from the steady state current drain of the gate circuit vs the capacitor available to supply the voltage. MAx duty is the time the cap is able to maintain Vg at saturation level and min duty is zero (unless i forget something that affects it).
Little reference book produced by Texas Instruments - Page 1
Forum section: electronics / beginners

author: casinada
author_rank: Frequent Contributor
timestamp: March 03, 2015, 03:37:35 pm
content: https://www.ti.com/seclit/ml/slyw038a/slyw038a.pdfEnjoy

author: codeboy2k
author_rank: Super Contributor
timestamp: March 04, 2015, 09:50:48 am
content: That will be a nice reference if TI gave it out for free(like they used to give out their old databooks and design guides and reference series)As a PDF, it's also poorly done, since they didn't make the table of contents clickable, nor did they make any HTTP links clickable.However, these days, everything in there can be found quickly via a web search, rather than paging up and down through a PDF.I've got a desktop indexer running, so my local PDF's are searched first, which does help when I have so many PDFs and datasheets stored locally these days.

author: malch
author_rank: Regular Contributor
timestamp: March 05, 2015, 05:39:50 am
content: Printed it out. very good!

author: sainter
author_rank: Regular Contributor
timestamp: March 05, 2015, 06:04:58 am
content: Very handy. Thx for posting it, and thx TI for making it

author: casinada
author_rank: Frequent Contributor
timestamp: March 05, 2015, 07:31:00 am
content: They have lots of good stuff, here is another example:http://www.ti.com/lit/an/sboa092a/sboa092a.pdfDo a search of OP Amps for Everyone by Ron Mancini. There are many versions. There are free versions published directly by TI.There are lots of application notes that you can find in the TI site but they were originally National Semiconductors material.

author: codeboy2k
author_rank: Super Contributor
timestamp: March 05, 2015, 08:16:46 am
content: Ron Mancini's book is a must have.Also, the little pocket reference is pretty good too, it definitely has lots of useful information there. I didn't mean to detract from it's value.Even though I have plenty of books and PDFs and pocket reference guides in my immediate reach, I still find it faster to search it online.For the past 5 years I've been systematically reducing my books and anything else on paper.The next time I move, I want to take my bookshelf with me on a hard drive

author: magetoo
author_rank: Frequent Contributor
timestamp: March 06, 2015, 09:59:19 pm
content: Quote from: casinada on March 03, 2015, 03:37:35 pmAnd for anyone who hates blindly following links as much as I do, that goes to the "Analog Engineer's Pocket Reference".

author: Obin
author_rank: Contributor
timestamp: March 31, 2015, 05:43:42 pm
content: Nifty little book
LKG Industries kit 80-065 varactor tuned FM transmitter - Page 1
Forum section: electronics / beginners

author: tlu
author_rank: Regular Contributor
timestamp: October 08, 2012, 04:27:20 pm
content: Hi All,Has anyone order this kit and tried to build this FM transmitter? The kit I received has parts that are not longer supplied with the original diagram. One of these is the varactor which is replaced by a PN2222 transistor with one of it's legs cut off. The second is an MV209 which is a tunable inductor and now the kit supplies a core with wires which you have to manually wrap around with 7 turns.I started to put this together on a breadboard instead of the supplied pcb to see if it will work or not. However I'm not getting any luck. Just asking to see if others on here have played with this kit.

author: Tube_Dude
author_rank: Regular Contributor
timestamp: October 08, 2012, 04:51:50 pm
content: Quote from: tlu on October 08, 2012, 04:27:20 pmHiA breadboard is not ideal for very high frequency circuits ~100 MHz. Too much parasitic capacitance and inductance.Try it in the supplied PCB, where, wishfully, every parasitic had been taken in account and your luck will change...

author: tlu
author_rank: Regular Contributor
timestamp: October 08, 2012, 09:10:34 pm
content: Hi Tube Dude,Thanks for the advice. The instructions are terrible with this kit. The tuning varactor is being made with an NPN 2222A transistor with one of its leg cut off. It is not clear with leg should be grounded in the instruction and on the supplied pcb it looks like it can go both way since the silkscreen has no indication.Should the base of it go to ground? It looks like either the emitter is cut off according to the pin out for it on a datasheet I'd looked up.Tim

author: SeanB
author_rank: Super Contributor
timestamp: October 08, 2012, 09:27:42 pm
content: Should be reverse biased to act as varicap diode. Base to ground.

author: tlu
author_rank: Regular Contributor
timestamp: October 09, 2012, 09:22:26 am
content: Thanks SeanB
LLC resonant wireless charger feedback problem - Page 1
Forum section: electronics / beginners

author: cetintas
author_rank: Newbie
timestamp: April 09, 2020, 06:04:21 pm
content: Hello everyone, I am currently designing an LLC resonant converter for my graduation project. I use FAN7631 as frequency control IC. In application, voltage feedback is taken from secondary with an optocoupler. But, result of primary and secondary are seperated I can't use an optocoupler system for closed loop. I can't figure out and couldn't find any solution for that. I will be appreciate if you help me to make it closed loop. I consider to use auxilary winding but I don't know how to use it.

author: Manul
author_rank: Super Contributor
timestamp: April 09, 2020, 06:26:43 pm
content: Is closed loop a must? I mean you MUST do it? Ok, then one thing that comes to my mind is to sense a voltage on a secondary side and use some kind of load modulation. That load modulation can be sensed on the primary, decoded and used as feedback.But that might become complex to get right.

author: Manul
author_rank: Super Contributor
timestamp: April 09, 2020, 07:06:34 pm
content: Found this:https://www.analog.com/en/technical-articles/close-the-loop-between-wireless-charger-receiver-and-transmitter.html
LLC topology driving methods and output inductor - Page 1
Forum section: electronics / beginners

author: AstRii
author_rank: Newbie
timestamp: February 23, 2024, 02:52:39 am
content: Hello,I've recently discovered LLC switch mode power supply topology which I have studied ever since, however I have a few questions for which I have not found an answer or I have failed to understand:LLC converters seem to be always using a frequency modulation to set the output power, however the efficiency drops when the converter runs away from the resonance.Wouldn't it be better to always drive it in resonance but skip switching pulses to module output power? I believe this method is called "bang-bang" control (please correct me if I'm wrong).Or perhaps always drive it in resonance but limit the duty cycle of the transistors?What would be the advantages/disadvantages or these control methods?I have also noticed the LLC power supplies do not use any output inductors as most power supplies do.They just rectify the output from the transformer and feed that directly to an output capacitance.Doesn't this yield a poor power factor? Wouldn't current flow just near the peaks of the secondary voltage (also leading to big output ripple)?One other thing I have failed to understand is how phase shifted full bridge achieves ZVS.I will be thankful for any answers

author: Konkedout
author_rank: Frequent Contributor
timestamp: February 23, 2024, 04:55:23 am
content: I think your questions require answers that would be at least a long chapter in a textbook; more than most forum participants would want to write.I have only had brief exposure to LLC converters but I think that your missing piece may be some controlled amount of transformer leakage inductance.

author: johansen
author_rank: Super Contributor
timestamp: February 23, 2024, 06:03:40 am
content: I think what textbooks fail to teach is that to transform a range of voltages into another voltage requires energy storage.LLC converters just store that energy in a resonant state with an inductor, in order to achieve better switching transitions, so when you change the frequency in order to change the power transfer, or the output voltage, the switching transitions become more difficult because the turn on and turn off current has increased (perhaps significantly) from the ideal situation in which ZCS or ZVS or both is the intended full load condition.Pulse skipping at full resonance condition would still involve weird start up conditions which might destroy any efficiency improvements. Also the output would have low frequency ripple..
LM 317 0v - Page 1
Forum section: electronics / beginners

author: Scarionn
author_rank: Contributor
timestamp: May 23, 2012, 02:25:53 pm
content: How can I go down 0v with a LM317?

author: Bored@Work
author_rank: Super Contributor
timestamp: May 23, 2012, 02:40:56 pm
content: By following the procedure in the datasheet, or by using a better device.

author: Scarionn
author_rank: Contributor
timestamp: May 23, 2012, 09:11:16 pm
content: I can't have a negative rail in my project, and de LT3080 is rare in my cuntry. Do you no where can I buy the LT3080?

author: Zero999
author_rank: Super Contributor
timestamp: May 24, 2012, 12:56:39 am
content: The LT3080 also requires a negative power supply to work down to 0V. It has a 0.5mA minimum load current, which needs a negative power supply, at 0V.Fortunately, there are ways to get a negative supply from a positive supply. How are you powering the circuit? Are you using mains or a battery?

author: Scarionn
author_rank: Contributor
timestamp: May 24, 2012, 02:45:11 am
content: I'm powering my cirquit whit the mains. I'm powering my cirquit with 24v (12+12).

author: nick.sek
author_rank: Regular Contributor
timestamp: May 24, 2012, 03:16:47 am
content: This is one way to approach it, but I got to agree with the boys here; offsetting it with a negative voltage is the best approach; as it will offer more stability:But if you have two 12 volts sources you are in luck, because you can make a relevant negative voltage to offset the LM317:

author: amspire
author_rank: Super Contributor
timestamp: May 24, 2012, 03:21:11 am
content: Quote from: Scarionn on May 24, 2012, 02:45:11 amIf there is a transformer, there are always ways to get an extra low current negative supply such as this:Richard.

author: Psi
author_rank: Super Contributor
timestamp: May 24, 2012, 04:29:59 am
content: If you only need low current you can always put a voltage divider on the output of the LM317.Can't get to zero but you can get it down quite far.Obviously you then need a higher input voltage to get the same output.

author: Zero999
author_rank: Super Contributor
timestamp: May 24, 2012, 09:51:48 am
content: The following thread gives some examples:https://www.eevblog.com/forum/beginners/zero-volts-from-a-lm-317/
lm 317 tip 3055 constant current - Page 1
Forum section: electronics / beginners

author: rahulrahullll
author_rank: Contributor
timestamp: November 26, 2017, 10:45:30 pm
content: i am using this circuit------working ----------------circuit exact same as above---few----modifications--done----i am using 0-40 v ac transformer---5a---using tip 3055 plastic package----10 ohm/10 w resistor------sharing current concept lm 317 and tip 3055----------As current starts to flow through the 10 ohm resistor, a voltage drop will appear across it. When this voltage drop is higher than 0.6 volts, the 2N3055 starts to conduct and supply current to the output of the power supply. This starts happening when the IC LM317 is outputting 60 mA, as ohm's law show us: 0.6/10= 0.06 a . so lm 317 outputs only 60 ma while rest current is handled by 2n3055 or mje 3055 or tip 3055 or npn transistor.power dissipated by 10 ohm resistor = 0.6*0.6/10=0.036 w.-----------------i have few queries------------------1---------is current sharing between lm 317 and tip 3055 okay ---in future i will put 8 pcs more tip 3055 with small output equal balancing resistors as 0.22/5 w for equal sharing of power between transistors ?2--------------i want add constant current --in circuit---potentiometer value/watt( current adjustment should be sensitive i mean i can adjust from 0.5 to 0.78 a)----what extra modification circuit needed---a diagram would be very helpful if possible--------?3-----------weird problem----whenever i connect 5k or 10 k pot----it burns out--why-----using smallest wattage pot--i guess 1/2 w pot-----how exactly do i connect 3 legs of this kind of pot--a figure would be helpful-- ?--https://www.build-electronic-circuits.com/wp-content/uploads/2015/11/potentiometer.jpg----------------------thank you------------------

author: Seekonk
author_rank: Super Contributor
timestamp: November 26, 2017, 10:47:48 pm
content: But, not right. 220 ohm should go to capacitor.

author: danadak
author_rank: Super Contributor
timestamp: November 27, 2017, 12:26:06 am
content: Take a look at this -http://electronics-diy.com/1.2-36v-5adjustable-power-supply-with-lm317.phphttp://www.circuitsgallery.com/2013/07/high-current-adjustable-power-supply.htmlhttp://www.electronicshub.org/0-28v-6-8a-power-supply-circuit-using-lm317-2n3055/Regards, Dana.

author: rahulrahullll
author_rank: Contributor
timestamp: November 27, 2017, 04:52:56 pm
content: is there anybody else----------
LM1117 package questions - Page 1
Forum section: electronics / beginners

author: generic_username
author_rank: Regular Contributor
timestamp: January 28, 2016, 09:17:16 am
content: hello everyone,a noobish question:I want to use a LM1117 3v3 fixed linear regulatorlhttp://www.digikey.com/product-search/en?pv16=8250&FV=ffecc4f7&k=Lm1117&mnonly=0&newproducts=0&ColumnSort=0&page=1&quantity=0&ptm=0&fid=0&pageSize=25So it is stated here that it is TO220-3 Packagein the datasheet provided:http://www.ti.com/lit/ds/symlink/lm117.pdffhttp://www.ti.com/lit/ds/symlink/lm1117.pdfAll I can see is the NDE0003B (page 42)and the NDG0003F (page 43)these 2 packages looks really similar to a TO220 but the different names confuses me a littleThe NDG0003F appears to be surface mounted? or are the pads through hole but bend by 90°?this one would actually be the one I needed as I have to mountit to the metalplate on the PCB but what would be the right package to choose for the manufactor?Update to the question: the NDE0003B page 29 is the TO220 package just with a different name?Hope Someone can bring a little light to this matter.cheers.

author: sleemanj
author_rank: Super Contributor
timestamp: January 28, 2016, 10:44:47 am
content: YesSee page 24 the last 4 entries in the table, note "Package Type" is TO-220 and the drawing is "NDE" (for NDE0003B)NDE0003B is probably TI internal code for TO-220, or they just copied and pasted the page from some antique datasheet with some funky package name.

author: generic_username
author_rank: Regular Contributor
timestamp: January 28, 2016, 10:52:42 am
content: thank you I overlooked that
LM13700 vco not oscillating  - Page 1
Forum section: electronics / beginners

author: Unknown
author_rank: Unknown
timestamp: May 27, 2019, 01:31:20 pm
content: Hi everyone, I’m working on a vco that I built using a schematic from page the Texas Instruments datasheet for the lm13700. I’m using the triangle/square circuit found on page 19, and I can’t get it to oscillate at all. I I have everything on my breadboard connected exactly as in the schematic, except that I’m using 3 10k resistors in series for the input bias current on pin 16 instead of 1 30k. I have a 200pf ceramic disc capacitor, and the control voltage into pin 1 is 4 Vdc. I have my channel 1 oscilloscope probe hooked up to the square wave output , and my channel 2 probe hooked up to the triangle wave output. When I turn power on to the circuit, the trace stays flat on channel 1, and channel 3 gets pulled downwards. I will include a picture of the schematic. I’m pretty stumped here, and any ideas of suggestions would be greatly appreciated. Thanks, Ryan

author: JPortici
author_rank: Super Contributor
timestamp: May 27, 2019, 02:48:25 pm
content: the circuit should work without issues.Two ideas:- check the power supply, should work between +/-5 and +/-15. Some nodes are at GND and others are at -V!!- Maybe the darlington buffers are damaged. Besides being merely passable in specs, they are really fragile. You can try using an opamp voltage follower instead

author: Unknown
author_rank: Unknown
timestamp: May 27, 2019, 11:37:32 pm
content: Thanks! I have a few lm358’s laying around so I’ll try using one of those for the voltage followers. I certainly want a circuit that’s relatively robust since I plan on building an analog synthesizer using this vco design.
LM1875 Amplifier Board/ should I use common GND planes on audio boards? - Page 1
Forum section: electronics / beginners

author: dosensuppe
author_rank: Contributor
timestamp: September 03, 2025, 08:57:11 am
content: Hello. I am working on a simple board for the LM1875 Chip amp.I have quite a few design questions I would like to have resolved before having this printed at fab. I am reposting this here in case someone hasn't seen my post in the project section.https://www.eevblog.com/forum/projects/lm1875

author: ahsrabrifat
author_rank: Regular Contributor
timestamp: September 03, 2025, 03:11:18 pm
content: Yes, use a common ground plane. Partition and star-connect signal and power grounds. Do not let high-current speaker returns share copper with low-level input returns. Use a single star tie where the power return, signal ground, and amplifier ground meet. Place this star tie preferably at the power-supply entry, or at a single ground pour tie next to the LM1875. Avoid separate ground islands that are connected only by long skinny traces. If you have a poured ground plane, stitch it with vias around the amplifier. Place the star tie near the power capacitors or the bridge rectifier. Make sure the signal input ground returns do not run under the output traces.

author: dosensuppe
author_rank: Contributor
timestamp: September 05, 2025, 12:10:56 pm
content: there seems to be a lot of conflicting opinions regarding GND splits...https://www.eevblog.com/forum/projects/digitally-controlled-baxandall-tone-control-preamplifier/msg5956121/#msg5956121What I took away is that if one keeps enough distance between power and signal lines one should not run into trouble. Supposedly splitting supplies can also lead to EMI issues.
LM211 vs LM311? - Page 1
Forum section: electronics / beginners

author: aneevuser
author_rank: Frequent Contributor
timestamp: January 17, 2020, 10:54:40 am
content: Am I right in thinking that an LM211 is identical to an LM311 with the exception of some slightly different max voltages and apparently rather better electrical characteristics (e.g. input offset voltage/currents)? Or have I missed some fundamental difference when skimming the datasheets?The reason I ask is that the 211s seem to be a bit cheaper (through Farnell at least) in which case there seems to be little point in going for the 311s over the 211s, if they are more-or-less identical.

author: Gyro
author_rank: Super Contributor
timestamp: January 17, 2020, 10:58:55 am
content: Yes, just tighter spec, -40 - +85'C instead of 0 - 70'C Temp etc.P.S. It's the same coding for most 'traditional' NS parts. Eg. LM301= Commercial, LM201 = Industrial, LM101 = Military.

author: wraper
author_rank: Unknown
timestamp: January 17, 2020, 10:59:30 am
content: The same IC with testing/binning to tighter spec.

author: exe
author_rank: Unknown
timestamp: January 17, 2020, 12:56:57 pm
content: Quote from: aneevuser on January 17, 2020, 10:54:40 amIt's interesting that 2xx is cheaper than 3xx. It should be another way around. My guess is people don't bother with 2xx, and, because of low demand, they had to put price lower.I also won't be surprised if 3xx meets the spec of 2xx (due to progress in manufacturing process, unless they still use old equipment). But, of course, this is not guaranteed.

author: aneevuser
author_rank: Frequent Contributor
timestamp: January 17, 2020, 01:19:14 pm
content: Thanks all. Clueless noob will note the 1xx/2xx/3xx classification for later reference.As for prices, this is Farnell's DIP comparator offerings for the 211 and 311:https://uk.farnell.com/w/c/semiconductors-ics/amplifiers-comparators/comparators?no-of-comparators=1-comparator&comparator-case-style=dip&st=311

author: magic
author_rank: Super Contributor
timestamp: January 17, 2020, 01:26:47 pm
content: IME it's the obscure parts which are more expensive at distributors. Quite possibly the 211 grade is no harder to produce with modern technology than 311 so whichever moves in larger quantities (see stock levels) gets cheaper because otherwise the base price is the same.

author: exe
author_rank: Unknown
timestamp: January 17, 2020, 01:47:45 pm
content: Quote from: aneevuser on January 17, 2020, 01:19:14 pmWait, one part is LMxxx, and another one is LPxxx. Those are different parts, imho.

author: aneevuser
author_rank: Frequent Contributor
timestamp: January 17, 2020, 02:08:44 pm
content: Quote from: exe on January 17, 2020, 01:47:45 pmThe first is an LM211P at £0.373 in small quantities, the third is an LM311P at £0.435 in small quantities, at least on the page that I'm seeing - maybe you're getting something different for some reason (cookie maybe?)