hybridfree/eevblog-posts huggingface dataset:
[Q] INA226 and low-side current sensing - Page 1
Forum section: electronics / beginners

author: AlxDroidDev
author_rank: Frequent Contributor
timestamp: January 29, 2016, 04:45:27 pm
content: For my electronic load project, I decided to use aTexas' INA226. If I went with the INA219 (high-side only), I'd have to use 2 shunt resistors: one, high-side, for the INA219, and another one, low side, for the opamp's feedback. Plus the INA219 is limited to 26V, and I'd like to go up to 30V.1) Using the INA226, I can share the same shunt resistor for the INA226 and the opamp feedback, correct?2) If I understood the INA226 datasheet correctly, when used on the low-side, it must be the last device in the current loop before ground. Is that correct? Is so, it means I cannot use this project as a constant current source for other devices that I'd connect after the load, such as a battery I wish to charge or a LED I wish to test.3) Does the VBUS pin always have to be connected to the Vin pin? Can I connect the VBUS pin to the high side of the load, before the FET?thank you!

author: Kleinstein
author_rank: Super Contributor
timestamp: January 29, 2016, 05:31:24 pm
content: The INA226 can measure two voltages, a smaller one between the two inputs for the shunt and a second one between GND and VBus. Its is up to you to decide where to have the inputs. The main thing is to have less than 36 V at any input relative to GND. So the shut can be high side or low side or somewhere in the middle if you like and have two loads in series. So if a 30 V outout is planed the raw voltage before regulation might be to high under wirst case conditions.

author: AlxDroidDev
author_rank: Frequent Contributor
timestamp: February 02, 2016, 09:57:51 pm
content: Quote from: Kleinstein on January 29, 2016, 05:31:24 pmVielen Dank!
[Q] What are these parts? - Page 1
Forum section: electronics / beginners

author: fusionimage
author_rank: Contributor
timestamp: April 30, 2015, 04:09:18 pm
content: hi! this is an old garage door opener from 1991.i would like to know, of these parts are inductivities and what colorcode they use?they have 5-6 pins

author: nitro2k01
author_rank: Frequent Contributor
timestamp: April 30, 2015, 04:15:34 pm
content: Those look like trimmers (could be resistive, capacitive or inductive) and the dabs of paint probably just mean that the trimmer in question was calibrated.

author: daqq
author_rank: Super Contributor
timestamp: April 30, 2015, 04:18:09 pm
content: Shielded tunable coils. Some of them might have a capacitor or some misc extra parts inside, but most of it is the inductor. You tune it by adjusting the height position of the ferrite core.

author: TimFox
author_rank: Super Contributor
timestamp: April 30, 2015, 04:18:25 pm
content: Those are adjustable inductors: slug-tuned coils. They presumably tune the opener to the RF operating frequency.

author: w2aew
author_rank: Super Contributor
timestamp: April 30, 2015, 04:20:48 pm
content: Quote from: fusionimage on April 30, 2015, 04:09:18 pmThey're certainly either adjustable inductors or IF transformers. Unless there are some part number markings printed or stamped into the metal housings, you'd have to remove them to measure them. You could use a technique like this video to measure them, whether they are inductors or tuned IF coils or transformers:

author: fusionimage
author_rank: Contributor
timestamp: April 30, 2015, 04:27:57 pm
content: thanks a lot!

author: mathias
author_rank: Regular Contributor
timestamp: April 30, 2015, 04:41:19 pm
content: Tunable inductor is indeed most likely, but there also exist helical filters of this shape and size.

author: SeanB
author_rank: Super Contributor
timestamp: April 30, 2015, 05:08:41 pm
content: With the age of that board that is not likely. Most likely the one on the bottom left is a 455kHz oscillator to do FM modulation on the crystal. the top 2 are to select harmonics of the crystal before they go to the final amplifier and the output tuned circuit, the black coil on the left with the thick silvered wire.

author: fusionimage
author_rank: Contributor
timestamp: May 15, 2015, 09:33:33 am
content: Ok, I'll try to reverse engineer itfyi: the transmission frequency is ~40MHz
[QUESTION]Little programming question - Page 1
Forum section: electronics / beginners

author: anker_by
author_rank: Contributor
timestamp: September 07, 2017, 06:26:25 pm
content: Hello everyone, I want to know if Pythong works across with micro processor, electronics... etc... sorry for noob question...Regards,- Anker_by

author: daybyter
author_rank: Frequent Contributor
timestamp: September 07, 2017, 06:50:43 pm
content: Checkhttps://micropython.org/

author: Brumby
author_rank: Unknown
timestamp: September 08, 2017, 04:18:54 am
content: Quote from: anker_by on September 07, 2017, 06:26:25 pmNo need to apologise - thisisthe Beginners section.
[Question/Advice] Adaptive/Intelligent Lighting System - Planning and Parts - Page 1
Forum section: electronics / beginners

author: superheromario
author_rank: Newbie
timestamp: January 16, 2021, 04:41:52 pm
content: Hi guys,I think this is the first time I post here and I am not sure if it's the appropriate place to do so, so please guide me out if it isn't. Thank you.I sort of have some spare time while waiting for my job application, and so I'm thinking of something to fill in my gap time cause I don't play games anymore.I want to have a lighting control system in my room (which is about 10-12 metres square).I am thinking of using the Pi 4 as the controlling board, with a number of sensors around my place. At first I thought of some proximity sensors, then I thought of IR, but then I had this problem where I thought that IR could easily be spoiled by other source of heat in the room. So for the time being I am not even sure which sort of sensor I should be using. Would love to hear form your advice.Next thing I am thinking of using batteries with a simple and small board, for example what comes to my mind is a board from STM32, like the one I used in my school, that can communicate using Bluetooth for example. But I don't know if there's any other better option. Because if not using batteries then I need to route all the wires in my room, which is what I want to avoid.About the idea, maybe you will ask why not just use an IR device available on the market, which if I look for, I could easily find one for about less than 40 euros. But there's problem with those things, they only detect movement, while in my plan, I want the light to be on even when I am idle. I have sort of an idea about how things work in my mind, though I haven't sketched anything. I want the room to be lit as long as I am awake, working (I will define exactly what that means later), and when I am about to sleep (for example when I lie down), the lights turn off.About the lights, at first I thought of using simple transistors to control the electricity but there's couple of problems which I am not very confident on, I am not very good at Physics in the past, so I am not sure if it's okay to let AC flow through the transistor. That's for starters, and I am quite scared of letting the wires running and that there's a chance there's electricity leak somewhere (but I'll work that part out). I have a second thought where I might end up using LED's (or LED strips) for this, but I'm wondering if a bunch of LED's could provide the same amoung of illuminations as the light bulbs.Well that should be all for now and by all means, thank you for reading the messy post. Wish you all a gread day/night ahead.Love from Vitry.
[Review Request] micro SD card schematic - Page 1
Forum section: electronics / beginners

author: kuelezav
author_rank: Newbie
timestamp: December 15, 2024, 10:04:43 pm
content: Hello everyone. I was hoping to get some feedback on my schematic for an SD card socket. Will this design work? My aim is record sensor data (accelerometer, temperature, pressure, etc.) and store onto an sd card using SPI communication with an ESP32. Would this design work? Is there anything I can do to improve it? Any help would be greatly appreciated.Thanks.https://1drv.ms/i/s!Asdy5Rhffb67tCDIX1rHm1HR9td0?e=N3WkeDhttps://1drv.ms/i/s!Asdy5Rhffb67tB8gssjrHJdLJW0W?e=35cFmd

author: Benta
author_rank: Super Contributor
timestamp: December 15, 2024, 10:45:55 pm
content: Why are there two schematics?Just place the whole thing on one sheet and draw the wires.

author: ataradov
author_rank: Super Contributor
timestamp: December 15, 2024, 11:03:19 pm
content: Your GPIO12 and CLK of the card is connected directly to VCC.

author: kuelezav
author_rank: Newbie
timestamp: December 15, 2024, 11:08:36 pm
content: https://1drv.ms/i/s!Asdy5Rhffb67tCEufFxDQUo24-m3?e=ljAF20How about this one? For clock, is it better to have it connected only to the GPIO on the ESP32 or should I add a pull-up resistor to CLK?

author: kuelezav
author_rank: Newbie
timestamp: December 15, 2024, 11:15:45 pm
content: They're both on the same schematic. I just screenshot these two.

author: ataradov
author_rank: Super Contributor
timestamp: December 15, 2024, 11:21:13 pm
content: Direct connection should be fine. Or place a resistor and not populate it if it causes issues.A better idea is to find a working design and copy it.

author: Benta
author_rank: Super Contributor
timestamp: December 15, 2024, 11:25:20 pm
content: Quote from: kuelezav on December 15, 2024, 11:15:45 pmSo what's your expectation? If it's screenshots from a half-finished design, it's futile.Do the homework and THEN ask for a review.

author: kuelezav
author_rank: Newbie
timestamp: December 15, 2024, 11:32:28 pm
content: https://1drv.ms/i/s!Asdy5Rhffb67tCJRn_Itcs7zvmNM?e=bZr8OQHow about this? Is this what you were referring to?

author: Benta
author_rank: Super Contributor
timestamp: December 15, 2024, 11:36:40 pm
content: Dunno. Needs a login.

author: kuelezav
author_rank: Newbie
timestamp: December 15, 2024, 11:41:47 pm
content: Sorry about that. Are you able to see this one?

author: kuelezav
author_rank: Newbie
timestamp: December 15, 2024, 11:50:48 pm
content: Apologies. The link may not be accessible. Are you able to see the attached image?
RF basics - Page 1
Forum section: electronics / beginners

author: papamoscas
author_rank: Newbie
timestamp: July 17, 2018, 10:42:06 am
content: Hi,I'm a beginner in the world of the PCB's and of RF. I need your help and your knowledge.I want to make a PCB with the Quectel MC60E with the two SMA connectors, one for GSM signal, other for the GPS/GLONASS. For the BLE I want to put one antenna on the board like A5839 Antenova (http://www.antenova-m2m.com/wp-content/uploads/2016/01/Rufa-A5837-A5887-PS-1-2.pdf).I already did my research but I'm a bit confused, I think I only need to take care of the 50 Ohm pad from the MC60E to SMA connector.My questions are :- I only need to take care of the impedance matching? What is the best procedure to do that?-What are the most important things to have a PCB without EMI problems? The PCB will have more components like sensors for example...Thanks in advance
[RFC on YT Video] "How VRMs work" - DaveCAD, MOSFETs, PWM, Phases, …and stuff - Page 1
Forum section: electronics / beginners

author: faekjarz
author_rank: Regular Contributor
timestamp: October 29, 2016, 01:21:58 am
content: Hey there!I've found this video on YT ?? and i like it. Since, according to Louis Rossmann (https://www.youtube.com/user/rossmanngroup), this here forum sometimes tends to be overly critical, i'd like to request some of that over-criticallity.The dude didn't elaborate on the (purpose of the) caps …those are for smoothing the ripple of the phases, right?

author: T3sl4co1l
author_rank: Super Contributor
timestamp: October 29, 2016, 03:46:55 am
content: A half an hour? Meh...If you mean bypass caps, then yes, smoothing input and output voltages.Tim
[Rigol] Oscilloscope ground clip leads - Page 1
Forum section: electronics / beginners

author: int2str
author_rank: Regular Contributor
timestamp: April 06, 2015, 05:51:13 am
content: Just got a Rigol DS1054Z. I really don't like the alligator clips on the ground leads.Does anybody make leads with spring loaded hooks?Also, are the ground clips Rigol specific or do other manufacturers use the same diameter spade attachment point?

author: Smokey
author_rank: Super Contributor
timestamp: April 06, 2015, 06:19:51 am
content: Funny. I said the same thing.I had a set of 4 cheap Chinese 100MHz probes I got for like 15 bucks off ebay that I had already replaced the alligator clips for EZHooks. I just desoldered the alligator clips and used some good Pomona EZhooks. Those probes use the same type of ground wire as the new DS1054Z, so I just swapped them out. If I want alligator clips for something, I can just swap them back.http://www.ebay.com/itm/Two-P6100-DC-100MHZ-Oscilloscope-Scope-Clip-Probe-100MHz-For-Tektronix-HP-SY-/331378782364?pt=LH_DefaultDomain_0&hash=item4d27b6f09c
[Schematic Review Request] FPGA Power Circuit - Page 1
Forum section: electronics / beginners

author: HasanSyr
author_rank: Contributor
timestamp: March 12, 2025, 06:39:55 pm
content: FPGA Power Circuit for my development board built around/for a SOM.

author: jwet
author_rank: Frequent Contributor
timestamp: March 13, 2025, 02:57:27 pm
content: The one glaring problem that I see is that you can't buck a 5v nominal signal from USB Vbus to 5v- there is no headroom. Though the 62130 can run at 100% duty cycle, you'll still have IR losses through the internal FET and the inductor resistance. The HS FET has a resistance of 90 mohm so with a 2 amp load, you drop 180 mV plus the inductor IR drop. USB rails are often at or below 5v when loaded. Can you use Vbus without a buck for 5v and use the buck only on 3.3V. All the curves in the data sheet show a volt or more of headroom.As far as the rest, it look ok. I assume you used Webbench. Also follow the layout guidelines- these are very high frequency switchers and need a tight layout. Section 11 in the DS is very good for layout details.

author: HasanSyr
author_rank: Contributor
timestamp: March 13, 2025, 05:36:09 pm
content: Quote from: jwet on March 13, 2025, 02:57:27 pmSomeone has mentioned the same point and recommended using Buck/Boost. Im thinking of using TPS63020DSJR, if VBUS is below/above 5V it can adjust I think.
[Search] Datasheet UAA3000 - Page 1
Forum section: electronics / beginners

author: PinheadBE
author_rank: Regular Contributor
timestamp: July 16, 2019, 08:08:08 am
content: That IC is a timer made by Valvo that can be directly used on mains power and used in an application circuit that has been around for quite some time now.Seehttp://electroniq.net/other-projects/uaa3000-timing-circuit-electronic-project.htmlI am looking for the datasheet for that little beastGoogle and usual datasheets websites return nothing.I have some of those IC's laying around and would like to see what I could use them for.So, if you have a datasheet for UAA3000, feel free to share.Thanks
[Solved] Unity Gain Differential Amplifier not working as expected - Page 1
Forum section: electronics / beginners

author: king.oslo
author_rank: Frequent Contributor
timestamp: January 13, 2012, 12:20:07 am
content: Hello there,I made an Unity Gain Differential Amplifier circuit. This tutorial told me that Vout = V2-V1:http://www.electronics-tutorials.ws/opamp/opamp_5.htmlMy exact schematic is attached. R1-R4 are 22R3The problem is that Vout != V2-V1.I built it up using a Microchip MCP6041 on a bread board. This is what I found:Case 1:V2: =1.475VV1: =2.835VExpected Vout = -1.36VVout = 1.936VExpected Vout != Vout----------------------------------------Case 2:V2: = 0.982VV1: = 2.829VExpected Vout = -1.847Vout = 1.930Expected Vout != VoutThis is the datasheet for the opamp:http://ww1.microchip.com/downloads/en/DeviceDoc/21669c.pdfWhat have I missed?Thanks for your time.Kind regards,Marius

author: IanB
author_rank: Super Contributor
timestamp: January 13, 2012, 12:27:00 am
content: Are you supplying the op amp with a dual rail supply? You have not said how you are powering it.You cannot expect to get a negative voltage out of an op amp unless you have a negative supply voltage fed into it.

author: king.oslo
author_rank: Frequent Contributor
timestamp: January 13, 2012, 12:35:30 am
content: Quote from: IanB on January 13, 2012, 12:27:00 amOpamp is powered by 5VDC to gnd. I think you just pointed out the problem.

author: slateraptor
author_rank: Frequent Contributor
timestamp: January 13, 2012, 12:36:19 am
content: Quote from: king.oslo on January 13, 2012, 12:20:07 amHere's your problem, viz. your lower rail is tied to ground, thus cannot produce negative voltage.

author: king.oslo
author_rank: Frequent Contributor
timestamp: January 13, 2012, 12:39:23 am
content: That's great.It says my opamp can only do 1.4V to 6.0.Does that mean that I power it like this: VDD = 6V, VSS = 0V. Then pull inverting input to 3VDC, and then measure Vout between Vout and 3VDC?1. That should work, right?2. Is this the traditional way to do it?Thanks.M

author: slateraptor
author_rank: Frequent Contributor
timestamp: January 13, 2012, 01:11:21 am
content: Instead of tying R4 to ground, tie it to Vcc/2. Then measure your output with respect to Vcc/2. This is standard single-supply practice.EDIT: If you analyze the circuit assuming the op amp is ideal, you can easily see why this will work. I encourage you to give it a shot.

author: king.oslo
author_rank: Frequent Contributor
timestamp: January 13, 2012, 02:24:05 am
content: Thanks.Since I wasn't doing this, I was measuring Vout with respect to gnd, and tying R4 to gnd as well. What values was I actually measuring?Thank you for you time. Both of you.Kind regards,Marius

author: slateraptor
author_rank: Frequent Contributor
timestamp: January 13, 2012, 02:53:04 am
content: Quote from: king.oslo on January 13, 2012, 02:24:05 amThe op amp's output wasn't within its normal operating region; you were effectively measuring junk.

author: king.oslo
author_rank: Frequent Contributor
timestamp: January 13, 2012, 08:40:02 am
content: Quote from: slateraptor on January 13, 2012, 02:53:04 amOk, thanks!M
[Solved] What's the Q of this circuit? - Page 1
Forum section: electronics / beginners

author: SoftwareSamurai
author_rank: Regular Contributor
timestamp: November 10, 2011, 03:49:25 pm
content: While tying to learn more about bandpass filters, I stumbled acrossthis circuit(see pic). Does anyone know how to calculate the Q of this filter?I know that the addition of the Rload changes the Q, but I'm not sure how to factor both R1 and Rload into the math.

author: Rufus
author_rank: Super Contributor
timestamp: November 10, 2011, 04:11:46 pm
content: V1 has zero impedance. If you replace V1 with a line it becomes obvious that R1 and Rload are in parallel.

author: jimmc
author_rank: Frequent Contributor
timestamp: November 10, 2011, 07:44:04 pm
content: The resonant frequency of L1 & C1 is 159.15Hz at this frequency the reactance (X) of either is 100 Ohm.As Rufus has said RSand RLappear in parallel so their combined resistance (R) is 333.3 Ohm.Calculate Q as R/X = 3.333Jim

author: SoftwareSamurai
author_rank: Regular Contributor
timestamp: November 10, 2011, 09:15:23 pm
content: Thanks Rufus. I hadn't thought of V1 with zero impedance. I think that's what I was missing.Thanks Jim. I thought that Q = R/X, but I wasn't calculating R correctly which made me think that I had the wrong formula for Q.
[STM32] Why a “0” in the output data register activates the N-MOS? - Page 1
Forum section: electronics / beginners

author: unscripted
author_rank: Contributor
timestamp: August 24, 2022, 12:04:49 am
content: Really a beginner question.. but I thought a N-MOS like a N-Channel MOSFET was activated with "1" logic but while using a STM32 GPIO as open drain output I realized the N-MOS is activated with a "0". I would appreciate any quick enlightenment or suggested documentation to read more about N-MOS and P-MOS. Thanks.

author: fourfathom
author_rank: Super Contributor
timestamp: August 24, 2022, 12:52:22 am
content: You are correct about turning on an isolated NMOS transistor, but in this case the magic happens in that "Output Control" box. There the "0" is inverted (and potentially disabled in order to force both the NMOS and PMOS transistors off when you want to use that pin as an input). The NMOS/PMOS transistors invert the polarity once again and so an logic "0" becomes 0V at the pin.

author: Siwastaja
author_rank: Super Contributor
timestamp: August 24, 2022, 11:58:54 am
content: It's an arbitrary choice. 0 corresponds to output pulled down to GND, 1 corresponds to output pulled high to Vcc. In open drain mode, latter means, pulled high by external resistor. The polarity of voltages is of course the same in push-pull and open-drain modes.One could have chosen opposite logic, so that 0 = higher voltage and 1 = lower voltage, but IMHO, that would be pretty weird. Even more weird would be to use different notations in push-pull vs. open drain mode.
[TINA-TI or LTspice] Trouble with LM5002 simulation - Page 1
Forum section: electronics / beginners

author: bodzio_stawski
author_rank: Regular Contributor
timestamp: January 23, 2024, 10:49:18 am
content: Hello,I wanted to recreate the LM5002 circuit in the TINA-TI program which seemed to me to fit the Texas chip like a glove.Unfortunately, the effects of this program quickly took their toll on me, and the circuit simply does not work properly, when it comes to output voltage.In fact, I could say that the output voltage is close to the set input voltage instead of being increased. A factor that may be crucial in this case is that I had to import the LM5002 chip into the TINA-TI program, which I did using the Tools-New Macro Wizard function.I downloaded this model of LM5002 from this manufacturer's link:Link to the LM5002 modelhttps://www.ti.com/product/LM5002?utm_source=google&utm_medium=cpc&utm_campaign=app-null-null-GPN_EN-cpc-pf-google-wwe&utm_content=LM5002&ds_k=LM5002&DCM=yes&gad_source=1&gclid=CjwKCAiAkp6tBhB5EiwANTCx1I02KymlWGVlOnDBXDaCyRaUBd2jIqiBK5bZqMnmFRwDUyP8UJMsixoCs_0QAvD_BwE&gclsrc=aw.dsIs it possible that I am making some mistake in running the circuit here?Link to my file: LM5002.TSChttps://easyupload.io/5u7xaw

author: bodzio_stawski
author_rank: Regular Contributor
timestamp: January 25, 2024, 07:32:21 am
content: Alternatively, do any of you have an LM5002 model that can run on LTSpice?I tried to use the same one (in .lib format) from the TI website, but it does not work the same as in TINA TI. When I prepared an alternative circuit with LT1371 in a similar configuration as boost converter, it worked (although it is, of course, an Analog IC, saved with the.subextension).
[Tools] Battery pack calculator. - Page 1
Forum section: electronics / beginners

author: jekhatulan
author_rank: Newbie
timestamp: November 12, 2017, 10:56:46 am
content: Hi!I want to share this simple tool that I recently created for Beginners like me. It's a Battery pack calculator.It calculates the voltage, capacity and show your battery configuration ( ex. 4s 10p ) based on how many cell you have and how many S (serial connection you want).There's also a custom Calculator there if you want to design based on how much voltage, and parallel group you want it will give you the same output like the first one.If I have mistakes on my calculator just leave your comments or send me PM and If there's is a computations that I need to include and consider, just tell me.Thank you!
[TV] Capacitor issue? - Page 1
Forum section: electronics / beginners

author: rthorntn
author_rank: Frequent Contributor
timestamp: August 28, 2021, 09:33:42 am
content: Hi,My 7.5yo LG 55EA9800 TV is playing up.Basically (as of yesterday) when I first turn it on from standby I get horizontal streaks and trails of pixels, flickering and blanking. After about 30 minutes it goes away.I think I remember reading that failing electrolytic capacitors have this "once it warms up the problem goes away", is that correct?I mean if its a simple repair then that would be great. I'd rather keep this set for another 2-3 years, it cost an absolute bloody fortune back in 2014.CheersRichard

author: Psi
author_rank: Super Contributor
timestamp: August 28, 2021, 09:50:01 am
content: Hard to say, but yes, it might be bad capacitors.Might be something else too though.If it is just bad caps then yes, it is a simple repair for anyone who knows how to use a soldering iron and knows enough about capacitors to buy the correct replacement caps.You can also buy entire new boards for like US$60-100 on aliexpress. But the seller ratings look a bit low for me to want to take the risk on them.
[Wanted] function generator and laboratory power supply - Page 1
Forum section: electronics / beginners

author: fxr
author_rank: Contributor
timestamp: December 10, 2019, 10:14:14 pm
content: Hello everyone!I want to ask experienced people for advice about equipping for home lab.The main specialization of my projects is hardware design of digital audio devices.I need advice for acquiring a function generator and laboratory power supply.For this money I can buy Rigol DG4102 and Rigol DP832.For my opinion, this best price-quality ratio.How you thinks about my choice?Any advice and opinions...

author: rapsforlife
author_rank: Newbie
timestamp: December 10, 2019, 11:08:33 pm
content: Try posting in the Test Equipment subforum
[What could possibly go wrong?] Transplanting a Lithium cell protection cirquit - Page 1
Forum section: electronics / beginners

author: faekjarz
author_rank: Regular Contributor
timestamp: October 02, 2017, 07:04:55 pm
content: Hey there, Enginerds!What could possibly go wrong?...when i transplant a (this) Lithum cell protection board onto a new, not bloated, cell?I'm asking for my alter ego, who bought a fairly grunty octa-core chinaphone, without double-checking availability of replacement batteries. My alter ego really wants to make that turd great again.Please throw your wisdom, explanations and sources at these questions:Of course, i'd choose a new donor cell with the same specs as the original; Good enough?What spec deviations could be considered, "sufficiently same" (as in safe)?What could possibly go wrong? (Do you have experiences, success or fail stories to share?)What does "Execution Standard" mean / what is being standardised?Are execution standards documented somewhere? (Where? Links?)

author: Bicurico
author_rank: Super Contributor
timestamp: October 02, 2017, 08:24:44 pm
content: By no means am I an expert, but to the question "what could go wrong" I do have an answer:In worst case, the new cells will catch fire and/or explode. The fire will quickly reach such high temperatures, that you won't be able to extinguish the fire using normal processes like water.I am not sure how likely this is going to happen, but since the damage can be huge, even a small risk may void what you are planing to do.Regards,Vitor

author: KL27x
author_rank: Super Contributor
timestamp: October 02, 2017, 10:04:49 pm
content: The max charge/discharge rate (if it's even approached by the charging circuitry) should be fairly similar. This has fairly strong correlation to mAh capacity in practice (but in theory, not really. There's are high charge/discharge variations made for RC helicopters and whatnot).So in theory it might be possible you cause battery to pop. But IMO, the two things I'd worry most about are1. There a stupid chip on the circuit for protection to prevent you from reusing it. Once power is disconnected, it is dead, barring access to some factory reset protocol.2. You have zapped one of the FETS with ESD while transferring it due to careless handling.I wouldn't worry about it at all; I just wouldn't leave the phone charging unattended for the first score of cycles and observe that the battery is not overheating/bulging. Also, make sure you do your initial test runs with a HI output charger, with full 2+A output, to cover all your bases.
*** Hooking up a single capacitor So COnFusEd *** - Page 1
Forum section: electronics / beginners

author: jfiliaul
author_rank: Newbie
timestamp: July 06, 2011, 12:40:17 am
content: Ok, this maybe a very silly question but I cant find the answer. What is the difference between hooking up a capacitor inline (in series) with the positive line in a circuit and hooking it up in parallel (one side on negative line and one on positive)? It sounds like a real dumb question to me but I have seen it done both ways and Im sure there are reasons why to do it each way but can anyone help shed the light on this for me?Example: Here is an RC circuitNegative side --------------------------------\| /| \cap resistor| /Positive side --------------------------------\VSNegative side --------------------------------\/\resistor/Positive side ----------|---cap----|---------\THANKS FOR THE HELP !!!

author: Ian
author_rank: Contributor
timestamp: July 06, 2011, 01:07:42 am
content: hithe first one looks correct to me. that is the way they are normally hooked up

author: w2aew
author_rank: Super Contributor
timestamp: July 06, 2011, 02:56:59 am
content: It depends entirely on the application.The parallel combination can be considered a low-pass filter. It's a typical configuration for filtering a power supply for example. It allows DC to flow through the resistor, and shunts AC away from the resistor. The higher the frequency, the more that is shunted.The series combination can be considered a high-pass filter. It blocks DC from passing through the resistor. Thus, the impedance of the circuit is very high (infinite) at DC, and drops as the frequency increases.The answer is - both are correct. Each of these configurations are used for different purposes.

author: Tony R
author_rank: Regular Contributor
timestamp: July 08, 2011, 04:50:55 am
content: Look at how they will act in DC conditions... if your application is DC...in parallel the cap will act as a open circuit (no current will go though it) so you basically just have a resistor.in series, the cap will still act as an open circuit, so what happens with the current?for AC condtions we can kind of think the same way, what is a DC condition, essentially a very slow AC signal (where the period extends to infinity.) so with them in parallel, the current will tend to go though the resistor, in high frequencys, they will tend to go though the cap (acting as a short)
0-10v Variable Output Power Supply - Page 1
Forum section: electronics / beginners

author: Arzeo
author_rank: Newbie
timestamp: March 12, 2020, 09:35:21 am
content: I was wondering what would be the most simple way to get a 0-10v variable output power supply. I would be using this for a dimmer switch for this LED driverhttps://hubbellcdn.com/specsheet/LED-75W.pdfThere are so many light switches with a 0-10v dimmer built into them that are decently sized, it just seems almost ridiculous I can't find some simple plug with a potentiometer on it with 2 output wires. I have seen these little lm317 adjustable voltage regulators, but they seem to need a maximum window of ~3 volts above what your max output should be. I would want something I can just hook up to a 12v dc power adapter, or something more simple at a reasonable price.

author: Zero999
author_rank: Super Contributor
timestamp: March 12, 2020, 09:46:21 am
content: Why create a new thread? It's much easier if you keep everything related to a single thread.https://www.eevblog.com/forum/beginners/led-driver-0-10v-dimming/msg2957162/#msg2957162

author: Arzeo
author_rank: Newbie
timestamp: March 12, 2020, 09:54:16 am
content: In my previous experiences with forums, it felt like older topics would end up getting lost. This new thread gets right to the point so that new people don't have to go through the other thread to get to the most recent question since it isn't too related. I guess I should have tried asking the other thread before creating this one though.

author: Zero999
author_rank: Super Contributor
timestamp: March 12, 2020, 10:01:58 am
content: Quote from: Arzeo on March 12, 2020, 09:54:16 amThe information in the other thread is relevant to the question. Bump the thread, with more information, if you've not got the answer you were looking for. Creating a new one will not help as people will quite likely suggest things which are completely irrelevant.

author: Arzeo
author_rank: Newbie
timestamp: March 12, 2020, 10:08:55 am
content: So are you suggesting I abandon this thread and bump my old one?

author: Zero999
author_rank: Super Contributor
timestamp: March 12, 2020, 10:23:12 am
content: Quote from: Arzeo on March 12, 2020, 10:08:55 amYes, please do that, so everyone can have all the background information. I have an idea of how this can be done, but it's not an off the shelf solution. I'll post it in the other thread.

author: Simon
author_rank: Unknown
timestamp: March 12, 2020, 11:05:37 am
content: https://www.eevblog.com/forum/beginners/led-driver-0-10v-dimming/
0.1" pitch PCB header options - Page 1
Forum section: electronics / beginners

author: icon
author_rank: Regular Contributor
timestamp: March 08, 2015, 01:12:37 pm
content: HiI'm putting together a simple RIAA phono widget plus preamp from PCBs supplied by Rod Elliott. Between the power supply board, the phono thing and the preamp, there's quite a few 2, 3 and 5 hole 0.1" pitch connectors. I had thought of using screw connectors, but it'll be a tight squeeze, and I'm struggling to find a 5 hole one. Other thoughts are Molex headers and plugs or solder directly to the board (which could end up a proper cat's cradle).Molex connectors for mV signals? Any thoughts about that or otherwise?ThanksJohn

author: cosmicray
author_rank: Frequent Contributor
timestamp: March 08, 2015, 02:26:12 pm
content: Even if you decide to use Molex type plugs (of which there are an extensive variety) be aware that the same style can be had in multiple contact finishes (tin, various thicknesses of gold, etc). Some of those are rather difficult to locate, so you may way to consider contact resistance in the selection.

author: PeterFW
author_rank: Frequent Contributor
timestamp: March 08, 2015, 03:37:37 pm
content: Quote from: icon on March 08, 2015, 01:12:37 pmI have seen so many of these connector over the years in all sort of audio related gear carrying everything from mic level to power:http://www.zeenic.com/c64psu/T07.jpgWith contact surfaces from ranging from gold, silver, tin to various types i could not identify with certainty.I have seen standard ribbon cable with your house hold crim press fit connector and so much more.Yamaha, Allen&Heath, Denon, Pioneer, high end, low end...What i am trying to say is, get a next best decent cable with a connector and youre good to go. If you solder cabled directly onto a board, only solder one side and use a connector on the other.That is way, way more service friendly

author: icon
author_rank: Regular Contributor
timestamp: March 08, 2015, 09:28:54 pm
content: OK, thanks. I think I'll go with service-ability and ease of assembly - Molex (or equivalent).John
0.1uF ESR ? - Page 1
Forum section: electronics / beginners

author: Flump
author_rank: Frequent Contributor
timestamp: July 27, 2014, 03:00:47 am
content: I have a 0.1uF electrolytic cap whichmy tester measures as 107nFbut it cant get a ESR reading from the cap.Is this normal on caps this small ?

author: c4757p
author_rank: Super Contributor
timestamp: July 27, 2014, 03:02:44 am
content: Very low-value electrolytics tend to have very high ESR. It's possible that it's overrange.

author: Flump
author_rank: Frequent Contributor
timestamp: July 27, 2014, 03:21:59 am
content: thanks very much

author: PedroDaGr8
author_rank: Super Contributor
timestamp: July 27, 2014, 03:24:48 am
content: Quote from: Flump on July 27, 2014, 03:21:59 amI have a 0.1uF that I read an ESR of around 160. I think tan delta is a better indicator of health for these size caps (plus its in the datasheet)

author: Flump
author_rank: Frequent Contributor
timestamp: July 27, 2014, 09:22:52 am
content: never heard of tan delta so will do some research on itthanks Pedro

author: SeanB
author_rank: Super Contributor
timestamp: July 27, 2014, 09:27:20 am
content: Tan delta is basically how lossy it is. Even on electrolytics it gives a good idea of the health of a capacitor. The smaller the number the closer it is to an ideal capacitor.

author: w2aew
author_rank: Super Contributor
timestamp: July 27, 2014, 02:42:59 pm
content: Quote from: Flump on July 27, 2014, 03:00:47 amThat's a pretty small value cap to measure ESR on. Many ESR meters use something on the order of 100kHz as a test frequency. This cap will have 16 ohms of capacitive reactance at that frequency, which many ESR meter designs will incorrectly interpret as ESR.

author: AQUAMAN
author_rank: Regular Contributor
timestamp: July 28, 2014, 12:37:14 pm
content: U need to either buy a proper LCR meterOr u need a pulse generator and u can build a peak detector circuit to measure the peak current into the capacitor, from this u should be able to tell its ESR in some level roughlyI have built many circuits that approximately measure the ESR of gate capacitances in IGBTs or MOSFETs which are in the range of 50-100nF. They can be built very cheaply and easily.What I do is I measure the peak current flowing through the charging resistor.For my applications I only measure the CHANGE in the ESR during operation (and I measure this change in 1mOhm/C sensitivity), so actually I have no idea what the absolute value of it is and it does not matter to me either. But in theory you could probably work it out, even if I dont bother to do this.Using a pulsed ESR detection will never give u the true ESR as the peak current/instant voltage is dependent on the capacitor size, the inductance and also the resistance (search Peak Inflow Current into capacitors)

author: Flump
author_rank: Frequent Contributor
timestamp: July 29, 2014, 06:19:33 am
content: Thanks AlanAquaman how will a LCR Meter helm me measure ESR ?

author: AQUAMAN
author_rank: Regular Contributor
timestamp: July 29, 2014, 09:10:03 am
content: Because thats what it measures?U can tell them to measure Cs-RsRseries is the ESR of the cap right?
0-2v ADC - Page 1
Forum section: electronics / beginners

author: KNSSoftware
author_rank: Regular Contributor
timestamp: November 13, 2017, 10:38:58 pm
content: HiGot a nice little first project coming up, and I am going to need an ADC for a 0-2v input, with at least 14bit resolution (0->10,000). I have an ADS1115, but unless I am looking at the datasheet wrong, the min is 2v just to start, which is a deal breaker. If so, any recommendations? I am aiming for the same sort of price point? Can I even do any sort of simple (and i mean simple; this is my first outing) amplification/dc offset, and use what I have got?ThanksJohn

author: danadak
author_rank: Super Contributor
timestamp: November 13, 2017, 11:16:59 pm
content: The ADC supply min is 2V, but characterized at 3.3V. At 3.3V Vdd itsinput range is 2.048 V full scale, differential (+/- 2.048V).Is this what you are asking about ?Regards, Dana.

author: KNSSoftware
author_rank: Regular Contributor
timestamp: November 13, 2017, 11:30:09 pm
content: DanadakTo be honest, I am learning as I am going, so please bear with me. Is that part of the gain feature? Basically I can supply any VCC needed 3.3/5v, no prob, but my analogue output from the sensor will be 0-2v. Trying to work out if I have what I need, or a change of plan is needed. At first I though I could just use differential input mode, and put vIn- to gnd, Vref to 2, and vIn+ to sensor and sit back and enjoy, but now I am thinking I have made a mistake, and celebrating too soon...

author: xani
author_rank: Frequent Contributor
timestamp: November 14, 2017, 01:35:49 am
content: Quote from: KNSSoftware on November 13, 2017, 11:30:09 pmSetting input mode to single ended and PGA to +- 2.048 V would be enough, altho it would probably be more accurate if you used differental one. Just take care about voltage limits of input pins. And read datasheet, there is really everything you need there
0-30vdc variable powersupply? - Page 1
Forum section: electronics / beginners

author: Ian
author_rank: Contributor
timestamp: March 22, 2011, 11:53:41 pm
content: Hii would like to build a 0-30v DC variable power supply. it could be like 1.5v or 2.5v to 28v or 25v or 29v so basically what i am saying is that it does not have to go down to 0v and does not have to go all the way to 30v. I would also like it to have between 2.5a and 3.5a of of current. Also i would like it to have a maximum current output control so i can control the maximum current output. So i need a tutorial or a kit for this project.

author: Jon Chandler
author_rank: Frequent Contributor
timestamp: March 23, 2011, 12:03:28 am
content: Here's a way I made an adjustable power supply meeting some of your needs:Ten Buck Lab-Grade Variable Power SupplyIt uses an LM317 to regulate the output from a higher-voltage wall-wart switching power supply. It will handle up to about an amp depending on the voltage drop across it and has no current limiting but it's a easy starting point.

author: Ian
author_rank: Contributor
timestamp: March 23, 2011, 12:30:24 am
content: Thanks thats cool. Ya i have something like that

author: Zero999
author_rank: Super Contributor
timestamp: March 23, 2011, 07:11:43 pm
content: Yes, the LM317 is good for this but it's only rated to 1.5A, if you want more you'll need additional components.To cut down on power dissipation I'd recommend using a centre tapped transformer and switching to the centre tap for lower voltages; this can be done automatically if needs be.The minimum output voltage from the LM317 is 1.25V, to go lower you need additional components.

author: Hypernova
author_rank: Unknown
timestamp: March 24, 2011, 03:05:14 am
content: Look up TI's OPA54x series opamps that can deliver up to 10A from up to 80V, TI actually include example on how to make pot or DAC programmable PSUs out of them.

author: grenert
author_rank: Frequent Contributor
timestamp: March 24, 2011, 06:02:08 am
content: For a beginner, the LM317 is nice in that it has built-in short-circuit protection.

author: Ian
author_rank: Contributor
timestamp: March 24, 2011, 07:39:19 pm
content: thanks so much
0.4mm pitch BGA - Page 1
Forum section: electronics / beginners

author: ZeroResistance
author_rank: Frequent Contributor
timestamp: February 02, 2020, 07:23:45 pm
content: Hi,First time using a BGA, I have a 0.4mm pitch WLP package, 7 rows and 7 cols, The recommended pcb pad size for this is 0.25mm.Maxim has shown how to route this with 3 layers (image attached).My question is, this would require vias directly on the pads correct? so wouldn't the solder get sucked through the via hole during reflow causing a unreliable joint?Are these vias of a special kind?, I mean these don't seem to be the regular thru hole vias are there of the blind buried type?I was thinking of sending this to JLCPCB for board manufacture, but looks like their minimum via diameter is 0.45mm, so this seems to be beyond their capabilities, I have heard of Multech PCB too but never had any reviews of them, does anyone here gotten boards from Multech?

author: dmills
author_rank: Super Contributor
timestamp: February 02, 2020, 07:35:11 pm
content: 0.4mm is generally via in pad, filled and plated.EXPENSIVE in prototype quantities, and somewhat specialist, avoid if you can, otherwise someone like Wurths prototype shop can do this for you.

author: ZeroResistance
author_rank: Frequent Contributor
timestamp: February 02, 2020, 08:15:10 pm
content: Quote from: dmills on February 02, 2020, 07:35:11 pmThanks for your feedback, I'll stick to QFN for now.Are these the blind / buried kind of vias?I'd like to know what cost am I looking at for the 0.4mm via in pad PCB?

author: aix
author_rank: Regular Contributor
timestamp: February 02, 2020, 08:36:18 pm
content: I got curious and played with PCBWay's quotation system. It seems that four-layer boards with vias-in-pad start at around US$365 + postage.Also:https://www.pcbway.com/pcb_prototype/PCB_Via_in_Pad.html

author: ZeroResistance
author_rank: Frequent Contributor
timestamp: February 02, 2020, 08:45:25 pm
content: Quote from: aix on February 02, 2020, 08:36:18 pmThanks for the info, that's indeed very expensive !
0.5mm part, solder bridge - Page 1
Forum section: electronics / beginners

author: Skippy
author_rank: Contributor
timestamp: November 13, 2012, 12:58:16 am
content: In attempting to add some solder to a dodgy connection on a 0.5mm SMD chip, I've made a massive solder bridge across 4 pins. Solder wick just isn't cutting it. Any suggestions, or have I had it? It was basically working before as well

author: w2aew
author_rank: Super Contributor
timestamp: November 13, 2012, 01:17:37 am
content: Solderwick should work better if you add some flux. Even a vacuum desoldering tool (Solder Pull-it) may work well. Flux is your friend...

author: George_Race
author_rank: Regular Contributor
timestamp: November 13, 2012, 01:18:51 am
content: Melt the solder and use a small bristle brush to remove the solder. A solder sucker may also work as well.George

author: Psi
author_rank: Super Contributor
timestamp: November 13, 2012, 01:53:18 am
content: Yeah solderwick works the best (good quality stuff)Alternatively you can try the following two methodsMethod 1- First make sure the pins are cold, if you're trying this method repeatedly wait 10 sec between attempts so the pins can cool down. It works because of the temperature difference between two adjacent pins.- Apply some flux- Clean the soldering iron so they're are no lumps of solder on the tip.- Apply the soldering iron tip to one pin only. Pick a pin that's 1pin in from either end of the bridged section.- As the pin gets hot and the flux activates it will often pull the excess solder from the other pins onto the iron. (Basically the solder likes to flow to the hottest point and nearby pins are colder.)- Wait a few seconds and repeat to remove all the solder bridges.Another trick you can try, and its a bit counter-intuitive, is to put more solder on.- Add some flux- Put a small blob of solder onto the iron tip.- Run the tip (and solder blob) down the pins of the IC from one end to the other.- The excess solder will ball up on the tip and pull solder away from pins.- Doing this you can often move all the solder bridges to one end of the IC. eg, 5 solder bridges become one big bridge on the last pin.- To remove the last bridge just keep cleaning the iron and heating the pin up so it pulls solder away the pin and onto the iron.

author: johnwa
author_rank: Frequent Contributor
timestamp: November 13, 2012, 07:06:34 am
content: One other technique (which may not necessarily be successful on something this small) is to apply a blob of solder, then rotate the board and iron together until the joint is vertical, and the solder runs down from the joint onto the tip of the iron. This is also good for things like tinning copper tracks without leaving big lumps of solder behind.I agree with the suggestions to use some extra flux.
0-5Vdc to 2.2-2,8Vdc - Page 1
Forum section: electronics / beginners

author: aless2056
author_rank: Contributor
timestamp: May 11, 2020, 09:58:57 pm
content: Guys, how can I take a signal that varies from 0 to 5Vdc and convert it into a signal from 2.2 to 2.8Vdc.So, 0V will be 2.2V and 5V will be 2.8V.

author: Manul
author_rank: Super Contributor
timestamp: May 12, 2020, 12:20:49 am
content: This must be an exercise? Somehow it fits too nicely and practical use is hardly imaginable. Anyway, something like that (this not a complete practical schematic).

author: rstofer
author_rank: Super Contributor
timestamp: May 12, 2020, 12:42:53 am
content: See Chapter 4 of “Op Amps For Everyone”. Solve y=mx+b. Google for it...One op amp and 4 resistorsIt will have to be an inverting amplifier to get a gain less than 1. Use a second op amp to invert the result.So y=-(mx+b), I suppose.

author: Manul
author_rank: Super Contributor
timestamp: May 12, 2020, 01:21:00 am
content: Or it can be solved with a voltage reference and divider. But op amp with a reference solutions are more practical in my opinion, because things like DC shift and gain can be adjusted separately, more clearly and universally.

author: Manul
author_rank: Super Contributor
timestamp: May 12, 2020, 01:29:36 am
content: Quote from: rstofer on May 12, 2020, 12:42:53 amNice book, useful stuff