hybridfree/eevblog-posts huggingface dataset:
Emulate battery in charging state - Page 1
Forum section: electronics / general

author: Daniel28
author_rank: Newbie
timestamp: April 08, 2023, 03:04:43 am
content: [ Specified attachment is not available ]I am trying to build a circuit to emulate a lipo battery. Basically the circuit consists in a power supply to emulate the discharge behaviour and a variable load to eulate the charge behaviour. The circuit in a simplified way is in Circuit.pngThis basically generates 2 circuits, one to emulate discharge behaviour (with which I don't have any problem) and one to emulate charge behaviour. Charging circuit is in Charging circuit.pngCharging circuitThe issue that I'm having with this circuit is that, when I am emulating the charging behaviour the voltage generated by the power supply (which I use in the charging stage to emulate the battery voltage when charging) some of it's current is leaking through the variable load as shown in the picture by "Unwanted current". This is making the sensing of the current to be off and obviously to wasted a los of power because of that unwanted current. Current description is in Current description.pngIs there a way to "block" the current from going to the load? I thought of a diode in the load entrance but that will make the charging current to be blocked as well. Maybe some way to make the voltage coming out of the power supply to be only use as reference to maintain a battery charging voltage and not having that much current going through the load but how can I do that? Any suggestions?Thank you in advance

author: Siwastaja
author_rank: Super Contributor
timestamp: April 08, 2023, 05:23:46 am
content: How about a relay controlled by the microcontroller?

author: f4eru
author_rank: Super Contributor
timestamp: April 08, 2023, 12:31:22 pm
content: Just in case you are trying to build a current sink with an open loop linear mosfet:That will not work, it's basically uncontrollable.You need at least a closed current loop, with a fast response.

author: Daniel28
author_rank: Newbie
timestamp: April 08, 2023, 04:22:40 pm
content: Where can I put the relay so that it blocks power supply current but not the charger current?

author: Daniel28
author_rank: Newbie
timestamp: April 08, 2023, 04:23:38 pm
content: I am not having an open loop control. I have a shunt resistor connected to GND to measure current.
Suitable fuse for 50v low current circuit - Page 1
Forum section: electronics / general

author: wedwo1
author_rank: Newbie
timestamp: April 19, 2023, 02:53:49 pm
content: I have a DC-DC converter (50v to 5v) and have it connected to my 50v inverter battery circuit (200a capacity). The device consumes less than 1a. I'd like to use an in-line barrel fuse or other suitable protection in line on the positive but am struggling to find something low current in the 50v DC range. What should I be using?

author: mzzj
author_rank: Super Contributor
timestamp: April 19, 2023, 07:24:46 pm
content: ”200a capacity” inverter line probably has pretty high short-circuit so you need enough breaking capacity.6,3x32mm ceramic fuse likely, for example:https://www.farnell.com/datasheets/2349120.pdfhttps://www.farnell.com/datasheets/2345025.pdf
Totem Pole PFC at 300W is a marketing gimmick? - Page 1
Forum section: electronics / general

author: Faringdon
author_rank: Super Contributor
timestamp: March 28, 2023, 08:08:49 pm
content: Hi,At 300W, 100-265VAC, surely totem pole isnt much more efficient than straight BCM boost PFC?Totem pole controllers are always digital, so they consume probably about 2W bias power anyway.Is it worth it for a 300W PFC?I mean, what about BCM Boost PFC, with the two primary ground referenced diodes of the diode bridge made synchronous?......that surely has gotta beat totem pole PFC on efficiency at 75-300W?At some low power level, "Ye Olde" BCM boost PFC beats Totem pole on efficiency, where is that power level.....?..And here we have it.....it says for 300W applications, Plain old BCM Boost PFC , and totem pole PFC, have the same losses..https://www.monolithicpower.com/comparative-study-of-pfc-topologies-interleaved-boost-vs-totem-pole-pfc-topologiesThe below is surely a marketing gimmick?They want to flog more GaN?

author: Faringdon
author_rank: Super Contributor
timestamp: March 29, 2023, 06:25:26 pm
content: Hi,Does anyone know which semico makes Totem pole PFC controllers, and has the datasheet availabel on their website?Onsemi and monolithicpower.com do them, but you cant get the datasheet.

author: Faringdon
author_rank: Super Contributor
timestamp: March 30, 2023, 05:45:30 am
content: Hi,The following touts a 300W Totem pole PFC...The following says that at 300W, Totem pole PFC is not worth while (at 1:30)https://www.monolithicpower.com/en/catalog/category/view/id/995/Who is right?Also, Power Integrations have invested heavily, and built up a large stable of PFC controllers for 75-1000W, the "HiperPFS" range.....they are not trembling in their boots that Totem Pole PFC is going to wipe out their entire range, not at all...but why not?.......the demand in everything these days is for "smaller and smaller", and "more and more efficient"....and SMPS totally enclosed in plastic.....so why is Totem Pole PFC just so utterly failing to make the inroads expected of it?https://www.power.com/products/hiper/hiperpfs-4

author: Wolfram
author_rank: Frequent Contributor
timestamp: March 30, 2023, 08:30:07 am
content: There is not one correct answer, there almost never is. Successful engineering is often about tradeoffs, compromises and local optima, not the "one true solution that is best in all cases".Local optima can often shift as technology develops, especially in new and emerging fields like GaN power conversion.

author: jonpaul
author_rank: Super Contributor
timestamp: March 30, 2023, 01:08:45 pm
content: 99% ST Micro, 32WB many others.FTTS please do your own searching before you wasted our timehttps://www.st.com/en/evaluation-tools/steval-dpstpfc1.htmlj
Offline GaN  SMPS will survive blown FET? - Page 1
Forum section: electronics / general

author: Faringdon
author_rank: Super Contributor
timestamp: March 28, 2023, 05:39:40 pm
content: Hi,What do you reckon the chances are that this GaN FET blowing up has taken out the control circuitry aswell?It blew up on 240VAC.Its the hi side primary FET in a "very modified half bridge converter"I accidentally powered up and forgot i had open circuited the high voltage reset capacitor....so the FET got 650V+ drain to source and blew up.With Si FETs i often fInd you can get away with it, and the control circuitry and gate drive cctry etc would often be ok...what about with GaN?NV6128https://navitassemi.com/wp-content/uploads/2022/04/NV6128-Datasheet-FINAL-04-11-22.pdf

author: Gyro
author_rank: Super Contributor
timestamp: March 28, 2023, 06:53:19 pm
content: Quote from: Faringdon on March 28, 2023, 05:39:40 pmSurely our 'reckonings of chances' are completely pointless. It either has or it hasn't -youneed to debug / test it to determine which!

author: Siwastaja
author_rank: Super Contributor
timestamp: March 30, 2023, 08:39:43 am
content: Quote from: Faringdon on March 28, 2023, 05:39:40 pmI would not agree with that. Quite often the gate driver goes with the FET. I had once weird problems when the gate driver IC was partially damaged so that it's UVLO threshold voltage increased a bit but it worked otherwise, causing random issues near minimum operating voltage, that I made it a habit to always replace the gate drivers, too.

author: nctnico
author_rank: Super Contributor
timestamp: March 30, 2023, 10:48:43 am
content: Quote from: Siwastaja on March 30, 2023, 08:39:43 amSame here. My rule is to always replace the gate drivers in case a FET blows up. If not, chances are high the same device returns in a couple of weeks for another FET replacement.Things are even worse for a prototype; you will want to make sure all parts are in excellent condition. I make it a point to use only quality (A-brand) parts for prototypes.
Testing power supplies for FPGA boards  - Page 1
Forum section: electronics / general

author: joniengr081
author_rank: Regular Contributor
timestamp: March 28, 2023, 09:41:56 am
content: Hi,We are wondering how to test power supply prototype for FPGA custom board. What kind of load we can connect to test 5A, 10 A and even more at different voltages 1.0 V, 1.2 V and 1.8 V etc.
BISS0001 based solar lamp - Page 1
Forum section: electronics / general

author: hojnikb
author_rank: Contributor
timestamp: March 22, 2023, 10:00:38 pm
content: So i've picked up a cheap solar powered street led lamp based on this chipset. But it's a really wierd one. Firstly, i cannot find the PIR sensor, that is usually used on lamps that detect movement. But it does work somehow.But my biggest issue it's alway on when it's dark. It seems to have two different modes; a high power mode when movement is detected and a low power mode, that's always on until solar panel gets hit by some light.My question is, would it be possible to modify it so it would only light up when there's movement?Attached above is the circuit board in question

author: hojnikb
author_rank: Contributor
timestamp: March 25, 2023, 08:17:17 pm
content: So after a quick analysis of the board i've concluded that the Q2 transistor and R4&R5 resistors are being used as the dimmed, "always" on state. Simple removal of the transistor disables this mode and with R4&R5 resistors you can set the brightness (to a point, since Q2 ain't so big)
Sense resistor in switching node - Page 1
Forum section: electronics / general

author: Faringdon
author_rank: Super Contributor
timestamp: March 22, 2023, 09:35:35 pm
content: Hi,Today we wanted to measure the secondary current in the forward converter 240vac, 150w, 37vout.The thing is, due to it being the switching node (as attached), even though we twisted the flying probe to the sense resistor, it stops working, then starts again as soon as we remove the flying probe.Do you agree this is the switching node creating noise?....and when we solder the flying probe to the sense resistor, the flying probe acts liek a noisy antenna which stops the forward from working.We can remove wndings from a common mode choke. and wind 100 turns on it and use that as a sense transformer, but were hoping not to bother with that.As you can see, because the rectifier is capacitive coupled to the sec coil, both sides of the secondary are switching nodes....so looks like we are stuffed.
Is there a risk of blowing up electrolytic caps while doing hot air gun reworks? - Page 1
Forum section: electronics / general

author: Jim from Chicago
author_rank: Regular Contributor
timestamp: March 22, 2023, 08:44:45 pm
content: I was recently doing a rework where I had to replace a diode in a D2PAK package, so I used a hot air gun. There was an electrolytic cap right next to the diode and I was getting a bit nervous. The tech here recommends setting the hot air gun to 415C so that's what I set it at. Nothing bad happened in my case but is there a risk of something explosive happening in this type of situation?

author: T3sl4co1l
author_rank: Super Contributor
timestamp: March 22, 2023, 10:04:40 pm
content: Jesus christ, I get nervous putting mine over 280C, and they said crank it to, what, 415 must be the absolute max?!That's glowing hot!!(Very faintly, in a dark room.)Tim

author: aargee
author_rank: Frequent Contributor
timestamp: March 22, 2023, 10:25:14 pm
content: A piece of shaped sheet metal as a shield for the cap works wonders.

author: Faringdon
author_rank: Super Contributor
timestamp: March 23, 2023, 07:36:47 pm
content: yes, dont do it...caps are eg 105c for 10000hrs....if they go above that 105degc for even short intervals, there lifetime is seriously reduced.
Amprius Creates a 500Wh/kg Battery - Page 1
Forum section: electronics / general

author: pickle9000
author_rank: Super Contributor
timestamp: March 24, 2023, 01:41:53 am
content: They have a military spec battery using the same tech. Seems to be in production and the 500Wh/kg appears to be born from that.Patent of interesthttps://uspto.report/patent/app/20200274156
SMPS QUESTION - Page 1
Forum section: electronics / general

author: OutThere
author_rank: Contributor
timestamp: March 04, 2023, 05:32:37 pm
content: Is it acceptable on an SMPS, with the board removed from the power supply case OR powered up outside the case and then unplugged from the AC to short both of the capacitor leads together for the power electrolytic or any cap, if not what is the preferred way?

author: Jim from Chicago
author_rank: Regular Contributor
timestamp: March 20, 2023, 09:04:48 pm
content: Confused by the question. Why would you short the cap?

author: Faringdon
author_rank: Super Contributor
timestamp: March 20, 2023, 10:32:59 pm
content: To make sure caps are discharged?.....use a resistor with bits of wire to say alligator clips or something.....insulate yourself though, at all times.Dont just put eg pliers to pos and neg..it can damage the cap.Havign said that, there are actual resistive pliers you can buy, for shorting caps down to zero volts.

author: OutThere
author_rank: Contributor
timestamp: March 21, 2023, 02:55:16 am
content: Thats what i did. i ordered some 5 watt 10k resistors. going to put one on a short stick to discharge the primary filter caps

author: Magnethicc
author_rank: Contributor
timestamp: March 21, 2023, 07:09:17 am
content: Did you make sure that the electrolytic capacitors does not already have bleeder resistors soldered on the board?You can measure the resistance across the electrolytic capacitors, if there is a resistance then maybe you do not need to put yourself in danger just wait for the charge to bleed through the existing resistance.
Standalone "grid exporter" box? - Page 1
Forum section: electronics / general

author: rthorntn
author_rank: Frequent Contributor
timestamp: March 19, 2023, 01:23:56 am
content: Hi,I have an overly complex solar setup, my batteries are connected to off-grid inverters (MPP) that supply all my power, I do have the grid but I can't feed into it with these inverters. I do have a Growatt inverter that I can switch my panels to when I want to export.I'm basically looking for a device to allow me to feed-in to the grid a certain amount of amps for a certain duration at 240v whenever I like, so the export source is just my house load (which is really my batteries), is something like this available?I want to take advantage of providers likehttps://www.amber.com.au/that pay a lot more for exports when the sun isn't shining.Update: a friend of mine just mentioned using a rectifier connected to my load side and the rectifier output being connected to a panel input of a suitable grid tie inverter?Update: now we're thinking that it might be a case of "house AC" maybe isn't an acceptable energy source for exporters.So maybe we connect an additional grid-tie inverter (that support 48v batteries) and allows you to set export limits and we don't bother connecting any panels or the house load to it.Thanks.Richard

author: nctnico
author_rank: Super Contributor
timestamp: March 20, 2023, 09:58:20 am
content: From what I've seen at a glance is that modern day inverters may be able to do what you want. Perhaps start looking at Growatt as these seem to be the lowest cost devices with a reasonable quality.Keep a close eye on what your storage costs per kWh in batteries are though; battery storage is't cheap in terms of costs per kWh. Read the fineprint of a battery carefully, it will show you the amount of energy the battery can store. The Tesla powerwalls shows on Amber's website are amongst the most expensive; around US $0.40 or US $0.50 per kWh stored. So you'd need to be able to sell your electricity for way more in order to recoup your money.
AEM10941 has a LDO after a buck. Why? - Page 1
Forum section: electronics / general

author: Faranight
author_rank: Unknown
timestamp: March 04, 2023, 09:31:15 pm
content: Hello, can anyone please explain to me the logic behind this MPPT IC? I've been looking at thedatasheet, and on page 7 it shows the IC internal diagram. The IC collects energy from a small solar panel, and stores it in a battery or a supercap. Looking at the circuit, this stored energy is then delivered via two LDO outputs to the rest of the PCB - one output is for higher voltage (i.e. a transmitter) and the other one is for low voltage (i.e. low power MCU). What caught my eye is that the power path for the low voltage output (marked "LV load") is first directed through a buck converter (which supposedly lowers the voltage from whatever voltage is present on the battery down to 2.2V) and stored in an intermediate capacitor. The power is then sent through an additional LDO to the 1.2/1.8V output.So, I'm a bit baffled here. Why use a buck and a LDO in series? Why not simply use the buck alone and regulate the voltage to 1.2 or 1.8V or whatever voltage the user chooses by placing appropriate config resistors? It's more efficient than a LDO, yes?Ugh.

author: nvmR
author_rank: Regular Contributor
timestamp: March 05, 2023, 09:38:33 am
content: Usually the vbuck is noisy, and has a certain ripple, while the ldo is easier to control and quieter for the relevant output current.Vbuck is based on toggling the two switches, while the ldo sets a certain voltage at the gate, and responds to change at output. Less efficient - because efficiency is set only the the drop, but quiet supply.

author: Chat GPT (2)
author_rank: Newbie
timestamp: March 14, 2023, 11:09:56 am
content: The main function of the MPPT IC is to maximize the power output from a solar panel and efficiently charge a battery or supercapacitor. The internal diagram of the IC shows the different blocks of the IC and how they are connected to each other.Regarding the use of a buck converter and an LDO in series for the low voltage output, the reason for this is to achieve a lower output voltage with higher efficiency. A buck converter is an efficient way to step down the voltage from the battery or supercapacitor to a lower level, but it has a minimum output voltage that it can achieve. Below this minimum voltage, the buck converter cannot regulate the output voltage and the output voltage will start to droop. In this design, the buck converter is set to output a voltage that is higher than the final desired output voltage. The voltage is then regulated by the LDO, which can regulate the voltage to a much lower level with good efficiency.
Good place for off-grid hardware UK/Europe? - Page 1
Forum section: electronics / general

author: paulca
author_rank: Super Contributor
timestamp: March 13, 2023, 11:18:41 am
content: So at the moment, AliExpress are not only quite expensive, but takes ages to arrive. The cost of off-grid hardware like bus bars on Amazon is obscene. £60 a pair of 250A 6 way insulated NPC bars.When you start adding up 25mm^2 tails, lugs, isolators, din rail, bus bars and fuses they all seem to cost far too much.Are there any good, reasonably priced outlets in the UK which are worth using over Amazon or long haul from ALi?On bus bars. I have a suspicion that PPP is playing a part here. Product, price, placement. Bus bars marketted to off grid hobby solar folks or high end profressionals for the same, might involve these £50 a set bus bars. However, some other electrical or building trade might sell 3mm copper drilled bars for £3... and they could be pre-purposed.For the 240V side and even the <5Amp DC side I'm happy enough using wagos. It's the high current DC side I really need to put the effort into doing right. Not only are mistakes potentially fire, but voltage drop on LV DC is a right pain in the but.

author: paulca
author_rank: Super Contributor
timestamp: March 13, 2023, 11:24:01 am
content: I have noted that "brass" bus bars and hardware from the domestic electrical shops are "considerably" cheaper than nickel plated copper bus bars! It's just they usually don't quite come the way you need them.I'll go and see how much "tail blocks" are for meter boards.I mean, is there anything wrong with plated brass bus bars? What if I used these earth/neutral blocks with ferrules or if I just bolted the battery lugs to the screws themselves?https://www.screwfix.com/p/ced-4-way-earth-block/12386

author: themadhippy
author_rank: Super Contributor
timestamp: March 13, 2023, 12:43:18 pm
content: QuoteHenley blocks dear boyQuoteApart from the local wholesalers i also use tlc, prices may not be as competitive as amazon or ali,but you can be confident what your buying is what it says on the tin,not a close approximation
Phase load balancing - Page 1
Forum section: electronics / general

author: elektrinis
author_rank: Regular Contributor
timestamp: March 10, 2023, 01:53:19 pm
content: Short story: I am looking for active 3-phase power balancer, in other words a bidirectional inverter that will make sure all my phases are loaded equally even if I have various single-phase devices connected and actual phase loading is way out of balance.Around 3kW should be enough.I thing this should exist, but not sure what they are called and can't find anything.Are there such devices out there?Long story:I have a hybrid solar application on a 3-phase system. There is a problem with phase balancing, I mean a situation when two phases are loaded at 200W and one phase is loaded at 3kW because someone is boiling some tea etc.I am running the system in "zero power" mode, which means there is an inverter which tries to keep "imported" power at net zero, however in reality this ends up drawing 2600W from one phase and feeding back 1300+1300 on two other phases.The problem is that my energy company is actually counting these separately and charging me money for "returned" energy that I am taking from this single phase in this case.

author: Marco
author_rank: Super Contributor
timestamp: March 10, 2023, 04:00:51 pm
content: At that point it makes more sense to buy a better grid tied inverter.Your patch job would have to be done by an inverter as powerful as the one you already have, but with compounding inefficiency.

author: gf
author_rank: Super Contributor
timestamp: March 10, 2023, 09:15:06 pm
content: E.g. Victron Multiplus supports thathttps://www.victronenergy.com/media/pg/Energy_Storage_System/en/multiphase-regulation---further-information.html
Two current sense transformers reveal the current best? - Page 1
Forum section: electronics / general

author: Faringdon
author_rank: Super Contributor
timestamp: March 20, 2023, 08:29:14 pm
content: Hi,Customer has sent us 150W , 37vout offline SMPS (100-265VAC). They are told it is very special. They gave it to us to check it.We have no BOM or schem and no gerbers or layout. We only have the PCB.(i think 4 layer). It uses a PQ26/25 core.There is no output inductor. It kind of looks like a One transistor forward with high voltage reset. One pri and one sec coil. Sec coil is capacitively coupled to the output rectifiers. Neither end of the sec coil has a direct connection to output ground. (the mentioned series capacitors are “In the way”)We want to scope the power currents. However, we don’t know if the current , in whichever branch, is unidirectional, balanced bidirectional, or unbalanced bidirectional. As such, do you agree, we will get best depiction of the power currents by using two current sense transformers as in the following attached? (LTspice and jpeg)In the attached , the current is unbalanced bidirectional…..so using the two CSTs as shown , we are able to piece together what the actual current looks like. Would you agree this is the cheapest way? This is the best way..we cant afford a pricey high BW current clamp.Best to add the series cap..then no DC average component can flow in the secondary, and the CST can thus never saturate
High Pulsed currents from supercapacitors? - Page 1
Forum section: electronics / general

author: Faringdon
author_rank: Super Contributor
timestamp: March 09, 2023, 08:57:41 pm
content: Hi,We wish to pulse a laser diode block with 20A for 250ms every 2 seconds.(LTspice and jpeg as attached)We cannot draw this pulsation from the 2S Lithium Battery that we have , so we will charge up supercaps with the battery instead, and draw the pulses from the supercaps instead.We will use the VinaTech 25 Farad, 3V, 13mR ESR supercap…2 in series.VinaTech 25 Farad, 3V, 13mR ESR supercaphttps://www.vinatech.com/winko/data/product/WEC_3R0_506_QG_1840_data_sheet_%5B%C7%A5%C1%D8%5D_Ver1.3_85%B5%B5_%C1%B6%B0%C7%28R0%2C210201%29.pdfDo you think the supercap can handle these pulses?…(datasheet doesn’t allure to pulse rating) its only some 0.7W of power in each supercap

author: pardo-bsso
author_rank: Frequent Contributor
timestamp: March 10, 2023, 11:42:32 am
content: Given the cost and scope of this project you'll be better off just building a prototype to see for yourself.Pay attention to wire loop inductances and balance the caps. But I'm not sure why you can't use a different battery topology instead.
EG4 Life Power4 Li Ion batteries start up  , more batteries  for bigger loads ? - Page 1
Forum section: electronics / general

author: WiredSmart
author_rank: Contributor
timestamp: March 06, 2023, 06:35:13 am
content: Does the quantity of batteries connected up in parallel affect the start up of a load (say a compressor )I watched a video on someone connecting multiple batteries in parallel and testing what happens when you add too few batteries the load wouldnt even start upI assumed that a large load (compressor) would run on a single 5.2 kwh li ion battery at least for a short time . However in the video link here shows that the load simply would even turn on without connecting enough batteries in parallel. Since the battery voltage is the same why would a compressor not run for even a short time?. My limited knowledge of batteries are as follows:1)Batteries connected in parallel increases "the time" or the amp hour capacity2) Battery voltage stays the samelink of test can be found herefast forward to 6min approximately to skip time.

author: Kean
author_rank: Unknown
timestamp: March 06, 2023, 09:58:55 am
content: The key term is "inrush current" which he mentioned at around 6:45.Paralleling the batteries as shown doesn't just increase total run time (amp hour capacity) but also instantaneous current capacity.This kind of question would be better posted in theRenewable Energysection of the forum.

author: WiredSmart
author_rank: Contributor
timestamp: March 06, 2023, 10:47:51 am
content: Thank you for your valuable feedback, I'm still new to the site , i have a lot to learn on how the site functions as well as inrush current haha .Since inrush current is something I've overlooked, could you provide me with some pointers/ formula of how i can go about calculating the minimum amount of batteries needed to cope with the inrush current . Youve just added a new dimension i need to further develop my understanding around this topic .I'm looking forward to hearing from you again.

author: Kean
author_rank: Unknown
timestamp: March 06, 2023, 11:05:17 am
content: The need for the pre-charge circuit in the batteries that he discusses is because of the inrush current of the inverter. I believe he even demonstrated this in the video when talking about proper power on procedure.Further, even when the proper procedure is followed and the compressor load is turned on, there is effectively another inrush current event which trips the fault detection - thus the alarm condition. With more batteries in parallel the inrush load is shared between the batteries and thus doesn't trigger the fault detection or alarm.You should be able to find plenty of info about inrush current via a search here and on the internet in general, but the best advice will be from the suppliers of the batteries and inverters you are working with.Another related term for batteries that you might want to research is "internal resistance". There are many other installation and usage related factors that come into play as well, but these are probably the main ones.
Info about power measuring IC CL2208 needed - Page 1
Forum section: electronics / general

author: gashtaan
author_rank: Regular Contributor
timestamp: March 10, 2023, 09:42:59 am
content: Is there a chance anyone have datasheet, communication protocol specification or at least info about who actually manufacture IC specialized to power measuring with part number CL2208? The pinout doesn't match anything alike. It's used in some power meter device which I'd like to reuse for my project.

author: gashtaan
author_rank: Regular Contributor
timestamp: March 23, 2023, 04:28:17 pm
content: I just found out that it also have part number RN8209G, it is manufactured by some Chinese company called Renergy.Here is complete datasheet in case anyone is interested...
I caught exact moment when akaline battery started leaking - It makes a sound! - Page 1
Forum section: electronics / general

author: dusan
author_rank: Regular Contributor
timestamp: March 02, 2023, 07:25:41 am
content: Here is video where you can see it making bubbles and popping sound:This battery is Clever Alkaline AA (Sold in BILLA chain), was together with 2 other batteries inside automatic night lamp (with PIR sensor) in my bathroom. Prior to use it was in storage for few years. Yesterday I've heard a slight popping sound. It was air escaping from battery and as the bubbles popped it made a sound. The voltages of the batteries were:Clever Alkaline 05-2022 Charge Nr. 1948361815, 0.831V - leakVARTA high energy, Best before 12-2027, batch PD1017: 1.30V - no leakPairdeer industrial alkaline 04-2024, 0.98V - no leakCurrent is 160uA with these batteries and 300uA with fresh batteries. However it has 2 modes (led on/standby) and it runs maybe 20 times a day when current is 70mA for 1minute.Temperature in bathroom is 22C, humidity 40% but it is shower so it spikes once a day.

author: RoGeorge
author_rank: Super Contributor
timestamp: March 02, 2023, 09:14:20 am
content: Thanks for the info, good catch!Wouldn't be nice for battery compartments to have a microphone inside and a piezo buzzer to beep when a battery starts leaking...

author: Electro Detective
author_rank: Super Contributor
timestamp: March 02, 2023, 10:15:48 am
content: I assumed from experience that all leaking batteries made a'Ka-Ching'soundand benefit someone other than the victim holding the corroded item :'(
Best DC DC converter for NA5920-AL flyback? - Page 1
Forum section: electronics / general

author: Feyman_Follower
author_rank: Contributor
timestamp: February 25, 2023, 09:17:16 pm
content: Hello!Like the title I want to drive a NA5920-AL step up transformer 1:24 from Coilcrafthttps://www.coilcraft.com/en-us/products/transformers/power-transformers/power-converter-transformers/na6252/na5920-al/with a variable primary voltage between 8V and 20V, 1-2 A of current.I think a DC DC flyback converter IC is enough and I found the LT8304-1https://www.analog.com/en/products/lt8304.html.The problem is that, while the output voltage on this IC is easy to regulate, frequency is not, and maybe it will become a major problem.Is this component ok or something different would be better? Current could be also lower, slightly less than 1A

author: Faringdon
author_rank: Super Contributor
timestamp: February 25, 2023, 10:14:09 pm
content: What vout do you want?Also, the chip looks OK.Its boundary mode so thats good for reducing the turn on spike.Download LTspice and play with it there if you want.

author: Feyman_Follower
author_rank: Contributor
timestamp: February 26, 2023, 01:55:23 pm
content: I want to reach a variable 200-500V using a pot, my concern is frequency, that varies depending on the load (from a few KHz to 350KHz)

author: f4eru
author_rank: Super Contributor
timestamp: February 26, 2023, 02:56:21 pm
content: frequency is supposed to vary, depending on the chip strategy.Take care that a chip that is built to work without optocoupler feedback will not work properly in a no load situation, you'll have to provide a minimum load and accept some level of slack in voltage regulation....

author: Feyman_Follower
author_rank: Contributor
timestamp: February 26, 2023, 03:49:34 pm
content: Ok, thanks, I am thinking that a 200 Ohm 2W resistor in parallel on the primary coil could be a quick solution for that, or another IC would be better? One with an optocoupler?

author: f4eru
author_rank: Super Contributor
timestamp: February 26, 2023, 09:02:18 pm
content: won't work at the PI, put it on the output.

author: Faringdon
author_rank: Super Contributor
timestamp: February 27, 2023, 06:38:30 am
content: Boundary conduction mode is good for your app...use either a opto or bias coil for regulation.Any BCM flyback chip will be ok.You could use the opto.....and also have the bias coil to do overvoltage clamping.

author: pardo-bsso
author_rank: Frequent Contributor
timestamp: February 27, 2023, 11:48:09 am
content: Quote from: Faringdon on February 27, 2023, 06:38:30 am- Where is Treez / Faringdon and what have you done to them. Are they OK?
Thermalelectric Generator temperature delta for 10's of mW? - Page 1
Forum section: electronics / general

author: ChromaticMultiplexer
author_rank: Newbie
timestamp: February 25, 2023, 06:44:00 pm
content: Using a generic TEC or Peltier device, can anyone provide a rough temperature delta required to generate 10mW at about TEC 20mm x 20mm area?
TI InstaSPIN-FOC - Page 1
Forum section: electronics / general

author: stoyanoff
author_rank: Contributor
timestamp: February 23, 2023, 03:59:33 pm
content: Greetings! Is here anybody who is currently using or has used InstaSPIN-FOC? I am experiencing a lot of difficulties controlling ACIM with internal break. And the responces from TI are quite slow so I can use a little bit of help.Here is my problem! My motor is running in uf control(lab01c), I have fully identified it(lab02a) and it is working in close loop torque mode(lab05a). The problem is when I try to start the motor in simple instaSPIN-FOC project like lab03b where the offsets and Rs are recalculated and the motor should start immediately, my motor doesn`t spin. I think the flux is not enough and the internal break doesn`t stay released all the time. So what is the correct approach here? Increasing the motor max current, increasing motor max voltage, increasing Id or something else?Thanks!PP: Currently I am testing different options, but because the break doesn`t stay released, i overheat my motor quite fast and the process takes a lot of time...
Allen-Bradley gate driver card 690V - Page 1
Forum section: electronics / general

author: geggi1
author_rank: Frequent Contributor
timestamp: February 22, 2023, 12:39:07 pm
content: Hi!I'm looking for a source of Allen-Bradley gate driver card 690V.This is a multi layer card 3 or 4 layers.Our card have been shorted in one of the internal layers around the control volt input.The damage is inside the PCB sandwich and is most likely not repairable.We are looking for a replacement card, but it is discontinued at A-B.I can find the following marking.Sticker on the front: 789D 1903 0388 AS (this is most likely the the serial number)There is also a sticker on the front with 690V.On the back i can find in the silk screen ten following marking: E239218 94V-0 K-3|850The manual for the drive drive is here.https://literature.rockwellautomation.com/idc/groups/literature/documents/in/pflex-in023_-en-p.pdfDoes anybody know where it might be possible to get a replacement?
Kostal service code? - Page 1
Forum section: electronics / general

author: phamuc
author_rank: Contributor
timestamp: February 26, 2023, 09:56:03 am
content: Hello All,I am looking for my PV Kostal inverter, the service code so called "PARAKO-Passwort".Can any have and give me this password?Thank You,Paul

author: f4eru
author_rank: Super Contributor
timestamp: February 26, 2023, 02:52:43 pm
content: Hi,Would be helpful to have the exact model of inverter.Did you try to google "Kostal <model_of_inverter> service manual" in German and English ?
Sungrow PV battery systems bricked by firmware update - Page 1
Forum section: electronics / general

author: madires
author_rank: Super Contributor
timestamp: March 09, 2023, 04:15:34 pm
content: Last Saturday Sungrow bricked their PV battery systems, e.g. SBR096, with an automatic firmware update:-https://www.photovoltaikforum.com/thread/196471-sungrow-sbr096-fehler-932-735-739-833-%C3%BCber-nacht/?pageNo=1(German)-https://www.photovoltaikforum.com/thread/196498-ausfall-speicherbatterie-sungrow-sbr096-fehlermeldung-964-dann-724-735-739-dann/?pageNo=1(German)Since the battery systems can't be turned on again it's not possible to flash an old firmware version. The bricked BMS needs to be replaced.

author: Stray Electron
author_rank: Super Contributor
timestamp: March 10, 2023, 12:38:10 am
content: My understanding is that once something is BRICKED then there is no reviving it other than be replacing the Flash ROM with a properly programmed one.Was it an STANDARD update from Sunglow that bricked the system or were you trying Up-Hack it with modified SW?I don't read German but the site that you linked to only has one post about someone's system being bricked so you have to wonder what the circumstances were.

author: madires
author_rank: Super Contributor
timestamp: March 10, 2023, 07:43:35 am
content: It was a genuine update from Sunglow. And a lot of owners are affected.

author: Marco
author_rank: Super Contributor
timestamp: March 10, 2023, 11:12:40 am
content: Why make an OTA update system without a factory reset? It's just asking for trouble.

author: kripton2035
author_rank: Super Contributor
timestamp: March 10, 2023, 12:54:51 pm
content: Quote from: Marco on March 10, 2023, 11:12:40 amit's just cheaper...

author: Marco
author_rank: Super Contributor
timestamp: March 10, 2023, 02:55:33 pm
content: Quote from: kripton2035 on March 10, 2023, 12:54:51 pmMaybe if your business is structured to just immediately go out of business and be restarted under a different name when shit like this happens.Fixing this isn't going to be cheap.
High voltage LLC converter? - Page 1
Forum section: electronics / general

author: Faringdon
author_rank: Super Contributor
timestamp: February 13, 2023, 09:19:32 pm
content: Hi,For 2kW output, what is the highest voltage output LLC converter you can do?Vin = 400VDC.Anybody tired doing a 2kW, 8kV LLC with 8 series'd LLCs , each of 1kV output?Presumably best to do them from -4kV below earth to +4kV above earth?Custom bobbin....plastic spacer between pri and sec.Easy isnt it?Primarys are all paralleled...secondaries are stacked.The "top of stack" stage is having to refer its opto isolated signal through 4kV....so a special opto for that.Or maybe just do an RF signal for it.

author: jonpaul
author_rank: Super Contributor
timestamp: February 15, 2023, 01:53:25 am
content: FTTS

author: ahbushnell
author_rank: Frequent Contributor
timestamp: February 16, 2023, 12:28:27 am
content: Use a high frequency transformer.Andy

author: jonpaul
author_rank: Super Contributor
timestamp: February 16, 2023, 02:14:52 am
content: FTTS as always asks useless or misleading questions.So, HV DC..DC CONVERTERS are very old and well known.So, FTTS mixed up the converter architecture and topologies with the separate topic of the transformers design.Topologies..Flyback, resonant mode, bridge or double Foward.HV architecture...instead of FTTS complex multiple stacked suggestions, a Voltage doubler, quadrupler or Crockoff Walton multiplier are conventional solutions.The separate issues of HV HF transformers design, bobbins, insulation, winding techniques are detailed as,far,back as Tesla and Steinmetz!Just search and read HV and magnetics design texts, papers, seminars. Steinmetz (GE) , LBL, Stanford SLAC, (Hansen) Hughes , Fuji, Collier, Smith,....FTTS, Please should learn to do your own research, before you waste others time.j
Mystery of self-discharge of Li-Ion batteries solved - Page 1
Forum section: electronics / general

author: BU508A
author_rank: Super Contributor
timestamp: February 07, 2023, 07:38:05 am
content: Li-Ion batteries are suffering of unwanted self-discharge. This was a mystery for a long time but now it seems to be resolved.Scientists identified the PET tape which is being used to fix the battery pack as the root cause for the self-discarge.The related paper can be found here:https://iopscience.iop.org/article/10.1149/1945-7111/acaf44Abstract (Quote):Unwanted self-discharge of LFP/AG and NMC811/AG cells can be caused by in situ generation of a redox shuttle molecule after formation at elevated temperature with common alkyl carbonate electrolyte. This study investigates the redox shuttle generation for several electrolyte additives, e.g., vinylene carbonate and lithium difluorophosphate, by measuring the additive reduction onset potential, first cycle inefficiency and gas evolution during formation at temperatures between 25 and 70 °C. After formation, electrolyte is extracted from pouch cells for visual inspection and quantification of redox shuttle activity in coin cells by cyclic voltammetry. The redox shuttle molecule is identified by GC-MS and NMR as dimethyl terephthalate. It is generated in the absence of an effective SEI-forming additive, according to a proposed formation mechanism that requires residual water in the electrolyte, catalytic quantities of lithium methoxide generated at the negative electrode and, surprisingly, polyethylene terephthalate tape within the cell.

author: trobbins
author_rank: Frequent Contributor
timestamp: February 15, 2023, 09:57:52 am
content: A cause of, not the root or only cause of.
Massive reduction in SMPS undershoot and overshoot - Page 1
Forum section: electronics / general

author: Faringdon
author_rank: Super Contributor
timestamp: February 08, 2023, 12:12:04 am
content: Hi,Do you agree, what’s shown here is the future of SMPS? The attached shows a 120W Buck with very low output capacitance. (not needing to be electrolytic) However, even after a no_load to full_load transient , and vice versa, the output voltage does not go excessively high, and more importantly, does not go to zero , which may make microcontrollers reset etc.Just unhook the overshoot and undershoot comparators and see how much worse it is.This makes way for electrolytic capacitor free SMPS’s.Do you agree, this paves the way for a paradigm shift in the world of SMPS?

author: Phoenix
author_rank: Frequent Contributor
timestamp: February 08, 2023, 02:14:31 am
content: Nothing new in this idea. I've designed the control for a 50kW EV charger module with no electrolytic capacitors. It had a very similar high gain operation on the DC bus regulator that functioned only when the error was large.

author: uer166
author_rank: Super Contributor
timestamp: February 08, 2023, 03:04:50 am
content: Quote from: Faringdon on February 08, 2023, 12:12:04 amnah
nano-solar bench experiments. - Page 1
Forum section: electronics / general

author: paulca
author_rank: Super Contributor
timestamp: February 07, 2023, 02:14:17 pm
content: Hi,I'm looking to have a play with some mini solar panels on the bench, then work up from there to bigger panels.The first project I want to try is a solar powered MCU. The idea covers everything from MPPT to CCCV charging to boost/buck feedback loops.The panels I have range from ones about the size of a watch face to 6 inch square. From 100mW to alleged 3W.The basic idea I had was to take a small STM32, an 18650, buck/boost convertor and write the MPPT control logic for the buck/boost feedback (injecting a pwm signal to the adjust voltage divider). The MCU code is doing the boost/buck duty cycle regulation while moving the target output voltage to gain MPPT... or... run into "battery charge parameters" when they take over.There is a lot of fun coding to do there. With small micro panels the biggest risk is the 18650 battery.The thing I'm struggling with:Picking a boost/buck circuit to start with. I can pick from any number of chinese modules, but a lot of them seem to be aiming for much higher power and much lower efficiency than I will likely need to use small 1 watt solar panels.On the other extreme I can order some tiny little SMD IC that will do it all internally. Boring. In the middle are buck/boost adjustable regulator ICs with impressive efficiency figures, but only supply 200mA up to 5V. I believe it's something more like the later I need if I'm going to keep any power from the panel to charge the battery.There are dozens of these chips, so trying to locate a dev board or module to play with is tricky.Are there any "defacto" low power buck/boost ICs which are common enough to have dev boards on Ali/Ebay?Any other suggestions? I mean I could just use a mosfet, diode and coil, but I figured a bespoke buck/boost is likely to be inefficient?
Remote sense SMPS modules dont give enough info? - Page 1
Forum section: electronics / general

author: Faringdon
author_rank: Super Contributor
timestamp: February 05, 2023, 11:49:57 am
content: In a SMPS module with remote sense, there are always internal resistors connecting S+ to V+, and V- to S-.When you are also doing Load sharing, (with multiple modules in pllel), you absolutely need to know where these resistors are connected, and of what value they are….but no SMPS module with remote sense ever tells you these details in its datasheet.Why is this?Take the attachd LTspice sim where I do show the internal resistors, and the connectitons….as you can see, the value of the internal resistors must be told…so why do they not tell?

author: ejeffrey
author_rank: Super Contributor
timestamp: February 05, 2023, 06:16:26 pm
content: Don't do multiple module load sharing with remote sense. Load sharing relies on the resistance of the leads and/or the imperfect regulation of the supply itself to balance currents. If you use remote sense to counteract the lead resistance this doesn't work and they won't share the load effectively.If you need to parallel supplies and you need better regulation you need to use a setup where there is a single voltage feedback loop that commands current feedback loops on each module. Then they will share equally and you only need one sense connection.

author: dmills
author_rank: Super Contributor
timestamp: February 06, 2023, 09:51:45 am
content: How did I know that this was going to be a case of Farringdon going way off label?If you are buying enough to matter, get support from the vendors FAE, they will know the score, or just grab a module and measure with a handful of resistors to figure out the internal values.The right way to do this (which you usually cannot do with modules) is just to connect the comp pins of the current loops together, and organise a suitable number of phases, that usually just works.

author: Faringdon
author_rank: Super Contributor
timestamp: February 06, 2023, 07:28:12 pm
content: QuoteThanks, we want to do Load Sharing using the Remote Sense connections, as per page 1 of the UC29002 datasheet..Sorry, did i appear to sat that we wanted to do both Load sharing and Remote Sense together?....my apologies.......(indeed that is for a future investigation)UCC29002https://www.ti.com/lit/ds/symlink/ucc39002.pdf?ts=1675672947985&ref_url=https%253A%252F%252Fwww.ti.com%252Fproduct%252FUCC39002%253Futm_source%253Dgoogle%2526utm_medium%253Dcpc%2526utm_campaign%253Dapp-null-null-GPN_EN-cpc-pf-google-eu%2526utm_content%253DUCC39002%2526ds_k%253DUCC39002%2526DCM%253Dyes%2526gclid%253DEAIaIQobChMI79Wk97-A_QIViIjVCh3bbQz9EAAYASAAEgLXsfD_BwE%2526gclsrc%253Daw.ds
Cisco PSU (PS-2651-1-LF) - Page 1
Forum section: electronics / general

author: ArCoN
author_rank: Contributor
timestamp: February 04, 2023, 01:17:28 pm
content: Hi AllDoes anyone know how to power on the 12v rail on that psu?I can't find the pinout for it.Just for pic.https://parts.metservers.com/ps-2651-1-lf-cisco-650w-power-supply-c220-m3-c240-m3B.R.