hybridfree/eevblog-posts huggingface dataset:
Charging 18650 LiPo cells via BMS, using a non-constatant current PS - Page 1
Forum section: electronics / general

author: bill6560
author_rank: Newbie
timestamp: June 11, 2024, 06:39:15 pm
content: Hello all,I'm in the process of building a 4S/14P power pack (for ham radio use**) using 18650 LiPo 2600mAh (2.6Ah) cells, for 16.8V (4.2Vx4) at 36Ah total. With the battery pack, I'm using a smart JK-BMS 4S BMS for charge/discharge control. I don't have a constant current power supply for charging, but what I intend to use is a regulated 18 Volt (±10%), 180W, 10 Amp switching PS to charge the pack, with the PS's voltage output set to 16.8 Volts. The PS (https://www.amazon.com/dp/B07STRPMFY) specs state that load current should limited to 80% of rated current, or about 8 Amps for safe use.My question is, using this non-constant current PS, the maximum charge current will be limited to PS's 8-10 Amps. If my math is correct, for 14P cells, at 10A that's about 714mA (0.28C), or at 8A that's about 570mA (0.22C) charge current per cell. The PS does have Over Current, Over Voltage, and Short Circuit protection.Another unknown is whether the BMS will control the charge current to limit it to 8A, however the JK-BMS app does have a setting for "Max Charge Curr (A)".Will this work and be safe for the cells?Thanks,Bill** P.S. To limit the initial voltage of the pack's 16.8V, I'm inserting a 60A full bridge rectifier in series to limit the voltage to a safe 15.4V for my ham gear. Once the pack settles down to it's nominal 3.6V/cell voltage (~14.4V at 4S), I'll switch out the bridge rectifier.

author: Simon
author_rank: Unknown
timestamp: June 12, 2024, 08:44:45 am
content: Please don't double post. It will make you very unpopular as people feel you are wasting their time.Thread locked.
H V power for PM - Page 1
Forum section: electronics / general

author: Salma
author_rank: Newbie
timestamp: May 24, 2024, 02:04:50 pm
content: Hello,I am trying to revive an analog HV power, 0.1 kV to 3.0 kV , 30 mA, manufacture: SIEMEL, that is normally used for a photo multiplier.The problem is that the the fixed power (on the potentiometer) is not the same given by the needle.For a fixer 0.1 kEV I measure a power higher than 1 kV y my voltmeter !I have not yet found a data sheet about it and no idea how to start !Thanks,

author: jonpaul
author_rank: Super Contributor
timestamp: May 25, 2024, 01:09:49 pm
content: What meter used to measure?Is it capable of 4,000V?Never heard of that mark (brand) or model.Get the manual and schematicj
Need help with finding non conductive tools for EV battery repair - Page 1
Forum section: electronics / general

author: tj_theEE
author_rank: Newbie
timestamp: May 21, 2024, 09:16:11 pm
content: I am currently working at the EV division of my company and one of the responsibilities i was given was to repair EV batteries. Problem is, our EV batteries are hard to dismantle, not to mention the risk of dismantling an EV battery with improper tools that could lead to hazardous situations. Can anyone recommend me some non-conductive dismantling tools for EV battery pack repair, especially for prying things open? I understand that this act is really unsafe but there's nothing i can do at my current position other than making it less risky for me and my coworkers. So if anyone can recommend me some international brand name tools that would be great.

author: thm_w
author_rank: Super Contributor
timestamp: May 22, 2024, 12:51:35 am
content: Google is your friend:https://www.homedepot.com/p/Nupla-35-in-Composite-Fiberglass-Pry-Bar-Certified-Non-Conductive-with-Single-End-and-Curved-76601/203531519Then get the regular selection of high voltage tools, offered by wiha/klein/whoever.https://www.wihatools.com/collections/insulated-screwdrivers

author: NiHaoMike
author_rank: Super Contributor
timestamp: May 22, 2024, 03:40:58 am
content: If you're only dealing with a few types, design jigs to cut them apart in a controlled manner.

author: jbb
author_rank: Super Contributor
timestamp: May 22, 2024, 07:22:12 am
content: Excellent idea!
One load, many sources? - Page 1
Forum section: electronics / general

author: LM21
author_rank: Regular Contributor
timestamp: May 12, 2024, 05:57:54 pm
content: I want to load several power sources so that they all contribute. All sources come and go randomly. Power is probably from watts to tens of watts. What I know now, power sources are small windmills. They give AC.I was thinking about unregulated fly back regulators, one for each source.

author: mariush
author_rank: Super Contributor
timestamp: May 12, 2024, 06:32:31 pm
content: My first thought was that the easiest solution would be for each output to power some kind of water pump filling a water tank, then at the bottom a generator can generate power at a continuous rate from the water pouring out from the reservoir.Waste of energy, lose efficiency, but would be simple.Next thought was converting everything to DC at a fixed voltage like 48v for example, and then using a bunch of dc-dc controllers connected together, like LTC7871 :https://www.analog.com/media/en/technical-documentation/data-sheets/ltc7871.pdfThe IC supports up to 24 phases (connecting 6 chips to each other, 6 phases on each chip) and you supply each phase with up to 100v (48v in my example) from one input or another ... and boost that or buck that to whatever voltage you want (example 14v or 28v to charge up a LifePo4 battery / Lead Acid battery) or just buck-boost to 48v to power things.The problem is making sure each phase would receive the enough current based on the output current draw ... I'd probably have some p-channel mosfets or something to disconnect an input if the current is too low... for example if there's one source that can do 48v 0.5A and one that can do only 48v 0.1A , maybe it's better disconnect the second and connect the first to the second phase as well, and have 2 48v 0.25A phases.

author: NiHaoMike
author_rank: Super Contributor
timestamp: May 12, 2024, 09:25:12 pm
content: I would say a separate boost converter from each input to a common rail, then (if needed) a buck converter to the final voltage.

author: LM21
author_rank: Regular Contributor
timestamp: May 13, 2024, 04:50:27 pm
content: Good suggestions. I remember how smooth a rectified 3-phase voltage is. More phases may work also here. But each phase may come and go, depending on the wind.

author: jbb
author_rank: Super Contributor
timestamp: May 16, 2024, 01:57:22 am
content: This sounds like an interesting problem. Could you maybe sketch what you’re interested in doing?Are you interested in maximising energy capture? If so, you would want a controller for each windmill.How far apart is everything? A 48V DC common bus may not be the best solution (eg if distances are short 24 V or even 12 V may be OK). Likewise, is this going to be indoors or outdoors?
USB fan looks like a resistive load? - Page 1
Forum section: electronics / general

author: Faringdon
author_rank: Super Contributor
timestamp: June 02, 2024, 02:14:22 pm
content: Hi,Would you agree, a low voltage (12v) DC fan , with a BLDC driver in front of it, looks like a resistive load, and not an inductive load?

author: Andy Chee
author_rank: Super Contributor
timestamp: June 03, 2024, 06:50:00 am
content: It completely depends on the load on the fan blades.For example, if you stuck your finger into the blades and stalled the fan, what do you think the current and voltage waveforms would look like?Or if you did a massive long fart into the fan and cause it to "windmill", what do you think the current and voltage waveforms would look like?

author: Whales
author_rank: Super Contributor
timestamp: June 03, 2024, 06:59:44 am
content: It depends on how much approximation you can tolerate. What is the goal of this approximation?Generallyyou don't approximate active electronics as R or L; instead you add lots of power rail capacitance in parallel so that you can pretend that it's a capacitive load with some varying parasitic resistance.Do you care about turn-on transients? It will look like a big capacitor.Do you care about transients during motor load changes? It might look inductive if you try and change the supply voltage because the motor can back-drive the H bridges and act as a generator.Does the driver support regen modes?
Solar Power Grid Feed-in question... Just had solar and battery installed - Page 1
Forum section: electronics / general

author: squibby
author_rank: Contributor
timestamp: May 15, 2024, 12:29:30 am
content: Hi guys,I just had solar upgraded at my property. The installer did a tidy job, but the electrician made couple very minor errors, it was a friday.He's possibly made a Human error and the grid feed-in has not been restricted to 5KW.I get paid $0.08 per kwh. Now obviously I understand the reasons why energex would restrict grid feed in to 5kw, but my question is... since a human error has been made by others, and they are receiving up to 10kw of energy whether they want it or not, does anyone know if their meters are clever enough to only pay me for the 5kw maximum they said I could sell to them, and they simply pocket the extra free of charge. Or do you reckon it'll register all the excess in error and end up crediting the excess beyond the 5kw to my account so that I get paid for the extra?Obviously, the answer has a great bearing on whether I shall fix this human error or not....
Solaredge power optimisers with 3rd party inverters - Page 1
Forum section: electronics / general

author: Skrep
author_rank: Newbie
timestamp: May 14, 2024, 11:04:59 am
content: Hi guys,I was wondering if anyone here has unlocked the solaredge optimiser to be used on 3rd party inverters.I understand that you require the se1000 key from solaredge to unlock them. These keys seem to be hard to find here is Australia.Does anyone know of the communication protocols they use to unlock these optimisers?
Where to obtain ExcellentIT Transformer Calculator Tool ? - Page 1
Forum section: electronics / general

author: ScoobyDoo
author_rank: Regular Contributor
timestamp: May 06, 2024, 05:47:27 pm
content: Hello - I have attached the canvas (GUI) of a Transformer Calculator Tool ...Can someone tell me where to download or where to get the latest version of this tool ?Are You aware of similar tools to calculate various Push-Pull|Half-Bridge|Full-Bridge topologies ?Thank You very much !Best regardsScoobyDoo

author: jonpaul
author_rank: Super Contributor
timestamp: May 07, 2024, 05:32:46 am
content: Bonjour cher Monseiur:Je vous advise consulter les engines serach eg duckduckgo.https://www.diysmps.com/forums/index.php?threads/calculation-programs-for-transformers-and-inductors.522/page-7We use the old MicroCap Magnetics for decades.But your post is unclear if you need magnetics design or SMPS design tool.Bon chance!AmicalmentJonPS: The best word for the GUI "canvas" in English is "Screenshot"

author: uer166
author_rank: Super Contributor
timestamp: May 07, 2024, 05:51:54 am
content: Quote from: jonpaul on May 07, 2024, 05:32:46 amMy guy/girl literally provides screenshot of the software they need specifically and you plug something completely unrelated.OP: see attached ZIP I found in a Russian forum, seems to be the original author's.
Charging LiFePO4 Battery Banks - Page 1
Forum section: electronics / general

author: Zucca
author_rank: Unknown
timestamp: May 02, 2024, 03:45:49 pm
content: I found it very interesting, did not check if it was already posted...https://nordkyndesign.com/charging-marine-lithium-battery-banks/Especially the charge termination limit vs VBatt interpolationTLDR: It is possible to overcharge a LiFePO4 even at 3.5V... it made me change my charging parameters...

author: f4eru
author_rank: Super Contributor
timestamp: May 05, 2024, 01:09:57 pm
content: Interesting. Was suspecting this for some time, for all kinds of batteries, usually on Pb batteries the "float" charge voltage recommendation is also lower than the "one time" charge peak.
Synchronous Buck with Schottky anti-parallel to Synch FET? - Page 1
Forum section: electronics / general

author: Faringdon
author_rank: Super Contributor
timestamp: April 23, 2024, 07:24:30 pm
content: Hi,Why do they bother with the SMA Schottky in this Synch Buck. (B360A-13-F)?At the currents being switched , the internal diode in the Sync FET will have a lower vf than that Schottky, so its pretty much a waste of time?D4 shows Schottky:https://www.ti.com/lit/df/tidmb83/tidmb83.pdf?ts=1713876988568&ref_url=https%253A%252F%252Fwww.ti.com%252Ftool%252FPMP31210B360A-13-Fhttps://www.mouser.co.uk/datasheet/2/115/DIOD_S_A0002833511_1-2542242.pdf

author: NiHaoMike
author_rank: Super Contributor
timestamp: April 23, 2024, 10:15:57 pm
content: Some designs disable the low side drive at light load, under that condition synchronous rectification uses more power than it saves.

author: __steven
author_rank: Newbie
timestamp: April 30, 2024, 01:37:10 pm
content: I remember reading that it is less so about the forward voltage drop and more about the reverse recovery characteristics of the diodes in question. Almost all IC's have deadtime between when the switches are turned on. During the deadtime, both switches are off, and the low side FET's body diode conducts. This can cause voltage spikes on the output during the body diodes reverse recovery. Sometimes a diode with better reverse recovery characteristics compared to the body diode is used to avoid this.The datasheet specifies 22ns which seems pretty reasonable, and schottky diodes are pretty much a requirement for this. I could not find the original paper that I got this information from, but a quick google search brought me this:How a Small Schottky Diode Minimizes Noise in Synchronous Converters:https://ez.analog.com/ez-blogs/b/engineerzone-spotlight/posts/how-a-small-schottky-diode-minimizes-noise-in-synchronous-convertersYou may be right however, if during inductor commutation the external diode has a greater voltage drop than the internal diode, the external diode may not conduct at all. I imagine that these diodes are primarily for lighter load conditions, less than 10Amps by looking at the datasheets.Let me know what you think.Steven

author: Faringdon
author_rank: Super Contributor
timestamp: April 30, 2024, 06:20:33 pm
content: Thanks, i guess even an SMA Schottky , even if it has to conduct 17A for 50ns or so, it'll take some of the current out of the fet's own diode, and thus reduce reverse recovery current, and hence reduce noise, and slightly increase efficiency.

author: langwadt
author_rank: Super Contributor
timestamp: April 30, 2024, 07:47:54 pm
content: Quote from: NiHaoMike on April 23, 2024, 10:15:57 pmif the FET's body diode was good enough for normal operation it would also work when off
Li-ion battery safety - charging vs standby - Page 1
Forum section: electronics / general

author: Circlotron
author_rank: Super Contributor
timestamp: May 06, 2024, 09:55:37 pm
content: With regard to Li-ion battery fires, if they are charged at too high a voltage and consequently begin to overheat there is a risk of catching fire. But what about after they are charged properly and just sitting around. Is there still a risk of something happening? For example, is my rattle gun that has been sitting in the shed for six months untouched something to be concerned about, or should the battery be removed and put in a strong metal box? What about as the battery gets older despite not having done hardly any work?

author: thm_w
author_rank: Super Contributor
timestamp: May 06, 2024, 10:49:40 pm
content: Power tool batteries from major brands tend to be fairly reliable when properly handled, there are some reports of fires but not too many. The failure can occur during charging, during use, or in storage. If you want to be completely safe then yes you'd store them on a solid metal bench or metal cabinet and have a working smoke detector in the room.In your case, a shed burning down probably isn't the end of the world though.https://www.worksafe.govt.nz/about-us/news-and-media/battery-fire-in-underground-storage/
DIY Battery Bank from Recycled 18650 - Page 1
Forum section: electronics / general

author: FinOminal
author_rank: Newbie
timestamp: April 28, 2024, 11:00:24 pm
content: Someone on facebook is selling these:I attempted to let the seller know this is a dangerous build, but they don't seem to care.I thought it would be worth while getting opinions (technical and rational) from the community so they can see that it's not just me being annoying.What are your thoughts on using random batteries that are soldered together in this way?

author: FinOminal
author_rank: Newbie
timestamp: April 28, 2024, 11:12:12 pm
content: more pics from their add on facebook

author: ledtester
author_rank: Super Contributor
timestamp: April 29, 2024, 05:17:22 am
content: What are those things in a glass package? Fuses?

author: nctnico
author_rank: Super Contributor
timestamp: April 29, 2024, 07:24:47 am
content: Quote from: FinOminal on April 28, 2024, 11:00:24 pmFantastic, if you want set your home on fire. This is wrong on so many levels. It basically goes against all good practises where it comes to building Li-ion battery packs. The fuses will not help against the number one issue: when a Li-ion cells goes off, the thermal runaway will ignite the surrounding cells.

author: mtwieg
author_rank: Frequent Contributor
timestamp: April 29, 2024, 12:01:14 pm
content: Quote from: ledtester on April 29, 2024, 05:17:22 amI assume they're fuses. I'd like to ask them why they're only used on specific cells...

author: shapirus
author_rank: Super Contributor
timestamp: April 29, 2024, 12:35:19 pm
content: Depends on application.(the build itself is weird regardless of application, though)

author: BrokenYugo
author_rank: Super Contributor
timestamp: April 29, 2024, 01:00:55 pm
content: Hundreds of crappy solder joints on something you're supposed to spot weld.No insulation.Mixed mystery cells.No BMS/protection.That's just what I see not knowing anything about the details of lithium bank assembly. I just report and move on in this sort of situation, all you can really do.
Munro:  Inside the Tesla Cybertruck Battery pack. - Page 1
Forum section: electronics / general

author: max_torque
author_rank: Super Contributor
timestamp: May 22, 2024, 02:01:41 pm
content: It would be interesting to see a more detailed discussion around the power convertor! It seems from the devices shown that the latest gen unit has an almost total abscence of bulk filtering capacitance compared to the earlier generation unit?

author: Wolfram
author_rank: Frequent Contributor
timestamp: June 05, 2024, 11:52:25 am
content: Quote from: max_torque on May 22, 2024, 02:01:41 pmIt's a full 4x4 matrix converter without any intermediate DC bus storage. 100 % battery current ripple in single phase operation, though very little in 3 phase mode, which it also seems to support.

author: Siwastaja
author_rank: Super Contributor
timestamp: June 06, 2024, 06:34:56 am
content: AFAIK, li-ion batteries can take ripple very well (I have also ran some tests myself for a customer who wanted to test the scenario of 100Hz rectified AC ripple, and within some hundreds of cycles, did not see any worse degradation), so it makes sense not to filter. Especially since the charge rate (compared to pack size) would be small.Without unnecessary filtering, you save cost of unnecessary components, and easily get unity power factor by just copying the input voltage waveform as charge current waveform.
Meaning of "Single point ground"? - Page 1
Forum section: electronics / general

author: thomasx
author_rank: Contributor
timestamp: April 21, 2024, 02:54:43 pm
content: HiIn the layout recommendations in the datasheet for the UCC28C54Q flyback controller, they mention "Single point ground". It is not clear to me what they mean by that.The signal ground has lot's vias between top and bottom, do these NOT connect with the internal ground plane?Also some of the components connecting with the power ground are through hole components, do these pins also NOT connect with the internal ground plane?Is the "Single point ground" the only connection with the internal ground plane, or what do they mean?Thanks!

author: Faringdon
author_rank: Super Contributor
timestamp: April 21, 2024, 08:13:41 pm
content: Its a layout methodology to help you to avoid running power switching currents with high di/dt through lengths of your control ground.Eg the output divider, say, connects to ground, and the controller connects to ground also, but if high di/dt runs in the copper between these connection places, then theywont really be at the same potential. Since V = L di/dtAttached is a doc on it.
DIN 41773-1 - Page 1
Forum section: electronics / general

author: Njk
author_rank: Frequent Contributor
timestamp: April 11, 2024, 12:12:18 pm
content: The world is full of ridiculous things. Consider StVZO. This abbreviation is mentioned in a lots of marketing materials (mostly from Asia). But no competent lawyer or legislator will refer to it because it's long time dead and the related requirements were moved to ISO 06742, etc. As for DIN 41773-1 ("Static power convertors; semiconductor rectifier equipment with IU-characteristics for charging of lead-acid batteries, guidelines"), one thing in common is that it's also not relevant now. But I'm not aware of the replacement. If no corresponding ENs were provided, why it's withdrawn?

author: f4eru
author_rank: Super Contributor
timestamp: April 12, 2024, 01:48:07 pm
content: I think you conflate two different things.StVZO is a law, in Germany.ISO 06742 does not exist (should be a norm?).Laws and norms are not the same thing...Some norms are only a guideline.Some norms are referenced by laws, and are mandatory to follow under some conditions.

author: Njk
author_rank: Frequent Contributor
timestamp: April 19, 2024, 01:46:44 pm
content: Quote from: f4eru on April 12, 2024, 01:48:07 pmSeems the leading zero resulted in the confusion. My badhttps://www.iso.org/standard/82576.html
Hobby BLDC ESC snsor connections - Page 1
Forum section: electronics / general

author: Circlotron
author_rank: Super Contributor
timestamp: April 18, 2024, 05:28:13 am
content: Looking on ebay for a small electronic speed control for a PMSM with sensors. The motor I want to use it on has 3 sensors, so a ground wire and three others. Many of the sensor ESCs I have looked at seem to only have 3 sensor wires, red, black, white. Is this for a potentiometer connection instead? So how would connect three sensors? Example ESC ->https://www.ebay.com.au/itm/315093498324?itmmeta=01HVQT2F6ED5QHD9GKQXH79FK0&hash=item495d0939d4:g:bv4AAOSwkz1lojwl&itmprp=enc%3AAQAJAAAA8MSg8sdXiwgJOAvXwOYbBAWlrRL93sAXiw3NYa4fA5r5cQ9Uki4fI6PpcXgkGaTaXxZwj5uWTMyT4YG4L%2BIXsKIFBWkthLR3G2NgAFypSxUn5TL8%2FUWSyV2%2BgSPQ7NWiNrzUvmrIRO5ACU%2ByJZCR9azgFr2GhZAABKm8JAFOXSr%2BHgU95sn5ZL9sHkd2Kpy8e2AwVwa3so5NRX7o8Wtuji21tr7d07GlY9xWfqOHxROQ%2Fp3NhKQr%2BnJQdSthmh94%2B5S6cymCXpwJ65JWNtuyrJJM5f0EwB3Kz9L%2FG0w153NoM5dw7TztgAAYL1xICRo5aA%3D%3D|tkp%3ABk9SR7DzifrdYw

author: mtwieg
author_rank: Frequent Contributor
timestamp: April 21, 2024, 02:23:58 pm
content: Actually I would expect five wires for the sensors, typically they need both GND and a supply voltage. Long ago I took apart some old BLDCs and found some with passive sensors (some had pickup coils, others seemed to have two-terminal magnetic sensors, maybe magnetoresistive?). But I would never expect to find exotic stuff like that in a toy ESC like this...

author: langwadt
author_rank: Super Contributor
timestamp: April 21, 2024, 03:15:45 pm
content: I'd expect the red-white-black to be for the RC-servo like pwm signal to control the ESC

author: Circlotron
author_rank: Super Contributor
timestamp: April 22, 2024, 04:36:16 am
content: Quote from: mtwieg on April 21, 2024, 02:23:58 pmFive wires... oh yeah, of course.After looking a bit further I found an e-bike controller that should do just what I want. There are heaps of these available at very low prices. I just want to mess around on the bench with a motor that is about the size of a coke can.https://www.ebay.com.au/itm/404922267506

author: mtwieg
author_rank: Frequent Contributor
timestamp: April 23, 2024, 12:18:50 pm
content: Quote from: langwadt on April 21, 2024, 03:15:45 pmYou're right, it does look just like a RC servo pwm cable. But that makes no sense on a BLDC controller (unless it's used to control speed, not position).Quote from: Circlotron on April 22, 2024, 04:36:16 amWell that does have five wires for the sensors, at least. e-bike/e-scooter controllers like those are probably a good option, so long as you have decent documentation for them.

author: langwadt
author_rank: Super Contributor
timestamp: April 23, 2024, 12:31:29 pm
content: Quote from: mtwieg on April 23, 2024, 12:18:50 pmplenty of bldc controllers with rc servo pwm interface for controlling speed
Our L2 48A charger having issues with Hyundai Ionniq & Kia EV6 - Page 1
Forum section: electronics / general

author: Dlou87
author_rank: Newbie
timestamp: April 03, 2024, 06:50:07 pm
content: Hello, we are a manufacturer and have a very solid track record with not having any issues charging all the various models out there. In addition we recently modified our design to have a wider tolerance.Even with this design we have a report of customer pulling up on a Hyundai Ionniq & a Kia EV6 and having charging issues.Does anyone know what could be the cause? Why these vehicles specifically?Thank you!

author: Lstkartagi
author_rank: Contributor
timestamp: April 03, 2024, 08:05:00 pm
content: Quote from: Dlou87 on April 03, 2024, 06:50:07 pmIoniq 5 had at least two different problems charging L2 at 48A, overheating of the J-1772 input port and overheating of the ICCU (the I5 AC charger under the rear passenger seat). There have been numerous service notes and software updates. On the connector side, they have service check the connections and replace the connector and internal car cable as needed. On the software side, at least in the first update, they automatically limit the current down within the car ICCU control presumably as needed based on temperature rise. EV6 had similar problems.This is probably not the best forum. Probably best to review threads (there are many) at the main IONIQ 5 and EV6 forums before posting there:https://www.ioniqforum.com/https://www.kiaevforums.com/These problems were kind of ironic, because with the 800V architecture, I5 and EV6 are among the fastest BEVs to charge at DC fast charge stations. However, at home, they proved to be "delicate" at best above L2 32A. I traded my I5 in, in part because of the constant ICCU problems. Driving a Cadillac LYRIQ now, which charges flawlessly at 48A, some LYRIQs are L2 80A capable too!
One transistor forward with avalanche reset - Page 1
Forum section: electronics / general

author: Faringdon
author_rank: Super Contributor
timestamp: April 01, 2024, 05:30:09 pm
content: Hi,We took apart a product, and found it to be a One Transistor Forward , but with no reset winding, and no primary clamp.The magnetising inductance, and leakage inductance, were just getting reset by way of the primary FET repeatedly avalanching.Would you declare this to be unreliable?

author: tggzzz
author_rank: Super Contributor
timestamp: April 01, 2024, 05:52:48 pm
content: Quote from: Faringdon on April 01, 2024, 05:30:09 pmDon't you mean "would you agree this is unreliable?" ?Is it a Chinese product?What are its specifications?What is the design lifetime? After all, WW2 bomber engines weren't reliable, but statistically they only had to last a few hours.

author: mzzj
author_rank: Super Contributor
timestamp: April 01, 2024, 08:00:05 pm
content: With the provided information: Absolutely maybe!
Synchronous rectifier driver chip is very poor? - Page 1
Forum section: electronics / general

author: Faringdon
author_rank: Super Contributor
timestamp: March 31, 2024, 06:13:48 pm
content: Hi,The attached shows a Full Bridge with Synchronous Rectifiers. (LTspice and PNG)48Vin, 12Vout 200Wout, 117kHz.At 3ms in the LTspice sim, the load gets suddenly switched out from full load to no load. As the inductor current falls,it then reverses, -whilst it is in reverse in the synchronous FET, the synch FET is then turned OFF. This is "breaking aninductive current"...not just some little stray inductive current, but the inductive current in the power inductor!These overvoltages are so high that they overvoltage the synch FETs and their paralleled diodes.It may be said that the LTC3901 offers reverse current sensing in the synchronous FETs, and that it would switch them offbefore this current got too high. However, this is not acceptable. The signal from any sense resistor would be very small, anddrowned in noise at low levels of reversing current.In any case, by the time the power inductor current has actually gone into reverse, its way too late to switch off the sync rect FETs.May i ask Why has this chip (LTC3901) been manufactured?It is unsuitable for purpose. It doesnt even have a shutdown pinso that the synch rects can be turned off as the inductor current falls towards zero.

author: f4eru
author_rank: Super Contributor
timestamp: April 01, 2024, 03:21:07 pm
content: 'Fool Bridge Rectum Fryer
SMPS Controller datasheets and imposible to find transformers etc - Page 1
Forum section: electronics / general

author: dch53
author_rank: Contributor
timestamp: April 09, 2024, 01:57:55 am
content: Most controller and evaluation boards include a BOM. I never find magnetic component identification information any use at all.Take the MPS MPX2002/3 flyback controller datasheet and evaluation boards for example. Various transformers are- RM10 FX0575- RM10 ZYD FX0606- ZYD ATQ24 FX0633-1- ARK ATQ2718 FX0652RM10 is a core size. Maybe ATQ24 and ATQ2718.Searching for any of these transformer cores is pointless. Either nothing is returned or the only instance is a link to the datasheet itself. It's the same with resonant controller evaluation boards.Same problem with chokes and inductors.I get that the evaluation boards are made in China and ZYD and ARK are probably Chinese companies. Also, that this wouldn't be a problem for those designing power supplies as a profession. I'm not.Can anyone help me identify these transformer cores please?Thanks!

author: TimNJ
author_rank: Super Contributor
timestamp: April 09, 2024, 02:34:17 am
content: You just want to know what cores ATQ24 and ATQ27 refer to?http://www.chn-sunshine.com/cpzxFN/info_183_itemid_351.htmlhttp://www.china-sanlin.com/en/product/product-catalogue-230.htmlhttp://m.acore-ferrite.com/en/displayproduct.html?id=2649005206783468I have used the ATQ style and they are generally well optimized, and good especially for use in the vertical orientation. There are many variants, and not much standardization so YMMV for different sizes/geometries of so-called ATQ. If you don’t have a specific requirement for these cores, and you don’t have a big space constraint, and don’t plan to manufacture in China, the RMs, PQs, POTs, etc can still do very well. By the way, EQ and ATQ seem to be sort of similar, except ATQ tends to have an oblong/ovular center-post cross section

author: mtwieg
author_rank: Frequent Contributor
timestamp: April 09, 2024, 01:06:21 pm
content: In the past I've contacted the vendor for the dev board (NXP and Linear Tech, off the top of my head) and they were often happy to send me their drawing of the transformer, which you could send to any CM if you wanted to duplicate it. Not sure if all companies do this, however.

author: f4eru
author_rank: Super Contributor
timestamp: April 10, 2024, 09:29:39 pm
content: Devboards are often an EMC nightmare.Take those design with a grain of salt.

author: dch53
author_rank: Contributor
timestamp: April 11, 2024, 07:36:19 am
content: Thanks very much for the replies!
220vac 1P breaker on 110vac Circuit  - Page 1
Forum section: electronics / general

author: TAS2
author_rank: Newbie
timestamp: March 21, 2024, 09:23:07 pm
content: Hey. I am working on a project and planning to incorporate power and electronics using DIN rail. I ordered some 1P breakers and then later noticed they’re marked 220vac. I’m in North America and everything except certain equipment run on 110vac.Will using the 220vac breakers on 110vac work properly?

author: f4eru
author_rank: Super Contributor
timestamp: March 22, 2024, 06:49:41 am
content: Yes, absolutely they will work no problem, but one thing to keep in mind:Those breakers are not certified/approved for your country, so don't count on them as far as anything involving legal issues are concerned (insurance, responsibility, etc....)As long as your supply has a properly approved breaker upstream protecting the whole circuit you should be fine.

author: NiHaoMike
author_rank: Super Contributor
timestamp: March 27, 2024, 12:14:49 pm
content: If they have active protection features like GFCI/RCD or AFCI, those features probably won't work reliably if at all. But the overcurrent part will work just fine.
Modifying a BP2861 (PAM2861?) module to produce lower current seems to break it? - Page 1
Forum section: electronics / general

author: badrequest400
author_rank: Contributor
timestamp: March 22, 2024, 10:39:31 pm
content: I wanted to modify a BP2861-based module I bought so it would run my mains-powered LED light fixture much dimmer than the designers intended but it didn't work. I think the BP2861 is meant to work approximately the same way as a PAM2861. I can't find a datasheet for BP2861 but I identified what I think is the I(sense) resistor which was 0.82 ohms on my modules. This was giving a current of 167 mA from each module before I messed with them.I desoldered the 0.82 ohms resistor and replaced with a 10 ohm resistor, thinking I'd just get a much lower current but it seems like I broke the module (going back to the 0.82 ohm resistor did not restore the module to normal function). The light fixture is unaffected (it still works when powered via an unmodified module). Is that what you would expect to happen? For anyone who understands how the PAM2861/BP2861 functions, would you expect there to be a lower limit to much current it can deliver before something breaks or should there be no lower limit? Thanks.
Connecting wires from Inlet to Meanwell PSU  - Page 1
Forum section: electronics / general

author: eeguy
author_rank: Regular Contributor
timestamp: March 21, 2024, 06:20:56 pm
content: Hello,Could you please let me know which ports on the Meanwell PSU should the yellow, red and blue wires be connected to?https://imgur.com/a/ZcedvLVhttps://imgur.com/a/5fzQInh

author: sm_94
author_rank: Newbie
timestamp: March 21, 2024, 06:58:49 pm
content: A(yellow) -> earth groundB(red) -> LC(blue) -> N

author: eeguy
author_rank: Regular Contributor
timestamp: March 21, 2024, 10:47:57 pm
content: What do L and N mean?

author: MarkF
author_rank: Super Contributor
timestamp: March 21, 2024, 10:52:59 pm
content: L == LineN == NeutralIn the USA, 'Line' is 120VAC and 'Neutral' is 0VAC.

author: Someone
author_rank: Super Contributor
timestamp: March 21, 2024, 10:55:57 pm
content: Quote from: eeguy on March 21, 2024, 10:47:57 pmMeans you shouldn't be messing with mains power.
A stretch of road in downtown Detroit can now wirelessly charge electric vehicle - Page 1
Forum section: electronics / general

author: boB
author_rank: Frequent Contributor
timestamp: March 17, 2024, 06:10:29 pm
content: Sort of like solar freakin' roadways but, different. We'll see...https://www.ibew.org/media-center/Articles/24Daily/2403/240212_EVChargingRoad/fbclid/IwAR2EgkQprSnB9CE2o2SdZoDTF8D-FnDjbQQQuf5dOxxZHergG2jsllbkkDgProbably fairly inefficient if the vehicle is far above the coil.

author: shapirus
author_rank: Super Contributor
timestamp: March 17, 2024, 06:59:32 pm
content: I have a great idea: there can be powered wires hanging above the roads, and cars would have spring-loaded rods on the top that could make contact with those wires. This way they could charge while moving with the highest efficiency possible, and that would be much cheaper than anything wireless.Has anyone patented it yet?

author: jbb
author_rank: Super Contributor
timestamp: March 17, 2024, 09:53:16 pm
content: Ooh, ooh! That’s a great idea; an electric vehicle which doesn’t need a big expensive battery. We could put some metal rails in the road for the ground return!In fact, rolling resistance of a steel wheel on a steel rail is much better than rubber tyre on asphalt road. So how about we take a bus and run it along the rails?Ideally, it would be nice to separate such a means of transport from the regular roading network. With such a separation we could schedule regular services and avoid traffic jams from overloaded roads.

author: jbb
author_rank: Super Contributor
timestamp: March 17, 2024, 09:55:29 pm
content: Good news / bad news. I did some research and found out that this ‘bus on steel rails’ business was developed in the 19th century.Good news: we know it works!Bad news: no juicy patents for us.

author: radiolistener
author_rank: Super Contributor
timestamp: March 19, 2024, 07:47:07 am
content: If you want to charge your electric car on the way, you can use petroleum or diesel AC alternator.

author: tegan
author_rank: Newbie
timestamp: March 19, 2024, 01:46:00 pm
content: i do know this is a joke/meme but charging a tesla with a generator is more fuel efficient then driving the wheel directly im pretty sure since it runs it effectively curve without stop and start.

author: shapirus
author_rank: Super Contributor
timestamp: March 19, 2024, 01:58:29 pm
content: Quote from: tegan on March 19, 2024, 01:46:00 pmYes, also because you can run the engine at its highest-efficiency RPM, and there is much less mechanical losses. Electromechanical drivetrain is widely used in larger vehicles: locomotives, quarry trucks etc.

author: nctnico
author_rank: Super Contributor
timestamp: March 19, 2024, 07:46:28 pm
content: Quote from: shapirus on March 19, 2024, 01:58:29 pmThat is not done for efficiency as the conversion losses are quite high. Torque to pull away is easier to control with an electric motor. With a direct drive system, you'd need a clutch and for a train that clutch will need to be huge.
A Boost PFC stage will do fine with a 300VDC input? - Page 1
Forum section: electronics / general

author: Faringdon
author_rank: Super Contributor
timestamp: March 17, 2024, 11:34:34 pm
content: Hi,A Boost PFC stage will do fine with a 300VDC input.Whether average current mode, "constant on time mode", or BCM PFC.LTspice says it will be fine.Would you agree with this? Our contractor says no , but we think it will be fine.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: March 18, 2024, 12:04:55 am
content: Many are fine. If the control depends on pulsating mains voltage, or other assumptions about the waveform, that would be a bit of a problem. Some have an integrated X-cap discharge, which is triggered by lack of pulsation; these blow up on DC input.Tim

author: Faringdon
author_rank: Super Contributor
timestamp: March 19, 2024, 12:33:18 pm
content: Thanks for pointing out those cases.As we know, in a Boost PFC, the outer voltage loop eventually wins out....no matter if vin is half sine or flat DC.Even the following PFC chip will work with flat DC Input og +300V...https://www.infineon.com/dgdl/Infineon-ApplicationNote_EVALPFC-300W-ICE3PCS01G-AN-v02_00-EN.pdf?fileId=db3a30433580b37101358a4e00996b86If you give a flat continuous DC input, then you only use half of the rectifier bridge, so in theory it could overheat. However, bridge rectifiers are as tough as old boots, and the standard Si diodes go lowerin Vf as their temp increases..so they self cool.
how to charge a S4P2 LiFePo4 battery array - Page 1
Forum section: electronics / general

author: tegan
author_rank: Newbie
timestamp: March 19, 2024, 01:30:55 pm
content: im build myself an Ebike and ive been putting together a buget for build the packi wanna go with LiFePo4 since they long life and cycel well and because the bike is a 3 wheel one.looking over the kits i can buy im looking at the 1000 watt ones as I'm not in it for the speed but for the towing capacity since ive got a trailer to go with it.there also a 500 watt kit as well.the iusse is is the 1000 watt draw 22 amps at 48 volts while the 500 draws over 10 amp the cells im looking at only take 10 amps max draw so i need put them in a S4P2 configurationthe other option is to put a volage divider on the throttle so that i can max the power above 10 amps the store owner said it an Amps based control vs speed based control so doing think i think will work.the next iusse is how to charge the dang thingso if I'm doing a S4P1 or S4p2 configuration im not fully sure how to get the array all in worksit has a BMS in the module and it says you can put them in a 4s configuration.https://www.altronics.com.au/p/sl4551a-powerhouse-12v-20ah-lithium-lifepo4-battery/this is the modul im looking into if was doing the S4P2 configuration ill be using the 8ah cellsi dont see any procedures for 4s configurations
Feeding 2 BMSs from one DC input - Page 1
Forum section: electronics / general

author: gattu marrudu
author_rank: Newbie
timestamp: March 18, 2024, 01:58:40 am
content: Hi there,I am building a battery-powered circuit with a class D amplifier and a single-board computer serving as a music source.The amp takes anywhere from 12-24V and the SBC is a Raspberry Pi Zero with a 5V input.I have a 6x18650 battery pack with a 6S BMS attached, fed by a 22V switching transformer, and a buck/boost module to regulate the input to 5V for the SBC.Now, I found the hard way that connecting both the amp and the SBC to the same DC input results in terrible noise from the SBC current draw, as well as power-cycling the SBC when I power up the amp.I have thought about a few solutions:1. Using some combination of capacitors as noise filters. I tried a 10nF ceramic cap across the SBC input but that didn't change anything2. Add a decoupling LC filter along with a bypass cap. I'd like to understand better how this works and how to calculate the component values. Any suggestions?3. Using two power sources. I built a separate 3.7V battery pack with BMS for the SBC, using the same switching power supply to recharge both packs (otherwise my setup would be much less portable). But I am not sure how the layout would look like. I can't put the BMS after the DC-DC converter as it would make the converter fail (because it's a power supply as well as a load? Would a diode work?)I have only basic knowledge of electronics and I'm missing some key concepts, but I feel like this should work one way or another. Any hints would be highly appreciated.Thanks.gm

author: gattu marrudu
author_rank: Newbie
timestamp: March 18, 2024, 03:29:30 pm
content: Update: adding a diode between the DC-DC converter and the BMS (in the solution with a separate battery pack) worked and got rid of the SBC losing power and rebooting when I turn on the amp, but not of the noise problem.Next I'm trying the setup in the attached image.This uses a 7.4V battery pack instead of a 3.7V one, and two DC-DC converters (one to get from 22 to 7.4 V to charge the batteries, the other one to get to 5V to power the SBC). I ordered a 2S BMS. Any hints?Thanks.gm
Low output frequency from inverter - EPever IPower - Page 1
Forum section: electronics / general

author: Miyuki
author_rank: Frequent Contributor
timestamp: March 16, 2024, 03:53:42 pm
content: Hello,I'm using EPever IPower 5kW inverter to supply the majority of the house consumption, everything is fine, except the clocks use mains frequency to runI have no idea why must new expensive kitchen appliances use mains frequency clocksIt runs about -0.15% under, what it is within inverter specs, but causes the clock to show total nonsense after a few days.I wonder if somebody tried to solve this issue with this or similar inverter.

author: fourtytwo42
author_rank: Super Contributor
timestamp: March 16, 2024, 06:23:53 pm
content: You would have thought with all those fancy menu's in there that there would be a frequency fine tune, poor design and or little experience of real world, common feature of design these days

author: Marco
author_rank: Super Contributor
timestamp: March 16, 2024, 07:53:32 pm
content: No need to finetune, they do that in the factory if you buy a crystal. Seems they both saved a couple cents by running on a RC oscillator.Since it's likely the microcontroller internal oscillator, there is probably not much you can do unless you're really lucky and it's connected to an external pin where you can force it.

author: jbb
author_rank: Super Contributor
timestamp: March 17, 2024, 09:59:51 pm
content: Maybe look for ‘droop’, ‘islanding’ or ‘paralleling’ settings?

author: Miyuki
author_rank: Frequent Contributor
timestamp: March 18, 2024, 11:29:23 am
content: It has no such public setting or config register and their tech support just told me that it cannot be fine tuned
Thermal Protection of ORING circuit - Page 1
Forum section: electronics / general

author: Magnethicc
author_rank: Contributor
timestamp: March 25, 2024, 09:42:15 am
content: Hello everyone,I have a 57A ORING circuit (using LTC4357 and 3xD2PAK MOSFETs in parallel).We noticed that during an abnormal situation where there may be a short between the gate and the source of one of the MOSFETs that the ORING controller no longer works and the entire current flows through the body diodes of the MOSFETs causing them to overheat in a smoky fashion.Do you have any ideas on how to protect thermally in case of MOSFETs not working?

author: SeanB
author_rank: Super Contributor
timestamp: March 25, 2024, 10:34:18 am
content: Littelfuse LR range polyswitches in parallel, held on top of the MOSFETS should help, as they also will trip when hot, and are rated for 100A breaking current. You would need 6 13A devices in parallel.https://www.littelfuse.com/media?resourcetype=datasheets&itemid=d79bb3c2-7bcd-4a2d-8e2d-8a68259bd728&filename=littelfuse-ptc-battery-strap-lr4-datasheetWhen they get hot trip current decreases, so the hot transistor will result in one tripping, followed by the others in very short order.

author: f4eru
author_rank: Super Contributor
timestamp: March 25, 2024, 10:02:16 pm
content: partial circuit may be helpful.
US Split-Phase to EU Heat Pump Not Working - Page 1
Forum section: electronics / general

author: quantum
author_rank: Newbie
timestamp: March 08, 2024, 04:01:33 pm
content: Hi, I've ordered and receivedan advanced heat pump from Jiangsu Micoein Red China. It is a full inverter-driven air-to-Water heat pump, IOW the fan motor, compressor, etc, are all PWM driven. The power supply takes in line voltage and immediately converts it to DC for moderation by the controller.It is designed for the EU market which of course has 230v on one line, neutral on another, and ground on the third. I am in the US where of course we have split-phase 240v with ground, which I thought in theory should power this machine just fine. Unfortunately it does not. I turn on the outdoor cutoff switch, and nothing. Nothing on the indoor display as well.I've tested the voltage to it and indeed it is 240vAC. I've been without house heat through two Winters and sure would like to get this thing running. I've considered buying anEU-to-US isolation transformer, but would have to run it backwards which seems dicey, and I question whether it would help.Engineering manual.

author: nctnico
author_rank: Super Contributor
timestamp: March 08, 2024, 04:27:51 pm
content: Get a multimeter (a CAT rated one for use on mains) and check the voltages. Maybe you need to turn on a switch somewhere else in the machine or open up the valves so all the pressure switches are activated. As line & neutral may be reversed at will, the unit should work on a split phase system as well. IOW: Read the installation manual carefully and follow the installation procedure step-by-step.

author: ZigmundRat
author_rank: Regular Contributor
timestamp: March 08, 2024, 04:34:46 pm
content: If for EU market, is a 50Hz unit. That could be an issue.Other than that, i would start with checking all the inputs and outputs for AP4 to start. That's the power supply that feeds the motherboard.In addition, other boards (AP2, AP5, the compressor drive board and fan driver e.g.) also take 230v, so may be sensitive to 50Hz vs 60 Hz issues.

author: quantum
author_rank: Newbie
timestamp: March 10, 2024, 06:29:26 pm
content: Good leads, I'll work on it. Thank you.