hybridfree/eevblog-posts huggingface dataset:
Looking for USB-PD 3.1 Sink IC - Page 1
Forum section: electronics / general

author: centylab
author_rank: Newbie
timestamp: January 17, 2024, 08:18:46 pm
content: I started to see all of the wall chargers that can provide 140W with USB-C PD 3.1. I have been looking for an IC that can just easily act as SINK that can handle this PD 3.1 protocol but have not had much luck. I found the HUSB238A by Hyentek that said to support PD 3.1 but offers no retail purchase unless to go to the only posting with no review on Aliexpress. People have been saying the FUSB302B can act as the middleman to request 28V but this IC is considered hard to use.Anyone has had any luck finding a PD3.1 SINK IC that can be controlled or programmed via uC?Thank you,

author: elbucki
author_rank: Newbie
timestamp: January 25, 2024, 10:44:27 pm
content: Look at the Pinecil firmware, they do EPR with the FUSB302Bhttps://github.com/Ralim/IronOS. Also, check out the PMG1-S3 from Infineon, they have examples on github for EPR using Modus Toolbox and the PMG1-S3.

author: brumbarchris
author_rank: Regular Contributor
timestamp: February 02, 2024, 06:28:49 am
content: What about this one?https://www.ti.com/product/TPS25730Dors not even need a micro to control it, works standalone.Br,Cristian

author: Tuege
author_rank: Newbie
timestamp: March 17, 2024, 12:13:33 pm
content: That's a PD3.0 deviceIt only allows up to 20V@5A

author: Elec_Jonny
author_rank: Newbie
timestamp: September 28, 2024, 01:15:45 pm
content: You can buy the HUSB238A from LCSC. The only problem i faced is that i cant find information about the I2C Interface specs. Does anyone have any clue about where to find the information abour registers and Timings for config?

author: voltsandjolts
author_rank: Unknown
timestamp: September 28, 2024, 02:55:32 pm
content: There are quite a few results from google using search query "HUSB238A site:github.com"
DCS Battery (Australia) Lawsuit against youtuber - Page 1
Forum section: electronics / general

author: midnightvisions
author_rank: Contributor
timestamp: August 19, 2024, 05:54:30 am
content: Dave can you have a review of this Australian battery company DCS lawsuit against a youtuber.(not commenting on the lawsuit, but the battery and testing methods)(MOST RECENT) Independent review of DCS battery-----------DCS is suing this youtube reviewer for a bad reviewLawsuit for defamation info;Lawsuit updateLawsuit update 1Lawsuit update 2Lawsuit update 3Thanks

author: Cablenone
author_rank: Newbie
timestamp: August 20, 2024, 01:24:41 am
content: Somebody reported already Will Prowse for doing his dcs battery Review. Probably DCS

author: fzabkar
author_rank: Super Contributor
timestamp: September 29, 2024, 06:37:07 am
content: See page 28 of this document:https://storage.googleapis.com/itp-renewables-website/documents/Battlab_Report_12_Final.pdfA DCS PV 10.0 LiFePO4 battery stands out as being the worst performer out of 8 tested products in the Phase 3 Capacity Test Results. The battery's state of health was already below 80% at 800 cycles.
Solax X3 inverters IE06 error - Page 1
Forum section: electronics / general

author: aurelleostean
author_rank: Contributor
timestamp: September 20, 2024, 05:11:46 pm
content: Hello friends! I have an issue with an Solax X3-hybrid-12.0-D-G4 12kW three phase inverter, with 17kW of battery in EPS mode offgrid all the time. This inverter is a hybrid inverter and has a EPS Emergency power supply port so when the grid fails or the sistem is permanently isolated from the grid, the critical loads can operate from the battery.I have some loads that trigger the inverter to report error IE06, cut the output power and restart after a couple of seconds. The devices that trigger the restart are a hair dryer, expresso machine, blender, dishwashing machine, only these I got to test so far. Has anyone experienced this type of situations and what are the solutions adopted? I found that increasing the load on the EPS port reduces the error count. The problem with this solution is that it drains the power faster from the battery, and in the offgrid situation this is not ideal. Any sigestions please let me know. Thank you!
Can an ESC be used as an active 3 phase recifier? - Page 1
Forum section: electronics / general

author: cedric!
author_rank: Contributor
timestamp: September 07, 2024, 04:20:13 pm
content: I've seen people online creating generators from BLDC motors . Usually they take a BLDC motor, connect the 3 phase output to a 3-phase 6-diode rectifier, and then use a buck/boost converter to charge their battery.This looks like a waste to me, as then there are always 2 diodes in series with the coils in de BLDC motor.Is it possible to use an electronic speed controller to rectify the 3-phase waves from a motor? Is it possible to use the regenerative braking feature for this?Can ESC's be programmed to let the BLDC motor run freely until a certain optimal speed is reached, and then progressively brake harder, to maintain that speed? With this setup, the BLDC motor can be connected to a diesel engine, that is then maintain it's optimal speed, so it converts the most chemical energy into movement energy, and then into electrical energy for the battery.It looks like VESC board  is capable of regenerative braking. "DHT Project: Make a Powerful Generator from a Dead BLDC Motor"https://trampaboards.com/vesc-6-mkvi--trampa-gives-you-maximum-power-p-34848.html

author: Siwastaja
author_rank: Super Contributor
timestamp: September 07, 2024, 04:58:02 pm
content: The answer is YES, and what's even better, you can even boost the voltage, with the motor inductance and the 6-switch bridge itself acting as the boost converter. No extra components needed. This is bog standard "regenerative braking". All that is needed is either understanding an existing control firmware, or creating one's own. In this case, you would want to prevent driving the motor, only regenerate.This also allows you to add a torque limit to accurately control the battery charging current instead of always going "full blast", making the motor easier to rotate.
Quick question, 12x 85mAh LiPo cells with PCMs charging in parallel ok? - Page 1
Forum section: electronics / general

author: Psi
author_rank: Super Contributor
timestamp: September 09, 2024, 10:50:42 pm
content: Basically as the topic says, Are there any legitimate concerns connection 12x 85mAh cells that each have a PCM all in parallel together and then charging and discharging them as if they're one battery?Obviously this is quite a hacky solution, but are there any legitimate reasons why doing this is unsafe even for a hacky solution?The only issue i could come up with was if, for some reason, all but one of the PCMs disconnected then the charge current would be going into a single cell. Which might be too much charge current for one cell.Thanks.

author: Siwastaja
author_rank: Super Contributor
timestamp: September 11, 2024, 02:29:29 pm
content: Definitely won't recommend doing it. Unless the "PCM" is specifically designed for this, but usually the cheap stuff implements quite crude and unreliable overcurrent protections. The protection modules are not actually current limiters (as like in constant current mode), but more like electronic fuses that react to serious overcurrent events after they already happened. You would need some logic to first equalize the voltages before parallel connection. Permanent bare cell parallel connections are easiest way to prevent these currents for good.

author: Psi
author_rank: Super Contributor
timestamp: September 12, 2024, 08:41:59 am
content: Thankfully the reason I was thinking about doing this is no longer needed.
Capacitive Dropper Flicker - Page 1
Forum section: electronics / general

author: johnywhy
author_rank: Contributor
timestamp: October 09, 2024, 03:30:41 am
content: I read that a capacitive dropper supply, like those found in some LED light bulbs, has issues like inconsistent brightness, flickering, and voltage fluctuations.Is the following correct?The flicker isn't caused by the cap. Fluctuations on the secondary are due to all the following:fluctuations of the primary (mains)fluctuations in the loadmains frequencyIn other words, it's a non-regulated output.Capacitive Dropper Supply.jpg

author: mikerj
author_rank: Super Contributor
timestamp: October 09, 2024, 08:18:39 am
content: Some people are sensitive to the LEDs turning on and off at a 50 or 60 HZ rate, so they would see a constant flicker. Another issue is that unlike incandescent or compact florescent lamps, this circuit will respond instantly to brief changes in the incoming supply voltage e.g. caused by a heavy load switching on and off. The more expensive LED lamps that use a switching regulator rather than capacitive dropper don't tend to have this problem.

author: Seekonk
author_rank: Super Contributor
timestamp: October 09, 2024, 01:16:04 pm
content: In LED lights with long LED strings, these LED form a zener. I use LED in circuits as a voltage reference and voltage lever dropper. They work quite nice. Small voltage changes on the mains become exaggerated when the LED string voltage is subtracted. And of course any high frequency passes thru cap easier.

author: Wolfram
author_rank: Frequent Contributor
timestamp: October 09, 2024, 03:19:30 pm
content: The flicker is a consequence of not having any smoothing capacitors. It's not inherent to capacitive droppers.

author: tooki
author_rank: Super Contributor
timestamp: October 09, 2024, 06:35:21 pm
content: Quote from: johnywhy on October 09, 2024, 03:30:41 amPrimary ≠ mains.Primary = the input sideof a transformer. The source of that input voltage or signal is irrelevant. It can be mains, it can be a battery-powered oscillator, it can be an analog audio signal, it can be an Ethernet data line.In this case, there is no transformer at all, so you don’t have a primary or secondary.
Can the BQ2085+BQ29311 solution be used to manage 2 cell of lithium batteries? - Page 1
Forum section: electronics / general

author: daisizhou
author_rank: Super Contributor
timestamp: August 23, 2024, 11:22:54 pm
content: I got a lithium battery management control board.It is a 3-cell lithium battery pack, the chip is BQ2085+BQ29311,I would like to ask if it can be used in a 2-cell lithium battery pack?If so how can I connect

author: squadchannel
author_rank: Frequent Contributor
timestamp: August 24, 2024, 12:51:44 am
content: It would be possible to connect it to the bq2085, change the firmware, and change the circuit as well.but, DONT DO IT, it is easier to design a new BMS.Modern battery packs are detected as abnormal when a cell is disconnected, and no voltage is output when the cell is reconnected. Naturally, recharging is not possible.Cells cannot be replaced. Throw them away.

author: daisizhou
author_rank: Super Contributor
timestamp: August 24, 2024, 01:29:52 am
content: OK .thanks
Charger for lead acid battery. - Page 1
Forum section: electronics / general

author: Thommyy
author_rank: Newbie
timestamp: August 18, 2024, 09:04:30 pm
content: I need to make a charger for lead acid battery which will be controlled by MCU. The batteries are connected in series of 6pcs, that means 72VThis is a UPS backup power supply.Can you recommend me some power supply where the output voltage and current could be controlled externally, for example PWM or via some communication.The input voltage is max: 95VCurrent max: 3AI know that Analog Devices has different circuits of ready chargers but I haven't discovered any that would be close to my parameters.Thank you for your answers and help.

author: mtwieg
author_rank: Frequent Contributor
timestamp: August 20, 2024, 11:48:51 am
content: A few options:1. Do everything, including voltage sensing, current sensing, and PWM generation with the MCU. The charging algorithm implemented entirely in firmware. The firmware will also be responsible for the high speed voltage and current control loops, requiring a much greater firmware effort.2. Use a generic PWM controller IC (preferably one which has average current-mode control). The MCU doesn't have to manage the high speed voltage and current control loops, but can adjust their setpoints in order to allow it to implement the charging algorithm.3. Find a more specialized PWM controller IC which does some/all of the charging algorithm.One part maybe worth looking at is the UC2909. It's a simple pwm controller but it also can implement a simple three-stage charging algorithm. It will need some external circuitry to interface it to the high voltage power path. I'm not aware of any suitable PbA charger ICs rated for such high voltages (LTC4013 is the closest I'm aware of at 60V).Hard to give more specific guidance without knowing about your background (power electronics and MCU coding). If you're new to power electronics I would strongly recommend starting off at 12V and then scaling up only after mastering that.
Strange behavior today w/ TWO 200W panels wired in parallel - Page 1
Forum section: electronics / general

author: TT_Vert
author_rank: Regular Contributor
timestamp: July 26, 2024, 04:55:06 pm
content: This is on my RV.I'm just looking for opinions. The problem is resolved but I'm trying to wrap my head about this as the behavior doesn't make sense. I noticed in my solar app that I was only seeing about 12V fed into my MPPT controller and no current into the batteries. Battery SOC was near 40% so i knew something was wrong. I have a triron 3210N MPPT and two 200W panels wired in parallel so I should see about 22V and at least SOME current today. I checked my other array for my shed and it was putting out power so i knew I should be seeing something.I took my DVOM and noticed that when I turned OFF the breaker between the panels and the charge controller I would see 24V from the panels but the second I turned the solar feed back on to the MPPT it dropped to 12V and still no current. Turns out one of my two panels' positive plugs was loose. But given my panels are wired in parallel, shouldn't one panel have still been providing current and 22ish V? Why would this occur when it was loaded only?Thanks much,Dave

author: thm_w
author_rank: Super Contributor
timestamp: July 26, 2024, 09:24:18 pm
content: Doesn't really make sense unless one panel is bad or was very shaded.Or the loose connection was not where you thought and affected both panels.Do a short circuit current comparison between the two maybe?

author: TT_Vert
author_rank: Regular Contributor
timestamp: July 27, 2024, 03:45:26 pm
content: Neither panel was shaded, and the loose connection was certainly at that positive wye into the MPPT controller. It was loose and as soon as i clicked it back in I was back in business. I saw 300W on my 400W of panels right away. It just doesn't make sense to me.Dave

author: TT_Vert
author_rank: Regular Contributor
timestamp: July 31, 2024, 02:45:05 am
content: Anyone else have any opinion?

author: TT_Vert
author_rank: Regular Contributor
timestamp: August 07, 2024, 04:41:19 pm
content: One last chance at getting input from the experts.Dave

author: Poroit
author_rank: Frequent Contributor
timestamp: August 09, 2024, 03:46:32 am
content: I suggest it was just a glitch in your Solar App due to the type of fault.Imagine the scenario that the controller was trying to deal with.A loose positive terminal with the available current capacity changing every time your RV hit a bump in the road.I doubt the designers ever allowed for that type of scenario.

author: TT_Vert
author_rank: Regular Contributor
timestamp: August 20, 2024, 05:33:21 pm
content: I don't understand what scenario the MPPT was dealing with that's just it. The panels were wired in parallel so even if one didn't have one lead connected I should have been getting 24V and a max of 200 W from the one connected panel i'd assume. That's where my confusion comes in.Dave
I got a mystery A123 battery pack for free... - Page 1
Forum section: electronics / general

author: NiHaoMike
author_rank: Super Contributor
timestamp: August 19, 2024, 02:51:21 am
content: Someone on a Facebook solar group (who happens to be fairly close to my area) gave away a mystery A123 battery pack since he couldn't figure out how to repurpose it. He did mention that all the modules have the normal voltage (which I later confirmed was in fact the case), so I thought it was well worth getting. 188V and 25Ah is 4.7kWh, quite substantial and worth a lot if it works.The pack is made up of 7x 8S modules that separate easily. Each one has its own BMS board although I'm not sure if the board can be easily reused. I plan to build my own BMS based on a string of RISC-V microcontrollers but reusing the boards would be much less effort if practical. Note that unlike a standalone BMS, those boards do not interrupt the current flow in a fault condition. That part is handled in the control system which (for image size limits) will be in the next post.

author: NiHaoMike
author_rank: Super Contributor
timestamp: August 19, 2024, 03:03:49 am
content: There's a CR0303 PLC taking care of the central control. No idea if the program is protected against readout.There's also a built in charger apparently based around a modified motor inverter design. A complex arrangement of HVDC relays is used to switch between boost and buck mode for 120V and 240V mains input. Surprisingly, there's no PFC, which means it would only be able to get the about 70% of the maximum charge rate possible from the mains circuit. Maybe they tried to implement it but ran into issues (EMI?) and just decided to do a quick respin of the rectifier board without PFC and release it to market.I'm not sure what the original application is. 4.7kWh is not much for a full sized car (unless this isn't the only pack and there are more elsewhere), so I'm guessing something like an electric riding mower, golf cart, or small tractor.
MOVED: One of the most interesting paragraphs I have ever read - Page 1
Forum section: electronics / general

author: DejanC
author_rank: Regular Contributor
timestamp: August 04, 2024, 02:58:23 pm
content: This topic has been moved toProjects, Designs, and Technical Stuff.https://www.eevblog.com/forum/index.php?topic=435903.0
Lab power supply components - Page 1
Forum section: electronics / general

author: joniengr081
author_rank: Regular Contributor
timestamp: July 29, 2024, 11:03:07 am
content: I am wondering if it is possible to get to know the schematic of standard lab power supply. How do they adjust the output voltage when we change the knob voltage and how the sense circuit works at component level.

author: pqass
author_rank: Super Contributor
timestamp: July 29, 2024, 12:04:04 pm
content: Seehereandhere.

author: jonpaul
author_rank: Super Contributor
timestamp: July 29, 2024, 04:44:08 pm
content: see excellent Hewlett Packard and Lambda 1970s..1990s serv manuals for the type/power/outputs similar.We use the dual and triple HP lab suppliews 6205B and 6237B.Jon
Small LiPo Supplier Suggestions - Page 1
Forum section: electronics / general

author: technically_not
author_rank: Newbie
timestamp: July 29, 2024, 12:27:21 pm
content: I'm developing a small wearable project for a client that expects to produce the low thousands each year. The product needs to contain a small pouch-style LiPo battery, in the order of 200mAh or so, and it may need to be a custom size or at least a custom connection.This must be a fairly common requirement, but I have no idea where to source these and my google-fu has failed me thus far.Ideally I'd like a UK-based company that we can deal with, but I'm also open to considering a Chinese supplier as long as I've got a recommendation.Any suggestions/experience/recommendations?
Grid to inverter switching - Page 1
Forum section: electronics / general

author: Qrdi86
author_rank: Newbie
timestamp: July 27, 2024, 11:16:08 am
content: Hello, how cheap hybrid inverters connecting grid and battery power? Like this herehttps://photos.app.goo.gl/HZ1CsLhYzYt16wUg6or there is another time delay relay inside? Does anyone have the schematic part of the easun inverter, where switching grid to battery? Would the solution as shown in my diagram be dangerous for the inverter? I would like to use this relayhttps://vi.aliexpress.com/item/1005006200836487.html?spm=a2g0o.productlist.main.21.49036095R3AgoW&algo_pvid=fcdd13f7-2296-4274-8917-e5b3b00b90e7&algo_exp_id=fcdd13f7-2296-4274-8917-e5b3b00b90e7-10&pdp_npi=4%40dis%21EUR%210.68%210.44%21%21%210.72%210.47%21%4021039fae17220786867413441e756e%2112000036242958450%21sea%21EE%212651531538%21&curPageLogUid=ZxR8uGVxENZd&utparam-url=scene%3Asearch%7Cquery_from%3A

author: Andy Chee
author_rank: Super Contributor
timestamp: July 27, 2024, 02:25:16 pm
content: The basic device you are looking for is called an automatic transfer switch:

author: Qrdi86
author_rank: Newbie
timestamp: July 28, 2024, 10:15:06 am
content: I would like to see how this circuit is solved in a hybrid inverter. There is switching time 10 ms. I have seen in youtube videos that there are 3 or 4 relays like the one in my first post link, but how are they connected there?E:, in the fifth minute of this video, you can see these relays, there are 2 of them there(black), how are they connected to switch the mains voltage?
Are there lithium battery management chips that replace lead-acid batteries? - Page 1
Forum section: electronics / general

author: daisizhou
author_rank: Super Contributor
timestamp: July 25, 2024, 10:27:35 am
content: I have a Yamaha motorcycle,It uses 12v lead acid battery,Usually this kind of lead-acid battery has a service life of only 2-3 years.I've seen a lot of people use lithium batteries instead, but it looks like they're amateur-made and not legitimate products.The most common solution I see is the lithium iron phosphate battery solution,But they hardly use battery management chips, some even simply connect positive and negative。I was wondering if there are any specialized chips suitable for lithium battery management used on motorcycles?Because the starting current is usually 90A-120A，Conventional lithium batteries will disconnect the battery cells after they are fully charged, but they cannot be disconnected on motorcycles because lead-acid batteries have trickle charging. In other words, a lead-acid battery is similar to a "load resistor" after it is fully charged.

author: thm_w
author_rank: Super Contributor
timestamp: July 26, 2024, 12:46:54 am
content: QuoteMost 12V Lifepo packs have a BMS inside. It would be very odd not to.Here is one example:https://www.amazon.ca/MOSEWORTH-LiFePO4-MOS7B-4-Motorcycle-Kawasaki/dp/B093BZYWNKYou can also get lithium which also has BMS, as seen in the photos, not cheap but it is quality:https://no.co/products/lithium/powersportQuoteNo, the BMS will only disconnect the cells if it has been overcharged. Max recommended charge voltage is around 14.6V. The absolute max cell voltage is ~4.2V or 16.8V for the pack. So BMS might cut out somewhere around there. A good battery charger would not exceed that voltage, or you can get specific lithium 12V chargers.Same for the motorcycles alternator, it should not exceed 15V unless something is wrong.
What topology is this PS AUDIO Powerpack UPS - Page 1
Forum section: electronics / general

author: CaptainBucko
author_rank: Regular Contributor
timestamp: July 19, 2024, 01:25:46 am
content: I picked up a PS Audio Power Pack 1500MkII from eWaste. It had dead SLA batteries (dated 2013) and a blown fuse. Replacing both of those and the unit appears to work as normal. From what I have read through google search, this is a decent UPS in terms of performance, and is true sine wave. I don't have a UPS for my lab, and this might be good for the sensitive test equipment.However, I don't understand the topology of this unit. I understand that true sine wave UPS generally rectify mains AC into high voltage DC and then digitally reconstruct the waveform back into AC. However, this unit has no large electrolytic high voltage capacitors or bridge rectifier justifying a 1500W rating. I cant find any schematic or service manual for this unit.The transformer shown in the photos is truly massive - there are four banks of four (16 in total) of IRF3205 MOSFETs. During normal mains AC operation, I can see 13v AC coming from the large winding that is connected to the FETs. The backup battery is 24v.I would appreciate any information on how the unit works as I am quite interested.EDIT & UPDATE : This is the topology.https://www.ti.com/lit/an/slaa602a/slaa602a.pdf
Pinout for Valence U1-12RJ RJ45 connector - Page 1
Forum section: electronics / general

author: R-1125F
author_rank: Regular Contributor
timestamp: August 13, 2024, 08:41:56 pm
content: I am looking for the pinout for Valence U1-12RJ battery with the RJ45 BMS connector. The pinout for the 5 pin connector is easy to find on the internet but that's not what my battery has. Anybody know the conections to the RJ45 version? I am hoping somebody knows before I have to remove the battery cover.
Where to source broken non chinese offgrid MPPT controllers and inverters?  - Page 1
Forum section: electronics / general

author: plopa
author_rank: Newbie
timestamp: July 15, 2024, 10:06:30 am
content: Hi all,i want to learn more about offgrid MPPT controllers and inverters and eventually want to be able to build my own designbased on existing proven and working designs from non chinese brands like for example:Victron, Studer, Midnite, Outback, SchneiderI found it very difficult to find broken units on ebay as they are probably often thrown away even when they where expensive to buy and the unit seem to fail more often like MPPT controllers.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: July 15, 2024, 12:35:48 pm
content: Maybe contact some local solar installers

author: Roehrenonkel
author_rank: Frequent Contributor
timestamp: July 15, 2024, 12:56:04 pm
content: Quote from: mikeselectricstuff on July 15, 2024, 12:35:48 pm...possibly with a crate of beer (or other local beverage), so they remember you. ;-))Good luck

author: f4eru
author_rank: Super Contributor
timestamp: July 15, 2024, 11:41:32 pm
content: You might get an "inverted survivorship" bias, i.e. analyzing only the models that like to failBut still a good idea.Please share the board photos

author: plopa
author_rank: Newbie
timestamp: July 17, 2024, 10:07:12 am
content: i already have learned a lot by following this tutorial:https://www.instructables.com/DIY-1kW-MPPT-Solar-Charge-Controller/i recommend anyone interrested in the topic to do the same.but i guess the commercial MPPT controllers have a lot more additional safety measures then this DIY MPPT and they still seem to fail quite often.from what do they fail? overvoltage? voltage spikes? just too small mosfets used at 100% which gets too hot?this things i want to research and avoid in my own design.

author: Psi
author_rank: Super Contributor
timestamp: July 17, 2024, 10:36:38 am
content: Quote from: plopa on July 17, 2024, 10:07:12 amInteresting,
What does this "K" mean in this ferrite bead datasheet?  - Page 1
Forum section: electronics / general

author: Jim from Chicago
author_rank: Regular Contributor
timestamp: July 16, 2024, 08:43:25 pm
content: What does this K mean? Kelvin?https://www.we-online.com/components/products/datasheet/742792012.pdf

author: selcuk
author_rank: Frequent Contributor
timestamp: July 16, 2024, 09:18:52 pm
content: Yes. Kelvin.Delta T means temperature difference. If you tolerate 20 degree temperature rise on this component, rated current is 3A. For 40 degree, it is 4A.

author: Jim from Chicago
author_rank: Regular Contributor
timestamp: July 16, 2024, 11:36:21 pm
content: Oh I get it now, thanks!
Temperature switch for fan - Page 1
Forum section: electronics / general

author: shridmaster
author_rank: Contributor
timestamp: July 16, 2024, 05:45:22 pm
content: I've never worked with mains AC so I wanted to get a sanity check here.I have a heat exchanger used to cool down an air compressor. This is switched on by a temperature switch, a TS2-010 from Dwyer. Attached are pictures of the wiring diagram, fan motor, and temperature switch datasheet.My thinking is that when the switch shuts off, the inductive load will cause an arc across the output and fry the contacts and create back emf into the grid. Am I way off? Is the drawing okay as is or do I need to add some sort of protection?Thanks in advance!

author: Poroit
author_rank: Frequent Contributor
timestamp: July 17, 2024, 08:45:41 am
content: If you have not worked with AC then I suggest you talk to an Electrician. Maybe a mate or friend of the family so you get a good rate.I think White is Neutral for Single Phase in the USA.You should be switching your Active wire.The Dywer TS2 relay contact is only rated for 5A Inductive and your motor plate says 5.2A so you will need an interposing relay or Solid State Relay that can handle the current.
NFET internal gate zeners? - Page 1
Forum section: electronics / general

author: Faringdon
author_rank: Super Contributor
timestamp: July 18, 2024, 06:02:16 am
content: Hi,The below STW40N65 FET shows back to back zeners in the gate source.Can these really be relied upon for VGS overvoltage protection?After all, it says abs max VGS is +/-25V, so these zeners must be rated above 25V?In which caase they cant be relied upon to keep Vgs below 25V?https://www.farnell.com/datasheets/2816088.pdf

author: Zero999
author_rank: Super Contributor
timestamp: July 18, 2024, 07:34:32 am
content: I would not rely on them. A device shouldn't be run at its absolute maximum ratings. Desin your circuit correctly, so the maximum gate-source voltage isn't exceeded.

author: Gyro
author_rank: Super Contributor
timestamp: July 18, 2024, 09:22:31 am
content: Can you see any electrical characteristics for the internal zeners in the datasheet? Zener voltage, current rating, slope resistance?No?Then you can't use them can you!How is it that you canstillbe asking questions like this?

author: Phil1977
author_rank: Frequent Contributor
timestamp: July 18, 2024, 09:49:05 am
content: These zeners are *only* for protecting the device from ESD at handling out of circuit.In circuit they should not be used.

author: Zero999
author_rank: Super Contributor
timestamp: July 18, 2024, 10:36:45 am
content: Quote from: Phil1977 on July 18, 2024, 09:49:05 amAnd even then, one should still follow the usual ESD handling precautions.
Electrical Installation - Page 1
Forum section: electronics / general

author: Lyaa
author_rank: Newbie
timestamp: July 04, 2024, 01:41:16 pm
content: Hello everyone,I hope this message finds you well. I am currently working on a project focused on the study and sizing of electrical installations as part of my engineering internship. I will be addressing the study of the lighting system in a part of the company, followed by the sizing of the electrical installation using Caneco BT software. This includes examining the power balance of electrical equipment. I am seeking theoretical sections that can help me better understand these aspects. If anyone has previous experience or has worked on a similar topic, I would greatly appreciate your insights and would welcome the opportunity to connect.Please feel free to reach out to me directly if you're open to discussing your experiences or sharing advices.

author: madires
author_rank: Super Contributor
timestamp: July 04, 2024, 02:18:08 pm
content: I'd recommend to learn about the local electric code (regulations about electrical installations), to check if there are any regulations about workplace lighting, and the lighting requirements for specific workplaces.

author: Lyaa
author_rank: Newbie
timestamp: July 04, 2024, 02:44:17 pm
content: Thank you for your response. I will definitely look into the local electrical code and the regulations regarding workplace lighting. I plan to use Dialux for my lighting study. Could you recommend any specific resources or manuals that might help me in this research?

author: madires
author_rank: Super Contributor
timestamp: July 04, 2024, 05:39:01 pm
content: Sorry, I don't know which regulations or standards are applied in your country.

author: jonpaul
author_rank: Super Contributor
timestamp: July 07, 2024, 05:06:10 am
content: Check existing standards for such installations closest to your country, eg IEC (EU) VDE/TUV (Germany) UL/ETL (USA)Expect to pay for the standards and reguations.Also see electrical and electricians forums.Mike Holt is an excellent forum in USA.https://forums.mikeholt.com/Bon ChanceJon
Voltage Follower Opamp Current Amplification/Inrush/Power Consumption - Page 1
Forum section: electronics / general

author: electrovanga
author_rank: Contributor
timestamp: June 18, 2024, 11:55:45 am
content: Hello,I got an idea that when I have a 6V, 1.5A(Max. Contionious) battery with an voltage follower opamp, I cantprovide more current and more outpu voltage with lower impedance in theory that I know. My question is do you think it is possible. I drive a dc brushed motor and i would like to compansate inrush current and the high voltage drop issue on the battery.I attach one example circuit. The question here is if i set the zener to 5.2V as referance voltage. How will the current supply amplified, battery will consume less current or the inrush current will be limited? I think I need a transistor to limit the inrush current.

author: mtwieg
author_rank: Frequent Contributor
timestamp: June 19, 2024, 01:55:18 pm
content: That circuit basically behaves as a linear regulator, reducing the 6V battery voltage to 5.2V. This will reduce inrush current, but not by much, and power efficiency will be bad.Normally one drives a brushed DC motor with high frequency PWM, which is very power efficient. By changing the PWM duty cycle you can soft-start the motor to reduce inrush.

author: electrovanga
author_rank: Contributor
timestamp: June 21, 2024, 11:50:48 am
content: My idea was after this circuit connect the half bridge to the output of opamp and apply PWM. I was imagining kind of double inrush current protection. Because, I can not really get what I want with soft start and PWM adjustment.

author: mtwieg
author_rank: Frequent Contributor
timestamp: June 21, 2024, 12:59:45 pm
content: Quote from: electrovanga on June 21, 2024, 11:50:48 amI don't think there's any protection this circuit provides that proper pwm control can't replicate (though the pwm control might be a bit complicated). Maybe you can describe the inrush issue in more detail? Does it happen when changing speed quickly, or when the load on the motor is increased suddenly? What is generating the PWM for the half bridge?

author: Circlotron
author_rank: Super Contributor
timestamp: July 04, 2024, 12:12:54 am
content: Maybe replace the zener diode with a capacitor that will charge up slowly, and by doing so will soft start the motor. And preferably put a diode across the resistor that feeds this capacitor to make the capacitor discharge when the power is removed.
How long can AVR Trim run safely on a UPS? - Page 1
Forum section: electronics / general

author: ParthuP
author_rank: Newbie
timestamp: July 21, 2024, 05:29:30 pm
content: The utility voltage in my country is 230-240V at nominal, but in my area it goes quite high (around 265V) at night in the colder months as not many people switch on their Aircon at that time.The PSU in my PC is rated for 100-240V input and it's said that +10% margin for input VAC is usually built in for most PSUs, meaning up to 264V.So I've set the high transfer point of my APC Smart-UPS SUA1500I-IND to kick in at 261 VAC.My utility voltage may remain at those elevated levels for several hours every night & into the early morning hours. So I'm wondering if AVR Trim being active for that long every day is going to result in any problem for the components of my UPS?If it helps, it's going to be pretty rare for the equipment connected to the UPS to be under any heavy load during those hours.
Inverter welder transformer insulation - safety - Page 1
Forum section: electronics / general

author: Circlotron
author_rank: Super Contributor
timestamp: July 03, 2024, 12:20:41 pm
content: Got myself a dirt cheap 120 amp inverter welder today. Ozito brand from Bunnings. AUD $104. Haven't used it yet. Opened it up of course to see what it's like inside. Interested in people's opinions on the insulation on the main transformer. Primary is whatever it is coated with and secondary is some kind of braided sleeving. Is this considered safe? I mean, it looks okay, but does it tick the boxes for something like this?

author: Phil1977
author_rank: Frequent Contributor
timestamp: July 03, 2024, 02:39:50 pm
content: It´d be interesting to see under the white fabric sleeving and to see the distances of traces on the PCB.If it needs to be safely galvanically isolated then such a fabric sleeving alone would not be sufficient. But I´m quite sure that there is additional insulation below the sleeving.On the other hand is the output of a welding transformer usually well connected to PE. So even if you have an insulation fault somewhere, the RCD or breaker trips, but -principally- you do not get shocked.The more dodgy parts in these super cheap hobby devices mostly are caps and filters and heatsinks. They probably are not designed for a very long operational life - but hopefully more than enough for occasional use.
LIR2032 button cells - Page 1
Forum section: electronics / general

author: Phil1977
author_rank: Frequent Contributor
timestamp: June 24, 2024, 09:13:43 am
content: Hi,maybe this kind of battery is to small for this forum, but anyhow: Has anyone experience with the rechargeable button cells?I ordered 10 and received 20. Now I´m tempted to use them everywhere where a CR2032 is needed.Their voltage is significantly higher than their CR2032 counterpart - they have 3,7V nominal 4,2Vmax compared to 3,2V nominal 3,6Vmax.Their short circuit current is also significant. If they cant in a narrow conductive holder metal can glow up and melt. Very impressive for such small cells!My question: Has anyone experiences to share? Can they be used e.g. in Apple Airtags? Are there any explosions to be reported? Has anyone experience with shelf-life and self-discharge?

author: tszaboo
author_rank: Super Contributor
timestamp: June 24, 2024, 09:23:05 am
content: I also ordered a few considering using it in consumer devices. But then the microcontroller is often times run from the CR2032 without anything in between. So I cannot judge if a device can use it without reverse engineering it. Disappointing.

author: bingo600
author_rank: Super Contributor
timestamp: June 25, 2024, 07:50:36 am
content: For CR2032 (3V) replacements, I bought some LIR2032 but didn't dare to use them in "electronics", too high voltage.Even the wife didn't like them in her "Tea lights", too bright she said.I have switched to ML2032.Think they're 60mAh, so still much lower than CR2032 .. But rechargeable ..Ie. Wifey has to switch batts' in Tea lights more often "But we're greener"

author: Psi
author_rank: Super Contributor
timestamp: June 25, 2024, 08:18:19 am
content: They are usually like 40mAh vs 220mAh for a normal CR2032.So you get rechargeablity and higher current but only 18% capacity.
problem with Sim6822m for BLDC  - Page 1
Forum section: electronics / general

author: benyamin.kh200
author_rank: Newbie
timestamp: June 19, 2024, 08:41:11 am
content: I am going to design a BLDC circuit i have prepared an IPM part number sim6822m my problem is here when IPM pinout connect to bldc motor the circuit does not turn on and no current flow and does not turn on IPM mosfet. it does not get hot and after cutting off the power supply the output of the IPM is 22 OHM with ground.why is this happening?my ipm has been damagedFile added below

author: mtwieg
author_rank: Frequent Contributor
timestamp: June 21, 2024, 01:14:35 pm
content: When bringing up a high power system like this it's a good idea to do testing in stages to reduce chance of damage (both to the hardware and yourself):1. Test just the board with the IPM and MCU (no motor connected). Just generate simple PWM waveforms from the MCU and verify that the IPM outputs are correct. Power the IPM output stage with a bench PSU set to low voltage and a low current limit (like 15V and 0.1A).2. Add your motor (or a smaller motor, if you have one) and test at the lowest possible speed and torque. Modify the controller to have a low current limit (by increasing your current sense resistor). Verify the IPM outputs still look clean, and that your feedback components are working properly.3. Gradually increase the operating power as you monitor its behavior.
Error amp output range of control for sync Bucks - Page 1
Forum section: electronics / general

author: Faringdon
author_rank: Super Contributor
timestamp: June 15, 2024, 10:20:37 pm
content: Hi,We wish to use either the LTC7803, or the LM25148 as a synch buck. But we need also to have an output current clamp, which can clamp the current by pulling down the comp pin..(eg an opamp error amp to pull down the COMP pin via a diode)....the thing is, to do this, you first need to know the COMP pin range of control voltages.....but neither datasheet says. Do you know these values?LM25148https://www.ti.com/lit/ds/symlink/lm25148.pdf?ts=1718487435081&ref_url=https%253A%252F%252Fwww.ti.com%252Fproduct%252FLM25148LTC7803https://www.analog.com/media/en/technical-documentation/data-sheets/ltc7803.pdf

author: jbb
author_rank: Super Contributor
timestamp: June 16, 2024, 07:44:52 am
content: For the LTC7803, I infer from the Functional Diagram that the ITH voltage range is: normally somewhere in the range of 0.65 - 2.7V (give or take slope compensation). I also see Sleep mode comparator at 0.425V

author: jbb
author_rank: Super Contributor
timestamp: June 16, 2024, 07:54:47 am
content: For LM25148, I infer:- current sense voltage (ISNS+ to VOUT) < 60mV to avoid overcurrent trip. This we could guesstimate… 50 mV nominal- current sense gain = 10. Thus we could say a range of about 0.5V- slope compensation present. This would increase the prospective voltage range a bit. Maybe 0.75V range? Total guess there…- but it’s not clear what DC offset is. It’s probably not zero- you could measure it on an evaluation board maybe? Or perhaps extract it from a SPICE model?

author: mtwieg
author_rank: Frequent Contributor
timestamp: June 16, 2024, 10:49:29 pm
content: Unfortunately most pwm controllers which handle slope compensation internally will not answer this.I've asked Linear Tech/ADI this same question about numerous parts in the past. They don't want customers to understand their current mode controllers in such detail, as it's proprietary IP to them. And their own LTspice models also often don't behave the same as real devices in this regard.Doesn't look like the LM25148 datasheet is any clearer about it.When I really need a PWM controller which is accurately modeled, I will use a simpler controller like the "unitrode" family of parts, i.e. UCxxxx or UCCxxxx). But then you will likely have to take care of slope compensation manually.

author: Faringdon
author_rank: Super Contributor
timestamp: June 17, 2024, 06:11:26 am
content: thanks, i suppose we will have to build a converter, and check the ITH voltage at no load...or light load....and progressively load it till it overloads, and see the range....then hope that all the other parts do the same thing. As you know, you need a diode in the pull down of the ITH pin...so if zero duty cycle correponds to around 1v or so then thats good..eg in ucc28c43 where the 2 internal diodes mean zero DC is around 1.4v.
MCP1630 with 0.33V current limit clamp? - Page 1
Forum section: electronics / general

author: Faringdon
author_rank: Super Contributor
timestamp: June 15, 2024, 08:51:42 pm
content: Hi,If i am using MCP1630 and want a 0.33V current limit (instead of the 0.9v), then may i just feed the COMP pin from the output of an opamp with 1V at non-inv and diode from COMP to opamp output, and negative feedback from COMP to opamp neg input? (as per attached)

author: georges80
author_rank: Frequent Contributor
timestamp: June 15, 2024, 09:32:54 pm
content: Yep, that will work great. Off you go and get that into production before China beats you to it.cheers.

author: Faringdon
author_rank: Super Contributor
timestamp: June 15, 2024, 10:10:22 pm
content: Thanks, the MCP1630 datasheet gives typ and min source currents from the EA output, but not max...so i was wondering from that point of view...i mean, technically, as you know, we shouldnt pull down an opamp output unless its deffo current limited, or, a transconductance error amp.MCP1630https://ww1.microchip.com/downloads/aemDocuments/documents/APID/ProductDocuments/DataSheets/MCP1630-V-Data-Sheet-DS20001896.pdf
Safe trickle/float voltage for li-ion or NiMH cells? - Page 1
Forum section: electronics / general

author: Freesurfer
author_rank: Regular Contributor
timestamp: June 09, 2024, 12:16:04 am
content: I know that the ideal way to charge a cell is with a charger that understands the difference charge phases and offers some kind of detection for when a battery is full.But sometimes you just need a quick hack that works for a hobbyist project..So I'm wondering if there is a battery chemistry or a safe float voltage that can be used to just make a very simple CC/CV charger made from a voltage regulator and current limiter of some sort. It does not need to charge the battery fully, nor operate the battery at its ideal maximum service life. It just needs to "work" and not catch fire..Can this be done with either li-ion or NiMH cells, with the voltage regulated to something below what would be considered the normal ending voltage?

author: Andreas
author_rank: Super Contributor
timestamp: June 09, 2024, 07:05:56 am
content: Hello,for my hobby projects I do the following for NiMH:1.45V / cell @ 20 deg CTemperature compensation -3 mV/cell above 30 deg CCheck that in charged state the charge current is well below C/50 .. C/100 (eventually reduce the float voltage)So a AA cell should stay below 30-50 mA at float voltageand a AAA cell well below 20 mA continously.But it is also essential to protect the cells from deep discharge.A charger for 12 AAA cells from USB can be found here:https://www.eevblog.com/forum/metrology/ad587lw-10v-precision-travel-standard/msg1449489/#msg1449489here the charging current is limited to 100 mA to stay below the 500mA of the USB port.In the project you also find a battery monitor to switch off in case of deep discharge.with best regardsAndreas
Decyphering an old fan motor - Page 1
Forum section: electronics / general

author: HannoB
author_rank: Contributor
timestamp: July 02, 2024, 06:37:19 pm
content: Hi guysSomeone gifted me an old fan motor. I want to turn it into a rudimentary drill bit sharpener. It is however giving me a difficult time in trying to figure out how to wire the thing. The nameplate is faded beyond readability.It has six wires, and came along with two capacitors, one 24uF and one 3uF (both rated 400V ac)I've attached the diagram of winding resistances I've measured.I'm assuming it is a PSC (Permanent Split Capacitor) type motor, common for fan motors.Questions:Which of the coils would be the start winding?Is there a right and wrong direction for the shaft to turn?Would excluding the 3uF cap cause any serious loss of efficiency?This is a bit of a tinkering around project. I find these PSC motors quite intriguing. Any assistance is much appreciated.

author: HannoB
author_rank: Contributor
timestamp: July 02, 2024, 06:52:20 pm
content: This is how I've currently wired it - supplied by a Variac with constant amp monitoring to ensure I don't burn any windings.It does rotate, however the moment I remove the capacitor from above circuit the rotor stops turning, which -according to my knowledge- should not happen as the "start winding" is only there to facilitate a slight phase angle difference to cause directional starting torque?Am I missing something?A good start would be to know if I'm even using the correct winding as the "Start winding"

author: Doctorandus_P
author_rank: Super Contributor
timestamp: July 03, 2024, 11:52:58 am
content: PSC = Permanent Split Capacitor, and this motor type is designed to be connected to a capacitor for it's whole life.