hybridfree/eevblog-posts huggingface dataset:
Semi-Flexible Solar Panel Advice - Page 1
Forum section: electronics / general

author: mscottydiy
author_rank: Newbie
timestamp: December 21, 2021, 12:54:06 pm
content: I've been looking into getting a new semi-flexible solar panel for my canal boat and I'm wondering if anyone has any experience with these?Are they practically any better than rigid ones?I'm wanting a semi-flexible panel so that it doesn't protrude too much. As far as I can tell, these things are pretty thin. Do I still need to leave a gap like you do with rigid ones?I've been looking into one by Renogy -https://uk.renogy.com/175-watt-12-volt-flexible-monocrystalline-solar-panel/As well as one by Sunpower -https://envirobuy.com/170w-sunpower-semi-flexible-solar-panels/The Renogy one is generally cheaper across the board although the Sunpower one is a better shape for my needs. Does anyone have experience with either?Cheers

author: Renate
author_rank: Super Contributor
timestamp: January 21, 2022, 07:08:27 pm
content: Me? I would NEVER buy anything that bends.They spot weld connections and with bending they fail.Renogy (who used to be HQST, except that they deny it) sold those.I threw away 3 100W panels.I now have 2 X 300W Canadian solar (solid) solar panels.The framework is mine.Edit: I remembered that about HQST

author: richard.cs
author_rank: Super Contributor
timestamp: January 21, 2022, 09:00:53 pm
content: I have a flexible panel I got off a friend because it flew off his van and hit the road as he was driving at 60 mph. It had 2 damaged cells, after shorting those it just worked with a slightly reduced output voltage indicating all remaining cells we OK, I was pretty impressed it survived that. The flexibility does seem to be fine, and bending once to match a curved boat roof is exactly what they're intended for. The one I have is 2-3 mm thick, aluminium backing, EVA front. I probably wouldn't bother with a gap, if you make it large enough for useful air circulation then you'll have lost all the advantage of a flexible panel. If mounting without a gap, then thermal contact between the aluminium back and the steel roof would be good as the board can then heatsink the panel a bit.

author: Renate
author_rank: Super Contributor
timestamp: January 21, 2022, 11:01:28 pm
content: Two damaged cells that you knew about.Who's to say that another connection didn't go flakey and that in the future it won't dump the entire solar panel power into a resistive connection?There have been melt-throughs. Google HQST.You might have a point with a metal roof but a wooden roof is a sub-optimal.

author: richard.cs
author_rank: Super Contributor
timestamp: January 21, 2022, 11:09:59 pm
content: Well yes, I certainly wouldn't recommend throwing them off the roof at speed, I was rather surprised it worked at all afterwards. It's been fine for years, but where it's installed a point dissipation won't cause a fire in any case.
TVS protection for hi side  IGBT  in SMPS? - Page 1
Forum section: electronics / general

author: Faringdon
author_rank: Super Contributor
timestamp: January 15, 2022, 10:43:33 pm
content: Hi,If you have a 3.6kW Half Bridge SMPS, using IXER35N120 IGBTs (fsw = 20kHz) .......then is the P6KE18CA TVS going to be good enough to protect the IGBT Gates from transient overvoltages?The Abs Max of the gate voltage is 20V.IXER35N120 IGBThttps://www.mouser.es/datasheet/2/240/l518-1548005.pdfP6KE18CA TVShttps://www.littelfuse.com/media?resourcetype=datasheets&itemid=3ba2705e-3e6f-49cc-b247-92bd0aed9fd5&filename=littelfuse-tvs-diode-p6ke-datasheetIs it right that we are to consider that P6KE18CA's TVS current goes linearly from 1mA at 18.9V to 24.2A at 25.2V?If this was the case, then at 20V, the P6KE18CA TVS would conduct up to 4.2A

author: T3sl4co1l
author_rank: Super Contributor
timestamp: January 15, 2022, 11:58:22 pm
content: What transient voltages?Tim

author: David Hess
author_rank: Super Contributor
timestamp: January 16, 2022, 12:56:05 am
content: Quote from: Faringdon on January 15, 2022, 10:43:33 pmAssuming that you are driving the gate to full saturation with 15 volts, sure, the P6KE18CA will work fine.

author: Faringdon
author_rank: Super Contributor
timestamp: January 16, 2022, 11:41:37 am
content: QuoteThanks, its just the general "malaise" thats going to find its way through the IGBT stray junction capacitances and potentially blow up the gate.QuoteThanks, it seems amazing that this P6KE18CA can only draw 1mA with 18.9V across it, then with 20V across it it can draw 4.2A.I wonder how a zener in the same package would perform?

author: David Hess
author_rank: Super Contributor
timestamp: January 16, 2022, 02:31:20 pm
content: Quote from: Faringdon on January 16, 2022, 11:41:37 amA zener would work the same since they are essentially the same thing.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: January 16, 2022, 06:05:27 pm
content: Quote from: Faringdon on January 16, 2022, 11:41:37 amThat's why you don't take inverter designs from Jimmy Carter. Mine simply don't do that...Such an element might be gainfully employed to protect the gate driver, such as in a modular system where the drivers are relatively expensive, and IGBT destruction can't be avoided through other means (or multiple layers of protection are desired).Tim

author: jonpaul
author_rank: Super Contributor
timestamp: January 16, 2022, 08:09:52 pm
content: Bonjour David: A TAZ is a large area Zener specifically rated and tested on standard pulses with defined wave shape, current etc.TAZ have specified clamp V and certain currents, but cannot dissipate long-term. The large die in a small package was developed at General Semi decades ago. Yes they are Zeners but not interchangeable!In the case of gate protection, a TAZ is not usually needed and a Zener can serve as the current is limited by the driver.Beware of the Zener shunt capacitance on the driver performance.Bon chanceJon
LTC3780 step up down board schematic  - Page 1
Forum section: electronics / general

author: 1.6e-19
author_rank: Newbie
timestamp: January 11, 2022, 04:34:06 pm
content: Hi guys,this widely available LTC3780 board (hope photo appears somewhere below) is quite nice for all kinds of voltage and current sources.Being an step up/down it provides CV and CC from almost any input voltage.Alas, as often with these cheap chinese boards, it has at least one flaw: the input undervoltage protection has no hysteresis and apparently no lowpass. Making it overly sensitive - when you want to use that feature.I fiddled in some positive feedback to the comparator, so it gets a hysteresis, what works quite well.But still the thing is too sensitive and tends to get unstable.HAS ANYONE SEEN A CIRCUIT DIAGRAM of this board? Would help a lot debugging. Maybe some components are wrong, would not be first time on such boards.

author: Faringdon
author_rank: Super Contributor
timestamp: January 16, 2022, 11:55:25 am
content: https://www.analog.com/media/en/technical-documentation/data-sheets/LTC3780.pdfHave you tried come capacitance on the RUN pin?Otherwise, you could just make an inline module for it, which does UVLO with required hysteresis...then connect the LTC3780 to that...You would then disable the one on the LTC3780 board......change the resistor to RUN pin or whatever.
comparing calculation for AMOLED and LCD used in bright  - Page 1
Forum section: electronics / general

author: abdulbadii
author_rank: Frequent Contributor
timestamp: January 14, 2022, 01:23:28 am
content: So how is the comparing calculation for AMOLED and backlit LCD used in bright day (so few black/dark display performed),is AMOLED still more efficient and less power consuming than Lcd on such condition?Question was following the concluding answers on Quora that Amoled is clearly more efficient if black parts are displayed more (often)
What is max voltage allowed on TRM pin of power module? (TUNS500F) - Page 1
Forum section: electronics / general

author: Faringdon
author_rank: Super Contributor
timestamp: January 10, 2022, 07:39:11 am
content: Hi,(Sorry to ask again about this power module, but i thought info could be useful to others too)We want to use the TUNS500F ACDC power module for 48V, 7A5 PSU.Does anyone know the absolute maximum voltage that can be applied to the "TRM" pin?The Applications manual, on page "TUNS-26" talks about it, but doesnt give the value.There's a family of modules, and the literature is a little unclear as to what page applies to which particular module.datasheethttps://en.cosel.co.jp/tool/tag/pdf/SFE_TU.pdfInstruction manualhttps://en.cosel.co.jp/tool/tag/pdf/CME_TU.pdfApplications manualhttps://en.cosel.co.jp/tool/tag/pdf/TU300_500_700_manual.pdf
Lenze EVF9327-EV frequency inverter - Page 1
Forum section: electronics / general

author: gaminn
author_rank: Frequent Contributor
timestamp: January 12, 2022, 01:36:20 pm
content: Hi,I got EVF9327-EV and I would like to check if it is operational. I have a control display connected to it. The problem is it always shows IMP status on the display even though I connected HI to X5/28 pin to enable controller. There is GND of external 24V power supply connected to PE and X5/39 and +24V connected to X5/28. The only thing that happens when there is rising edge on X5/28 is "CIHN int 1" text on the display.I also did factory reset of the controller by setting CODE 0002 to 0.Can you please help me with enabling the controller? Or is it faulty? Because I tried this procedure also with e.g. EVS9323-EK and it enabled it.

author: HighVoltage
author_rank: Super Contributor
timestamp: January 12, 2022, 01:40:24 pm
content: I am not familiar with this Lenze model but the Lenze manuals are usually very good in setting up the inverter.Also, depending on your country, Lenze has a very good customer service and they walk you through the setup.

author: gaminn
author_rank: Frequent Contributor
timestamp: January 12, 2022, 07:41:51 pm
content: https://inverterdrive.com/file/Lenze-9300-Vector-Manual-0-37-90kW-v3section 6.3 has nice description what to do. I was able to run my motor, but still has problem with speed setting - potentiometer connected to X6 doesn't set the speed.

author: HighVoltage
author_rank: Super Contributor
timestamp: January 12, 2022, 09:10:07 pm
content: If the motor runs, you need to set it to local controlYou also need to set all motor parametersThere is also some bridge you need to apply to some contacts, if I remember correctlyYou also need to set min and max frequencies for the motor controlOnly if you have set all parameters correctly, will the potentiometer work,
Nailable Solar Shingles - Page 1
Forum section: electronics / general

author: graybeard
author_rank: Frequent Contributor
timestamp: January 05, 2022, 08:01:28 pm
content: I just read avery interesting article about Solar Shingles that can be nailed into place. Seem like an interesting idea.

author: richard.cs
author_rank: Super Contributor
timestamp: January 06, 2022, 10:56:57 am
content: It's a nice idea, I worry about the reliability of so many electrical connections to individual shingles.I am not entirely sure I see the advantage of them being the size of a normal roof shingle rather than say double width and height which would still allow them to be intermixed with normal shingles but have 1/4 as many connections.Edit: I see they are actually much wider.That said I am unfamiliar with shingle roofs, they are very rare here.
$200 WaterLily Turbine Generator - Page 1
Forum section: electronics / general

author: NurseBob
author_rank: Newbie
timestamp: November 19, 2021, 09:48:51 pm
content: Interesting if it works. But too pricey for and way too heavy for a backpacker. If I'm off-road in my FJ, no need for the device. They also offer a wind-powered generator.https://shop.waterlilyturbine.com/?utm_source=FB-AD&utm_medium=BF-INTEREST-SOLAR-POWER-VIDEO&fbclid=IwAR21fXvwTIwz94Mx06tHg8mLD5Rili7mrRG7Qb6mCJUh9u1H9HKUlp5keuc

author: BatGroupCraft
author_rank: Contributor
timestamp: January 06, 2022, 08:11:56 am
content: So it's a hand-sized river turbine that generates up to 15W of power. I'd look at YT videos of people that want to rate them.https://www.youtube.com/results?search_query=WaterLily+Turbine+

author: wraper
author_rank: Unknown
timestamp: January 06, 2022, 08:24:52 am
content: You'd be better off with solar power bank frankly. When you are somewhere near Earth poles during polar night, of course that will not work. However rivers most likely will be frozen too.
Battery internal resistance. Its truthful science knowledge  - Page 1
Forum section: electronics / general

author: abdulbadii
author_rank: Frequent Contributor
timestamp: November 30, 2021, 11:29:59 pm
content: What is it all about on NiCd recharge battery internal resistance (BIR), as its knowledge onhttps://www.quora.com/How-do-you-test-AAA-batteries-with-a-multimeter/answer/Almaghfuur-Lahuroughly tell this mind-confusing one which has at least 7.7 ohm BIR due to MM tested it 1.53 V 0.17 Ahow to reduce or "dissolve" this BIR

author: Siwastaja
author_rank: Super Contributor
timestamp: December 01, 2021, 08:19:16 am
content: I can't understand the Quora post.For equivalent DC resistance, "dynamic resistance" is easiest to measure, and offers useful real-life number which you can then use to estimate voltage drop with given current, and heat dissipation in the cell.Use two dummy loads of different resistances, which are significantly different. For example, if you have a cell with maximum rated discharge current of, say, 1A, you could use dummy loads of around 0.1A and 0.5A.Connecting the first dummy load, keep it connected for at least 10-20 seconds, then read test current I1 and cell voltage V1.Repeat for another test load.Then,Rdc = dV / dI = (V2 - V1) / (I2 - I1)If the loads are connected for too long, the cell discharges during test, causing an error. You can significantly reduce this error by measuring the first dummy loadagain(i.e.: sequence of loads: 1 - 2 - 1), and use the averages of the two measurements for V1, I1.

author: mag_therm
author_rank: Frequent Contributor
timestamp: December 02, 2021, 02:00:51 am
content: NiCd..Here is a good report of hands on impedance test back in their day.https://apps.dtic.mil/sti/pdfs/ADA111687.pdfI recall that one reservation about the new NiCd and also the merging Lead Acid variants at the time, was that UPS would"lay down" in voltage during a sudden utility trip. But I don't know if that was true.I expect the subject of battery impedance will be topical as transient storage becomes more common.

author: BatGroupCraft
author_rank: Contributor
timestamp: January 05, 2022, 08:20:15 pm
content: was studying these graphs of 18650 DCIR vs number of cycles and apparently LG last a lot longer despite having higher DCIR.https://endless-sphere.com/forums/viewtopic.php?f=14&t=114473&p=1694384#p1694384
Li-ion cell 18650 damage and future durability - Page 1
Forum section: electronics / general

author: Texx
author_rank: Newbie
timestamp: January 04, 2022, 12:14:27 pm
content: I was soldering cooper bar to 18650 chemistry (LiO2 (H-NMC) / Graphite + SiO). Got a while dreaming about somethingand kept soldering iron probably too long to positive pole of cell. It throw a small flame out probably through safety vent. I guess it was hydrogen gas? Got scared me good but I instinctively blown it off like a candle. Than it quickly stopped.What are future durability of affected cell? Is it smaller capacity now? Could it catch fire more easily on next thermal shock? Battery pack shows normal voltage, have not yet started to charge it or heavy discharge yet. Should I throw it out (mean cell) as battery pack is too expensive. Or vent did its job, and cell can still be used? Any real life comments?THX

author: Siwastaja
author_rank: Super Contributor
timestamp: January 04, 2022, 12:16:53 pm
content: It's not hydrogen. Possibly the flammable electrolyte itself leaked through the pressure vent. Or maybe just some material outside of the container itself burned, for example the seal material.Pretty obviously, don't use it, get a new cell.External heat damage is worst kind of abuse to these cells.Disposing unsafe li-ion cells is always problematic. I would just fully discharge it inside a safe metal container and then forget about it.

author: BatGroupCraft
author_rank: Contributor
timestamp: January 05, 2022, 08:14:17 pm
content: Yes the electrolyte is like a plastic or an oil. I have spot welded 100ds of 18650's and one day i short circuited some copper for enough time so that the negative steel side was pierced, and a little bubbling flame of melting liquid that looked like wax was visible there, the electrolyte can bubble. To the recycle facility.
Has anyone heard of Powerfoyle? - Page 1
Forum section: electronics / general

author: Ranayna
author_rank: Super Contributor
timestamp: November 29, 2021, 02:18:50 pm
content: Has anyone here heard about Powerfoyle?There are now headphones available that charge with a "Powerfoyle" solar panel in the headband. Somewhat surprisingly, that apparently even works decently, i just read a test that even cloudy German autumn sun is sufficient to charge the headphones, with an app screenshot showing around 13 mA current coming from the panel, with the headphones using a bit more than 3 mA.I was not able to find much details about this "Powerfoyle". All websites are either pretty marketing pages or other sites testing the headphones.Supposedly, Powerfoyle uses the principle of photosynthesis. For me that sounds like pure marketing hogwash.

author: ejeffrey
author_rank: Super Contributor
timestamp: November 29, 2021, 04:24:57 pm
content: I'm guessing they are using organic photovoltaics. That is a screen printable thin film process. It's been the next big thing in PV for a few decades now but resisted commercial applications. Originally the promise was PV as cheap as paint to replace silicon panels for building / fixed installations but the enormous drop in price if silicon makes that pretty hard to compete with. A pivot to consumer electronics makes sense since you can sell that with marketing and side features a lot easier than for a fixed installation where TCO is about the only factor.

author: rpiloverbd
author_rank: Regular Contributor
timestamp: December 26, 2021, 08:18:37 am
content: Yeah. Not that much content is available yet. Would really like to see some honest reviews.

author: Munyua44
author_rank: Contributor
timestamp: January 13, 2022, 09:05:31 am
content: I do agree with you it is being inspired by the process of photosynthesis. for a bit of more information you can go through it herehttps://www.powerfoyle.com/
Looking for a Lithium charger Module/Pcb with a booster output... (SOLVED) - Page 1
Forum section: electronics / general

author: EvilSOB
author_rank: Newbie
timestamp: December 28, 2021, 01:16:01 pm
content: Hi yall.Im looking for a small module/pcb to charge an unprotected lithium cell,and give me a 9v 250-500ma output, but Im having trouble searching,Im just getting too many useless results.So can you guys please supply me with some links to existing or expiredadverts / specs / ebays / etc, so I can find some, and improve my searching skills.Requirements:5v Usb input charge socket9v 20- 500ma max output pins/padsLithium cell over-charge and over-current protectionSmall footprint as possible.Australian supplier.retailer preferred, ebay OKLess than 10 units required so not bulk supplier.Li-Ion / LiPo ?? Whatever an 18650 is... both would be nice, either will do.Thanks guys.Al

author: Faringdon
author_rank: Super Contributor
timestamp: December 28, 2021, 04:01:49 pm
content: What is an 18650 battery? The 18650 battery is a lithium-ion cell classified by its 18mm x 65mm size, which is slightly larger than a AA batteryhttps://www.batterypowertips.com/difference-between-lithium-ion-lithium-polymer-batteries-faq/...Some Lithiums have lower voltage...eg LiFe-Po4 is about 3.2V, whereas li ion and LiPo are 3.7V nominal....but you can charge Li ion and LiPo up to 4.2V/cell.Beware because LiFePo4 also comes in 18650 size.Try Recom, Meanwell and Mornsun....they do current regulators.I presume you dont want to make your own?...in truth, a boost converter wouldnt be used, as it doesnt have good output short circuit protection.....unless you add in an extra fet and overcurrent shutdown.I'd do it as a buckboost converter, or sepic.

author: Peabody
author_rank: Super Contributor
timestamp: December 28, 2021, 05:08:12 pm
content: I think you will have trouble finding such a module. There is something called "18650 shield V3" which is a charger, with protection, for a single unprotected 18650 cell, with a 5V boost regulator. It might be possible to change the feedback resistors to get 9V output, but I don't know if the booster chip, inductor and diodes will handle that well. Mine uses the FP6298 chip, and its data sheet claims it can output up to 9V.An alternative would be to use a TP4056 charger module with protection, and a separate adjustable MT3608 boost regulator module. Those might be easier to find.But that leaves the question of whether you need to have a load sharing (aka power path) circuit, which would involve adding a mosfet, Schottky diode and resistor. Charging modules do not typically have that feature.http://ww1.microchip.com/downloads/en/AppNotes/01149c.pdf

author: tunk
author_rank: Super Contributor
timestamp: December 28, 2021, 05:24:19 pm
content: Something like this?https://www.ebay.com/itm/192481862428?hash=item2cd0d0231c:g:0D8AAOSwjL5ZEo90Found by searching for this: 18650 boost charge

author: EvilSOB
author_rank: Newbie
timestamp: January 04, 2022, 07:45:46 am
content: Thanks for the replies guys, but Tunk wins the day.He gave me exactly what I was looking for.Tanks Tunk!
Tesla manufacturing record in 2021 - Page 1
Forum section: electronics / general

author: Picuino
author_rank: Super Contributor
timestamp: January 03, 2022, 07:31:12 pm
content: Tesla delivers a record 936,172 electric cars in 2021https://www.dailymail.co.uk/news/article-10363361/Tesla-says-delivered-record-936K-vehicles-2021-87.html2021 production:https://ir.tesla.com/press-release/tesla-q4-2021-vehicle-production-deliveriesAlmost doubles 2020 production:https://ir.tesla.com/press-release/tesla-q4-2020-vehicle-production-deliveries

author: f4eru
author_rank: Super Contributor
timestamp: January 04, 2022, 09:20:29 am
content: Cool.The nice thing is that it will probably almost double again in 2022.Now that is a growth rate.https://www.statista.com/statistics/502208/tesla-quarterly-vehicle-deliveries/

author: aheid
author_rank: Regular Contributor
timestamp: January 04, 2022, 03:59:55 pm
content: Here in Norway 80% of new cars sold in 2021 were electric, though this includes hybrids. Tesla Model 3 was the most sold model, and at least seven of the top 10 models are pure BEVs.It's not long ago Norway sold half the number of Teslas made, now we're a small fraction.https://e24.no/det-groenne-skiftet/i/34X0Wv/ny-elbil-rekord-over-110000-biler-solgt-i-2021Notably the sale of EVs is starting to take off in the rural areas.
Old Fashioned Half Bridge converter - Page 1
Forum section: electronics / general

author: Faringdon
author_rank: Super Contributor
timestamp: December 31, 2021, 02:43:01 am
content: Hi,The attached is a well known, old fashioned open loop Half Bridge SMPS of 833W output power. (PDF schem and LTspice attached)It relies on transformer leakage inductance instead of an output inductor. At 107us, there is an enormous shoot-through event due to the top FET turning ON, just after the diode of the bottom FET had been conducting. (This is during the startup event, but could also happen in load transients).Would you agree that this SMPS really needs SiC type FETs? Eg as follows…https://fscdn.rohm.com/en/products/databook/datasheet/discrete/sic/mosfet/sct3060al-e.pdfWould you agree that the following non SiC FET is unsuitable here? (STW20NB50)…..https://www.mouser.co.uk/datasheet/2/389/stmicroelectronics_cd00001063-1204680.pdf
L5991 Controller can do 100% Duty cycle? - Page 1
Forum section: electronics / general

author: Faringdon
author_rank: Super Contributor
timestamp: December 29, 2021, 07:29:47 pm
content: Hi,Page 1 of the L5991 controller datasheet says it can do 100% duty cycle.However, elsewhere in the datasheet, there is no instruction on how to allow it to do 100% duty cycle.Can L5991 do 100% duty cycle?L5991 controller datasheethttps://www.st.com/resource/en/datasheet/l5991.pdf
Buck converter gate drive is unsuitable? - Page 1
Forum section: electronics / general

author: Faringdon
author_rank: Super Contributor
timestamp: December 27, 2021, 10:12:41 am
content: We have a 750W Buck sent in by a customer. They want the same , but cheaper. (42vin, 24vout)We think its gate drive is dodgy (schem 1)We think schem 2 improves it.Do you agree?(LTspice and PDF schems attached.

author: f4eru
author_rank: Super Contributor
timestamp: December 27, 2021, 11:14:07 am
content: why not use a proper gate drive IC, with an UVLO ?

author: Faringdon
author_rank: Super Contributor
timestamp: December 27, 2021, 05:48:16 pm
content: Maybe liek in the attached yes, ie, using a very common gate driver, but otherwise, we cant , because of future supply issues.(LTspice and pdf schem attached)

author: T3sl4co1l
author_rank: Super Contributor
timestamp: December 27, 2021, 07:05:40 pm
content: The transformer is better I suppose because it provides some supply to the bootstrap supply, whereas a pure (nonmagnetic) bootstrap driver won't start up, or not reliably anyway.Solution of course is to use a charge pump type like HIP4080.Tim

author: Faringdon
author_rank: Super Contributor
timestamp: December 27, 2021, 11:35:53 pm
content: QuoteThanks, yes, the controller needs to wait for the bootstrap cap to get fully charged via the output divider before starting up.....but after that its ok though.Thanks for the HIP4080 , it looks great, ...as you know, there is significant fear at the moment that these kind of chips may become difficult to source.
IEC 60320 C13/14 contacts? - Page 1
Forum section: electronics / general

author: Marsupilami
author_rank: Frequent Contributor
timestamp: January 07, 2022, 02:06:19 am
content: Hi Folks!I'm not sure if this is the best category but I couldn't find where to ask.I need a very (very) low profile C13 right angle plug. I thought I'd machine the housing from appropriate grade ABS or so (still needs research) and I'll just buy the contacts but to my surprise I can't find any.I was imagining something like this:But either they're not available for the general public or I just don't know how to search for them.Any tips?Thanks!

author: f4eru
author_rank: Super Contributor
timestamp: January 07, 2022, 08:38:44 am
content: Search for "C13 plug insert"https://www.alibaba.com/trade/search?fsb=y&IndexArea=product_en&CatId=&SearchText=C13+plug+insert&viewtype=&tab=

author: Marsupilami
author_rank: Frequent Contributor
timestamp: January 07, 2022, 12:44:23 pm
content: That's great, thank you!Now I only have to find someone selling less then 1000.

author: electr_peter
author_rank: Unknown
timestamp: January 07, 2022, 03:46:14 pm
content: Another suggestion (considering poster wants low quantities) - buy only IEC connector without cable and extract pins. Or modify plug to fit required dimensions mechanically, then fill voids with epoxy/glue for wire retention. Example on AliExpressIEC Straight Cable Plug Connector C13 C14

author: Marsupilami
author_rank: Frequent Contributor
timestamp: January 07, 2022, 05:44:46 pm
content: Yeah, I was thinking about this, but it's a hit or miss whether the stuff is actually salvageable.This is the best I could find so far:https://www.newark.com/schurter/4787-2000/connector-power-entry-15a-250v/dp/67C2554?CMP=e-email-sys-orderack-GLBI ordered a couple. It's still longer then I would like it but maybe I can bend the solder tabs and bring the whole thing in under 30mm.
Zenor Minimum current - Page 1
Forum section: electronics / general

author: agganitk
author_rank: Newbie
timestamp: December 26, 2021, 09:07:29 am
content: HelloI need to calculate minimum current required for zenor to work. please suggest. I am looking at data sheet of ONSEMI MM3ZxxxST1G Series series.Please also suggest highlighted terms. Not clear to me.

author: f4eru
author_rank: Super Contributor
timestamp: December 26, 2021, 11:01:10 am
content: Look at "Figure 4. Typical Leakage Current"you can determine there the leakage current for your Vz and your max temperature (including self heating)Then see to always be at least 2-4x over this leakage current.

author: SeanB
author_rank: Super Contributor
timestamp: December 26, 2021, 04:16:45 pm
content: Also remember that the zener voltage is only going to be correct at the test current, 5mA here, and at lower current the voltage will be less, at worst case, at 1V it will be some specified current. Zener diodes at low voltage you have to run them at the specified current if you hope to be close to the marked voltage, they are very poor if you move out of this small range of currents.In the datasheet snippet you use, your zener diodes are going to be only the rated voltage at 5mA, while in reality they are all from the same wafer, sorted at 5mA into bins, as the actual voltage is very variable across the wafer, only being determined on test as to the bin they go in, if they are not too leaky. Tested and the bad ones marked out, then sliced, the bad areas removed, and then packaged, and tested again to see which marking and bin they are going to get. You can get from T2 to T7 on the same wafer, with the next one being say T4 to TC.
Help me identify the chip on this cheap-ass mppt - Page 1
Forum section: electronics / general

author: Octetz
author_rank: Newbie
timestamp: November 02, 2021, 08:13:04 am
content: Hi!I ha

author: rpiloverbd
author_rank: Regular Contributor
timestamp: December 08, 2021, 10:15:59 am
content: Hello,The question is incomplete. Please edit the question. Also attach a close picture of the chip that you want to identify.
Question storage battery - Page 1
Forum section: electronics / general

author: tiago1986
author_rank: Regular Contributor
timestamp: November 25, 2021, 11:17:50 am
content: I was recommended to store Li-Po or Li-ion smartphone batteries for the long term with a charge between 3.75v and 3.80v, today I measured the voltage of the BM20 and BP-5L batteries and they are with 3.74v at this voltage. do I need to recharge again to 3.80v?

author: tunk
author_rank: Super Contributor
timestamp: November 25, 2021, 01:50:04 pm
content: No. Monitor them regularly and if they drop below e.g. 3.5V, charge them to e.g. 3.8V.

author: tiago1986
author_rank: Regular Contributor
timestamp: November 25, 2021, 02:09:27 pm
content: i charged to 3.8v and stored these two batteries for 2 or 3 months and now they are at 3.74v and i thought it was to recharge

author: Faringdon
author_rank: Super Contributor
timestamp: November 25, 2021, 05:31:39 pm
content: LiPo Cell Voltage:The usable voltage range for a standard lipo battery cell is 3.2v to 4.2v. Any lower than 3.2v and the battery may be permanently damaged. Any higher than 4.2v and you significantly increase the risk of a battery bursting into flames.So keep it above 3.4V and you should be ok.LiFePo4 Is a bit lower voltage than Li-po, but you are not using that?

author: tiago1986
author_rank: Regular Contributor
timestamp: November 25, 2021, 05:59:27 pm
content: my batteries are xiaomi BM20 and Nokia BP-5Lcurrently their charge is at 3.74v do you recommend me to charge to 3.8v or not?

author: Gyro
author_rank: Super Contributor
timestamp: November 25, 2021, 08:21:58 pm
content: It seems to me that you have covered this ground before - maybe 6 times!https://www.eevblog.com/forum/renewable-energy/temperature-and-voltage-keep-battery-lipo/Go and re-visit your previous threads!

author: Siwastaja
author_rank: Super Contributor
timestamp: November 28, 2021, 10:11:10 am
content: If you measured voltage just after charging, that is not a reliable indication.Now, after 2-3 months they definitely show the true open-circuit voltage.Now, lookagainafter next 2-3 months. If the voltage still continues dropping, then that's an indication of relatively high self-discharge cells, indicating poor cell quality. But don't make this conclusion yet.

author: tiago1986
author_rank: Regular Contributor
timestamp: November 28, 2021, 11:51:55 am
content: I charged it to 3.8v, checked the voltage with a multimeter and kept the batteries for 2 or 3 or 4 months I don't remember after that period I tested it again with the multimeter and the voltage is at 3.74v. Will I need to recharge today to 3.8v?

author: Psi
author_rank: Super Contributor
timestamp: November 28, 2021, 12:13:22 pm
content: Your question has been answered at least 3 times.

author: Siwastaja
author_rank: Super Contributor
timestamp: November 30, 2021, 12:04:15 pm
content: Just record the current date and current voltage on a piece of paper. Don't do anything else. Measure again after a few months, if still interested.
Flash memory NOR chip retention data - Page 1
Forum section: electronics / general

author: tiago1986
author_rank: Regular Contributor
timestamp: November 28, 2021, 11:22:09 am
content: in the datasheet of my flash memory NOR ST M29W640FT 70N6 H has a data retention of 20 years, is it possible to increase this retention time to unlimited? the chip is installed in a snes cartridge

author: Jeroen3
author_rank: Super Contributor
timestamp: November 28, 2021, 12:45:11 pm
content: Didn't you already get your answers here?https://www.eevblog.com/forum/microcontrollers/questions-nor-flash-memory/

author: ataradov
author_rank: Super Contributor
timestamp: November 28, 2021, 05:55:36 pm
content: Here we go again. No, physical things degrade with time. It is impossible to make things last forever. Literally nothing in the Universe lasts forever.20 years is just an industry standard "forever, but don't sue us if something fails". In reality under room temperature conditions it will last as long as your physical package lasts. No manufacturer would want to investigate failures on a 20 year old device.Also, if you are worried about the contents, just refresh it every 10 years. 20 years retention is from the last erase and write time.Also, PCBs themselves degrade with time and also have limited time.But we have already discussed that.
Dual power supply card, but I want to power one IC only on one source - Page 1
Forum section: electronics / general

author: Snoov
author_rank: Newbie
timestamp: December 27, 2021, 03:54:55 pm
content: Hi there,It's difficult to make a title explaining what I want, but thanks for your clickI am designing a device with can be powered by:4 AA batteries (up to 6.6V when having new batteries)OR USB 5VThe power source is exclusive (the USB port is mechanically mounted behind the batteries, so I can ensure that both power sources are not running at the same time).I want to add an FTDI-like chip, that I need to work only when USB cable is plugged. This chip input voltage is 5.5V max.So I can not link USB voltage directly with battery voltages, otherwise the FTDI will fry when the system is powered with batteries.What can I do to solve my problem?I though about a power MUX like this one:https://www.ti.com/lit/ds/symlink/tps22933.pdfBut I don't know if it is a good solution, or if there is another simplier way to do this.Also note that the "System" is a "low-power" device designed to run about 24 hours with 4 AA batteries. So I can not add a 5V regulator between battery supply and 3V3 and 13.6V regulators, or I will loose efficency.Thanks!

author: f4eru
author_rank: Super Contributor
timestamp: December 27, 2021, 11:38:19 pm
content: simplest way is two schottky diodes.a single P-mosfet to reduce battery losses on the battery path is good addition for optimal battery usage...suggesting a simple control for it like a voltage comparator to make the mos + comparator an equivalent perfect diode

author: Snoov
author_rank: Newbie
timestamp: December 28, 2021, 08:01:26 am
content: Hi f4eruThanks I will look into that.I also need to work on polarity inversion of the batterie, so it will also solve this.

author: sleemanj
author_rank: Super Contributor
timestamp: December 28, 2021, 08:31:30 am
content: Run your FTDI at 3.3v

author: Snoov
author_rank: Newbie
timestamp: December 28, 2021, 09:01:09 am
content: Ow this is clever, didn't though about that.Thanks!

author: NiHaoMike
author_rank: Super Contributor
timestamp: December 28, 2021, 02:16:09 pm
content: How about use a USB-C socket and connect the system power to one side and the FTDI to the other? They'll only be joined when a cable is plugged in.
Identifying a connector used in APC BackUPS device - Page 1
Forum section: electronics / general

author: optoisolated
author_rank: Unknown
timestamp: November 19, 2021, 06:59:30 am
content: Hi,I am trying to get new batteries for an APC BackUPS RS 800 but i dont have the original wiring harness for the battery. Connecting the batteries is trivial, but it uses some sort of connector that I've not seen before. Anyone able to identify it?

author: f4eru
author_rank: Super Contributor
timestamp: November 19, 2021, 02:17:26 pm
content: any marking molded in the plastic plug, or in the receptacle of the UPS ?What is the exact pitch and width of the pins ?
Exercise bike generator - Page 1
Forum section: electronics / general

author: Faringdon
author_rank: Super Contributor
timestamp: November 16, 2021, 11:42:35 pm
content: Hi,For exercise bike, do you know the cheapest way to get it done?Say a BLDC...and connect pedal shaft to rotor.....then make stator field lead rotor field...ie, make the user pedal the south pole to the south pole, so they feel the repulsion force as they go round....more current...more force (more uphill?)Or is it cheaper to just pedal into battery (with BLDC in regen) and have inverter from battery regen'ing back into mains. kind of green anergy aswell?

author: NiHaoMike
author_rank: Super Contributor
timestamp: November 16, 2021, 11:58:01 pm
content: Cheapest is a MPPT controller direct to portable electronics, nowadays that would be using USB-C. Unlike a grid tie inverter, it will work without the grid which would be a great selling point - doubles as a backup power source!For my senior design project, I built an exercise bicycle with a grid tie inverter, but the grid tie inverter is really mostly to add something that's not trivial to implement.

author: fourtytwo42
author_rank: Super Contributor
timestamp: November 18, 2021, 08:55:54 am
content: If I could get her indoors on the exercise bike in the first place that would be a winner even without tapping off any energy
Question smd ceramic capacitor - Page 1
Forum section: electronics / general

author: tiago1986
author_rank: Regular Contributor
timestamp: November 25, 2021, 01:33:04 pm
content: Do small portable electronic devices that use ceramic or tantalum SMD capacitors also need to be used constantly because they have the same problems as long-term stored electrolytic capacitors?

author: wraper
author_rank: Unknown
timestamp: November 25, 2021, 01:42:18 pm
content: No. Electrolytic capacitors should be powered once in a while to prevent insulating aluminum oxide layer from thinning, which may cause excessive leakage current when the voltage is applied after long period without voltage applied. There is no such degradation process with other types of capacitors.

author: tiago1986
author_rank: Regular Contributor
timestamp: November 25, 2021, 02:07:11 pm
content: in electrolytic capacitors after how long stored does it need to be powered? varies a lot from brand, age of the electrolytic capacitor (beginning of the 90's) and soldered in electronic circuit?the same is not necessary in ceramic smd, tantalum, polyester

author: wraper
author_rank: Unknown
timestamp: November 25, 2021, 02:25:56 pm
content: Quote from: tiago1986 on November 25, 2021, 02:07:11 pmThere is no fixed time, and you won't be able to tell from a datasheet how fast they will degrade. If you power for a few hours in a year or two, they should be fine.

author: tiago1986
author_rank: Regular Contributor
timestamp: November 25, 2021, 03:31:30 pm
content: normally I turn them on 1 hour is enough for the total reform of the electrolytic capacitor? I don't know if I use them every month to reduce failures in electrolytic capacitors from the 90's and mounted in electronic circuit

author: Faringdon
author_rank: Super Contributor
timestamp: November 29, 2021, 08:45:35 pm
content: There must be loads of electrolytic capcaitors that get produced, and then end up in storage for 3 years or more, before getting sold.....and they dont have the dates on them, so they probably get sold as though they were knewly made....But you dont hear about products blowing up at switch on....so i actually wonder if this is a ruse by the El cap industry, to get more sales of el caps.I think you do get higher leakage at switch on if theyve been stored for 3 years plus.....but i suspect that with modern el caps, the leakage still isnt that much...and after half an hour its died down to almost nothing.If this leakage current problem was genuine, then you'd have youtube videos of people putting voltage on a 3_year_old plus el cap, and showing its temperature going sky high....but there is no such video.
Overcurrent limiting circuit will damage power module? - Page 1
Forum section: electronics / general

author: Faringdon
author_rank: Super Contributor
timestamp: January 09, 2022, 07:37:31 pm
content: Hi,We are doing a 48V 7A5 PSU with TUNS500F ACDC power module.We want it to limit current if a 10A load is connected, so the contractors made the attached overcurrent circuit as shown. Do you think it will damage the TUNS500F “TRIM” pin, due to >5V experienced on that pin? (>5V on TRIM pin when overcurrent happens)Attached is a representative LTspice sim of the added overcurrent circuit, and a PDF schem of itTUNS500F datasheet (page 8...)https://en.cosel.co.jp/tool/tag/pdf/SFE_TU.pdfPage “TUNS-27” of the below, says TRIM pin should not have >5V applied to it….https://en.cosel.co.jp/tool/tag/pdf/CME_TU.pdf

author: wraper
author_rank: Unknown
timestamp: January 09, 2022, 07:54:16 pm
content: I don's see how playing with TRM necessarily limits the output current. Many loads will simply draw more current if input voltage is decreased, those which contain SMPS in particular. And then current will rise anyway until internal OCP of the module kicks in. Also your internal circuit of the module is completely made up and does not represent the actual circuit even remotely.

author: wraper
author_rank: Unknown
timestamp: January 09, 2022, 08:05:46 pm
content: EDIT: apparently the following is only true for TUNS1200F and TUNS500F is different.Also apparently when TRM voltage is higher than 4.5V, TRM simply stops affecting output voltage at all, and you will simply get 48V at the output.QuoteOn other hand connecting TRM to GND apparently should result in near zero output voltage. Your made up "module internal circuit" suggests an exactly opposite effect.

author: Faringdon
author_rank: Super Contributor
timestamp: January 09, 2022, 09:45:13 pm
content: Thanks , yes i see this info as in your post above...but that is under the heading "TUNS1200F", and we are using the "TUNS500F". So i believe that info is not relevant to us?

author: wraper
author_rank: Unknown
timestamp: January 10, 2022, 09:39:19 am
content: It seems there is no 5V limitation which is only forVTRM of TUNS1200F. However adjustment range of TUNS500F by TRM pin is only +/- 20%, therefore I don't see how it will help you to limit the current. I thought something like that when typed the first post before part of the manual about TUNS1200F confused me.
Wind can propel your sailboat and charge batteries at the same time - Page 1
Forum section: electronics / general

author: Gregg
author_rank: Super Contributor
timestamp: November 19, 2021, 11:38:53 pm
content: A practical and clever system that uses a submerged propeller to provide electricity when under sail and provide propulsion from batteries it charges. It uses a servo motor to change the propeller blade pitch.https://oceanvolt.com/solutions/systems/servoprop-sail-drive/Video (Skip to 12:00 to see the replacement unit being installed)
Power supply for cathodic protection of ship? - Page 1
Forum section: electronics / general

author: Faringdon
author_rank: Super Contributor
timestamp: November 09, 2021, 08:35:21 pm
content: Thanks, when ICCP (impressed current cathodic protection) is done, they dont use just a DC power supply to supply the current...they use a train of half sine current pulses....at about 60Hz or so. This is presumably so that fusing is easier? (or is it for human safety), since fuse arcs will extinguish easier when the current periodically goes to zero.So essentially, you would use an AC output amplifier, and just diode rectify its output? Probably a class B amp so that it was more efficient.Even better, you would use a Class D type switching amplifier, and make it produce a rectified half sinusoidal output current?How much current and voltage would be needed for a big ship needing cathodic protection?(I had no idea before today that big metal hull ships are literally dissolving away if they dont have cathodic protection)

author: richard.cs
author_rank: Super Contributor
timestamp: November 10, 2021, 09:47:06 am
content: Quote from: Faringdon on November 09, 2021, 08:35:21 pmIs this not because this is really simple(/cheap/reliable) to generate from a 60 Hz A.C. supply?

author: Gyro
author_rank: Super Contributor
timestamp: November 10, 2021, 01:03:25 pm
content: Ye Gods, they're not letting him loose on shipping now!Quote

author: penfold
author_rank: Frequent Contributor
timestamp: November 10, 2021, 01:59:19 pm
content: Uncoated steel hulls can typically be 60mA to 400mA per square meter: depending largely on the speed of movement wrt the water, a propeller would have a much higher current density requirement than an area at the stern for instance. Voltages necessary are something like 1-2V to overcome the anode-cathode potential plus the IR drop which depends on all the geometry stuff (number of anodes, age of anodes, temperature, surface bio-growth and water bio-content)... something like a current-controlled 20V supply can be plenty.60 Hz supplies are standard in naval boats, so maybe in merchant vessels also. Rectified LF is also friendlier for EMC with radar sets around.

author: David Hess
author_rank: Super Contributor
timestamp: November 10, 2021, 06:31:27 pm
content: They are just being cheap by leaving out any filter capacitor. Passive lead-acid battery chargers do the same thing and provide only rectified line frequency AC for charging batteries, but not because there is any virtue of pulsed DC over rectified and filtered DC.Lack of capacitor filtering would extinguish arcs more easily, but that is not why they do it.
Any Chevy Volt owners with the "Shift to Park" defect?  - Page 1
Forum section: electronics / general

author: DougSpindler
author_rank: Super Contributor
timestamp: November 06, 2021, 05:43:02 pm
content: GM is having an issue with the Chevy Volt and several other ICE cars where the car can't be powered down after moving the shifter into park. When the shifter is moved to park and power button pressed the message "Shift to Park" is displayed and the car cannot be powered down.Anyone with any GM car having this issue?GM's fix is to add a 100 ohm resister and diode which are in parallel, to the gear shift position sensor wiring harness in series.Link to GM bulletin to fix the issuehttps://static.nhtsa.gov/odi/tsbs/2020/MC-10171895-9999.pdfAnd I'm attaching a picture of the wiring harness someone posted that's supposed to "fix" the issue.Anyone have any idea what the resistor and diode are doing to the circuit?Seems crazy to me that this would "fix" the issue. Your thoughts....

author: f4eru
author_rank: Super Contributor
timestamp: November 06, 2021, 08:37:12 pm
content: could be contact erosion due to an EMC filter cap in the ECU wired to the switch.

author: Gyro
author_rank: Super Contributor
timestamp: November 06, 2021, 09:07:23 pm
content: Quote from: f4eru on November 06, 2021, 08:37:12 pmTo avoid the frustration of duplicated answers, I suggest looking at...https://www.eevblog.com/forum/chat/what-would-adding-a-resistor-and-diode-to-position-sensor-switch-circuit/