hybridfree/eevblog-posts huggingface dataset:
Power supply solution for a portable radio case - Page 1
Forum section: electronics / general

author: oh2ftu
author_rank: Regular Contributor
timestamp: June 04, 2022, 02:21:38 pm
content: I've built a pelicaseclone which includes a few bits and bobs. However, having a few different boxes for the PSU arrangement has resulted in a lid that's too heavy. It'll tip over :-DI'm looking for a solution that would provide the following features:100-230VAC input8-40VDC (ie. 12V and 24V vehicular power) with reverse polarity protection/indicationAutomatic input changeover6x protected 12V out (max 3 Amps)Total output somewhere around 100-120 WPossibly a connection for a battery (could be a separate connection one of the 12V outs)And also, should not break the bank. This little endeavour has already got expensive enough.I've attached a pic.What's included in the pic:Top left, fuse box with minus railTop right, 12V PSUSilver box: 8-40VDC -> 12VDCThe Wetech chargers take 10-40V (ish)The battery charger on the lower case, to the left, is 12V only (hence the 12V buck-boost)
ETD59 distributed gap core set with AL=250 - Page 1
Forum section: electronics / general

author: Faringdon
author_rank: Super Contributor
timestamp: June 19, 2022, 10:10:34 pm
content: Hi,Do you need two of these for AL=250. or one and the other half ungapped?ETD59 ferrite with Distributed gap for AL=250...https://www.digikey.co.uk/en/products/detail/epcos-tdk-electronics/B66397Q0250K187/15195197From product vid it looks like two of the gapped together?..but that differs on what it was with the old standard gapped cores.https://www.digikey.co.uk/en/product-highlight/e/epcos/distributed-gap-ferrite-cores

author: jonpaul
author_rank: Super Contributor
timestamp: June 20, 2022, 10:35:31 am
content: two make a pairno need, use sheet gap

author: Andy Watson
author_rank: Super Contributor
timestamp: June 20, 2022, 10:59:12 am
content: The TDK datasheet that digikey provide states "magnetic characteristicsper set". I would interpret that to mean two identical half-cores.

author: jonpaul
author_rank: Super Contributor
timestamp: June 21, 2022, 10:13:01 am
content: gapped cores are always sold by the set not the piece.Beware of 38..85 weeks lead time on many Ferrite core OEM parts, eg NiCeria, TDK, etc.Contact your local importer or disty for OEM orders.Retail small parts houses like Mouser, DK may appear to list parts but you may find them impossible to obtain.Jon
Coin Cell battery Models - Page 1
Forum section: electronics / general

author: Zenwizard
author_rank: Regular Contributor
timestamp: May 03, 2022, 01:15:21 am
content: I had a request to make a few battery models for anyone that has a battery simulator. This is from an energiser 2016 cell. I have some 1220's and 2477's on the way. This was done on a 2450 SMU. I figured I would share the data here as well. If there is more interest or more requests let me know.Zen

author: Zenwizard
author_rank: Regular Contributor
timestamp: May 09, 2022, 02:24:53 am
content: Here is the battery model for the 2477. The raw data is a little large for this forum but can be found here:https://www.patreon.com/posts/battery-model-66171112even though this is a Patreon link this post is open to all no subscription needed.

author: Zenwizard
author_rank: Regular Contributor
timestamp: May 15, 2022, 02:09:11 pm
content: Adding the data for the 1220 coin cell to the list. This one had a surprisingly high ESR I need to drop the burn down current to 1mA as apposed to 5mA. And I still ran in to an ESR of over 200 Ohms.

author: SolidBanks
author_rank: Contributor
timestamp: May 20, 2022, 04:31:33 am
content: Will you be making a youtube video discussing these?

author: Foxxz
author_rank: Regular Contributor
timestamp: May 21, 2022, 03:41:53 am
content: Quote from: SolidBanks on May 20, 2022, 04:31:33 amYea I'm interested as well.

author: rubidium
author_rank: Regular Contributor
timestamp: June 01, 2022, 01:44:45 am
content: I'd be interested in the 2477N, which can deliver a higher current than the 2477.Jim
24v , 48v - pulling 12v some loads  - Page 1
Forum section: electronics / general

author: KD0CAC John
author_rank: Frequent Contributor
timestamp: May 24, 2022, 05:38:00 pm
content: A lot of what is available these days seems to be 24v , 48v systems - batteries etc.I am looking to redo an RV system - most loads are 12vdc & 120vac .Most of the better components / systems seem to be 24v-48v - and inverters set to either of these voltages .I like the idea of higher voltage for typical reasons - but still especially with RVs , 12vdc .What I have found look to be best gear for price - EG4 inverters and rack battery Lithium EG4 .So the question is - most efficient way to supply 12v loads ?A 2nd preference low RF noise - using for ham radio ?

author: f4eru
author_rank: Super Contributor
timestamp: May 24, 2022, 07:25:25 pm
content: best option is to exchange the heater resistors for big resistive heater loads, and to get a buck converter for all the small loads.Not sure if the conversion is worth it...Check your LED lights if they could support 24V out of the box.

author: KD0CAC John
author_rank: Frequent Contributor
timestamp: May 24, 2022, 07:34:17 pm
content: Do not use heater resistors .Lighting , furnace / propane / fan 12v , water pump , fridge / propane 12vdc & 120vac .Then inverter for AC cooling .I also have 2 Honda EU2200i - that are setup for parallel - 4400 watts surge .Most of my solar panels are 24v .My last system was 12v with inverter & lead batteries , Ran all loads , including air conditioning and never went below 50% discharge .

author: Simon
author_rank: Unknown
timestamp: May 29, 2022, 09:05:16 pm
content: generally when stepping up the bigger the step the worse the efficiency as the currents drawn at the lower voltage are large. So starting with 48V is always better than 12V as it means that 1/4 the current is required for the same power.You should be able to get a step down converter for the 12V stuff, you could run a separate 12V battery system? I'm not sure why you worry about RFI on your 12V conversion, I'd be more worried about the garbage you inverter is causing unless you have a really good inverter that is not one of the cheap ones.

author: KD0CAC John
author_rank: Frequent Contributor
timestamp: May 29, 2022, 09:38:12 pm
content: Well the battery / inverter I mentioned are some of the best for the price currently available , as far as I know , I have been around & building systems since the late 70s / 80s .Then , again this is for RV service - so adding another battery / voltage , without 12v charging is an issue [ unlike in a building where the space is generally more available ] .RFI - maybe you do not know what ham radio is --- RFI is a big deal - some of the junk electrical stuff CAN totally eliminate ham radio - another reason for 12vdc .

author: Simon
author_rank: Unknown
timestamp: May 30, 2022, 12:06:51 pm
content: well crap converters that have not been tested. Surely a commercial converter that is CE or equivalent marked has been tested as part of the approval and should not be for sale if it fails test.
voltage regulation using TL494 - Page 1
Forum section: electronics / general

author: anshuii
author_rank: Newbie
timestamp: May 27, 2022, 02:31:11 am
content: I am using the given schematic for voltage regulation using TL494. When feedback is not given, that is point A and B are not connected, then I am getting a pulse of 35% duty cycle of 0-12V. But when the feedback is given ( A and B gets connected), then in the output I am getting a 12V DC rather than a pulse even though the positive and negative terminal of error amplifiers have some difference of voltage and there's a sudden large amount of current flow at point C and D that is the primary side of the transformer. I am not understanding why the pulse is getting vanished with 12V dc and sudden large increase in current( i. e from 0.8 A to 1.6 A) in the primary side of the transformer circuit . Is there any blunder in the schematic.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: May 27, 2022, 06:36:53 am
content: Use emitter output instead.Tim

author: anshuii
author_rank: Newbie
timestamp: May 29, 2022, 07:06:29 am
content: still the issue remains same

author: Alex-lab
author_rank: Contributor
timestamp: May 29, 2022, 09:31:21 pm
content: It looks like too high gain for error amplifier (x56). As desired output of 20V corresponds to 2V ref, the 1/10 divider is enough, and further amplification is not necessary.Try to put 1k resistor instead of 56k (pin3).
ICE2HS01G LLC Controller datasheet ambiguities - Page 1
Forum section: electronics / general

author: Faringdon
author_rank: Super Contributor
timestamp: May 28, 2022, 04:11:05 pm
content: Hi,How should you disable the ICE2HS01G?.....by taking the LOAD pin to GND, or taking the VINS pin to GND?...both will disable it, but which way is best?Also, page 8 says if CS (current sense) pin voltage is below a certain level, it will go into skip mode...but surely that cant be true?.....its an LLC controller, and the sensed current goes to zero at every switching period, due to the sinusoidal current in the primary.ICE2HS01G LLC Controllerhttps://www.infineon.com/dgdl/Infineon-ICE2HS01G-DS-v02_01-en.pdf?fileId=db3a30432a40a650012a458289712b4c
UCC28070A (PFC controller) in light load or near zero crossings - Page 1
Forum section: electronics / general

author: Faringdon
author_rank: Super Contributor
timestamp: May 28, 2022, 11:19:07 am
content: Hi,Please could i ask a "bite-size" version of this here now, rather than the unanswered, bigger version asked previously?So....Could we agree that the bottom waveform on page 36, Fig28, of the UCC28070A datasheet is nonsense?….the pulses don’t even line up with the inductor current shown there in the middle trace. That bottom trace is nonsense…you simply don’t see a waveform like that at the output of the current sense transformer when near the zero crossings.UCC28070A datasheethttps://www.ti.com/lit/ds/symlink/ucc28070a.pdf?ts=1653493319157&ref_url=https%253A%252F%252Fwww.ti.com%252Fproduct%252FUCC28070A
Easy way to wind flyback transformer on ETD29? - Page 1
Forum section: electronics / general

author: Faringdon
author_rank: Super Contributor
timestamp: May 17, 2022, 12:09:24 pm
content: Hi,Can we wind our ETD29 flyback transformer without terminating the windings to the pins? (as attached). We will just terminate to pads which we will put on the PCB.We are very club-handed, we struggle winding transformers.Winding a layer, then taping it, then bringing the wire neatly back across for termination is tricky, and results in too much windings depth on the former.Its only for a prototype board.ETD29https://www.tdk-electronics.tdk.com/inf/80/db/fer/etd_29_16_10.pdf
Using TO247 as a SMD component in offline 30W Flyback? - Page 1
Forum section: electronics / general

author: Faringdon
author_rank: Super Contributor
timestamp: May 16, 2022, 11:19:17 pm
content: Hi,Can we lie a TO247 flat on a big SMD pad, and kind of manually "flood" solder beneath it, and then put a screw through to heatsink on PCB bottom, with thermal vias going through, or will the edge plastic of the TO247 get melted up?....and so we need to use (smaller) D2PAK instead?

author: David Hess
author_rank: Super Contributor
timestamp: May 17, 2022, 10:01:51 am
content: A D2PAK has edge plastic also and does not get melted up. What you are suggesting has been done with TO-220 packages. The problem with the TO-247 package is that the tab is not exposed on top, but I think it could still work.Solder will be extruded through the vias making the surface uneven so something will need to be done about this before attaching the heat sink.

author: TimNJ
author_rank: Super Contributor
timestamp: May 17, 2022, 03:12:39 pm
content: If your goal is to heatsink, then I'd suggest to skip soldering and just use use a thermal pad + M3 screw and nut/washer on the back-side of the PCB.If your goal is to make an electrical connection, sure you can do it by reflowing the solder under it, but I'd generally just try to find the right part in D2PAK or some of the more modern flat/lead-less packages.

author: Gyro
author_rank: Super Contributor
timestamp: May 17, 2022, 06:20:58 pm
content: You say "Using TO247 as a SMD component". How are you going to reliably and repeatably (crop and) form the leads so that they meet the solder pads accurately and give a flat seating plane? This is essential if you are going to successfully use solder paste.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: May 17, 2022, 07:55:19 pm
content: They make a "D3PAK" for that. Though I don't think they're widely available outside of.... IXYS?If you need that much power dissipation, a vertical heatsink is needed. No point trying to force it through a PCB.Tim
MC34063 Buck controller seems too cheap to be true? - Page 1
Forum section: electronics / general

author: Faringdon
author_rank: Super Contributor
timestamp: May 16, 2022, 04:23:35 pm
content: Hi,We need a few Low power Buck SMPS’s…..200mA max output…12v to 5v24v to 16v24v to 12v24v to 5v……so we decided to make a little Buck PCB out of MC34063 controller as attached.This all seems too easy to be true….is there some issue with the MC34063?....its only on/off control.Its literally just a comparator looking at the vout. Plus sense resistor which we will change for each case of vout.MC34063 datasheethttps://www.mouser.co.uk/datasheet/2/308/1/MC34063A_D-2315484.pdf

author: ledtester
author_rank: Super Contributor
timestamp: May 16, 2022, 04:30:48 pm
content: The MC34063 is an old part dating back to the 80's.https://electronics.stackexchange.com/questions/78116/mc34063-switching-regulator-ic-when-was-it-introducedUpdate: Dave did a video on the chip about 12 years ago:EEVblog #110 - Let's Design a DC to DC Switchmode Converterhttps://youtu.be/qGp82xhybs4He goes through the complete design procedure for a step-up converter which involves a complete whiteboard of calculations.Near the end he briefly talks about the MC34063 vs other chips mentioning that they can be easier to design for:https://youtu.be/qGp82xhybs4?t=36m17s

author: T3sl4co1l
author_rank: Super Contributor
timestamp: May 16, 2022, 07:18:36 pm
content: Too cheap to what, what else would you expect from something so crude?Most of the layout area and cost goes to caps and inductors, it's pretty awful.And LDO might be as or more efficient, for some of those ratios.For so many outputs I'd consider a multiwinding transformer, doing up ratios to get it right. That or fewer buck regs with a few LDOs to fill in the gaps if reasonable, but that's probably just reasonable for 16 to 12 here, and only if 12 isn't very much current anyway. Or 24 to 16, if not much current (which might be?).Tim
Inrush management for 4kW  offline PSU? - Page 1
Forum section: electronics / general

author: Faringdon
author_rank: Super Contributor
timestamp: April 30, 2022, 11:10:13 am
content: Hi,Doing a 4kW offline PSU with inrush management. The attached seems to be the smallest circuitry that can do it all in hardware. (LTspice sim and jpeg schem)All it has to do is turn the inrush relay ON after a delay after power up. Also, to re-arm the delay, ready for an ON/OFF/ON restart. Also, to make sure the inrush relay doesn’t unwantedly turn off due to the 24V internal PSU powering down due to undervoltage.Can you think of a lower component count way?

author: Circlotron
author_rank: Super Contributor
timestamp: April 30, 2022, 01:19:47 pm
content: That diode in parallel with the PFC boost inductor...

author: Faringdon
author_rank: Super Contributor
timestamp: April 30, 2022, 01:55:18 pm
content: ...Thankyou...Great Spot!.......youve probably saved me a couple hundred pounds with that....Massive thankyou!..now corrected as attached.

author: Faringdon
author_rank: Super Contributor
timestamp: April 30, 2022, 09:40:13 pm
content: Woops , sorry to come back....ive honed it down a little as attached......but any more simplifications?....Also, some kind of simple manual thing where a manual switch was only "enabled" whenever the caps were full would be fine...as this is only a prototype.

author: Faringdon
author_rank: Super Contributor
timestamp: May 10, 2022, 06:37:52 pm
content: Sorry to come back....Actually, a long , and very robust delay is needed for the delay to switch the inrush resistors out.......has to be robust because an un-limited inrush from 240VAC mains peak into 4m3 will kill the PSU and blow the breakers, as you know....though can you think of how to reduce the component count here?...without using a microLTspice and scm attached.
Variable power supply output protection - Page 1
Forum section: electronics / general

author: crysti
author_rank: Regular Contributor
timestamp: May 22, 2022, 06:19:26 pm
content: Hi guys!What is the simplest output protection for reverse battery connection (blocking reverse input current) on 0-60V/5A variable power supply with two N-Channel transistors?Example BJC polarity protectorhttp://www.geofex.com/article_folders/cheapgoodprot.htmExample single Mosfet protectorhttps://youtu.be/7Tk5ghH_U2sThanks in advance!

author: jonpaul
author_rank: Super Contributor
timestamp: May 23, 2022, 08:02:55 pm
content: séries and shunt diodes, eg Schottky, inside feedback loopj

author: David Hess
author_rank: Super Contributor
timestamp: May 24, 2022, 02:12:51 am
content: Quote from: jonpaul on May 23, 2022, 08:02:55 pmThat is how I do it. At lower currents and voltage, a bipolar transistor can be used for lower voltage drop to do the same thing.Some power supplies have a class-B or class-AB output so that they can also sink some current which helps keep the output voltage lower than the regulated voltage, but a series diode should still be used.

author: jonpaul
author_rank: Super Contributor
timestamp: May 24, 2022, 05:31:18 am
content: Dave, fine HP, Lambda lab variable power supplies have such protection diodes.Faults occasionally blow up the diodes but the power supplies survived.One other protection is an overvoltage crowbar, with an SCR and Zener at gate, in shunt with the output.Jon

author: crysti
author_rank: Regular Contributor
timestamp: May 25, 2022, 07:05:34 pm
content: With diode protection power supplies not survives on reverse connection large capacity battery ex. >70Ah lead acid because sudden increase input currentQuote from: jonpaul on May 24, 2022, 05:31:18 am
Control to Output gain-phase measurement - Page 1
Forum section: electronics / general

author: Magnethicc
author_rank: Contributor
timestamp: May 09, 2022, 02:52:10 pm
content: Hi everyone.I want to know if it is possible to measure the control to output transfer function in real life and if yes then how?In LTSpice I use AC analysis of the small signal model of the DC-DC and then take the ratio of output voltage to error amplifier output.Lets assume I have a this buck converter (in reality I will have a PSFB converter) - attached1) In real life I think to inject a signal at point 4 (I have access to this point) and hook the Frequency Response Analyzer (FRA) at Vb and Vout. Is this a good way to measure the control to output transfer function?2) I would also like to measure the compensator transfer function so I though this time to hook the FRA at FB and Va. again is this a good way to measure the compensator gain?3) a question about the frequency of the injected signal - can I inject a signal with a frequency of 1/2switching frequency and above and get results of meaning? or after 1/2 switching frequency I will get garbage information?Any responses and further information is highly appreciated!
Gate driver for Pulse transformer LLC FET drive? - Page 1
Forum section: electronics / general

author: Faringdon
author_rank: Super Contributor
timestamp: May 06, 2022, 03:05:25 pm
content: Hi,Would the attached (LTspice sim and jpeg scm attached) Half Bridge LLC gate drive method be better done with the IR2183, or the TC4428?I am taking it that the TC4428 would be better?, because it doesn’t have dead time……(during the dead time the pulse transformer would be un-driven, which would be disadvantageous if anything?)(we can’t use LTC1693 as its only got VCC TO 13v, and is too expensive)IR2183https://www.farnell.com/datasheets/48099.pdfTC4428https://ww1.microchip.com/downloads/en/DeviceDoc/20001422G.pdf
battery removable smartphone charger store - Page 1
Forum section: electronics / general

author: tiago1986
author_rank: Regular Contributor
timestamp: May 06, 2022, 08:48:32 am
content: What is the best long-term storage voltage for Nokia BP-5L and Xiaomi BM20 smartphone batteries? I have some original BM20s, others are Chinese and the BP-5L I own are Chinese green labelI will recharge them and store them for long periods

author: NiHaoMike
author_rank: Super Contributor
timestamp: May 06, 2022, 12:55:15 pm
content: Charge to about 3.85V, then place in ziploc type bag with desiccant and store in refrigerator. Allow to warm up to room temperature before reopening bag for use.

author: Gyro
author_rank: Super Contributor
timestamp: May 06, 2022, 01:18:40 pm
content: Quote from: tiago1986 on May 06, 2022, 08:48:32 amAnd so tiago's (to mention just his most recent incarnation) Nokia and Xiami battery obsession resumes once again. You have postedsomany threads and been toldsomany times on this forum!

author: tiago1986
author_rank: Regular Contributor
timestamp: May 06, 2022, 01:27:57 pm
content: 3,75v or 3,80v or 3,85v what is the best for the batteries models for long term storage?

author: MK14
author_rank: Super Contributor
timestamp: May 06, 2022, 01:34:41 pm
content: Quote from: tiago1986 on May 06, 2022, 01:27:57 pm3.70V, assuming the batteries are in Belgium (20 deg C). As, the storage temperature, apparently changes that specified voltage.Source:Quotehttps://batteryuniversity.com/article/bu-702-how-to-store-batteries#:~:text=Lithium%2Dbased,for%20most%20Li%2Dion%20systems.Which is3.80V, if you are charging up to that voltage, see article for details.

author: gnif
author_rank: Unknown
timestamp: May 06, 2022, 01:35:54 pm
content: Banned for continual duplicate posts, enough is enough.

author: MK14
author_rank: Super Contributor
timestamp: May 06, 2022, 01:44:27 pm
content: Quote from: gnif on May 06, 2022, 01:35:54 pmAlthough, I and others here, can answer question(s). Like I did, above.If they are NEVER satisfied with any answers, and will keep on posting the same question, again and again. I suspect, you are doing the only thing we really can do.Really, they should just type a question like that into google. Find a decent article/solutions and just stick with it.
UCC28070A used for single PFC stage? - Page 1
Forum section: electronics / general

author: Faringdon
author_rank: Super Contributor
timestamp: May 05, 2022, 11:55:32 pm
content: Hi,We are doing a dual interleaved PFC for 2kW using UCCC28070A.....just to check we're going the right way, we just want to do a proto PCB with just one PFC to start off.....but will this upset the UCC28070A controller?....the datasheet doesnt allude....UCC28070Ahttps://www.ti.com/lit/ds/symlink/ucc28070a.pdf?ts=1651725193988&ref_url=https%253A%252F%252Fwww.google.ru%252FI mean, the Current error amplifier for the unused one will rail high...but the block diag on page 13 doesnt suggest this is a fault instigator?The UCC28070A only has a single multiplier....but that shouldnt matter? If the vout gets into regulation then thats all it should care about?
TO247 NFETs generally slower than TO220 NFETs? - Page 1
Forum section: electronics / general

author: Faringdon
author_rank: Super Contributor
timestamp: April 21, 2022, 03:46:24 pm
content: Hi,Its often said that TO247 NFETs are generally slower than TO220 NFETs?But does this not apply in the case of SiC?...Because in these two similar Rds(on) SiC NFETs, it doesnt appear to apply...Crss is actually lower in the TO247, so are the other junction capacitances...TO247 Sic NFEThttp://www.genesicsemi.com/sic-mosfet/G3R160MT12D/G3R160MT12D.pdfTO220 Sic NFEThttp://datasheet.pnjsemi.com/datasheet/MOS/P3M06120T3.pdf

author: Doctorandus_P
author_rank: Super Contributor
timestamp: May 05, 2022, 10:04:25 pm
content: TO247 is bigger and more expensive than TO220, and thus it's only used for higher power devices.This means larger dies, and larger features (or more in parallel)So if both are Si, then TO247 is likely to have a bigger gate capacitance.You can't directly compare Si and SiC devices on such simple terms.It may even fail miserably with just Si parts.I think there are now 6 "generations" or so of MOS-fets and their properties have changed quite a bit over the last 40 or so years.And of course there are lot's of different FET's because different customers want different properties. some want low Rds-on, others want a high voltage capability, others need high switching speed.But to me the question itself does not make much sense.Picking out a single property out of many and trying to draw conclusions from that is not my cup of tea.
48v input 5v 1aout smps modification idea needed - Page 1
Forum section: electronics / general

author: Tapanaa
author_rank: Newbie
timestamp: May 05, 2022, 01:18:20 pm
content: I need a guide to modify a smps to run on 48v dc input. Or Is it possible to modify off the shelf dc dc buck converter to run on more than 40v dc. I have several Lm2596 boards which has maximum 40v input specs. I need output 5v 1A.

author: John B
author_rank: Frequent Contributor
timestamp: May 05, 2022, 01:47:16 pm
content: LM2596 comes in a high voltage version designated LM2596HV. There's also plenty of buck converters that go up to ~80V.
90W offline Flyback with all PTH components? - Page 1
Forum section: electronics / general

author: Faringdon
author_rank: Super Contributor
timestamp: April 28, 2022, 08:56:05 am
content: Hi,Doing a 90W flyback off 400Vdc, 60V, 1.5A out. 30kHz.Its all in PTH. Not even SMD for the controller.Do you think this will be ok noise-wise? We are going to damp the FET turn on and off to reduce noise. Also, there will be a current sense filter….but all PTH.Ive never done this power level in all PTH before….do you know if its workable?

author: Faringdon
author_rank: Super Contributor
timestamp: May 02, 2022, 02:47:15 pm
content: Also,What about a TNY28x 15W offline flyback supply with vin = 400vdc.....vout = 24v...lunacy to try it with all PTH?TNY28xhttps://www.power.com/sites/default/files/documents/tinyswitch-4_family_datasheet.pdfThe below shows all PTH with TNY28x for 20W....https://www.power.com/sites/default/files/documents/rdr295.pdf...but maybe it gave problems?I would think with PTH offline SMPS, you need access to the primary current sense filter, and to the series gate resistor, so that you can de-noisify it?.....and preferably access to change (reduce) the fsw so you can damp switching transition without getting too much switching loss?The RDR-295 flyback has a Big Np/Ns of 52/3.....this means it operates in DCM, or very close to it, at all Vin. This is believe is to avoid noisy CCM operation, which may possibly overcome it with noise in the all-PTH design. (?) They can get away with Np/Ns = 52/3 because vout is only 5V...which means 52/3 only reflects back 98V to pri..............until i get replies from power.com, i will have to assume that 24Vout and 15W is a no-go for LNK28X, due to the noise. 52/3 for example, would reflect back 416V to pri....and since the TNY28X is only 725V......its going to cause problems.....oh well.........back to the UCC28C43.
company to be aware of - Page 1
Forum section: electronics / general

author: m3vuv
author_rank: Super Contributor
timestamp: April 29, 2022, 11:11:46 pm
content: Just a warning to folks,about 6 months ago my ebike battery went up in flames due to over voltage i think when charging it,i thought ok i will fit a smart bms on my next build,with that i ordered a 40a 13s lithium iron smart bms,from a company on ali express galled Mgod,the bms sat in a box for maybe 3 months as i waited for my new 15q 18650 cells to arrive by sea from china,i connected it all up but no coms with the bms via uart or blutooth,also no output from it,i contacted mgod,they said chech wireing etc which i had already done before connecting the bms,they lost my order number and tried to say i hadnt brought it from them,i sent them a screenshot of my aliexpress orders page with the order number etc,they told me the solution was to buy another unit,i refused to as the bms hasnt worked since it came out of the box,i said i will tell my tail on ev forums unless they replace it at there cost,i then get a message saying a ryan has taken over my case,( first time i have heard of a chinaman called ryan!),anyway we seem to be going around in circles yet againe,this has been going on over 6 months now,,my advice is give this dogshit firm a wide berth,will keep you all posted but dont see a good result on the horizon.

author: ebastler
author_rank: Super Contributor
timestamp: April 30, 2022, 05:34:40 am
content: Have you ever triedreadingone of your own posts? A wall of text, all in one sentence. No paragraphs, no periods, no capitalization, not even spaces after the commas. It feels like you are puking onto our screens.I commend the Chinese company for even reading and replying to your messages. And I can't blame them for assuming, based on your writing, that you have no idea what you are doing and have damaged the BMS yourself.By the way, it is very common for Chinese people who interact with western countries to adopt a western first name as an alias. It's a courtesy to their western counterparts to provide a name that is easier to remember and relate to.
PFC controller datasheet doesnt show enough de-coupling? - Page 1
Forum section: electronics / general

author: Faringdon
author_rank: Super Contributor
timestamp: April 28, 2022, 08:59:54 am
content: Hi,Why does the ICE2HS01G LLC controller datasheet avoid insisting that capacitors are put on the Voltage source outputs, and also, why no 100pF capacitors recommended for the many comparator inputs?Neither the schematic on page 4, or pin descriptions on pages 7 and 8, give any mention of the need for these capacitors.Eg VREF and FREQ pins are voltage source outputs, but no capacitors are recommended or shown for them. They do however show a cap on the chip’s Vcc pin.VMC, LOAD, TIMER, VINS, ENA, VRES pins are all comparator inputs, and in a noisy SMPS, these pins would need 100pF de-noise caps on them. Do you know why not shown or recommended?ICE2HS01G datasheet:https://www.infineon.com/dgdl/Infineon-ICE2HS01G-DS-v02_01-en.pdf?fileId=db3a30432a40a650012a458289712b4c
Wolfspeed opens world's First (& Only) Silicon Carbide 200mm Wafer Fab - Page 1
Forum section: electronics / general

author: station240
author_rank: Unknown
timestamp: April 29, 2022, 12:10:58 pm
content: Wolfspeed opening ceremony, mostly stuffy official stuff and interviews with the bosses.Some interesting stuff at 1:08:29Current Silicon Carbide (SiC) fabs are using 150mm wafers, less wasted material when moving to later process.Somewhere in that long video is a still image of the inside of the fab, can't find it at the moment, not much to see.
SiC FETs are not suited to pulse transformer hi side drive? - Page 1
Forum section: electronics / general

author: Faringdon
author_rank: Super Contributor
timestamp: April 26, 2022, 05:03:48 pm
content: Hi,Would you agree, SiC FETs do not lend themselves to pulse transformer hi side drive?The below SiC FET (C3M0120090D) has an abs max Vgs of +19V….and yet Fig 3 on page 3 shows us that you really need 15V gate drive voltage for it.The problem is that Gate drive transformers can’t be highly damped (for obvious reasons)…as such , the gate drive transformer leakage inductance will ring above 15V, leaving you in peril of breaching the +19V V(gs) maximum.So, SiC FETs should be driven by high side supply , supplying a hi side FET driver, would you agree?C3M0120090D SiC FEThttps://assets.wolfspeed.com/uploads/2020/12/c3m0120090d.pdf

author: ahbushnell
author_rank: Frequent Contributor
timestamp: April 26, 2022, 06:26:56 pm
content: I would not agree. You just have to use the correct gate drive. I would not use a transformer. SiC are fast and the transformer will probably not do the job. Note normally the like a negative bias of -5V when they are off. A transformer will not do that. There are gate drive chips that will work.
"Shutdown bus" in offline PSU needs capacitive decoupling? - Page 1
Forum section: electronics / general

author: Faringdon
author_rank: Super Contributor
timestamp: May 31, 2022, 12:53:35 pm
content: Hi,We are doing a 2kW offline SMPS. The LLC converter can be shut down if need be. This is done by pulling down a “shutdown bus” with an open collector transistor etc. This shutdown bus “roams” round on the PCB over the entire primary side, offering the shutdown facility on its way……….because it is such a physically extensive trace, should we put 100pF caps across it and space them out along its length?

author: pardo-bsso
author_rank: Frequent Contributor
timestamp: June 02, 2022, 07:48:41 pm
content: Why 100 puffs and what would that do to the input response?Why distributed?

author: Faringdon
author_rank: Super Contributor
timestamp: June 02, 2022, 10:21:06 pm
content: QuoteThanks...if more then the pull down suddenly discharging the caps would create current spikes....that being bad for emc...Distributed so as to reduce the size (area) of the biggest current loops, without spending too much money on caps.
SiC FETs are  overly sensitive to ESD damage? - Page 1
Forum section: electronics / general

author: Faringdon
author_rank: Super Contributor
timestamp: April 26, 2022, 10:38:05 am
content: Sic FETs always have less Vgs voltage maximums than Si FETsEg C3M0060065D (SiC) vs FCH104N60 (Si) is typicalDo you agree, this translates to a lesser ESD damage immunity for the SiC FETs?Also, the SiC FET is far less likely to incorporate internal Zener/diode gate-source clamping, (-this again, results in even worse ESD immunity for the SiC FET) because with SiC and its low Vgs(max), the Zener voltage would have to be too close to the gate drive voltage.Also, in my experience with SiC FETs, I have found them getting killed by any handling at all, without absolute full ESD protection, whereas with Si FETs, you can get away with it.SiC is overly sensitive to ESD damage…would you agree?C3M0060065D datasheet (SiC)https://assets.wolfspeed.com/uploads/2020/12/C3M0060065D.pdfFCH104N60 datasheet (Si)https://www.micro-semiconductor.com/datasheet/f7-FCH104N60.pdf
Best way to wind hi side gate drive transformer? - Page 1
Forum section: electronics / general

author: Faringdon
author_rank: Super Contributor
timestamp: April 26, 2022, 04:17:23 pm
content: Hi,Going to do a 1:1 hi side gate drive transformer by bifilar winding 39 turns of 0.2mm TEX-E TIW round a E20/10/6 core former. So that’s 3 layers.How will the leakage inductance compare with just sandwich winding it? Ie secondary between two series primary halves as follows…P1 20 turns 0.35mm TEX-E (1 layer)S 40 turns 0.35mm TEX-E (2 layers)P2 20 turns 0.35mm TEX-E (1 layer)Will the interwinding capacitance be excessive with the bifilar wound one?E20/10/6 ferrite core:https://www.tdk-electronics.tdk.com/inf/80/db/fer/e_20_10_6.pdfTEX-E wire:https://www.furukawa.co.jp/tex-e/en/product/texe_series.html

author: T3sl4co1l
author_rank: Super Contributor
timestamp: April 26, 2022, 09:21:11 pm
content: If it's TIW, what's the point of section winding? Just twist pairs and go.Tim

author: Faringdon
author_rank: Super Contributor
timestamp: April 27, 2022, 08:49:34 am
content: Thanks yes, the bifilar winding definetely gives less leakage inductance than sandwiching?...i hear bifilar winding gives more capacitance between pri and sec?

author: T3sl4co1l
author_rank: Super Contributor
timestamp: April 27, 2022, 12:39:16 pm
content: sqrt(LL/Cp) = Zoc_0 sqrt(LL Cp)) = l_0 (or something like that)Zo is characteristic impedance, you want low to match the low gate circuit impedance.l_0 (that's lowercase l for length) as in electrical length, winding wire length. c_0 as in speed of light in the medium. It's a transmission line, LL and Cp go up proportionally with length, while their ratio is fixed by Zo.If you need less LL and Cp, use less wire. Usually on a fatter core (more flux per turn --> fewer turns), or with higher density (nanocrystalline).It seems to me Cp is generally overrated for purposes like these. And it can be dealt with through other means like balanced windings, shielding, CMC, etc.Tim
Current sense transformer position in LLC converter? - Page 1
Forum section: electronics / general

author: Faringdon
author_rank: Super Contributor
timestamp: April 23, 2022, 11:42:07 am
content: Hi,Do you agree, B is better than A for current sense transformer position?A would be madness as its in an extremely high dv/dt switching node?(LTspice and Jpeg attached)

author: ahbushnell
author_rank: Frequent Contributor
timestamp: April 23, 2022, 10:04:33 pm
content: The circuit you are measuring has a DC component. Therefore you can't use a transformer unless you just want to look at the AC component.What do you plan to do with this information? Will this be for a current mode control? .Andy

author: Faringdon
author_rank: Super Contributor
timestamp: April 23, 2022, 10:55:12 pm
content: Hi,Its for overcurrent shutdown.There is indeed a dc component, (at least in the LTspice sim of the top post) but its only 10mA, and the peak current is around 16A.Mind you, i dont know where this comes from, the series capacitors should remove any DC?

author: T3sl4co1l
author_rank: Super Contributor
timestamp: April 24, 2022, 11:51:03 am
content: B
LLC converter with overvoltage ringing to output diodes? - Page 1
Forum section: electronics / general

author: Faringdon
author_rank: Super Contributor
timestamp: April 20, 2022, 08:06:25 am
content: Hi,Doing LLC with Vin = 390VDC and Vout = +/-180Vdc at 4kW.The simple 2 diode output rectifier suffers high ringing voltage on the output diodes when the respective diode switches off.However, the full bridge output LLC suffers none of this, and as such, lower voltage diodes can be used. Would you agree that overall, the "full bridge output" approach is best?(apart from different cases when Vout is low and Iout is very high, granted)Attached shows the LLC with full bridge and simple 2 diode bridge in LTspice and jpegThe Full Bridge output LLC suffers absolutely no output overvoltage ringing at all.Its noteable that when the 2-diode output LLC has a diode turn off, then there's nowhere for the leakage inductor current to go.........whereas with the full bridge LLC, there is actually a path for the leakage inductor current after a diode turns off......this is i believe what eradicates any ringing in the full wave output LLC?Incidentally, page 12 of this depicts the two diode output types, but doesnt mention ringing...https://www.infineon.com/dgdl/Application_Note_Resonant+LLC+Converter+Operation+and+Design_Infineon.pdf?fileId=db3a30433a047ba0013a4a60e3be64a1

author: jonpaul
author_rank: Super Contributor
timestamp: April 22, 2022, 06:40:04 am
content: Farrington, your simulations may not be realistic. Did you actually build these yet?I also suggest you check Double Foward topology, and soft switching as solutions.Cheers,Jon

author: Faringdon
author_rank: Super Contributor
timestamp: April 22, 2022, 08:55:39 am
content: Thanks, but i think its to do with the coupling between the secondaries....if we are just using 2-diodes output, then coupling between the two secondaries has to be very good, or else there is big spikes on the output diodes.....this problem doesnt happen if you use the 4-diode output.

author: jonpaul
author_rank: Super Contributor
timestamp: April 22, 2022, 09:39:57 am
content: The Llkg is minimal for a bifillar secondary in a two windings designAt high current foil can Also he interleavedJon

author: Faringdon
author_rank: Super Contributor
timestamp: April 22, 2022, 11:00:55 am
content: QuoteThankyou kindly, i was worried you'd say this, because these are great suggestions, but expensive and manually awkward to realise.As a hobbyist, i cant realistically afford interleaved foil methods.Also, the secondarys we have are each several strands of 7/0.3mm TEX-ELZ, and if we bifilar wind them, the bobbin height will be exceeded.So your suggestions are great, but run us over our cost budget....as we would need mitigating methods to do as you kindly say, which just run our costs a lot higher.Malheuresement, we will just have to realise the two split outputs with its own 2kW LLC, each with a single secondary coil, and use a full bridge diode output.
How do you search bootstrap drivers with V(output) up to 25V? - Page 1
Forum section: electronics / general

author: Faringdon
author_rank: Super Contributor
timestamp: April 22, 2022, 12:07:21 pm
content: Hi,We wish to do the gate drive connection as in Fig 10.3, page 31 of the UCC21520 datasheet.However, UCC21520 is expensive, and we don’t need Disable and Dead time pins. So, how, in eg digikey, can we do a search for such an isolated bootstrap gate driver which has a V(boot) to V(sw) power supply capability of 25 to 30V minimum? Digikey doesn’t allow you to do this search pick.(We also dont need 600V isolation, as this chip will be sat in the high side, with a hi side power supply to power it, and the gate drive signal will be sent up with a signal pulse transformer. However, the signal input does need isolation from the output, so that we can have the negative output rail)UCC21520 datasheethttps://www.ti.com/lit/ds/symlink/ucc21520.pdf?HQS=dis-mous-null-mousermode-dsf-pf-null-wwe&ts=1650625810270&ref_url=https%253A%252F%252Fwww.mouser.co.uk%252FEDIT: Aah, digikey has a section called "isolators gate drivers" and this appears to have many eg UCC5320Ehttps://www.ti.com/lit/ds/symlink/ucc5310.pdf?HQS=dis-dk-null-digikeymode-dsf-pf-null-wwe&ts=1650604285148
Gate drive: Why is "Active Miller Clamp" function only for IGBT's? - Page 1
Forum section: electronics / general

author: Faringdon
author_rank: Super Contributor
timestamp: April 24, 2022, 01:01:16 pm
content: Page 10 of the following discusses the “Active miller clamp” function of this high side gate driver IC....https://www.infineon.com/dgdl/Infineon-1ED020I12-B2-DataSheet-v02_02-EN.pdf?fileId=db3a304333227b5e013344bf16f84ca6Why does it only refer to IGBT’s as being benificiarys of the “Active miller clamp” function?Also, which is better to prevent spurious Miller turn on of a SiC FET?.....a)…Using a Bipolar gate driveb)….Using a Unipolar FET drive and an "Active Miller Clamp" function.c)….Using a Unipolar FET drive and a PNP turn off circuit

author: David Hess
author_rank: Super Contributor
timestamp: April 24, 2022, 06:27:39 pm
content: Quote from: Faringdon on April 24, 2022, 01:01:16 pmPower MOSFETs are less likely to be used in a high voltage application where an active miller clamp is necessary, but it applies to power MOSFETs just as much.QuoteThe active clamp is necessary when there is an assumption that a series resistance is between the gate drive and the gate, like in your example.QuoteThis is effectively identical to bipolar drive and it requires the same series resistance.
massive jets of flame when CNG bus caught fire - Page 1
Forum section: electronics / general

author: jonovid
author_rank: Super Contributor
timestamp: April 21, 2022, 02:04:06 pm
content: massive jets of flame from a bus fire and no its not an EVhttps://www.theautopian.com/why-this-natural-gas-powered-bus-shooting-gigantic-columns-of-flame-is-an-example-of-safety-tech-at-work/Battery powered EV bus bursts into flames - There is no way to put the fire outhttps://www.bitchute.com/video/vCiNDYNDTV3O/

author: f4eru
author_rank: Super Contributor
timestamp: April 21, 2022, 07:07:57 pm
content: Funny how people spread false information.Yeah, CNG burng and venting happens.

author: Gyro
author_rank: Super Contributor
timestamp: April 21, 2022, 07:16:58 pm
content: You'd have thought that they would have put baffles on the side vents (if that's what they are) to deflect any flames upwards. Horizontal flamethrowers are never going to end well!CNG has its advantages, but its rapid expansion on release isn't one of them.

author: Marco
author_rank: Super Contributor
timestamp: April 21, 2022, 08:29:45 pm
content: LNG seems a lot safer.

author: james_s
author_rank: Super Contributor
timestamp: April 21, 2022, 08:48:59 pm
content: Isn't it essentially the same thing? LNG is CNG that is stored under a high enough pressure that it liquefies. It's still going to vent as a gas if it gets too warm.

author: Marco
author_rank: Super Contributor
timestamp: April 21, 2022, 08:55:52 pm
content: You can't compress methane to a liquid at room temperature. LNG is cryogenically stored at atmospheric pressure, it's in a dewar and not a pressure tank. So it needs to boil off to create gas and I don't see that happening as fast as the gas escaping that CNG tank.

author: station240
author_rank: Unknown
timestamp: April 22, 2022, 10:55:38 am
content: Quote from: Gyro on April 21, 2022, 07:16:58 pmAh there are reasons for the 3 different venting directions.See if you vent all the gas/flames straight up, that in itself creates additional safety issues.Namely initiating collapse of overhead bridges and tunnels. Plus you have to consider what happens if the bus rolls over and one or more vents are obstructed or crushed shut.So the gas vents in 3 directions, left, right, up. The two sides ones are high on the roof, so still allow bus passengers to escape.

author: tszaboo
author_rank: Super Contributor
timestamp: April 22, 2022, 11:06:20 am
content: Quote from: Marco on April 21, 2022, 08:29:45 pmThe issue with LNG for this purpose is that you cannot keep the tank empty. When the tank is empty, it's heat capacity is much less, it heats up much faster and there is always residual LNG left in the tank. At that point the pressure goes up and vents. LNG is fine for large tanks, that have maintenance scheduled, but I'm not sure if I would like to stick it on a bus. Public transport is known to have issues with simple maintenance, like cleaning, not issues where the lack of filling would end in a spill or fireball.
Low power Flyback SMPS looks to good to be true? - Page 1
Forum section: electronics / general

author: Faringdon
author_rank: Super Contributor
timestamp: April 20, 2022, 06:35:33 pm
content: Hi,Need isolated 15V, 60mA. (not mains full isolation type thing though...just a supply for a high side gate drive, for a Half Bridge LLC FET switching off 400V)The attached looks perfect......works in the attached LTspice sim...i bet the real thing doesnt!?Can you see any gremlins?

author: Jay_Diddy_B
author_rank: Super Contributor
timestamp: April 22, 2022, 11:43:16 am
content: Hi,Try this:I have removed a lot of unnecessary parts and reduced the cost.Model attached.Jay_Diddy_BFlyback 24vin to 15vout JDB.asc(5.88 kB - downloaded 35 times.)

author: Faringdon
author_rank: Super Contributor
timestamp: April 22, 2022, 12:09:30 pm
content: Thankyou very much indeed for that, much appreciated.The thing about that is, what happens say if both outputs go no_load.(Apologies, i should have said there's an interest in the no load situation)I think the LT1245/UCC28C45 just keep switching on very low duty, and pump the vout up and away

author: tom66
author_rank: Super Contributor
timestamp: April 22, 2022, 09:07:13 pm
content: If you only need 60mA, stick a zener across the output to provide some load and prevent the output floating too high.Adjust the current limit so the converter begins to chirp as the zener conducts.