hybridfree/eevblog-posts huggingface dataset:
Replacement part for an RS-485 isolated transceiver - Page 1
Forum section: electronics / beginners

author: Freshman
author_rank: Regular Contributor
timestamp: October 01, 2024, 11:47:46 am
content: Currently I am using this (IL4822) RS-485 isolated transceiver (https://www.nve.com/Downloads/il4685.pdf) for my application and it is out of stock.This is the closest alternative (ISO1452BDWR) that I could find (https://www.ti.com/lit/ds/symlink/iso1452.pdf?ts=1727783052393&ref_url=https%253A%252F%252Fwww.ti.com%252Fproduct%252FISO1452%252Fpart-details%252FISO1452BDWR%253Futm_source%253Dgoogle%2526utm_medium%253Dcpc%2526utm_campaign%253Docb-tistore-promo-asc_opn_en-cpc-storeic-google-in%2526utm_content%253DDevice%2526ds_k%253DISO1452BDWR%2526DCM%253Dyes%2526gad_source%253D1%2526gclid%253DCj0KCQjwu-63BhC9ARIsAMMTLXR1xWzN_o18AoKFSpmAKJmsUYui8G7QEL30W4kPgP3XPj7EYOik59saAjHCEALw_wcB%2526gclsrc%253Daw.ds)Can someone tell me whether my selected alternative is fine? Or is it wrong? Any suggestions on the other possible available alternates for IL4822 are welcome.

author: PGPG
author_rank: Frequent Contributor
timestamp: October 01, 2024, 12:40:39 pm
content: Your original IC have integrated isolated DCDC converter while your alternative IC don't have it.

author: Freshman
author_rank: Regular Contributor
timestamp: October 01, 2024, 02:06:34 pm
content: Thank you. So, just a clarification.Could you please suggest an alternate part that would be a good replacement for the Original part? I tried in Digikey and mouser but couldn't find one correctly

author: PGPG
author_rank: Frequent Contributor
timestamp: October 01, 2024, 03:28:55 pm
content: If I knew the replacement part I would write, but to search it I have no time.When 20 years ago I was using isolated RS485 I made it with 3 elements:- signal isolator (one from ADuM serie),- DCDC isolated converter,- standard RS485 transceiver.Never used part like you have.
Replacement part - Page 1
Forum section: electronics / beginners

author: dcbrown73
author_rank: Regular Contributor
timestamp: April 14, 2021, 05:54:55 pm
content: Hi all,A have a friend who has a Samsung Plasma TV. The power supply is not functioning and it appears there is a thermistor that is burned on it. The PCB marks it as a NT801S. The only places I can find these are mainly in the UK.Is there an alternative part / part number in the US that anyone would know of?

author: ledtester
author_rank: Super Contributor
timestamp: April 14, 2021, 07:08:33 pm
content: Following these links:-https://riddledtv.com/forums/samsung-hcn653w-turned-on-briefly-then-shut-off-t1195.html-https://riddledtv.com/forums/samsung-hcn653w-turned-on-briefly-then-shut-off-t1195,start,10.html-https://www.searspartsdirect.com/product/3g1yoy321u-0057-528/id-1404-001195leads to this Amazon listing:https://www.amazon.com/Samsung-1404-001195-Thermistor-Ntc/dp/B001ICXHRW

author: bdunham7
author_rank: Super Contributor
timestamp: April 14, 2021, 08:53:12 pm
content: Looks like a 10 ohm 6A max continuous current NTC thermistor:https://datasheetspdf.com/pdf-file/815069/EXSENSE/NTC-10D20/1This ought to work:https://www.mouser.com/ProductDetail/Semitec/10D2-18LD?qs=wgO0AD0o1vt11uicrhEvow%3D%3Dbut good luck finding stock...

author: Jwillis
author_rank: Super Contributor
timestamp: April 14, 2021, 10:31:36 pm
content: DigikeyMF73T-1 10/8Looks like they have some in stock.
Replacement terminal connectors for lab supply - Page 1
Forum section: electronics / beginners

author: Sigmoid
author_rank: Frequent Contributor
timestamp: August 09, 2013, 07:22:20 pm
content: Hey,I've been all over ebay looking for a good lab supply, and quite a lot of them seem to have gone through a lot, with the terminal connectors broken or missing. Like this one:http://www.ebay.com/itm/BK-Precision-1651A-Triple-Output-DC-Power-Supply-/160765941721Most of these have pretty similar looking sockets, so I'm wondering if there's a generic drop-in replacement for them you can get at Mouser or something.

author: IonizedGears
author_rank: Regular Contributor
timestamp: August 09, 2013, 09:19:47 pm
content: The sockets should just be regular unshrouded banana jacks if this goes by the industry standard.

author: Matje
author_rank: Regular Contributor
timestamp: August 09, 2013, 10:26:12 pm
content: Quote from: Sigmoid on August 09, 2013, 07:22:20 pmIt's likely that you can get replacements.To find out what exactly to get you need to have the lab supply in hand, tear it down and check the backside connection and the mounting style, as these are not quite standard.So there is a bit of risk to it. Speaking of risk - I'm not sure it would be a good idea to buy a device with broken off parts (quite sturdy parts to boot) in the first place.

author: Sigmoid
author_rank: Frequent Contributor
timestamp: August 10, 2013, 12:05:57 am
content: Quote from: Matje on August 09, 2013, 10:26:12 pmYou may be right.Those have likely been through hell and back. I guess I'll get a small Chinese Volteq or similar new.
Replacements for old relays - Page 1
Forum section: electronics / beginners

author: Dan112123
author_rank: Newbie
timestamp: April 14, 2013, 02:18:19 pm
content: Hey guys does anyone where I could get replacements for ATQ229 and ATK109. I have an old serial controller and one of the relays died on it. The problem is I can't find any those old relays anywhere and I don't know if anyone makes analogues that I can just pop in.

author: Dan112123
author_rank: Newbie
timestamp: April 14, 2013, 06:27:26 pm
content: I found ATQ229 on ebay, that is not a problem. But the really that I really need is ATK109 5V. That's the relay that died.Panasonic has discontinued those according to their web site.http://pewa.panasonic.com/components/relays/signal-relays/tk/The question is how does one find an analogue/replacement for those?

author: SeanB
author_rank: Super Contributor
timestamp: April 14, 2013, 07:04:32 pm
content: Try RS or other suppliers, they may still have stock, as they were only discontinued less than a year ago. If they do and you buy, buy enough to replace all the relays if the stock is enough.

author: Dan112123
author_rank: Newbie
timestamp: April 15, 2013, 01:42:54 am
content: Ye I've tried all major suppliers couldn't find one.
Replacemnet for DS8863 - Page 1
Forum section: electronics / beginners

author: Ziltoid
author_rank: Contributor
timestamp: July 28, 2013, 07:29:02 pm
content: Hi,For the repair of an older dmm i need to replace the octal inverter. Its used as a LED Driver (DIP 18 Package). Maybe someone knows a replacement, or some tips where to search! Thanks in advance.Datasheet

author: ddavidebor
author_rank: Super Contributor
timestamp: July 28, 2013, 08:18:13 pm
content: It's a lot of not

author: Paul Price
author_rank: Super Contributor
timestamp: July 28, 2013, 08:54:22 pm
content: Not so! Lotsa 2b got.http://www.ebay.com/itm/NS-DS8863N-DIP-18-LED-Display-Driver-/400505982936?pt=LH_DefaultDomain_0&hash=item5d40044fd8

author: edavid
author_rank: Super Contributor
timestamp: July 28, 2013, 08:58:26 pm
content: You could patch in a couple of ULN2003As, otherwise just buy one on eBay.

author: Ziltoid
author_rank: Contributor
timestamp: July 29, 2013, 12:12:51 pm
content: Thanks for the advice, i bought some on ebay, but it will take a take a month until they arrive, and i didnt want to wait that long.

author: edavid
author_rank: Super Contributor
timestamp: July 29, 2013, 03:12:11 pm
content: Quote from: Ziltoid on July 29, 2013, 12:12:51 pmWire a couple of ULN2003As to a DIP header then?
Replacing 18500 Li-ion battery with 18650 - Page 1
Forum section: electronics / beginners

author: sirish
author_rank: Newbie
timestamp: January 24, 2017, 12:11:36 am
content: Hello all,Can anyone shed some light on 18650 and 18500 batteries ? I'm upgrading 18500 battery to a 18650 one ? Space isn't a constraint and I need the battery to last longer. From my research I found that 18500 can max go upto 1700mAh. And I saw 18650's go upto 3500mAh. So the voltage ratings being the same, I'm assuming it'll run for double the time. Is that a fair statement ?The 18500 battery I have is Sanyo UR18500FK. The 18650 I'm considering is Panasonic NCR18650B. Also looks like battery chemistries are different and I don't know if I should focus on that.Thanks in advance !!Sirish

author: kiran_shrestha
author_rank: Regular Contributor
timestamp: January 24, 2017, 12:25:08 am
content: Hey !! I searched and found out the battery chemistries are same both Li Ion.. si in my case it would be interchangeable, and talking of extra 150mAh, I think wont do no harm if your project is not so critically depended on battery charging.

author: james_s
author_rank: Super Contributor
timestamp: January 24, 2017, 05:45:16 am
content: 18650 and 18500 are form factors, not battery types. These are 18mm diameter and 65mm/50mm long respectively. Most are Li-ion although other types have been made in that size. Assuming li-ion you'll be fine to replace one with the other.

author: Brumby
author_rank: Unknown
timestamp: January 24, 2017, 05:49:49 am
content: This:Quote from: james_s on January 24, 2017, 05:45:16 amThat type of nomenclature is also used in 'button' cells - eg CR2032 is 20mm diameter and 3.2mm thick.

author: Rick Law
author_rank: Super Contributor
timestamp: January 24, 2017, 06:18:33 am
content: Quote from: sirish on January 24, 2017, 12:11:36 amThe capacity rating 1700mAH means it can provide 1mA for 1700 hours or 1700mA for one hour at the state voltage. In real life, that is never true. Typically, the capacity will be reduced when the discharge current is increased. So unless you know at whatcurrentis thatcapacityrated for, you really don't know for sure. What you do know for sure is, their capacity listing is likely just the best case scenario number. When drawn at high current, the 1700mAH battery may end up delivering a lot less.But in general you are right, 3500mAH would indeed be just a bit over twice 1700mAH, approximately.The chemistry in general doesn't mean much as long as it can provide the level of current and voltage you need. Li-PO usually provide a lot higher current than LiIon can. It can also be charged at higher current than LiIon can. But it looks like you are looking at LiIon since you are talking 18650 vs 18500. It does affect the voltage however. Some LiIon chemistry are charged to 4.35Volt and some lower, some LiPO are charged to different voltage also. So yes, it matters as it will affect how high a voltage you can charge them to.Just to be complete, I'll add this: you can use the lower charge-to volt. You can charge the 4.35V battery to just 4.2V and it will work but you loose some capacity.
Replacing 24V bulb with LED in audio amp - Page 1
Forum section: electronics / beginners

author: klausman
author_rank: Regular Contributor
timestamp: May 31, 2025, 02:44:26 pm
content: So I am repairing a Luxman L-215 amp. One of the broken circuits is this power indicator (P.L. 1):(I have deleted some unrelated circuitry, the full schematic is in the attached PDF)Not only was the bulb burnt out, the Zener diode D112 was completely cooked (measure ~1Ohm either direction, and a big scorch mark on the PCB, this thing gothot).As indicated in both the schematic and the parts list, the diode is a HZ20-3, which, as far as I can tell (https://www.renesas.com/en/document/dst/hz-series-datasheet?r=536051) should have a Vz of 20.2~21.1 and a max power dissipation of 500mW. So I ordered one such diode (https://www.digikey.ch/en/products/detail/nexperia-usa-inc/NZX22A-133/2119735), put it in the circuit (no bulb yet, I want to replace that with a 1kOhm resistor and a red LED).I measured the voltage across the diode and its >26V. Granted, the circuit is unloaded (no bulb/LED), but this also made the diode heat up rather quickly. Within ~5m, it measured >100C and seemed to accelerate. I turned off the whole thing to avoid it cooking itself.I also measured the resistor (R153, 300Ohm, 3W), which was okayish (286 Ohms). The schematic-indidcated pre-resistor voltage of 40V is also correct in my circuit, though ever so slightly low (39V and change).The questions are:Is my approach even valid? If not, how can I tweak this circuit to allow for using a low-current (20mA or so) LED?would putting in the LED and resistor produce enough load to drop the 26V to not cook D112?Even if (1) is valid, is there a better approach to replacing this bulb? I really don't want to go back to incandescent because of reliability etc.

author: SuzyC
author_rank: Frequent Contributor
timestamp: May 31, 2025, 06:15:10 pm
content: The 330-ohm R153 is too low a value for a replacement very more bright and efficient low power LED. Simply change the 330 to 2K-1W and the LED will be quite bright but operating well in spec for a LED max current.Nothing else needs to be changed.

author: klausman
author_rank: Regular Contributor
timestamp: May 31, 2025, 06:18:21 pm
content: Quote from: SuzyC on May 31, 2025, 06:15:10 pmThat's what I suspected. Thank you! I'll bet a handful of resistors from the 2K-4K and see which ones work best. My store of >1/4W resistors is low anyway.
Replacing a Defective, Discontinued VFD Module - Page 1
Forum section: electronics / beginners

author: Z. Khalid
author_rank: Contributor
timestamp: October 11, 2023, 09:44:43 am
content: Hello there!What equivalent/successor display module would you recommend using for replacing the discontinued vacuum fluorescent display with the part number M402SD10A from Futaba?

author: dietert1
author_rank: Super Contributor
timestamp: October 11, 2023, 10:19:32 am
content: Did you look here?https://www.sierraic.com/M402SD10A(18 pieces)https://www.lektronix.de/equipment/futaba-corp-m402sd10a/264388(repair)Also there is an offer with 86 pieces on ebay.Regards, Dieter
Replacing a fixed and a adjustable regulator - Page 1
Forum section: electronics / beginners

author: gkmaia
author_rank: Frequent Contributor
timestamp: January 06, 2019, 02:41:32 am
content: I looking for some help replacing a couple regulators. IC 101 and 107 on the schematic attached.First one is a s-81250hg and the closest I found was:https://www.ablic.com/en/doc/datasheet/voltage_regulator/S812C_E.pdfSecond one is a TK11640. I am struggling with this one because it is not fixed. It goes in increments of 0.5 from 2v up to 5v.S-81250HG is here:https://www.digchip.com/datasheets/parts/datasheet/432/S-81250HG-pdf.phpTK11640 is here:https://www.datasheetarchive.com/pdf/download.php?id=6b04dbd83b9c95ca8b5539f6738b79f62a036b&type=O&term=TK1164

author: mvs
author_rank: Frequent Contributor
timestamp: January 06, 2019, 07:31:10 pm
content: Quote from: gkmaia on January 06, 2019, 02:41:32 amThey all are fixed. TK11640 is 4.0V, TK11630 (IC107) is 3.0V, S-81250HG (IC101) is 5.0V...

author: Zero999
author_rank: Super Contributor
timestamp: January 06, 2019, 07:47:08 pm
content: The TK11640 is fixed and is made to the required voltage by the manufacturer.No doubt all of those regulators could be replaced with fixed/adjustable low dropout regulators with a suitable current rating.

author: gkmaia
author_rank: Frequent Contributor
timestamp: January 06, 2019, 09:01:04 pm
content: Thanks guys, those are the ones I found that are the closest ones with matching pins.Sorry for such basic question. I am a beginner and don't want to get it wrong.3v - Tk11630https://www.digikey.co.nz/short/p73f725v - s-81250hghttps://www.digikey.co.nz/product-detail/en/ablic-u-s-a-inc/S-812C50AY-B2-U/728-1066-ND/3609196
Replacing a LiPo battery with NiMh AAAs? - Page 1
Forum section: electronics / beginners

author: RyanT
author_rank: Contributor
timestamp: April 22, 2018, 10:29:09 pm
content: Hey all,I'm in a bit of a bind. It's Sunday evening and I need to fix a 10 year old commercial sensor that I don't have the parts for. The sensor had a "non-user-serviceable" LiPo battery that was soldered and then siliconed on to the board, which was then hot glued to the housing, which was then plastic welded shut. What a pain.The battery was puffed up enough to crack the plastic housing and flex the multi-layer board, one of the leads was badly corroded, and the battery was completely flat. (My strong suspicion is that it was over-discharged and then attempted to charge again.) It was a slightly nerve-wracking trying to cut and pry the battery out without puncturing it.Anyway, it's a 3.7v 250mAh LiPo, with no charging circuitry (that's built into the board, for all the good it did). I don't have a suitable LiPo battery on hand and won't be able to get parts for a couple of days. Would it be OK to use 3xAAA (1.2v NiMH) in series instead? I do not plan to charge them in-situ, just use them as a 3.6v power source until I can get a proper replacement. Or is the charging logic for LiPos OK for NiMH as well? (From what I remember, NiMH are a bit more tolerant, but I'm not sure.)

author: IanB
author_rank: Super Contributor
timestamp: April 22, 2018, 10:38:25 pm
content: I think the operating voltage of the LiPo will be in the range from 4.2 V down to 3.7 V, while the operating voltage of 3xAA NiMH will be in the range of 3.9 V down to 3.3 V. So the NiMH may be a little under voltage, depending on the tolerance of the device. But it wouldn't hurt to try. Or you could try 3xAA alkaline as a temporary fix as long as the device doesn't try to charge them.NiMH cannot be charged with a LiPo charger. NiMH require constant current charging with special end of charge detection logic. Using a CC/CV charging algorithm will be likely to overcharge them unless you set the CV voltage quite low (much lower than the LiPo voltage).
Replacing a microSD card with a flash memory IC - Page 1
Forum section: electronics / beginners

author: DanInvents
author_rank: Contributor
timestamp: December 28, 2022, 01:35:25 pm
content: Hi!I'm currently working on a project where I need to do datalogging and I want to replace a microSD card slot with a dedicated flash memory chip.Adafruit sells modules based on NAND flash memory, and they use the XTSD04G IC. I have found an IC alternative from Winbond, the W25N01GVZEIG. It features the same kind of memory block size as a standard SD card and the pinout functionality is identical to the XTSD04G. Does anybody have experience using these kind of ICs? Could I use the W25N01GVZEIG as a microSD card replacement?Thanks!As attachments you will find the datasheets for the components that I mentioned.

author: mvs
author_rank: Frequent Contributor
timestamp: December 28, 2022, 02:15:33 pm
content: W25N01GVZEIG is just a QSPI NAND flash memory chip and it lacks built-in SD controller.You may still be able to use it in your project, but it is not a 1:1 replacement for a SD-card as XTSD0xG.PS: you can buy SD NAND chips (XTSD01G, XTSD04G, CSNP1GCR01, CSNP4GCR01, MKDV1GCL, MKDV4GCL, ZDSD01G, ZDSD04G) at lcsc.com.

author: DanInvents
author_rank: Contributor
timestamp: December 29, 2022, 06:54:51 am
content: Thank you for the clarification!
Replacing a moving coil (volt) meter with a digi display? - Page 1
Forum section: electronics / beginners

author: Chris Wilson
author_rank: Super Contributor
timestamp: April 28, 2014, 08:35:32 pm
content: I have restored a large linear PSU and found the panel volt meter, a taut wire suspended, moving coil movement of 1mA is kaput. I doubt I will find a direct replacement, as it's late seventies, early eighties vintage. It's nice unit, very stable, nice specification, beautifully made. I would have liked to have kept it original, but given this issue my mind is turning to a digital display on a nice machined panel to go in the space the 90mm X 75mm meter occupies. I have never given such a conversion much thought. Should I be thinking of ignoring the existing wiring to the meter, which is really measuring current, and wiring a digi display direct to the output terminals of the PSU? It's 0 to 60V output (at 50 Amps, so a big beastie). I suppose a digi display would flatter the potential stability and accuracy of the thing.... Just thinking aloud hereThanks

author: Rick Law
author_rank: Super Contributor
timestamp: April 29, 2014, 01:35:09 am
content: Suggestion 1: With such a huge opening (90x75mm), may be some of those 8x8 LED matrix in 4Ledx3Led arrangement? So 22.5mm x 25mm slot for each of those LED matrix. The top can display current, the bottom can display voltage, and with 4 high, you can also get a DS3231 and display the date/time + temperature.Suggestion 2: Better yet, get one of those LCD display and you can have a digital meter display as an analog meter like those dials in the airplane cockpit - and/or digital at the user's command.

author: Macbeth
author_rank: Super Contributor
timestamp: April 29, 2014, 02:59:09 am
content: You can get stacks of 2 wire or 3 wire triple digit floating point 7 segment displays in red (cheapest), green, yellow, blue for not more than a £1 each. I just bought a mix for less than beer or chippy meal money because I know I will find a use for them (and if I don't I can make a DeLorean time machine panel out of them). They have a trimmer for adjustment to a calibrated source if need be.It's a no brainer really. Unless it's audio equipment and then you need bumping backlit analogue needles and bargraphs and stuff.

author: Joule Thief
author_rank: Regular Contributor
timestamp: April 29, 2014, 04:29:38 am
content: Please read the spec sheet for any potential candidate for your supply. Some panel meters may require the addition of a small DC to DC isolated supply module for the panel meter electronics.
Replacing AA power source with 18650s - Page 1
Forum section: electronics / beginners

author: jasonvincenzo
author_rank: Newbie
timestamp: July 30, 2017, 05:29:03 am
content: A while back i made a pretty killer portable speaker out of a case, small amp, 2 decent speakers. Currently i have had it running off of 8 AA batteries to get the 12v dc that the amp takes. Right now it doesnt last very long and it does not like to get very loud. (i have tested with with 2 very nice shelf speakers and it got very loud when using the power supply) So i was wondering, i have a few old laptops and i use the 18650 cells in my camping flashlight and lantern. Would it be possible to use a few to power the amp? Sorry, new to this sort of thing.The power supply that came with the amp outputs 12v and 3 amps.Any more information needed and i can get it for you.EDIT:18650s and Samsung branded ICR18650-22F cells.Just using normal AA Duracell coppertops.

author: Zero999
author_rank: Super Contributor
timestamp: July 30, 2017, 08:20:14 am
content: Quote from: jasonvincenzo on July 30, 2017, 05:29:03 amHave you tried connecting a large capacitor, 10 000µF, in parallel with the 8 AA cells? The voltage might be dropping when the audio power reaches its peak. Adding capacitors will reduce the AC impedance of the supply, allowing it to provide high current spikes.Have you measured the voltage of the power supply the amplifier came with? It might actually be more than 12V, which would mean you need more than 8 AA cells.The AA cells probably still have lots of charge left in them when the amplifier. Try measuring the voltage when the amplifier stops working or sounds distorted.Yes, you can replace the AA cells with lithium ion but the problem is charging them and ensuring they don't discharge too much, which can cause them to fail which makes any attempts at recharging them dangerous.

author: amyk
author_rank: Super Contributor
timestamp: July 30, 2017, 02:50:54 pm
content: With 18650s you'll need to put the cells in series and use one of the various cell-protection ICs to stop any individual one from being overcharged/discharged. If you don't mind taking the cells out and charging them individually, then the circuit becomes much simpler.
Replacing broken iPod dock connectors - Page 1
Forum section: electronics / beginners

author: Skippy
author_rank: Contributor
timestamp: October 20, 2012, 06:13:09 pm
content: I was after some advice on how to desolder iPod dock connectors from PCBs.Here's what they look like:As you can see, hopefully, they've got two bits- a through hole bit round the outside which hold the connector in place, and some .5mm pitch SMD which are the contacts to the pins. Currently, I'm trying to use hot air, but I have to really blast it to get it all to melt at once, and I always seem to lift tracks on the board as you can see if you look at the board photo.If you wanted to get the connector off and not damage the board in, what would you do?

author: peter.mitchell
author_rank: Super Contributor
timestamp: October 20, 2012, 06:34:03 pm
content: Do you want to keep the connector? or doesn't matter?I'd just dremel the connector off then de-solder like normal.

author: Skippy
author_rank: Contributor
timestamp: October 20, 2012, 07:41:41 pm
content: The connectors are broken- that's why I'm removing them, so I don't want to keep them.

author: G7PSK
author_rank: Super Contributor
timestamp: October 20, 2012, 08:28:03 pm
content: Completely de-solder the through hole retainers using the iron and solder sucker/wick and then use the hot air to remove the rest of the unit.
Replacing caps in ATX PSU, Low ESR or not? - Page 1
Forum section: electronics / beginners

author: darko31
author_rank: Regular Contributor
timestamp: March 02, 2014, 12:26:23 pm
content: Hi everyone,I'm trying to fix a PSU which has couple of bulged caps. There are three bulged 10V 2200uF caps and one 16V 3300uF. Since my local electronics store doesn't have low ESR 16V 3300uF caps, is it okay to replace that cap with non low ESR one?I can't recognize whether the original one was low ESR, there are not any extra markings, and the PSU is low power, Macron MPT-251 , 250W, 13A on 12V rail, so i suppose it could be regular one.The picture of the cap is in attachment, on the other side it says 0203M which I assume is datecode.

author: Rasz
author_rank: Super Contributor
timestamp: March 02, 2014, 12:31:55 pm
content: lowesr, buy over internet

author: mariush
author_rank: Super Contributor
timestamp: March 02, 2014, 12:38:25 pm
content: No, it's not OK to replace with regular capacitors. The power supply needs Low ESR capacitors, but don't buy very low esr capacitors like the ones on motherboards (Nichicon HN, HZ, Rubycon MBZ etc), the capacitors on this power supply don't have such low esr to begin with and using such very low esr could cause higher ripple, oscillations etc.I would look at Nichicon HW, Nippon Chemi Con KZE , maybe Panasonic FM (but these start to be in the very low esr category), Rubycon ZL* ...If you have paypal and a few dollars , I can mail you some suitable ones from my own personal "stock"... better than buying some fakes from eBay.

author: darko31
author_rank: Regular Contributor
timestamp: March 02, 2014, 12:49:57 pm
content: Thank you, but it's too expensive to replace those caps with Rubycon, Nichicon, Panasonic or other high quality brands since the PSU itself isn't worth much. It looks like the original caps were regular ones, found some info in this thread, post #32.http://www.badcaps.net/forum/showthread.php?t=20722&page=2It's probably the reason why the PSU failed, although the dimensions look non standard, 120mmx86mmx150mm so it's pretty crammed in there and pissant 80mm fan not getting enough airflow. Otherwise it actually has pretty good build quality.
Replacing EL inverter, but not sure which pin is which (help tracing pcb?) - Page 1
Forum section: electronics / beginners

author: Mp3
author_rank: Frequent Contributor
timestamp: April 28, 2018, 01:40:11 am
content: Hi everyone, i am replacing an inverter on a power supply board, it was used to provide high voltage for an EL backlight, i have replaced that old screen with one that does not need the inverter so it has been removed.I wanted to replace the inverter with a resistor (the value is correct, i'm sure, i asked here) but now i am realizing i don't know which pin is which. Do i need the schematic to tell or can i measure the resistance between the 3 pins? (Pin "out" to the one above it registers 0.9 k Ohms, pin "out" to the pin diagonal from it registers 6 M ohms)The schematic shows "in", "out" and "com', but does not indicate which pin is which. I indicated the "out" pin but i am not sure which is "in" or "com". It looks like this:
Replacing Hot Air Station - advice ? - Page 1
Forum section: electronics / beginners

author: LeWidget
author_rank: Regular Contributor
timestamp: June 19, 2017, 05:31:00 am
content: Hi guys,I have a WEP 862D+ rework station and the hot air gun borked itself. I ordered a heating element but it didn't appear to be compatible, so I ordered the proper one locally. The heating element works, but the fan seems to no longer function. It appears, there's only around 2v on the fan positive line, which wont change even adjusting the fan speed. Still only a newbie, not sure how long before I can fix it, so Im just going to get a 2nd unit, and if I managed to repair the WEP, then keep it as a spare.With these two units, does anyone know if there's much difference between the hot air gun besides one having LCD digital display?http://www.ebay.com.au/itm/SOLDERING-IRON-HOT-AIR-GUN-REWORK-STATION-SOLDER-4-TIPS-3-NOZZLES-LED-YIHUA-878-/362006755993?hash=item544948ba99:g:dzUAAOSw~XpZP0ELhttp://www.ebay.com.au/itm/HOT-AIR-GUN-Desoldering-Soldering-REWORK-SMD-STATION-3-Nozzles-FOR-Yihua-858D-/261803709239?hash=item3cf4b79337:g:4qoAAOSwe-FU-rLLI'm leaning towards the YIHUA 878 as it's only $5 more and it comes with a soldering iron, which would come in handy as a spare, or use a 2nd different tip (saves waiting for one to cool down, then swapping tips)If it is just a digital display difference, that doesn't bother me. I'm sure (but could be wrong) having manual knobs might be a little easier to diagnose faults/issues, compared to digital display units ??Thoughts ?
Replacing Li-poly with Li-ion cells - Page 1
Forum section: electronics / beginners

author: olewales
author_rank: Regular Contributor
timestamp: February 01, 2016, 09:58:05 pm
content: Hello,I am trying to resurrect a power bank in which one of four li-po cells died. I don't want to throw it away because it has a handy feature of being able to provide 19V@2A and I plan to use it for powering TS-100 portable soldering iron. The problem is that replacing Li-po cells is going to be quite expensive. However there seems to be enough space inside to fit 4 18650 cells which are abundant on the market. Can they be used as a direct replacement? I've read that Li-po differ from Li-ions mainly in shape and their chemistry is very similar. Original cells had model number "ft853465p" on them (found a match inthisdocument). Cells are connected in series and there are taps between each of them so they are probably balance-charged. There is also a thermal sensor in the device.I'd appreciate any advice on this.

author: Chalcogenide
author_rank: Regular Contributor
timestamp: February 01, 2016, 10:27:07 pm
content: I think you will be fine. Just use 4 identical 18650 cells at the same state of charge (fully charged is the easiest to achieve) so that you start off with a well balanced pack. Also use cells rated for >3A discharge, but this should be easy.

author: DivineChaos
author_rank: Regular Contributor
timestamp: February 03, 2016, 12:03:11 am
content: Panasonic IMR 18650 and CGH 18650's are an excellent choice
Replacing missing diode on power supply - Page 1
Forum section: electronics / beginners

author: ronen1n
author_rank: Newbie
timestamp: July 04, 2022, 10:49:57 pm
content: HiI have canon mx495 that its power supply didn't work (k30363) and my friend tried to fix it unsuccessfully so i bought new one from chinaNow I'm trying to fix the old one and i see missing diode that called sr215. do i need to remove it to see its value?this is the old ps you can see the diode missing on up rightthis is the front diode up leftand this is the new ps
replacing mosfets in power amps - Page 1
Forum section: electronics / beginners

author: Simon
author_rank: Unknown
timestamp: January 28, 2010, 07:54:16 pm
content: I'm trying to find alternatives to the IRFP 240 and KTC 4370A power mosfets, now from what I can tell they are nothing special and they go into a power amp. I know that the IRF9540 and IRF540 are much the same but for voltage and higher voltage versions are available. How are mosfets selected for power amps ?

author: Zero999
author_rank: Super Contributor
timestamp: January 28, 2010, 10:25:44 pm
content: I assume you're talking about a class AB amplfier, not a class D amplifier.To be honest I've never designed a power MOSFET amplifier before but I suspect it's it's the same except being linear is more important and R-on is less important.

author: qno
author_rank: Frequent Contributor
timestamp: February 07, 2010, 11:27:04 am
content: One very important parameter is the Cgd.If the gate drive circuit is incorrect your amp is prone to oscillations.These oscillations will blow out your tweeter in no time.After replacement check the output with a scope on a load resistor (not a speaker) on zero to max power outputand look for oscillations on the signal. Yes, sweep the entire amplitude range.These oscillations are difficult to prevent. This is why Mosfets are not so popular in class A or A-B audio amps.
Replacing NC7SZ126P5X with 74HC245D - Page 1
Forum section: electronics / beginners

author: emir
author_rank: Newbie
timestamp: April 21, 2023, 10:02:11 pm
content: Hello,I am working with a pmod i2s module from Digilent and according to their schematic they have a non-inverting buffer for SDOUT from ADC feeding into the MCU ADIN_SDOUT.And I have been looking into its datasheetIn comparison to 74HC245DI have implemented it this way in my schematic:The logic table says this would be a correct way to pass data from A0 to B0.Digilent SCH:https://digilent.com/reference/_media/reference/pmod/pmodi2s2/pmodi2s2_sch.pdfNC7SZ126P5X Datashet:https://nl.mouser.com/datasheet/2/308/1/NC7SZ126_D-2316643.pdf74HC245D Datasheet:https://datasheet.lcsc.com/lcsc/1811131630_Nexperia-74HC245D-653_C5625.pdfEdit:Looks like I forgot to ask my question when it was late writing this post.I was wondering if my thinking is right and they would function the same way in this regard?

author: Benta
author_rank: Super Contributor
timestamp: April 21, 2023, 10:07:08 pm
content: And the question is?

author: emir
author_rank: Newbie
timestamp: April 22, 2023, 07:51:51 am
content: Quote from: Benta on April 21, 2023, 10:07:08 pmLooks like I forgot that when it was that late. My excuses.I was wondering if my thinking is right and they would function the same way in this regard?
Replacing Philips SonicCare HX939V battery - Page 1
Forum section: electronics / beginners

author: tlex
author_rank: Newbie
timestamp: May 15, 2023, 01:52:11 pm
content: I was able to follow the instructions on how to disassemble the toothbrush and I see that the battery is soldered on.I'm not able to find that exact same model anywhere so I was wondering if someone here faced the same problem and if so, what replacement did you used ?The place is tight and the battery legs are solid metal plates.Any advice appreciated

author: barshatriplee
author_rank: Regular Contributor
timestamp: May 15, 2023, 02:20:23 pm
content: I do not think, finding exactly the same brand is essential. You can replace the battery with something like this one:https://www.amazon.com/Electric-Toothbrush-Replacement-Battery-Compatible/dp/B08XVRZQV2

author: tlex
author_rank: Newbie
timestamp: May 15, 2023, 02:22:52 pm
content: That is also what I've found but if you check, it is unavailable everywhere...

author: tlex
author_rank: Newbie
timestamp: May 15, 2023, 02:25:39 pm
content: Oh sorry... it does ship to the US... not Canada, my bad.

author: barshatriplee
author_rank: Regular Contributor
timestamp: May 15, 2023, 05:40:56 pm
content: I think you can mail to this website and ask if these batteries are compatible with the HX939V model :https://bbmbattery.ca/products/philips-flexcare-toothbrush-battery-for-hx6920-hx6950-hx6930-and-moreIf possible, you can go to their shop and see.
Replacing protected cell with unprotected cell? - Page 1
Forum section: electronics / beginners

author: Brad808
author_rank: Contributor
timestamp: August 13, 2022, 02:33:50 pm
content: Hey everyone. I have a small portable speaker (doss ego II) that I've had for a few years and I'm thinking of upgrading the battery on it to have more capacity and have it longer lasting. The battery that is in there now is a single 18650 2200 mAh (which measures at 1744 mAh). I'm wanting to replace it with two 20700 3000 mAh batteries in parallel. I wired it up and it is working and physicaly fits into the speaker which is awesome, but I haven't tried charging or discharging it yet. The 18650 cell I took out is a protected cell and the 20700 pack I put into it is using unprotected cells. Is this a problem for this application? As far as I know (which is very little admitadly) the speaker is going to be handling all the charging and discharging with a low batter indicator and the cell protection is essentially a safety to prevent the cell from excessive current draw/ short circuits, etc? I was also reading that a BMS is only really required when running cells in series and not parallel?Thanks for any insight.

author: wraper
author_rank: Unknown
timestamp: August 13, 2022, 02:40:30 pm
content: It's a safety hazard. If anything goes wrong with charging circuit or device gets shorted there will be orders of magnitude higher chance batteries may explode in flames as circuit preventing it is no longer there. Not to say after soldering these cells they can no longer be considered safe as they can receive a lot of damage while doing so.

author: tunk
author_rank: Super Contributor
timestamp: August 13, 2022, 02:43:08 pm
content: I wouldn't do it, the speaker could rely on the BMS for both overcharging and over-discharge.

author: Brad808
author_rank: Contributor
timestamp: August 13, 2022, 02:48:24 pm
content: Quote from: wraper on August 13, 2022, 02:40:30 pmThere has been no soldering on the cells they are on spot welded tabs to run in parallel (soldered onto tabs and then spot welded to cell). Can the protection circuit be taken off the 18650 cell and run inline with the new pack?

author: mikerj
author_rank: Super Contributor
timestamp: August 13, 2022, 04:16:49 pm
content: Charge and discharge currents won't change by adding more capacity so you should be able to re-use the original protection board. Either way you should include protection.

author: Brad808
author_rank: Contributor
timestamp: August 13, 2022, 10:21:47 pm
content: Quote from: mikerj on August 13, 2022, 04:16:49 pmThanks I went ahead and installed it with the new batteries 🙂
replacing the 10V regualtor with a 12V one in this circuit? - Page 1
Forum section: electronics / beginners

author: dentaku
author_rank: Frequent Contributor
timestamp: August 09, 2015, 03:04:10 pm
content: I've been looking at the power supply for an old parallel port flatbed scanner I took apart a while ago.I'm wondering if I could easily modify it so that the -10V outputs -12V.It uses a 16VDC 900mA power brick (class 2 transformer, 120V 60Hz 20W) that measures about 20V which then gets used to produce +5V +12V and -10V.The 20V is stepped down to a bit over +7V using a LM3578AM Switching Regulator, through an inductor then straight into a KA7805 TO-220 regulator to generate the +5V. The +12V is just a KA7812 with a heatsink.QUESTION:The -10V is created using a KA7810 regulator THEN into an Alpha_AS7660S_DC-DC_Voltage_Converter to create a -10V output.http://www.ic72.com/pdf_file/a/40771.pdfCould I simply replace the KA7810 with a 7812 and get -12V out of the AS7660S?It's supposed to be good for up to 12V. I'm not sure how much current this thing can handle but I figure it's worth trying just for fun.

author: SeanB
author_rank: Super Contributor
timestamp: August 09, 2015, 03:52:02 pm
content: It is specced for 20mA, and a simple test is to just connect it to the 12V supply rail, no extra regulator required. Output resistance is 100R typically.

author: dentaku
author_rank: Frequent Contributor
timestamp: August 09, 2015, 04:01:27 pm
content: Quote from: SeanB on August 09, 2015, 03:52:02 pmDoh! Why didn't I think of that?I'm assuming it's still better to give the AS7660S it's own regulator even if it's just another 7812?It's also less messy.As for the current. I just checked again and now I see where that information is in the datasheet, hidden under Output Source Resistance.

author: SeanB
author_rank: Super Contributor
timestamp: August 09, 2015, 04:05:09 pm
content: Wouldn't even bother, the draw from the 12V regulator will be 50mA at most into a short circuit. Noise would be low as it is a CMOS switch, so slow edges in any case. Just use a low value inductor to feed it the existing 12V supply if you are worried, pretty much any value will so something.

author: dentaku
author_rank: Frequent Contributor
timestamp: August 09, 2015, 04:18:13 pm
content: Quote from: SeanB on August 09, 2015, 04:05:09 pmOK, I can just unsolder the 7810 and connect a wire from the output of the KA7812 to where the output of the 7810 used to be.

author: dentaku
author_rank: Frequent Contributor
timestamp: August 09, 2015, 06:18:08 pm
content: Well, it seems to work.I first just replaced the 7810 with a 7812 and I got -11.94V then I removed it and just connected the output of the KA7812 that's already on the board using a bit of small stranded wire to where the 7810 output used to be and I get -11.95V.I guess that's close enough for whatever I'm going to use this for. Considering it's just an experiment I don't know what I'd use a measly 20mA -12V supply for right now.
Replacing the connector in the UTG932E generator  - Page 1
Forum section: electronics / beginners

author: AlexRG
author_rank: Regular Contributor
timestamp: June 19, 2025, 12:14:03 pm
content: Hello everyone. It hasn't been a year since I bought this chinese generator, and it started having problems with the connectors. i turn on the meander, it is there. However, the meander arbitrarily breaks into a sine. If you move the connector cable, the meander returns again. But not for long. I tried to crimp the connector a little with pliers, but this does not last long. I tried to buy new cables, because I thought that the problem was in them, but the problem is not in them. The problem is in the low-quality chinese connectors. Either the mass or the central conductor is constantly lost. I am already tired of this and several chips have already burned out because of this.In general, please recommend a company and a model ofhigh-qualityconnectors.

author: electr_peter
author_rank: Unknown
timestamp: June 19, 2025, 01:02:36 pm
content: Quote from: electr_peter on September 04, 2022, 08:50:22 pmCheck links above, suitable connector is Amphenol 031-5486. You can also do 60MHz mod.

author: AlexRG
author_rank: Regular Contributor
timestamp: June 19, 2025, 03:34:00 pm
content: Quote from: electr_peter on June 19, 2025, 01:02:36 pmThaks!

author: CosteC
author_rank: Regular Contributor
timestamp: June 20, 2025, 06:35:30 am
content: Check also your cables. I got some Chinese BNC cables with connectors literally falling apart, made out of some zinc alloy with bubbles inside. Mechanical tolerance was also horrible causing bad contact.

author: AlexRG
author_rank: Regular Contributor
timestamp: June 27, 2025, 05:56:54 pm
content: Quote from: electr_peter on June 19, 2025, 01:02:36 pmUnfortunately, I won't be able to buy these connectors. But I have these in stock: TE Connectivity 5227161-7https://lcsc.com/product-detail/Coaxial-Connectors-RF_TE-Connectivity-5227161-7_C591726.htmlWhat do you think about this company, are these connectors quality or not?
Replacing the HP/Agilent 6060B DC load fan - inductance surge - Page 1
Forum section: electronics / beginners

author: hellzakk
author_rank: Contributor
timestamp: January 13, 2019, 04:45:01 pm
content: Hi all, i recently acquire a 6060B that need a new fan.The original one is a PAPST TYP 612 who operate in the range of 6-15 V-DC.The service manual (pag. 28) define this voltage levels for the fanQuoteSo i've chosen the TRACO POWER TEN5-1212Quoteto use with a Noctua NF-A6x25 FLXQuotehave a bit less airflow than the PAPST but is much more quiet and i dont use high power dissipation.My doubt is about the surge generated by the inductive load (fan) when i power off the unit, it can be dangerous for the DC/DC converter?Someone can explain how to calculate this behavior?Thank you.

author: AnalogSteph
author_rank: Newbie
timestamp: January 14, 2019, 02:06:57 pm
content: If you just need a new fan... why do you want to replace the fan driver as well?Here's some data for the Papst 612 fan, courtesy of an early-2000s catalog (that series was marked at obsolete even then):Throughput 40 m³/hStatic pressure 75-80 Pa (~ 8 mm H2O) @ 0 m³/h5300/min2.5 W40 dB(A) - 5.1 belsThey still make the replacement 600N series, the closest model would probably be the 612NN (42 m³/h, ~65 Pa, 5100/min, 1.6 W, 35 dB(A) / 5.2 bels). Your Noctua would be more along the lines of a 612NML (25 m³/h, ~25 Pa, 3000/min, 0.8 W, 19 dB(A) / 3.9 bels).I wouldn't just install a weaker fan. If you want to tweak something, the entire cooling concept should be examined, which in (vintage) test instruments can be rather crude (but might be somewhat more refined in a device that is pretty much design to dissipate power).At the very least, can the fan be shock-mounted (preferably without introducing air leaks in the process)? That used to help a lot with low-RPM Papst fans in the day, which have relatively few motor poles. Nothing more annoying than having this ticking amplified by the entire case. The designers of Siemens PBXs still haven't gotten the memo.Would there be ways of maybe fitting a second one in parallel, so a lower RPM model can be used?Is there sufficient intake area? With axial fans, obstructions on the output side tend to hinder airflow far less than a constricted input. (Oddly enough, the hot trend in 2018 PC cases was almost closed-off front panels with mere millimeters of clearance for front intake fans.)Now as for the question of indutive surge... anything wrong with the classic parallel diode trick?

author: hellzakk
author_rank: Contributor
timestamp: January 15, 2019, 01:02:48 pm
content: The old fan operate in the range of 6-15 V-DC and i dont know (no detailed datasheet available) if the noctua can work in the range reported (and measured) in the 6060B service manual.I thought to use the noctua for the low noise and as it reported working with a stable 12V input so the need of replace the supply driver... but your points are all right and i will go with a new PAPST 612NN.About your last question i think the flayback diode is ok, but id like to know how to calculate the surge spike generated by a 12v fan.
Replacing trim pot with multi turn on buck regulator - Page 1
Forum section: electronics / beginners

author: Stuartambient
author_rank: Regular Contributor
timestamp: November 15, 2016, 02:34:50 pm
content: I bought a relatively inexpensive 10 turn pot for a buck regulator (pic attached). Made the mistake of not seeing the power rating of 2W on the 10 turn when I ordered it. I'm wondering if the power produced though would actually be running through the pot? Currently I run the regulator up to around 3Watts. Seems to work fine and I don't imagine (i could be wrong) that the trim pot has much of a power rating either. I do expect to generate more power with some other applications, ~6-7W.If the circuit though has all the power going through the pot maybe I should look for something with a higher rating? I know the picture doesn't show the actual circuit but maybe it helps.TIA

author: Ysjoelfir
author_rank: Frequent Contributor
timestamp: November 15, 2016, 03:19:52 pm
content: You are totally fine with your 10 turn 2W pot, those tiny trim pots used on the original design are useable for up to a few mW, i would guess 250mW max.The power will go in no way through the pot, they are only used with signal levels. So - keep it the way you do right now, there shouldn`t be any problem at all.

author: Stuartambient
author_rank: Regular Contributor
timestamp: November 15, 2016, 06:00:39 pm
content: Excellent, thank you!