hybridfree/eevblog-posts huggingface dataset:
Power supply for audio service - Page 1
Forum section: electronics / general

author: Raziel92
author_rank: Contributor
timestamp: March 31, 2023, 04:15:41 pm
content: Hello, im looking for power supply suggestion, it will work in audio service, powering power stages from amplifiers thats why i need min 45V2 channel that can work in series (symetrical power supply)Min 45-60V,1-2A will be enoughBoth channels must be switched on/off with 1 keyClearly UILinear prefeerBudget about 1000 euro

author: jonpaul
author_rank: Super Contributor
timestamp: March 31, 2023, 05:12:50 pm
content: DIY? Make one or many? HiFi...high end? consumer? Home theatre?j

author: Wallace Gasiewicz
author_rank: Super Contributor
timestamp: March 31, 2023, 05:38:59 pm
content: Are you looking for a PS that can power tube audio?There are some OLD ones including BK and Heathkit that come to mind.Some have power for filaments, Bias and then Plate volt.I have a nice one at the shop for sale unfortunately I am in USA.Wally

author: Raziel92
author_rank: Contributor
timestamp: March 31, 2023, 05:39:39 pm
content: Consumer hi-fi, hi-end, mostly from the years 80'-00' only transistor amplifiersGwInstek GPP-6030 seems to have everything what I needAlready have bench multimeters and lcr meter from them for few yearsBut its little above budgetAnother type i found is Korad KC6403, looks nice in building quality, a bit messy UI but nowhere i have found info if it can work in series mode or only with 4 independent channels

author: MathWizard
author_rank: Super Contributor
timestamp: April 03, 2023, 01:45:14 am
content: Yeah if used equipment is okay, I'd check the local classified ads. I'm on the look out for old stereo reciever's, to use their giant heatsink's and transformers. To order them new, would cost a lot, at least this way I'll get a bunch or reusable extra's, like caps, diodes, power transistors, etc.
What do people weigh their iron stands down with? - Page 1
Forum section: electronics / general

author: killingtime
author_rank: Regular Contributor
timestamp: March 30, 2023, 08:04:59 pm
content: Hi,I've got an Antex bakelite iron stand. Not expensive, but it works, and I like the large sponge. The problem with it being plastic is that it's light and I always end up pushing it round the bench. Sometimes the weight of the cable seems like it could tip the stand over. So what do people weigh their stands down with? I've tried wood but it's not heavy enough. Don't want to glue \ screw it to the desk as it needs to be portable. I could 3d print a box and fill with sand I suppose. Just interested to see what others have done.Thanks.

author: srb1954
author_rank: Super Contributor
timestamp: March 30, 2023, 09:19:28 pm
content: If it has any internal cavities fill them with cement. Otherwise fabricate a bracket to hold a roll of solder on the back - that should provide plenty of weight.

author: coppice
author_rank: Super Contributor
timestamp: March 30, 2023, 09:24:23 pm
content: If you want a good iron stand you need an iron one, like thishttps://en.goot.jp/products/detail/st_11Cheap, simple, in production for decades, and I've never seen one tip over.

author: thm_w
author_rank: Super Contributor
timestamp: March 30, 2023, 09:27:01 pm
content: Photo would help.Gluing large steel washers inside the bottom may be an option.Quote from: coppice on March 30, 2023, 09:24:23 pmNeeds more brass wool.

author: jwet
author_rank: Frequent Contributor
timestamp: March 31, 2023, 04:25:02 am
content: I use a square of hot rolled steel, just a 4x4" x 1/4" scrap. I sanded it on a belt sander to knock the knife edges and rust off. I use some magnetic widgets with it- Amazon stuff, one is a iron stand. I have a thinner steel plate that came with the mag widgets. The thicker steel really attracts magnets. I have several irons that I keep on a shelf below my bench (you can see in pic attached somewhat) and have this holder on my bench for the job at hand- a pics attached.

author: killingtime
author_rank: Regular Contributor
timestamp: March 31, 2023, 11:10:20 am
content: The steel plate looks like a good idea. I'll need to visit a scrap yard.Thanks for the replies.
Aifen A9 - is it safe?  - Page 1
Forum section: electronics / general

author: dinth
author_rank: Contributor
timestamp: April 21, 2022, 08:28:50 pm
content: Hi. Following up on my previous thread herehttps://www.eevblog.com/forum/reviews/clone-t12-hotair-is-it-safe-(photos-included)/where you helped me greatly, i would just like to ask about a second station i received today.Sorry for the poor quality photos - this station looks better built, so i dont want to disassemble it into pieces without a good suspicion. Are there any checks i should do on it?

author: tcurdt
author_rank: Contributor
timestamp: August 05, 2022, 09:39:43 pm
content: It's really weird there so little to find about this station.

author: sobakava
author_rank: Contributor
timestamp: November 09, 2022, 08:03:56 am
content: Quote from: dinth on April 21, 2022, 08:28:50 pmDo you measure any voltage between between the tip and ground / earth?

author: thm_w
author_rank: Super Contributor
timestamp: March 29, 2023, 11:41:28 pm
content: Tip is NOT earth grounded.You can see the yellow/green lead going off to the circuit board. On the circuit board there is a capacitor from earth to the supply 24V ground, that is it.I measured 9V AC with no noticeable current (<1mA) between the tip and ground. So it shouldn't immediately blow anything up, but I would still prefer an earthed tip for safety.Shorted out that capacitor and its still working OK (temperature is stable, sleep still works). The cradle is pulled up to ~5Vdc using a wire inside to main PCB.One minor annoying thing about this station is no spots for tips, but seller included a nice stainless container for them.Also tip removal metal is not tied to the cradle, so removing the tip does not turn off the heater.. could add a small jumper wire for this if you change tips often.Peak power when turning on: 140WMax power when soldering:- knife tip 40W- conical tip 20WPerformance is good but as expected you might not hit high power when soldering due to the limitations of a thermocouple based iron. But you'd see a lot higher with a proper short chisel tip, the knife tip is a bit long.Other thread:https://www.eevblog.com/forum/reviews/any-sugonaifen-a9-c210c245c115-users/
VPC300 particle counter - Page 1
Forum section: electronics / general

author: joniengr081
author_rank: Regular Contributor
timestamp: March 23, 2023, 01:24:46 pm
content: I am wondering what is the unit of particle counts in VPC300. Are these numbers (counts per particle size) are measured in per cubic meter ?

author: thm_w
author_rank: Super Contributor
timestamp: March 23, 2023, 10:05:32 pm
content: ug/m3is the standard measurement unit yes.But it looks like it depends on what mode you are in:"Particle Count Modes Cumulative, Differential, and Concentration modes"https://www.fondriest.com/pdf/extech_vpc300_manual.pdf

author: joniengr081
author_rank: Regular Contributor
timestamp: March 24, 2023, 06:59:05 am
content: ug/m3 look like a unit of density but the measurements should be in terms of count per m3 or count per cm3, maybe ft3. I am not getting how it related to density.

author: joniengr081
author_rank: Regular Contributor
timestamp: March 24, 2023, 08:46:09 am
content: The user manual says "If a room is classified as an ISO clean room or clean zone, the counts of particle sizes for thatclass cannot be exceeded when tested. Refer to the ISO Clean Room Class chart (ISO 14644-1:1999) for values." I have looked at the maximum particle count limit for ISO 5 to ISO 8 and found that these numbers are per m3. But the unit in which VPC 300 is displaying is not clear to me.

author: thm_w
author_rank: Super Contributor
timestamp: March 24, 2023, 09:19:17 pm
content: Quote from: joniengr081 on March 24, 2023, 06:59:05 amIf you have it set to cumulative, then its just counting the total number of particles. Does anything change if you set it to concentration mode?But seems you are right, its counts per m3. Then if needed use some equations to convert it to ughttps://www.researchgate.net/post/How_to_convert_mass_concentrations_ug_m3_to_particle_number_concentrations_particles_cm3

author: joniengr081
author_rank: Regular Contributor
timestamp: March 27, 2023, 09:11:56 am
content: I understand the cumulative mode and differential mode but don't understand the concentration mode. How it differs then the other two modes ?If it shows the numbers in the unit of per m3 than it's fine but it is not clearly written in the user manual. Where can I see the measurement unit documented ?
My KSGER T12 is slow (vs. 936 clone) - Page 1
Forum section: electronics / general

author: bogdan2014
author_rank: Regular Contributor
timestamp: February 10, 2023, 07:27:22 am
content: I have a KSGER T12 v2 station with a bunch of KSGER tips and a 936 clone with cheap chinese tips. Comparing the two, I noticed that the 936 is much faster, given the same temperature (350C) and similar tip size. I sometimes struggle to solder larger parts with the KSGER even with something like a DL32 tip, whereas with the 936 it's a breeze (again, with the temperature set at 350C).I don't see any drops in temperature or voltage (the PSU is 24V/5A).I see people praising T12 stations so I'm starting to think either the tips are crap or I'm missing something else. By the way, I also tried different handles and it's the same.

author: ygi
author_rank: Regular Contributor
timestamp: February 10, 2023, 12:00:55 pm
content: What do you mean by "slow"? Does it take like 3min to get to temperature? If so then there's probably an issue with the mosfet on the controller board.Otherwise what you described looks like a matter of thermal mass. Even if two tips are shaped the same way, the one that's heavier or bulkier usually stores more heat and can deal with bigger instantaneous heat loss from coming in contact with a big component or large ground. Also, counterfeit T12 tips from China tend to not be as well made than the original Hakko's (less copper, thin plating, poor bonding with heating element). Even with 1KW power supply and controller, if the tip isn't physically capable of delivering the heat into the board, you might as well just be working with a 20W iron.So, at the end of the day, cost cutting and crude manufacturing can fail to make decent T12 cartridges much easier than it can fail to make plain 936 tips. If there's a T12 type you really like and use often, you should buy that one genuine from Hakko.

author: AWAIS91119
author_rank: Contributor
timestamp: March 26, 2023, 03:20:00 pm
content: Check the actual tip temperature of both irons. Maybe the KSGER is not calibrated and actual temp is roaming around 250*C
What mains harmonic class is hair removal product? - Page 1
Forum section: electronics / general

author: Faringdon
author_rank: Super Contributor
timestamp: March 23, 2023, 10:07:52 am
content: Hi,What mains harmonics class is the "smoothskin bare" supposed to be compliant to?Smoothskin bare:https://www.currentbody.com/products/smoothskin-bare-ipl-hair-removal-device-black-and-rose-gold?variant=40655221227564Is it Class B, because it is essentially a "portable tool"?, or is it class A, ie, "everything else"?Obviously its not Class C (lighting), and not class D (Monitors, TVs, and compauters)

author: tggzzz
author_rank: Super Contributor
timestamp: March 23, 2023, 10:15:32 am
content: Quote from: Faringdon on March 23, 2023, 10:07:52 amA typical Faringdon/treez topic starter: enough content to get people responding, but not insufficient content for people to give useful responses.I suggest people refrain from responding until Faringdon/treez has read and understood and acted upon the points in thesecond paragraph. That's the one about "Don’t ask “Can you give me a lift into town?” Do ask...".
Slowing Down A 115V Electric Motor (capacitor start induction type) - Page 1
Forum section: electronics / general

author: John-O
author_rank: Contributor
timestamp: March 20, 2023, 07:46:21 pm
content: How do I slow down this 115V electric concrete mixer? It runs at a constant 25rpm. We need to do prolonged mixes, but at slower rotation speeds. Is there an off the shelf plug-in controller I can use for this purpose, or will it be a bit more complicated than that?All inputs and suggestions will be highly appreciated.PS: My apologies for the flipped pictures, they are rotated correctly but somehow flip when uploading.

author: John-O
author_rank: Contributor
timestamp: March 20, 2023, 08:02:13 pm
content: The motor is apparently a capacitor start, induction type motor (rating 110uf) - as per the manufacturer.

author: Xena E
author_rank: Frequent Contributor
timestamp: March 20, 2023, 08:42:04 pm
content: Trying to slow down that type of motor with an inverter won't work well.To be positive, you could try:Changing the motor to a three phase unit, then if necessary control through an inverter.Modifying the drive or gearing. Some of those machines use belt drive from the motor to gearbox, it looks like they may be so. You could investigate different pulley ratios.A big reduction could be done by driving the gearbox from a geared motor. That could have a proportionally lower power than the current motor as the torque would be increased by the gearing.Xena.

author: John-O
author_rank: Contributor
timestamp: March 20, 2023, 09:02:06 pm
content: We need to change the speed as required, back and forth, so a permanent fix/change will not do unfortunately.

author: Xena E
author_rank: Frequent Contributor
timestamp: March 20, 2023, 09:10:11 pm
content: Then you need a motor that will support speed control: the present one will burn out its start winding and capacitor if you reduce the speed below the pullout of the centrifugal switch.

author: John-O
author_rank: Contributor
timestamp: March 20, 2023, 09:11:21 pm
content: I just got feedback from Dart Controlswww.dartcontrols.com/and they said capacitor start type motors are made to run at one speed and nobody makes such controllers.

author: John-O
author_rank: Contributor
timestamp: March 20, 2023, 09:11:57 pm
content: Quote from: Xena E on March 20, 2023, 09:10:11 pmYes, it seems that way.Thank you.

author: Xena E
author_rank: Frequent Contributor
timestamp: March 20, 2023, 09:22:00 pm
content: The only way to speed control those motors is by nature a kludge, and you have to be careful not to stall them, it involves variable frequency inverter drive and disconnecting the start circuit after it is up and running, Its not a job for a newbie, (no offence), and as I said carries a risk of the motor being damaged if it stalls.No drive manufacturers will back such a system with a guarantee.Hope you find a solution.Regards Xena.

author: John-O
author_rank: Contributor
timestamp: March 20, 2023, 09:35:46 pm
content: Thanks Xena. Yes, I need a simple plug-and-play system, which is not available for this problem. So, I need to find another mixer.
KSGER T12 Recommendations - Page 1
Forum section: electronics / general

author: neoOberon
author_rank: Newbie
timestamp: March 05, 2023, 07:49:13 pm
content: Hi,...Stereotypical long time listener, first time caller introduction.I want to buy my first soldering station - Currently I use a Weller WP35 for the odd soldering job I do. It's been fine for what I use it for, but I'd like to learn/practice PCB soldering.I was going to buy what's generally considered the default upgrade (I think) - a Weller WE1010NA or a Hakko FX888. But after diving deeper into the murky depths, it seems a Chinese knockoff cartridge system is better than the aforementioned.I've settled on theKSGER T12 V3.1S, but I'd welcome input based on my inexperience.1)On the KSGER Official Store, the 3.15S stations have the following disclaimer -Note: We have changed the soldering station chip to MM32 from 2021/12/1. But it will be same firmware and same function with STM32,so please donot worry about it.- Does anyone know how theMM32chip compares to theSTM32?-ShouldI worry about it?2)Is there a consensus on which KSGER T12 is best?- The standard all in one unit or the mini that requires a 24volt power supply?- Other than grounding and the dodgy capacitor, does it just come down to personal preference?3)Can anyone give me recommendations on a handle - way too many choices for a newb like me.4)Follow up; Can I get recommendations on what tips to choose? Stick with the 3 that come with it?KSGER Official Storehttps://www.aliexpress.com/store/1486111?spm=a2g0o.store_pc_groupList.pcShopHead_6041349.0STM32um er ah, theMM32 V3.1S Stationshttps://www.aliexpress.com/store/group/STM32-V3-1S-Station/1486111_516916735.html?spm=a2g0o.store_pc_promotion.pcShopHead_6041349.1_0_2

author: tatel
author_rank: Frequent Contributor
timestamp: March 06, 2023, 04:42:38 am
content: https://www.eevblog.com/forum/reviews/soldering-station-purchase-advice/msg4612993/#msg4612993

author: neoOberon
author_rank: Newbie
timestamp: March 06, 2023, 03:13:17 pm
content: Thanks for the link to your thorough run down of the T12.After reading David's GitHub, looks like the V2 is the one to get - you did make a convincing argument to use his firmware.Thanks again

author: tatel
author_rank: Frequent Contributor
timestamp: March 07, 2023, 11:02:58 am
content: https://aliexpress.com/item/1005003064223657.htmlIt seems there is an special offer right now. Please make sure it has an original STM32 or CKS clone. Quicko is said to have better quality than Ksger. The blue handle is said to be best one. I have 9051 and happy with it. Complete stations are probably better than frontend + external power supply wrt ESD. Check protective earth. Look at the pictures: if screen to board connection is 6 pins, then it uses SPI, faster than I2C (four pins) But I2C is fast enough anywayThey change models and processors so often that it is difficult to give an up-to-date advice. Check the custom firmware thread. Best wishes

author: mastershake
author_rank: Frequent Contributor
timestamp: March 20, 2023, 10:21:41 am
content: v3 works perfectly fine as long as you get an stm32 version or a decent clone.
Anyone bought an ultrasonic cleaner recently? - Page 1
Forum section: electronics / general

author: apelly
author_rank: Unknown
timestamp: January 12, 2023, 07:13:34 am
content: Wondering if anyone has bought an ultrasonic cleaner recently and may have some supplier recommendations.I bought one some years ago now, and although it hasn't seen a lot of use it shat itself today. Not sure if I should buy new driver boards of not. Looking at the transducers, it appears that two of them have been hot enough to melt the solder on their power wires. I think they might be jiggered too.The more experienced among you might be able to spot the subtle issue with this driver board:

author: kermitfrog
author_rank: Contributor
timestamp: March 19, 2023, 05:20:46 am
content: Bought one off Ebay that goes under the name "DK Sonic" Has a warranty. Had a minor issue with it and they stood behind it. Sent me another new unit.

author: MK
author_rank: Regular Contributor
timestamp: March 19, 2023, 12:41:27 pm
content: that capacitor between the two power devices is not in the best of health

author: apelly
author_rank: Unknown
timestamp: March 19, 2023, 07:33:11 pm
content: Quote from: MK on March 19, 2023, 12:41:27 pmLooks like it wanted some air cooling

author: apelly
author_rank: Unknown
timestamp: March 19, 2023, 07:37:59 pm
content: Quote from: kermitfrog on March 19, 2023, 05:20:46 amJust took a look. Found the DK Sonic brand, but which seller did you use that backed up their sale? Do you remember?
Workzone Digital Calipers at Australian Aldi stores? - Page 1
Forum section: electronics / general

author: sausage
author_rank: Regular Contributor
timestamp: March 17, 2023, 04:38:40 am
content: Aldi currently have Workzone calipers for sale. $20 isn't too bad, but reviews are pretty mixed for the ones they've brought in the past. Anyone bought one of these this month and have any thoughts?Based on Dave's comments on the recent amp hour about cheaper calipers being all pretty decent with their capacitance reading, it might be an OK buy.Still I'm happy to shell out a few more dollars for something solid... but would be good to be a middle of the road price.

author: BurningTantalum
author_rank: Frequent Contributor
timestamp: March 18, 2023, 10:23:02 am
content: The main issue with all of these cheap calipers is the short battery life. I have a couple but never use them because it seemed that every time I got one out of the cupboard I had to ferret about for a new button cell. I have been tempted to bodge on a tiny slide switch to isolate the battery.BT

author: wilfred
author_rank: Super Contributor
timestamp: March 18, 2023, 11:13:41 am
content: I'll second the comments regarding short battery life. They work fine otherwise. I take the battery out which is a pain but I don't use it frequently enough to think about a better solution. A solar cell like a calculator would be good. If there is one on the market that solves the battery life issue get that one.

author: sausage
author_rank: Regular Contributor
timestamp: March 18, 2023, 11:37:48 am
content: Thanks to you both. I had a assumed that there would have been an on/off switch and that the calipers don't run when not in use. Clearly I'm wrong.

author: tooki
author_rank: Super Contributor
timestamp: March 18, 2023, 01:22:30 pm
content: I have one of these bought years ago (so no guarantee it’s the exact same innards as today’s). Not worth the money, because it sometimes misses counts and ends up displaying a number that is off by some multiple of 5.08mm.These things chew through batteries because the “power” button just turns off the LCD, which barely uses any power anyway… The entire measurement circuitry is apparently still on. I have no idea how Mitutoyo and others with true auto power on do it, but the cheapies don’t do it properly.They also don’t slide as smoothly as quality ones like Mitutoyo, Mahr, Tesa, or Sylvac. Not a deal breaker as such, but just not as nice to use.I then got a vernier Mitutoyo on sale for something like $35 which works great, and eventually I’ll get around to buying some quality digital calipers. Those also come in various useful options, like different lengths, shape of the depth gauge pin (square for disability, round to fit in smaller holes), with or without the thumbwheel, bigger displays, IP rating (so dust or water ingress doesn’t mess up measurements), data ports or bluetooth, etc.
Permanant marker for IC - Page 1
Forum section: electronics / general

author: Buck
author_rank: Newbie
timestamp: March 16, 2023, 11:07:49 am
content: I am looking for a marker for IC in different colors. The use case is to indicate if an IC have been reworked with lead solder or if it is broken.The requirement is that it needs to be permanent and can withstand IPA and flux. I also the paint needs to handle heat of 400 degrees C.I did try the Edding 750 markers but they fly off once you apply some flus and blow with the heat gun.Any suggestions for a product that can fulfill my task?

author: jpanhalt
author_rank: Super Contributor
timestamp: March 16, 2023, 11:51:31 am
content: There are a few solutions I have used. Mechanics use markers in disassembly to ensure correct orientation when reassembling. Wax pencils and various "magic" markers will work. Of course black is not very evident, but silver is also available. I use the silver version occasionally.*What I prefer is a paint marker, and specifically the fine lineDecoColor brand by MARVY UCHIDAin the USA. They are made in Japan, and the brand name may be different for you. I have tried other, less expensive brands, and the tips seem to dry out quickly. I can leave a DecoColor marker for months, even a year or more capped, and it is still usable. Of course, it has the usual warning label as it contains xylene.*Edit: Sharpie brand

author: RoGeorge
author_rank: Super Contributor
timestamp: March 16, 2023, 12:08:53 pm
content: Make specific scratch-marks on them, with any sharp pointed tool around.

author: Buck
author_rank: Newbie
timestamp: March 17, 2023, 09:47:11 am
content: Thanks "jpanhalt" for the tip. I just orderd a Marvy decocolor pen to testAnye more marker tips?Also scratching the IC is actually a good idea but unfortunately it is not possible in my situation. I need a color that is really clear and the marking can not be mistaken for a "scratch" from the factory or anything similar.

author: amyk
author_rank: Super Contributor
timestamp: March 17, 2023, 10:32:29 pm
content: Quote from: Buck on March 17, 2023, 09:47:11 amEngrave something distinctive.
TL866 and Cypress FM16W08 FRAM - Page 1
Forum section: electronics / general

author: cheeseit
author_rank: Regular Contributor
timestamp: January 03, 2017, 06:39:32 pm
content: I had apparently the mistaken impression that the TL866 was capable of programming a FM16W08 if DS1225 was selected as the device. I can't get it to work and have tried more or less everything available in the UI. The FM16W08 works as a replacement for DS1225 in at least some gear.The GQ-4X4 programmer does work with it and guess that I must have overlooked that and just assumed people were using the popular TL866.There does not seem to be any pattern to this but when reading it all bytes holds the same value but the value often varies when doing consecutive reads. It usually starts of with 0x00. Programming it sometimes apparently succeeds but does not program it for real. Filling it with 0xFF sometimes work with verification enabled, and works realiably if then doing it again, but if I then try to write real data it fails.I've read and programmed other devices so the programmer works fine. I also know that a difference is that the FM16W08 needs to have CE strobed for each access, and that is not the case for DS1225, and I believe this is the reason why it's not working.Cypress datasheethere.Is there any way to get this to work?

author: branadic
author_rank: Super Contributor
timestamp: May 21, 2023, 08:05:09 pm
content: For FM16W08 you would have to select DS1220 (24pin) and for FM18W08 you would have to select DS1225, DS1230 or DS1235 (28 pin).See also:https://www.arlabs.com/device.html-branadic-
Desk Shelf - Page 1
Forum section: electronics / general

author: Lowkus
author_rank: Regular Contributor
timestamp: March 18, 2023, 04:21:46 am
content: Is there a good place to get a shelf unit that can sit on top of my desk so I can put stuff on the desktop while also storing stuff above the desk? The desk is against a window so the shelf has to be supported entirely by the legs that sit on the desk. I could probably make one with three planks of wood but I'd rather get something more polished.stuff <-- Shelf where stuff sits----------| | <--- Shelf thing, sitting on desk| || |---------------||| ||| <--- Desk (about 140cm wide and 60cm deep)||| |||||| |||

author: rdl
author_rank: Super Contributor
timestamp: March 18, 2023, 12:46:27 pm
content: I used something like this for a while.https://www.amazon.com/Whitmor-Stackable-2-Shelf-Storage-Organizer/dp/B07227Q695/The one I had was Closetmaid brand from Home Depot and it was about half the cost.

author: Bud
author_rank: Super Contributor
timestamp: March 18, 2023, 03:24:48 pm
content: MDF will sag if you put anything heavy on it. Try IKEA for shelfing made from solid wood or engineered wood.

author: kripton2035
author_rank: Super Contributor
timestamp: March 18, 2023, 04:57:49 pm
content: MDF will not sag if you reinforce it with perpendicular smaller boards screwed and/or glued, at the back of the shelf.I made one with 23mm pine, the shelf is 150cm wide. shelf is loaded with scopes and power supplies, no saging for years.

author: rdl
author_rank: Super Contributor
timestamp: March 18, 2023, 07:16:33 pm
content: You can also use small aluminum angle stock which can also double as a glare blocker/reflector for LED rope/strip lighting. A 36" piece is about $10 at Home Depot.

author: Shock
author_rank: Super Contributor
timestamp: March 19, 2023, 02:56:46 pm
content: Rectangular bookcase or cut any bookcase or shelving to size at your local timber place.Just ensure it has or add lateral support to avoid collapsing sideways if you are using heavy equipment, screws aren't enough if it's cheaply constructed. If it's tall prevent it from tipping by anchoring to the desk.Here are a couple of ideas, using seamless wall shelving with legs or pipes for legs.

author: Electro Fan
author_rank: Super Contributor
timestamp: March 19, 2023, 07:29:53 pm
content: Quote from: Lowkus on March 18, 2023, 04:21:46 amAmazon is worth a look see

author: tggzzz
author_rank: Super Contributor
timestamp: March 19, 2023, 08:32:43 pm
content: Quote from: Bud on March 18, 2023, 03:24:48 pmSolid wood + Ikea? Reference please.Particle board, fibre board, cardboard honeycomb, yes.
Medical Alert Pendant Teardown - Page 1
Forum section: electronics / general

author: jonovid
author_rank: Super Contributor
timestamp: March 08, 2023, 03:36:02 am
content: its 4G phone electronics and SIM with out a screen or keypad.only two buttons on the case.one Lithium-ion 800 mAh 96Wh batterymic & speaker also mini vibration motor or shaker.plus 7goldpogo pins.the products two yr life expectancy had expired.

author: Krotow
author_rank: Regular Contributor
timestamp: March 10, 2023, 06:42:11 pm
content: Charge the battery in LiPo/Li-Ion battery charger and it will work again. If battery is dead, you can replace it to similar Lipo battery with protection circuit. Like thishttps://www.aliexpress.com/item/32996924752.html

author: jpanhalt
author_rank: Super Contributor
timestamp: March 10, 2023, 07:39:30 pm
content: I had a "free" one offered by my Medicare intermediary (age 80). My thinking was that the idea sounded good for someone living alone in a rural area. After 2 weeks, I turned it off and tried to return it. The Medicare intermediary wasn't interested. It was disassembled, then put in the trash.Problems:1) False alarms. My contact person (daughter) ws worried to death. She survived.2) Rural community, trees, and medi-alert do not work well together. Most of the time there was not 2-way communication, hence the false alarms.Solution:I send an email when I start some dangerous thing outside, then cancel the alert to my contact person when I am done.

author: jonovid
author_rank: Super Contributor
timestamp: March 12, 2023, 04:43:00 pm
content: the product has a two yr life expectancy then its replaced. even if it working ok. so it become e-waste. I do notwasteElectronics, I post images on eevblog then re-use the 96Wh battery for other projects. dismantle any or all of it. google part numbers , look for any re-use I can get from it .the gold =$
Microscope mounting posts - Page 1
Forum section: electronics / general

author: daveismissing
author_rank: Contributor
timestamp: February 14, 2023, 06:00:41 pm
content: Are the posts for the typical microscope stand all(mostly) the same diameter?, Does anyone know what that diameter might be. Speaking of the usual Ali/Bang good/whatever products.D

author: ygi
author_rank: Regular Contributor
timestamp: February 14, 2023, 08:19:35 pm
content: AFAIK, diameter is either 25 or 32mm. I'd say 25mm is more common when it comes to Chinese imports. Though, the 25mm head uses a plastic reducer to turn the 32mm hole into a 25mm that you could pop out. Look at the picture, you'll get what I mean:

author: daveismissing
author_rank: Contributor
timestamp: February 15, 2023, 06:27:58 pm
content: Thank you so much!

author: daveismissing
author_rank: Contributor
timestamp: March 08, 2023, 08:53:16 pm
content: And now for the real surprise - when this one (Wally Sky) arrived the hole was 14mm

author: jfiresto
author_rank: Frequent Contributor
timestamp: March 08, 2023, 09:50:32 pm
content: So what size shaft might it need?I am having some fun satisfying a microscope that expects a 24½mm shaft.

author: ygi
author_rank: Regular Contributor
timestamp: March 09, 2023, 02:48:16 pm
content: Quote from: daveismissing on March 08, 2023, 08:53:16 pmWelp, that unusual when it comes to binocular microscopes. Even my lightweight USB microscope stand uses a thicker shaft.Quote from: jfiresto on March 08, 2023, 09:50:32 pmThat's what the diameter of my "25mm" shaft really is when measured with a caliper.

author: jfiresto
author_rank: Frequent Contributor
timestamp: March 09, 2023, 05:20:07 pm
content: Quote from: ygi on March 09, 2023, 02:48:16 pmI would think that would feel a little loose. Mine measured 25±0·05mm.

author: ygi
author_rank: Regular Contributor
timestamp: March 09, 2023, 09:00:44 pm
content: Well, there's a brass ring insert inside the head mount hole that gets squeezed against the shaft as a part of the locking mechanism. That ring fits snugly into a groove in the shaft allowing the head to rotate without sliding down when the locking screw's loosened.That's this black part to the right:
Ohm test single phase motor opinion or fact - Page 1
Forum section: electronics / general

author: WiredSmart
author_rank: Contributor
timestamp: March 07, 2023, 02:01:04 pm
content: I watched a video whereby someone was testing a single phase motor and chose the first highest reading as the START windingAfter googling other articles to help me better explain how to carry out the test i found conflicting results whereby; the highest reading of the windings were between run and start therefore making the start winding the second highest ohm reading .https://www.electricalengineeringtoolbox.com/2015/12/how-to-test-and-check-single-phase.htmlWhat are the correct readings to focuse on finding the run , start and common winding

author: armandine2
author_rank: Frequent Contributor
timestamp: March 13, 2023, 07:52:12 am
content: https://www.amazon.co.uk/Electric-Machines-Gordon-R-Slemon/dp/0201077302Looking through Slemon this weekend, I see the phase split is accomplished with an auxiliary winding with a higher resistance to reactance ratio than the main winding.It seems, thin wire can be used for the higher resistance only if the auxiliary winding is switched out of circuit after the motor has started.
Adam Audio T5V active studio monitors (nearfield) - Page 1
Forum section: electronics / general

author: aeberbach
author_rank: Regular Contributor
timestamp: March 06, 2023, 09:47:42 pm
content: Source is Windows or Mac through a Focusrite USB interface going to the powered monitors via balanced cable, music via Apple Lossless or my own MP3s, 256K VBR. I can't tell the difference between that and CDs anyway.Started with Presonus Eris 3.5 monitors and they were OK. Not great, just OK. They did not really have the bass or the treble but they are compact and for the price, very happy... they will probably become luxury retro computer speakers.Bought Presonus R65 mkII speakers and they were a huge improvement, especially good on the treble BUT unusable on the computer desktop due to loud hiss and pickup of computer interference. When not listening to music you are listening to the mouse moving around or the CPU doing its thing. On opening them up I found they reuse Presonus boards from older products and of course caps nobody has ever heard of.Read some reviews and decided to roll the dice again on Adam Audio T5V - wow! They actually are as good as everyone says. I am still going through all my favorite music and hearing it again. And when not playing music they are inaudible as they should be. I can detect a slight hiss if I put my ear right up to them but nothing to disturb quiet time. Maybe the only bad thing about them is that they have no detent on the gain knob? There's a 10" sub available for around the same price as the pair but I don't think I need it.(and the Focusrite interface has started to make a bit of a scratchy noise when adjusting the monitor output. I need to open it and look at the pot but they are tough to get into)
JBC Chinese parts - Page 1
Forum section: electronics / general

author: Johnny10
author_rank: Frequent Contributor
timestamp: March 03, 2023, 09:08:46 pm
content: JBC C-245 Handle China OEM part.I noticed on eBay there are sellers with JBC OEM. C245 soldering station handles. Has anyone tried these?

author: thm_w
author_rank: Super Contributor
timestamp: March 03, 2023, 09:51:23 pm
content: Link?SDG has many videos including them:https://www.eevblog.com/forum/other-blog-specific/the-sdg-electronics-soldering-station-comparisonshootout-thread/Probably some variation depending on the brand, but I haven't heard any major complaints.

author: DavidAlfa
author_rank: Super Contributor
timestamp: March 03, 2023, 09:55:50 pm
content: It depends.Cloned handles (These with the green rubber grip) aren't made for the power, contacts will overheat and melt the plastic, while the Chinese C245 cartridges have the worst soldering performance and lifespan I've ever seen.Jabe stations are ok, we have them at work, but using genuine cartridges.
Desoldering station chisel tip thoughts  - Page 1
Forum section: electronics / general

author: Fallenrecruit
author_rank: Newbie
timestamp: February 27, 2023, 08:46:51 am
content: Had the idea / Slight need for a chisel shaped desoldering iron tip and would like to get some thoughts on whether or not it would actually be functional, I have roughed up what I was thinking it would look likeThis is for a YiHUA 948I I thought I might add.

author: Fallenrecruit
author_rank: Newbie
timestamp: February 27, 2023, 09:01:05 am
content: Just another thought that came to my head was to bevel the tip to make it get into the root a bit better

author: thm_w
author_rank: Super Contributor
timestamp: February 27, 2023, 11:12:19 pm
content: I can't really see this working for anything through hole, if you tilt the tip you'll lose full contact with the PCB which means little or no suction.Can you describe where you'd use this tip? SMD parts?I like that you are thinking of an alternative though.

author: tooki
author_rank: Super Contributor
timestamp: February 27, 2023, 11:22:55 pm
content: Pace makes something sorta like this, the 1121-0934, which is for desoldering things like the mounting legs of DC barrel jacks, potentiometers and rotary encoders.But remember that you need room for airflow, so you can’t make the hole too tiny.

author: Fallenrecruit
author_rank: Newbie
timestamp: February 28, 2023, 08:24:08 am
content: QuoteWas thinking of using if for desoldering things with largish tabsQuoteI did a quick area calculation and the inlet side is about the same size as the outlet side, not entirely sure if it will work at all but its worth a shot, I have the lathe and mill to be able to prototype it so I'll see how I go when I get some material

author: tooki
author_rank: Super Contributor
timestamp: February 28, 2023, 05:53:15 pm
content: I’ve used the Pace equivalent, and it’s a useful, if somewhat specific, tool. Remember to not make the tip too thin; you need the mass to transfer heat to the tabs — tabs which are substantially larger than typical component leads, and which connect to a much larger mass of metal on the other side of the board. The hole also can’t be too narrow, since the tabs are often bent and thus need extra width.

author: tooki
author_rank: Super Contributor
timestamp: February 28, 2023, 06:00:55 pm
content: I’d also suggest watching Pace’s video on desoldering technique:https://youtu.be/IqE1KA0OAnMat 17:55.It’s part of a video users manual for a very old model, but the technique is absolutely unchanged.That should give you an idea of what you want in a desoldering tip.
4G LTE Cat 4 vs Cat 1 - minimum guaranteed upload speed? - Page 1
Forum section: electronics / general

author: Martin F
author_rank: Regular Contributor
timestamp: February 24, 2023, 08:52:09 am
content: Hi all,We are looking to evaluate two alternative 4G LTE modules, one with 4G LTE Cat 1 and one with 4G LTE Cat 4.As part of this, we can easily identify what the maximum upload speeds are for each type (5 Mbps vs. 50 Mbps).However, we are trying to understand what the 'minimum guaranteed upload speeds' are for both. We've heard that for LTE Cat 1 it's 1 Mbps and for LTE Cat 4 it's 5 Mbps, but we can't find any formal sources of this information.Does anyone know what the numbers are - and where a source can be found?

author: Emo
author_rank: Regular Contributor
timestamp: February 24, 2023, 09:11:13 am
content: Hi Martin,Mobile connections don't have a minimum connection speed. It all depends on the quality of the radio link(s). The maximum however can be obtained and is depending on bandwidth, 3GPP release and mode. The mentioned LTE CAT1(probably LTE-M cat1) does indeed have a maximum of 1.05Mbit/s in the uplink under R14.Available open sources;https://www.sharetechnote.com/html/Handbook_LTE_Cell_Selection_Criterion.htmland of course the 3GPP body with all the standardisation documents

author: Martin F
author_rank: Regular Contributor
timestamp: February 24, 2023, 09:37:04 am
content: Hi again,To clarify, it is not LTE-M Cat 1, but regular 4G LTE Cat 1.In our in-house tests we did experience that our LTE Cat 1 module would fluctuate between 5 Mbps upload speed (max speed) in some frequency bands, while it would fall to 1 Mbps on other frequency bands. It never falls below 1 Mbps, hence indicating that there may be a capped minimum speed.For this reason, we wanted to understand if there were some official standards stating this for LTE Cat 1 and Cat 4 respectively, in order to determine if it would make sense for us to perform similar tests on a Cat 4 module to determine if the 'minimum capped upload speed' appears to be 5 Mbps for this module.
Atten ST-862D Vs Quick TR1300A Side By Side Video & TR1300A Teardown Post - Page 1
Forum section: electronics / general

author: KG7AMV
author_rank: Frequent Contributor
timestamp: September 08, 2021, 04:31:11 am
content: Size ComparisonI also Did a Quick Video.And aMini Teardown Of The Quick TR1300A

author: KG7AMV
author_rank: Frequent Contributor
timestamp: October 21, 2021, 01:05:27 am
content: Link Fixed.A Look Inside The TR1300A

author: Serpent10i
author_rank: Newbie
timestamp: October 27, 2021, 09:39:28 pm
content: Hey, I just got an Atten ST-862D and also did a quick tear-down of my unit. Highlights are attached here, the full teardown is in the imgur album here:https://imgur.com/a/wzcvhUb

author: KG7AMV
author_rank: Frequent Contributor
timestamp: November 02, 2021, 10:08:26 pm
content: I have not torn down the Atten yet.. Soon I will..

author: KG7AMV
author_rank: Frequent Contributor
timestamp: January 28, 2022, 07:55:32 am
content: I have put this Quick TR1300A to good use the last few months been a nice machine no regrets.

author: KG7AMV
author_rank: Frequent Contributor
timestamp: February 08, 2023, 01:20:35 pm
content: It has been over a year not one issue with the TR1300A Very happy.
What's inside this LED panel, how easy to modify? - Page 1
Forum section: electronics / general

author: mcovington
author_rank: Regular Contributor
timestamp: February 07, 2023, 01:32:36 am
content: Has anybody here ever reverse-engineered an LED tracing panel like this one?https://www.amazon.com/dp/B07D57F8X7/I use it in front of my astronomical telescope to take flat frames (photographs that record the uneveness of the light distribution, including spots of dust, so it can be corrected). I'd like to make it a little easier to use: have it light up only at its minimum brightness setting, with an on-off switch (or whenever power is applied), without variable brightness or any other functions. I gather it is not pulse-width modulated, so basically we're dealing with a power supply. Can anyone tell me more? (I'm quite conversant with electronics, just too lazy to open it up myself before asking whether others have.) Thanks!

author: Krotow
author_rank: Regular Contributor
timestamp: February 07, 2023, 09:52:14 pm
content: Pretty much look like the new incarnation of the good old photo negative viewer. Or base of microfilm viewer. That Amazon frame have matte mirror film at bottom, perpendicularly mounted white LED-s around frame inside rim and matte glass above all. LED driver and switch are hidden inside frame too. Rougly likein this frame(not mine).
What is this? - Page 1
Forum section: electronics / general

author: Connecteur
author_rank: Frequent Contributor
timestamp: February 03, 2023, 10:26:29 pm
content: Well, obviously, it's a flashlight, but I couldn't find a thing about it on the internet. It doesn't seem to open in any way, and there's a switch with two positions; "on" and "recharge." I experimented with charging by connecting my power supply to the two metal terminals. It took 1-2 mA at 4V, but a red charging light didn't come on until it reached 7V, so I assume it contains two lithium cells. I've had it charging for 2 days now, but it won't take more than about 7 mA. The red charging LED illuminates, so I assume I have the polarity correct. No sign of overheating, but I assume the cells have been dead for so long that they don't take much of a charge. I have brought back other cells. It looks like some sort of small light that clips into a charger. Diamar seems to be a ski equipment manufacturer, but there's no mention of flashlights on their website.

author: Andy Watson
author_rank: Super Contributor
timestamp: February 03, 2023, 10:34:54 pm
content: The chromed end looks as if it might fit into a car lighter socket - i.e. it might be 12V.

author: Connecteur
author_rank: Frequent Contributor
timestamp: February 03, 2023, 10:40:07 pm
content: Quote from: Andy Watson on February 03, 2023, 10:34:54 pmI never thought of that. Thanks.

author: Connecteur
author_rank: Frequent Contributor
timestamp: February 03, 2023, 10:41:25 pm
content: I actually attached 4 pictures, but it only shows 1.The preview feature doesn't work either. Kinda sucks.

author: thm_w
author_rank: Super Contributor
timestamp: February 03, 2023, 10:46:58 pm
content: Looks like Andy figured it out:https://www.pfyc.com/GN2027.html

author: Gyro
author_rank: Super Contributor
timestamp: February 03, 2023, 10:55:56 pm
content: https://youtu.be/4x0HQVRBm6w

author: Connecteur
author_rank: Frequent Contributor
timestamp: February 04, 2023, 05:37:02 am
content: Thanks for the help. I gave it the full 12V and it stayed around 7 mA, but the red charge light brightened right up.The lamp itself is also good and bright; maybe 50 lumens. I don't know how long it will run, but that's not too important for a light like this.I can see why it charges at a low rate, being always plugged into the 12V socket

author: pcprogrammer
author_rank: Super Contributor
timestamp: February 04, 2023, 05:46:01 am
content: Quote from: Connecteur on February 03, 2023, 10:41:25 pmThe attachment system is a bit broken. Instead of using the drag and drop or the first browse button you are better of using the "(more attachments)" option and the new browse button that gives for an attachment. Repeat the step for more attachments.
Oscilloscope Recommendation - Page 1
Forum section: electronics / general

author: AnarchistWolf
author_rank: Contributor
timestamp: February 01, 2023, 06:08:22 am
content: Hello, currently my lab is looking for an inexpensive (under $400) oscilloscope that has a large memory depth (above 70k).We make low cost instruments and finding a cheap oscilloscope for instrument replication in other groups labs would be great (Currently we use a Siglent 1204X-E, and we have seen the 1202X-E but want to see other options).We are looking for a scope that has a large memory depth and can be programmed/ scripted through Python. Bandwidth and sampling rate do not seem to be a concern with any scope ive seen for our application so ill exclude specs for that.Thank you for any recommendations.

author: thm_w
author_rank: Super Contributor
timestamp: February 01, 2023, 10:11:52 pm
content: https://www.eevblog.com/forum/testgear/