hybridfree/eevblog-posts huggingface dataset:
Unidentified componets - Page 1
Forum section: electronics / beginners

author: SG-1
author_rank: Regular Contributor
timestamp: June 01, 2011, 05:31:13 am
content: Can anybody help identify the two componets closest to the LED ? I first thought one was a zener, to regulate the output of the LED, but a test proved that incorrect. I now think it could be a Transient Voltage Suppressor ? Thanks for any help.

author: SG-1
author_rank: Regular Contributor
timestamp: June 01, 2011, 05:34:36 am
content: I suppose it would be helpful to mention the test. I applied 10,20, & 30VAC to the inputs & the voltage across the LED changed from 2.2, 2.7, & 2.9 VDC. The LED brightness changed appreciably with the voltage.

author: Mechatrommer
author_rank: Super Contributor
timestamp: June 01, 2011, 05:39:08 am
content: i think you got the label backward. the bottom part (yellow) is capacitor to stabilize the rectifier output and the top part with striplines is resistor to drain the caps, i dont like it, i just prefer it to be removed (waste of energy). though i'm not 100% sure since i cannot trace where the Vac going (under the rectifier)

author: A Hellene
author_rank: Frequent Contributor
timestamp: June 01, 2011, 05:58:34 am
content: The LEDs are current-driven devices --they are not voltage-driven ones.Anyway, the schematic of this device seems to be very simple:The four input resistors are 470Ω/0.5W each and they form an input bias resistor of 1K88/2W, which feeds the LED with a current of 8..21mA minus 1mA the small bleeding resistor (color coded: Red-red-green-brown: 2.25KΩ) draws.The components that are in parallel to the LED are:1. A rather beefy (for the size) capacitor of a value between 0.47 .. 2.2μF to make the LED light smoothly (and not flicker due to the AC drive), and2. A bleeding resistor of 2K25 to discharge the capacitor quickly when the power is removed, in order to prevent the LED from fading out.-George

author: SG-1
author_rank: Regular Contributor
timestamp: June 01, 2011, 06:51:54 am
content: Thank you, Mechatrommer & A Hellene, the fourth colour band was throwing me off on the bleeding resistor.
Unidentified DC connector - Page 1
Forum section: electronics / beginners

author: jay
author_rank: Regular Contributor
timestamp: December 31, 2013, 04:56:34 pm
content: I've spent hours googling and asked every electronics expert that I know. Actually I only know few so I'm sure someone here knows right away a name for this DC connector. It's used in some Chinese solar panels. Please see attached picture and let me know if you know what type it is. Or even better, where to get those.

author: bmwnomad
author_rank: Contributor
timestamp: December 31, 2013, 05:03:10 pm
content: SAE plug

author: Nerull
author_rank: Frequent Contributor
timestamp: December 31, 2013, 05:05:20 pm
content: It's an SAE connector. Automotive supply places might have them.http://en.wikipedia.org/wiki/DC_connector#SAE_connector

author: Jonny
author_rank: Regular Contributor
timestamp: January 01, 2014, 02:25:52 am
content: Narva have themhttp://www.narva.com.au/products/browse/weatherproof-harness-connectors.Automotive places here carry Narva, I saw some mentioned under marine use as well so try boat shops
Unidentified Device - Page 1
Forum section: electronics / beginners

author: allanfort486
author_rank: Unknown
timestamp: April 14, 2017, 05:13:30 pm
content: Hello EveryoneI have been trying to identify a device that I received when I bought some random parts on Ebay. It is a small device about 3mm x 3mm and has a mirror like surface but if you look through a magnifier at the right angle you can see some markings. I have been able to get this information from the device.1950-1AP 10303060_0569E TWNA search on Google did not seem to bring up any relevant information.The bottom of the device looks like a BGA and this is as much as know about it.Has anyone come across this device that can help me please.Please see attached photo

author: amyk
author_rank: Super Contributor
timestamp: April 15, 2017, 02:01:44 pm
content: It's a WLCSP, i.e. a bare die with balls on it.I think it'sthese.(Newer datasheethere.) At least the "AP" would make sense as a marking.

author: allanfort486
author_rank: Unknown
timestamp: April 15, 2017, 05:51:44 pm
content: Thank you so much amyk I was beginning to think I would never discover what these things were. At least now I can do a little research into these devices, Not that I will be clever enough to make use of them but you never know.
Unidirectional pulse to a transformer - Page 1
Forum section: electronics / beginners

author: ZeroResistance
author_rank: Frequent Contributor
timestamp: April 13, 2018, 11:49:13 am
content: To understand transformer action I have wound 2 windings on a ferrite flat and was pulsing one of the windings with a unidirectional pulse. And I am getting some some wierd voltage waveforms on the secondary. I just wanted to confirm whether these kind of voltage waveforms are expected on the secondary. I have checking voltage across the second winding in open circuit mode.Img1 is the currnent pulse measured thru a wire piece in series with the primary winding.Img2 is the voltage pulse measured across the open circuit secondary winding

author: ogden
author_rank: Super Contributor
timestamp: April 13, 2018, 11:57:07 am
content: Quote from: ZeroResistance on April 13, 2018, 11:49:13 amNothing unusual for open circuit transformer. "Ringing" is normal behavior. Try it in real world application circuit.

author: ZeroResistance
author_rank: Frequent Contributor
timestamp: April 13, 2018, 12:16:00 pm
content: Will putting an 100K load across the secondary help?

author: RoGeorge
author_rank: Super Contributor
timestamp: April 13, 2018, 12:34:52 pm
content: What do you mean by "unidirectional pulse"?

author: SG-1
author_rank: Regular Contributor
timestamp: April 13, 2018, 12:51:07 pm
content: I think he means only the positive half of the sine wave.This is similar to using the inductive kick method to determine the polarity of a transformers terminals. Except a battery is generally used for that, so the input is more of a square wave.

author: ogden
author_rank: Super Contributor
timestamp: April 13, 2018, 02:52:49 pm
content: Quote from: ZeroResistance on April 13, 2018, 12:16:00 pmDepends on transformer power rating and ratio. What voltage you expect to come out of transformer? What Power you expect to put into transformer? - Knowing output voltage and power, you can calculate resistor value which is needed to dissipate all the power you putting into transformer. Resistor as "test load" is only for testing and your learning. Usually you connect other than resistors, loads.
Unifi Switch 8-150W Blown R13 – Repair or Replace? - Page 1
Forum section: electronics / beginners

author: munnaz
author_rank: Newbie
timestamp: August 24, 2025, 09:43:56 am
content: Setup:Unifi Cloud Key+2x Unifi Switch 8-150WVarious PoE devices (cameras, UAPs, Bosch security)Issue:House breaker tripped, and one switch went offline.On inspection, R13 is visibly blown (photo attached).Questions:Is R13 a fuse, and is it worth replacing?How can I test the 8 PoE devices to rule out what may have caused it to blow?I’m considering switching to a Dream Machine — tired of Cloud Key+ HDDs dying every 6–8 months.New 8-150W switch is ~$150 AUD. Should I just replace the unit?Appreciate any advice. Cheers.

author: munnaz
author_rank: Newbie
timestamp: August 24, 2025, 09:56:07 am
content: I just also have seen this other blown component just from the mark on the pad. So I dont think the board is repairable, but any advice on the other questions would be great. Thanks.

author: Psi
author_rank: Super Contributor
timestamp: August 24, 2025, 10:07:03 am
content: Quote from: munnaz on August 24, 2025, 09:43:56 amFirst guess would be the caps were starting to die and no longer full capacitance so it couldn't handle the full load any more and blew up.So it may not have been anything you connected to it.If it was me I'd first be trying to power up the main board without the powersupply using a lab powersupply to confirm the powersupply didn't also take out the main board when it blew.Since if that happened then it's not worth fixing.With two parts already dead on the powersupply it's more likely other parts are dead too. Are you able to confirm which side of the circuit the blown parts are on, mains side or DC side.Its better if they're on the mains side, since dead parts on the DC side means unwanted voltages were on the DC side and probably got onto the bigger pcb too.

author: gadzmos
author_rank: Newbie
timestamp: August 28, 2025, 03:52:57 am
content: If you have a server where you can run VMs you can eliminate the cloud key by just spinning up a VM. If you don't have a server you can find old SFF PCs on eBay and use Proxmox as a hypervisor... then you can spin up lots of VMs for various self hosted servers (Unifi, PiHole for caching DNS and filtering, etc).With regards to the board, I agree with Psi... try powering it from a DC power supply and see if you can bypass that portion of the circuit to assess the full damage.
Unintentional capacitive coupling - Page 1
Forum section: electronics / beginners

author: renzoms
author_rank: Regular Contributor
timestamp: October 27, 2019, 11:50:47 pm
content: This question comes from text from the AOE 3rd ed. It's about unintentional capacitive coupling right after differentiators in chapter 1.I dont understand: “resistor termination on your signal line.” and “reduce the source resistance of the signal line.” I understand how capacitors, charge, voltage, and current, differentiators supplied DC, sin, and squarewaves so Figure 1.45 makes sense. I've written and attached a 7 page document about capacitors I'm currently working on. Would you please help me by rephrasing the parts of the text I don't understand, providing an example, and or explain like I'm five (elif). Thanks.https://docs.google.com/document/d/12gug-CDFmSIw96a-6j31GgybIcRjOr09F0q_aluErJ8/edit?usp=sharing
Uninterruptable Power Supply - Page 1
Forum section: electronics / beginners

author: rthorntn
author_rank: Frequent Contributor
timestamp: November 05, 2013, 01:51:49 am
content: Hi,May I just say what a bunch of extremely helpful people you areI got to thinking about home security and specifically thieves just switching your power off before they rob you because no doubt a lot of the more basic security systems out there don't have a battery backup, my fuse box is unlocked and on the outside of the house.I would like to keep the security system active for a period of time without spending a fortune on an expensive UPS.I have 4KW of solar panels with two strings feeding in to an Aurora inverter, it would be cool to somehow be charging a big battery with that to power the security system.Does anybody have any ideas or thoughts about the best way to do this, I could probably get to a situation where all of the security stuff was running off 12v?Thanks for looking.CheersRichard

author: alxnik
author_rank: Regular Contributor
timestamp: November 05, 2013, 07:52:52 am
content: 1st order of the day. Lock your fuse box.You can supply anything from 12v if the batteries are beefy enough, but if you security system runs off mains voltage then you will need an inverter so basically a UPS. Also, charging your batteries straight from the panels is tricky too, it depends on the max voltage of each panel and the way they are connected. You will need a specific voltage regulator - which exists in your inverter.

author: johansen
author_rank: Super Contributor
timestamp: November 05, 2013, 08:35:48 am
content: 4kw of solar implies you should have a 48 volt battery bank but i digress.fieldlines.com would be a better place to ask your question.there is a trade off between cost and reliability vs warranty.you can get a 20 year warranty on 98+% efficient hardware if you're willing to pay for it.

author: G7PSK
author_rank: Super Contributor
timestamp: November 05, 2013, 08:52:29 am
content: All security systems I have seen have a 12 volt back up battery in them, I have a friend who installs and services them, he always has a supply of cheap second hand SLA batteries removed from security systems that have been serviced as they are changed every 2 years as a matter of routine to ensure that there is no battery failure in the systems, so there must be a place in your system for a back up battery.

author: SeanB
author_rank: Super Contributor
timestamp: November 05, 2013, 06:16:34 pm
content: Never met a security system without a backup battery. Generally this also powers the siren as well, as then you can get by with only a 1A trickle charger, which cuts cost and standby power use a lot. If yours dies with the mains the battery is dead, deceased, probably bloated and most likely cracked and leaking acid over the case it is in. Replace with another and nothing else is needed. Even alarms from the early 1970's had a battery, and often those alarms had absolutely nothing electronic in them aside from the diodes in the battery charge circuit.
United Systems corp nixie instrument - Page 1
Forum section: electronics / beginners

author: Maurizio1957
author_rank: Contributor
timestamp: March 07, 2020, 02:03:50 pm
content: Hi everyone I'm looking for information on an old instrument that I had from a friend long ago, I can't find nothing from the web. It has 4 nixie tube and a neon lamp marked ERROR on the front panel. I'd rather have some information about it before plugging it in and seeing clouds of smoke....It has a label marked United Systems corp model 275ANS .Many thanks to all, Maurizio IU5BEC
Units for inductors on schematic - Page 1
Forum section: electronics / beginners

author: SethGI
author_rank: Regular Contributor
timestamp: August 07, 2017, 02:36:33 am
content: Hi,Just out of curiosity, what could the unit be on the 600 by the inductor on the image of the schematic I've attached. I know in general units are Henry's, but obviously they aren't calling for a 600 henry inductor. There's no other information available about the specific part. Any ideas? Am I missing something obvious?Thanks!-Seth

author: SethGI
author_rank: Regular Contributor
timestamp: August 07, 2017, 02:44:56 am
content: Awesome thanks! And congrats on that 1500th post!

author: mgraves235
author_rank: Newbie
timestamp: August 07, 2017, 09:46:10 am
content: millihenries?Alot of wah pedal inductors are in the 500 to 600 mh range.
Units of X/Y/Z - Page 1
Forum section: electronics / beginners

author: asg32000
author_rank: Contributor
timestamp: January 19, 2016, 03:03:07 am
content: I am working with a pressure sensor that has a "Sensitivity" rating with units of ?V/V/mmHg. I believe ?V is the output voltage, V is the excitation voltage (for the wheatstone bridge), and of course mmHg is the pressure you are sensing. My question is: when trying to calculate the expected ?V output, would I do something like this?(?V/V/mmHg sensitivity rating)/(excitation votage V * pressure in mmHg)You can't just do standard "order of operations" to calculate this, right? e.g. X divided by Y, then divide that by Z? X/(Y/Z)...?Any help would be appreciated.

author: rich
author_rank: Frequent Contributor
timestamp: January 19, 2016, 03:52:22 am
content: Vout = Sensitivity * Vexcite * pressureThink of as if you increase any of the 3 variables, you would expect the voltage to increase.Or use the units as a clue to get:Sensitivity = Vout / Vexcite / pressureand rearrange with algebra from there:Sensitivity = Vout / (Vexcite * pressure)Sensitivity * (Vexcite * pressure) = Vout

author: asg32000
author_rank: Contributor
timestamp: January 19, 2016, 01:44:37 pm
content: Thanks! That shouldn't have been so hard... Somehow I forgot to think about it algebraically. I appreciate it.
Universal LCD Control Board - Page 1
Forum section: electronics / beginners

author: Vadomaer
author_rank: Newbie
timestamp: November 30, 2024, 12:16:52 pm
content: Hello all,I have an MT561-B universal LVDS LCD control board. It requires a 5v power supply and I'm trying to use it with a 10.1-inch B101XTN01.1 LCD panel.https://www.amazon.ca/dp/B095N9CDGV?ref=ppx_yo2ov_dt_b_fed_asin_titlehttps://www.panelook.com/B101XTN01.1_AUO_10.1_LCM_overview_19966.htmlThe panel is 3.3V, and I have the 3.3V jumper selected on the control board. With a 5V power supply, the board powers up, and I can see a faint image displayed on the LCD, but the backlight isn't working. I think the backlight requires 12V, and I'm not sure how to supply the required voltage to it.Any help is appreciated.

author: tooki
author_rank: Super Contributor
timestamp: November 30, 2024, 01:05:38 pm
content: The red connector is the power input, right? Surely the backlight voltage goes into the pin labeled “BL”??

author: mariush
author_rank: Super Contributor
timestamp: November 30, 2024, 01:33:06 pm
content: Yeah, the red connector (CN4) is just a header to connect a backlight driver to the main board and bring 5v to the board from the power supply. Usually, the backlight driver is on the same power supply board that gives 5v to the display board.It has two grounds, two 5v pins, adjust brightness and enable (on/off or something like that)If the panel has a built in backlight driver on the panel board, it should have pins with ground, voltage, adjust, enable pins.If it's just wires connected directly to the led strips, you need a backlight driver board.See datasheet, from page 15 onwards :https://www.beyondinfinite.com/lcd/Library/Auo/B101XTN01.1.pdfIt says there backlight section needs minimum 6v, maximum 21v, and typical is 12v ... it also says that maximum backlight power is 1.8 wattsSo basically 18v x 0.1A = 1.8 watts , 12v x ~ 0.15-0.20 A is 1.8w ... 6v x 0.3 A is 1.8wPage 18 tells you the 40 pin connector pinout, here's the last pinsSo the last 3 pins on your 40 pin connector are voltage (at least 6v), LED_EN is the on/off , enable pin, most likely last pin on the red header, PWM goes to that ADJ pin on the red header.So I would use a 7.5v/9v/12v power supply and then use a small 5v linear regulator to give power to the board and therefore the lcd panel.
Universal voltage transformer but what about changing frequency  - Page 1
Forum section: electronics / beginners

author: Mp3
author_rank: Frequent Contributor
timestamp: March 24, 2021, 02:54:17 pm
content: I have attached a picture of a power supply I am working with. Suitable for worldwide voltage.I have one USA model 120v 60hzI have one Europe model 230v 50hzIt has a jumper with 5 pins on the AC filter board, this jumper determines whether incoming AC is 240v, 230v, 120v or 100v.So I change it from 230v to 120v. But I don’t see how to change frequencyI don’t see any visual difference besides the voltage jumper when comparing the two units...The unit that has been converted from 230v to 120v is running hot. The voltage from the power supply board is surely coming out a bit higher, about 10-20% higher voltage than the unit that was designed for 120v 60hz.The power supply goes to regulators which bring the voltage down to the appropriate level for the circuit, so the circuit is safe, but I want to know what I need to fix so that the unit is not running hot because it’s expecting 50hz and getting 60hz

author: CaptDon
author_rank: Super Contributor
timestamp: March 24, 2021, 03:10:53 pm
content: Getting 60hz instead of 50 would run cooler, not hotter. Older equipment from the states built for 60hz and not designed for European 50hz will often self destruct at 50hz. The reverse is not true. European 50hz equipment runs extremely well on 60hz.

author: Mp3
author_rank: Frequent Contributor
timestamp: March 24, 2021, 03:18:09 pm
content: Quote from: CaptDon on March 24, 2021, 03:10:53 pmAhhh gotcha. Thanks for that.So it's something else that is making that power supply run hot.There is no service manual available for these things so I think I will have to put them side by side and find out where the power starts running higher on the 50hz unit than the 60hz one.

author: Jwillis
author_rank: Super Contributor
timestamp: March 26, 2021, 03:59:06 am
content: I would recheck how the primary is configured for the transformer. Sounds like you may have one or more of the taps mixed up . For example if the primary is set up for 100V and put on 120V mains that would raise the secondary by 20% and because there is less impedance on the primary winding set at 100V it would run hotter at 120V.
University software - Page 1
Forum section: electronics / beginners

author: Landore
author_rank: Newbie
timestamp: October 23, 2021, 08:24:01 am
content: A little off-topic, but I needed the help of more experienced people urgently.The task is that I need to write a final paper for the university, which should consist of 40% of the literature, as well as a description of the programs that were used to implement the entire project.Consequently, my question is whether there is any forum that discusses the Autodesk software package as well as Photoshop and a few other graphics editors that have been used to implement some of the project details.Perhaps there is a service that could do this work for me? (In my texts a huge number of grammatical mistakes, which will also affect the final grade).I'm sure many of you have faced a similar problem, so I'm really counting on your help. I have no one else to turn to!Thank you in advance for your help, have a nice day!!!

author: Simon
author_rank: Unknown
timestamp: October 23, 2021, 12:49:00 pm
content: It's so nice for two spammers at once to give themselves away in one topic.
Unknown(to me) electronic elements - Page 1
Forum section: electronics / beginners

author: TNb
author_rank: Regular Contributor
timestamp: August 02, 2014, 09:58:55 pm
content: Hi! I recently salvaged some components from various stuff and found two strange elements, hope you will help me identify what is it.1) This is the thing from washing machine, I tried to google this stuff, but found only that this is a "filter", none of websites specifies what kind of filter this is, probably someone can understand it from schematics on the package.2) This is from old soviet speed regulator pedal of sewing machine. Quite thick cylinder with some graphite-like stuff inside. No marking at all. My guess is resistor, but who knows O_o

author: tautech
author_rank: Super Contributor
timestamp: August 02, 2014, 10:28:31 pm
content: QuoteIt is an X-Y mainsfiltercap for management of small spikes on the mains supply to protect the supplied circuit.GoogleX-Y mains filter capfor more info

author: Andy Watson
author_rank: Super Contributor
timestamp: August 02, 2014, 10:43:22 pm
content: QuoteAlso known as Delta Suppressor filters.Was the carbon resistor thing retained in some form of mechanical compression device? If so, it is/was a variable resistor to control the speed of a small universal motor. If not, it was probably a power resistor. In either case, it was designed to run very hot.Edit: It's the control element of one of thesehttp://softsolder.com/2009/03/10/old-kenmore-sewing-machine-foot-control-repair/There is a better explanation somewhere ... but I can't find it

author: TNb
author_rank: Regular Contributor
timestamp: August 03, 2014, 01:07:52 am
content: Thanks a lot! Interesting stuff

author: IanB
author_rank: Super Contributor
timestamp: August 03, 2014, 01:44:31 am
content: Quote from: TNb on August 02, 2014, 09:58:55 pmYou broke it...?
unknown apparatus - Page 1
Forum section: electronics / beginners

author: RAPo
author_rank: Super Contributor
timestamp: November 13, 2022, 01:03:16 pm
content: I got a box full of goodies. One of them was this unknown apparatus. Can someone identify what it is?It is powered by a 2x9V battery. If I switch it on, only the upper display lights up.If I put a 5V on the black/red terminals I can change the upper display by turning the left knob.Yellow/Green terminals and the right knob seem to be not working.The blue PCB got an op295 ic on it.

author: tooki
author_rank: Super Contributor
timestamp: November 13, 2022, 04:45:33 pm
content: Well, the left knob is labeled “input voltage” and the right knob “display voltage”.The output rating in mV/V makes me assume it’s scaling some signal.Are you sure the right knob isn’t just locked? The black thingie on the skirt of the turns-counting dial is a lock. You slide it one way or the other to lock/unlock.“Ein” and “aus” mean “on” and “off”.

author: tooki
author_rank: Super Contributor
timestamp: November 13, 2022, 05:05:41 pm
content: A bit more googling and I’ve figured out that DMS is the abbreviation for the German word for a strain gauge (Dehnungsmessstreifen).So perhaps it accepts an input voltage and a) scales it down to a tiny voltage to simulate a strain gauge, and b) lets you adjust the display so it matches the force or weight in kg or newtons or whatever.

author: tooki
author_rank: Super Contributor
timestamp: November 13, 2022, 05:13:02 pm
content: If you Google “strain gauge simulator” you get things with similar specs and 4 banana jacks.

author: RAPo
author_rank: Super Contributor
timestamp: November 13, 2022, 05:31:03 pm
content: At mid-school, I didn't have the highest grades for German, but I could decipher the scriptureThe knob at the right is not locked.

author: RAPo
author_rank: Super Contributor
timestamp: November 13, 2022, 05:32:29 pm
content: Ah to is a good pointer. Now the problem reduces to why the 2nd display isn't showing anything. Thanks!.
Unknown Bridge rectifier - Page 1
Forum section: electronics / beginners

author: netmike
author_rank: Newbie
timestamp: August 15, 2015, 11:09:06 am
content: Hi everyone,I have a faulty bridge rectifier ic (from an iMac power supply) that I have some difficulties tracking down. It's labeled: "T4KB80F" and then "0N15". Google seems to not know about this part. I thought On Semiconductor could have made it but a search there came up empty. I will attach a photo of it.Many thanks/Mike

author: ovnr
author_rank: Frequent Contributor
timestamp: August 15, 2015, 11:24:49 am
content: Protip: Try removing digits/characters from the end of a part number and searching again. A quick google for "T4KB80" led me tothis Alibaba seller, who also listed a different part number: GBU408. That yieldsthis datasheet; also, pictures of a GBU408 look a lot like your own part, which is pretty obviously a cheap knockoff.Also, this is just a bridge rectifier. Just go with a slightly overspec'd model when replacing it.

author: TheElectricChicken
author_rank: Frequent Contributor
timestamp: August 15, 2015, 11:54:27 am
content: Just use any other rectifier you think is bigger. Look on the back of the whatever it is in and check the power consumption. if you can guess the voltage that is used, then you can get an idea of the current.To be safe and fast, just get the largest rectifier that will fit into the device and use it. Done. big rectifiers cost about $1 or $2. It's a generic part so there is no need to match it except to make it as big or bigger in the current handling department. nothing else matters.Salvage one ! or use big diodes is fine too.

author: TheElectricChicken
author_rank: Frequent Contributor
timestamp: August 15, 2015, 11:55:53 am
content: here it ishttp://www.aliexpress.com/store/product/Genuine-original-T4KB80-4-a-bridge-rectifier-800V-quality-assurance-10pcs-lot/1682311_32280599874.html

author: netmike
author_rank: Newbie
timestamp: August 15, 2015, 05:42:51 pm
content: Many thanx!/Mike

author: TheElectricChicken
author_rank: Frequent Contributor
timestamp: August 15, 2015, 06:00:05 pm
content: Quote from: netmike on August 15, 2015, 05:42:51 pmYou're welcome.
Unknown BT Module - Page 1
Forum section: electronics / beginners

author: xoom
author_rank: Regular Contributor
timestamp: July 28, 2018, 07:59:07 am
content: Hi, can some tell me what module it is where i can check pinout and try configure it how i needIt have CHIPSET: BEKEN BK3231Qits from ELM327 diagnostic scanner i want to try use for DPS5015 power supplySome pins i figured out from ELM327 scanner but to reprogram i think need more pinsThank you.

author: bloodhunter007
author_rank: Newbie
timestamp: July 30, 2019, 06:21:07 am
content: Quote from: xoom on July 28, 2018, 07:59:07 amdps5015 communication version have own BT board, you should not use other BTand for your DPS5015 have commnunication function or not ?

author: brainstorm
author_rank: Regular Contributor
timestamp: July 18, 2020, 02:18:41 am
content: Here you have some info and poking around about the Beken, follow the sub-threads for more information:https://mitxela.com/forum/topic/beken-bk3231
Design a circuit from input-output characteristics - Page 1
Forum section: electronics / beginners

author: fourierpwn
author_rank: Regular Contributor
timestamp: September 21, 2017, 02:20:43 pm
content: Hi all,I am trying to understand what is happening in the image below and how to design a circuit based on these characteristics. Any help would be appreciated.There is no example circuit for this and very little info given.

author: fourierpwn
author_rank: Regular Contributor
timestamp: September 22, 2017, 04:14:56 am
content: My main question is what is meant by V1, 2V1, 3V1 etc. I feel one needs to think in terms of a circuit whose transfer function is a sinusoid with time-period dependent on V1.A circuit whose input-output relation is,Vout = V0*Sin(2*pi*Vin/V1)I could be wrong.

author: Ian.M
author_rank: Super Contributor
timestamp: September 22, 2017, 05:57:17 am
content: Replace the phrase 'sinusoid with time-period dependent on V1' with 'a sinusoidal function of V1' and you've nearly got it, except for an extra factor of two you shouldn't have, so the formula is:Vout=V0*Sin(pi*Vin/V1)Also the output is only specified over the Vin range 0 to 4*V1, which is important when you need to design a real-world implementation.A simulation based on the mathematical transfer function is trivial (LTspice sim attached), but a real world circuit without using digital processing would be a *LOT* harder.Lets suppose the input is a linear ramp ovwer the range 0 to 10V in time 4T. The desired output is a sinewave of period T.One possible approach would be to convert the linear ramp to a triangle wave then apply that to a sine shaper circuit. The conversion to a triangle wave would be made by inverting it, and appliying the original and the inverted voltage through various weighting resistors and clamps to a summing amplifier. The first section is just proportional to Vin, the next adds a component of -2*Vin above V1/2 to give the down slope needed between V1/2 and 3V1/2 etc. Then its just a very carefully biassed diode and resistor network that provides the sine shaping and an output buffer amp.An alternative approach would involve a sinewave generator at a frequency a couple of orders of magnitude higher than the maximum input frequency, a circuit that generates a pulse on every other rising zero crossing, feeding a linear voltage controlled delay, that outputs a pulse to a sample and hold circuit to pick off the required output level from the sinewave.I wouldn't build either on a bet, as an ADC addressing a lookup ROM feeding a DAC would be far more practical, and if the resolution and update rate is low enough, it could all be done in a small MCU.

author: fourierpwn
author_rank: Regular Contributor
timestamp: September 22, 2017, 08:05:06 am
content: Quote from: Ian.M on September 22, 2017, 05:57:17 amYou're right. My mistake.You presented two interesting approaches. However, the problem states that particular MOSFET models are to be used and there is no mention of what other devices are acceptable so I am not sure if the use of op amps is allowed or not.I'll have a bit more of a think about it.Thanks for your response Ian.M
Unknown Component - Page 1
Forum section: electronics / beginners

author: 2X
author_rank: Frequent Contributor
timestamp: May 05, 2018, 05:40:17 pm
content: Hello,does anyone knows what component is this at elow images? I measured on capacitor range with the multimeter and shows O.L. and I measured on resistor range with the multimeter and shows approximately 6,7ohm. The colors on it are:brownwhite (on top)red (on top)gold

author: ggkios
author_rank: Newbie
timestamp: May 05, 2018, 06:24:36 pm
content: It is a coil of some value

author: ggkios
author_rank: Newbie
timestamp: May 05, 2018, 06:26:22 pm
content: Quote from: ggkios on May 05, 2018, 06:24:36 pmInductor is a better fit actually.

author: 2X
author_rank: Frequent Contributor
timestamp: May 05, 2018, 06:37:13 pm
content: Thanks a lot for the reply,I found the below sites which shows how is the colour code of the inductors.http://coil32.net/design/color-marking.htmlhttp://coil32.net/online-calculators/inductor-color-code-calculator.html

author: GerryBags
author_rank: Frequent Contributor
timestamp: May 05, 2018, 06:39:11 pm
content: Try warming it up while measuring the resistance, it may be a thermistor. 6.7 Ohms seems like too much for a tiny inductor to me.

author: Zero999
author_rank: Super Contributor
timestamp: May 05, 2018, 08:20:49 pm
content: Quote from: GerryBags on May 05, 2018, 06:39:11 pmYou could be right about it being a thermistor, but wouldn't say a series resistance of 6.7Ω is unreasonable. It depends on the the value. The colour code suggests 1.9mH, which isn't a standard value. If it is 1.9mH, then I'd say a series resistance of 6.7Ω seems reasonable, perhaps even a little on the low side, going from data sheets of similar sized inductors.https://www.rapidonline.com/pdf/64730.pdfhttp://katalog.we-online.com/pbs/datasheet/7447462152.pdf
unknown component help - Page 1
Forum section: electronics / beginners

author: Vincenzo
author_rank: Regular Contributor
timestamp: May 21, 2021, 02:50:20 am
content: It measures as a Si NPN BJT with base in the middle. I need help finding it's datasheet. Tried the famous websites.

author: bob91343
author_rank: Super Contributor
timestamp: May 21, 2021, 03:02:22 am
content: Where did it come from?

author: Vincenzo
author_rank: Regular Contributor
timestamp: May 21, 2021, 04:35:32 am
content: If I knew, problem solved, but I don't. It's from a salvaged components I had for a long time

author: bob91343
author_rank: Super Contributor
timestamp: May 21, 2021, 04:51:32 am
content: How many do you have? If only one or two, I would scrap them. But if you have a drawer full, it might pay to investigate further.

author: Doctorandus_P
author_rank: Super Contributor
timestamp: May 21, 2021, 05:26:04 am
content: You can do some measurements yourself.It you've got an adjustable high voltage source, you can use a series resistor to find it's breakdown voltage (It will start acting as a zener about 20% or 30% over it's rated voltage.)If you puch too much current through it then Hfe will start decreasing.Dong a few of such measurements can be educational, but for other purposes, why bother? You can get assortments of some 600 transistors for EUR10 or less.

author: bdunham7
author_rank: Super Contributor
timestamp: May 21, 2021, 06:35:55 am
content: Perhaps a Motorola (now Freescale) SPS233 aka 2N3643.https://datasheetspdf.com/pdf-file/571071/CentralSemiconductor/2N3643/1Medium-voltage NPN 250MHz hFE 100-ish.

author: Vincenzo
author_rank: Regular Contributor
timestamp: May 21, 2021, 08:43:23 am
content: Quote from: bob91343 on May 21, 2021, 04:51:32 amI don't scrap anything. I love my stuff(It's not about this specific component, but I am hoping that someone out there has a general advice....other than throwing stuff away)

author: Vincenzo
author_rank: Regular Contributor
timestamp: May 21, 2021, 08:50:27 am
content: Quote from: Doctorandus_P on May 21, 2021, 05:26:04 amWho is EUR10, is that the name of a star trek spaceship?The main use for a discrete component (for me) is to know the maxima (power, frequency, ...etc) and those cannot be measured because if you exceed them, you will damage the componentThanks

author: Vincenzo
author_rank: Regular Contributor
timestamp: May 21, 2021, 08:54:48 am
content: Quote from: bdunham7 on May 21, 2021, 06:35:55 amAh, so you took the 3 digit number (just curious). The four digit one is a date? there were no transistors in the twenties and thirties, there was vacuum tubes and communism and fascism (too small to be a tube)

author: Hydrawerk
author_rank: Super Contributor
timestamp: October 23, 2021, 07:45:16 pm
content: Hello, can someone recognise this? Is it a LED module or what? I saw it in a clearance sale, I did not buy it so I cannot do any measurements. Google did not help.EDIT: There are only four pins!

author: amyk
author_rank: Super Contributor
timestamp: October 23, 2021, 09:35:26 pm
content: ^ Yes, some info here (may need to use translator):https://teron.online/index.php?showtopic=2024703
Unknown Component  - Page 1
Forum section: electronics / beginners

author: alin_im
author_rank: Regular Contributor
timestamp: July 30, 2015, 06:11:28 pm
content: Hi guys,I take apart today a anti mosquito plugs (https://www.google.ro/search?q=anti+mosquito+plug+in&espv=2&biw=1366&bih=643&source=lnms&tbm=isch&sa=X&ved=0CAYQ_AUoAWoVChMIseLkp7iDxwIVxTsUCh0-Mg5H#tbm=isch&q=anti+mosquito+plugs&imgrc=YBPhyvG_TDI9VM%3A) and I find some unusual parts that look like resistors but they don't have any marks on it. They are used to heat up the anti mosquito tables. The component was marked on the pcb with J1, J2Any ideas what they are

author: jeroen79
author_rank: Frequent Contributor
timestamp: July 30, 2015, 06:55:30 pm
content: If they are used for heating then they probably are resistors.

author: Mephitus
author_rank: Regular Contributor
timestamp: July 30, 2015, 06:57:29 pm
content: They are carbon-film resistors.

author: alin_im
author_rank: Regular Contributor
timestamp: July 30, 2015, 08:23:08 pm
content: Quote from: jeroen79 on July 30, 2015, 06:55:30 pmThanks I thought they are resistors but i did not check
Unknown connector - Page 1
Forum section: electronics / beginners

author: augustol
author_rank: Contributor
timestamp: January 14, 2022, 02:47:49 pm
content: So, a friend of mine owns a Sony all-in-one audio system. Recently he changed the layout in his listening room and suddenly the cable that connects the speakers to the system is a bit too short. The official extension cord sold by Sony costs a fortune. Recently he found on AliExpress a cable for his system but it has the female plug and no male on the other end. And still a bit expensive.So, I wanted to know if anyone recognize this connector to see we are able to find it (hopefully cheaper) and make a cable the size he needs (which is actually something around 30-40cm).I sugested to him to simply cut the cord and solder a wire in between the connector and the other end of the speaker wire but he is that kind of guy that will do everything he can in order to keep it original (and I can undestand that).This is the cable sold by AliExpress:https://pt.aliexpress.com/item/32911020842.html?gatewayAdapt=glo2bra&srcSns=com.whatsapp.w4b&spreadType=socialShare&bizType=ProductDetail&social_params=20443948938&aff_fcid=b2d08ce92a694d8f8bdfbc9ad89aedeb-1642171573948-08319-_msneF9Q&tt=MG&aff_fsk=_msneF9Q&aff_platform=default&sk=_msneF9Q&aff_trace_key=b2d08ce92a694d8f8bdfbc9ad89aedeb-1642171573948-08319-_msneF9Q&shareId=20443948938&businessType=ProductDetail&platform=AE&terminal_id=ac0e7c927049441a915866b605f3d1b3EDIT:Maybe it's a proprietary thing? I don't know, but I don't think so.

author: gamalot
author_rank: Super Contributor
timestamp: January 14, 2022, 04:26:25 pm
content: Read the user manual, page 17:https://www.sony.com/electronics/support/res/manuals/4248/42484501M.pdf

author: augustol
author_rank: Contributor
timestamp: January 14, 2022, 04:43:35 pm
content: Quote from: gamalot on January 14, 2022, 04:26:25 pmyeah, but no.the unit owned by my friend is a GTR888 which has the same connector but the cable is not detachable like this user manual you show here. that's why I would need a male and female connector in order to make an extention cord.EDIT:In the schematic diagram of the GTR888, it is reffered as TB4000 which has a part number 1-820-067-21. Is there a place where I can cross this part number and find the plug?

author: Kim Christensen
author_rank: Super Contributor
timestamp: January 14, 2022, 05:22:54 pm
content: I noticed that AliEx also sells the bare connector. Why not just make a longer cable and put the stock one in a drawer?

author: tooki
author_rank: Super Contributor
timestamp: January 14, 2022, 10:39:22 pm
content: Why not extend the bare end using Wago clips? No soldering, no need to find exotic connectors.
Unknown Diode - or how to identity tiny components ... - Page 1
Forum section: electronics / beginners

author: bitman
author_rank: Unknown
timestamp: February 12, 2018, 01:32:13 am
content: I'm going through a small mess of random components ... I came across this diode (?) which has no markings what so ever, other than the band (orange?) indicating the polarity. What's the proper procedure for figuring out what kind of diode this is? And yes, this is taken with very high magnification - it's a very tiny thing just 1-2mm long. I guess printing doesn't fit on such a small sucker, so does that mean you're out of luck?

author: Stray Electron
author_rank: Super Contributor
timestamp: February 12, 2018, 05:26:50 am
content: The best device for identifying unknown components is a curve tracer IMO. The shape and nature of the curve will tell you exactly what the component is and will tell you at a glance if it's resistive, inductive or capacitive and if it's non-linear. I have a Tektronix 575 with the HV option but 99% of the time I use my little B&K 540 since all I'm looking for is the characteristic curve and not the exact values.The 575s are huge but if you have the room try to pick one up and learn to use it. I paid $25 for mine at a hamfest because no one wanted it due to the size and the owner wanted it GONE. It's actually a hell of a good instrument.A picture of a Tek 575 from an online auction site.

author: mixiom
author_rank: Contributor
timestamp: February 19, 2018, 04:58:42 pm
content: Maybe a so called "component tester" from ebay for ~8€ can help you. It identifies all sorts of components and displays their cardinal values.

author: Jwillis
author_rank: Super Contributor
timestamp: February 20, 2018, 09:00:31 am
content: Hope this helps.I ran into old ones like this working on a Power Mixing Amp.
Unknown electronic symbol - Page 1
Forum section: electronics / beginners

author: Str1ker
author_rank: Contributor
timestamp: March 25, 2020, 10:55:54 am
content: Hi to all!I am currently working on integrating a MEAS 3038 6000 accelerometer in my project and cannot find any information to the electronic symbol, that is shown in the example circuit of the sensors operating manual. Does someone of you know what it stands for? I thought it has to be some kind of diode but cannot find the symbol on any online symbol catalogue

author: fabiodl
author_rank: Frequent Contributor
timestamp: March 25, 2020, 10:57:50 am
content: maybe a zener diode used as a voltage reference

author: RoGeorge
author_rank: Super Contributor
timestamp: March 25, 2020, 10:59:18 am
content: That symbol is for a Zener diode.

author: newbrain
author_rank: Super Contributor
timestamp: March 25, 2020, 01:29:47 pm
content: The symbol is for a Zener, though the "REF" makes me think to something like aTL431, even if the third terminal is not shown: for 2.5 V it would be shorted with the cathode.

author: Zero999
author_rank: Super Contributor
timestamp: March 25, 2020, 01:55:25 pm
content: Quote from: newbrain on March 25, 2020, 01:29:47 pmI agree. The LM336-2.5 sounds like a reasonably guess.http://www.ti.com/lit/ds/symlink/lm336-2.5-n.pdf

author: Str1ker
author_rank: Contributor
timestamp: March 25, 2020, 06:13:06 pm
content: Quote from: Zero999 on March 25, 2020, 01:55:25 pmThe LM316-2.5 seems to be the perfect diode for the job. Thank you!
Unknown EPROM - Page 1
Forum section: electronics / beginners

author: Cauf
author_rank: Newbie
timestamp: July 13, 2024, 05:35:49 pm
content: Hello I found this unknown ( for me) EPROM in my 1992 car's ECU. Anybody has some info on this one ? Grts Patrick

author: BrokenYugo
author_rank: Super Contributor
timestamp: July 13, 2024, 05:48:14 pm
content: Custom numbers are common in ECUs, I'd guess pin count and PCB layout should give enough clues to dump it as a 27Cxxx.

author: Cauf
author_rank: Newbie
timestamp: July 13, 2024, 05:58:56 pm
content: Quote from: BrokenYugo on July 13, 2024, 05:48:14 pmYou could be correct. Here is my info on this ECU.The MSA-11 ECU is used in older cars like a BMW e36 325TDS which also will be the example. Ithas two 27C256 EPROM's inside (UV-erasable). The EPROM's are mounted in sockets, so nosoldering is needed. On the EPROM with the lowest software number are the limitation maps,drivers wish and the quantity adjuster map. The EPROM with the higher software numbercontains the Beginning of injection maps (3 the same maps in this case). Sometimes otherEPROM's are used like the 87C257 (UV-erasable). The MSA-11 is used in the following cars:

author: m k
author_rank: Super Contributor
timestamp: July 16, 2024, 04:03:43 pm
content: Since you know their internals you also know how to read them.First row has -20, that's an access time of 200ns.So practically any current pin compatible will do.I'd use 28C series E2PROM.
Unknown IC - Page 1
Forum section: electronics / beginners

author: Klompenzijncool
author_rank: Newbie
timestamp: April 28, 2020, 02:44:46 pm
content: I’ve recently bought a pile of old electronics parts like resistors, rectifiers, capacitors, switches etc. There was also a strange looking IC in it. Can someone tell me what IC this is. Couldn’t find anything on the web and the IC contains no markings whatsoever.

author: wraper
author_rank: Unknown
timestamp: April 28, 2020, 02:48:21 pm
content: It's not IC but 7-segment LED bubble display.

author: oPossum
author_rank: Super Contributor
timestamp: April 28, 2020, 02:48:41 pm
content: 3 digit 7 segment LED display. Often called a "bubble display".

author: coppice
author_rank: Super Contributor
timestamp: April 28, 2020, 03:05:18 pm
content: It should be one of the following:A 3 digit multiplexed 7 segment LED module (most probable)A 3 digit 7 segment LED module with built in drive electronicsA 3 digit hex display with built in drive electronicsAll of these have been built into that kind of bubble display package, although, as I said above, its most likely the first thing I listed.

author: Klompenzijncool
author_rank: Newbie
timestamp: April 28, 2020, 03:09:32 pm
content: Thanks for your help. Kinda cool. I think I’m going to see if I can make this thing work...

author: schmitt trigger
author_rank: Super Contributor
timestamp: April 28, 2020, 03:20:43 pm
content: These devices were ubiquitous when the early handheld calculators still used LEDs.I remember that the HP45, TI50 and similar calculators used them.Some wrist watches too.

author: amyk
author_rank: Super Contributor
timestamp: April 29, 2020, 11:59:43 pm
content: Quote from: Klompenzijncool on April 28, 2020, 03:09:32 pmBe careful of forward current. Early LEDs were very sensitive to overcurrent.