hybridfree/eevblog-posts huggingface dataset:
Anybody recommend a buzzer that works at low voltage? - Page 1
Forum section: electronics / beginners

author: mc
author_rank: Regular Contributor
timestamp: January 11, 2014, 02:59:14 pm
content: I'm looking for a buzzer that will be reasonably loud when powered by a single cell LiPo (let's say 3 to 5V).Anybody got any experience/recommendations for such a thing?Google searches through up low battery buzzers/alarms, but I just need a reasonably loud buzzer, not a low voltage detector!

author: peter.mitchell
author_rank: Super Contributor
timestamp: January 11, 2014, 03:55:13 pm
content: with the price of the low voltage detector buzzer, just buy it and salvage the buzzer off it.

author: mdszy
author_rank: Unknown
timestamp: January 11, 2014, 03:55:48 pm
content: Quote from: mc on January 11, 2014, 02:59:14 pmYou'd probably be looking for a piezo buzzer such as this one:http://octopart.com/pb-1224pe-05q-mallory-154408The datasheet mentions it works for voltages from 4.5 - 5.5V, which should work for you.

author: Mr Smiley
author_rank: Frequent Contributor
timestamp: January 11, 2014, 04:07:49 pm
content: How loud ?Small lcd alarm clocks work at 1.5v and I’ve heard some that are VERY loud just using a piezo disk with a parallel inductor; glued on one edge of the disk and stuck anywhere inside the case.I have one that bugs me every time the alarm goes off,,,,, The battery is so week that the lcd can hardly be seen but i can hear it across the house through two rooms. It bugs me because i can't get that intensity with other similar size disks no matter what i do with them. I see it as one of those one in a million mistakes, grab the disk, dab of glue, stick it,,,,,,, that'll do and on to the next one, and never repeatable. It doesn't even have a resonance chamberIf only i could replicate its intensity with such a low supplyAnyway, every day it makes me ponderI digress,,,,,

author: mc
author_rank: Regular Contributor
timestamp: January 11, 2014, 07:17:51 pm
content: Load enough that it's quite noticeable, but not loud enough that it deafens everybody within a 5m radius!Small peize does sound like a possibility, but I was hoping for something that didn't require anything other a simple power feed.

author: SeanB
author_rank: Super Contributor
timestamp: January 11, 2014, 08:44:06 pm
content: Small piezo, inductor, one resistor and a single transistor either all in one pack or a diy kit. Take a 12V one and modify with adding an inductor instead of the resistor inside and lower the base resistor down a little.

author: tasos987
author_rank: Newbie
timestamp: January 11, 2014, 08:55:23 pm
content: According to them:http://www.buzzer-speaker.com/index.htmlThe sound strength is measured in db , 10 cm from the buzzer and is reduced about 6 db every 10 cm you are going away from the buzzer.So, in order to have deafened everybody within a 5m radius .... What should be the original strenght ?

author: Kappes Buur
author_rank: Regular Contributor
timestamp: January 11, 2014, 08:58:40 pm
content: Perhaps this onehttp://www.goldmine-elec-products.com/prodinfo.asp?number=G19709
Anyone able to explain what "ALF package" rather than "DO-35" means? - Page 1
Forum section: electronics / beginners

author: seb1982
author_rank: Regular Contributor
timestamp: May 26, 2013, 07:21:27 am
content: Hi everyone!I was looking at zener diodes on the RS website, and the one I was drawn to because of its low (5mA) test current says it comes as an "ALF" package.I'm familiar with "DO-35" packages for zeners, but I can't recall coming across "ALF" before. I can't see any standard outlines in DipTrace either.Does anyone know if it's similar to a DO-35? I mean, the dimensions are similar, so I'm guessing I don't need to treat it any differently, but I just thought I'd check!Oh, it was this diode if anyone's interested:http://uk.rs-online.com/web/p/zener-diodes/5443604/Thanks guys.

author: AndreasF
author_rank: Frequent Contributor
timestamp: May 26, 2013, 08:28:53 am
content: I'm guessing the AL in ALF stands for "axial lead", and since the data sheet actually states "Low-power voltage regulator diodes in hermetically sealed leaded glass SOD27 (DO-35) packages.", it's maybe just an abbreviation RS uses.

author: seb1982
author_rank: Regular Contributor
timestamp: May 26, 2013, 08:47:49 am
content: Yeah - I'm sure you're right - thanks.I just know if I hadn't checked it would have been something significant, though!
Anyone able to ID this quad opamp please? - Page 1
Forum section: electronics / beginners

author: Chris Wilson
author_rank: Super Contributor
timestamp: January 23, 2015, 05:50:13 pm
content: This is a now obsolete device for performance automotive usage. It takes the output from a pressure sensor and clamps the output voltage at a certain level, stopping it going higher based on the preset pot setting. The pressure sensor is run from the ECU 5V reference rail. I have found a circuit schematic of the device, and a poor quality photo of the assembled unit. Is there enough info for anyone to ID the quad op amp, which I know was a Texas Instruments device please? I wish to duplicate one for my own usage. Thanks!

author: jaycee
author_rank: Regular Contributor
timestamp: January 23, 2015, 05:57:08 pm
content: At a rough guess, looks like it might be LM248. I doubt the actual opamp is important, and any quad opamp would work.

author: KJDS
author_rank: Super Contributor
timestamp: January 23, 2015, 06:08:18 pm
content: Squinting at it, I think it could be an LM328, but it's difficult to be sure.Check which pins the supply goes to, , if it's 4 and 11, then most things would work. If you're using it in an automotive application I'd add some protection on the supplies.

author: rob77
author_rank: Super Contributor
timestamp: January 23, 2015, 06:23:09 pm
content: to me it looks like LM224 - you can safely replace it with LM324. but as mentioned above.. any quad opamp with the same pinout will just do the job

author: Rory
author_rank: Frequent Contributor
timestamp: January 23, 2015, 06:43:22 pm
content: Here's another picture, looks like an LM324.

author: gildasd
author_rank: Frequent Contributor
timestamp: January 23, 2015, 10:00:16 pm
content: It's a 324...http://pdf1.alldatasheet.com/datasheet-pdf/view/6751/NEC/C324C.htmlThe only thing that stands out is it's 3 to 30V range.

author: Chris Wilson
author_rank: Super Contributor
timestamp: January 23, 2015, 11:38:37 pm
content: Perfect, thanks very much indeed everyone. Nice find with the excellent photo!

author: SeanB
author_rank: Super Contributor
timestamp: January 24, 2015, 07:48:01 am
content: Most important is that the input common mode range includes ground, very useful on a single supply with the sensor having a common terminal on the engine block.
Strange EMF? reduction approach or random wire? - Page 1
Forum section: electronics / beginners

author: asw6
author_rank: Newbie
timestamp: May 29, 2024, 05:45:21 pm
content: Hi everybody,I recently came across this wire (see picture) that has been soldered at one end, and running parallel over a couple of resistors. What is its purpose? I assume EMF suppression, would appreciate some pointers to any information on the subject. The circuit in question is a low noise Transimpedance Amplifier, and the resistors are found on the signal input.Thanks!

author: Manul
author_rank: Super Contributor
timestamp: May 29, 2024, 09:10:32 pm
content: That does seem wrong. If that would be high frequency RF circuit, then you could maybe think that it's some weird tuning thingy, filter element, stub. But it's not a RF circuit. It could be frequency response compensation, but I really doubt that, I think that any manufaturer with at least some self respect would never implement it like that. The loose end also is not isolated and it has a hook. Like it was supposed to be soldered to something, but was forgotten? I have no idea. Perhaps reverse engineering could give an answer. Maybe you could find photos online how other devices look inside?

author: asw6
author_rank: Newbie
timestamp: May 29, 2024, 10:43:50 pm
content: I have several units, and they have all been wired the same way. I notice the end with the hook appears to have been intentionally left bare of insulation, that’s now leads me to think it might be some sort of make shift switch for testing? I will have a go at reverse engineering the circuit. The part is an Analogue Module 341-2-N which appears to be based around an OP27 op-amp.

author: Manul
author_rank: Super Contributor
timestamp: May 29, 2024, 11:11:56 pm
content: It does look, that a couple of bumps during transportation could short that loose end to the nearby node. Even if the chance is very small, it is puzzling why anyone would leave it like that.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: May 29, 2024, 11:23:01 pm
content: Most likely a gimmick capacitor. Compare capacitance of the wire to the nearby resistors, versus their value, and the resulting time constant or break frequency with respect to the amplifier bandwidth. TIAs often operate on low capacitance sources, with high impedance otherwise, and very high gain, hence the high value resistors (that's what, 100M there?), and sensitivity to mere fractional pF in the feedback network.Tim

author: David Hess
author_rank: Super Contributor
timestamp: May 30, 2024, 12:40:21 am
content: It is a gimmick capacitor made to compensate the frequency response of the high value resistor. Schematics sometimes show a line parallel to the resistor and connected to one end. Oscilloscope probes may do the same thing for their high value input series resistor or use transmission line construction.

author: Terry Bites
author_rank: Super Contributor
timestamp: May 30, 2024, 06:09:06 pm
content: Now there's a term I havent heard for while. Neutralise those damn tubes!
Anyone been playing with the LED driver SCT2024? - Page 1
Forum section: electronics / beginners

author: sbsivertsen@gmail.com
author_rank: Newbie
timestamp: March 16, 2023, 06:13:03 am
content: On page 2 in the data sheet it states that the “REXT pin is used to connect an external resistor for setting up all output current”.Does this mean that I don’t need an resistor on each LED output?http://www.starchips.com.tw/pdf/datasheet/SCT2024V01_03.pdf

author: Psi
author_rank: Super Contributor
timestamp: March 16, 2023, 06:21:56 am
content: Yep, that's how i read it.It has constant current outputs so you can connect LEDs to them directly and it will limit the current based on the config resistor on REXT.

author: sbsivertsen@gmail.com
author_rank: Newbie
timestamp: March 16, 2023, 06:41:53 am
content: Thank you for your fast response :-)This will simplify my schematic a bit.
Anyone care to explain this inconsistence ? (RF limiter data vs graph )  - Page 1
Forum section: electronics / beginners

author: ytterligare
author_rank: Regular Contributor
timestamp: April 29, 2023, 03:53:20 pm
content: Hello there, I was asking for help in another section about an HP limiter which in my opinion is broken, when I came across the specs/data and graph for another limiter I own from Mini Circuits.Being the noob I am, I am confused by the lower left graph and the data I suppose it was built upon : while given the tabulated data I can recognize the correct pattern for the 200 Khz blue curve, as the power-in increase while reaching +33 dBm, I cannot understand the correlation for the 3 Ghz red curve...e.g. : @ +33 dBm "in" from the graph I expect a max +13/14 dBm "out", while from the table I read "7.04 dBm".Where's the wrong-thinking in my reasoning ??Thank youAndy

author: Kim Christensen
author_rank: Super Contributor
timestamp: April 29, 2023, 06:11:18 pm
content: Looks like the graph on the right follows the data in the table.Might be that the graph on the left (disagrees with table) is normalized or averaged data, but they don't state that explicitly.

author: Jwillis
author_rank: Super Contributor
timestamp: April 29, 2023, 11:06:14 pm
content: Quote from: Kim Christensen on April 29, 2023, 06:11:18 pmNot adept at radio but I'm always interested in something newLeft graph Looks like an "Average ratio of change" corresponding to delta output and 1dB delta input ?

author: ytterligare
author_rank: Regular Contributor
timestamp: April 30, 2023, 09:18:57 pm
content: Quote from: Jwillis on April 29, 2023, 11:06:14 pmOk, but why not explicitly say that on the legend, as Kim pointed out ? This is Mini Circuits, not some dodgy Chinese reseller...As it is, to me it looks like the relationship between power in and power out, plain and simple...

author: Jwillis
author_rank: Super Contributor
timestamp: May 01, 2023, 04:40:48 am
content: Quote from: ytterligare on April 30, 2023, 09:18:57 pmNotesA. Performance and quality attributes and conditions not expressly stated in this specification document are intended to be excluded and do not form a part of this specification document.What can anyone say.
Anyone cascaded M5450 35 segment led drivers, or liteon LTM-8647 ? - Page 1
Forum section: electronics / beginners

author: LinuxHata
author_rank: Frequent Contributor
timestamp: April 09, 2023, 08:41:30 am
content: Hello.Got bunch of these, LiteOn LTM-8647.These are two-digit, 14 segment LED displays, which have integrated M5450 driver, which is serially driven.https://www.digikey.com/en/products/detail/liteon/LTM-8647AHR/3199181I want to use these in some of my projects, but is there a way to cascade them? For some reason, BIT32-34 are external outputs, so maybe they can be used for cascading purposes?

author: jbeng
author_rank: Regular Contributor
timestamp: April 10, 2023, 10:17:37 pm
content: I've used the mm5451 and it's LCD counterpart (mm5453) and since they have no data output pin, there really is no way cascade them, per se. The only  efficient way I know of to use several of them in a system is to tie the clock lines of all your devices together and send the data to all devices simultaneously, in a serial/parallel fashion.Here's the device block diagram from the first page of the datasheet, with the datasheet in PDF attached.

author: LinuxHata
author_rank: Frequent Contributor
timestamp: April 13, 2023, 07:11:02 am
content: Yes there is a way.Say we have 3 last (or any) outputs unused.By writing the apropriate byte sequence to them, it is possible to emulate any kind of interface output.For example, I've used outputs of PCF8575 (I2C expander) to drive APA102C leds (SPI interface).I just asked, whenever anyone done that with these ancient chips.

author: Uunoctium
author_rank: Frequent Contributor
timestamp: April 13, 2023, 09:22:34 am
content: It's not the same, but Philips realized a mux of 4 LTM8328 (4 digit version LiTeon) in PM5193 50MHz Function Generatorp. 102 in Pdfhttps://www.opweb.de/deutsch/firma/Philips/PM5193
Anyone else markup their PCBs, and map them out - Page 1
Forum section: electronics / beginners

author: lordvader88
author_rank: Frequent Contributor
timestamp: February 17, 2017, 12:28:11 am
content: Its fun, like coloring booksalso I take pictures, schematics, and layouts, and fill in info on themI should take more pictures with a camera and then map on them, since it would reduce flipping back and forth between top/bottom of circuits. 1 Serious problem with that is, like on a big PCB that flexes under its own weight when held and turn up/down/etc. I am worrying about my oscilloscope's PSU board I'm working on, it want to rest in a nice comfy boxi am using a fine tip markers and marking up a few PCBs i have, morfe to followif for any reason someone else acquires them, i will have saved them much time

author: lordvader88
author_rank: Frequent Contributor
timestamp: February 17, 2017, 11:43:14 am
content: I bought a real 1980s Sony Walkman, and its full of SMDs, and its real tight and neatly laid outIt was said to be broken, and I hoped something electrical was wrong with it, but all I found so far was that the rubber belt on is rotted away, and what a mess when I touched it, like getting ink all over hands/tools
anyone ever heared of hitano capacitors ? - Page 1
Forum section: electronics / beginners

author: Simon
author_rank: Unknown
timestamp: November 14, 2015, 08:05:53 pm
content: anyone ever heared of hitano (enterprise corp) capacitors ? I expect i was better off paying x3 for Wurth ones

author: crispy_tofu
author_rank: Super Contributor
timestamp: November 14, 2015, 09:02:05 pm
content: I have some Hitano axial electrolytic capacitors (unused) and apparently they were sold at DSE as 'general purpose caps', which is a great testament to their(apparently horrible)quality.

author: Simon
author_rank: Unknown
timestamp: November 14, 2015, 09:30:36 pm
content: yea thought so, you do get what you pay for or rather as litle as you pay for.
Anyone from frankfurt ? - Page 1
Forum section: electronics / beginners

author: mczoze1998
author_rank: Newbie
timestamp: August 13, 2015, 05:08:14 pm
content: Anyone on this forum from frankfurt ? i need to find a store near darmstadt which sells quality capsMy motherboard caps are blown and i need to replace them so i need 1500 and 3300 uF caps

author: German_EE
author_rank: Super Contributor
timestamp: August 13, 2015, 07:28:47 pm
content: I'm in Darmstadt as well. Try Zimmerman ElectronicsZimmermann Electronic Vertriebs GmbHRheinstr. 5164283 DarmstadtTel.: 06151 - 66 69-200Fax: 06151 - 66 69-280vertrieb@zeg-shop.de

author: hammy
author_rank: Unknown
timestamp: August 13, 2015, 08:29:12 pm
content: Or the EBG shop in Darmstadt (2 minutes away from ZEG)http://www.ebg-darmstadt.de/cgi-bin/lp.pl?file=start.htm

author: mczoze1998
author_rank: Newbie
timestamp: August 14, 2015, 11:40:56 am
content: Quote from: German_EE on August 13, 2015, 07:28:47 pmdankeshon
Anyone have a really old TI databook? TP4306 - Page 1
Forum section: electronics / beginners

author: timd
author_rank: Newbie
timestamp: August 27, 2011, 12:30:20 pm
content: G'day All,I have some old TI 14 pin DIPs here which I can't identify. Does anyone have access to a really old TI databook?They have the TI logo and are marked:Line 1:TP4306ANLine 2:M 7519If the second line means what I think it means it's maybe week 19 in 1975?There were some other similar TI chips 14 pin DIL marked TP4304AN/7823AET, however I was able to identify those as hex schmitt triggers.Cheers

author: Psi
author_rank: Super Contributor
timestamp: August 27, 2011, 01:03:22 pm
content: i had a quick look in my old databooks, but the only TP i could find was TP4360 in a cross reference chart.

author: lowimpedance
author_rank: Super Contributor
timestamp: August 29, 2011, 04:09:44 am
content: HiQuote from: timd on August 27, 2011, 12:30:20 pmHIJust a thought, since the TP4304AN was identified as the hex schmitt trigger (same as 7404?) then perhaps the TP4306AN is functionally the same as the 7406. Of course thats just a stab in the dark.If you have a number to hand maybe a quick breadboard hookup to test the logic function to see if its the same as the 7406!. Set the 5V PS current limit low just in case (if you can).

author: timd
author_rank: Newbie
timestamp: August 31, 2011, 12:06:03 pm
content: Quote from: lowimpedance on August 29, 2011, 04:09:44 amSounds like a plan. Will report back later.
Anyone have any experience with the PX-988 soldering iron? - Page 1
Forum section: electronics / beginners

author: unluckygamer
author_rank: Newbie
timestamp: June 08, 2018, 10:02:15 am
content: Well I was looking for a budget friendly soldering iron as I will not be going to use it too much. I was thinking on going for the TS-100, but someone recommended me the PX-988 which for the price seems to be a steal. The thing is that I want to know if someone has any experience with it before buying.

author: MosherIV
author_rank: Super Contributor
timestamp: June 09, 2018, 09:03:12 am
content: Hi, do not know about the px-988.Found a you tube review, looks like a modified mains powered hako 888 iron without the base station.JA better option maybe Bakon 950D. A couple of reviews on this forum gives it a thumbs up.
Anyone have basic LED circuit to replace bulbs in audio components? - Page 1
Forum section: electronics / beginners

author: daiku1
author_rank: Newbie
timestamp: November 10, 2020, 04:04:18 am
content: I have a couple Sunfire audio amplifiers whose bulbs go out frequently. This got me thinking. Is there a basic circuit I can purchase/build that would allow me to replace the bulb with an led instead? Searched on the web, haven't found anything. I can see this would be useful on lots of older equipment. Any thoughts?

author: themadhippy
author_rank: Super Contributor
timestamp: November 10, 2020, 04:16:17 am
content: Theirs loads of led replacments for old lamps out there for examplehttps://www.classiccarleds.co.uk/or just use a led and suitable resistor

author: james_s
author_rank: Super Contributor
timestamp: November 10, 2020, 05:33:43 am
content: In most cases all you need is a resistor. In some cases the lamp is fed with low voltage AC and you might need a bridge rectifier and a resistor if the flicker is objectionable. You can also sometimes tap off a DC rail somewhere in the equipment instead of the original place the lamp was powered from.

author: edavid
author_rank: Super Contributor
timestamp: November 10, 2020, 06:03:17 am
content: Just look on eBay for "axial LED lamps".Here's one listing of many:eBay auction: #124154932289
Anyone Have Experience With A Flir DM93?  - Page 1
Forum section: electronics / beginners

author: JPNH20
author_rank: Contributor
timestamp: December 12, 2020, 07:29:29 am
content: Was looking to purchase a new DMM and saw someone with a new in box Flir DM93. I see they retail for about $350. I repair and rebuild vintage guitar amps and hifi equipment as a hobby. Tube and solid state.Just curious if anyone has had any positive or negative experience with one. Not sure I would utilize the logging functionality too often, but the price seems good.Thanks in advance for any thoughts or opinions! Cheers!

author: Dakkahun
author_rank: Contributor
timestamp: December 12, 2020, 08:47:00 am
content: Hi.Check this pair of reviews by Kiss Analog on Youtube comparing them to Fluke DMMs:Hope it will help you.

author: JPNH20
author_rank: Contributor
timestamp: December 12, 2020, 11:09:08 am
content: Awesome thanks for the links!I'll give them a watch today.Cheers!

author: JPNH20
author_rank: Contributor
timestamp: December 12, 2020, 01:23:54 pm
content: Seems to be a pretty robust meter. I guess for $100 I'll go pick it up. Thanks again!

author: Dakkahun
author_rank: Contributor
timestamp: December 12, 2020, 03:07:24 pm
content: Glad I could be of help.

author: JPNH20
author_rank: Contributor
timestamp: December 13, 2020, 03:20:32 am
content: Picked it up did some testing and love it. Best DMM I've owned. Much better than the Extech EX350 it's replacing. This made my week. Lol
anyone have experience with Tektronix 2213a? - Page 1
Forum section: electronics / beginners

author: eengineer
author_rank: Contributor
timestamp: October 14, 2012, 06:52:23 am
content: Just wondering what thoughts were on this analog oscilloscope, going to be picking one up tomorrow for $80. Going to be my first personal oscilloscope and first analog scope I've ever used. Currently in my third year of EE and have only used DSO, thoughts? By the way, really excited!

author: Dread
author_rank: Regular Contributor
timestamp: October 14, 2012, 07:23:28 pm
content: I have a 2430 which is an analog/DSO and an older 20MHz tek scope which I really liked. Over the years I fixed hundreds of things with both of them.The really great thing about analog scopes in the hands of "younger players" is that you really learn how to use a scope more than you will with a DSO and you also learn more about electronics as a whole because the scope requires grey matter to get results and the simplicity of operation means more time is spent on your circuit design and less time on playing around with the scope itself.That is my biggest gripe with these new DSO, you spend more time with the settings than the actual circuit.

author: eengineer
author_rank: Contributor
timestamp: October 15, 2012, 06:30:12 pm
content: yeah the main reason i wanted to get the analog oscilloscope was price and experience. At frist i was debating whether i should buy a cheap pocket oscilloscope, but from dave's videos i realized how much noise they produce and how much more beneficial an actual analog oscilloscope would be. Took me a few minutes of tinkering, but I got my new oscilloscope up and working

author: w2aew
author_rank: Super Contributor
timestamp: October 15, 2012, 06:59:48 pm
content: Very nice, looks like it's in nice shape! There's lot of videos on my youtube channel that will take you though the vertical, horizontal and triggering controls that are common to most of these Tek analog scopes.

author: eengineer
author_rank: Contributor
timestamp: October 16, 2012, 01:05:49 am
content: oh wow thanks, checking out your videos now!

author: TriodeTiger
author_rank: Regular Contributor
timestamp: October 16, 2012, 04:06:31 am
content: Ah, the brother to my 2215:I wonder what the difference is, being the same bandwidth and AFAICS delayed sweep.Brilliant scope, if that is a delayed time base control on the bottom right (not sure how that one works, mine is in seconds), you can find frequency to the .05 of a division, rather than "1.something" by eye.Alexander.

author: xyloeye
author_rank: Contributor
timestamp: October 19, 2012, 10:15:56 pm
content: My first scope. It worked great and then went into tick mode (inverter won't start because of probably a short). I think I've narrowed it down to a couple of shorted diodes in the power supply but haven't had time to replace them. I'm using a Tek 465B in like new condition and a Rigol 1052 now. Anyway for the analog audio stuff I normally do, the 2213 is great.
Anyone know a best way to reduce a battery peak voltage? - Page 1
Forum section: electronics / beginners

author: Mr 12
author_rank: Contributor
timestamp: February 16, 2016, 07:15:14 am
content: I am wanting to replace a 6V SLA battery with a 7.2V Sony camera battery.I must limit the charge peak 8.4V to a max of 7.3V and hope to not draw current after reaching the 7.3V and lower as the battery draws down.Anyone have a simple way to accomplish this small volt reduction for a short period of time or should I just draw the battery down to 7.3 volts?
Anyone know about this interface? - Page 1
Forum section: electronics / beginners

author: krandall
author_rank: Newbie
timestamp: July 25, 2025, 10:44:18 pm
content: Hello,Is there anyone who can tell me where I can find this interface in attach: wireless / bt / rs232 / charging circuit?Thanks and regards,Fabio

author: darkspr1te
author_rank: Frequent Contributor
timestamp: July 26, 2025, 07:26:00 am
content: oz robotics have it, it's the BT-JinoSunnyboy solar inverters also have a unit they sell which is almost the same. Dont know about the pinouts though.darkspr1te

author: krandall
author_rank: Newbie
timestamp: July 26, 2025, 10:42:29 am
content: Quote from: darkspr1te on July 26, 2025, 07:26:00 amI didn't find anything similar, I even sent them an email.Anyway, thanks.Fabio

author: ledtester
author_rank: Super Contributor
timestamp: July 26, 2025, 12:45:05 pm
content: The 16-pin chip looks like a MAX232 which is used to convert TTL-level serial signals (from the ESP32) to RS232 levels. So I would expect pins 2, 3 and 5 of the DB9 connector to look like this:That's all I got.
Anyone know of a good book on designing and understanding Battery chargers? - Page 1
Forum section: electronics / beginners

author: ve1nhb
author_rank: Contributor
timestamp: April 14, 2022, 02:29:37 am
content: I know some of the theory. But I want to include rechargeable batteries in my projects and I want to learn to design my own.Nelson (ve1nhb)

author: free_electron
author_rank: Super Contributor
timestamp: April 14, 2022, 03:29:27 am
content: to build a charger you need to understand the battery. start there.

author: anda3243
author_rank: Contributor
timestamp: April 14, 2022, 05:04:21 am
content: I find this datasheet very informative. One little chip, and your battery is being charged.https://www.analog.com/media/en/technical-documentation/data-sheets/405442xf.pdfOvervoltage, overdischarge and overcurrent protection circuit is often included with the battery. But can be managed with the 2 attached chips.

author: fordem
author_rank: Regular Contributor
timestamp: April 14, 2022, 12:25:40 pm
content: Quote from: anda3243 on April 14, 2022, 05:04:21 amThis is not true for all batteries - I have yet to see it on lead acid, Nicad or NiMH -or on single Lithium ion cells, yes it's common on lithium batteries that have been assembled into packs.

author: Terry Bites
author_rank: Super Contributor
timestamp: April 14, 2022, 06:16:32 pm
content: I doubt there is a book as such. I'd be reading app notes and referrence designs from TI, AD, MICROCHIP, NXP, ONSEMI... eghttps://www.maximintegrated.com/en/design/technical-documents/tutorials/4/4803.htmlRemember that batteries can be dangerous if mishandled or electrically mistreated.

author: tooki
author_rank: Super Contributor
timestamp: April 14, 2022, 06:24:36 pm
content: Quote from: Terry Bites on April 14, 2022, 06:16:32 pmOf course there are. A cursory search on Amazon finds numerous candidates.With that said, all of the needed hands-on info can easily be found from the sources you mention, without forking out big bucks for a textbook.

author: ve1nhb
author_rank: Contributor
timestamp: April 17, 2022, 02:44:39 am
content: That is the problem, there are lots of books. But I can figure switch ones are good or bad without buying them and reading them.I can build a basic circuit but I don't want to poke at something. I would rather learn from the ground up and play/build as I learn.The whole idea is to have fun learning it.
Anyone know of any commonly available USB-C PC to 9V DC IC? - Page 1
Forum section: electronics / beginners

author: Marmotta
author_rank: Contributor
timestamp: June 21, 2023, 06:48:24 pm
content: I've been trying to find a basic IC to power my device with 9V via USB-C, but all the devices from major brands I've found are far more complex than they need to be for my purposes. I want a simple IC that will take a USB-C power signal and output 9V. The only one I've managed to find is the IP2721_MAX12, which I'd be able to get from Aliexpress (https://datasheet.lcsc.com/lcsc/2006111335_INJOINIC-IP2721_C603176.pdf). Does anyone know of anything similar from one of the major chip manufacturers that I'd be able to get from Mouser/Digikey?

author: Terry Bites
author_rank: Super Contributor
timestamp: June 22, 2023, 05:27:55 am
content: Buy a ready made module.www.aliexpress.com/w/wholesale-pd-decoy-9v.html

author: CountChocula
author_rank: Unknown
timestamp: June 22, 2023, 11:21:36 am
content: If you're ok with buying from LCSC, theCH224Kworks well, has plenty of stock, and is pretty inexpensive. It can be programmed to request any PD voltage either through a set of resistors or by pulling its configuration pins high or low. (LCSC only has the Chinese datasheet, but there's anEnglishone available).Be mindful that, even though you canrequesta voltage, the PSU may be unable to supply it, so if your circuit depends on a specific configuration, you will need to watch the PG pin to make sure you're getting what you asked for. I have a PSU from Microsoft that refuses to deliver 12V, for example… I can't tell if it's a bug or a feature—CC
Anyone know the manufacturer or what this component is?  - Page 1
Forum section: electronics / beginners

author: elektronJack
author_rank: Contributor
timestamp: August 09, 2019, 10:41:29 am
content: See attachments

author: Mechatrommer
author_rank: Super Contributor
timestamp: August 09, 2019, 10:48:48 am
content: http://www.datasheet.hk/view_download.php?id=1740331&file=0371\std1na60_3380752.pdf
Anyone know the the specific name of this connector?  - Page 1
Forum section: electronics / beginners

author: The Mad Atheist
author_rank: Newbie
timestamp: April 06, 2022, 10:18:36 pm
content: https://www.aliexpress.com/item/1005001823357504.html?spm=a2g0o.productlist.0.0.3a7f1c31JQpRta&algo_pvid=255b59eb-0417-4722-a149-de5ab0404b7f&algo_exp_id=255b59eb-0417-4722-a149-de5ab0404b7f-23&pdp_ext_f=%7B%22sku_id%22%3A%2212000017747771081%22%7D&pdp_pi=-1%3B3.53%3B-1%3B-1%40salePrice%3BUSD%3Bsearch-mainSearchI waited too long to replace the battery in my Redmi Note 9S and the battery bloat put too much stain connector on the mainboard. The connector is for flex to the USB C/3.5mm/loud speaker sub-board.I want to try to get it from Digi-Key US instead of waiting for it from AliExpress.Any other stuff I need like the flex cable, battery, or sub-board can be bought from Amazon.Thx, d.
anyone know the value of this capacitor? ps3 cecha01 motherboard ylod repair - Page 1
Forum section: electronics / beginners

author: psxpetey1
author_rank: Regular Contributor
timestamp: December 24, 2020, 03:43:14 pm
content: Mine broke off and I didnt even realize it until scanning the board for the 10th time. I did the nec tokin repair. and when I did the cpu side it must have become weak because it booted 3 times and then would ylod and after I opened it again it must have fell off because Even with reflows it doesnt boot. im trying to find a donor board rn to swap it but if someone knew or could find the value/size it sure would be alot easier to just order a cap off of mouser or something.
anyone know what protocol Panasonic GH4 remote uses? - Page 1
Forum section: electronics / beginners

author: rantwhy
author_rank: Contributor
timestamp: September 23, 2018, 05:33:29 am
content: I am looking to make a homemade remote for my Panasonic GH4 camera and For the life of me I cant find anything on-line about the remote protocol.I think It may be a spin off of sony's lanC called Control-M but I cant find anymore details.Thanks in advanced!
Anyone know what this is? - Page 1
Forum section: electronics / beginners

author: Tetzly
author_rank: Regular Contributor
timestamp: February 10, 2019, 07:06:53 pm
content: When I was a kid, my parents watched Name That Tune...Can anyone identify this brown speaker looking thing? I think it might come from a hospital, or a retail environment.

author: mathsquid
author_rank: Frequent Contributor
timestamp: February 10, 2019, 08:32:50 pm
content: It looks like a portable amplified lectern. There's a speaker behind the mesh on the front. If you undo the latches on the side, it will open up and it has a gooseneck mic that attaches to it.Edit: Very similar to the thing in the photo.

author: Tetzly
author_rank: Regular Contributor
timestamp: February 11, 2019, 05:08:19 pm
content: Quote from: mathsquid on February 10, 2019, 08:32:50 pmAwesome, thank you. I was mildly interested before, now I gotta have it! I'll post an update of it's particulars if I win it...see how close you were.

author: Richard Crowley
author_rank: Super Contributor
timestamp: February 11, 2019, 05:48:10 pm
content: It doesn't look big enough to be a lecturn with built-in PA amp and speaker. From your photos it looks like a "powered monitor" from the 1960s era when that was a rather rare thing.A close-up photo of that panel on the back would be very likely to provide a more definitive answer.

author: Tetzly
author_rank: Regular Contributor
timestamp: February 11, 2019, 08:36:15 pm
content: Quote from: Richard Crowley on February 11, 2019, 05:48:10 pmIt's an online only auction. I could go view the stuff, but it's a few hours away. I'll probably buy that entire pallet for 5-10 bucks, and then see what it actually is when drive up to pay for it. The pallet came from a hospital I think, and has some other interesting looking electronic goodies on it.

author: mathsquid
author_rank: Frequent Contributor
timestamp: February 12, 2019, 12:03:54 am
content: Quote from: Richard Crowley on February 11, 2019, 05:48:10 pmI'm pretty certain that it is an amplified lectern-- a small one that is made to sit on a table for a large classroom or small meeting room. When i was a college student in the 90's my college had a bunch of them that looked like this exact model.Edit: do a google image search for "soundcraft lecternette".

author: Nusa
author_rank: Super Contributor
timestamp: February 12, 2019, 12:23:17 am
content: Looks like you called it. Here's an ebay listing of one with good pictures.https://www.ebay.com/itm/254111757377

author: Tetzly
author_rank: Regular Contributor
timestamp: February 12, 2019, 12:43:21 am
content: Quote from: Nusa on February 12, 2019, 12:23:17 amAwesome! Definitely worth 5 bucks! Thanks everyone.
Anyone know what this Laser Optic Fixture is? - Page 1
Forum section: electronics / beginners

author: joenva
author_rank: Newbie
timestamp: February 10, 2019, 11:25:53 pm
content: Help! Anyone know what this is?Thanks,Joe

author: james_s
author_rank: Super Contributor
timestamp: February 11, 2019, 12:47:44 am
content: Is that gold component a photodiode?

author: joenva
author_rank: Newbie
timestamp: February 11, 2019, 12:57:34 am
content: I believe it is, yes.Thanks,Joe

author: StillTrying
author_rank: Super Contributor
timestamp: February 11, 2019, 01:34:40 am
content: Connect it to a DVM or scope and shine a light on it, should get ~100mV ish.
Anyone know what's up with Microchip website? - Page 1
Forum section: electronics / beginners

author: paulca
author_rank: Super Contributor
timestamp: January 05, 2018, 02:18:08 pm
content: It seems all the links are dead to Microchip's website. Particularly the AVR documentation. Anytime I search for something it produces a "Page not found". Like just now:https://www.google.co.uk/search?q=atmega328p+registersProduces dozens of links to Microchip documentation, but if follow, for example:https://www.microchip.com/error.html?aspxerrorpath=/Images/Atmel-42735-8-bit-AVR-Microcontroller-ATmega328-328P_Datasheet.pdfI get a "Page not found."If I browse around their clunky menus I can eventually find most things are still there. I can only assume they uploaded a new website and Google et.al are still updating. However preserving backward compatible links would have been an awfully cool idea.On a related note, AVRFreaks have apparently blocked the include file names in their forum, so all example code has:#include#includeAt the top. It's really cheesy.Internet is broked this week

author: phil from seattle
author_rank: Super Contributor
timestamp: January 05, 2018, 02:32:13 pm
content: Yeah, I was hitting a lot of 404 links to atmel stuff found via google search in the last few days. However, use a few terms from the 404 link and search on the microchip page. It usually turns up. Microchip has been consolidating the 2 web sites, my guess is they aren't close to done. Not sure how google is getting stale data, though.

author: paulca
author_rank: Super Contributor
timestamp: January 05, 2018, 03:12:48 pm
content: The most annoying thing I've found today is that some of their internal links don't work either.I've only been delving into this stuff for the past few days, but I think it's been since about New year at least.

author: Aodhan145
author_rank: Frequent Contributor
timestamp: January 06, 2018, 12:07:51 am
content: Yeah I've been getting the same results but only on atmel parts. I think they messed up something recently. They had started to merge all the atmel parts into Microchip pages and might of moved the PDF locations. The links from google don't seem to work and the only link that does is from the product part page.

author: hli
author_rank: Frequent Contributor
timestamp: January 06, 2018, 08:30:54 pm
content: Seems to work for me,. Doing your google search takes me to the AtMega328 page:http://www.microchip.com/wwwproducts/en/ATmega328pwhere the data sheet is linked (at the bottom):http://ww1.microchip.com/downloads/en/DeviceDoc/Atmel-42735-8-bit-AVR-Microcontroller-ATmega328-328P_Datasheet.pdf

author: paulca
author_rank: Super Contributor
timestamp: January 06, 2018, 08:42:19 pm
content: Try searching for something like "AVR Assembler Timers" and follow the links.
Anyone knows these parts S20ZND06 and SC8K250ZD? - Page 1
Forum section: electronics / beginners

author: max.wwwang
author_rank: Frequent Contributor
timestamp: December 12, 2022, 07:30:36 am
content: I got this at recycle centre. It appears to be a 3-phase rectifier bridge. But strange enough I could not find the datasheets for the two parts S20ZND06 and SC8K250ZD. Both have 3 poles each, +/~/- for S20ZND06, and K/C/A for SC8K250ZD. I believe S20ZND06 is a dual diode module. No idea what K/C/A are, though K or C probably Cathode and A Anode.Also intriguing is that each pair of S20ZND06 and SC8K250ZD are connected in parallel +/K, ~/C, and -/C, which makes me thing C probably stands for "Common". Easy to understand identical parts in parallel to have higher capacity or rating (though sometimes not that simple) but here two parts are not the same.

author: max.wwwang
author_rank: Frequent Contributor
timestamp: December 12, 2022, 07:32:15 am
content: More photos.

author: amyk
author_rank: Super Contributor
timestamp: December 13, 2022, 03:38:15 am
content: Judging by Otis name I suspect this came from an elevator controller, and is likely to be a custom-marked part.

author: Halcyon
author_rank: Unknown
timestamp: December 13, 2022, 06:42:22 am
content: Duplicate post:https://www.eevblog.com/forum/repair/anyone-knows-these-parts-s20znd06-and-sc8k250zd-355807/
Anyone knows this capacitor brand - Elite? - Page 1
Forum section: electronics / beginners

author: Faranight
author_rank: Unknown
timestamp: October 01, 2021, 06:13:29 pm
content: Hey,I've recently been trying to purchase some caps for a project of mine. Normally I go searching various suppliers like Mouser, Digikey and Farnell to try and find some items with acceptable performance and price. Most caps seem rather expensive these days, but there is one brand that stands out because it is much cheaper than the rest -Elite. This brand of caps is apparently fromChinsan Electronic Industrial, Taiwan, and the store that I've found selling them was TME, an european reseller.https://www.tme.eu/en/katalog/tht-low-imped-electrolytic-capacitors_100264/I searched the website for470uF, 50V low-esr electrolytic caps. Most of them sell for about 1 EUR a piece, but the elite one is just 20 cents. The same applies for larger quantities i.e. most 100pcs orders go for 30 to 50 cents per cap while the Elite brand sells for about 16 cents each. Other cap sizes/voltages tell a similar story. They're cheapest of the bunch, but you know what they say... you get what you pay for. Also, all the EEVblog Youtube videos where Dave goes wah wah wah whenever he finds some exotic cap brand in a teardown vid have made me skeptical.So I was wondering, if anyone knows this brand and can maybe vouch for the quality? I'm not saying the brand is bad, they're just unusually cheap.Regards!EDIT: Here's the 470uF Elite cap link:https://www.tme.eu/en/details/ed1h471mnn1220/tht-low-imped-electrolytic-capacitors/elite/

author: wraper
author_rank: Unknown
timestamp: October 01, 2021, 06:21:03 pm
content: They are OK, Dell uses them almost everywhere.

author: Gyro
author_rank: Super Contributor
timestamp: October 03, 2021, 11:36:33 am
content: A bit of a generalisation, but stuff manufactured in Taiwan is normally good quality. They are more high-tech than mainland China.

author: Faranight
author_rank: Unknown
timestamp: October 03, 2021, 04:18:49 pm
content: Alight, thanks for the info.I'm buying.
Anyone knows this device? - Page 1
Forum section: electronics / beginners

author: AlphZeta
author_rank: Regular Contributor
timestamp: February 13, 2012, 12:41:07 am
content: Hi guys,I have quite of few of this three-terminal devices (removed from satellite LNBF). Unfortunately I couldn't find the datasheet for it. If you take a look at the photo below, you will see that the device has the marking of SB2940G.The table below lists the voltage drops among the pins when measured using the DMM diode range: (The device pins are 1, 2, 3 from left to right. The column represents the + lead and the row represents the - lead. So for instance, the voltage reading is 1.59 when the negative lead is connected to the middle pin and the positive lead is connected to the first pin). The voltage drop readings seem to be from two diodes connected in series but it doesn't look like a darlington though.Any advice is greatly appreciated!-+1231-inf.inf.21.59-1.5931.79inf.inf.

author: klafaille
author_rank: Newbie
timestamp: February 13, 2012, 01:30:40 am
content: The G suffix doesn't appear in it, but it's likely a flavor of voltage regulator as seen in the attached datasheet.

author: amyk
author_rank: Super Contributor
timestamp: February 13, 2012, 10:26:05 am
content: Quote from: klafaille on February 13, 2012, 01:30:40 amI agree with this. It's a Sino-Matrix SB2940 8.5V 350mA LDO:http://www.sinomatrix.com/eng/products.htmlThe part number resemblance to the LM2940 is probably not coincidence.

author: AlphZeta
author_rank: Regular Contributor
timestamp: February 13, 2012, 02:22:02 pm
content: Thanks guys! I googled "SB2940" as well but nothing meaningful came back (SB2940 returns a bunch of non-related legislation stuff). I will give it a shot.

author: DaveHardy
author_rank: Regular Contributor
timestamp: February 18, 2012, 02:03:30 am
content: Not a lot of beginners know this, but Japanese bipolar transistors are prefixed with a: 2SA, 2SB, 2SC or 2SD, and FET-s with 3S:2SA - PNP, HF transistors,2SB - PNP, LF transistors,2SC - NPN, HF transistors,2SD - NPN, HF transistors.It doesn't work in this situation because the part has already been identified by a previous poster, but sometimes you can try 2SB2940 if you are looking for a cross.