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

author: mattsully
author_rank: Newbie
timestamp: June 06, 2018, 03:33:31 pm
content: I have an electronic lock with touchpad rated for 3V and my USB powerpack keeps draining all batteries (4 AA 1.5V) within 24-48 hrs.What is interesting, is that locks I have supplied of the same design have functioned well for years...I am assuming there is leakage occurring somewhere in the PCBA.

author: Gyro
author_rank: Super Contributor
timestamp: June 06, 2018, 07:00:38 pm
content: Welcome to the forum,I suspect that you're going to need to give much more detail - internal photos, schematic, data etc. before anyone can help you, which I'm sure we will be more than willing to do.P.S. Just a hint to get you going on the forum, just look down the list of thread titles and compare the number that just say 'Help' with the ones that give something relevant to the topic. You can change it by editing your original post and just changing the title text.

author: Brumby
author_rank: Unknown
timestamp: June 07, 2018, 01:21:23 am
content: Indeed, welcome to the forum.I can only support what Gyro has said... but there is no suspicion about needing more details - it is a certainty. Even somebody intimately familiar with such locks will need some sort of additional information to know what lock you are talking about. The rest of us may be able to work out how the lock works and what might be worth checking if you give us something to look at. Photos are good, schematics are too (if you can get them).I will also suggest a better thread title. Something like "Help: Electronic lock drains batteries too quickly" will actually attract the attention of someone who might know a thing or two about electronic locks. As suggested, you can go to thefirstpost you made, click on the "Modify" button and type in a new subject line. It is the subject line of this first post that gets used for the title of the thread.
Help - Choosing a Power Supply - Page 1
Forum section: electronics / beginners

author: ZenMedic62
author_rank: Newbie
timestamp: February 03, 2020, 11:15:39 pm
content: Hello,I would really appreciate some advice I have narrowed down my choices of power supplies to two, and would like your recommendation.Rigol DP832Siglent Technologies SPD3303x-eWill be using it for home shop labThank you

author: james_s
author_rank: Super Contributor
timestamp: February 03, 2020, 11:19:00 pm
content: It would really help others if you would choose a more descriptive title for your post than "Help".What features are important to you? Does one offer something the other doesn't? Both are generally reputable low cost brands.
help inserting an image within a post - Page 1
Forum section: electronics / beginners

author: abdullahseba
author_rank: Frequent Contributor
timestamp: April 20, 2014, 12:07:54 pm
content: how do you insert a picture on a post when I click on the button all that comes is [/imgModerator: It helps if you make the subject line a bit more detailed that just 'help'

author: SeanB
author_rank: Super Contributor
timestamp: April 20, 2014, 12:14:49 pm
content: Add as attachment and then set the "Return to topic" flag. When you are back there copy the image URL and press edit, then put in the image tags, click in the middle of them and paste the URL to the forum image. Then click update and there it is.Other method is to use something like Flickr and paste the BBcode of the image into the post window. example below from my Flickr page.4004 processorbySeanB_ZA, on FlickrMt FujibySeanB_ZA, on Flickr

author: Simon
author_rank: Unknown
timestamp: April 20, 2014, 12:18:46 pm
content: uh the simple answer is that the function is for linking to an image not uploading it. As suggested you could link in an image you uploaded to the forum, but you can link in from other sites

author: abdullahseba
author_rank: Frequent Contributor
timestamp: April 22, 2014, 09:06:11 am
content: Quote from: SeanB on April 20, 2014, 12:14:49 pmI see oo ar
Philips PM3394 vs Fluke PM3384B - Page 1
Forum section: electronics / beginners

author: zecadiabo
author_rank: Newbie
timestamp: August 05, 2015, 05:03:45 pm
content: Hi,Can someone helpWhat is the best for the same price:PHILIPS PM3394orFLUKE PM3384BThanks?

author: w2aew
author_rank: Super Contributor
timestamp: August 05, 2015, 06:50:17 pm
content: The 3394 has twice the BW of the 3384, that alone might be worth tipping the scale...

author: zecadiabo
author_rank: Newbie
timestamp: August 05, 2015, 07:27:15 pm
content: Quote from: w2aew on August 05, 2015, 06:50:17 pmThanksAnd about memory sample rate? and others spec?urgent buy....ct1fsl

author: w2aew
author_rank: Super Contributor
timestamp: August 05, 2015, 09:04:34 pm
content: Quote from: zecadiabo on August 05, 2015, 07:27:15 pmBoth have single shot sample rate of 200MS/s. The 200MHz unit has a correspondingly faster timebase, and better high frequency trigger sensitivity. This is all from datasheets found online. I have no personal experience with either of these units.http://www.testequipmentconnection.com/specs/PHILIPS_PM3394.PDFhttp://www.testequipmenthq.com/datasheets/FLUKE-PM3384B-Datasheet.pdf

author: Gyro
author_rank: Super Contributor
timestamp: August 06, 2015, 11:14:08 am
content: Just a hint for the future. Using a meaningful Subject title would probably have got you a much faster response. Something like 'Philip PM3394 vs Fluke PM3384B'. An extra 30 seconds on the subject would have certainly paid off in response time particularly for an urgent buy, and be more helpful to others searching for the same answer in future.

author: zecadiabo
author_rank: Newbie
timestamp: August 06, 2015, 04:39:17 pm
content: Thank you all for help i think i'll go for the Philips.

author: helius
author_rank: Super Contributor
timestamp: August 07, 2015, 09:51:00 am
content: OP,Whether these pm-series scopes say "Philips" or "Fluke", they were made by the same company in the Netherlands.Philips N.V. and John Fluke Corp. formed an alliance in the mid-80s to develop and market test equipment, and Fluke finally bought that division from Philips in the early '90s. Both company's logos appeared on the same range of oscilloscopes, made in Eindhoven.The -B series of scopes was an update in around 1998. Expanded and more flexible memory was standard on the pm3384B, while it was only an option on the pm3394. The 3384B has lower vertical bandwidth, but this was achieved by using different passive components around the LNA, as in so many other instrument series.

author: fcb
author_rank: Super Contributor
timestamp: August 07, 2015, 10:42:31 am
content: PM3394B if you can - Fluke bought Philips T&M.

author: zecadiabo
author_rank: Newbie
timestamp: August 10, 2015, 05:35:31 pm
content: Thank you all, got the PM3394, very good scope...for 400 USD...Hope it will last for more 10 years...
help 555-circuit tv test pattern generator - Page 1
Forum section: electronics / beginners

author: aluqard89
author_rank: Contributor
timestamp: August 09, 2015, 06:25:04 pm
content: Greetings !I have been building this 555 circuit from a old 555 circuit book. Its a tv pattern generator.The problem is it does not work the picure is like out of phase, scrolling and its not showing up as the pattern illustrated in the circuit i attached. Could it be some kind of delay ?anyone have a clue why it wont work?i have adjusted the pots for the PAL frequencys.ic1: 555 15.625 kHzic2: 555 50 hzic: 74LS00 tried with 74HC00ic4: 74HC132

author: Andy Watson
author_rank: Super Contributor
timestamp: August 09, 2015, 09:21:52 pm
content: How are you connecting the TV to your circuit?

author: ElectroIrradiator
author_rank: Frequent Contributor
timestamp: August 09, 2015, 09:41:48 pm
content: There is no hardware synchronization between vsync and hsync, so it pretty much *has* to drift.Hsync *needs* to be at the very least a constant (an integer value would be gravy) multiple of the vsync signal for the image to be stable, and that *requires* that the line freq oscillator is slaved/reset by the frame oscillator.So the widget is fundamentally broken, and the article is lying.
Help a Noob: RD6018 Benchtop PSU - 800w PSU? - Page 1
Forum section: electronics / beginners

author: McAdam
author_rank: Newbie
timestamp: February 13, 2021, 10:33:31 pm
content: Ill try to keep this short.I am in need of a benchtop PSU to serve many different functions including basic electronics using ESP32s etc... AND Charging large batteries including 48v LiFePo4 packs.I have used the Riden 5005 in the past, and am now looking at getting the RD6018.The bundled PSU is a 65v 800w (12.3A) Switching power supply.My question is related to the nature of Switching Power Supplies and how it affects things when bucking the voltage:Using the bundled switching power supply, what would be the limiting measurement for use, I.e.Can I use 800w throughout the voltage range - 24v @ 33.3A (theoretically if the RD6018 didn't have its limit of 18A)OR would the Amps become the limit, allowing only 12.3A across the voltage range - 24V @ 12.3A = 295wI know it would be best to go for a 65v 1200w power supply, but there's nothing in the similar price range and nothing that doesn't remind me of when I had a Dell M1000E in my living room.

author: Algoma
author_rank: Frequent Contributor
timestamp: February 13, 2021, 11:43:03 pm
content: Although you have 800W pf power available in the supply, The RD6018 will only allow 18Amps max output at any voltage you select, up to its own 800W limit, This is mostly limited by the current capacity of the components used in its design, and the 20A fuses.Provided you had a bigger buck converter capable of handling higher currents without igniting, then yes, you could convert that 800W of source power into to a 24V @ 33.3A output (in an theoretical ideal converter) Provided you stay within the 800W power limits of your source supply, and within the various capacities of your converter, or it will follow its overload design (Drop output voltage / Hiccup / blow fuse / Ignite, or all of the above in the case of cheap supplies).Buck converters over 20A often have a fixed voltage output, for maximum efficiency, but there are a few adjustable ones that exist:https://www.aliexpress.com/item/4001352321274.html(example)

author: mvs
author_rank: Frequent Contributor
timestamp: February 14, 2021, 11:29:41 am
content: Quote from: McAdam on February 13, 2021, 10:33:31 pmRD6018 has around 1600µF capacitance at the output. It is fine for some power electronics applications, like driving motors and battery charging. But it is a way to high to serve as normal lab supply. Good linear supplies can have 10µF or even less.Quote from: McAdam on February 13, 2021, 10:33:31 pmRD6018 should have efficiency of around 85-90%, so in theory you can use full 18A of RD6018 until you hit 800W*0.85=680W power draw. It is up to around 38V of output voltage. You should be able to set this power limit in RD6018 settings, so that you do not accidentally overstress your primary supply.
Help about a switching mode power supply circuit - Page 1
Forum section: electronics / beginners

author: mkvl
author_rank: Contributor
timestamp: July 03, 2023, 12:52:45 pm
content: I'm trying to made this switch power supply circuit I found on google (picture below) but as soon I connect the power 150v the resistor 12ohm burns out immediately.The transistor part number: E13007F2I appreciate any advices.

author: m k
author_rank: Super Contributor
timestamp: July 08, 2023, 12:34:09 pm
content: Capacitors are bipolar.
Help asked re early V late schematic and interpreting adjustment procedures? - Page 1
Forum section: electronics / beginners

author: Chris Wilson
author_rank: Super Contributor
timestamp: May 22, 2017, 12:47:42 pm
content: I have two elderly Farnell linear power supplies, one was in poor condition and exhibited some faults from time to time. With the forums immense help I have now fixed it, but wish to calibrate its various adjustments. The issue is I have schematics for both the earlier type, which I do NOT have, with all discrete components on the three PCB control boards, and schematics for the later versions, which I DO have, with some IC's on two of them. The only manual I have been able to locate refers to the early boards. I have managed to crack adjusting max output volts, and max output current, for which I converted the instructions for the earlier model's adjustments to reflect my own, as best I could, and both were quite a bit out...I am now pondering how to work out what P1 and P2 do on the SCR board I have, as the manual discusses, as far as I can see, a board with 4 pots on it. My board has just two multi turn pots. I want to adjust the "separation voltage" on the SCR board, that appears to adjust the relationship between the main transformers secondary voltage, under SCR control of the primary, and the output of the pass transistor assembly. The idea is to keep the energy dissipated in the huge pass transistor heat sink tunnel as low as possible.If anyone's up for more cross checking of the early and late schematics, and the "Internal Adjustments" section of the manual I will attach them as .jpg screen shots. If I could work out the function of P1 and P2 multi turn pots on the op amp inputs of my late type SCR board and check and reset the separation voltage I'd call it a day with calibrating the bruteThanks for all the help so far everyone!

author: Chris Wilson
author_rank: Super Contributor
timestamp: May 22, 2017, 12:56:26 pm
content: And here's the description of how the early version of the SCR Control Board should function:
help AT17LVxxx programmer - Page 1
Forum section: electronics / beginners

author: xcoder
author_rank: Contributor
timestamp: May 03, 2014, 11:59:23 am
content: Hi all this is my first post here i hope that it will not be a question but !!!!ok i was fixing a machine that have a configuration eeprom AT17LV256 dip-8and its blank or damaged since that replaced it with another one from a working machine and now it starts normally the problem here is that i want to read it and program it into the blank onei did some research and i found a programmer designed by a Russian guy software and hardwarehttp://www.kasatky.ru/but in his programmer he targeted a plc family of 17LVbut one i have is dip-8 type so basically its not the same and i did some effort but im confused so please if someone can help editing the schematic or something it could be very helpful from himthanks in advance and sorry if ask much and my English is bad i know

author: amyk
author_rank: Super Contributor
timestamp: May 03, 2014, 02:19:36 pm
content: From thedatasheetandprogramming specit appears to be a pretty standard AT24Cxxx compatible I2C EEPROM with some extra features, so you can read/write it like one once SER_EN is low. Search for "I2C EEPROM programmer" for more info.

author: xcoder
author_rank: Contributor
timestamp: May 03, 2014, 05:21:18 pm
content: thanks for your reply sir but the problem that im not that good with eeprom and stuff so basically what i was kindly asking if you can modify the Russian schematic to work with 8pin version of 17LV because what was in the schematic is that its for another version of the eeprom !so please im not that good and more things sad me my labtool uxp doesn't support this eeprom !!so im stucklook at schematic its about not dip-8 and whhat i have is same but in deep-8 but cant figure out what to do so please if you or someone sir can mod the schematic to work with dip-8

author: amyk
author_rank: Super Contributor
timestamp: May 04, 2014, 10:27:38 am
content: Quote from: xcoder on May 03, 2014, 05:21:18 pmThis programmer? 17LV128 is on the supported device list. Even if it wasn't, as I said above this EEPROM behaves like AT24C128 when SER_EN is low, and any programmer out there should support 24C EEPROMs.If you really want to build and use that programmer then just ignore the pin numbers and use the labels for the signals - the datasheet I linked above shows the pinout of the DIP version.Also, I'm not a "sir".

author: xcoder
author_rank: Contributor
timestamp: May 04, 2014, 02:56:42 pm
content: thanks brother its very nice from you now its workingthread \closed
Help: Black & Decker Toast-R-Oven troubleshoot - Page 1
Forum section: electronics / beginners

author: niemand
author_rank: Contributor
timestamp: September 02, 2022, 03:22:57 am
content: I have a Black & Decker Toast-R-Oven model 355 TY8 from around 2003. Suddenly the baking function stopped working. The toast function seems to work but doesn't seem to know when to end. I don't seem to notice any thermal fuse, and recapping the two canister capacitors does not help." alt="" class="bbc_img" />" alt="" class="bbc_img" />The bake function / temperature control dial appears to be a bi-metal switch. I measured the resistance between the two contacts (A and B) to be less than 1 Ω." alt="" class="bbc_img" />Any suggestions as to how to troubleshoot?Thanks.

author: niemand
author_rank: Contributor
timestamp: September 02, 2022, 03:47:56 am
content: Is the round rotating object on the bi-metal switch some sort of variable resistor? Could it have gone bad?
help buy ziplock aliexpress for protect my electronics - Page 1
Forum section: electronics / beginners

author: johnrodrigues
author_rank: Newbie
timestamp: August 15, 2020, 12:00:45 pm
content: could you indicate on Aliexpress good quality ziplock bag to store my electronic devices and DVD discs and protect them from moisture? I have silica gel but I don't know which ziplock to buy but the bag size is on average 22x32cm

author: tooki
author_rank: Super Contributor
timestamp: August 15, 2020, 01:48:10 pm
content: Assuming we are talking finished goods and not components, I’d actually go with good quality freezer bags from your grocery store, as they’re designed to keep liquids in. (Most non-food ziplock bags are not entirely watertight, which you want when keeping things dry.) Ideally, you’d put the electronic gadgets into a silver antistatic bag first with the desiccant, and then put that into a freezer bag. Or even vacuum seal it if you have the sealer and it’s for long term storage.For components, you definitely want the silver antistatic bags. Either a quality one if you’ll use it alone, or a cheaper less airtight one if you’ll double bag it.

author: TimFox
author_rank: Super Contributor
timestamp: August 15, 2020, 03:31:02 pm
content: In the US, my go-to source for ziplock bags (regular, labeled, and antistatic) in a very wide variety of sizes is McMaster Carr, the source of all good things.https://www.mcmaster.com/plastic-bags/press-to-close-bags/Grocery-store bags are fine (unless you need antistatic), but are available in a much smaller set of sizes.

author: Simon
author_rank: Unknown
timestamp: August 15, 2020, 03:35:58 pm
content: Quote from: johnrodrigues on August 15, 2020, 12:00:45 pmHave you finished? or shall I just ban you? link to aliexpress come to a signature in this thread soon?
Help choose a mosfet driver - Page 1
Forum section: electronics / beginners

author: nandoanalog
author_rank: Contributor
timestamp: May 03, 2016, 02:58:28 pm
content: I'm trying to drive a power mosfet (irls3034 7p) from an arduino at frequencies up to 40khz. Is there a driver that takes the 5V from the arduino output, and transforms it to 10 or 12V?
Help choosing a Backlight WLED Driver for a 7" LCD - Page 1
Forum section: electronics / beginners

author: IvanIlievMCU
author_rank: Newbie
timestamp: December 06, 2020, 01:25:51 pm
content: I've been looking for a constant current WLED driver to power up the backlight of a 7" LCD.I've gone through the datasheets of most of TI and some other manufacturers' drivers but they're only capable of driving UP TO to some ammount of LEDs (Typically 6-10) in series or some other configuration like 9 Strings x 3 LEDsThe problem i'm having is that none of the LCDs i'd like to use have such backlight LED configurations.Will TPS61165https://www.ti.com/lit/ds/symlink/tps61165.pdf?HQS=TI-null-null-mousermode-df-pf-null-wwe&ts=1607158544643&ref_url=https%253A%252F%252Fwww.mouser.it%252Fdo the job with an input of 5V.What am i missing or doing wrong?
Help choosing a buck-boost controller IC - Page 1
Forum section: electronics / beginners

author: John_Hofmeyr
author_rank: Contributor
timestamp: November 12, 2017, 03:01:37 am
content: Hello Everyone,I have been working on building a bench power supply based on a buck-boost converter. For the past few months I have been playing around with MANY different IC's and different designs. Unfortunately, almost none of them have worked, and the ones that did give me an output were either terribly unstable, far to clunky and complex, or they weren’t able to supply the kind of power that I’m looking for. In the design of my PSU I have a big toroid transformer supplying 12v AC to a full bridge rectifier and then through some filter caps with a resulting output of about 15v DC. I want my PSU to output between 0 (or close to 0) to 35V and I want a maximum current output of 10 Amps (obviously not at 35v). The total power output I want is about 120 - 150W (or 12v @ 10A and 35v @ 4A).Anyway, I need help finding an easy to use controller IC that I can use to build a buck-boost converter that will give me an adjustable voltage and adjustable current output. If you have any tips for me and/or you know of an IC that I can use then your advice would be much appreciated!Thanks!
Help choosing a capacitory for 3.3v circuite - Page 1
Forum section: electronics / beginners

author: sairfan1
author_rank: Frequent Contributor
timestamp: October 18, 2023, 04:21:39 pm
content: I was looking for SMD 0805 10uF capacitor for my 3.3v circuite, when I searched mostly capacitors I found were 10uF 50v I want to know does it still work or its big difference I believe closest I can found could be 6.3v. I wanted to learn how capacitor voltage can impect when supply voltage is way below.I will be using those capacitors close to VDD/VCC line of different ICs.

author: Kleinstein
author_rank: Super Contributor
timestamp: October 18, 2023, 04:45:37 pm
content: The voltage rating for capacitors is the maximum allowed voltage. Using a capacitor with a higher voltage rating is no electrical problem. The higher voltage ones tend to be more expensive and mechnical larger though, but there is also a question what is available and used in numbers.10 µF is already quite a large capacitor for decoupling, depending on the chip (especially logic, OPs, low power µCs) less capacitance may be enough.

author: Zero999
author_rank: Super Contributor
timestamp: October 18, 2023, 07:01:12 pm
content: What sort of capacitor is it: ceramic, tantalum, aluminium?Most large value ceramic capacitors, in a small package, saturate at a relatively low voltage, compared to their ratings. This means that the capacitance drops, as the voltage increases. A 50V 10µF ceramic capacitor will not have a capacitance anywhere near 10µF at 50V, or even 30V, but at 3.3V, it'll definitely be 10µF. In other words, if it's ceramic, then I would definitely recommend using a 50V ceramic capacitor on a 3.3V rail.If it's an aluminium electrolytic capacitor, then this isn't an issue, but a 50V part on a 3.3V rail wouldn't be a problem.Tantalum capacitors have a tendency to smoke when used close to their voltage ratings, especially when subject to high current surges/ripple. Going for 50V is still overkill, but won't do any harm.

author: alligatorblues
author_rank: Regular Contributor
timestamp: October 19, 2023, 01:35:20 am
content: My rule for tqntalum is double the voltage you need.

author: Vovk_Z
author_rank: Super Contributor
timestamp: October 19, 2023, 02:22:11 pm
content: Quote from: sairfan1 on October 18, 2023, 04:21:39 pmThere are several topics about it here.

author: sairfan1
author_rank: Frequent Contributor
timestamp: October 19, 2023, 04:20:16 pm
content: its ceramic capacitor, thanks for the explaination.
Help Choosing MOSFET from a Datasheet + 2 Follow Q's - Page 1
Forum section: electronics / beginners

author: cb900
author_rank: Newbie
timestamp: March 03, 2021, 05:26:42 pm
content: Just joined - hello everyone.I really struggle with MOSFETs be gentle!!I would like to use the MAX16914/16915 (link below) for a marine (diesel automotive) based project.With the addition of TVS's etc I'm looking to smooth, filter, protect etc the downstream 'stuff' from the 12-240Vac inverter and a 12pole alternator. crap on the 12Vdc lines feeding the cabins main fuseboard and subsequently onto various voltage regulators etcMy max dc calculated current draw is circa 38A so 45A+ design value. Given the information in the included data sheet would someone be kind enough toexplainhow I determine a suitable P-Channel device. I have found various devices with low RDSon and suitable continuous current carrying capabilities but now I'm stuck.Additionally, the devices I have found are SMD and no mounting tab suggestions on PCB mounting - I'm tempted just to solder wire to legs and then heat shrink for the main connections and just solder onto PCB just to hold device rigid and use PCB mounting holes to screw it to something .Lastly, my 'gut' says I should included/consider a series inductor - without any hard noise data how might I choose oneThank you
help choosing power supply for logic board testing - Page 1
Forum section: electronics / beginners

author: sheridansystems
author_rank: Newbie
timestamp: February 26, 2014, 11:02:44 am
content: Great forum!Being new to the field, and setting up my lab I need help finding a compatible bench power supply for testing Macbook Pro's logic boards. My Rigol ds1052 is on the way and I understood that if I power a logic board with a retail Apple adapter it will not work due to the third prong to earth connection? I use an Apple magsafe power adapter and a multimeter to test general voltage, resistance ect... The magsafe adapter is 85w with an input of 100-240V 15.A 50-60 Hz and an output of 18.5v=4.6a and 16.5v=3.6a. I want to power the boards safely to further diagnose failed SMD's, components, connectors and or traces using my Rigol. Any help is greatly appreciated.Thank you

author: ielektros
author_rank: Unknown
timestamp: June 28, 2014, 08:00:03 pm
content: Hi. Old post. May you have an answer too.But my experience is. I have a cable, cutter from a dead old magsafe charger. The cable inside have the magic. Not the charger. I use that cable connected with my Agilent PSU and working like a charm. OSX System profiler show that is a 60W MagSafe original charger. That means, the plug have the one wire chip inside. Not the charger.
Delete Delete Delete - Page 1
Forum section: electronics / beginners

author: The_Almighty_Bacon_Lord
author_rank: Contributor
timestamp: August 28, 2016, 07:18:09 pm
content: Delete Delete Delete

author: grifftech
author_rank: Frequent Contributor
timestamp: August 28, 2016, 07:21:49 pm
content: Where is the image?

author: Ian.M
author_rank: Super Contributor
timestamp: August 28, 2016, 07:38:09 pm
content: Chances are the 'ghetto diode' is too slow for the application. What's its part number?ATX PSU diodes wont be any use if the rail the diode is for is over about 18V. They wont have the voltage rating.The original SR210 is probably this 2A 100V Schottky diode:https://www.wontop.com/uploadfiles/56/sort_excel/pdf/sr22.pdfbut we'd need exact dimensions to confirm that.

author: Ian.M
author_rank: Super Contributor
timestamp: August 28, 2016, 07:53:05 pm
content: Yes. The 10A10 is a normal silicon PN junction power diode intended for 50/60Hz rectification. You need a Schottky diode (or possibly an ultra fast 'normal' diode) for a switched mode boost circuit like that.Try the FR202 - it's got the voltage and current rating you need and *MAY* be fast enough. If it runs hot you'll probably need to buy a 100V 2A Schottky diode though if you've got some scrap boards from large screen CRT TVs or monitors, you may get lucky and find something suitable near the line output transformer or in the PSU.

author: Ian.M
author_rank: Super Contributor
timestamp: August 28, 2016, 08:03:24 pm
content: I've edited above. Try FR202.As to what the 10A10 diode is good for - well if you are building a HV DC motor drive or a real brute of a valve power amp with a linear PSU, it would be a good choice for use in the bridge rectifier feeding the high voltage bus.

author: Ian.M
author_rank: Super Contributor
timestamp: August 28, 2016, 08:36:48 pm
content: In that case you are S.O.L. The switching frequency must be too high for anything other than a Schottky.

author: Ian.M
author_rank: Super Contributor
timestamp: August 28, 2016, 08:50:48 pm
content: No. To get 34V for the backlight, the diode has to stand that + the inductor ringing when the current through the diode cuts off which can take its anode negative by the same amount, so it can have 70V across it. Add a moderate safety margin and you are up to 100V.A motherboard Schottky certainly wont have a 100V rating as the max voltage used for any rail is 12V. Ratings may be as low as 20V.

author: Ian.M
author_rank: Super Contributor
timestamp: August 28, 2016, 09:38:28 pm
content: Its just a best guess as there are a few other (much smaller) inductors on the board. However the 34V backlight rail is a good match to the diode's 100V PIV rating. If that voltage's gone AWOL and the other rails are OK, its conclusive evidence for it to be in the backlight boost circuit. Other rails aren't likely to be >12V and any diodes in switching buck regulator circuits running off 12V don't need more than a 30V PIV rating.
Help: CNY70 photo sensor as a binary switch - Page 1
Forum section: electronics / beginners

author: jbs
author_rank: Contributor
timestamp: May 17, 2020, 09:55:08 pm
content: Hi,I'm trying to use a CNY70 as a binary switch. I have it connected to a LM339N comparator. The reference voltage (negative input) is given by a potentiometer. The output of the comparator is connected to an Arduino UNO.What I want is for the CNY70 to give out HIGH whenever its output voltage surpasses the threshold reference voltage set by the potentiometer, and LOW whenever it goes below.However the output fluctuates too much. At the threshold I get crazy readings on the Arduino of 0's and 1's before it settles.How can I avoid this?Thanks,Joël

author: StillTrying
author_rank: Super Contributor
timestamp: May 17, 2020, 11:31:47 pm
content: You'll have to add a diagram of how the CNY70 and LM339N are connected including the supply voltages.

author: Doctorandus_P
author_rank: Super Contributor
timestamp: May 17, 2020, 11:56:53 pm
content: Use a schmitt trigger.It's probably as simple as a resistor between the output of the LM339 and it's non-inverting input.https://nl.wikipedia.org/wiki/Schmitt-triggerOr, better: do it in software.contact bounce is very common for mechanical switches, and usually it's taken care of by reading the input at regular intervals (for example between 1 to 10ms) and only accept an input change when multiple consecutive logic levels have the same value."State" is a uint8_t counter variable.SWITCH_HIGH and SWITCH_LOW are defined constants. when "State" becomes equal to one of these, then the state of the switch has changed.Code:void TThreadSwitch::Debounce( void) {// Debounce for the switch.if( SWITCH_PIN & SWITCH_BIT) {if( State < SWITCH_HIGH) {++State;}}else {if( State > SWITCH_LOW) {--State;}}}

author: jbs
author_rank: Contributor
timestamp: May 18, 2020, 09:17:10 pm
content: This is extremely helpful, Doctorandus. Both of your ideas.Joël
Help, Component identification SOIC8  - Page 1
Forum section: electronics / beginners

author: RoadRunner
author_rank: Frequent Contributor
timestamp: November 14, 2020, 09:32:38 am
content: I have recently ordered MB510PF from china , but instead got a somewhat small SOIC8 IC with similar markings. Before i throw them in garbage i was wondering if any one recognize this.marking5109243M19I have filed it and verified there is some silicon in there, its not like completely dummy. I can not verify any marking on the silicon itself as i do not have good enough microscope.Regards

author: Mechatrommer
author_rank: Super Contributor
timestamp: November 14, 2020, 09:56:47 am
content: what do you expect? probably thats what you ordered...https://www.datasheets360.com/pdf/-2410128865441133324or else, probably...https://www.vishay.com/docs/70788/si9243.pdf

author: Jwillis
author_rank: Super Contributor
timestamp: November 14, 2020, 12:18:38 pm
content: Before you throw them out , why don't you verify that they work or not . Taking microscopic photos won't do any good unless you have something to compare it to. Besides not all silicon chips are marked. Even from the " legitimate" manufacturers.

author: amyk
author_rank: Super Contributor
timestamp: November 14, 2020, 10:28:08 pm
content: Yes, that looks like either NOS or used, and also what a real one should look like. You haven't said anything about whether they actually work or not.

author: RoadRunner
author_rank: Frequent Contributor
timestamp: November 14, 2020, 10:38:08 pm
content: I am not worried about receiving wrong part, I guess i agreed to inherent risk when ordering from China.Image shown in above is the of particular Chip which i tried to solder and verify if work. But it does not work.I just wanted confirm if this particular part which i receive has any use what so ever.
Help converting 0-12v PWM to 0-5v ttl - Page 1
Forum section: electronics / beginners

author: shiftline
author_rank: Contributor
timestamp: August 12, 2017, 10:29:10 pm
content: What is the best way to convert the 0-12v PWM fan signal to 0-5v TTL for the laser driver Would a 5v regulator work or should I try a few resistors?Sent from my iPhone using Tapatalk

author: Kjelt
author_rank: Super Contributor
timestamp: August 12, 2017, 10:41:47 pm
content: What is the frequency? I would use two resistors followed by a fast active ttl gate or a schotkey diode with an active gate with 5V pull up resistor on the input such that the 0v of the 12V pwm will create a 0,3V (schotkey forward voltage drop) on the active gate while a 12V will do nothing and the gate gets 5V from the pull up resistor.Google level shift

author: shiftline
author_rank: Contributor
timestamp: August 12, 2017, 10:52:35 pm
content: I'll look it up when I get home! ThanksThe 12v is the fan pwm controller from the 3d printer. The laser stats say 9khz for the frequencySpecification parameter:Body size: long 50mm* wide 50mm* high 100mmOutput wavelength: 450nmOutput power: 2.5WModulation frequency: TTL can be modulated ,0v- off 5V open ,PWM frequency <9KhzWorking voltage: DC=12VWorking current: I<2AFocal length: adjustableOperating temperature: 15 degrees to 45 degrees CIt's "working" straight off the 12v signal but the laser won't 100% turn off which is leaving traces from movementSent from my iPhone using Tapatalk

author: shiftline
author_rank: Contributor
timestamp: August 13, 2017, 08:32:19 am
content: I ended up using a voltage regulator and 2 mosfets to get it goingSent from my iPhone using Tapatalk

author: nxym
author_rank: Newbie
timestamp: December 14, 2017, 12:21:31 am
content: I have the same problem too .I must connect ttl to a 12v pmw fan output so my laser goes on and off. My Laser is 12v 5A 5W so it needs external power supply to feed current.I manage to control on/off with an arduino when sending 5v on the ttl input and their external power supply. Now i need to translate the 0v/12v of the fan to 0v/5v so i can use it on my 3d printer.Can you tell me how do you manage to convert the 12v signal?

author: danadak
author_rank: Super Contributor
timestamp: December 14, 2017, 01:23:21 am
content: You could feed a 0 - 12V signal thru a series R straight intoa 5V CMOS input. This relies on internal protection diodeto clamp the swing <= Vdd + Vdiode (.7V). You limit the currentto datasheet spec for injection current of input to prevent latchup.Or if PWM has an open drain/collector output just tie an R to5V Vdd from open drain/collector output and tie junction atoutput to 5V part input.Or use a MOSFET, gate to 12V output, source to ground, drainto R to 5V Vdd and drain to 5V input. If Bipolar add series R inbase to 12V output to limit base current.All these techniques alter the duty cycle a bit, but depending onapplication may not be of concern.Regards, Dana.
HELP CREATING AUTORANGING MULTIMETER WITH uC - Page 1
Forum section: electronics / beginners

author: jfiliaul
author_rank: Newbie
timestamp: July 04, 2011, 08:56:22 pm
content: Ok, thanks for check out my question.... I want to make a multimeter using a microcontroller and a 12 or 16 bit ADC. So far all I have been able to do is use a voltage divider (2 resistors duh) and measure 0-20vDC by dividing the voltage in question by 4 and it was spot on however when i tried to create one that divided by 20 so I could measure up to 100vDC the smaller voltages were off by 2 volts or more. I assume what i need to do is somehow choose the correct voltage divider based on the voltage we want to measure but I dont want to have a selector switch I would like to make the circuit autoranging. Any simple schematics available? Can anyone help me?
Help deciphering a variable (or maybe a constant) on a datasheet - Page 1
Forum section: electronics / beginners

author: wydra91
author_rank: Newbie
timestamp: December 29, 2020, 07:03:29 am
content: Hey everyone!I've been a longtime watcher of EEVBlog and I've finally gotten off of my butt and started getting back into hobby electronics.I just recently got an o-scope and have been playing around with decoding IR signals. I'm bread-boarding out a very simple circuit to hook my o-scope to, in order to reliably read IR pulses when I need to. While I was working on it, I got a bit lost in thedatasheet for the TSOP38238 IR Receiver. Down in the test area, it mentions that $$T_{pi}\ge10/f_0$$ for optimal operation, but I have no idea what f0actually is! I know this is more for if you're designing pulses to send to the receiver, so it doesn't have much to do with decoding, but I'm trying to teach myself to fish here.Also, out of curiosity, is there a place/method that I can use to reference what these notations typically mean? I managed to find references elsewhere in the sheet to most variables, but this one is stumping me!Thanks for the help!EDIT: Also just as a heads up, I know that the TSOP38238 works just fine with a 2.8v power-supply connected straight in, I was just dinking around with the (i think) decoupling cap and inline resistor on power.

author: pigrew
author_rank: Frequent Contributor
timestamp: December 29, 2020, 07:15:23 am
content: For this product, they sell different variants with different f0 (the carrier frequency). The model numbers are shown on the first page of the datasheet.The TSOP38238 operates with a 38 kHz carrier.EDIT: Or maybe I'm getting the terminology wrong... It's a 315 THz carrier, with 38 kHz OOK modulation? That still sounds wrong.

author: wydra91
author_rank: Newbie
timestamp: December 29, 2020, 07:44:42 am
content: Quote from: pigrew on December 29, 2020, 07:15:23 amOHHHH! It's the carrier frequency! I get it now! I just watched Dave's video on IR Protocols and I remember that being important to differentiate from ambient noise in the sensor environment. So they're saying the input pulse (I assume that's what Tpiis) needs to be more than .26 ms for the sensor to reliably read a pulse and go low, if I'm reading that correctly.
Help decoding a signal captured with an LA1010 Logic Analyzer - Page 1
Forum section: electronics / beginners

author: Jaxaay
author_rank: Newbie
timestamp: March 18, 2025, 10:52:09 pm
content: Hello everyone,I need help decoding a signal I captured using an LA1010 Logic Analyzer. Here’s the situation:I’m working on a project where I want to insert an electronic module between the module that contains the switch button and the vehicle’s ECU. The button toggles between gas and gasoline modes, and the goal is to automatically switch modes every 15 minutes without manually pressing the button.The module containing the button also displays the remaining gas in the tank and indicates the current energy source (gas or gasoline) through LEDs.I connected the LA1010 Logic Analyzer to the communication line between the module containing the button and the vehicle’s ECU. I captured three signals:With a button press to switch from gasoline to gas.With a button press to switch from gas to gasoline.Without any button press.I’ve attached the three captured files in .kvdat (remove the ".doc" to open it with KingstVIS, the forum doesn't allow ".kvdat") format.Could someone help me decode the communication protocol and understand the data format? Any guidance or advice on how to properly interpret the captured data would be greatly appreciated.Thanks in advance for your help!
help decoding Shcottky diode datasheet - Page 1
Forum section: electronics / beginners

author: anishkgt
author_rank: Frequent Contributor
timestamp: February 21, 2018, 03:13:00 pm
content: Hi,I am trying to figure out the voltage drop for this application where i need to detect the OFF state of an AC load,here a MOT. But this diode is not in the cricuit as a rectifier for the MOTThe power to the schottky comes when the MOT is switched OFF where a small current is detected when the secondary is open.My question, what would be the voltage drop of this diode (http://www.smc-diodes.com/propdf/SUR1060%20N0414%20REV.A.pdf) i understand it as. @10A the voltage drop would be 1.18v. For my application when the secondary are shorted there is voltage difference from .5vac and i would just need to read it from the ouput of the above circuit that goes into an arduino. The only load connected are those caps and Resistors.

author: anishkgt
author_rank: Frequent Contributor
timestamp: February 21, 2018, 03:25:13 pm
content: attaching schematic

author: ogden
author_rank: Super Contributor
timestamp: February 21, 2018, 09:02:46 pm
content: Quote from: anishkgt on February 21, 2018, 03:13:00 pmFig 1 is answer to your question: at 30A forward voltage will be around 1.5V, at 1A it is 0.8V average. Main question is - why use so powerful 10A diode here?

author: anishkgt
author_rank: Frequent Contributor
timestamp: February 21, 2018, 09:21:49 pm
content: Fig 1 ?My idea is to switch ON the MOT by detecting the voltage change at the primary when the Secondary are shorted. I can see a voltage drop of .5VAC when shorted. How can i monitor this voltage change with an Arduino. To the best of my knowledge i could think of a schottky diode that would help me here or is there a better approach to this that would not drop very much if not any voltage. A precision rectifier using an opamp like the LT1078 would be another option but i lack the knowledge to choose the slew rate and Gain Bandwidth.
Help decoding transformer pinouts - Page 1
Forum section: electronics / beginners

author: BradN
author_rank: Newbie
timestamp: September 02, 2024, 08:54:24 pm
content: I was attempting to dejunk my collection of junk and came across this transformer. I am not sure how to decode the pin legend printed on the face. I would appreciate any help with this.

author: Xena E
author_rank: Frequent Contributor
timestamp: September 02, 2024, 09:35:31 pm
content: Simply.Numbers in the circles are the terminals looking directly at that face.The numbers listed on the left are the terminals, shown winding start to finish.Numbers on the right are the voltages that correspond to the associated terminals.Seems to be an HF transformer of some type it stating 1500c/sRegards,X

author: BradN
author_rank: Newbie
timestamp: September 03, 2024, 01:03:16 am
content: on pins 12-26-5 produce 19-0-19 but which pins are the primary terminals to produce that voltage.

author: ledtester
author_rank: Super Contributor
timestamp: September 03, 2024, 04:55:56 am
content: I think you would use one of 115V windings (or parallel them for more power) or connect the two 115V windings in series if you have 230V power.You have to be mindful of the phasing.Actually, upon closer inspection I'm not sure you can connect the two 115V windings in parallel as they might already be in series. Check to see if 29 and 11 are connected. In fact, it would be a good to check the resistance between all of the pins to see if any of the windings are connected.

author: Xena E
author_rank: Frequent Contributor
timestamp: September 03, 2024, 05:19:19 am
content: Beware the 1500c/s legend.If it's a specialist device it won't like being plugged into a wall outlet!I've seen 400Hz ones before, for aircraft use, but 1500 is odd.Bung it on Ebay, someone is looking for one!Regards,X

author: inse
author_rank: Super Contributor
timestamp: September 03, 2024, 05:54:50 am
content: I also don’t think it’s useable at mains voltage, maybe it has been part of an ancient inverter.The high voltages and the 6.3V aim at something with tubes, maybe a transmitter
Help define a trigger to capture when a 240V ac supply is switched off - Page 1
Forum section: electronics / beginners

author: hazzer
author_rank: Regular Contributor
timestamp: September 12, 2025, 01:12:11 pm
content: I'm comparing RC scrubber circuits on a 240V AC contractor, and while I can initially trigger on the back EMF pulse once I have the snubbed in cct and close to the correct value there's no longer a big enough pulse to trigger from....QuestionCan anyone think if I can setup the MSO (a HMO 1202) to trigger when the AC voltage is switched off......using only the settings within the HMO 1202...I initially though I could define a math formula but the HMO doesn't support triggering from a math trace...Just now I'm looking at the pass/fail setup but I haven't managed to grab a trace to show the point where the contractor is switchedI'm trying to avoid setting up up an external trigger as I'm using a differential probe and I'd like to keep it as the only connection to the mains....... any thoughts appreciated.... am I'm over thinking this.... is there a simple solution?HPS I'm hopeful the PASS/FAIL menu will provide a solution...

author: ahsrabrifat
author_rank: Regular Contributor
timestamp: September 13, 2025, 05:08:26 pm
content: If your scope supports “pulse missing” or “pulse width” you can trigger when a mains half-cycle is missing. Not all HMO models have that, but worth checking the trigger menu.

author: Aldo22
author_rank: Super Contributor
timestamp: September 14, 2025, 08:54:38 am
content: I don't know your model, but my cheap scope has an “overtime” trigger.Are you're looking for something like this?

author: MathWizard
author_rank: Super Contributor
timestamp: September 15, 2025, 10:35:04 am
content: Oh scope triggering on a missing signal, I thought you meant a circuit to turn on when the AC power is gone, so I was thinking of some RC circuit that allows a PNP to turn on once AC is gone for long enough.I wonder if my scopes can do that, interesting.So I'm not sure about digital or analog triggering anyways, I guess both types add some auto-triggering just so you can display a trace on screen (not for single trigger).But yeah if your scope does not trigger on when the next signal period would be, then what happens anyways, ? Does it just start triggering at preset intervals to keep drawing a trace?

author: Aldo22
author_rank: Super Contributor
timestamp: September 15, 2025, 11:34:34 am
content: Quote from: MathWizard on September 15, 2025, 10:35:04 amThere are two options for my scope. The manual states:Quote from: Hantek DSO2000 manual

author: MathWizard
author_rank: Super Contributor
timestamp: September 15, 2025, 01:40:33 pm
content: Ok well that's those things I've forgotten, and I'm used to my modern DSO's and auto-trigger is usually on. I'll have to try normal sometimes then.I read about sequence triggering, but I've not really tried it yet. I'm curious to see if I can record some long and sparse digital signals that eluded me before.