hybridfree/eevblog-posts huggingface dataset:
Electronics-DIY Kit Question (strange behavior) - Page 1
Forum section: electronics / beginners

author: outofstepper
author_rank: Contributor
timestamp: August 29, 2012, 09:10:40 pm
content: Strange for me.Picked up the Electronics-DIY kits for their signal generator and frequency counter:http://www.electronics-diy.com/function-generator-kit-xr2206.phphttp://electronics-diy.com/store.php?sel=kits&sub=50mhz_frequency_meterI'm powering both from the same (import) power supply @ ~12VThe signal generator leaves a lot to be desired. Thats a different topic, though.The counter seems to work well and appears accurate (at least as well as my scope readout).However, I noticed my waveform change when the output of the generator was attachedto the input of the counter.I attached my 2nd channel probe to the powersupply to see if it was dipping.. as soon as Imake the connection, the signal from the generator disappears. Drops to zero.Power supply seems to be as stable as always.Removing CH2 probe gets my signal back.Any thoughts on what I might be doing wrong?Thanks.

author: w2aew
author_rank: Super Contributor
timestamp: August 29, 2012, 10:04:27 pm
content: Well, the signal generator output is changing when you connect the counter because the input circuit of the counter is a pretty lousy design. It's just AC coupled into a grounded common emitter amplifier. Thus, large signals will be subject to varying load impedance when the transistor turns on and off, and goes in and out of saturation - which will clip and distort your signal shape. As for the signal going away when you connect your scope probe - sounds like something is amiss between your circuit's ground and the scope probe's ground.

author: outofstepper
author_rank: Contributor
timestamp: August 30, 2012, 04:44:28 pm
content: Thanks for the quick reply.Re: ground problem? I almost never (read: never) connect to the P/S earth terminal.Ie floating ground. Maybe I should try reinstalling the jumper clip between earth groundand negative terminal.Thanks again.
Electronics Foundations & Basic Circuits Online Course - Page 1
Forum section: electronics / beginners

author: Electro Fan
author_rank: Super Contributor
timestamp: November 01, 2017, 01:31:46 am
content: https://www.linkedin.com/learning/electronics-foundations-basic-circuits/welcomeThis is from LinkedIn not MIT, but it looks like a good course for beginners trying to get a lay of the land. Very nice video quality and good introductions to basic topics and concepts. The course is segmented into digestible chapters, includes some test questions, and has transcripts. Plus it appears to be free. Pretty simple & basic but very nicely presented. If you are looking for introductions or high level explanations regarding the subjects presented you might enjoy this.
Electronics group in Sydney (Australia)?  - Page 1
Forum section: electronics / beginners

author: Professor_Farnsworth
author_rank: Newbie
timestamp: December 04, 2018, 01:03:21 pm
content: Hi AllI'm interested in getting into electronics as a hobby, and would love to learn as part of a group versus just using internet solo. I'd appreciate it if someone could point me in the right direction to a groupThanks
Electronics Nerds in Turkey and feedback about my work - Page 1
Forum section: electronics / beginners

author: alienozi
author_rank: Newbie
timestamp: January 27, 2019, 10:24:57 pm
content: Greetings Nerds!I am a newbie from Turkey, Izmir. I am currently a 12th-grade student in Bahcesehir Sci. Tech. High School. This year I will take an exam in order to choose a university. I am going to pursue a career as an EE. I have been interested in electronics since I was 12. I also have some knowledge that is comparable to a first-year undergrad. I still lack much knowledge and I appreciate and guidance that you may provide.However, in Turkey, I know nobody that likes electronics. I am wondering what anybody here is from Turkey? I would love to share ideas and talk about electronics.Moreover, I have some circuits of mine and projects. I would love to hear some feedback about my work. How can I improve my circuits and schematics? I have a website of mine that I would like you to take a look at. Any feedback is appreciated and pleasedo not go easy on me!https://alienozioa.wixsite.com/electronicsis my web-page.PS: I am a huge Dave fan also!
Electronics parts discount/wholesales company list? - Page 1
Forum section: electronics / beginners

author: alank2
author_rank: Super Contributor
timestamp: April 24, 2015, 05:52:10 pm
content: Hi Everyone,Is there a list of places that sell discounted or wholesale electronics parts?I know about these:http://www.bgmicro.com/http://www.allelectronics.com/http://www.goldmine-elec-products.com/I'm trying to find a reasonable price on some 40x2 lcd displays with backlight. I had a whole bunch of them for about $3 each, but I ran out. I think they were the powertip brand.

author: Richard Crowley
author_rank: Super Contributor
timestamp: April 24, 2015, 06:19:57 pm
content: In my 2nd and 3rd tier there are:http://www.mpja.com/http://www.apexjr.com/http://www.alltronics.com/http://www.surplussales.com/http://www.parts-express.com/http://www.herbach.com/http://www.fairradio.com/Although more of those kinds of things are now perpetually available on Ebay.I am even finding more stuff on Amazon (believe it or not). For example:http://www.amazon.com/gp/product/B00S4EWF6G/ref=oh_aui_detailpage_o04_s00?ie=UTF8&psc=1Better availability and delivery than from Adafruit at 1/2 the price! Sorry Limor.

author: Simon
author_rank: Unknown
timestamp: April 24, 2015, 06:50:45 pm
content: I don't know how anyone survives on amazon, they offered to give me an account but the fees were too high so I told them to stuff it.

author: slburris
author_rank: Frequent Contributor
timestamp: April 24, 2015, 08:55:32 pm
content: Here's one I've never seen mentioned:http://www.excesssolutions.comI've only been there in person, not shopped on their web site.Scott

author: KerryW
author_rank: Regular Contributor
timestamp: April 24, 2015, 10:39:56 pm
content: Some I've had good luck with:Futurlechttp://www.futurlec.com/index.shtmlDeal ExtremeNo minimum order, free shippingDipMicrohttps://www.dipmicro.com/store/

author: casinada
author_rank: Frequent Contributor
timestamp: April 25, 2015, 05:40:29 am
content: http://www.taydaelectronics.com/
Electronics perspective of Verification and Validation - Page 1
Forum section: electronics / beginners

author: crazy horse
author_rank: Contributor
timestamp: March 28, 2016, 10:44:21 pm
content: Want to know for job interview purposes.A lot of the info on V&V seems to be more focused on software and closest stuff for electronics is FPGA and ASIC stuff.I see the definitions of:Are we building the product right = verificationAre we building the right product = validationI have worked as electronics design engineer for 15 years, but it hasn't specifically been labelled this. The testing of the new designs is typically broken down to unit level testing and system testing.Say for example with an ADSL modem the unit level testing would involve lower level testing. Testing power supplies, testing filter performance, testing signal integrity, testing component temperatures, testing it meets required specifications like EMC, ITU specs etc. It then touches into a bit more system testing, but with a focus on the performance of the unit under test. This would be all under Verification.Then as a separate process the product would move onto system testing where it is tested that it functions in a system as expected. This seems like a bit of both Verification and Validation.Once it passes all this it would move onto customer acceptance testing. This is what I take to mean validation testing.Is this a fair understanding of V&V from an electronics design point of view?
Electronics setup for wind turbine - Page 1
Forum section: electronics / beginners

author: fish654321789
author_rank: Newbie
timestamp: December 19, 2023, 05:08:16 am
content: Hello, I have a wind turbine project but I have a problem.I will use a 24v AC generator rated at around 5kw max output.I want to use the electricity in my home or put it back into the grid and for that i need 220/230v AC power.I can't find any 24v AC to 220/230v AC transformers.The current option I'm looking at is converting 24v AC to 24v DC and then convert 24v DC to 220/230v AC.The problem with this is that I firstly can't find any 24v AC to 24v DC converters and secondly this solution is presenting a lot of energy loss.What would your solution be?

author: Andy Chee
author_rank: Super Contributor
timestamp: December 19, 2023, 06:25:38 am
content: To put electricity back into the grid, you cannot use a simple AC transformer. This is because the frequency must be synchronised to the grid. Your wind turbine will definitely NOT be spinning at the right speed for synchronisation.This means you will need to use a DC-AC grid inverter in your installation, you will have to accept the energy losses.To convert 24V AC to 24V DC, use a bridge rectifier and filter capacitor (or even better, a battery).

author: Halcyon
author_rank: Unknown
timestamp: December 19, 2023, 06:30:36 am
content: Duplication of two other threads.
Electronics workshops at The National Museum of Computing - Page 1
Forum section: electronics / beginners

author: MosherIV
author_rank: Super Contributor
timestamp: June 23, 2019, 11:19:56 am
content: HiFor beginners (in the UK), the National Museum of Computing is starting some workshops on basic electronics and digital electronics.The workshop is lead by an experienced lecturer. The format is, presentations on subject matters then some practical experiment/build.You can sign up:Basic Electronics Workshop 17/18 Augusthttps://www.eventbrite.co.uk/e/basic-electronics-workshop-2-days-tickets-64041720510Digital Electronics Workshop x2 days – 24/25 Augusthttps://www.eventbrite.co.uk/e/digital-electronics-course-2-days-tickets-64042171860(For full disclosure, I volunteer at TNMOC. I have not been involved with the preperation of the workshop mentioned. I have met the volunteer presenting the worshop. I may be present at some of the workshops to help but do not count on it. I do not benefit financially in any way from the workshops.)Please no flaming or negative comments. We are trying to provide help to beginners with good intentions.
Electrostatics Question - Page 1
Forum section: electronics / beginners

author: Cujo
author_rank: Regular Contributor
timestamp: August 01, 2021, 05:22:52 am
content: I just started my electromagnetism class last week, and I'm having trouble of identifying this question to be either a Electric Field Charge Distribution or a Gauss's Law question?"Calculate the electric field at the surface of an infinite plane having a surface charge density of 103 C/m^2"

author: CatalinaWOW
author_rank: Super Contributor
timestamp: August 01, 2021, 05:45:13 am
content: Whichever way you think of it you must recognize the simplification that "infinite plane" makes. The field is nice an uniform, perpendicular to the plane and identical in every square meter. So you can just solve the problem in one square and with the knowledge that no effects from that square extend out of the rectangular tube extending perpendicular to that square.

author: ejeffrey
author_rank: Super Contributor
timestamp: August 01, 2021, 05:51:00 am
content: That is a classic Gauss's law question with one clarification: you can't find the field at the surface itself which is undefined in this instance. You can only find the electric field on either side of the charged surface.The first thing to do is to use symmetry to realize that there can be no transverse component of the field, the only field is normal to the charged surface.Then construct a Gauss's law surface such as a cylinder such that every surface is either parallel to the electric field or perpendicular. The total flux through the perpendicular faces has to equal the charge inside. Don't forget to count the flux through the faces on both sides of the charged plane.
Electrotherapy Equipment - Page 1
Forum section: electronics / beginners

author: GrahamWhitson
author_rank: Newbie
timestamp: June 20, 2020, 09:47:33 pm
content: Hi Guys.Thanks for letting me in. Hopefully i dont waste anyones time with dumb questions and if i do, I apologise in advance.My better half is a Vet Physio and she uses electro therapies on her patients. Ie PEMT, lasers etc etc. Sometimes she has an issue with what is already available on the market. So ive decided to look into making a more bespoke product for her patients. Hence a more effective treatment.From what I can figure the "mats" if you will, basically are toroidal inductors (I think) sewn into them.The machine that powers them has a base frequency, adjustable between 50 and 200 hZ with a pulsed frequency of 17.5 hZ to constant.I have an understanding of electrics but electronics take me a lot more time to understand.Im terrible at explaining things but i hope someone can ungarble that and tell me if i can either buy or make these magnets so i can make the products more patient specific.Thanks for your time guys

author: AVGresponding
author_rank: Super Contributor
timestamp: June 21, 2020, 08:00:22 am
content: As is so often the case, a picture (or two) is worth a thousand words.

author: Ian.M
author_rank: Super Contributor
timestamp: June 21, 2020, 09:00:26 am
content: X-ray a mat to find out what's in it!Then you'll need a medical grade isolation transformer (because its regarded as bad form to electrocute the patient), a DSO to check what waveform the commercial unit is driving the mat with, and an AWG and a power amp to generate your own drive signals.If you want to design your own mats. you'd need to either have a thorough understanding of PEMT in therory and practice, or dissect one to discover exactly how its constructed. As it needs to be sealed and sterilisable, you are likely to have problems reproducing it unless you've got a moulding machine that can handle large areas of medical grade silicone.
Elektor Curve Tracer Sanity Check - Page 1
Forum section: electronics / beginners

author: Zielsziek
author_rank: Contributor
timestamp: July 06, 2025, 03:03:13 pm
content: Hello,I have built the following curve tracer and have two questions about it:1. I drew up two PCBs and I am inclining to go with the SMD version as it is smaller. I have not added the copper pour yet. Do you think the layout is ok? I made sure to have decoupling as per datasheet and the decoupling caps are fairly close to the IC. I know they are not perfect but I want to make sure that I got the rough idea.2. I noticed that when the leads are open the line is 45 degrees on the scope screen. I am assuming this is due to the disastrous idea of building such a device on a breadboard. The reasoning behind this is due to the fact that I wanted to make sure that I will not encounter oscillation. I wanted to use an LM1875 at first but it simply kept oscillating. The TDA2030 worked fine. I also wanted to make sure that I would not have trouble with the AGC done by the JFET which was a BF245A in the original design. I used MMBFJ202.Thank you. Looking forward to any tips!

author: Terry Bites
author_rank: Super Contributor
timestamp: July 08, 2025, 12:39:46 pm
content: No schematic??A 45' slope indicates a pure resistance.I imagine there won't be and high frequency action. A few kHz at most.Its unlikely that a lot of layout will not be that crucial.Most layout care is needed around the power drivers and psu as you've found.Check thermal management on driver ics and power resistors. Heatsinks?My advice is to pour the top layer with hot bits the and place the small components and the main routing on the bottom layers.Put hot resistors on the top and maximise their tie widths in the thermal breaks.Small signal jfets are pretty interchangeable. They often only differ in terms of gain-bandwidth product.The LM1875 datasheet shows suitable PCB layouts.

author: jwet
author_rank: Frequent Contributor
timestamp: July 11, 2025, 03:31:32 pm
content: A big improvement you could make to this design is to use PC mounted rotary switches and pots edge mounted to the board. With the current design, you'll end up with a big ball of wires going to switches and pots picking up noise, etc. Its would also be much harder to build and you'll be cursing broken wires. Arrange all the controls on one side of the board in some nice arrangement for use. Include LED's, etc. You might want to choose an enclosure beforehand and let this constrain your design. PCB's are as much about mechanical and ease of manufacture as they are electrical.Good luck.

author: UnijunctionTransistor
author_rank: Frequent Contributor
timestamp: July 11, 2025, 03:51:30 pm
content: I also second JWET’s recommendation of choosing a proper enclosure first, arranging the transformer and bulky components inside, and only then laying out your board.I also recommend that you post the schematic.
Elektronika 7K, Display Dimming - Page 1
Forum section: electronics / beginners

author: RobNorthen
author_rank: Contributor
timestamp: May 31, 2020, 08:10:41 am
content: I'am waiting for an Elektronika 7K clock to arrive. It is the big brother of the Elektronika 7M. The smaller 7M got a dimmer switch, but the large 7K does not. I would like to add one. The logic boards seems very much alike. I have attached the schematics for both.Have tried reading the 7M schematic to see how the dimming is done, but have big troubles undertand and follow it (Russian). I think switch "SA4" is the dimming that runs to "xs1" cable loom, goes to to pin 10 on IC "D4". It also seems like the other side of the switch goes to a transformer tap.It just seems very strange to switch AC voltage into an IC, so I'am pretty sure I missed something.Was also thinking about just adding a big power resistor in series with the filaments power, but not sure its the right way to go. I would guess the 7M clock is messing with grid or segment voltage, to dim the display.Would be happy if someone could help.https://www.glaver.org/blog/e7-06-schem-web.pdf- Elekronika 7Khttps://www.glaver.org/blog/elektronika-schematic.pdf- Elektronika 7M

author: Canis Dirus Leidy
author_rank: Regular Contributor
timestamp: June 01, 2020, 11:50:51 pm
content: Quote from: RobNorthen on May 31, 2020, 08:10:41 amNot really. SA4 connect negative pole of VD1 rectifier with common wire of the filament circuit.Quote from: RobNorthen on May 31, 2020, 08:10:41 amAs I understand it, there is a tricky method of the anode voltage control: instead of directly changing the anode voltage, a negative bias is added at the cathode side.P.S. As for 7-06K, the simplest method here is to add PWM-controller to the "+25V" (anode voltage) circuit.

author: RobNorthen
author_rank: Contributor
timestamp: June 02, 2020, 10:30:56 am
content: Thank you Canis, it makes good sense with the +25v, I will do that.

author: RobNorthen
author_rank: Contributor
timestamp: June 04, 2020, 09:55:50 am
content: The point of this is, of course to dimm the light, but I was also hoping this would give the tubes a longer life ?I will be replacing all the tubes with NOS ones.
Elektrosluch 3 - Export accurate BoM from schematic .BRD - Page 1
Forum section: electronics / beginners

author: dan-esc
author_rank: Newbie
timestamp: October 26, 2020, 04:15:29 am
content: Hi all,I would like to make an Elektrosluch-3 however the creator has not made a BoM and has suggested I use the schematic.I opened the the .BRD file and exported the BoM through Autodesk Eagle however it's not very accurate and therefore I'm not sure of which parts to source online.I've tried Digikey and Mouser however uploading the rough BoM is missing perhaps too much information. And since I don't have the theory-based knowledge I'm not sure how to find the right parts.https://github.com/LOM-instruments/Elektrosluch-3/tree/master/hardwareAny help or creation of the BoM would be really appreciated by me and I'm sure others, thank you
Elenco AM/FM-108CK--FM Alignment Procedure - Page 1
Forum section: electronics / beginners

author: wsscott
author_rank: Newbie
timestamp: January 09, 2024, 08:43:53 pm
content: I built this kit a few weeks ago and it works ok. I was able to align the AM pretty easily, first manually and then using a scope and a RF Signal Generator.My main problem is with the Alignment procedures for the FM section. It's built and I am receiving stations, but I went through the alignment procedure, and I'm not getting any signals on the scope and the procedure for manual alignment doesn't seem to make any sense.For example: It tells you to adjust T1, T2 and T3 for the minimum voltage and reduce the Volume if necessary. Well the voltages only change from maybe 7 volts to 6.9 volts, and if the voltage is less the Volume is going down, not up. The Volume does go up if you increase the T's voltage. By lowering the voltage you lower the volume.I really couldn't get any noticeable changes in T4 and T5.Then the procedure for oscillator alignment seems off. It says using the magic wand brass end if the station is heard then L3 needs less inductance and so pull apart L3 until the station is heard. Well if you're hearing the station why pull apart the LC "until the station is heard"? Same conflict using the iron end of the wand.I don't know. These instructions just don't make any sense to me.Also, the connection of the signal generator to the T14 insertion point doesn't get me any signal on my scope. I don't know if my scope or its probe are not sensitive enough, or maybe the probe is not sensitive enough.So I'm pretty confused and frustrated. I'm getting FM stations, but I'd like to get the radio setup properly.Thanks for listening to my rant!Any help would be appreciated.
Elenco AM/FM-Separate Power Amp module - Page 1
Forum section: electronics / beginners

author: wsscott
author_rank: Newbie
timestamp: January 03, 2024, 08:37:44 pm
content: I built this kit, and its working fine, but I find using the separate power amp board a bit awkward, so I use the IC instead.But I was wondering, what can I do with that board? Can I use it in some other project or as an amp for some other kind of circuit?Any ideas?Thanks.
Elenco XP-720 in Australia - Page 1
Forum section: electronics / beginners

author: shogun88
author_rank: Newbie
timestamp: July 26, 2015, 11:27:15 pm
content: Hi EveryoneApologies if this has been asked previously. I have search through the forum but have still yet to find an answer to this question.Is the Elenco XP-720 Kithttp://www.amazon.com/Elenco-Triple-Output-Power-Supply/dp/B0002DT0GUcompatible with 240V AC Input?And alsoCan anyone else recommend a Variable DC power supply kit for use in Australia? Around $100 AUD mark?Thank you

author: GreyWoolfe
author_rank: Unknown
timestamp: July 26, 2015, 11:46:06 pm
content: I have built the kit and as far as I know, it is only 120V so you would need a step down transformer to plug it into.

author: shogun88
author_rank: Newbie
timestamp: July 27, 2015, 01:43:14 am
content: Cheers thanks for the info. I'll just have to keep looking around.
Elenco XP-720 PSU Clone - Page 1
Forum section: electronics / beginners

author: HoracioDos
author_rank: Frequent Contributor
timestamp: March 03, 2017, 12:46:08 am
content: In the last months I've been playing with op-amps and a PSU with negative voltage would have been very useful. So it's time to build a simple linear PSU and leave the wall warts behind.I think I don't need something very fancy, so I decided to copy the Elenco XP720 (+-1.25V to 15V /1A and fixed 5V /3A outputs) with some changes.a) 220 VAC input.b) Additional fixed 3.3V with a LM1086c) Dual tracking without op-amps.d) 10 turns potentiometer to adjust voltage.e) Floating ground / earth switch.f) Digital voltmeter with rotary switch for output selection.g) Component replacement due to availability and costs. (BD438 instead of 2N6124 and 2N3906 instead of A70)h) Heatsink inside the case.i) Banana plugs in a triangle arrangement.Any advice would be most welcome! I attached Kicad schematic.
Elenco XP-720 Voltmeter - Page 1
Forum section: electronics / beginners

author: madcitygeek
author_rank: Newbie
timestamp: May 10, 2016, 12:47:51 am
content: Okay, I'm a noob and I built myself an XP-720 power supply. It works well, tests within reasonable ranges. I had a great time building it, my 6-year-old son helped.I'd like to add a pair of volt meters -- one for positive, one for negative. There seems to be ample room in the case -- I might be able to dremel out a couple holes.I was looking at these displays from Adafruit --https://www.adafruit.com/products/705-- the "Mini 3-wire Volt Meter (0 - 99.9VDC)" I figured I could solder them in between the outputs of the LM317, wiring the "red, power" wire to the 5v output from the 7805.Am I wrong? Is there a better way to add a meter?

author: Dragonfly
author_rank: Contributor
timestamp: May 10, 2016, 03:14:01 am
content: I don't see why that wouldn't work for the positive supply but you wouldn't be use this meter on the negative supply. It's range is 0-99.9VDC so it can't measure negative voltage.

author: rstofer
author_rank: Super Contributor
timestamp: May 10, 2016, 03:17:24 am
content: Duplicate response, see above!

author: madcitygeek
author_rank: Newbie
timestamp: May 10, 2016, 03:28:17 am
content: Good point. Could I wire it in backwards? That is, put two meters in and wire one to positive and one in backward for negative? Or use a switch to flip between them?

author: Dragonfly
author_rank: Contributor
timestamp: May 10, 2016, 04:02:39 am
content: That wouldn't work with this 3-wire meter because it expects the voltage between the red wire and the black wire to be a constant 5V. If you tried to wire the meter in reverse for the negative side (i.e., black to the negative output and white to ground) then the voltage between the black and red wire would vary with the voltage setting of your negative supply. An alternate approach would be to use the 2 wire version on the negative supply (https://www.adafruit.com/products/460) wired backwards. The downside is the 2 wire meter won't work when the negative supply is set between 0 and -3.2V. Anything beyond that should work though.
ELI5: Different potential power sources, common ground - Page 1
Forum section: electronics / beginners

author: stafil
author_rank: Regular Contributor
timestamp: May 31, 2020, 06:49:32 pm
content: I learned how to analyze circuits using KVL, KCL. but I am still having trouble with intuition when connecting more that one power sources that may have different potential.For example consider 2 scenarios for the simple circuit below.Let's assume in the first scenario the negative of V1 has 0 potential in regards to earth, while the negative of V2 has -5V potential in regards to earth. While in the second scenario they are both 0.How does it happen that they both solve the same?

author: TheHolyHorse
author_rank: Regular Contributor
timestamp: June 01, 2020, 04:42:02 am
content: The negative terminals of V1 and V2 are directly connected so they'll always be at the same potential.

author: Brumby
author_rank: Unknown
timestamp: June 01, 2020, 06:04:43 am
content: The scenario shown does not have any references to ground indicated which makes the question incomplete and/or ambiguous.If I were to guess at the question, the solution for an isolated circuit will be the same no matter what the voltage is with respect to earth, so long as there is only one connection to earth (ie - there is nocircuitpath you can trace back to a different point within the original circuit.)Except for electrostatic levels, voltages only count when they are part of acircuit(ie - circular topology)
ELMDuino not reading PIDs correctly - Page 1
Forum section: electronics / beginners

author: bborisov567
author_rank: Regular Contributor
timestamp: October 11, 2022, 03:20:54 pm
content: I am trying to read live data on my '01 clk200. ELM327 works correctly with the smartphone app. Also tested it through terminal and it works fine. I have it connected to Arduino uno and running the example sketch(it's on the github page of the library, linked below), just changing the respective functions. I tried intakeAirTemp() and i am getting 168, on rpm() i get 0 and when i try engineCoolantTemp() i get ELM_Timeout error, last picture is engineCoolantTemp() with debug turned on. Here is a link to the library github:https://github.com/PowerBroker2/ELMduino

author: mikerj
author_rank: Super Contributor
timestamp: October 11, 2022, 08:50:56 pm
content: Is the ELM actually connecting the the cars ECU? Have you tried checking the return value from myELM327.begin() to ensure it correctly initialised?

author: bborisov567
author_rank: Regular Contributor
timestamp: October 12, 2022, 06:14:39 pm
content: Quote from: mikerj on October 11, 2022, 08:50:56 pmBy default protocol is chosen automatically, so the elm should connect to the car.The last picutre is with the debug mode on /myELM327.begin(2000, true)/. I usually get ELM_TIMEOUT response when the elm has trouble connecting to the car.
EM87 "Magic eye" tube circuit questions - Page 1
Forum section: electronics / beginners

author: WimWalther
author_rank: Regular Contributor
timestamp: January 13, 2024, 02:30:06 am
content: Howdy friends,I've worked with quite a number of tube circuits over the years, but I've never much delved into the operation of the so-called 'magic eye' tubes. I'm planning to use one as a hole-filler on an amp conversion project - but on perusing a typical circuit I'm obviously missing the finer points. See the attached image.Based on the EM87 datasheet, G1 is operated between roughly 0V and -15V, denoting a fully open and closed 'eye', respectively. But G1 is tied to an 11:1 divider, connected to B+ 250V. This should place about 22V on G1, quite a ways from 0V.The signal source is an 8R speaker load driven by a 17-18W amp. This equates to 12V Rms, or about 16V peak. This isn't enough to even bring G1 to 0V starting point, much less the -15V for full closure.So how does this thing work? If you're thinking that the schottkey will pull G1 to near 0V, well ok, but then what's the divider for?

author: Roehrenonkel
author_rank: Frequent Contributor
timestamp: January 13, 2024, 01:35:52 pm
content: Hi WimWalther,loose the 10 Meg. I guess it's there to offset the display-range.Maybe you can breadboard it and see how the display is affectet with and without the "bias-resistor".Good luck

author: wasedadoc
author_rank: Super Contributor
timestamp: January 13, 2024, 01:50:43 pm
content: The diode effectively shorts the 1M resistor so the divider is more like 10M and 47k. For AC signal from the potentiometer, the diode and coupling capacitor are a dc restorer or clamp type circuit. The most positive tip of the AC after the capacitor cannot be more than one diode drop above zero volts. So all the signal is negative going from that small +ve voltage.

author: WimWalther
author_rank: Regular Contributor
timestamp: January 13, 2024, 05:02:25 pm
content: Quote from: Roehrenonkel on January 13, 2024, 01:35:52 pmBased on my experience with eye tubes in general, that 10M part must be fairly important. I say this, as it has appeared on every circuit I can recall having seen, going all the way back to 1930s radios that use the clasdic 6E5 round eye tube.ETA: Though I notice that it isn't shown in the image you posted.. wonder why?ETA2: Might be that showing the 10M is beyond the purpose & scope of the drawing, which is really just a basic symbolic idea from a datasheet.(That's not to say it isn't some kind of cargo cult electronics, but for now I assume it's there for a good reason =)
EMC compliance / ESD protection for proof-of-concept prototypes - Page 1
Forum section: electronics / beginners

author: Saimoun
author_rank: Frequent Contributor
timestamp: August 06, 2020, 08:16:42 am
content: HiLet us say I am making a proof-of-concept prototype, i.e. a prototype that will very probably be changed (a lot) before/if it goes into production.At this stage, is it necessary to start thinking and placing on the PCB components that will help EMC compliance?A precise example is I am planning on making a circuit which will use an isolated switching DC-DC converter from 24V to 3.3V. In the datasheet (https://www.cui.com/product/resource/pqp3-d.pdf) they mention an EMC compliance circuit:Would you recommend adding these components at this stage already?What about the same question regarding ESD protection (f.x. diodes), knowing that all chips on board already have some level of ESD protection on their own?Thank you

author: thm_w
author_rank: Super Contributor
timestamp: August 06, 2020, 10:48:43 pm
content: I would add footprints, even if they are not populated. Then either jumper them with a wire, 0R resistor, etc.But if you are certain its going to completely change, then maybe its not worth your time. Really up to you..You don't need ESD protection on the voltage input, but some form of overvoltage and reverse voltage protection might be necessary (eg TVS, series diode, regulator, etc.).
EMC filter components Mean Well NSD10-S - Page 1
Forum section: electronics / beginners

author: tox3
author_rank: Contributor
timestamp: April 17, 2020, 02:06:02 pm
content: Hello I am considering using NSD10-S for project, and don't have much experience with EMC filtering.Datasheet gives suggestion for EMC filter, but I am not sure what they mean by those coils - are they 2 separate 80uH inductors or something else?Also I am not sure if value is correct as 5W version has only 5.5uH, but this has 80.Maybe someone has used this converter, or could point me in the right direction.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: April 17, 2020, 02:21:32 pm
content: Yeah probably CMC. Different values for different designs, of course.Two separate inductors I don't think will be a problem.I haven't used this module specifically, but I have used other fractional-brick size modules before. One being an active-clamp flyback or (half wave) forward design using planar magnetics, which coupled a ton of noise across its isolation "barrier" -- multiple volts. The CMC was obligatory!Tim
EMC metal enclosure - Page 1
Forum section: electronics / beginners

author: Kemme
author_rank: Contributor
timestamp: June 18, 2018, 07:21:54 am
content: Hello allToday I was playing with a device which had almost all of its pcbs covered in a metal enclosure. The designer explained me that the enclosure was added to protect the pcbs against the emc fields induced by the rest of the device. He also guaranteed that this metal case 100% fits the role.But I am not sure. It had many holes in it and two big slits on two edges of the enclosure (like 15 cm long and 5mm in height). Picture below is just to visualize where the slit was located in the device.My knowledge about emc is almost 0 but I have a feeling that this long slit completely negates all efforts with adding the case. Am I right?All I could find on the internet was this:SE stands for shielding effectiveness. Does that picture prove my point?

author: Gyro
author_rank: Super Contributor
timestamp: June 18, 2018, 09:06:50 am
content: Yes, you're correct. The maximum wavelength (minimum frequency) that an enclosure hole will pass is determined by it's longest dimension.I notice that your enclosure picture shows two fixing screws along the length of the slit. As long as these joints are good and conductive, these will reduce the effective slit length. Whether you need to start looking at EMC gaskets etc. depends on the level and maximum frequency of emissions from your circuit. Remember also that conducted (and radiated) emissions from cables can be just as important.

author: mike buba
author_rank: Contributor
timestamp: July 11, 2018, 07:21:42 am
content: Sorry for raising the topic again, but it is a similar question.I am looking for pcb metal enclosures, and all I can find are just metal boxes without any holes. I assume I have to drill holes (apertures) for power supply, ADC cables, GPIO, etc. Are there any limitations on how big/how many/distance between/etc.If I look atsimpleFaraday cage design it is just a metal mesh.Also, do I have to ground metal enclosure?
EMC  of battery powered equipment in plastic box - Page 1
Forum section: electronics / beginners

author: Faringdon
author_rank: Super Contributor
timestamp: June 14, 2021, 05:01:25 am
content: Hi,We have a plastic box containign low power SMPS running off a battery (<5W)There are also comms circuits in there, with microprocessors.We need to pass radiated EMC.Do you think we will need to put the low power SMPS into a metal can, and connect this can to circuit ground?What about the comms wires?...use shielded cable for these?
EMC / PCB Design rule of thumb - Page 1
Forum section: electronics / beginners

author: hamdi.tn
author_rank: Frequent Contributor
timestamp: June 12, 2015, 08:00:23 am
content: Hi everyoneSo i have a large design that involve high voltage generation among other stuff ( a lot of analogue measurement, micro current measurement, stepper motor control and AC motor command via triac or relay ) and it's sensitive application that need some security.What am worried about is EM, for years i have read AN that talk about EM and how to immune the board from it. Still a bit a mystery for me though. So any rule of thumb when designing a board, am totally aware that it's almost every time case depending. That include ground plan, track clearance, impedance , paralleled track ... but am not sure how each parametre influence for better immunity or worst.The second thing is the micro current measurement, i saw a board that do the same and the designer separate this particular circuitry from the ground plane and put it in a separate ground plane with large clearance between both, it still the same ground cause they are connected with a single track. Does this help in anyway giving a cleaner ground reference. Does it help to put a inductor to connect both ground.Thanks

author: KJDS
author_rank: Super Contributor
timestamp: June 12, 2015, 09:58:44 am
content: In an ideal world, you'd put the microcurrent measurement in a separate screened box from everything else. If you can't do that then you'd put it in a separate screened section on the same board with no connections apart from screened leads to provide the power and signals. If you common all the grounds at one point then you'll prevent switching spikes on the ground going through your sensitive circuitry, providing you chose the correct point. Depending on the spec you require, you may not need a screened can over the sensitive circuitry, however if you lay the board out so it's possible to put in something like a Perancea enclosure on the board then it's easy not to fit it.

author: hamdi.tn
author_rank: Frequent Contributor
timestamp: June 12, 2015, 08:11:09 pm
content: Thanks for your answeri already kept some space around the uC measurement and clear of all signal except those needed for the this part of the board obviously. Putting a can over it is not releasable but common ground in one point sure is.
EMC test of a component/sub-assembly - Page 1
Forum section: electronics / beginners

author: metebalci
author_rank: Frequent Contributor
timestamp: February 22, 2024, 07:00:04 am
content: If the DUT is a component/sub-assembly (may have no enclosure), which cannot work alone or probably cannot even be powered on independently, how is the test done ? Is it somehow connected by wires to the host device staying outside ? But what happens if there is a not very long max length limit ? Also when the DUT is somehow configurable/programmable, how is the configuration/program selected, is it the one using all the hardware resources at max capacity etc. ?Some examples I can think of. A PC/PCIe card, a PXI module, a eurorack (synth) module, an eval kit (mcu, fpga etc.), an expansion board for something (like an rpi or fpga board).
EME:  Earth Moon Earth Communications - Page 1
Forum section: electronics / beginners

author: Electro Fan
author_rank: Super Contributor
timestamp: May 25, 2015, 10:21:07 pm
content: This post/thread moved to:https://www.eevblog.com/forum/projects/eme-earth-moon-earth-communications-48431/

author: VK5RC
author_rank: Unknown
timestamp: May 25, 2015, 11:44:14 pm
content: Hi EF, EME is achievable with home-brew gear, there are quite a few Hams who have EME capable stations.Probably the easier path is to get your ham ticket which will allow you to transmit a reasonable power level on a frequency where someone else is listening.Guys like vk3um ve4ma are some of the leaders in the field.There appears roughly 2 paths, first go for morse or voice level communication which needs a lot better S/N ie more power, better antenna (dish) and better receive path. The other path is to use spread spectrum techniques (computer encoding decoding) using a program eg jt65, S/N can be as low as - 18dB ie below noise and still get decode. This allows medium level eg 100w, modest antennas ie yagis, and little preamp. Activity on 140MHz JT65 ham band is quite active, building a receive only station negates licencing issues. Another area that may interest you is WSPR, another digital mode. Communicating across the globe with 0.1 W is fascinating.It is an interesting technical 'hobby'.Regards Rob

author: German_EE
author_rank: Super Contributor
timestamp: May 26, 2015, 05:20:52 pm
content: In forty years of amateur radio I've only ever seen one EME station, from the top of a bus in North Manchester. This station had ten beam antennas on a frame that allowed it to be pointed in any direction and each antenna was about three meters long. He must have had very understanding neighbors.Something like this, but it was closer to the ground.http://www.ok1rd.com/articles/8x14xp-3.jpg

author: Electro Fan
author_rank: Super Contributor
timestamp: May 26, 2015, 07:35:27 pm
content: Quote from: German_EE on May 26, 2015, 05:20:52 pmHehe - I'm pretty sure that unless I come up with a considerably smaller antenna this project won't fly with my Home Owners Association- plz join the thread which has moved to:https://www.eevblog.com/forum/projects/eme-earth-moon-earth-communications-48431/
Emergency Lights Learning Project - Page 1
Forum section: electronics / beginners

author: dcbrown73
author_rank: Regular Contributor
timestamp: April 10, 2017, 05:01:38 pm
content: Hello all,I'm getting started in learning electronics and deciding on a project that isn't too deep to start or just too simple (I've already done the LED stuff) I decided a nice little emergency lighting for my home would be a nice thing to have, but I had a question concerning relays.My thought was I would plug the device into a 120v socket and use a relay to control it's function. What I was thinking was the relay would use the house power to lock the relay in the NO state and the absents of the house power would flip (release) to NC which would engage the battery power.My dumb question is, are relays meant to function with the magnet always engaged under normal use? Does it not matter or does it stress the relay to the point of failure at some point?So far I haven't fully designed the circuit, but I suppose it would be the 120v -> transformer to voltage level for relay -> rectifier to convert to DC -> relay? I suppose I should get some software to design it. I will look for some.Thanks,David

author: Seekonk
author_rank: Super Contributor
timestamp: April 10, 2017, 05:41:48 pm
content: Relays do heat up as well as consume power. Most DC relays will pull in at about half voltage. Once pulled in it only takes about 15% power. I'd use an opto isolator pulling down a FET gate to switch on lights.

author: dcbrown73
author_rank: Regular Contributor
timestamp: April 10, 2017, 05:52:03 pm
content: Thank you, I will look up a opto isolator.

author: james_s
author_rank: Super Contributor
timestamp: April 10, 2017, 06:26:53 pm
content: A relay will work though, so long as the coil voltage supplied is within the rated range it can be left energized continuously. Small relays do not consume very much power, probably a bit more than the LED in an opto coupler but even those consume some power.

author: edavid
author_rank: Super Contributor
timestamp: April 10, 2017, 06:43:06 pm
content: Quote from: dcbrown73 on April 10, 2017, 05:01:38 pmYes. Solenoids often have on time limitations, but not relays.QuoteYou can do it that way if you want, but it's much simpler to buy a relay with a 120VAC coil.Quote from: james_s on April 10, 2017, 06:26:53 pmI looked at some AC relay datasheets, and they have coil ratings of 0.5-1VA, so not much power at all.
Emerson LC320EM2 and Sotek HD Amplified Digital TV Antenna - Page 1
Forum section: electronics / beginners

author: TNRVER
author_rank: Newbie
timestamp: April 22, 2016, 10:56:18 pm
content: Recently purchased the Sotek HD Amplified Digital TV Antenna for use in our Motorhome to get local channels while traveling. Installed it on our Emerson LC320EM2, following the instructions, by plugging the power cord into the USB port on the TV since the power cord was too short to reach the wall plug. After about an hour, the TV went black and is not getting power. I am a novice at tv repair and would appreciate any and all suggestions of things to try. Thank you.
EMF detector with substituted components not working; could it be the substituti - Page 1
Forum section: electronics / beginners

author: seanspotatobusiness
author_rank: Regular Contributor
timestamp: May 04, 2019, 02:41:36 pm
content: I'm trying to cobble together an EMF detector to trace electrical wiring in a wall. I have a live wire detector but it's a POS. The circuit I'm attempting to improvise is below. I had to substitute a few components and it's not working; I'd like to know whether my substitutions are the reason. Can I use an LM158 instead of a LF351? I also substituted a 1.9 M resistor for the 2.2 M and a 220 uF capacitor for the 150 uF capacitor. I've no idea how suitable my chosen inductor is. It's all crammed together on a breadboard so it could also be a lose connection or a short circuit (obviously I've endeavoured to eliminate any). I've also used a ready-made audio amplifier instead of making one.

author: Andy Watson
author_rank: Super Contributor
timestamp: May 04, 2019, 03:02:50 pm
content: L1 appears to be a toroid (?), i.e. for all practical purposes it has a closed magnetic path - and therefore very little interaction with an external field.

author: Brumby
author_rank: Unknown
timestamp: May 05, 2019, 02:40:37 am
content: Quote from: Andy Watson on May 04, 2019, 03:02:50 pmYes. Your "detector coil" could not be any worse.Imagine you have a slinky. The magnetic path runs down the middle of the slinky. If you have a slinky with nose to tail (like a donut), the magnetic path runs around in a circle, not interacting with the outside world very much.What you need is a slinky just sitting flat - the way it came in the box - with two open ends. The magnetic path runs through the middle of the slinky (just as before) but now has to turn around and wrap outside the slinky to get back to the other end - and this hugely interacts with the outside world.In short, you need a flat coil (a very short slinky).

author: seanspotatobusiness
author_rank: Regular Contributor
timestamp: May 05, 2019, 09:44:52 am
content: Thanks very much. I've replaced the coil but it still doesn't seem to work. I tried putting the coil next to a CFL lamp cable and next to a 2.5 mW Bluetooth amplifier. Could I connect the coil leads to something to test if that gives a signal?
EMF transmission lines from dC to Star light - Page 1
Forum section: electronics / beginners

author: Beamin
author_rank: Super Contributor
timestamp: April 05, 2018, 01:25:00 pm
content: I'm making a poster with what things go through. I am not sure what different HZ use and what makes the cut off from say metal to glass seems like a rather sudden jump. Facinationg is the how and whay the meterials change.DC= wires1MHZ=coax1Ghz= special coax?10GHz=?rigid coax300GHz=? wave guides/strip line?Millimeter=?Fr IRNr IRRed500nm Light= glass quartz fibers?UV = quartz fibreSoft Xrayxray=? Wave guides?Hard Xray=?Gamma=?I might make it extra gurly just for our mainy male demographic so they can get in touch with their feminine side!

author: Cliff Matthews
author_rank: Unknown
timestamp: April 05, 2018, 01:44:50 pm
content: What is the focus? (health related perhaps?) Can you post a sample of what you've drawn so far?