hybridfree/eevblog-posts huggingface dataset:
Ask dozens of successful hardware startup founders your burning questions! - Page 1
Forum section: electronics / beginners

author: leftsharq
author_rank: Newbie
timestamp: February 05, 2015, 08:12:20 pm
content: "The discipline of building hardware at scale is not something you can easily learn at school, even at university. While the path (e.g. tools, knowledge base, peer community) to become a good software developer is readily available to all in this Internet age, this is not true yet for hardware development.” - Eric Klein (Lemnos Labs)The explosion of hardware startups has left many aspiring entrepreneurs and hardware makers thirsting for knowledge on how to build and sell amazing products themselves.We’re very excited to announce that several dozen hardware startup founders have graciously agreed to help answer your questions. They’re from companies like Fitbit, Whistle, Zen, Spark, The Orange Chef, Misfit and many more! They have experience with a variety of products including wearables, smart thermostats, trackers, and cameras. They’re happy to contribute their expertise on everything from crowdfunding, prototyping, design, manufacturing, business development and anything else you can think of! To participate in the Hardware startup founder Q&A, please submit your questions to the link below.http://forum.upverter.com/c/startup-questions]http://forum.upverter.com/c/startup-questions

author: free_electron
author_rank: Super Contributor
timestamp: February 05, 2015, 10:22:33 pm
content: the problem is finding suppliers that have the right technology.for example : apple uses a technique whereby they microperforate aluminum so light can shine through it without you seeing a visible openingwho offers that as a service ? i have a product where i want to make an aluminum enclosure and have illuminated text that shines through the aluminum.
asking about buying oscilloscope  - Page 1
Forum section: electronics / beginners

author: smarty551
author_rank: Newbie
timestamp: November 04, 2017, 12:48:26 am
content: hii wanted to ask about which is better ds1052e or hantek dso4104bthose are the only 2 devices i found with my budget as the shipping rates to egypt are high and i only have about 340$the rigol is a bit old and there's no much reviews about this hantek dso4104bi hope you can help me choosing and if there another optionsthanks

author: Electro Fan
author_rank: Super Contributor
timestamp: November 04, 2017, 05:41:20 am
content: Maybe save a bit more for this:https://www.batronix.com/shop/oscilloscopes/Rigol-DS1054Z.html

author: smarty551
author_rank: Newbie
timestamp: November 04, 2017, 10:07:56 am
content: that will take to long i'm still engineering student

author: daybyter
author_rank: Frequent Contributor
timestamp: November 04, 2017, 02:18:53 pm
content: Maybe look for a used 1054z? Rigolna clearance sale, or so?

author: smarty551
author_rank: Newbie
timestamp: November 04, 2017, 03:59:59 pm
content: that's helpful but the shipping will cost too much

author: mavu
author_rank: Contributor
timestamp: November 04, 2017, 04:46:30 pm
content: Quote from: smarty551 on November 04, 2017, 03:59:59 pmTry to get a job at your engineering department as a course helper or anything really. Even if it does not pay much, such jobs usually get you access to labs to play with all the nice equipment they have. (at least it did im my day)
asking about midi to uart interface with 6n137 - Page 1
Forum section: electronics / beginners

author: walidantar
author_rank: Newbie
timestamp: May 30, 2025, 09:30:48 pm
content: hello, based on schematics i found on web i'm trying to solder on a perforated board a midi to uart interface with 6n137, i got confused as a schematic mentioned a 220ohm resistor to be placed at pin 5 of the midi-in din connector (at the anode side of the diode) and some of the schematics mentions the resistor to be placed at pin 4 (at the cathode side of the diode) .. as i under stand, schematics should have meant the back-side of the connector where the pins are exposed .. which one is the correct one .. anad what if i put resistors at both pins?

author: wraper
author_rank: Unknown
timestamp: May 30, 2025, 09:33:53 pm
content: Quote from: walidantar on May 30, 2025, 09:30:48 pmIt does not matter whatsoever which variant you chose because either way it's in series with optocoupler's emitter/diode which are not connected to anything else.

author: walidantar
author_rank: Newbie
timestamp: May 30, 2025, 09:37:33 pm
content: thanks you, but sill curious, is it ok to put at both sides 220ohms? or the value of the resistor would affect?

author: wraper
author_rank: Unknown
timestamp: May 30, 2025, 09:42:53 pm
content: Quote from: walidantar on May 30, 2025, 09:37:33 pmTo keep current the same, you'd need to reduce resistance in half. Anyway, there is zero benefit in using 2 resistors with optocoupler. It' would be just a waste of parts and space.

author: Andy Watson
author_rank: Super Contributor
timestamp: May 30, 2025, 11:01:53 pm
content: Overall, you are creating a circuit that drives a few milliamps through the diode in the 6N137. The first hit I found on the web suggests that the standard current is 5mA. There is 220in the reciever, and two 220in the transmitter, giving a total of 660. 5mA through a 660gives a voltage drop of 3.3V. This leaves 1.7V across the diode (assuming a +5V power supply) - slightly more than necessary but within the right ballpark.The reason that the 660is distributed across three resistors is that, with careful placement, it mitigates against the effects of short-circuits on the midi connectors and/or connecting together midi devices that do not conform with the standard.

author: walidantar
author_rank: Newbie
timestamp: May 30, 2025, 11:42:58 pm
content: thanks you all
Asking for resources on power electronics. Inverters and chargers - Page 1
Forum section: electronics / beginners

author: Albert Luna
author_rank: Newbie
timestamp: November 02, 2020, 01:12:04 am
content: Hi, I am actually working at a inverters workshop assembling and troubleshooting inverters, I study at a technical school here in my country and I want to get more into the world of power electronics on that specific area, contents can have mathematical analysis, something like electronic principles of Malvino kind of book.I would really appreciate itThat inverter is not my design or anything I assemble them and troubleshoot them in a man's workshop

author: Doctorandus_P
author_rank: Super Contributor
timestamp: November 02, 2020, 02:14:17 am
content: https://html.duckduckgo.com/html?q=10kw+solar+inverter+reference+design
Asking the impossible to an ATmega 328P: mimicking a differential input ADC - Page 1
Forum section: electronics / beginners

author: Houseman
author_rank: Regular Contributor
timestamp: March 15, 2021, 05:25:34 pm
content: Hi folks.A device outputs constant current (adjustable) pulses as square waves with fixed value of -15V. Such a device is used to test corrosion of electrodes, so the output is plugged to two electrodes in solution and injects in the first phase lasting 500us (active phase) a current of -25mA relative to ground, the other phase it shorts the output to ground so the current flows back.A blocking capacitor is used to limit the charge on the electrode, resulting, as a first approximation in a RC charge and discharge circuit. C is the blocking capacitor in series with the electrodes (usually a couple of uF) and the resistance is represented by the electrodes themselves (approx. 1k).What I have to measure is the current that flows back and forth (range from 0 to +-30mA), and that the circuit it is effectively working: an increasing value of the resistance of the electrodes means that the corroding phase has begun until it breaks.so the "simplest-but-not-sufficent" idea was to measure the voltage drop across a known value resistor in series of the electrodes (let's say 200 ohms) and read it through the ADC. But.It is in the range of 0 to -15V.There is a short pulse lasting 500/600 us.The value of the Voltage of the blocking capacitor is around 900mV at the end of the active phase.Do You have any idea how to implement such a device using only the ADC input of the ATmega328P?Any hints are appreciated.Thank you all

author: ledtester
author_rank: Super Contributor
timestamp: March 15, 2021, 05:46:10 pm
content: QuoteWhat voltage rails do you have available?

author: MLXXXp
author_rank: Frequent Contributor
timestamp: March 15, 2021, 05:49:00 pm
content: Are you able to add an op amp to condition the signal, to provide an output suitable for an ADC input?This isn't exactly what you're looking for but may be useful:https://youtu.be/OlhN7ADpKds

author: mvs
author_rank: Frequent Contributor
timestamp: March 15, 2021, 05:57:46 pm
content: You have probably implemented some sort of H Bridge. Current sense resistors are usually placed between source/emitter of low side MOSFETs/BJTs and ground.

author: Houseman
author_rank: Regular Contributor
timestamp: March 16, 2021, 09:26:54 pm
content: Quote from: MLXXXp on March 15, 2021, 05:49:00 pmuh.. W2AEW.. I adore his way of teaching electronics...Thank you for the link but this is not really suited for my case.Thank you
Aspiring AI Student Seeking Guidance on CPU/GPU Design and IC Development - Page 1
Forum section: electronics / beginners

author: Tarikko
author_rank: Newbie
timestamp: February 03, 2025, 07:38:31 pm
content: Hello Community,I hope this message finds you well. My name is Tarik, and I am currently a first-year student at the National Higher School of Artificial Intelligence in Algeria. While my studies are focused on AI, I have a deep passion for electronics, particularly in the fields of CPU and GPU design, as well as integrated circuit (IC) development.My dream is to contribute to the next generation of computing technology, whether that be through designing a groundbreaking CPU, GPU, or developing a new IC that could potentially lead to a patent. I am reaching out to this knowledgeable community to seek your advice on how to best achieve my goals.Here are a few specific questions I have:1.Educational Path: Would pursuing an additional master's degree in electronics or a related field be beneficial? If so, what specializations should I consider?2.Research Opportunities: Are there specific areas of research in AI and electronics that you believe hold great potential for innovation? How can I get involved in such research?3.Skills Development: What technical skills or tools should I focus on mastering to prepare myself for a career in CPU/GPU design and IC development?4.Networking and Resources: Can you recommend any resources, forums, or communities where I can connect with professionals in the field?5.General Advice: As a first-year student, what general advice do you have for someone like me who is eager to make a mark in the electronics industry?I appreciate any insights or advice you can share. Thank you for your time, and I look forward to your responses!Best regards,Tarikhttps://www.tarikben.com

author: I wanted a rude username
author_rank: Frequent Contributor
timestamp: February 04, 2025, 12:49:47 am
content: Regarding general advice:Work on interesting personal projects and put them on your GitHub accountTry to get internships that are at least somewhat related to your chosen fieldCreate a résumé on a clean, not generic template, which mentions points 1. and 2.Apply to many job postings

author: Marco
author_rank: Super Contributor
timestamp: February 04, 2025, 08:06:21 am
content: Hard to predict where opportunities will be in a couple of years. Also hard to predict where regulation will go.For the near future I think there's opportunity in research for edge/local. MoE and PTQ are opening up opportunities to run large open weight models at the edge, with the parameters stored in flash and only the working set in DRAM.

author: benj38
author_rank: Frequent Contributor
timestamp: February 04, 2025, 01:36:03 pm
content: Quote from: Tarikko on February 03, 2025, 07:38:31 pmLooking at the online published curriculum of your school, I am afraid it will do little to nothing in providing you education relevant to your dream. A degree in electronic engineering, with a correct focus in the elective courses, would be much more appropriate.
Assembly, Atmega 328 PWM, phase correct mode - out of range problem - Page 1
Forum section: electronics / beginners

author: Mikelinius
author_rank: Newbie
timestamp: January 20, 2022, 05:38:00 pm
content: Hi,I'm new into assembly and I need to generate in PWM, phase correct mode signal with frequency 255 Hz and FF 55 % but I have problem with Atmega328 - you can see in the screen what is wrong. But what's more - my code works for Atmega32. It looks like I use some kind of bad instruction, but I've no idea what exactly is wrong. Do you have any idea what's wrong?.include"m328def.inc"SBI DDRB, 3LDI R16, 140 // Fill factor 140/255 = 55%OUT OCR2A, R16LDI R17, 0b00000001 //PWM PCout TCCR2A, R17LDI R18, 0b00000101 //prescaler 128out TCCR2B, R17loop:rjmp loop

author: Kleinstein
author_rank: Super Contributor
timestamp: January 20, 2022, 05:43:13 pm
content: The newer Megaxx8 have many of the registers at different locations and some of the timers get out of the range of the OUT instruction. So one would need to use STS instead.For some reason they had (not sure if fixed) some of the examples in the datasheet also wrong in this aspect.Some of register names also changes, though to a large part same funtionality as the mega32.

author: Skashkash
author_rank: Regular Contributor
timestamp: January 20, 2022, 05:49:05 pm
content: Quote from: Kleinstein on January 20, 2022, 05:43:13 pmWas about to say exactly the same.I've taken to using the following macros so I don't have to keep track of the register address.(These may not be appropriate for the more modern chips or newer versions of studio.)Code:;--- in for any port address.macro in_reg.if@1<0x40in@0,@1.elselds@0,@1.endif.endm;--- out for any port address.macro out_reg.if@0<0x40out@0,@1.elsests@0,@1.endif.endm
Cable/Connectors Assembly - Page 1
Forum section: electronics / beginners

author: waulu13
author_rank: Newbie
timestamp: October 29, 2020, 02:13:43 pm
content: Hello,I have to connect a motor to a controller. For the controller I have to use a 14 miller connector, so I am gonna buy this one from the manufacturer,https://www.kellycontrollers.eu/kbl-j2-cableFor the motor there's a rectangular connector with 6 pins, so I will buy this female connector 6 pins,https://www.kellycontrollers.eu/csatlakozo-kelly-6pin-vizalloBetween the controller and the motor I only connect 4 pins through the rectangular connector, everything else I connect to a PCB/Perfboard and one wire from the miller connector to a circuit breaker.So the diagram is like this,|Controller (14 miller)->6 wires->male rectangular connector->|female rectangular connector->4 wires->motor| |female rectangular connector->2 wires->PCB/Perfboard|Controller (14 miller)->9 wires->PCB/Perfboard|Controller (14 miller)->1 wire->Circuit BreakerAs I don't have much experience with cables/connectors, what connectors should I use to connect the wires to the PCB/Perfboard and to the Circuit Breaker. Also, I don't understand how I will join the rectangular connector to the cable with the 14 miller connector.Meanwhile I will make a drawing to try to clarify my diagram.Best regardsEDIT: I don't know how to delete the first attachment. They are the same diagram but I made an error on the first one.
assembly planning (remember do SMD first) - Page 1
Forum section: electronics / beginners

author: JWoodrell
author_rank: Contributor
timestamp: March 07, 2017, 04:25:56 pm
content: hey guys I just wanted to put this here as a reminder to other new guys. put the SMD parts on first before doing the tall cable connectors, hand soldering into a canyon is frustrating at best.this is an interconnect board I am making for someone, making 15 of them.also I was proud of the routing i got done almost all the pins are used. admittedly i did start with the auto-router but had to redo most of it by hand.
Assessing big, old, capacitors' conditions (Capacitance/Leakege/ESR) - Page 1
Forum section: electronics / beginners

author: Noxy
author_rank: Newbie
timestamp: February 07, 2020, 03:29:56 pm
content: Hi everyoneI'm looking for advices on my methodology for checking up the conditions of a bunch of large electrolitic caps, ranging from 33000 to 500000 uF, I've stockpiled in a couple of decades of salvaging linear equipment. Just to check if there's still something usefull in that colorful pile of cans or if they are just taking usefull space.Keep in mind I'm a mere hobbist, seriously equipped , but still an hobbist.Since these caps are way to large for my dedicated test gear, I obviously have to test everything manually.I start by slowly charging each cap overnight while limiting the current to 10-100mA depending on the rated capacitance.The following day I check the leakage current by measuring how much current is still flowing into the cap at its rated voltage.Not much to say about the capacitance, I just charge the cap through a suitable resistor, check at the oscilloscope how much time it took to reach 63.2% of the maximum voltage then do the math using the RC time constant.As for "estimating" the ESR, I feed a 1 Vpp 100/200kHz square wave to the capacitor through an RG58 coax while measuring (through a regular oscilloscope probe) the residual Vpp of the square wave at the cap's terminals. Then I use the residual Vpp to calculate the resistance by voltage divider: R= "residual Vpp" x "signal generator impedance" / (Input Vpp - residual Vpp)On smaller caps, I've tested this method against the readings I get from my ESR meter, and I must say it works pretty well.I there anything else I should do or change to have a better view of the state of healt of the capacitors I'm going to test?Is it safe to consider "good" an old electrolitic capacitor if the above parameters are within specs?

author: AVGresponding
author_rank: Super Contributor
timestamp: February 07, 2020, 03:41:12 pm
content: As long as they've not been stressed by excess heat, voltage, reverse V, or ripple current, and they are good quality brands, they are probably good to use. I've got recovered Rubycons, Elnas, BHC etc that still test good at 30 years+ old.The frequency you're using seems high for such large value caps though, my LCR819 recommends a test frequency of 100-120Hz above 1uF
assignment time again transmission lines. - Page 1
Forum section: electronics / beginners

author: Simon
author_rank: Unknown
timestamp: April 16, 2017, 11:23:17 am
content: what I think I've managed most of this assignment on my own. I'm on the last part of the last question. I have been given an A B C D set of parameters for a power transmission line at 50 Hz. The power received or rather the voltage received is 88 . 9 KV and I am asked to work out sending voltage and power loss in the line which I have. The second part of the question tells me that the line is to be considered is made up of a succession of T type sections and that it is 50 km long. I am asked to find out the RGLC parameters.Is this very difficult? Looking back through my course material I have at the beginning of the study of transmission lines a matrix formula that explains how to obtain the a B C D parameters knowing the impedances (I assume complex impedances) of the 3 branches of the T network. Is there a way of reversing this or is it very complicated? This is kind of looking something like a simultaneous equation whereby I would find a set of primary coefficients that match the a B C D coefficients in the particular configuration. I have no idea if Microsoft Mathematica is capable of handling this sort of thing although it can do matrixes.
Assistance needed on a schematic - Page 1
Forum section: electronics / beginners

author: mitrynicolae
author_rank: Contributor
timestamp: June 04, 2019, 06:09:26 pm
content: Hello everyone,Could someone please describe to me as detailed as possible on how the attached schematic work?The schematic is from a comparator and I have identified the following subcomponents:-q7, q8 are forming a current mirror-q1-q2 and q3 q4 are darlington pairs-q5 is the open collector output.What it is not clear is-how exactly the inputs are compared (a detailed explanation will be very appreciated) (from my understanding if positive voltage is applied for example to q1 then the transistor is off. If this is true then how is the comparison performed?)-if in+ is greater than in- what is the value of the output (floating or connected to ground)?

author: soldar
author_rank: Super Contributor
timestamp: June 04, 2019, 06:38:36 pm
content: You can see two similar halves. As long as both inputs are the same the collectors of Q2 and Q3 have the same current. Now vary -input and it will cause the collector current of Q3 to vary and this difference will go to the base of Q6.
Assistance on identifying components - Page 1
Forum section: electronics / beginners

author: jefti
author_rank: Contributor
timestamp: April 10, 2017, 02:11:28 pm
content: Hi all,I am busy on reverse engineering a PCB from a radio direction finding antenna. My prototype is about 90% done, and I would like some opinions on my component identification.In the first picture, I believe that the green component is a 1 uH inductor, like this one:http://www.ebay.com/itm/10x-Drossel-radial-1-H-2-5A-RM5-7-5x11mm-LHLC06TB1R0M-1uH-/231227036049?&_trksid=p2056016.m2516.l5255Also in the first picture, I believe that the capacitor is a 10 PF one. Is this correct? What does the point behind the 10 mean?In the second picture, I believe that the capacitor is a 100 pF one, again, is this correct?Thanks for your time!

author: Trooper_Dan
author_rank: Newbie
timestamp: April 10, 2017, 04:46:53 pm
content: Yea those are caps I believe the value is correct u can check Google for 10pf in the futureSent from my SM-N920T using Tapatalk

author: PA0PBZ
author_rank: Super Contributor
timestamp: April 10, 2017, 06:13:40 pm
content: I think you are correct with the values. I also noticed that the other 2 components have the same dot, why I have no idea.

author: jefti
author_rank: Contributor
timestamp: April 11, 2017, 07:48:48 am
content: Thanks for the input guys. I think i'm on the right track then.One more thing, there are a couple of Baluns visible on the picture. Is there a way that an amateur like myself can analyse these? I've found some that are reasonably similar in size, but I believe that the material also makes up a great part of the specs. I do have some signal generators and oscilloscopes laying around, only no spectrum analyzer or anything. Any input would be helpful.
Assistance selecting hardware/software for computer vision project - Page 1
Forum section: electronics / beginners

author: Turbine_Lust
author_rank: Newbie
timestamp: April 21, 2017, 01:35:28 am
content: Hello, thanks for having such a great resource. I am quite green when it comes to the electronics side of things and have realized that with such little knowledge its hard to approach people who are knowledgeable and be taken seriously. When googling the hardware and software options this forum keeps popping up so i figured i could ask a few questions here to get myself going in the proper direction.My goal is to have a piece of equipment that can be controlled remotely via a web page similar to (http://runmyrobot.com/) without being public. It will need to stream some data numerical data as well as video but the frame rate doesn't need to be more than say 5fps. If the data connection is lost id like the equipment to function on its own autonomously. This is basically a robot for locating hot spots.HardwareNvidea Jetson TX2 DevKit3X FLIR Boson 320 × 256 (or possibly Lepton 160X120) connected via USB/\ I assume the Jetson can handle these cameras through USB? Hoping to get a panoramic view of the horizon.3X Motor Driver 15A IRF7862PBF/\ connected via GPIO's4g USB stick from (T-mobile, AT&T, Verison, etc)USB Hub15X 0-3.3V data sensorsSoftwareUbuntu, Python 3, and Open CVThe jetson is listed as having 4bit GPIO not real sure what this means. An unboxing video quotes "40 GPIO pins" IIRC. If i need more GPIO's can i just add an Arduino, or Beagle Bone?Am I on the right track? Im currently working my way through some Python, and Open CV tutorials and i feel like this combo will at least get me going until i can hire a programmer to make everything really work well together and add features with time.I really appreciate everyone's time,Grant
Assistance with programming MCP3903 - Page 1
Forum section: electronics / beginners

author: Christos1024
author_rank: Newbie
timestamp: July 10, 2013, 01:44:02 pm
content: Hi EveryoneI'm very new to the world of programming. I would like to design a 3-phase energy meter for my final year project using MCP3903 and a dspic33f chip. I've started programming the dspic but I'm struggling to find a starting point for the MCP3903. I cant find any help on MPLAB X on how exactly I would go about starting programming for the MCP3903. I would like assistance on where do I start to look for the libraries and a step by step instruction on how to start with the programming. Any help with the c code will be much appreciated as well as code for power, voltage and current computation on the dspic.Thank you

author: HackedFridgeMagnet
author_rank: Super Contributor
timestamp: July 10, 2013, 02:27:38 pm
content: try a google search SITE:eevblog.com MCP3903,funny the site search doesn't return much?here are a couple of resultshttps://www.eevblog.com/forum/projects/power-quality-monitor-work-in-progress/eevblog episode #409or if all else fails look at the reference design, that or maybe there is one for the 3901Quotebut really, what happened in the first years of your course?to talk to this chip you need to use SPI.

author: plex
author_rank: Newbie
timestamp: July 11, 2013, 12:25:47 pm
content: Have a look here at the bottom of the page.http://www.microchip.com/pagehandler/en-us/technology/powermonitoring/exampledesigns/multipleloadshunt.htmlIt should get you started.
Assistance with xcircuit drawing app required. - Page 1
Forum section: electronics / beginners

author: Jim-0000
author_rank: Regular Contributor
timestamp: May 18, 2019, 04:02:25 am
content: I have downloaded xcircuit, read the first part of the user manual, and started to draw a simple circuit.However, I have been unable to find a wider range of component in the library, (or another library?) other then what is shown in this limit range in the included library.Can someone offer advice of how to find more component symbols to include in my circuit?I only want the more common ones like triac, mosfets, regulators (such as TN431 etc.).Jim.

author: MarkF
author_rank: Super Contributor
timestamp: May 18, 2019, 04:17:39 am
content: I would recommend you useDipTraceorKiCadinstead.After you build the circuit, you can proceed to laying out a PCB for manufacture.All parts and 3-D view of PCB for review.

author: Jim-0000
author_rank: Regular Contributor
timestamp: May 18, 2019, 08:38:09 am
content: Quote from: MarkF on May 18, 2019, 04:17:39 amOk thanks.I will look at them now.Edit: I found KiCad in the Linux Mint repository. Quick installation.
Associate's Degree in EE (jobs) - Page 1
Forum section: electronics / beginners

author: renzoms
author_rank: Regular Contributor
timestamp: August 28, 2020, 01:50:44 am
content: I’m preparing to earn a job after this semester and I’d like to know what positions I might like, recommendations, and insight into a job that will be the bridge between my associates degree and future degree(s). Below, I can post my linkedin bc it has my work experience and education. I’ll also describe it here.I started EE by going to Penn State University for 2 years. I did alright. Between us, I going to class high, partying, not being a role model student. I can post the transcript below, too. I took 3 year gap and worked a few jobs; logistics and catering, bartending and serving, included a highly ranked fine dining restaurant that was the best job I ever had. Around the second half of the 3 year gap I picked up my notebooks from PSU and started reviewing. I ended up at the library. I ended up buying a new book. I ended up buying textbooks, and a lab. I ended up among completing every exercise in an electric circuits textbook, a digital logic w/ verilog textbook, and 4 classes from MIT’s OpenCourseWare, single variable calculus, multivariable calculus, differential equations, and (3/4s of linear algebra). I ended up with a 4.0 last semester and I have one more semester to go until I have all of my credits for an associates degree in EE. I think I’ll get a 4.0 again. And I’m going to complete these textbooks.I can’t afford to earn a Bachelor’s rn, so here I am, learning what job positions I might like, recommendations, and insight into EE.I feel smart. I like the electric circuits more than the digital logic right now. I want a job that will supplement my growing career and compliment what I have done.
Astrange circuit that I can't get - Page 1
Forum section: electronics / beginners

author: vaualbus
author_rank: Frequent Contributor
timestamp: June 14, 2014, 02:50:32 pm
content: While I'm try to repair my HP 33120A function generator (https://www.eevblog.com/forum/testgear/a-broken-hp-33120a/msg438250/#msg438250),I come across some circuit that I can't get.What do CR1002 in this circuit?

author: PE1RKI
author_rank: Regular Contributor
timestamp: June 14, 2014, 03:03:34 pm
content: a protection diode ?also the zener is there to protect the -5 volt line.if the -18 volt drops down to 0 volt during power down, the -5 volt will be forced to go down as well.

author: nuhamind2
author_rank: Regular Contributor
timestamp: June 14, 2014, 03:09:36 pm
content: Aren't that a clamping diode, so the voltage at that part won't exceed 18V or less than -18

author: SeanB
author_rank: Super Contributor
timestamp: June 14, 2014, 03:17:36 pm
content: Basically it makes sure that during power up or power down the Vee supply cannot exceed the positive or negative power rails, so that the internal substrate diodes of the semiconductors will not have enough current to turn on parasitic SCR structures inherent in the design of the silicon.Wind a standard 4000 series CMOS input above or below the supply rail and let the input diode conduct over 50mA and it may turn on this parasitic SCR. Over 100mA most devices will turn on and essentially short the supply rails together until the power is removed or the chip melts and burns out. Same with an output as well, but there it becomes somewhat dependant on the logic level there and if it is tristated.Might be a good short video to demonstrate this.

author: vaualbus
author_rank: Frequent Contributor
timestamp: June 14, 2014, 03:53:04 pm
content: Thanks for the answers!

author: SeanB
author_rank: Super Contributor
timestamp: June 14, 2014, 04:02:59 pm
content: Looks like an old video from Dave, made in the old garage lab, has the answers.
ASUS A2500D Laptop, how to access the CMOS battery?? - Page 1
Forum section: electronics / beginners

author: CaptDon
author_rank: Super Contributor
timestamp: April 19, 2024, 02:52:51 am
content: I can't find any useful information on the internet. The unit works but I have to hit F2 to accept the default CMOS settings, F10 to save and exit and it boots fine. I'd like to replace the CMOS battery but can't locate it. I found the RAM modules under the keyboard and the hard drive is an easy swap. Thanks for any links or info!!

author: coromonadalix
author_rank: Super Contributor
timestamp: April 20, 2024, 07:37:24 pm
content: should like this motherboard photocpu sidei just searched on Ebay ... 2500D 2500L motheboard ...

author: CaptDon
author_rank: Super Contributor
timestamp: April 20, 2024, 10:09:04 pm
content: It's close enough to help me. The hard drive and ram access were simple but the CMOS battery looks like a P.I.T.A., oh well, got to do what you got to do. The only reason I'm messing with something this old is that it has an actual German keyboard and my wife brought it here from Germany around 2007. Thanks!! I'll tear it apart on Sunday.

author: coromonadalix
author_rank: Super Contributor
timestamp: April 21, 2024, 12:56:18 am
content: sad you have to rip it apart, i think the "under the keyboard" mentality was not there at the time

author: CaptDon
author_rank: Super Contributor
timestamp: April 22, 2024, 02:03:54 am
content: After half an hour of removing screws only to find the motherboard remained attached to the base plate and the CMOS battery was still unreachable I put it all back together, took it out to the garage and used a Dremel with a router bit to cut a door in the bottom cover!! New battery installed!! Used a very thin piece of P.C.B. to make a cover held with two tiny self tapping screws. Almost looks like it came from the factory that way!!
Asus GTX 1060 dual, How to get SMD ceramic capacitor measurement/values? - Page 1
Forum section: electronics / beginners

author: deadmanwalking
author_rank: Newbie
timestamp: September 21, 2018, 05:43:13 am
content: In view that I was very successfull about thehttps://www.eevblog.com/forum/beginners/to-know-a-mosfet-values-in-a-gtx-760/I found another one that has a similar problem, so I decided to buy it, the issue is that it has 5 SMD components and also has 2 broken solder pads where the 5 component was...Investigating, I discovered that all the missing components are SMD ceramic capacitors 0603, looking some charts in google found that them can have a value from 10pf to .47uf, which leads me to my questionhow do I determine the value of a SMD ceramic capacitor?luckily I have access to a working video card of the same model and brand, where I can measure the capacitors that the other one have missing, but just like in the card that I repaired a few days ago THERE ARE NO DIAGRAMS, so my only hope is to be able to measure existing capacitors.My only tools are a Chinese soldering iron MXN$80 (the ugliest and cheapest) and a 535-339 radox multimeter MXN$300, but this GTX 1060 6Gb card worth it (approximate value of MXN$5000) so I bought a USB microscope to make repairs on the broken tracks and pads (incredible that I found in mercadolibre one for MXN$350 although it seems to work only 3 times, according to youtube reviews it serves the purpose).

author: xani
author_rank: Frequent Contributor
timestamp: September 21, 2018, 01:21:29 pm
content: Zero dollar version: make an oscillator using the cap and calculate its value based on resulting frequencyEasiest version: LCR meterEasy cheap version: Get one of those $10-20 component testers and use that to measure it:https://www.aliexpress.com/w/wholesale-component-tester.html

author: deadmanwalking
author_rank: Newbie
timestamp: September 21, 2018, 07:30:30 pm
content: Xani, thank you very much for the hint, I gone with one of thishttps://www.ebay.com/itm/Tester-Tweezers-SMD-RC-Auto-Scan-Smart-Resistance-Capacitance-Diode-Meter-OK/332587918883?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649I believe it can be useful for more than this repair, the bad news are that it arrives untill november 15th, in Mexico they are so expensive that defeats the purpouse of learning while saving some bucks, but sure I can wait a couple months, while I'll work in other projects
Asus PRIME B450M-A II AMD AM4 build doesn't work with 4 CORSAIR Vengeance LPX - Page 1
Forum section: electronics / beginners

author: Lizzie_Jo_Computers_11
author_rank: Regular Contributor
timestamp: August 12, 2021, 02:05:54 am
content: My motherboard is an Asus PRIME B450M-A II AMD AM4.The RAM is two 2x8GB 3600MHz CORSAIR Vengeance LPX DDR4 kits.The computer turns on normally if I only have two of the RAM sticks inserted, and it doesn't matter which two. I was able to get it running with two of them, take them out, and replace them with the other two, and it boots up successfully again. It only seems to be when all four are inserted that there is a problem.I can hear and see that the computer has "turned on" when this happens, but there is no display.I can't figure out what I might be doing wrong, or if there's some reason that these parts are just not compatible in that capacity.Any help or advice would be much appreciated.

author: beanflying
author_rank: Super Contributor
timestamp: August 12, 2021, 04:02:27 am
content: Interesting the 4x8 isn't on the supported vendors list but 2x8 and 2x16 is soif your MB has the latest BIOS and is no go then likely it is a bust?There are versions of 4x8 Corsair LPX running at 2800 on there as approved.https://dlcdnets.asus.com/pub/ASUS/mb/SocketAM4/PRIME_B450M-A/Memory_QVL_for_AMD_Ryzen_5000_G-Series_4DIMM_20210625.pdf

author: Lizzie_Jo_Computers_11
author_rank: Regular Contributor
timestamp: August 12, 2021, 04:24:23 am
content: I just wanted to make a small correction/clarification to my original post.They are four sticks in total, each an 8GB stick.To be exact, I have two of these kits:https://www.amazon.com/gp/aw/d/B07RM39V5F?psc=1&ref=ppx_pop_mob_b_asin_titleI'm not sure if that makes any difference, but I wanted to be precise.The motherboard is supposed to be able to support 64GB of RAM and DDR4, from what I understand which, which should be enough for this.
ASUS smartphone screen replacement - Page 1
Forum section: electronics / beginners

author: Rick Law
author_rank: Super Contributor
timestamp: February 06, 2017, 09:59:07 pm
content: Well, it is bound to happen some point in time. My kid broke the screen on her phone (ASUS Laser 2 ZE551KL). I've worked on Tre650 replacing everything that could be replaced - keyboard, screen, etc. But that old dinosaur uses screws.I am thinking about getting the screen replacement for the ASUS and give it a try, but I don't have gluing experience. I found a lot of video on youtube, but I like to hear some real 1st person experience.- What is my luck if all I have is a hair-dryer for heat?- I want to take out as little as I can - I plan to remove the battery but not the CPU board. I assume hair-dryer heat should be ok? The soldering should not melt with hair-dryer.- What is a good choice for glue? I see B7000 advertised a lot and is available from Walmart. What is your view.- What pit faults awaits me? What should I look out for?Glad to hear from anyone with screen replacement experience here.ThanksRick
Asynchronous pulse generator - Page 1
Forum section: electronics / beginners

author: Eudoxus
author_rank: Newbie
timestamp: October 22, 2015, 11:50:04 pm
content: So I've been out of the electronics game for a while, and I wanted to run this circuit past you guys to make sure I'm not doing anything dumb...A project I'm working on needs a pair of matched 5V square waves, 5-10kHz, 180 degrees out of phase. It's a quick-and-dirty, jellybean and veroboard type of gig, so nothing too fancy. I decided to use a 555 and LM393. I thought about using a CD4096, level-shifting the 555's output down, but the comparator method seemed more fun.Sorry the schematic's slightly messy. Please tell me if I'm making any rookie mistakes. Like I said, it's been a while...

author: T3sl4co1l
author_rank: Super Contributor
timestamp: October 23, 2015, 01:43:29 am
content: Not sure why the thresholds... they aren't quite right.The outputs need pull-ups, because the comparators are open collector type.The bottom 393 has negative feedback. It may oscillate on the switching edge. LM393 is a little bit faster than the 555, so it may be fine anyway (certainly without the feedback resistors), or it may make one or two extra pulses during the edge.If the frequency is quite low, simply using a logic inverter will do. 74HC04 is fine at 5V. Use a CMOS 555 and you can run the whole thing from +5V without worrying about dividers between stages.If you don't mind discrete solutions, this is accurate within 20ns or so between rising and falling edges:A couple values would have to be changed to run from a 555 and at 5V.If you don't mind buying ICs, a CD4047 will work on 5 or 9V, and does precisely what you want, out of the box.Tim
AT COMMANDS question - Page 1
Forum section: electronics / beginners

author: Kemme
author_rank: Contributor
timestamp: July 05, 2017, 10:44:29 am
content: Hello guysI am using SIM808 module to send data via GPRS and to receive phone calls.My biggest problem is that when the module is in the middle of GPRS session and in the same time it receives a call it all gets very dirty. It happens because I monitor if data was sent with success or not.What I do now is to set AT+GSMBUSY=1 before GPRS session and AT+GSMBUSY=0 after so the two session won't interrupt my monitor procedure. It is ok but still not perfect since for a short time (while GSMBUSY=1) it is not possible to make a call to the device.So I have two questions:1. Is it possible to disable RING notification? It would be perfect because I could disable it before GPRS session and enable it afterwards. The caller would just wait a little bit longer without being disconnected.2. If above is not possible. Is it possible to indicate that someone called while GSMBUSY was set to 1? It would be also good. After GPRS session is finished I would just check if someone called meanwhile.Thanks in advance.

author: helius
author_rank: Super Contributor
timestamp: July 05, 2017, 11:20:12 am
content: ATQ1 disables all status and result codes from the modem, including +RING.They can be re-enabled via ATQ0.

author: Kemme
author_rank: Contributor
timestamp: July 05, 2017, 02:08:21 pm
content: Is it possible to disable +RING only? ATQ1 disables all codes but I need them for my GPRS session. It is +RING which disturbs it.
At my wit's end - Page 1
Forum section: electronics / beginners

author: Epovo
author_rank: Contributor
timestamp: March 27, 2024, 11:31:20 am
content: Sorry, I could not find a descriptive subject line, because I need help with something I don't really understand.I am connecting a device which outputs an audio signal to an amplifier, and then to the speaker. It works fine.Then I wanted to power the device with the same power source of the amplifier (this power source is a set of Li ion batteries). The device powers on ok, and it outputs a nice test sine wave as it should.Butwhen I connect this audio signal to the amplifier, something strange happens. The speaker starts to jump, the power led on the device starts blinking. Eventually the amplifier breaks down (I think this is what broke the amplifier, though I can't be sure).I have installed a brand new amplifier and it behaves the same, although I disconnected it before it broke!In summary, the amplifier works fine, the device works fine and they also work fine togetheras long as they are individually powered.I have attached a diagram to show what I want to do. I can't do much testing for fear of the new amplifier will break too.Any suggestion will be appreciated!

author: brucehoult
author_rank: Super Contributor
timestamp: March 27, 2024, 12:30:16 pm
content: Why do you have two wires from audio device to amplifier?Perhaps you should try AC coupling them e.g. via idk maybe a 5 or 10 uF capacitor followed by a 10k resistor to gnd?

author: Epovo
author_rank: Contributor
timestamp: March 27, 2024, 12:34:43 pm
content: the two wires are the two wires from a mono jack connector: signal and ground.I will do as you suggest - would you do the AC coupling on both?

author: bateau020
author_rank: Frequent Contributor
timestamp: March 27, 2024, 12:49:58 pm
content: Indeed, AC coupling is probably the solution. AC coupling only the signal wire, and NOT connecting the ground to the audio source, could be OK. If the sound quality is bad, some more measurements and probably more photos would be needed.

author: pcprogrammer
author_rank: Super Contributor
timestamp: March 27, 2024, 12:58:00 pm
content: There is a good change the amplifier makes a virtual ground and when you connect both devices to the same battery and then connect the signal ground to the virtual ground of the amplifier things go wrong.In this case an AC coupling won't help. Try not connecting the signal ground to see what happens.

author: PA0PBZ
author_rank: Super Contributor
timestamp: March 27, 2024, 01:08:00 pm
content: The TPA3110 datasheet gives you the answer:

author: Epovo
author_rank: Contributor
timestamp: March 27, 2024, 06:58:40 pm
content: Thank you guys!Both solutions (not connecting the signal ground and the AC coupling) worked fine.You guys are wonderful.
at the equivilent watt rating, what components last the longest - Page 1
Forum section: electronics / beginners

author: krayvonk
author_rank: Regular Contributor
timestamp: July 10, 2019, 02:21:36 pm
content: Out of a diode, resistor and capacitor, what is the order of constitution and less thermal problems?

author: ArthurDent
author_rank: Super Contributor
timestamp: July 10, 2019, 02:29:35 pm
content: The answer is: a wire

author: ArthurDent
author_rank: Super Contributor
timestamp: July 10, 2019, 03:52:36 pm
content: Nice word salad. From what I recall the flux capacitor has to be cooled with liquid nitrogen. At absolute zero there are no losses.

author: krayvonk
author_rank: Regular Contributor
timestamp: July 10, 2019, 04:01:31 pm
content: I worked out that esr has larger resistance than r, because e and s are large values?

author: Zero999
author_rank: Super Contributor
timestamp: July 10, 2019, 04:55:27 pm
content: All components heat up, even wire, who's current rating is determined by the acceptable temperature rise of the insulation and the conductor's resistance, therefore power dissipation.
AT27C1024 read on a TL866CS - Page 1
Forum section: electronics / beginners

author: lolsteve98
author_rank: Newbie
timestamp: September 20, 2018, 11:30:39 am
content: Hello all,Thank you for having me in your forumI'm currently trying to replace an EPRPOM (AT27C1024). The chip is off the board and I'm working to get a read from it using a PLCC44 to DIP40 adaptor on my TL866CS (Minipro) . However I'm getting inconsistent reads of the chip.I've tried moving the adaptor about in the DIP socket to see if it's a connection issue and also applied pressure to the top of the chip during read to check it's making sufficient contact but alas the problem still occurs.Any advice for getting a consistent result?

author: keymaster
author_rank: Regular Contributor
timestamp: September 20, 2018, 01:36:59 pm
content: try to freeze it or heat it , which ever work best . (my bet is on freeze) .if you do not have a freeze spray, try normal air spray upside down.

author: bson
author_rank: Unknown
timestamp: September 20, 2018, 10:08:07 pm
content: And if freeze spray does work, try a contact cleaner - both on chip pins and the PLCC socket. (Use a swab, don't soak the socket.) Like DeOxit.