hybridfree/eevblog-posts huggingface dataset:
Testing two outputs with one electronic load? - Page 1
Forum section: electronics / beginners

author: jwhitmore
author_rank: Regular Contributor
timestamp: September 17, 2018, 11:25:56 am
content: I've a uC controlling two 12V outputs that I'd like to test, but I've only got one electronic load. The obvious solution is to simply buy another electronic load, but for the moment, as a thought experiment, I was trying to think of a simple solution. Both 12V DC outputs are being switched from the same voltage source, so can be connected in parallel to give the same 12V output but the currents summed. So if both outputs are connected to the electronic load, which is measuring 10Amps then the sum of both outputs is giving 10Amps. Assuming both channels are more or less identical.If I wanted to independently test the two output channels, A & B: say taking 1Amp from both but then stepping up channel A from 1A to 2A, 3A, 4A and finally 5A. So now 6Amps would be going to the electronic load. Then step up Channel B's output from 1A to 5A so 10Amps is being burned off in the electronic load.I can't think of a way to do this, sort of having two independent electronic loads. That doesn't mean there isn't a way, it just means I can't think of one. There is an eevblog video on setting the current output with a FET but that FET would be getting hot burning off the power rather then my present electronic load.

author: ogden
author_rank: Super Contributor
timestamp: September 17, 2018, 11:37:52 am
content: Quote from: jwhitmore on September 17, 2018, 11:25:56 amMost of voltage regulators do not like paralleled outputs. Even if both regulators are stable - slightest voltage regulationdifferenceerror will put most of the load on one regulator only.As you have quite popular 12V voltage, you can use 12V light bulb(s) as load on 2nd channel. Just two cents.
Texas instruments bridge circuit - Page 1
Forum section: electronics / beginners

author: nForce
author_rank: Frequent Contributor
timestamp: January 18, 2019, 08:25:49 pm
content: I would like to know, why do we use:http://www.ti.com/tool/BOOSTXL-DRV8305EVMWhat is the functionality, purpose? (Because I don't understand that what is written in the datasheet).Thanks.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: January 18, 2019, 09:06:56 pm
content: What about it?The link is to an evaluation module; we use these to, well, evaluate the ICs in a manufacturer-recommended circuit.If you meant something else, could you be specific?Tim

author: nForce
author_rank: Frequent Contributor
timestamp: January 18, 2019, 09:57:23 pm
content: No, I meant the three-phase driver. So this is some sort of frequency converter for driving induction motors?

author: halexa
author_rank: Regular Contributor
timestamp: January 18, 2019, 10:10:32 pm
content: If you read the datasheet for the DRV8305 IC it says:Applications• Three-Phase BLDC and PMSM Motors• CPAP and Pumps• Robotics and RC Toys• Power Tools• Industrial AutomationSo basically a brush-less DC motor gate driver
Text or graphics onto metal project enclosure faceplate - Page 1
Forum section: electronics / beginners

author: Dipski
author_rank: Contributor
timestamp: January 02, 2014, 10:18:25 am
content: Hi guys, just a quick one - whenever I look at projects in the electronics magazines many of them have text, color or graphics on the metal faceplate of the enclosure. I thought hey that would be great to have on my project but I can't seem to find out how it's done, can anyone help?

author: andtfoot
author_rank: Unknown
timestamp: January 02, 2014, 10:24:43 am
content: There are a few ideas here:https://www.eevblog.com/forum/projects/custom-logo%27s-(etc)-on-a-metal-enclosure/If I can't engrave it with my CNC router, I normally print out stuff on transparency paper and glue it on.Edit: I also have alabel printerthat I use if it's a personal project that requires more function than form.

author: Dipski
author_rank: Contributor
timestamp: January 02, 2014, 10:59:47 am
content: Thanks for the quick reply! Etching looks amazing, but the label printer does look good and easy enough to do.Is the transparency paper you use the same type of material they use for overhead projector transparencies, the thick-ish clear plastic sheet you can print on with a laser printer?

author: andtfoot
author_rank: Unknown
timestamp: January 02, 2014, 11:08:44 am
content: Quote from: Dipski on January 02, 2014, 10:59:47 amYep, that's the one. I print it flipped and place it back-to-front so I get a glossy surface on the outside.

author: robrenz
author_rank: Super Contributor
timestamp: January 02, 2014, 12:26:00 pm
content: This video covers making the graphic overlay on this meter. Be patient it gets to the overlay part.This video covers getting a sticky graphic on without getting into trouble

author: ovnr
author_rank: Frequent Contributor
timestamp: January 02, 2014, 12:52:14 pm
content: Only partially related, but wanted to put it here anyway:If you need a durable surface that'll withstand a fair bit of abuse (think touch controls, etc), I've had fairly good luck with printing a reversed image onto a transparency sheet (laser printer), then spraypainting the back with white - or whatever background color you'd like - paint. This puts the entire thickness of the transparency sheet between the hostile outside world and your text, as opposed to surface-printed text. If your printer gives even results, you can even do inverted colors (black background and white/colored text). You can also add clear areas for displays and LEDs by masking the sheet before painting it.Then just stick it on with a thin double-sided tape. I quite like 3M's adhesive transfer tapes (narrow rollsheet- this is 60µM stuff, they also make thicker 130µM tapes that also work well for rougher surfaces).
Text to speech/ Port from Raspberry Pi to new processor - Page 1
Forum section: electronics / beginners

author: Vindhyachal.takniki
author_rank: Frequent Contributor
timestamp: September 23, 2016, 01:17:56 pm
content: 1. I have a made a code on raspberry pi which takes images from raspberry pi camera and do image processing and convert text into speech. code is working. On raspberry pi I have used its pi camera & audio jack only. Code is written in python. Now I want to modify the product as size of raspberry pi is large & consumption is high. Pi zero is not avaible in large quantity.2. Which low power processor I should use to modify the size of board and control curent consumption of product also so that it can run on battery also.3. Or should I port code on microcontroller? One problem in this case I have used python for programming & code uses libs like pytesseract, ocr, numpy. In microcontroller how do I port this code? Also camera interfaced is pi camera whose drivers are pre written on pi & audio drivers also.

author: rob77
author_rank: Super Contributor
timestamp: September 23, 2016, 01:30:38 pm
content: you have basically few options :1. go for a different system-on-chip with linux + python running (low power small systems with linux are next to non-existent).2. switch to a powerful arm based micro and write all the software in C3. try a micro controller with micropython interpreter available, but i doubt you will find all the features you need in micropython.

author: rstofer
author_rank: Super Contributor
timestamp: September 23, 2016, 06:03:49 pm
content: There are other PI clones but I don't know how they compare in terms of power consumptiion. There is still a speed/power ratio and more speed takes more power.Porting thousands and thousands of lines of code doesn't seem like an interesting project. And at some point, it gets down to device drivers and those are hardware specific.There are other small boards that support Linux but they may be missing important interfaces (like the camera):https://store.gumstix.com/coms/overo-coms.htmlThe Orange PI seems pretty interesting:http://www.orangepi.org/You can also Google for 'low power raspberry pi' and find techniques for minimizing power consumption. Nothing magic, just sleep when not in use.
tft display receiving corrupted data - Page 1
Forum section: electronics / beginners

author: ClemensU42
author_rank: Newbie
timestamp: November 27, 2021, 07:57:37 am
content: Hi everybody!I'm quite new to electronics and already have done some small projects but now I wanted to make something bigger and decided I want to create my own calculator. As a display I use a tft display and as controller I use a atmega328p and atmega32 chip.Now my problem is that the display is working perfectly fine on a arduino uno but when using it on a perfboard the data the display is getting, is corrupted and it resets all of the time. The connections are all correct, as sometimes the display shows the right stuff for a short time before resetting. Could someone tell me what causes these data corruptions and how I can fix it?

author: cemelec
author_rank: Contributor
timestamp: November 27, 2021, 10:10:08 am
content: If you can exclude incorrect wiring (easy to do on perfboard) the most likely problem is stray capacitance and marginal timing. E.g. CS (chip select) or R/W (read write) among others need to be stable before attempting data read or write. Have you tried lower frequency operation?

author: ClemensU42
author_rank: Newbie
timestamp: November 27, 2021, 10:39:58 am
content: I've now tried it with a lower frequency now and it works, thanks!If I understand correctly, it's most likely that stray capacitance messes with the clock signal. Is there a way to reduce it on perfboard or can I only get mostly rid of it on a custom pcb?

author: HB9EVI
author_rank: Frequent Contributor
timestamp: November 27, 2021, 11:00:04 am
content: you should give us a little bit more facts.what is the clock speed of the ATmega? what's the clock rate of the SPI? what TFT are you using?

author: cemelec
author_rank: Contributor
timestamp: November 27, 2021, 11:05:37 am
content: You can still get good results with perfboard, a few tips:- Pay attention to grounding, a good solid, short, low impedance ground to all chips or boards, avoid ground loops- plenty of well grounded decoupling capacitors close to power connections + a few more spread around- short connecting leads where possible, avoiding capacitive coupling between leads, connectionsAn online search for e.g. "pcb layout guidelines" will guide you through a lot of the above which apply just as much to perfboard layout as to PCB's
TFT Touch on Arduino - Page 1
Forum section: electronics / beginners

author: Nickk2057
author_rank: Regular Contributor
timestamp: January 12, 2015, 05:00:50 am
content: Alright... so i bought a 2.8" TFT Touch Shield from Seeed Studio. is a v1.0 type. when i get to try to put the stuff on the Arduino it gets this...... I am clueless on this to even find out how to fix this... and i want to use this for my program to use for computer status.any help is appreciated.Thanks,Nickk2057

author: Psi
author_rank: Super Contributor
timestamp: January 12, 2015, 06:06:50 am
content: The compiler doesn't know what type "TouchScreen" is.You'll be missing an #include line that pulls in the library.probably something like.. #include "TouchScreen.h"You need to "have" that library on your PC of course. I believe you get it from the adafruit page.

author: Nickk2057
author_rank: Regular Contributor
timestamp: January 12, 2015, 06:22:58 am
content: it does though.....

author: miguelvp
author_rank: Super Contributor
timestamp: January 12, 2015, 07:50:40 am
content: In this wiki they call the header TouchScreen.hhttp://www.seeedstudio.com/wiki/2.8%27%27_TFT_Touch_Shield_V1.0Code:#include <stdint.h>#include <TouchScreen.h>#include <TFT.h>They do have links to the libraries needed, maybe it's for a different TFT touch shield? not sure.
TGP110 pulse generator. What would I use it for? - Page 1
Forum section: electronics / beginners

author: gb243
author_rank: Contributor
timestamp: April 24, 2016, 06:44:40 pm
content: I am being spammed by adverts after having looked at this unit at distrelec. I can maybe see a use in a physics lab but has it a use in everyday electronics? Maybe measuring the core saturation point of power inductors that requires a pulse train? What else does? I also understand that the case is mostly empty which shows good ergonomic design. A well laid out panel is a massive plus.Good design and a nice case is not enough even if I do have an equipment buying obsession.

author: rstofer
author_rank: Super Contributor
timestamp: April 24, 2016, 07:53:55 pm
content: For my limited electronics purposes, I can get along without it. It would be a nice clock source for some kind of logic project but since I do those with a CPLD or FPGA, I can easily synthesize a pulse generator internally. I kind of expect they just use a CPLD as the basis for the project. At most it would take a really small FPGA.I couldn't see a price at the USA site and I don't get involved with things that require a quotation. All that means is that I will get the price du jour. Everybody on the planet will get a better price than me.
Suspicious TH resistors soldering found in branded device  - Page 1
Forum section: electronics / beginners

author: sasa
author_rank: Regular Contributor
timestamp: August 26, 2017, 09:42:10 am
content: I'm a bit surprised to find this way soldered components in branded PSU (teardown).Res1 - About 2W resistors, soldered quite high. This board was actually attached to heat sink and leads was dangerously near.Res2 - Stocking, low value 2W resistors, with no heat shrink, notable oxidized. No space to solder it otherwise, however concern is omitted heat shrink in order to prevent oxidation and possibly sparks or short.These are in every source unacceptable ways to solder axial TH components, however I may overlook some rational reason for such solution.

author: Rerouter
author_rank: Super Contributor
timestamp: August 26, 2017, 10:00:19 am
content: Where they sit in a schematic would be far more telling, e.g. if they where in parrellel.If they where behind a fuse, and on the mains side of an isolation slot, while its not building for longevity (they dont seem discolored so i would say they may have picked the wattage well) Its not negligent,To me it seems done to manage the power rating well (again, not discoloured), wrapping in heat shrink greatly reduces the effective wattage, Equally the formed leads off the board, that is the norm for hot components, you dont want it damaging the board, The oxidisation looks marginal, I am assuming atleast 1 year old. if you run a resistor hot and the plating reacts with oxygen, it will react.The only way i would take issue with it is if the resistor body to a lead was less than the required isolation gap, that is a no-no.

author: sasa
author_rank: Regular Contributor
timestamp: August 26, 2017, 10:40:16 am
content: Thank you for comment.The first picture resistors are part of doubler voltage board (2x res + 2x caps, 2x diodes, nothing else). I have actually seen the same board in other models of the same manufacturer with resistors normally soldered.The second picture ones, probably limit current resistors (second was near) on 3.3V rail. Unfortunately, I have no actual schematic.

author: Benta
author_rank: Super Contributor
timestamp: August 26, 2017, 05:28:51 pm
content: It's absolutely acceptable, even preferable to do this. It reduces the operating temperature of the resistors, but more important, it reduces thermal and mechanical stress on the solder joints.

author: rsjsouza
author_rank: Super Contributor
timestamp: August 26, 2017, 06:08:09 pm
content: As others have said, components that operate in high temperatures usually benefit from being distanced from the base PCB. This helps with their own thermal dissipation. More often than not I find darkened boards under high power components - especially in single-sided PCBs commonly used in Power Supplies.
TH16B for seconds indicator - Page 1
Forum section: electronics / beginners

author: remak yourohm
author_rank: Newbie
timestamp: August 01, 2020, 06:33:16 pm
content: I don't know how to wire up TH16B, I found a datasheet herewww.russiantubes.combut am not familiar the schematic and how to wire it up to work correctly, I think the pinouts are pin 1=anodepin 2/4= grid pin 3= pulsed pin 5=cathodeImage pinout from right to left pins 1-5. total resistance is 141k with 1mA at a voltage of 160vdc i don't know what to do with pins 2,3,4 thanks for any help

author: wizard69
author_rank: Super Contributor
timestamp: August 02, 2020, 12:42:31 am
content: either my web browser has gone on the blink or your posted picture has been corrupted significantly because it looks like a pixelated mess to me. A better pic might help somebody familiar with this device.

author: floobydust
author_rank: Super Contributor
timestamp: August 03, 2020, 12:07:08 am
content: TH16B is a cold cathode thyratron, used as a simple neon lamp for colons on nixie clocks?I think you have most of it with Pin 5 cathode to GND and Pin 1 anode to B+ through a resistor 100k-1MEG typ. for at most 1mA. I think the other pins can change the glow voltage so you could check it after changing them.Grids pins 2,4 tie to the anode pin 1. Pin 2 might be a screen-grid though, it is on hot cathode thyratrons. I would try it to the anode. I think the firing voltage is affected the most by those two pins.Pin 3 is odd, the tube seems to have a "keep-alive cathode" or "glow pin" it is also called, which is a low current always-on cathode to make the thyratron fire faster. I'd leave it unhooked. Same for TH17A.TH4B (TX4Б) does not have the extra keep-alive cathode. Datasheet is a 1MEG to 220VAC.I believe avoiding"cathode spoiling"to give longest life, it would not matter pin2, 4 connections.
TH6P03T27CL What is this IC?? - Page 1
Forum section: electronics / beginners

author: dav
author_rank: Regular Contributor
timestamp: June 01, 2016, 04:57:46 am
content: I've got 5 of them but I cannot find a datasheet.20 pin DIP and ST branded.Who can help me?

author: dav
author_rank: Regular Contributor
timestamp: June 01, 2016, 05:01:50 pm
content: Pic added

author: sk614
author_rank: Contributor
timestamp: June 02, 2016, 05:28:59 am
content: looks like a transient suppressor diodes. Similar to this TH6P04T25CL

author: dav
author_rank: Regular Contributor
timestamp: June 03, 2016, 01:17:27 pm
content: thank you
thandar tf 200 frecuency meter calibration - Page 1
Forum section: electronics / beginners

author: m3vuv
author_rank: Super Contributor
timestamp: April 03, 2022, 12:35:24 pm
content: Hi all,i have a thandar tf-200 frequency counter,got it from ebay untested,i have measured the cw output from my nanovna with it and it seems fine!,I just wanted to know is there a way to check its calibration?all i have is scopes and a vhf/hf radio and a sig gen without a readout,TIA.

author: TimFox
author_rank: Super Contributor
timestamp: April 03, 2022, 02:26:50 pm
content: Can you adjust your uncalibrated signal generator for "zero-beat" with one of the WWV or other short-wave standard frequencies (e.g., 5 MHz) and measure it with your Thandar?

author: bob91343
author_rank: Super Contributor
timestamp: April 03, 2022, 05:03:23 pm
content: A better way is to beat the master oscillator in the counter against WWV and listen in a receiver. This presumes that the master oscillator is on a WWV frequency.However, I have a cheap counter that uses a 32kHz clock crystal as a master oscillator and this requires a different approach. The sticky part is to create a signal stable enough to calibrate the counter; many signal generators are not up to this task.

author: TimFox
author_rank: Super Contributor
timestamp: April 03, 2022, 05:17:52 pm
content: Another approach is to buy one of the cheap Chinese or used "GPSDO" units on eBay with a 10 MHz output and measure its frequency with the Thandar.Typical price range is $80 to $250 USD.

author: m3vuv
author_rank: Super Contributor
timestamp: April 03, 2022, 07:09:02 pm
content: it only cost me £25 so dont want to spend more than i gave for it on a gps unit,i wanted to use what i have,actualy i have a tadida rikken counter with an 10mhz xtal oven output,may try that.

author: TimFox
author_rank: Super Contributor
timestamp: April 03, 2022, 07:58:52 pm
content: You forgot to mention that other counter. Check the manual to see what the accuracy of the internal frequency standard is: many counters have options for improved performance.If you have nothing else, and your counter can measure a large number of periods ("Period Average" mode), you can always check against the 50/60 Hz local power line, using a low-voltage transformer for safety.

author: bob91343
author_rank: Super Contributor
timestamp: April 04, 2022, 01:11:56 am
content: The easy way is to take that 10 MHz from the good counter and listen to its beat with WWV at 10 MHz. Then adjust it for zero. (That's not as trivial as it sounds.) Then the good counter is calibrated and can serve as a reference for the other one.

author: tanveerriaz
author_rank: Contributor
timestamp: April 04, 2022, 03:48:05 am
content: if you have Ublox Neo-7M. 10 MHz output from the Ubloxhttps://4.bp.blogspot.com/-Aq0R8LUMPGY/VhARSwkSIPI/AAAAAAAADo8/N7SJG3_YUZs/s400/JustGoodEnough.jpghttps://www.qsl.net/pa2ohh/17gps.htm
thandar tf200 counter - Page 1
Forum section: electronics / beginners

author: ME
author_rank: Frequent Contributor
timestamp: February 16, 2025, 10:15:41 am
content: My thandar tf200 appears to use a 4Mhz timebase xtal, Can anyone tell me why its not 10Mhz like most?, Also i have a OSC5A2BO from cti, could that be fitted?, thanks.

author: 807
author_rank: Frequent Contributor
timestamp: February 16, 2025, 12:02:21 pm
content: The 4MHz xtal is divided down by 4 internally, so the reference is actually 1MHz. There may not be enough room inside the case for an OCXO. Perhaps divide the OSC5A2BO by 10 & connect to the external reference connector.

author: Terry Bites
author_rank: Super Contributor
timestamp: February 16, 2025, 12:29:47 pm
content: Because it was so very cheap.
Thanks for the add - Page 1
Forum section: electronics / beginners

author: Spark-Doctor
author_rank: Contributor
timestamp: May 02, 2018, 09:41:55 am
content: Hi all. At 50 years young and just getting into electronics in a serious way. Have been a commercial electrician most of my life but needed to find a hobby that gets the brain working. Got permission from the big boss to convert the shed into my new lab. Should be finished this weekend.Ian

author: Electro Detective
author_rank: Super Contributor
timestamp: May 02, 2018, 11:29:32 pm
content: Welcome to the forum, and good luck with the new lab...hopefully the Treasurer can present the budget to the Big Boss without too much... >Lots of sparkie chat pops up here too btw

author: tpowell1830
author_rank: Frequent Contributor
timestamp: May 02, 2018, 11:40:29 pm
content: Quote from: Spark-Doctor on May 02, 2018, 09:41:55 amHi Ian, welcome to the forum. There is a perma-thread for newbies where you can introduce yourself, here:https://www.eevblog.com/forum/chat/new-member-please-introduce-yourself/2425/

author: bitseeker
author_rank: Super Contributor
timestamp: May 02, 2018, 11:50:38 pm
content: Welcome, Ian. Anytime is a good time to get into electronics. All the best on the new lab!
Thanks - Page 1
Forum section: electronics / beginners

author: jgalak
author_rank: Regular Contributor
timestamp: November 27, 2017, 03:15:00 pm
content: Hey, just wanted to say thanks to everyone for the amazing amount of useful info both in the VBlog and on this forum. I've been tinkering with electronics since I was a kid, played with it, off and on, for years, and recently had some projects that required more gear. The info here was invaluable for figuring out where to spend the money on higher-end stuff, and where I could economize on less critical things, without sacrificing too much reliability.Many more questions will most certainly be forthcoming.
The $21 kit oscilloscope - Page 1
Forum section: electronics / beginners

author: Peabody
author_rank: Super Contributor
timestamp: October 23, 2017, 04:17:57 am
content: That would be the JYETech DSO150 "Shell", available now from Banggood for US$21 with free shipping. Plus another $10 to cover a real scope probe (comes with alligator clip probe) and 9V power supply.Dave has made it clear he thinks these are rubbish, preferring instead to buy a used analog scope on Ebay for $50. I disagree about the rubbish, but agree on the analog scope for serious, demanding work. I mean, you even get two channels.But the kit scope can be really handy in those cases where you're dealing with audio frequency stuff - opamps, servos, stepper motors, and don't want to bother getting a big honking analog scope out of the closet for some quick check on something. And some have rigged it for battery operation so they can take it to the field.At my local OSH meetup group, we did a project to let people into the office building as they arrive after hours without someone having to go down two floors to let each one in. It has walkie talkie ring tone audio coming out of a headset jack into a dual opamp, which converts the low-level audio into a rail-to-rail square wave, which is rectified, filtered and delayed via an RC circuit, and as the charge on the capacitor goes above a resistor divider voltage, the second opamp goes high and triggers an arduino, which then controls a servo which waves a pipe cleaner in front of the motion sensor, which unlocks the door. (The sensor is actually there to let people OUT.)I did the opamp stuff, and the kit scope worked perfectly for that. I can see the incoming audio, the square waves, the votage rise on the capacitor, the hard switching output of the second opamp, and the slow drop in capacitor voltage after the ring tone stops. For this kind of stuff, I just don't need a better scope.Here's a short video illustrating how one might use a kit scope - checking PWM waveforms in this case.Well, I just wanted to put this out there in case beginners, or really anyone with a limited need for a "power" scope, might want to play with this one. At the price, there isn't much at risk except your time for putting together the kit. By the way, make sure you get the kit version that has the SMD parts already soldered.But for anything high frequency, or needing dual channels, Dave's analog scope is definitely the way to go.
The Art Of Electronics - Study - My Questions Blog - Page 1
Forum section: electronics / beginners

author: AcousticBruce
author_rank: Contributor
timestamp: April 30, 2013, 09:57:52 pm
content: Welcome to my Art Of Electronics Study Blog. I bought the book and manual and I have to say it is very interesting the way it is being presented so far. Unfortunately it says the book will not get into math too much (thats my fav part) but as far as practicality this is going to be some excellent study!!!Anyway I am going write questions pertaining to this study and I am hope you can join me on my adventure!SO I will start with Thevenin.In the first chapter shortly after voltage dividers it talks about Thevenin's Theorem. I get it: A thevenin circuit is one that matches the same internal resistance and voltage as a original circuit. I am assuming this is good for prototyping?Can you give me some real practical events when this happens. When you use it personally? A good tutorial (that doesnt just show how to do the math, but really shows practical uses)?

author: c4757p
author_rank: Super Contributor
timestamp: April 30, 2013, 10:04:21 pm
content: One common, practical use of Thévenin equivalent circuits is to compute the impedance of a signal coming from a voltage divider. For example, if I want to divide a signal by three and I want the output impedance to be fifty ohms, I can use a voltage divider of 150 and 75, because the Thévenin equivalent impedance of that is 50.

author: w2aew
author_rank: Super Contributor
timestamp: April 30, 2013, 10:51:25 pm
content: This video I did shows a practical application of Thevenin and Superposition to calculate the characteristics of an R2R resistor ladder DAC.

author: AcousticBruce
author_rank: Contributor
timestamp: May 01, 2013, 01:47:16 am
content: Oooo... that might be the only vid of yours I havn't seen. Thanks!Sent from my Galaxy Note 2 using Tapatalk 2

author: DaveW
author_rank: Frequent Contributor
timestamp: May 01, 2013, 12:27:30 pm
content: This circuit I built up for a competition entry. At a high level, all it does is dynamically change it's input so that the Thevenin equivalent circuit is the same as a Peltier device/Solar cell etc...In this case, you are basically ensuring the resistance of the Thevenin equivalent circuit of the power source is exactly the same input resistance of the power conversion circuit. This gives the highest possible efficiency; and it's just Thevenin theory applied!
the art of electronics : switching the high side of a load - Page 1
Forum section: electronics / beginners

author: Camelkos
author_rank: Newbie
timestamp: June 02, 2020, 01:00:29 pm
content: Hi everybody;i'm stuck at the circuit attached below, can someone please tell me why the collector current is 4,4 as highlighted thank you all.

author: greenpossum
author_rank: Frequent Contributor
timestamp: June 02, 2020, 01:04:29 pm
content: Upper end of R2 is 14.4V lower end about 0.2V so what is 14.2/3.3k?

author: Wimberleytech
author_rank: Super Contributor
timestamp: June 02, 2020, 01:09:35 pm
content: Quote from: Camelkos on June 02, 2020, 01:00:29 pmIgnoring Vce(sat)

author: Camelkos
author_rank: Newbie
timestamp: June 02, 2020, 01:25:55 pm
content: I see now, thank you very much for your help !!

author: Zero999
author_rank: Super Contributor
timestamp: June 02, 2020, 02:02:34 pm
content: I prefer to put the resistor on the emitter side of the NPN transistor.

author: Camelkos
author_rank: Newbie
timestamp: June 02, 2020, 02:31:41 pm
content: can you please give more details about how thiss ill operate, thank you !!

author: Zero999
author_rank: Super Contributor
timestamp: June 03, 2020, 12:28:30 pm
content: Quote from: Camelkos on June 02, 2020, 02:31:41 pmThe voltage across R2 is equal to the input voltage, minus Tr2's base-emitter voltage. I = V/R, so the current through R2 and therefore Tr2's emitter depends on its value and the input voltage. Assuming the hFEis very high, the current through Tr2's collector, is nearly equal to the emitter current. Most of the current will flow through Tr1's base, turning it on. R1 is just there to speed up the turn-off time.For example.Suppose the load current is 100mA, the input voltage is 5V and we want to drive Tr1 with 5mA, to ensure it saturates.VR2= 5 - VBE= 5 - 0.7 = 4.3VIR2= IB= 5mA = 0.005AR2 = VR2/IR2= 4.3/0.005 = 860R. Use the nearest standard value of 820R.R1 can be 1k, which will lower the base current through Tr1 by around 0.7mA, but that doesn't matter.
The best communication protocol - Page 1
Forum section: electronics / beginners

author: bgsteiner
author_rank: Contributor
timestamp: November 01, 2014, 01:24:16 am
content: For one of my projects in development I need to be able to send data over about 100ft of cat5 cable. I am wondering what protocol I should look into using. Wireless is not an option as it is too unreliable with the space I am working in. My plan is to create a modular HID keyboard so that an adapter will translate signals from a node into key presses so the node needs to be able to send key codes.All help is greatly appreciated!

author: ovnr
author_rank: Frequent Contributor
timestamp: November 01, 2014, 01:35:15 am
content: Assuming you use a microcontroller: RS485 signalling. Just use your MCU's UART (think RS-232), then shove it into a RS-485 driver. Add appropriate termination on the end, and off you go.Of course, pretty much anything goes because it sounds like a fairly low-speed link. It'd probably be fine to just shove TTL signals down the wire, but obviously less robust.

author: Richard Crowley
author_rank: Super Contributor
timestamp: November 01, 2014, 01:37:16 am
content: The OSI model of computer networking is like a 7-layer burrito from Taco Bell.But I think you probably don't need the top 5 layers, and you are asking about layer 2...7. Application6. Presentation5. Session4. Transport3. Network2. Data Link - For an application as you describe, I would use bog-simple asynchronous serial.I would use RS-422 balanced, differential signaling to take advantage of the super-balanced Cat cable.If you need something more sophisticated, consider RS-4851. Physical - You have established that you want to use Cat5 cables, presumably with common RJ-45 connectors.Ref:http://en.wikipedia.org/wiki/OSI_modelhttp://en.wikipedia.org/wiki/Data_link_layerhttp://en.wikipedia.org/wiki/Serial_communicationhttp://en.wikipedia.org/wiki/RS-422http://en.wikipedia.org/wiki/RS-485

author: Smokey
author_rank: Super Contributor
timestamp: November 01, 2014, 08:00:39 pm
content: Quote from: Richard Crowley on November 01, 2014, 01:37:16 am
The Biquadratic filter - Page 1
Forum section: electronics / beginners

author: promach
author_rank: Frequent Contributor
timestamp: July 06, 2018, 02:34:03 pm
content: I am reading an article on biquadratic filter. The article is attached in this postHow do we derive corner frequency equation (6) on page 2 ?Does it have to do with equation (5) ?

author: JS
author_rank: Frequent Contributor
timestamp: July 06, 2018, 09:54:39 pm
content: Make the |H(jw)|=-3dB or (6)=0.5, which is the same. Find for which frequencies that's true, build (6) from there.Algebra can be quite confussing for this things, mostly because is not that you are after an answer but the shape of the equation, to be easy to read, so some variable manipulation is needed, not just moving around stuff.JS

author: The Electrician
author_rank: Frequent Contributor
timestamp: July 06, 2018, 11:37:52 pm
content: Set the right side of (5) equal to .5 and solve for omega:
The book with EE interview questions? - Page 1
Forum section: electronics / beginners

author: Obin
author_rank: Contributor
timestamp: March 03, 2016, 09:46:10 am
content: Hi guys,I'm graduating soon and I have a few electronic design engineering and hardware engineering interviews coming up, obviously I want to be well prepared!I recall Dave talking about a book with EE interview questions in one (or two) of his videos, he was pretty fond of it. But i can't find the title anywhere now? I think it was in a mailbag video. I scrolled through all the video's but I didn't see it in any video icon or title.All I know is that it was a while ago (like a year). Does anybody know the book i'm searching for?I also didn't see it in the books list on the eevblog wiki.Thanks!

author: Jbliss
author_rank: Regular Contributor
timestamp: March 03, 2016, 10:13:32 am
content: The Art Of Electronics By Paul Horowitz And Winfield Hill (2015, Dave is always talking about it don't known if its the one you are looking for

author: EEVblog
author_rank: Unknown
timestamp: March 03, 2016, 10:32:05 am
content: Don't recall mentioning that.

author: Obin
author_rank: Contributor
timestamp: March 03, 2016, 12:00:00 pm
content: Quote from: EEVblog on March 03, 2016, 10:32:05 amHmmm maybe i saw it on another channel then, or i dreamt itNo problem, i'll look for it some more and post it when i find it(And no it wasnt AoE)

author: DenzilPenberthy
author_rank: Frequent Contributor
timestamp: March 03, 2016, 03:50:42 pm
content: 'Making Embedded Systems' has interview questions at the end of each chapter but that's more focused towards embedded systems that straight EE, obviously.

author: Ampere
author_rank: Regular Contributor
timestamp: March 03, 2016, 06:48:52 pm
content: Quote from: DenzilPenberthy on March 03, 2016, 03:50:42 pmI recall this being mentioned on The Amp Hour. Maybe that's what OP was thinking of.

author: w2aew
author_rank: Super Contributor
timestamp: March 03, 2016, 11:55:51 pm
content: "The Art and Science of Analog Circuit Design", edited by Jim Williams. Chapter 13. A New Graduate's Guide to the Analog Interview, written by Robert Reay.

author: tggzzz
author_rank: Super Contributor
timestamp: March 04, 2016, 12:27:25 am
content: The best, most revealing, interview question is "tell me about one of your personal projects, why you chose it, what you learned and what you would do differently next time" .I don't think you will find the answer to that in any book.
The cheapest/simplest possible ESR checker? - Page 1
Forum section: electronics / beginners

author: HardBoot
author_rank: Regular Contributor
timestamp: January 11, 2013, 07:02:33 pm
content: No needing an oscilloscope, multimeter, microcontroller, analogue meters cost a lot, so let's skip those too.Smallest possible variety of parts, smallest part count possible, nothing more than a couple cents preferably.I'm thinking, a very low duty cycle oscillator and some voltage comparators driving LEDs with dip switches for range selection.Thinking, perhaps a breakdown pulser, or just a 555 that dumps a very low esr cap array. On the downside of the short pulse you then look at the voltage of the cap with led indicators, the higher, the lower the esr.
The  component JT3028 is equivalent to SG6841  ? - Page 1
Forum section: electronics / beginners

author: eletmoraes
author_rank: Newbie
timestamp: April 28, 2020, 11:47:55 pm
content: I have a source of an amplified box that the JT3028 cracked the top of the component making it impossible to identify it. Researching the possible layout of the device, I believe that the integrated smd is the JT3028. As I couldn't find the integrated to buy, I wanted to see if I can put the SG6841 in place of the JT3028?
The Joo Janta Peril Sensitive Staircase. - Page 1
Forum section: electronics / beginners

author: BJ
author_rank: Newbie
timestamp: October 08, 2016, 03:11:25 am
content: This is an older thought I had when reading about meta-materials with a negative refractive index.Someone, sooner or later, is going to come up with a coating which will essentially render glass invisible in air (in much the same manner that it is in fact invisible in glycerine, and plexiglass is invisible in water, (that's how a magician walks on water IFYDKB)). And about five minutes later an architect is going to design an invisible staircase or skybridge out of it. Then five seconds after it's installed, one of the builders will be on his back beneath it contemplating visions of lace and elastic and maybe even a little less.Sooo. Joo Janta. For two reasons. One, the practical, as they are being climbed, have the steps ahead, beneath and behind darken, cloud or light up beneath the climber's feet. And two, the aforementioned Donny boy Trump under the skybridge.
The last word - Page 1
Forum section: electronics / beginners

author: Unknown
author_rank: Unknown
timestamp: July 22, 2013, 07:45:02 am
content: In my time I've never a more up your own bunch of people ever, hope you all having get togethers showing each other your 50,000 count meters as I sure you get off on that subject , a word of advice there is a real world out there, and before you all get together you really should smell under your armpits , and take a shower.

author: Simon
author_rank: Unknown
timestamp: July 22, 2013, 07:57:23 am
content: Well you saved me the effort of locking the topic and you have been given a 60 day cooling off period (30 of which is for your email address)
The magic Smoke out of a component - Page 1
Forum section: electronics / beginners

author: dan3460
author_rank: Frequent Contributor
timestamp: October 08, 2015, 06:21:40 pm
content: This is the third time that I have build a two rail power supply and like an idiot put the lytic caps with the negative side to ground in the negative rail.I bring the power supply up using a variac, to make sure that I don't have a short, or smell. Get it to full power and then ....."Bang" and some times "Bang bang bang", the magic smoke is gone, i'm having a heart attack because at that moment I was testing the voltages from the supply.I always tell the kids that teach to check and recheck cables and components, to make sure that polarities are correct and there is no shorts.

author: German_EE
author_rank: Super Contributor
timestamp: October 08, 2015, 07:03:33 pm
content: Yes, they do fail rather well. I remember plugging a control PCB into an elevator cabinet and one cap was the wrong way around. There was a loud bang and it shot across the room trailing its foil behind it. Fun times.

author: JoeN
author_rank: Frequent Contributor
timestamp: October 08, 2015, 10:50:37 pm
content: I use a lab power supply that tells you how much current your circuit is using in mA. It's pretty obvious that if your circuit that contains a low power microcontroller and a few other chips and should consume maybe 20mA is consuming 100mA, and that figure is rising, there is something seriously wrong, like what you are talking about. That is what you will see, current way too high and rising, a rather obvious telltale sign. Get a supply like that. It's reassuring to be able to look at it any time you want to see how much current the board is eating.

author: Deathwish
author_rank: Unknown
timestamp: October 08, 2015, 11:13:51 pm
content: any chance of a pic of the top and bottom of the board ?

author: Cubdriver
author_rank: Unknown
timestamp: October 09, 2015, 02:31:32 am
content: Yikes!! Yeah, electrolytics don't like being reverse biased and will let you know of their displeasure in no uncertain terms!That must have been a heart pausing moment (or four). Hopefully they didn't make too much of a mess, and you have some spares without needing to order more. My guess is that this is now an error you won't repeat any time soon - it seems once something like this happens you get a lot more neurotic about making sure the caps are connected correctly.-Pat

author: dan3460
author_rank: Frequent Contributor
timestamp: October 09, 2015, 12:27:44 pm
content: Quote from: Deathwish on October 08, 2015, 11:13:51 pmI don't have any of the ones I built anymore, but I have the test board (which was the first one to have caps backwards) on my bench. Will take a picture and post.
The MIC5501/2/3/4 is not suitable for RF transmitter systems. - Page 1
Forum section: electronics / beginners

author: oddzod
author_rank: Newbie
timestamp: April 27, 2023, 02:40:42 am
content: Why?I found this when looking a the datasheet for the MIC5504. Section 4.0 on page 10. The datasheet doesn't elaborate on this any further. It doesn't matter for my application, but it piqued my interest.https://ww1.microchip.com/downloads/en/DeviceDoc/MIC5501-02-03-04-300mA-Single-Output-LDO-in-Small-Packages-DS20006006B.pdfEdit: Figured I'd elaborate on my theories. Maybe it has something to do with load regulation. RF transmitters would require current spike at high frequencies that would cause the regulator to oscillate. But wouldn't an MCU operating at a similar clock rate cause the same thing? But then again maybe they are betting that if your using a processor operating at a few hundred mHz or more, that your not using a small linear regulator...

author: ataradov
author_rank: Super Contributor
timestamp: April 27, 2023, 03:09:09 am
content: This was added in 2019 via a PCN, so it was a later addition.I doubt it is related to the load regulation. It is probably directly RF sensitive. It does not say that it can't power the transmitter, so likely using it on the board next to the transmitter is also problematic.Those late notes are always vague. It is possible that someone tried to use it right next to 1 kW transmitter and it somehow misbehaved. I'd expect any reasonable Wi-Fi like applications to be fine.

author: Kim Christensen
author_rank: Super Contributor
timestamp: April 27, 2023, 03:20:07 am
content: Seems like an asinine statement on their part considering that they list smartphones under applications!Quote

author: ataradov
author_rank: Super Contributor
timestamp: April 27, 2023, 03:24:16 am
content: Here is how it goes. The datasheet gets published. Big and important customer finds an issue in their specific application. They are in the industry where changes on their side must be justified by the changes on the vendor side. A PCN gets published, customer uses that to start internal process.Nobody really wants to put confusing statements for marginal use cases, but you have to. So, they do absolute minimum of the editing. Realistically, if smartphone vendor really wants that IC, they will ask their field support to check what that note actually means and if that applies to their case.

author: oddzod
author_rank: Newbie
timestamp: April 27, 2023, 03:37:39 am
content: Much thanks.The explanation that a customer had an issue, so they had to add that line to the documentation makes sense. I've seen it my self, in my own industry. I just wanted to make sure that I wasn't missing something fundamental about RF.
The output of Op-Amp[LM324] has error as non-inverting Amp - Page 1
Forum section: electronics / beginners

author: booboo1
author_rank: Newbie
timestamp: April 25, 2015, 02:19:53 pm
content: Hi everybodyI'm a newbie and working on LM324 to learn Op-Amp. this is my circuit:One of the resistors is 217ohm and another 978ohm. then the gain should be 4.50691 as you can see. so far so good. I know this is for ideal Op-Amp. I applied 0.15v to the input and got 0.94v in the output. then the gain is 6.26667. again I applied 0.35v to the input and got 2.03v then gain should be 5.8!?o_Oagain I applied 1.86v and got 10.31 then the gain is 5.54301! holy crap!why isn't the gain stable? because of input offset voltage? How can I stabilize it?

author: mikerj
author_rank: Super Contributor
timestamp: April 25, 2015, 02:34:27 pm
content: The gain of that circuit is 1+(978/217) = 5.5. The errors in your measured gains are likely to due to a combination of input offset voltages and output swing limitations of the LM324

author: PSR B1257
author_rank: Frequent Contributor
timestamp: April 25, 2015, 03:45:18 pm
content: Quote10.3V is about the maximum the LM324 can deliver it's output with 12.xxV supply voltage due to saturation.One advantage of the LM324 you have already discovert, it can take an input signal close to GND. But too close and you might get in trouble.If you measure a little more ponits, you end up with a graph like this.As you can see, it is fairly linear, besides from the top and bottom end so to speak. But that's all you can expect from a LM324 anyway.
the output voltage of an amplifier ? - Page 1
Forum section: electronics / beginners

author: harrysmith
author_rank: Contributor
timestamp: October 10, 2020, 10:11:30 am
content: Hello everyone. someone can know what it is the equation of Vout. thanks

author: mikerj
author_rank: Super Contributor
timestamp: October 10, 2020, 12:38:22 pm
content: -Vo = V1(R3/R1) + V2(R3/R2)

author: MasterT
author_rank: Frequent Contributor
timestamp: October 10, 2020, 12:58:26 pm
content: https://electronics.stackexchange.com/questions/187067/summing-two-voltages-without-the-use-of-an-operational-amplifier
The RX MCU Design Contest is true - Page 1
Forum section: electronics / beginners

author: SuperMiguel
author_rank: Regular Contributor
timestamp: November 24, 2010, 06:34:39 pm
content: So few weeks ago i went tohttp://renesasrulz.com/community/rx-contest,and laugh about it and register thinking that it was a joke. and guess what i got the the board and the book today!!!!

author: DavidDLC
author_rank: Frequent Contributor
timestamp: November 24, 2010, 07:58:33 pm
content: I'm going to receive mine pretty soon as well.I'm going to start working on the project I registered, but I'm wondering what will happen if I don't finish it on time for several reasons.Am I need to return the board ?I didn't find anything on the contest rules about this, well I just made a quick read.

author: EEVblog
author_rank: Unknown
timestamp: November 24, 2010, 08:37:20 pm
content: I'm pretty sure you don't have to return the board.It's a write-off for them. They know that X amount of people are not going to go through and send in a finished entry.Dave.

author: EEVblog
author_rank: Unknown
timestamp: March 17, 2011, 02:53:42 am
content: For those interested in the Renesas RX design contest, get your entries in before the end of March!With only 12 entries so far, your chances of winning are pretty darn good!http://www.renesasrulz.com/community/rx-contest/entry?view=documentsDave.