hybridfree/eevblog-posts huggingface dataset:
UART receiver to parallel out - Page 1
Forum section: electronics / projects

author: Electrole
author_rank: Contributor
timestamp: October 04, 2020, 09:09:54 am
content: I have been doing some search on the Internet to find out how to decode a serial asynchronous (UART) line and output a number of static lines, like 4 or 8, for controlling settings, relays, etc. The idea is to have a simple control mechanism equally suited for communication through a wire and through an optical fibre. Ideally, I would like a solution where the decoder circuitry turns silent when the decoding is done in order to protect the parts of a design which may be noise sensitive. Without doubt there seems to be a wide range of PIC microcontrollers that could do the job. Some controllers even support a sleep function which can wake up once there is traffic going on. The issue is, however, that I'm a novice when it comes to these microcontrollers, and I find the available information overwhelming: It's difficult to sort out all the features and capabilities of the different controllers, and I'm not ready to make a solid design decision any day soon.Would anyone have experience with implementing a UART receiver with a parallel output you would like to share so that I can be pushed in the right direction?BR

author: Benta
author_rank: Super Contributor
timestamp: October 04, 2020, 09:32:25 am
content: A classic is the 16C550 from TI. But turning silent won't really work. The UART needs a clock to work properly.
UART Synchronization Break Problem On XMC - Page 1
Forum section: electronics / projects

author: petersanch
author_rank: Regular Contributor
timestamp: February 28, 2019, 06:22:56 am
content: Hi All,I'm sending data from PC to XMC1300 micro. The PC sends a synchronization break, sends 10 bytes, waits, and repeats.The XMC is programmed to run calculations on the data after 10 bytes are received and the break is used to detect start of new data.Problem is this only works when the delay between previous 10 bytes and synchronization break is 110 ms or more.The frames come in with errors when delay is less than 110 ms, and I need this delay to be shorter.PSR value after a failed frame is 0x4EB7. Break detected, receiver noise detected, stop bit error, busy, data lost.But, if the poll for synchronization break is removed and data is continuously sent without breaks or delays, it all works.I need the break for future development however.Baud rate 9600, synchronization break duration is 2 ms, 8 bit data, 1 bit stop, no parity, no interrupts.Has some body seen this before? Does it have something to do with how USIC implements the synchronization break?Cheers
UART to ETHERNET module with support for 802.1x - Page 1
Forum section: electronics / projects

author: Rigolon
author_rank: Regular Contributor
timestamp: November 14, 2024, 12:12:04 pm
content: Hey guys,I'm looking for a module to convert UART to ETHERNET for a project. But it needs to support IEEE 802.1x.I've found the XPORT EDGE from LANTRONIX, but it's about US$50.I've used before the USR-TCP232-T2 from USRIOT, which was about US$12, but it doesn't support 802.1x.Does anyone know any alternatives?Thx in advance
UART to USB configuration - Page 1
Forum section: electronics / projects

author: Retired2
author_rank: Contributor
timestamp: January 27, 2024, 09:56:00 pm
content: I need some input on how to configure a FT232RL RS232 to USB IC. What I am doing is taking the photodiode output from a DE5000 LCR meter to a 74LS14 Schmitt trigger then to the input TXD pin 1 of the FT232.I jumpered the RTS/CTS line. I have no output on USBDP pin 15 and USBDM pin 16. I disconnected RTS/CTS and jumpered DTS/CTS still no output.My question should I set DTS or CTS to a specific logic H/L and leave RTS/CTS line jumpered.What are suggestions that I could do. Thank you very much

author: berke
author_rank: Frequent Contributor
timestamp: January 27, 2024, 10:35:44 pm
content: Quote from: Retired2 on January 27, 2024, 09:56:00 pmPin 1 is an output (data transmitted from FT232) you should be using pin 5 (RXD).

author: Retired2
author_rank: Contributor
timestamp: January 27, 2024, 11:56:26 pm
content: My apologies,It is wired to Pin 5 RX. I did a typo.

author: moffy
author_rank: Super Contributor
timestamp: January 28, 2024, 05:42:44 am
content: Have you tried both polarities and are you getting a clean RS-232 signal? You might want to look at:https://tltb.slur97.org/ir-to-usb-adapter-for-der-ee-de-5000-lcr-meter/
Uart Wifi Module Quetion! - Page 1
Forum section: electronics / projects

author: diegoterc3
author_rank: Regular Contributor
timestamp: October 31, 2013, 05:07:05 pm
content: Hello! I am buying this to build some circuits with wifi:http://www.ebay.com/itm/281145549555Now what comes in my mind first is:Whats the distance that this wifi can opperate? It says that the output power is 18±2 dBm, but how can I calculate the total lenght from this information?Thank you

author: Whales
author_rank: Super Contributor
timestamp: November 01, 2013, 12:48:06 am
content: I don't think it is feasible to calculate this. One of the biggest factors is your environment: wifi hates walls, but loves line-of-sight. Unfortunately your best bet is to try it out, and then make improvements if it does not work.If you are using fixed locations for your transceivers, then you can use reflectors/directional antennae to focus signals forverylong distances (think in km, assuming no obstacles). This is not as hard or as expensive as you think -- cheap wire cookware does the trick! Checkouthttp://www.usbwifi.orconhosting.net.nz/(it's called wi-fry)

author: diegoterc3
author_rank: Regular Contributor
timestamp: November 03, 2013, 02:53:01 am
content: Yes I understand it is very dependant on the environment and I plan to use it inside a copper mine, but for callibration and testing porpuses I want to use it in an open environment.So I would like to know how long is the range of the module. This way I can know if this will even work or if I have to choose a different module. Does anyone know how to calculate this in a free environment?Thank yo
UART/Ethernet Communication with IC DP83848-EP - Page 1
Forum section: electronics / projects

author: mechorican
author_rank: Newbie
timestamp: January 10, 2024, 03:21:07 pm
content: Hello everyone,I have a question about the IC DP83848-EP. I am unsure about the data sheet. Is it possible with this IC to implement an interface between UART (RX, TX) and Ethernet? For example for communication with an Arduino Mega?

author: ataradov
author_rank: Super Contributor
timestamp: January 10, 2024, 03:55:33 pm
content: What makes you think it would be possible?This looks like a typical Ethernet PHY. The only thing you can do is attach it to an MCU with a MAC. And after that you can make firmware that will do UART to Ethernet translation. But you can't do that with Arduino.The most common off the shelf solution for what you want are modules from Lantronix. Thishttps://www.lantronix.com/products/xport/and other similar modules.

author: mechorican
author_rank: Newbie
timestamp: January 10, 2024, 04:58:07 pm
content: Thank you very much for your help, ataradov.

author: fchk
author_rank: Frequent Contributor
timestamp: January 12, 2024, 01:54:12 pm
content: Quote from: mechorican on January 10, 2024, 03:21:07 pmThis PHY converts Ethernet MII to Ethernet Twisted Pair.You need this:https://www.wiznet.io/product-item/wiz750sr-105/
uBeam's Problems with Efficiency, Practicality and Cost Makes Experts Skeptical - Page 1
Forum section: electronics / projects

author: jazon
author_rank: Newbie
timestamp: November 08, 2015, 03:08:00 pm
content: Skeptics Zap Wireless ChargingSome question if uBeam's wireless charging system is just hot air.Meredith Perry has bold ideas.For starters, there’s her notion to replace intercity car commuting with rides on small personal blimps. Then there’s her idea to mix shampoo with a material used to waterproof electronics, so that you don’t need an umbrella when it rains.But perhaps the boldest – and most controversial – is Perry’s attempt to wirelessly charge electronics, such as cellphones, using ultrasonic waves sent through the air.That idea is being tackled by the 26-year-old’s Santa Monica startup, uBeam Inc., which has raised millions in funding from a number of big-time venture capitalists, including Menlo Park’s Andreesen Horowitz, Santa Monica’s Upfront Ventures, Peter Thiel’s Founder’s Fund as well as billionaire Mark Cuban and Yahoo Inc. Chief Executive Marissa Mayer.However, despite being lauded as the next big thing in energy technology, the feasibility of uBeam’s plan is increasingly plagued by skepticism... [Full story in link below](Basically, physicists, electrical engineers, mechanical engineers and ultrasonic researchers say it's rudimentarily possible, but probably not nearly as efficient, practical or cost effective as uBeam claims.)http://www.labusinessjournal.com/news/2015/nov/08/skeptics-zap-wireless-charging/
Ublox GPS with erroneous 1pps insertion - Page 1
Forum section: electronics / projects

author: 0xFFF0
author_rank: Regular Contributor
timestamp: September 09, 2021, 12:15:05 pm
content: Many people assume that GPS receivers emit a precise second pulse. But that's not always the case. If you examine the pulses more closely, you will find that there are some false pulses among them. The log example shows an Ublox Neo-7M with a false pulse, which was incorrectly inserted after 222 msec. These occur about 0..5 times an hour. Have you ever noticed that too?...sec: 35.004 pps: 3037sec: 36.005 pps: 3038sec: 36.227 pps: 3039 <--- erroneous 1pps insertion after 222 msecsec: 37.005 pps: 3040sec: 38.005 pps: 3041...

author: radar_macgyver
author_rank: Frequent Contributor
timestamp: September 09, 2021, 02:24:53 pm
content: I use an LEA-6T based GPSDO, and have software that's looking for and logging pulses that are more than 100 ns away from the expected (based on system time) pulse period. These can occur due to sawtooth correction, but are rare. I've never seen anything in the logs indicating such a large offset, though.

author: 0xFFF0
author_rank: Regular Contributor
timestamp: September 09, 2021, 02:29:02 pm
content: This is less of an offset because the next pulse is exact. There's an extra tick in between.

author: MarginallyStable
author_rank: Regular Contributor
timestamp: September 09, 2021, 06:30:44 pm
content: Lets see it on an oscilloscope.

author: engineer_in_shorts
author_rank: Regular Contributor
timestamp: September 09, 2021, 10:06:47 pm
content: As far as I know, many metrology labs avoid GPS based standards. There are too many issues to get a good calculated uncertainty.

author: jmw
author_rank: Frequent Contributor
timestamp: September 09, 2021, 10:31:33 pm
content: You could look at tightening the timing and position lock criteria (in particular look at the DOP and accuracy parameters in the UBX-CFG-NAV5 configuration), and also taking stock of your antenna situation.
UBlox NEO 6 forgets parameters - Page 1
Forum section: electronics / projects

author: Cloud
author_rank: Regular Contributor
timestamp: March 30, 2017, 05:19:53 pm
content: For a project I want to use standalone NEO 6 GPS modul. But after I configure module and than turn it off for some time it forgets what I have instructed him. The timepulse goes always from 1kHz back to 1Hz. What am I doing wrong?

author: voltsandjolts
author_rank: Unknown
timestamp: March 30, 2017, 05:26:17 pm
content: What is the voltage from the coin cell / backup battery?

author: Cloud
author_rank: Regular Contributor
timestamp: March 30, 2017, 09:26:49 pm
content: Will check that tomorrow but the module is brand new (http://www.ebay.com/itm/Ublox-NEO-6M-GPS-Module-Aircraft-Flight-Controller-Arduino-MWC-IMU-APM2-NEW-/221987466355?hash=item33af7bec73:g:LkMAAOSwhOVXdieB)
UBlox NINA-W102 - Page 1
Forum section: electronics / projects

author: NightRider92
author_rank: Contributor
timestamp: July 28, 2025, 12:36:31 pm
content: Hello everyone!I'm trying to make a minimal working example with UBLOX NINA W102 chip.I will use internal WiFi antenna. I just need ability to properly boot it, (re)flash it as neccessary and to reset it and maybe later control GPIO pins."3V3" label is just a KiCad label, power for FTDI and W102 shouldbe drawn from USB.Nothing special,just minimal working example.I attached my project (work in progress) and I would like to ask fellow engineersto review this and help me in case if I did something wrong.Thank You in advance!Additional question:I suppose the W102 comes with the bootloader and I can easily flash it via USB (like ESP32 or Arduino)?Also uploaded PDF because maybe the picture is not clear enough:https://pdf.ac/4hNhyS

author: NightRider92
author_rank: Contributor
timestamp: July 28, 2025, 07:53:42 pm
content: Update: completed schematics (see FIRST POST image)I'm really not sure wheter this would work or not and don't want to waste money on making the PCB, so, could someone with more experience,PLEASE, check the schematics?I want to be able to upload the code via USB so I used FT232RL connected to RX/TX pins of NINA-W102 chip.Also, do I need anything else for auto-resetting on code upload (because FT232RL DTR and RTS pins are connected to RESET_N/SYS_BOOT of NINA-W102)?GPIOs used are GPIO5 and GPIO16 for activating the relay and reading temperature.LM1117T-3.3 is used to convert USB 5VDC to 3V3.Please, anyone willing to help, take a lookThank You!

author: NightRider92
author_rank: Contributor
timestamp: July 29, 2025, 08:07:12 am
content: Is there really nobody to help me?
UC3842/3 Compensation Feedback - Page 1
Forum section: electronics / projects

author: VanitarNordic
author_rank: Frequent Contributor
timestamp: January 09, 2020, 11:28:58 pm
content: Hi,I want to design a Flyback, no problem with the transformer, Clamp .. etc. Now I want to design the feedback circuit using a TL431 and an Optocoupler.1) How to calculate the Feedback component values for the UC3842/3?2) How to regulate several outputs?

author: Yansi
author_rank: Super Contributor
timestamp: January 09, 2020, 11:37:02 pm
content: 1) Not that easy, can be only estimated. See:https://www.ti.com/seclit/ml/slup340/slup340.pdfProper verification methods will either way be needid with real hardware. Additionals tweaks of the compensation will be likely needed.2) You need a transformer with low leakage inductance (at least split the primare in two halfes: and put all other windinggs in between these layers). Too high leakage inductance an the output tracking will get mad.Place the regulation loop on the most critical (or most loaded) output rail.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: January 10, 2020, 03:13:03 am
content: Also, if the output rails are common ground, consider jointly regulating them, that is, taking a weighted sum from several (or all) outputs. This doesn'tfixthe cross-regulation introduced by leakage inductance, but it helps the outputs track an overall average, which improves regulation on average (~equally weighted) loads.Note that negative outputs have to be handled differently, because the TL431 does not have a noninverting input (or it does if you look at it the right way, but therein lies the difference of handling).Tim
UC3843 (etc) soft start diode - Page 1
Forum section: electronics / projects

author: b_force
author_rank: Super Contributor
timestamp: October 09, 2022, 10:29:40 pm
content: So I am working on a little voltage booster project with a UC3843(well, actually it's the TL2843, but they basically work all the same, except for some other details).In some datasheets a little soft start circuit can be found (see attachment).Some of them use a diode with it, some don't.Unfortunately I can't find much information about it.Is this to protect for some kind of state were the base of the transistor would become more positive, or is it just to discharge the capacitor?

author: T3sl4co1l
author_rank: Super Contributor
timestamp: October 09, 2022, 10:34:33 pm
content: Fast reset on power cycle.Tim

author: b_force
author_rank: Super Contributor
timestamp: October 09, 2022, 10:52:29 pm
content: Quote from: T3sl4co1l on October 09, 2022, 10:34:33 pmYeah, so the last one, that's what I thought as well
uc3844 flyback converter startup problem - Page 1
Forum section: electronics / projects

author: electros6
author_rank: Regular Contributor
timestamp: September 04, 2014, 02:41:03 pm
content: Hi guys,I designed a flyback converter using uc3844. when I power up the circuit , the voltage at the Vcc pin swings between the threshold ie approximately between 12 and 16V like a sawtooth waveform. I increase the startup current by reducing the startup resister but result in same. Can somebody figure out the problemattached the schematics herewith

author: bktemp
author_rank: Super Contributor
timestamp: September 04, 2014, 03:12:33 pm
content: Your feedback winding does not produce enough voltage for the uc3844 to keep running. So it stops until the startup resistor recharges the capacitor.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: September 04, 2014, 03:27:21 pm
content: Are you actually running it from 48V, and using the winding schedule specified for the transformer?

author: electros6
author_rank: Regular Contributor
timestamp: September 04, 2014, 04:04:42 pm
content: No, I actually used my own designed transformer for 48V . not the one specified in the datasheet
UCC5304DWVR to mosfet over populated with not neede components help - Page 1
Forum section: electronics / projects

author: john23
author_rank: Frequent Contributor
timestamp: June 30, 2024, 07:41:21 am
content: Hello,I have a circuit shown in the attached photo which basicly shows UCC5304 powering a mosfet using floating voltage.My circuit basicly uses figure 22 of the attached datasheet.I know that they put too much capacitors and i am sure i need the diode structrue.basickly we put capacitors to to stabilise voltage supply and reduce noise.any reccomendation regarding what capacitors to put in the structure?https://www.ti.com/lit/ds/symlink/ucc5304.pdf?ts=1719651132605https://www.mouser.com/datasheet/2/196/Infineon_IRF7821_DataSheet_v01_01_EN-3363012.pdf

author: T3sl4co1l
author_rank: Super Contributor
timestamp: June 30, 2024, 01:10:09 pm
content: First things first -- what are the design goals? V, I ratings? Switching speed / edge rate? Frequency / rep rate? What is the load? What will the layout look like? What is the supply, will it care about noise? How much, in what frequency bands?Maybe some of these components are important, and we can't possibly know without a deeper background on it.The graded series of capacitors are almost certainly inappropriate, as is the casein general, but likely don't do anything here.A coaxial connector, driven at 24V, seems like something that would be either an embarrassingly weak load for a 10A transistor (even the '3055 in the schematic), or an inappropriate choice of connector giving an inductive load (for Z < Zo and F ≪ λ/4, a transmission line looks like a series inductor) and thus the lack of ground-to-output catch diode is problematic. But that's only a suspicion without further information on what this thing is actually doing.Tim

author: Someone
author_rank: Super Contributor
timestamp: July 01, 2024, 11:42:11 pm
content: Quote from: T3sl4co1l on June 30, 2024, 01:10:09 pmThe cloud of topics around this poster has been "interesting" in the apparently wild approaches to non-specific-something-or-other application.Time to step off:https://www.eevblog.com/forum/projects/digital-buffer-delay-components-reply-thread-starteryef-smith-start-date2-minu/
uController freq generation? - Page 1
Forum section: electronics / projects

author: oceandesign
author_rank: Newbie
timestamp: April 15, 2020, 04:13:25 pm
content: I am working on a project where I need a accurate, stable low to no jitter square wave in the range of 0 to approx 300khz to 400khz. I need to be able to set the frequency with an accuracy of 1 hz steps or better. I would like to use a uController to do the job, the simpler the uC the better, there is not alot of processing power needed for other things, just a few buttons and LED, beeper for I/O, an I2C or SPI pins, channel of basic A/D and possibly D/A.It only needs a square wave (50% duty cycle) not sine or anything else so I don't think I need anything more complicated such as DDS like thishttps://www.qsl.net/zs1ayj/page11.htmI can't seem to get around the problem that at lower frequencies a clock of say 32MHZ is adequate for accurately creating a square wave but at 300khz there just is not enough accuracy there to get 1hz resolution or better, as far as I can figure out. Does anyone have ideas or suggestions or schemes how I might approach this?thanksCsquire

author: Kleinstein
author_rank: Super Contributor
timestamp: April 15, 2020, 04:28:13 pm
content: The task is not so easy as it looks, but it depends on the Jitter level needed. If the requirements are not so high one could use a DDS to generate a sine, followed by a comparator and divider (:2) to get exactly 50% on/off.With a µC it is relatively simple to have a simple divider, like 32 kHz / N and than a variable N of some 800 to a little of 1000. However this would not give 1 Hz resolution.The alternative to DSS would be some PLL system, but this may not be so simple or involve quite high frequency chips. One may still need an extra divider after the PLL chip as it may be easier to get some 300 MHz with 1 kHz resolution.
uCurrent Dead Bug Style - Page 1
Forum section: electronics / projects

author: kalhana
author_rank: Contributor
timestamp: June 14, 2013, 02:19:41 pm
content: I wanted to buy a uCurrent, so I went to the online distributor for Europe (robot-italy) and nearly checked out the item. It was around £70 including taxes and delivery. Then decided that I will try to make one.I would definitely buy one if it was a reasonable price like under £40 (as it is in Australia).I spent around £15 on parts, and a good few hours.So this is what I ended up with:(I only made it for personal use and not for commercial use)

author: EEVblog
author_rank: Unknown
timestamp: June 14, 2013, 10:57:10 pm
content: Cool
uCurrent Gold Circuit Fully Simulated in LTspice - Page 1
Forum section: electronics / projects

author: RonFred2
author_rank: Contributor
timestamp: July 12, 2018, 09:32:38 am
content: I thought others on this forum might be interested in seeing my youtube demo showing how to simulate the uCurrent Gold circuit using LTspice.Video:https://youtu.be/YHSaZG8h7cQLTspice zip file with uCurrent simulation and test jigs for each component:http://www.biophysicslab.com/portfolio/ucurrent-multimeter-adapter/

author: sourcecharge
author_rank: Regular Contributor
timestamp: July 14, 2018, 09:31:33 am
content: I got it simulated in B2spice too!although it only has the MAX4252 opamp instead.It works really well, and I was able to use it in low side, and high side current measurements.Now where do I get these in the states?(edited: just figured out as a noob how to order the pcbs for this from the gerber files given from the ucurrent home page.2 boards were 90 bucks)
uCurrent GOLD - oscillations - Page 1
Forum section: electronics / projects

author: Chupacabras
author_rank: Regular Contributor
timestamp: October 07, 2019, 10:19:35 am
content: I'm trying to make uCurrent, it is a good project for hobbyist.https://www.eevblog.com/projects/ucurrent/https://www.eevblog.com/files/uCurrentRev5schematic.pdfI have created in KiCAD, just copied Dave's schematic. And created my own PCB layout. I have used 0.1% resistors (instead of 0.05%).Problem is I see oscillations across R8, which is at the output of second opamp (see attached oscilloscope screenshot).I'm feeding 10mA DC to the input jacks, and expecting 10mV at the output jacks. Output of the first opamp gives 1mV (which is as expected). But output of the second opamp gives wrong values (negative millivolts - that is probably caused by those oscillations)I tried to change opamps, just to verify whether one of them is faulty. Didn't help.I tried to change capacitors, even tried to change values of C3 and C4 to 5pF or 30pF. Didn't help.What could be wrong?

author: Kleinstein
author_rank: Super Contributor
timestamp: October 07, 2019, 10:55:53 am
content: Dave also had some problem with oscillations, though I thing that was before adding R10 the 270 Ohms resistor at the virtual ground.AFAIR there was also an issue with the exact type for U2 - some where more stable than others.R8 at the output is a little odd and could be a problem, if there is a capacitive load to the output. For a test one could bridge this.Another point could be the layout U4 may also need some decoupling. Some Batteries can have a rather high impedance - so it may help to have an electrolytic cap at the supply somewhere (e.g. near U2 or U4). With R10 in place it could also help to have a capacitor from the VGND to the supply (e.g. negative side).

author: mikerj
author_rank: Super Contributor
timestamp: October 07, 2019, 11:02:27 am
content: https://www.eevblog.com/forum/blog/eevblog-1057-current-murphy/

author: Chupacabras
author_rank: Regular Contributor
timestamp: October 10, 2019, 06:13:16 am
content: Problem solvedThanks to mikerj for the link.I have tried many things and finally worked Dave's fix. Adding 100nF capacitors from V+ to virtual ground and from V- to virtual ground.
Ucurrent & high DC voltage - Page 1
Forum section: electronics / projects

author: amp_s
author_rank: Newbie
timestamp: May 05, 2016, 11:39:18 am
content: Hi everybody,I just bought ucurrent and I enjoy using it -:)But I have an idea, question, if anyone could comment please.It's about measuring leakage current in non-electrolytic capacitors (audio circuits).I use old instrument, Heathkit IT-28, capacitor checker, it delivers up to 600VDC.This instrument has an eye tube instead of panel meter.Although it works fine, I'd like to see a scale instead of opening or closing eyetube.I wonder if it's safe, according to high voltage present, to put ucurrent in series to measure leakage current.I'd switch it on only when I'm sure (eyetube status) that leakage current is below, let say 100mA.Thanks for your comment\sugestion!

author: EEVblog
author_rank: Unknown
timestamp: May 05, 2016, 11:43:40 am
content: No problem provided the meter you use it floating. The uCurrent does not care what voltage it floats at.

author: Ian.M
author_rank: Super Contributor
timestamp: May 05, 2016, 11:47:53 am
content: However it certainly wouldn't be safe to touch (e.g operate uCurrent range switch) with the HV present.

author: amp_s
author_rank: Newbie
timestamp: May 05, 2016, 11:49:59 am
content: Floating, yes, it's analogue multimeter with batteries.Sure, I am aware of high voltage around ucurrent for this case.Thanks, will try this evening!

author: qwaarjet
author_rank: Regular Contributor
timestamp: May 05, 2016, 01:18:33 pm
content: at former lab I worked at we routine used the UCurrent in the 6KV+ range floating and ground referenced. we also blew up a lot as well when things shorted out, which was common but there are super easy to repair.

author: amp_s
author_rank: Newbie
timestamp: May 05, 2016, 09:50:41 pm
content: Just finished with testing.It works, excellent, now I can see how much I failed with calibration.And soon I found too many (too) leaky caps
uCurrent multimeter 2mm tip compatible mod - Page 1
Forum section: electronics / projects

author: nukie
author_rank: Frequent Contributor
timestamp: June 28, 2012, 05:04:05 am
content: Hi all,This is my humble contribution to the eevblog community.I only use my multimeter leads with the uCurrent. I constantly find myself getting frustrated with the loose multimeter leads falling off the holes of the banana sockets so I wanted something that is secure mechanically and electrically. So I rummaged through my parts and found these 2mm sockets and they pop right into the existing holes. Most multimeter tips are 2mm so this should be pretty good and hopefully they don't wear out the surface of the tips quickly.Just remove the existing banana sockets and replace with these 2mm sockets, then solder a wire to the pcb trace. This mod saved my day!You can find thenm very cheap at electronic parts store. Look for "2mm sockets".

author: EEVblog
author_rank: Unknown
timestamp: June 28, 2012, 06:55:51 am
content: Yes, good solution for direct probes.Dave.

author: SeanB
author_rank: Super Contributor
timestamp: June 28, 2012, 03:35:13 pm
content: Very good idea, most will have the standard multimeter leads almost permanently attached to the meter.

author: robrenz
author_rank: Super Contributor
timestamp: June 28, 2012, 04:59:02 pm
content: No mod necessary with these.Pomona Pin Jack to Banana Plug; Brass (Plug); Beryllium Copper; 2500 WVDCModel 1809-0 is blackModel 1809-2 is redPDF shows dimensions

author: BravoV
author_rank: Super Contributor
timestamp: June 29, 2012, 06:48:58 am
content: Cool idea, thanks.Sharing my different approaches when using my ucurrent.1st pic, using cheap banana connectors for audio speaker since it has the crimp to hold the probe's tips firmly & steady.2nd, Banana to BNC connector when using logger or scope.
uCurrent range - Page 1
Forum section: electronics / projects

author: mvdzwaan
author_rank: Newbie
timestamp: June 05, 2015, 12:59:29 pm
content: Just received my uCurrent Gold and it's a great product.I do have some questions regarding its use* Is it allowed to change the range switch while in-circuit ?* Each range has a specific current range. What to do if I have a mcu+gprs chip which I want to measure during it's complete wakeup/sleep cycle. Idle its at ~40mA, in sleep it might drop <1mA (so uA range), but during startup is might actually peak at 2A (never seen anything above 0.5A btw)

author: MLXXXp
author_rank: Frequent Contributor
timestamp: June 05, 2015, 08:24:17 pm
content: Quote from: mvdzwaan on June 05, 2015, 12:59:29 pmI believe the switches are break-before-make. In order to prevent possible excessive voltages across the op-amp, and also removing power to the circuit, when the shunt is removed briefly while switching ranges, you should switch the power switch toSHORTbefore changing the range switch, and then switch the power switch back toON.For a discussion of highly variable current measurement, see:https://www.eevblog.com/forum/projects/precision-current-measurement-in-multiple-ranges/
uCurrent & Extech 330 & Rigol 1054Z - Page 1
Forum section: electronics / projects

author: mvdzwaan
author_rank: Newbie
timestamp: June 14, 2015, 05:06:31 pm
content: I'm trying to get a baseline power consumption for a custom board I'm building. It contains an ATMega 1284p and an ATMega 328p together with a SIMcom 808. Both ATMega's are running from their internal 8 MHz oscillator and are powered by a 3.7V LiPO. Everything is running like it should. Main power is decoupled using the SIM808 suggested capacitors, and the ATMega's all have 100nF decoupling on each Vcc line. Using the fuses I've disabled BOD for now (in the end will run at the 1.7/1.8V BOD setting)I have not powered up the 808 yet, the 328p is sleeping forever, and the 1284P is sleeping 500ms, doing nothing and sleeping again. This way I'm expecting <0.1mA,To validate I've hooked up the uCurrent on the mA/mV range right after the LiPO and am testing it with a Extech 330. I'm getting 0.7mV so 0.7mA, but when I switch to the uA/mV range I get 1.265V (so it's limited by the range, but I would have expected 700mV).So first off I probably have a problem with the board as it's consuming too much, but how much....I also hooked up my DS1054Z in parallel with the extech but this one gives even stranger readings. I'm looking at Vmax/Vmin and Avg, and got 236mV-> -208mV, with average 3.2mVIn all cases my power consumption is above spec, but to really troubleshoot this, I need to find out what I'm doing wrong with my measurement...

author: miguelvp
author_rank: Super Contributor
timestamp: June 14, 2015, 07:10:47 pm
content: Maybe this video helps:Edit: BTW you don't have to use the integral math function since I think the DS1054Z has meassurement for area as Dave explains towards the end of the video.
uCurrent schematic problem - Page 1
Forum section: electronics / projects

author: fedimakni
author_rank: Regular Contributor
timestamp: June 20, 2020, 04:20:23 am
content: Hello,regarding ucurrent design I was confused about the L203011MS02Q switch mentioned as SW2 in the design. for the off situation 3A to 3B and that's understandable, but during the on station it should connect 2A to 2B which means the net V+ ti +IN and in that case it will disconnect battery from the device which i couldn't understand how??Is there any mistake i am doing during understanding the schematic? (schematic is down below)Looking forward for your explanation.Thanks

author: bdunham7
author_rank: Super Contributor
timestamp: June 20, 2020, 04:27:53 am
content: If I understand you, you are misreading the switch diagram. No A terminal is ever connected to any B terminal. The blue "U" shape shows it connecting adjacent terminals on their respective sides. For example, in the 'ON' position, 2A to 3A are connected, as well as 2B to 3B.
ucurrent with mosfet - Page 1
Forum section: electronics / projects

author: fedimakni
author_rank: Regular Contributor
timestamp: June 21, 2020, 08:18:34 am
content: Hello,I am planning to make a ucurrent but the ranges will not be controlled manually but using mosfet (schematic attached below). I choose to use the DMG3406L datasheet:https://www.diodes.com/assets/Datasheets/DMG3406L.pdfas an n-channel mosfet and i plan to turn it on and off from the raspberry pi. I will power this device from the raspberry pi 3.3V pin.But also the DUT (device under test) will also be powered from the same pin. and as i planned to use a low side measurement the GND and -IN pin could be the same net.I would like to have an idea does this could really work?Do the mosfet will turn on and off normally as the voltage reference of the gate may not be the same with the voltage in the source?Is there any enhancement i could do?Thanks

author: SilverSolder
author_rank: Super Contributor
timestamp: June 22, 2020, 02:09:39 am
content: Quote from: fedimakni on June 21, 2020, 08:18:34 amThe MOSfet in series with R1 may have higher Rds(on) than R1 itself - and will therefore introduce significant measurement error. The MOSfet probably needs to be placed somewhere else, where it is not being "measured" by the uCurrent...

author: fedimakni
author_rank: Regular Contributor
timestamp: June 22, 2020, 02:14:21 am
content: Could you please suggest any enhancement? Where I need to place it?Another thing, driving the mosfet from a 3.3V source with GND reference but the mosfet has the source connected to -IN which has a different voltage level than GNd, Do that could cause some problem during powering on and off the device?Thanks

author: SilverSolder
author_rank: Super Contributor
timestamp: June 22, 2020, 02:22:52 am
content: It might make sense to think in terms of replacing the uCurrent's sliding switch range selector with a relay or two.

author: fedimakni
author_rank: Regular Contributor
timestamp: June 22, 2020, 02:27:38 am
content: A relay is very slow to make the switch also i think here we are dealing with max of 1A and most of the case with few uA so do you think it's a good idea?

author: apoorv3in
author_rank: Contributor
timestamp: June 23, 2020, 11:12:43 am
content: Have a look at this.

author: apoorv3in
author_rank: Contributor
timestamp: June 23, 2020, 11:19:55 am
content: I am working on something similar it turns out not to be that simplehttps://www.eevblog.com/forum/projects/current-wave/msg2840098/#msg2840098

author: SilverSolder
author_rank: Super Contributor
timestamp: June 23, 2020, 03:20:27 pm
content: Using a couple of relays will simplify the project enormously and you won't have to deal with the resistance and temperature dependence of the MOSFETs introducing problems.How often and how fast do you envision changing the range? - a relay will be fine, for most imaginable purposes.Many (most) professional instruments use relays for range switching... for good reasons!
UDC package: QFN with some pins moved under the package - Page 1
Forum section: electronics / projects

author: DutchGert
author_rank: Frequent Contributor
timestamp: March 28, 2014, 02:58:22 pm
content: At first I thought my library was wrong but no, it was actually spot on.....Most wierd package I have seen in years.... Anyone any idea why they make it like this?

author: DutchGert
author_rank: Frequent Contributor
timestamp: March 28, 2014, 03:11:16 pm
content: Hmm, looking at the application note i get why they place the pads like this but stull, seems a bit far stretched to modify a package just for a specific aplication.

author: TiN
author_rank: Super Contributor
timestamp: March 28, 2014, 03:51:22 pm
content: Likely did that for thermals, as that's power train output.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: March 28, 2014, 04:02:10 pm
content: Surprised it's not a BGA. I guess a thermal pad type wouldn't work very well. Could've moved ground in the middle and put power out all pads one side? Maybe a double pad? Kinda gets at the same thing though.Meh, those power packages do things weird some times.Tim
uF capacitance meter with up to 50 mV p-p excitation signal - please help - Page 1
Forum section: electronics / projects

author: lisandroc
author_rank: Newbie
timestamp: April 21, 2014, 07:55:56 am
content: Hi everyone! I am new in this forum, and I really need some help, please.I have a PIC based circuit and I need to add a capacitance meter to this circuit. Here are the main characteristics needed:- Excitation voltage cannot go higher than 50 mV p-p or less if possible (this is the most important problem).- I need to measure capacitances at about some uF.- I do not care so much on precision, but I need to monitor the change in capacitance since this is a sensor.- I need the PIC to read it so that I can work with it.I tried the AD775/6 but they measure up to many pF which is too low for me. I have been looking around for circuits but they all use high voltages for excitation. Moreover, one of the things I am afraid the most is noise in the signal since 50 mV p-p is very low.Please, any ideas are welcome, even the most crazy ones, I will try them!Thanks!!!!

author: Fank1
author_rank: Regular Contributor
timestamp: April 21, 2014, 11:26:19 pm
content: You could try pulsing an output on the pic thru a 1k and 10 ohm resistor in series. Assuming a 5 V pic.take the junction point to the cap to be measured and back to an analog input on the pic.you could then vary the pulse rate and width until the voltage got to a readable threshold level.spice it up to get an idea of the rate and width needed.

author: lisandroc
author_rank: Newbie
timestamp: May 10, 2014, 04:24:29 am
content: Thanks! I will try it!

author: w2aew
author_rank: Super Contributor
timestamp: May 10, 2014, 01:47:08 pm
content: Another idea - send a constant current into the capacitor and measure how long it takes to charge to 50mV. Range changes can be done by changing the value of the current source. Use a FET to short the current source (and capacitor under test), then open the FET and let it charge. The charge time will be linearly proportional to capacitance. time = current / capacitance.
UFH Control Wiring Question (230VAC->24VAC)  - Page 1
Forum section: electronics / projects

author: carlossless
author_rank: Newbie
timestamp: April 22, 2022, 07:50:01 pm
content: Hey all,I have been recently blessed with the opportunity to install some electrical underfloor heating controls for my relative's apartment after the original contractor flaked out on us. They bought all the parts, but weren't able to do that actual installation - in the end, I decided to do it myself.The parts they bought (actuators and thermostats) are all made for 230VAC systems, but the wiring from the heating controls place to the thermostat locations in the rooms is all cat5e. Now, this immediately turned on some alarm bells in my brain - surely I am not going to run 230VAC over cat5e, but after calling the contractors I was told that it would be enough to tie 2 of the conductors together for that to be ok (honestly why not tie four at that point?).Anyway, having not done this before and not having a strong desire to burn any houses down, I decided to (potentially) over-engineer the problem and decided to use 24VAC for the control circuit (which is the lowest voltage the thermostats also supported) and do 230VAC switching for the actuators with a separate array of relays.Since I am an amateur having worked mostly with low-voltage digital stuff, I am looking for opinions from the EE pros. Am I an idiot for doing this? Is this actually safer? Or have I missed some critical flaw here.Thanks!

author: tooki
author_rank: Super Contributor
timestamp: April 23, 2022, 02:41:47 pm
content: I’m not an electrician, but a quick search says that Cat5 cable is rated for 100V maximum. The insulation isn’t designed for 230V (never mind any surges or spikes that could happen).Imagine what your insurance company would do if your house caught fire and they found 230V connected via LAN cable… That’s if you survived the fire, that is…I think your approach seems much smarter.

author: themadhippy
author_rank: Super Contributor
timestamp: April 23, 2022, 02:59:53 pm
content: Quoteyou can find cat 5 cable with a 300 or 500v rating,however that's to allow it to be used were its installed alongside mains wiring to comply with the "insulated to the highest voltage present" rule,and no way should it be used for anything but extra low voltage
Ugly twist to a programmable load - Page 1
Forum section: electronics / projects

author: joeqsmith
author_rank: Super Contributor
timestamp: May 03, 2015, 09:38:29 pm
content: My voltage controlled current source based around a switching regulator.

author: Christopher
author_rank: Frequent Contributor
timestamp: May 03, 2015, 10:23:33 pm
content: Interesting to see your circuit.Have you considered dumping the power into a battery or something?At work we burn in power supplies and use loads which end up re powering the grid. Very nice compared to burning up 50kw in heat 24x7

author: joeqsmith
author_rank: Super Contributor
timestamp: May 05, 2015, 02:01:27 am
content: Quote from: Christopher on May 03, 2015, 10:23:33 pmGlad you found it of interest.I had seen a post where a member had asked about using a switching load rather than linear and thought it may be interesting to play with. It wasn't. One thing that was mentioned was using a resistor to burn off the energy. For this circuit, the majority of heat is going to be in the IGBT and FRED. After that the inductor and 4-wire sense.I had not considered doing anything with energy recovery. There's a pretty big benefit if you can recover some of your 50KW. This thing with that tiny heat sink is not going to handle any sort of power for any length of time. The circuit has so many disadvantages anyway, it really was a pointless effort. There was a post where someone mentioned feeding energy back into the supply being tested. I see no reason this could not be done.

author: Christopher
author_rank: Frequent Contributor
timestamp: May 05, 2015, 05:34:08 am
content: Yeah, no matter what you do you still loose power into a heatsink unless you are smart and recycle some of the powerAnyway, it's good in winter, makes for a good footwarmer

author: Phoenix
author_rank: Frequent Contributor
timestamp: May 05, 2015, 07:17:22 am
content: Quote from: joeqsmith on May 05, 2015, 02:01:27 amThis was actually a final year university project at my old research group (for a 3 phase inverter -> 3 phase active rectifier load), from the results I saw it worked pretty well. You would need to keep in mind common mode current paths and noise injection.It also comes to mind that one good reason to create a switching version is to use it as a 4 quadrant (AC) load... but that requires a power supply on the load side capable of delivering energy and absorbing it.
Need help in upgrading audio amplifier SMPS psu for better efficiency and power - Page 1
Forum section: electronics / projects

author: criss6100
author_rank: Newbie
timestamp: May 25, 2023, 09:12:08 am
content: Hello and a good day to all of you,I have a Macrom M1A4150 audio amplifier, its an old school amplifier, and out of curiosity to learn and have some fun along the way I want to upgrade the PSU part of itI have attached the schematic, what I was thinking was:1. Upgrade the filter caps from 2200 x 4 and 3300 x 4, to 8 x 6800uf 35V (have some Nichicon PM laying around)2. replace the IC from JRC4558 to a TL072 or NE5532, would this improve anything regarding electric noise in this circuit? Would there be a better alternative for this IC?3. replace the IRFZ44N FETs for something more modern with better current and voltage capacity and best of all with lower RDS(on), here I was thinking IRF3205 FET's? Will they work without modifing the pulldown/up resistors?Also would anyone suggest any other improvments than can be made on this PSU? I am trying if possible to increase its efficency and maybe max power output.In this amplifier the PSU is the limit when running the 4 channels in bridge mode at 4ohm'sThank you all for your time and help with this little project, and I hope to learn and have fun from itChristian
UHF Repeater Click Counter Control 555? - Page 1
Forum section: electronics / projects

author: Sivand12
author_rank: Contributor
timestamp: November 20, 2014, 11:11:11 am
content: I'd appreciate some direction on building a "Click Counter" to send say Four Clicks in ten seconds toactivate a repeater and say six clicks to turn it off.I recall building one decades ago with a bunch of 555's but my memory fails me now.The idea is that lots of UHF walkie Talkies don't have DTMF but have 120 odd sub audible tones.I'd take the audio out and have that trigger a master timer and then subsequent timers.I"m also guessing that it's probably a whole lot easier to do with a PIC or atmegahowever I've been out any electronic kit construction for a long time.I've ordered a pic 2 and an uno, but its going to take some time to learn.I'm wondering if a series of 555's could be a very simple way of achieving this.As a matter of interest, Aviation uses Remote outlets, you click 4 times,a radio grabs a phone line, sends a DTMF burst and the remote phone VOXtriggers the remote radio.Congrats Dave on your You Tube Video's and this web site.
UHF Repeater Click Counter Control 555? - Page 1
Forum section: electronics / projects

author: Ramjet555
author_rank: Newbie
timestamp: August 30, 2014, 05:12:33 am
content: I'd appreciate some direction on building a "Click Counter" to send say Four Clicks in ten seconds toactivate a repeater and say six clicks to turn it off.I recall building one decades ago with a bunch of 555's but my memory fails me now.The idea is that lots of UHF walkie Talkies don't have DTMF but have 120 odd sub audible tones.I'd take the audio out and have that trigger a master timer and then subsequent timers.I"m also guessing that it's probably a whole lot easier to do with a PIC or atmegahowever I've been out any electronic kit construction for a long time.I've ordered a pic 2 and an uno, but its going to take some time to learn.I'm wondering if a series of 555's could be a very simple way of achieving this.As a matter of interest, Aviation uses Remote outlets, you click 4 times,a radio grabs a phone line, sends a DTMF burst and the remote phone VOXtriggers the remote radio.Congrats Dave on your You Tube Video's and this web site.