hybridfree/eevblog-posts huggingface dataset:
Growatt grid connect inverter into island mode? - Page 1
Forum section: electronics / projects

author: GabYoung92
author_rank: Regular Contributor
timestamp: April 07, 2014, 09:08:02 am
content: I have a Growatt 1500 grid connect inverter.It works but has to sense an AC voltage on the output to 'sync' to. Ive put it in parallel with another inverter and the unit begins to produce power.I've tried to communicate with it using the rs232 port to see if i can get a menu system, but it won't respond.What I want to know, can these units be put into an "Island Mode" where it will act just as a standard inverter, or is there some way to "jump start" it?

author: VK5RC
author_rank: Unknown
timestamp: April 07, 2014, 10:09:27 am
content: Sorry I can't be more definite but I was talking to a work (both not EE) friend today about exactly the same topic, 'he said' the inverters are set to avoid this to reduce electrical hazards to linesmen in the event of grid failure and they are working on supposedly not live wiring.

author: NiHaoMike
author_rank: Super Contributor
timestamp: April 07, 2014, 01:31:44 pm
content: There's really no point as a grid tie inverter is much more expensive than a conventional inverter. Also, grid tie inverters are current output while conventional inverters are voltage output.

author: GabYoung92
author_rank: Regular Contributor
timestamp: April 07, 2014, 10:31:54 pm
content: Quote from: NiHaoMike on April 07, 2014, 01:31:44 pmI have about 15 of these units ranging from 1.5kw to 4.7kw already so I was trying to make use of themSo I'm pretty much at a dead end with these?

author: NiHaoMike
author_rank: Super Contributor
timestamp: April 08, 2014, 12:07:02 am
content: You'll do better selling them and then buying the regular kind.Here are some reviews to look at:https://www.youtube.com/user/knurlgnar24/videos
Grrr!  Wasted hours... - Page 1
Forum section: electronics / projects

author: colorado.rob
author_rank: Frequent Contributor
timestamp: September 10, 2018, 12:56:27 am
content: I just spent many hours chasing down a problem trying to get current on an STM32L4 chip down to 3uA in stop mode. Once I initialized the RTC or UART, I could never get the current consumption below 250uA. I thought at first it was a board/GPIO issue, but the RTC uses no GPIOs. Even initializing just this one IP block caused the problem.I decided to try this on a Nucleo64 dev board I had lying around and the same code just worked.I finally convinced myself that I could have damaged the MCU during the initial PCB power-on where I had a wiring mistake that took one of the power domains well below its 3V3 nominal value. The weird thing is the rest of the chip worked flawlessly. It was just this odd Stop mode current issue. The MCU even drew the expected current in standby or shutdown mode.I replaced the MCU and the code I was working on for two daysjust worked.

author: Mr. Scram
author_rank: Super Contributor
timestamp: September 10, 2018, 01:56:19 am
content: This is why I generally order two or more of something. I love being able to do a sanity check with a second part. It typically shows me the problem isn't in the part, but in the designer.

author: coppercone2
author_rank: Super Contributor
timestamp: September 10, 2018, 02:12:27 am
content: or the programmeror the compileror the cableor the physical location (i had a mcu that kept randomly resetting when it was in a particular location, the thing was so bad I had to put a notebook ontop of the esd mat and it was fine, the things on isolated brass stand offs!)or the angle (cracked socket)

author: LapTop006
author_rank: Unknown
timestamp: September 10, 2018, 04:11:57 am
content: Last week for me being convinced I'd killed a board due to overvoltage (the old HP supply it was hooked up to makes it *very* easy to add an extra few volts), then the next day while using that board as a reference noticed I'd simply failed to solder the data pins on the UART and that was why the board seemed dead.

author: dmills
author_rank: Super Contributor
timestamp: September 10, 2018, 09:14:52 am
content: I spent a good week chasing 'faulty relays' on a batch of production board at work.Could NOT for the life of me reproduce on my bench, but the test department were having all kinds of issues...The problem?The test departments signal source had a honking great loudspeaker in **JUST** the wrong place, and they were resting the DUT on top of the signal generator causing the speaker magnet to hold the relay in! Oh how we laughed.Regards, Dan.

author: Zucca
author_rank: Unknown
timestamp: September 10, 2018, 10:13:57 am
content: Quote from: colorado.rob on September 10, 2018, 12:56:27 amSo you can damage the MCU if you apply 1V instead of 3V3? I always thought the components damages are due to overvoltage not undervoltage situations. Wired...Maybe there were others MCU power rails on, while one was down....

author: xaxaxa
author_rank: Regular Contributor
timestamp: September 10, 2018, 02:40:12 pm
content: looks like esd damage to me
GSM microphone for voice recording - Page 1
Forum section: electronics / projects

author: akis
author_rank: Frequent Contributor
timestamp: November 28, 2016, 10:01:37 pm
content: HelloI have used a couple of "tracking" devices with audio monitoring and the sound quality is abysmal even with very good GSM signal (both Chinese admittedly).Back in the days I had made a very simple "bug" (PCB fitted on top of a PP3 battery, so very small) which consisted of an electret mic with one or two transistor gain stage coupled to a Colpitts oscillator at the 88-108MHz FM so you'd tune your radio in on it. And it was superb, the sound clarity was phenomenal you could clearly hear people in a room breathing in! It was not stable and would drift (the coil was a few turns only and very sensitive) but the sound quality was fantastic.These modern tracking devices are nowhere in comparison. Therefore I want something better and am examining ideas. For example an old phone which somehow can auto answer if it gets called? Or an old phone that can somehow run an app that will monitor sound levels and if over a threshold will then dial a certain number ? Or maybe an Arduino project, for example an Arduino Mini Pro controlling a MAX9814 board (http://www.ebay.co.uk/itm/MAX9814-MAX9812-3V-12V-Electret-Microphone-Amplifier-Module-Board-for-Arduino-/272426330662?var=&hash=item3f6ddfea26:m:mN2twgZ4lCeHU02CRMnBEEw) and some other GSM board ?All ideas welcome.
GSM network activity - Page 1
Forum section: electronics / projects

author: hamdi.tn
author_rank: Frequent Contributor
timestamp: September 28, 2016, 02:32:10 pm
content: Hi everyone,Am working recently with a GSM module SARA-G350 and trying to put it in low power mode. while the module itself clearly switch to low power mode ( am monitoring current going througt VCC) and waking up after a period defined by the network (DRx) so far so good.But it keep waking up by some random unknown activity different from the network paging. but it's also related to the network as it stop when deregister from the network, and i get different behavior if i switch to an other operator. i also detached GPRS connectivity from network.anyone got any idea what are the possible network transmission that can occur while not in call or data mode, and not paging.Thanks.
gsm-sms and mcu help and ideas for a noobie - Page 1
Forum section: electronics / projects

author: kat3876
author_rank: Newbie
timestamp: July 09, 2011, 04:02:05 pm
content: first my intro i am new to this kind of setup and programing but i do have some knowledge of electronics as i am an auto tech and industrial maintenance tech and now a machine builder for capacitor winding machines in Florida. now onto what i would like to do is basically be able to monitor a vehicles functions as well as directly interact with it as well with up to 20 i/o via sms text . this will be a low volume deal so components can be moderately priced at first . i have seen a few small apps on the net with 1 or 2 i/o but not 20 per say. i have a firm grasp on the relay and voltage setup on the i/o from the vehicle side but what kind of mcu to use ? that is no ob friendly as well as the programing and then marry that to a gsm module with maybe a gps capability. also keeping in mind witch carrier to use Verizon etc that would be the cheapest {Sims card ?} any and all help would be appreciated as well as criticism lol if i don't understand and ask the dumb questionsthanks again for your time and patiencedon

author: Bloch
author_rank: Unknown
timestamp: July 09, 2011, 05:37:26 pm
content: Hi DonThe most easy / fast route to go i with something like thishttp://www.audon.co.uk/elc18.html

author: kat3876
author_rank: Newbie
timestamp: July 10, 2011, 05:49:17 am
content: thank you Bloch i will look into that as i am familiar with plcs and their associated programingthanksdon
GSM/Wifi livestock sensor data retrieving - Page 1
Forum section: electronics / projects

author: gonzalito
author_rank: Contributor
timestamp: April 26, 2019, 11:45:58 am
content: Good evening everyone,my name is Gonzalo, I´m a mechanical engineer and I come here looking for answers to a couple of questions.What Im needing is a system that can read RFID tags, store data from when that tag has been read, and then send via GSM/Wifi all the aqcuired data to a server in the cloud.This will be used in cows, and retrieve data of the behaviour.Other needs for the project are.- Low battery consumption. It will be running on batteries, and battery replacement will not be an easy task.- I guess it might not have GSM signal sometimes, so all of the data should be stored for later sending when GSM signal is up again.- Data sent should not be doubled. After data is uploaded in the server it should be allowed to be erased from the transmitter. This in order to not let any of the data be lost.The question is, how would you face this? Using an esp mcu and sim800l? As this should have power saving features the system should be woken up whenever a read has to be taken.Since I also do not know how to code I´ll be passing all this info to someone that actually can. Idk, maybe even make it a collaborative project. Where can this be done?Thanks!,Gonzalo.
GTL20003 - Page 1
Forum section: electronics / projects

author: MyElectronsFellOut
author_rank: Regular Contributor
timestamp: September 01, 2015, 07:17:48 pm
content: Looking at the datasheet page 5, can I get away with just the Microcontroller pull ups on the data lines for bidirectional translation or not?http://www.nxp.com/documents/data_sheet/GTL2003.pdf
GTL2002 level-shifter collapses while driving WS2812 pixels - Page 1
Forum section: electronics / projects

author: zzattack
author_rank: Regular Contributor
timestamp: September 14, 2017, 11:26:16 am
content: I'm trying to drive some adafruit neopixels with 'ws2812' chip from a 3.3V micro.To get 5V signals I'm using a GTL2002d to level-shift the mcu outputs, schematic attached.Measuring the output when no display is connected, I can see the 3.3V microcontroller output signal is properly shifted to 5V. Scope picture attached.The problem exhibits when I connect a string of these pixels to the 5V signal. It seems both the 3.3 and 5V signals 'collapse'. Lowering the pull-up sizes slightly reduces the drop not significantly so. A 4-pixel string still recognizes the input signal, but my next size up (8/64) pixel displays don't respond to the signal at all. This seems weird, as the first pixel is supposed to consume and reproduce the signal it receives up to arbitrary length.The 3.3V signal is the MOSI generated by a SPI peripheral on a STM32F4.Adding a 330 Ohms series resistance before the pixels significantly reduces the drop, but when putting the scope on the signal behind the resistor shows a nearly flat line and ground level.
GTL2003 Problems with totem-pole drivers - Page 1
Forum section: electronics / projects

author: Electr0nicus
author_rank: Regular Contributor
timestamp: April 10, 2013, 12:11:37 pm
content: Hi everyone!I have a problem using a GTL2003 bidirectional Level shifter.http://www.nxp.com/documents/data_sheet/GTL2003.pdfThe background:I want to level shift a parallel display data bus from 3.3V to 5V. The fequencies are pretty high, (pixel- clock has approx. 26MHz). I'm using ac- termination on the end of the databus. This just works fine, the signal is really clean compared to the look of the signal when unterminated (@ no load). All signals are measured with a ground sping on the oscilloscope probe instead of the usual ground clip.Here is the signal without termination. It is really horrible as you can see. This is because of the long ribbon cable (approx 20cm).After adding a parallel AC- termination using a 470pF cap and a 47ohm resistor, the signal looks really clean.Those terminated signals are fed into the GTL2003 device. The device is practically a array of 8 pass FETs and one reference transistor. According to the datasheet, for shifting the signals up to 5V there will be a pullup transistor required on the output of the GTL2003. The problem I now have is that the signal isn't shifted up to 5V at all. It pretty much stays absolutely the same.Whatever pullup resistor I use on the output (tried 10k 2.2k 1k 470R 100R) the voltage level of the signal stays the same.Also the voltagedrop= current across the pullup- resistor (1k) is very interrestingThere is 2mA DC- current flowing into the output of the GTL2003 the whole time, generating a voltage drop of 2V across the resistor, of course overlayed by the signal's waveform. According to the datasheethttp://www.nxp.com/documents/data_sheet/GTL2003.pdfon page 4 chapter "Function selection" under "Function selection, LOW-to-HIGH translation" when there is a high level on the input then the pass transistor is nearly off. But there is nowere definded what "nearly off" means. So I would think this would explain the static DC- current flowing from the 5V output side trough the pass transistor down into the 3.3V logic driver (totem pole) and up into the 3.3V rail.So my question is simply: Is there a connection scheme of those GTL devices, which can be used with totem pole output drivers on the lower side. Because as the situation is now, I could lower the pullup resistance even more, until the pass transistor or the totem pole output driver on the lower side gives way. But as long as the resistance of the pass transistor in "nearly off" state is low enough and the low side driver is strong enough to consume the current fed back from the 5V side to its input, the output will never be nearly 5V.Thanks Gregor
GTX1080 Memory VRM Going into OVP - Page 1
Forum section: electronics / projects

author: Snoopy04
author_rank: Contributor
timestamp: December 19, 2018, 11:32:35 pm
content: Hi,as the Title suggests I've got a Problem with a GTX1080 from Nvidia. I've bought it as defective for a few (relative) Bugs and I'm now trying to repair it.I think the main issue was an Overcurrent sittuation on the PCI-E 12V Rail because the Fuse (10A) was Blown.Surprisingly none of the VRMs, which rely on this Voltage, or the MOSFETS of the Main VRM for the Memory was in Short. I've checked both MOSFETS with a Multimeter in Diode Mode an everything seems to been just fine.After changing out the Fuse of the Rail, the Card seems to work Normal except for the fact that there is no Image. The fans are Controlled and The Card is recogniced by my Computer. (With help of another dedicated GPU). After further Investigation I found that there was no memory Voltage Present. So my first thought was that some of the Control lines for the Controller IC (RT8816 )are not in proper state.Turns out everysingle Line Voltage is where it should bee.So obviously the Controller IC must have died in the Overcurrent. Therefore the Memory is not Powered and I'm not getting a picture.I've searched nearly everywhere but I couldn't find an exact replacement for it. So after further Research I've comealong a NCP81278 which seems to bee a complement of the RT8816.But after trying out and Comparing the two datasheets even more I think now that there are indeed some differences.After Powering the Card with the NCP81278 the Memory VRM tries to Provide Power but shortly is switches off due to Over Voltage on the Output. (High Side FETs are disabled and LOW side Enabled)It's doing some weired stuff.REFIN Voltage is around 1.35V so if I've understand the working principle correctly the Output Voltage of the Memory VRM should be 1.35V. Instead it exceeds 2V before it finally shut's off.My first thought was that there is something wrong with the LOW side of the DUAL MOSFET but after Goofing around with my Oscilloscope I don't think so. See my Attachments.In the Picture I've marked the Gates of the LOW side MOSFET, the HIGH Side MOSFET and the Output Voltage after the Coil. I've moved the Wavefomes a little bit so you can read the Lables.Has anybody an Idea what's going onSomeone who is more into VRMs or Buck Converters.

author: dmendesf
author_rank: Frequent Contributor
timestamp: December 20, 2018, 04:07:21 pm
content: It could be a problem in the feedback or compensation network. One idea would be to remove the VRM or cut it's input somehow and power the memory bank from an external power supply to see if this is the only problem remaining.

author: wraper
author_rank: Unknown
timestamp: December 20, 2018, 04:20:12 pm
content: Quote from: Snoopy04 on December 19, 2018, 11:32:35 pmAliexpress is full of RT8816. It is available on ebay too.

author: wraper
author_rank: Unknown
timestamp: December 20, 2018, 04:35:58 pm
content: There is a difference of pin 9 (TON/FS) operation. Direct replacement as minimum will cause incorrect switching frequency.
Guard Ring - Page 1
Forum section: electronics / projects

author: dreaquil
author_rank: Regular Contributor
timestamp: July 21, 2015, 07:28:42 am
content: Hi everyone,I was wondering if anyone would be able to help me in creating a proper guard ring in order to reduce surface leakage. I understand that I must surround the high impedance nodes with a track and connect it to one of the nodes but to completely surround them isn't possible without shorting them together... does this mean surround them and leave a small gap in order to not short them? I'm quite confused.

author: owiecc
author_rank: Frequent Contributor
timestamp: July 21, 2015, 07:36:49 am
content: Do not short the guard ring to the high impedance node, this way the guard ring would need guarding. You need to go all the way around the HiZ node. Maybe you will need to make the node physically smaller. Take a look at google images "guard ring pcb" to see how it is done. The guard ring has to be low impedance and its potential should be very close to the guarded node. Is should not have solder mask.

author: dreaquil
author_rank: Regular Contributor
timestamp: July 21, 2015, 08:10:02 am
content: How do I route to other things if the high Z node is completely surrounded? Can I leave a small gap?

author: dreaquil
author_rank: Regular Contributor
timestamp: July 21, 2015, 09:38:51 am
content: For anyone who comes across this post in the future, further to the great information provided by owieccm I also found this application note from LT which helped me out.http://www.linear.com/solutions/1853
Guard traces on Hioki DT4256 - Page 1
Forum section: electronics / projects

author: golfballs32
author_rank: Newbie
timestamp: April 16, 2018, 10:35:00 pm
content: After watching EEVblog #973 about the Hioki DT4256 multimeter, i have questions about the use of guard traces in it. At around7:16there are guard traces on the meter. I assume that these are the measurement traces coming from the input jack/current shunt. I have heard that guard traces do not make much of an improvement on a board with ground planes, which i presume this has.Do the guard traces provide any serious benefit or is it just gilding the lilly?

author: Siwastaja
author_rank: Super Contributor
timestamp: April 17, 2018, 02:55:29 pm
content: You are probably thinking about not needing ground fills between the traces in a 4-layer (or more) design with a closeby ground plane from AC effects viewpoint.Guard traces like this are against DC leakage due to board surface contamination. They are often actively driven to the same voltage level as the trace being guarded. Ground fill below has nothing to do with this.
Guess how old is it? - Page 1
Forum section: electronics / projects

author: blueskull
author_rank: Unknown
timestamp: February 05, 2015, 03:45:57 am
content: I got one of this thing, a LED, metal packaged, with epoxy lens.Can anyone guess how old it is? I'll publish the answer a day later.Also, guess where it came from?

author: codeboy2k
author_rank: Super Contributor
timestamp: February 05, 2015, 07:16:52 am
content: 1970s russian led?

author: T3sl4co1l
author_rank: Super Contributor
timestamp: February 05, 2015, 02:21:02 pm
content: Gonna say mid 60s, possibly green (GaP).Tim

author: DmitryL
author_rank: Regular Contributor
timestamp: February 05, 2015, 03:33:22 pm
content: Quote from: codeboy2k on February 05, 2015, 07:16:52 amDoesn't look like it. Soviet LEDs in a similar packaging had metal can and a glass lens.I remember a green soviet AL360 LED that was, actually, IR LED in a metal can + anti stokes phosphor that produced green light.Looks like this one:http://g777.ru/catalog/led_led_al/-412568/

author: CM800
author_rank: Frequent Contributor
timestamp: February 06, 2015, 06:56:04 pm
content: If it is a prototyped I wouldn't be surprised with them using an old package like that, It's cheaper and easier to prototype / develop with packages that used to be hand made, It wouldn't surprise me if they had an old machine that would be hand operated by people to build the old LED packages.
guess what this is for - Page 1
Forum section: electronics / projects

author: LootMaster
author_rank: Regular Contributor
timestamp: April 30, 2024, 06:00:51 am
content: what is this?

author: Smokey
author_rank: Super Contributor
timestamp: April 30, 2024, 06:18:16 am
content: Who's on first?

author: BennoG
author_rank: Frequent Contributor
timestamp: April 30, 2024, 07:23:17 am
content: My best guess is that it is a tool to get a moderators attention.

author: moffy
author_rank: Super Contributor
timestamp: April 30, 2024, 07:59:47 am
content: Quote from: Smokey on April 30, 2024, 06:18:16 amWhat's on second, and I dunno is on third.

author: max_torque
author_rank: Super Contributor
timestamp: April 30, 2024, 11:43:06 am
content: Is it cake?

author: themadhippy
author_rank: Super Contributor
timestamp: April 30, 2024, 12:25:04 pm
content: Its a thingamajig for a whatchamacallit

author: Psi
author_rank: Super Contributor
timestamp: April 30, 2024, 12:31:49 pm
content: Quote from: max_torque on April 30, 2024, 11:43:06 amThe cake is a lie!

author: pcprogrammer
author_rank: Super Contributor
timestamp: April 30, 2024, 03:49:31 pm
content: Quote from: Psi on April 30, 2024, 12:31:49 pmIt went through the portals

author: DavidAlfa
author_rank: Super Contributor
timestamp: April 30, 2024, 04:06:10 pm
content: Quote from: pcprogrammer on April 30, 2024, 03:49:31 pmPortal to banned user list
Guidance on Resistor Value Selection for Different Protocols - Page 1
Forum section: electronics / projects

author: KarthiAru
author_rank: Newbie
timestamp: December 27, 2024, 02:42:30 am
content: Hello everyone!I've been examining a schematic for a working product and have some questions about the resistor values used for different communication lines and components. Specifically, the schematic uses 220 ohms for UART, 120 ohms for I2C, 22 ohms for switch inputs, and 68 ohms for LED outputs. These components are connected to an STM32 MCU via a mezzanine connector, with the lines being approximately 100mm long.Are there standard guidelines or rules of thumb for selecting resistor values based on different protocols, or are these values typically determined through experimentation? I'm hoping to streamline my Bill of Materials and reduce the need for extensive testing. Any advice or insights would be greatly appreciated!

author: moffy
author_rank: Super Contributor
timestamp: December 27, 2024, 03:51:29 am
content: The series resistance is for surge/static protection, but the values are somewhat arbitrary in choice, long traces generally require lower values than short ones because of capacitance but that is very layout dependent. Higher speed busses require lower values because of faster transmission speeds/edges. The final choice is a compromise of speed, capacitance and fault voltage tolerance.
Guidance wanted - measuring nanoamps reliably  (with Dave's microcurrent) - Page 1
Forum section: electronics / projects

author: Puffin
author_rank: Unknown
timestamp: April 12, 2018, 10:07:38 pm
content: I'm working on a long-lifetime coin-cell powered design with a draw of 200-700nA and trying to measure the load using an EEVBlog microcurrent gold, but what I'm seeing is that the readings are varying quite a bit [+/- 100nA] just depending on how close to the bench I'm sat, and by up to -500nA if I put a hand near the DUT. My test leads to the microcurrent are short, but I've just got standard meter probes on the terminals leading to the meter -- using a Fluke 175 [Side note - I initially used the EEVBlog BM235 but it shows drops of 100-400mV if I move anywhere near the test leads! The Fluke doesn't twitch more than 20mV]I can take my readings at a distance, and thus get myself out of causing the influence, but the whole setup seems more sensitive to external influence than I expected in general anyway and I'd like to be sure the readings I'm seeing are actually sane [They're actually about 2x what I was expecting, but that may be correct...]So I'd appreciate suggestions for best practices for measuring such low currents and use of a microcurrent gold, especially down at nanoamp levels. I'm very much a noob at caring about these sort of low currents.TIA

author: timpattinson
author_rank: Contributor
timestamp: April 13, 2018, 02:26:19 am
content: Sounds like an EMI problem... Have you tried putting the whole thing in a big tin can? (~= Faraday cage)Turn off any fluorescent or LED lights? Turning your phone (in your pocket presumably) off?
Guide to get a buck converter to radiate - Page 1
Forum section: electronics / projects

author: schratterulrich
author_rank: Regular Contributor
timestamp: December 10, 2021, 06:42:25 pm
content: - Search for the node with the highest di/dtThis is the “VIN” net of a buck converter-Select Bypass caps to create a resonance with a high Q factorfor example use a 100 pF capacitor in parallel with a 15 nH ESL value of another capacitorIf an AC current source is placed at the switching converter, the VIN node would show the following voltage:-Make the VIN node an effective antenna. Solder a long wire directly to it and orientate it exactly opposite to the GND cable of the supply to build a dipole.That's it

author: T3sl4co1l
author_rank: Super Contributor
timestamp: December 10, 2021, 06:51:17 pm
content: I mean, the SW node is right there beside it..? It's not exactly hard to do, and also not terribly illustrative of whatnotto do when one wishes to avoid radiation.Tim

author: schratterulrich
author_rank: Regular Contributor
timestamp: December 10, 2021, 07:17:01 pm
content: I agree that you can't learn too much from it, but I was just curious if it was enough to jam a radio station.

author: MathWizard
author_rank: Super Contributor
timestamp: December 11, 2021, 01:01:13 am
content: So how much power does a small SMPS radiate for a given antenna ? I'll have to try that, see if it can block my parents radio. I have all kinds of radio experiments I've yet to fool around with, but my day job keeps me too busy this year.
Guitar Hero USB mic A/D specs? - Page 1
Forum section: electronics / projects

author: Circlotron
author_rank: Super Contributor
timestamp: August 10, 2020, 12:48:18 am
content: The title mostly says it all. Anybody know what they use as an A/D, or would there be some way of telling by looking at the ID string or data stream?

author: oPossum
author_rank: Super Contributor
timestamp: August 10, 2020, 03:19:20 am
content: Get the VID & PID from device manager (windows) or lsusb (linux) and google it.
GW Instek GDS-1102A scope. - Page 1
Forum section: electronics / projects

author: crite40
author_rank: Newbie
timestamp: October 29, 2012, 04:22:49 am
content: Good day all!Well I've just got one of these today. Goes pretty well, but just one annoying problem.Most Digital scopes can switch off their on screen menu so the whole display can bu used as with an Analogscope. There does NOT appear to be any way of doing this with the GDS-1102A!Has anyone solved this problem, or found a work-around?At 72 I need a nice big display, as you might imagine.Looking forward to some feedback.Regards.

author: tlu
author_rank: Regular Contributor
timestamp: October 29, 2012, 05:13:22 am
content: Hi crite40,This is probably built into their firmware so it may not be possible to switch the menu on the side off or hide it. You can send an email to where you got the scope from and ask them to kindly make that suggestion to the manufacturer so in the next firmware version update, it will get implemented.I have to agree with you that it really is annoying when a simple hide menu function is not implemented. This should be standard in all dso made today in my honest opinion.tlu
GW Instek GOS-620 schematic? - Page 1
Forum section: electronics / projects

author: Sylvi
author_rank: Regular Contributor
timestamp: September 23, 2018, 05:02:36 am
content: HiI have a GW Instek GOS-620 20MHz analogue oscilloscope that is six months out of warranty and I would like to get the schematic for it. Does anyone have one or know where to find one?Instek has discontinued this unit from what I understand, replacing it with its bigger brother which has a built in multimeter and component tester or other stuff.My scope has a problem in the vertical positioning for both channels. If there is a small sine wave (2-divisions peak-to-peak) in the lower half of the display and I sweep it upward using the vertical position control, the wave gets smaller until it is a flat line about three-quarters of the way up. If the sine wave is a bit larger, it will be okay at the bottom of the screen but as it is swept upward the top half distorts then clips.I suspect the problem will come down to a bad solder connection in the vertical offset circuit.I ordered a new DSO which might be here in a week or two, after which I can open up the Instek and work on it with impunity.

author: Zero999
author_rank: Super Contributor
timestamp: September 25, 2018, 03:52:17 pm
content: I can't help you with the schematic I'm afraid.Where did you buy it from and how long ago? It's possible you're still entitled to something under the consumer protection laws, in your area, even if the warranty period has expired.

author: MT
author_rank: Super Contributor
timestamp: September 25, 2018, 08:27:50 pm
content: https://elektrotanya.com/gw-instek_gos-620_gos-630.pdf/download.html
Gyro sensor for absolute angle detection - Page 1
Forum section: electronics / projects

author: davorin
author_rank: Unknown
timestamp: May 14, 2018, 01:45:33 pm
content: EHLO (o;Is there a gyro/acceleration sensor which can be used for detecting absolute angle of the sensor?I'm testing currently the LIS2DH from ST but the resolution is somehow low if I want to detect an angle at 1 degree resolution....or maybe I am using it wrong (o;

author: Gyro
author_rank: Super Contributor
timestamp: May 14, 2018, 01:52:29 pm
content: You might want to tap intohttps://www.eevblog.com/forum/projects/suggestions-for-high-resolution-tiltmeter-(inclinometer)-sensor/
Gyro sensor with wake-up - Page 1
Forum section: electronics / projects

author: davorin
author_rank: Unknown
timestamp: September 20, 2018, 08:27:06 am
content: EHLO (o;Is someone aware of a gyro sensor which could be waked up through a simple knock on it?Most I have seen need to be running, though they offer a low-power mode to detect xyz axis acceleration...but I would need a sensor which draws current in the range of few uA and generates an interrupt as soon acceleration is detected...Or any other idea how to wake up a circuit with knocking on it?Idea is to make a control knob which reacts on taps to it...kiitoksia (o;

author: cgroen
author_rank: Unknown
timestamp: September 20, 2018, 08:59:00 am
content: Do you mean gyro (measuring angular movement) or accelerometer (measuring acceleration) ?I use LIS3DH from ST for detecting single and double tap, works pretty good:https://www.st.com/en/mems-and-sensors/lis3dh.html

author: davorin
author_rank: Unknown
timestamp: September 20, 2018, 09:10:26 am
content: The same sensor I used for testing....What is your experience with power consumption and detecting movements?Not sure if the low-power mode would detect any taps on it when using 1Hz ODR....

author: cgroen
author_rank: Unknown
timestamp: September 20, 2018, 09:13:17 am
content: I use it for detecting movement (when rest of system is shut off). Power consumption is very low, datasheet has the numbers

author: davorin
author_rank: Unknown
timestamp: September 20, 2018, 10:09:05 am
content: But don't you need something to read out the sensor continuously to detect changes or does it by it self?

author: cgroen
author_rank: Unknown
timestamp: September 20, 2018, 10:11:22 am
content: Oh no,you set the threshold and time, and it detects the condition automatically. It can the raise an output to signal that condition to to the rest of the system (som of my devices uses this signal to turn on powersupply of the main processor, in other systems I use it to make a wakeup signal to the processor to wake it from Deepsleep)
H Bridge DC Motor controller with a BTM7710G - Page 1
Forum section: electronics / projects

author: jwhitmore
author_rank: Regular Contributor
timestamp: July 12, 2015, 08:02:03 pm
content: Maybe it's just me who, as a SW engineer is getting confused by a data sheet for this IC. The IC has two high side switches and two low side switches, which can be turned on and off in what ever way you like. The data sheet has a truth table for the output in Figure 3 which is fine but it never mentions anything about driving the low side switches. Then in figure 4 it gives a circuit for a motor drive and has the outputs from the high side switch externally connected to the output pin of the LOW side switch.Surely you don't get a H bridge by driving the High side switch inputs IH1 and IH2 but you also have to drive the low side switchs as well IL1 and IL2. So back to figure 3 and Table 3 which states that an 'L' in the truth table is a sink condition. That truth table should have low side values as well?Yeah simply confused by this chip.http://www.farnell.com/datasheets/1836132.pdf
H bridge doesn't draw any current from supply - Page 1
Forum section: electronics / projects

author: Dmeads
author_rank: Regular Contributor
timestamp: August 18, 2019, 02:24:12 am
content: Hi all! I am building my first H bridge for an spwm signal.You can see via the picture, but here is another description:I have an FPGA that generates the different duty cycles needed to make a sine wave. Data one in the pic generates one half of the wave while data 2 generates the other. The Verilog is solid, I highly doubt that is causing the issue.I have four irf724n mosfets with 10k ohm pulldowns at the gate, the load is connected across as in the pic.The trouble is, no matter what voltage supply I connect to the H bridge, the signal remains the same size and is very not sinusoidal. Also no matter the load it doesn't draw any current (or so small my meter can't read it).Any thoughts? Thanks!

author: ledtester
author_rank: Super Contributor
timestamp: August 18, 2019, 02:34:09 am
content: Maybe you should have pull-ups on the upper arms of the H-bridge?

author: Circlotron
author_rank: Super Contributor
timestamp: August 18, 2019, 02:44:50 am
content: If the upper mosfets are only being driven with +5v to the gates, same as the lower ones, then the sources of those upper mosfets will be lucky to rise to more than +2V. The gate drive for the upper mosfets gates needs to be referenced to their sources, not referenced to ground.

author: Dmeads
author_rank: Regular Contributor
timestamp: August 18, 2019, 03:17:54 am
content: got it working!not perfect but not bad either!thanks!!
H-Bridge driver question (TB6612FNG) - Page 1
Forum section: electronics / projects

author: hozone
author_rank: Regular Contributor
timestamp: March 28, 2020, 09:30:50 am
content: The TB6612FNG can drive up to 2 motors.I would like to use this IC to drive just one motor. I'm using A pins for the motor I'm driving, AIN1 AIN2 PWMA, AO1 AO2.What's about the B motor pins if i don't care about that motor? BIN1 BIN2 PWMB BO1 BO2Reading the datasheet attached (https://toshiba.semicon-storage.com/ap-en/semiconductor/product/motor-driver-ics/brushed-dc-motor-driver-ics/detail.TB6612FNG.html) I'm not sure if it's better to put the driver in "stop mode" or in "short brake mode" (Table: H-SW Control Function).More in general the motor OUTPUT in "stop mode" are "OFF", so i think no current flow through the mosfet, in "short brake mode" the bottom mosfet are "ON" and the motors pins are all connected to "GND".What do you suggest me?Thank you!
replacing single mosfet with h-bridge in buck converter - Page 1
Forum section: electronics / projects

author: hussamaldean
author_rank: Unknown
timestamp: December 14, 2018, 01:51:30 pm
content: Hi allI got this idea for replacing the single mosfet with H-Bridge for buck converter for research purposes and I am wondering what kind of topology shall I use ? because I am currently confusedis there a benefit from doing such thing or shall I do it and share the results with everybody ?Regards

author: t1d
author_rank: Super Contributor
timestamp: December 14, 2018, 03:47:54 pm
content: Is any of this what you need? I really can't tell, from what you posted. We need more details...https://www.google.com/search?q=h-bridge+buck+converter+circuit&client=firefox-b-1&tbm=isch&tbo=u&source=univ&sa=X&ved=2ahUKEwjS3trr1J_fAhUIY6wKHfY9DBwQsAR6BAgBEAE&biw=1280&bih=667

author: hussamaldean
author_rank: Unknown
timestamp: December 14, 2018, 03:49:52 pm
content: Quote from: t1d on December 14, 2018, 03:47:54 pmI just need to change the mosfet to H-bridge

author: hussamaldean
author_rank: Unknown
timestamp: December 15, 2018, 03:45:39 am
content: I modified the tittle and the post for hopping a better answersthx in advance

author: Kasper
author_rank: Frequent Contributor
timestamp: December 15, 2018, 04:48:22 am
content: Buck converters with 1, 2 or 4 switches:1 switch: basic buck. Requires switch (mosfet) and diode. Current flows through diode when switch open.2 switches: replace diode with 2nd mosfet. Body diode of mosfet acts as diode, also 2nd mosfet can be turned on so current flows through channel instead of diode and has increased efficiency. Care must be taken to include dead time to avoid shoot through.4 switches: 2 phase buck. 2 buck regulator circuits connected in parallel (inputs and outputs tied together) and one buck driven 180° out of phase from the other (interleaved). This greatly reduces ripple voltage and allows smaller/cheaper components since the current is shared across the 2 phases.H bridge has 4 switches in it so you might be able to use them for a 2 phase buck. On top of the benefits listed above, you also only need 1 switch package (with 4 switches in it). Which might be smaller, cheaper and more efficient.

author: hussamaldean
author_rank: Unknown
timestamp: December 15, 2018, 04:50:41 am
content: Quote from: Kasper on December 15, 2018, 04:48:22 amsounds great so farcould you please attach the 4-channel mosfet for the buck converter ?I will appreciate it so much and thx in advance

author: Kasper
author_rank: Frequent Contributor
timestamp: December 15, 2018, 05:02:08 am
content: If you search for "2 phase buck" you should find lots of info.

author: hussamaldean
author_rank: Unknown
timestamp: December 15, 2018, 01:26:14 pm
content: Quote from: Kasper on December 15, 2018, 05:02:08 amwell, I will test bunch of circuit and update this postthx
H-BRIDGE schematics - Page 1
Forum section: electronics / projects

author: reviser
author_rank: Newbie
timestamp: September 26, 2013, 01:39:13 pm
content: I'm developing an h-bridge to control the speed and direction of rotation of a DC motor.The motor I need to control is 24V 10A.I've created a schematic for the the h-brigde but I'd like to hear some opinions about the overall schematic and/or the specific components I've selected.Any suggestion is welcome.

author: Bertho
author_rank: Regular Contributor
timestamp: September 26, 2013, 04:28:12 pm
content: Don't use 1N4007 diodes. They are not designed for use in these type of circuits. You need a few high-speed/fast-recovery diodes. Otherwise you'll start to push the output voltage back into the lower voltage supply (and that really sucks if you are switching a few hundred volts at the output). I'm also not sure you need that much capacitance on the Vb trampoline.

author: Kremmen
author_rank: Super Contributor
timestamp: September 26, 2013, 05:01:43 pm
content: The bootstrap diode should indeed be a fast low leakage type, which 1N4007 is not. The main reason to have a low leak diode is to preserve the charge of the bootstrap cap for the high side switch, in case there is a prolonged continuous on-time. For the gate discharge diodes you may want to consider something more appropriate as well. 1N4148 would be a jelly bean that should work OK.Note that for motor control you don't need to switch both sides of the bridge, one side can be on constantly while the other is modulated. Independent control of all the switches allows you to additionally control the circulating current in the motor, for braking purposes.Also, you may want to consider measuring and controlling the motor armature current. A 10 amp motor would take considerable current under stalling conditions. The traditional way is to measure the bridge voltage from the low side common leg and control modulation as needed.Recommended reading: IR app note 987 athttp://www.irf.com/technical-info/appnotes/an-978.pdf
h-bridge - Page 1
Forum section: electronics / projects

author: odell
author_rank: Contributor
timestamp: August 20, 2012, 05:10:29 am
content: can you use h-bridge on a pc fans? I like to control a fan air flow direction. so if in need more air going in. I can change the direction for the fans

author: IanB
author_rank: Super Contributor
timestamp: August 20, 2012, 05:23:11 am
content: Why don't you find out? If you have an old fan you are not too worried about damaging, try reversing the polarity on the input wires and see what happens. Just use a small 9 V battery and touch the wires briefly. (You can guess from this that I don't think it will work and a small 9 V battery will minimize the risk of letting the magic smoke out.)Also, the fan blades are curved and are designed to move air in one direction only. If you examine them closely you can see this. If you did manage to make the fan run in reverse it wouldn't move air very well.

author: EEMarc
author_rank: Regular Contributor
timestamp: August 20, 2012, 06:23:53 am
content: Most computer fans are not DC motors. They are AC motors in disguise with and on board AC motor controller that accepts DC voltages. They call them brushless DC motors as a marketing stunt to try to avoid losing customers scared away from the fact that it is an AC motor. It worked. The reason they are brushless and don't need a commutator is because the AC motors have a motor controller that take care of the switching requirements.Reversing the fan blade may or may not be possible depending on the design of the motor controller. It may work, it may work poorly, or it may not work at all.The fan blades themselves as IanB pointed out are designed for one direction and would not reverse well.You really need a fan that is designed for bidirectional operation.

author: G7PSK
author_rank: Super Contributor
timestamp: August 20, 2012, 08:55:10 pm
content: Stack two fans back to back, turn one on for out flow and the other on for in flow, all the computer fans that I have used are polarity conscious and wont work with reversed current flow. Further the price of computer fans is such that the circuitry to do the reverse will cost more than the fan.
hack a hp colour loaserjet  cp1515n printer - Page 1
Forum section: electronics / projects

author: m3vuv
author_rank: Super Contributor
timestamp: December 15, 2019, 02:30:49 pm
content: Hi all,im having issues doing laser transfer pcb iron on method,long story short,i refilled my black toner cartdrige,ever since the transfer method seems crap,its like there isnt enough toner gets layed onto the print,is there a wat to increase the amount of toner that gets printed?,its as if the toner is diluted,ive tried all settings but its the same,it was fine before the refill.,thanks in advance,m3vuv.

author: Messtechniker
author_rank: Frequent Contributor
timestamp: December 15, 2019, 02:43:49 pm
content: Not all toner is the same as you have found out.Toner material differs as to a number of parameters likegrain size, flow capability or melting point, just to mention some.You will have to experiment to find the right type of refill tonerfor you specific printer.

author: Bud
author_rank: Super Contributor
timestamp: December 15, 2019, 03:42:53 pm
content: When i was making my boards i realized fast that refilled toner did not work, i had to buy new cartridges.

author: m3vuv
author_rank: Super Contributor
timestamp: December 15, 2019, 04:59:55 pm
content: yup the trouble is tho,im sure they are about £100 a pop!
Hack Bosch ABS for off-road use - Page 1
Forum section: electronics / projects

author: rvalente
author_rank: Frequent Contributor
timestamp: April 09, 2021, 04:17:09 pm
content: Hello Mates,I own a 85 Engesa Jeep, quite similar to a Wrangler or so. This vehicle has a very little weight over the rear axle and is very common to the rear wheels lock before the front reaches the maximum breaking capacity.I've done a small research and the best candidate to install would be the Bosch ABS 8.1 (0 265 956 008) from a donor Ford Ranger, due to access to wiring schematics and easiness to get on the scrapyard.The thing is: the car won't have ford can to communicate them I'll always get a code.Is there any configuration tool or may to reflash a bosch 8.1 or 9.0?I wish I could affoard a bosch motorsport M4 abs but, meh, whats the fun in that?

author: coromonadalix
author_rank: Super Contributor
timestamp: April 09, 2021, 05:26:46 pm
content: you should go in car related forums ??

author: rvalente
author_rank: Frequent Contributor
timestamp: April 09, 2021, 05:37:16 pm
content: i've tried, guys there know how to take dumps, modify them and reflash, not much beyond

author: coromonadalix
author_rank: Super Contributor
timestamp: April 10, 2021, 12:18:41 am
content: Some problems are the peripherals like the abs traction control systems etc .... are sometimes serial matched in the main ecu ... meaning you can not fit or make it work until the "Brain" accept themYou'll need the softwares and jbod adapters etc ...On my Suzuki SUV, everything is serial coded and entered in the ECU, even if i change my abs pump for the same part, it will not work ...

author: james_s
author_rank: Super Contributor
timestamp: April 10, 2021, 12:23:34 am
content: The older the system, the more standalone they tend to be. I know the Bosch ABS in my Volvo is more or less standalone, it has a separate control box and takes signals from the brake light switch and speedometer IIRC. A good place to start is the service manual for the prospective donor vehicle.

author: mvs
author_rank: Frequent Contributor
timestamp: April 10, 2021, 01:01:41 am
content: Quote from: rvalente on April 09, 2021, 04:17:09 pmYes, but i would assume it is not that critical for an off-road vehicle.ABS is an important system and should work w/o CAN bus in basic mode. Bus failure is not that uncommon malfunction.Advanced features of ABS unit, like ESC, TCS, EDL do rely on CAN communication and a bunch of additional sensors, so they would not be available anyway.