hybridfree/eevblog-posts huggingface dataset:
Update grinder switch - Page 1
Forum section: electronics / beginners

author: fixit7
author_rank: Regular Contributor
timestamp: July 01, 2019, 12:59:24 am
content: I am updating my work area.I want to replace this switch with something more durable.I feel it is a poor design.I hooked it up using a wall switch to turn it on and off.Can someone please help me with something more durable.

author: bob91343
author_rank: Super Contributor
timestamp: July 01, 2019, 01:43:17 am
content: Look at the nameplate of the motor to see the switch rating required. Once you have that, buy any switch that will fit that has that rating.You will have to fabricate a plate to mount the switch in place of the old one. Unless you are lucky enough to find a switch that can mount in the same hole as the old one.There are no special requirements. A toggle switch would work well; my grinder has a slide switch. Amazingly, that has never failed in all the years I've owned it, and it's a really cheap switch. I dislike slide switches; often they get difficult to operate and are prone to an insecure connection. But the manufacturers love them due to their almost no cost.

author: fixit7
author_rank: Regular Contributor
timestamp: July 01, 2019, 02:10:55 am
content: 4 ampsI found this.https://www.amazon.com/Gardner-Bender-GSW-110-Electrical-Terminal/dp/B00004WLK6/ref=sr_1_36?keywords=10+amp+ac+switch&qid=1561947300&s=gateway&sr=8-36

author: bob91343
author_rank: Super Contributor
timestamp: July 01, 2019, 02:28:22 am
content: That should do it!

author: Ysjoelfir
author_rank: Frequent Contributor
timestamp: July 01, 2019, 12:23:55 pm
content: I have to admit that I would trust that ancient clunky push/pull switch far more than a small toggle switch. Also it serves a dual purpose as an emergency stop by just having to hit it to stop the machine.

author: DTJ
author_rank: Super Contributor
timestamp: July 01, 2019, 12:46:00 pm
content: A simple light switch?https://www.bunnings.com.au/deta-single-architrave-switch_p4430440

author: rstofer
author_rank: Super Contributor
timestamp: July 01, 2019, 03:25:25 pm
content: It should be no surprise that switches intended to control motors will have a HP rating in addition to a voltage/amperage rating. Cheap light switches don't usually have a HP rating but the more expensive switches do have such a rating.I can't read the markings on that toggle switch... It looks like it might be rated for 3/4 HP but I'm not certain of that.Remember the high inrush current when starting the motor is at least 6 times nameplate. Grinders usually have a lot of mass so they are slow to accelerate. As a result, the starting current diminishes over a relatively long time.

author: DTJ
author_rank: Super Contributor
timestamp: July 02, 2019, 12:26:04 am
content: Quote from: rstofer on July 01, 2019, 03:25:25 pmThat's all true - I thought the grinder looked like a light duty one.I'd probably use a cheap light switch (and have done in the past on a drill press) but you are correct, it's probably not best practice.
Upgrade path from ATTEN 936 - Page 1
Forum section: electronics / beginners

author: technix
author_rank: Super Contributor
timestamp: September 15, 2015, 01:23:28 pm
content: This is yet another soldering iron post.So I acquired the ATTEN 936, which is a Hakko 936 clone. There is going to be a time that my needs outgrow it. So what is my upgrade path? Should I try and roll my own control board (probably with USB or Bluetooth-based digital control) while still using some part of the ATTEN station?Bear in mind that any genuine Hakko soldering stations sells at at least 3x the price of the clone, and rolling my own board will cost about the same as my current soldering station.

author: Monkeh
author_rank: Super Contributor
timestamp: September 15, 2015, 01:38:06 pm
content: The upgrade path is to jump straight out of conventional heaters and into the world of RF (Metcal, Thermaltronics, Hakko) or integrated heater (JBC.. others?).Anything else is just polishing.

author: TorqueRanger
author_rank: Frequent Contributor
timestamp: September 15, 2015, 02:44:08 pm
content: There are reasons why clones are so much cheaper ... I would get a Hakko FX-888D or find a used Metcal .. I have the hakko for right now .. Don't get me wrong I would a Metcal or JBC but that's alot of money to put out for beginner like me and the hakko does everything I need and more..

author: thefamilyman
author_rank: Regular Contributor
timestamp: September 15, 2015, 08:36:28 pm
content: Have a look at the Hakko FX-95x series. I have a FX-950 that uses the T12 heater element tips system, its slim, easy to use, powerful and won't cost you the earth. I also personally like the good old a look analog knob rather that digital buttons.

author: GreyWoolfe
author_rank: Unknown
timestamp: September 15, 2015, 11:09:35 pm
content: Quote from: thefamilyman on September 15, 2015, 08:36:28 pmI have the FX-951, upgraded from a Hakko 936. The knob was nice but I like the standard issue auto sleep cradle (optional on the 950) and auto shut off. I had a bad habit of leaving the 936 on even after adding a power LED. The price was acceptable with the TEquipment.net EEVblog discount. The best price, after a quick look, was $242.00 on eBay ( hope it's not a fake) for the 950. I was all in at $287 with 5 tips and tip holders and 1 extra brass curl w/free shipping from TEquipment.
Upgrading an old Woods "Dialomatic" battery charger - Page 1
Forum section: electronics / beginners

author: shtonkalot
author_rank: Newbie
timestamp: March 05, 2019, 09:46:39 am
content: Hi all. Just wondering on the possibility of upgrading an old "dumb" battery charger to a 3 stage type with different battery chemistry options for the voltages.I was hoping to find some projects similar already done online to try copy and or modify but my google-fu has turned up nothing useful.Anyone done something like this? Anyone know how to do it or why not to try?
Upgrading Rigol MSO1104Z to unlock options - Page 1
Forum section: electronics / beginners

author: legacy
author_rank: Super Contributor
timestamp: November 30, 2016, 10:57:52 am
content: is it possible ? anyone has already tried ?

author: legacy
author_rank: Super Contributor
timestamp: November 30, 2016, 06:26:25 pm
content: foundvideo
Upload a program to FPGA on OSX - Page 1
Forum section: electronics / beginners

author: mathk
author_rank: Contributor
timestamp: April 19, 2012, 10:17:31 pm
content: I have recently get a hand on a Pailllio FPGA board and I must admit that I am totally a noobs about FPGA. So I would like to get it work on OSX. After some reading on internet I have founded that OSX is not really a good platform for that but still I would like to have a try. I can always fall back to a Linux VM.So my question is what is the process for uploading a vhdl or verily program?I have been able to compile and install icarus and also the papillio loader but apparently when I try to target fpga with icarus I got the folioing error:Code:$ iverilog -t fpga -o hello.bit test.vERROR: Unable to read config file: /usr/local/lib/ivl/fpga.confSo I am wondering if I did not miss a stepThanks

author: benemorius
author_rank: Regular Contributor
timestamp: April 19, 2012, 10:53:16 pm
content: Well I don't have the answers you're looking for, but it appears fairly obvious that specifying "-t fpga" causes it to look for a file at /usr/local/lib/ivl/fpga.conf. Maybe the file is supposed to be there and it isn't. Maybe the file is there but can't be read or parsed for other reasons. A good first step would be investigating the existence of that file.That file path isn't where you'd expect to find user-editable configuration files, so it likely contains hardware definitions or the like. It may be that you need to install additional packages or compile the software with additional switches in order for this file to be there. Or perhaps you need to specify something other than fpga. You could see what files do exist in that directory and try one of them instead (perhaps there's an fpga2.conf or an FPGA.conf).

author: joelby
author_rank: Frequent Contributor
timestamp: April 21, 2012, 04:33:08 pm
content: Unfortunately Icarus doesn't know anything about (proprietary) Xilinx FPGAs. The only way you can generate working bit files is to use the Xilinx tools, and this means using Windows or Linux.
Upload ESP32-CAM pictures to...?  - Page 1
Forum section: electronics / beginners

author: YurkshireLad
author_rank: Frequent Contributor
timestamp: April 08, 2021, 11:25:46 pm
content: I have a simple sketch for an ESP32-CAM module that is connected to an RWLC-0516 motion sensor. The code monitors the sensor and automatically takes a picture when motion is detected.I don't know what to do with the pictures. I have a wyze camera at home that sends a notification plus a picture to my phone when it detects motion. The pictures are available on my phone wherever I am.I could automatically email pictures from my ESP32-CAM to myself, but I'd need a SMTP service that I could use at no cost, so there's probably a limit on the number of emails I can send.I could automatically upload the pictures to a website, but I'd have to set one up that accepts private uploads but also uses user accounts so only my wife and I can access the pictures.I could try to upload them to something like Google photos, or OneDrive but I need to easily be able to delete them from a phone.If I upload the pictures somewhere, I'd like them to be automatically deleted if they're too old.Has anyone done something like this?

author: JustMeHere
author_rank: Frequent Contributor
timestamp: April 09, 2021, 12:15:21 am
content: You can run postfix.You will need a service like dynu.com to relay the emails.
Upload image - Page 1
Forum section: electronics / beginners

author: WiredSmart
author_rank: Contributor
timestamp: December 12, 2022, 06:17:27 am
content: How do you upload images the easiest way on eevblog . Im stuggling

author: Jackster
author_rank: Frequent Contributor
timestamp: December 12, 2022, 06:33:36 am
content: When posting a new topic or reply, click on a the attachments link, them choose file.Embedding the photos into the text area is hit and miss.Personally I usehttps://postimages.org/if I have many photos. Upland your photos and then copy the forum code and paste it into the editor.

author: pcprogrammer
author_rank: Super Contributor
timestamp: December 12, 2022, 07:00:56 am
content: Quote from: Jackster on December 12, 2022, 06:33:36 amYes, this is how to upload images here. Max 10 per post and limited to so many megabytes per image and in total.Quote from: Jackster on December 12, 2022, 06:33:36 amAlso correct, but there are ways to do it with not to much effort. Simply upload your images when making the post and then use the "modify" button to edit your post, but do it in a new tab. (right click on the button and select open in new tab)Then use the embed image button to place your image in the text where you want it. (Button next to the insert hyperlink button in the formatting section of the editor) Go to the other tab and copy the link of the image you want in the created image space and paste it between the [ img ] [ /img ] markers. (spaces added here to make them visible as text)Save your edited message and it is done. When done quick enough you won't get the "Last edited" message.Quote from: Jackster on December 12, 2022, 06:33:36 amThis has been advised against many times because it can break posts when the used image platform goes bust or the images are lost otherwise. Your post looks silly then without the photos.Also consider to resize your images to not take up to much screen space and make sure they are not to big in data size. A lot of forum users are still on slower connections and are hindered by the slow loading images.

author: bidrohini
author_rank: Regular Contributor
timestamp: December 13, 2022, 07:06:39 am
content: Kindly follow the image that I have attached.
upping battery voltage on old pentax AF160 flash - Page 1
Forum section: electronics / beginners

author: Simon
author_rank: Unknown
timestamp: April 30, 2014, 07:39:13 pm
content: I have an old pentax AF160 flash unit. It runs on 2x AA's. I was thinking what is i use a 1.2V NiMH and a 3.6V Li-Ion, that would give me 4.8V instead of 2.4V, the unit will have been designed for up to 3.5V I expect as it would have originally taken alkalines. Is it worth the risk ?I'm hoping for faster recharge times.

author: jlmoon
author_rank: Unknown
timestamp: April 30, 2014, 08:03:30 pm
content: only if you don't mind letting the magic smoke out of that smps power supply. Think you could have a problem with inrush current along with the sudden much lower internal resistance of those new batteries. You are doubling the input voltage, not to mention the current to that device, don't think the engineers had that much tolerance in mind.

author: Simon
author_rank: Unknown
timestamp: April 30, 2014, 09:27:25 pm
content: bearing in mind 2x alkalines are up to 3.3V I'm looking to go to 4.8V

author: SeanB
author_rank: Super Contributor
timestamp: May 01, 2014, 05:44:23 am
content: It will cook. Just use 3 NimH cells and it will charge faster. The limit is the teeny tiny little transformer inside that has resistance you cannot do anything about. Higher voltage and they will melt the windings into a charred mass. If you want faster charging get a new flash unit.

author: Simon
author_rank: Unknown
timestamp: May 01, 2014, 06:31:58 pm
content: I was contemplating as to whether the guts were made to work universally off 3 or 6 volts as many flashes took 4 AA's.
UPS and ESD monitor puzzle - Page 1
Forum section: electronics / beginners

author: openthomas
author_rank: Contributor
timestamp: October 07, 2012, 12:00:15 pm
content: So I have a 3m 724 esd workstation monitor. To monitor a antistatic mat the unit requires 2 grounds, one from the socket and another soft ground from say a radiator. You connect the soft ground to the mat, and from another connector on the mat back to the monitor.I connected the 724 monitor through my ups socket and the soft ground to a radiator, but the alarm shows that the mat is not grounded. However when I switch and connect it directly to the socket, the grounds appear equal and the alarm goes out. Why ? Why does the ups not pass ground ?

author: SeanB
author_rank: Super Contributor
timestamp: October 07, 2012, 12:50:54 pm
content: It should, but often this fault is not noticed, or the wire is left off to cut cost. You would have to open the UPS and check the wiring to be sure.

author: amyk
author_rank: Super Contributor
timestamp: October 07, 2012, 12:56:36 pm
content: Quote from: SeanB on October 07, 2012, 12:50:54 pmA DMM also works for checking ground continuity...

author: openthomas
author_rank: Contributor
timestamp: October 07, 2012, 03:17:20 pm
content: I just run a continuity check from ground in the wall socket to ground on the UPS socket ? Safe ?

author: Monkeh
author_rank: Super Contributor
timestamp: October 07, 2012, 05:32:24 pm
content: Quote from: openthomas on October 07, 2012, 03:17:20 pmWhy wouldn't it be?
UPS and solid state relays - Page 1
Forum section: electronics / beginners

author: spicey
author_rank: Newbie
timestamp: January 21, 2022, 01:21:23 pm
content: For years I have had an APC UPS with 5 Song Chuan 832A series relays (24VDC 30A SPDT 5p). In the last month I am experiencing many power problems in my area and the relays sound so many times that it is quite annoying. Do you see feasible to replace them with solid state relays to avoid the noise? what solid state relays may I use to replace the old ones? Thanks in advanceSong Chuan 832A relays (Mouser):https://www.mouser.com/datasheet/2/378/201711289352991617-2307139.pdf

author: rpiloverbd
author_rank: Regular Contributor
timestamp: January 21, 2022, 01:49:52 pm
content: If you want to use this board, you must use the same relay. SSR has a different pinout and PCB footprint, if you want to use SSR, you will need to redesign and remake the board completely.

author: spicey
author_rank: Newbie
timestamp: January 21, 2022, 04:54:31 pm
content: Ok, thanks for your comment but the footprint of the relays is not an issue and there is plenty of space inside the UPS to add mods. Let's say I design some daughter boards for SSR that mimic the footprint of the original EMR (electromechanical relays). What would be the ideal SSR to use as a replacement? Would this be possible? Can a modern SSR provide electrical isolation comparable to an old EMR?
UPS circuit based on 18650. Need your advice. - Page 1
Forum section: electronics / beginners

author: r4r
author_rank: Contributor
timestamp: July 24, 2019, 06:26:41 pm
content: Hi!Trying to build some kind of UPS. What do you think about schematic?I'm not quite sure about NCP380 as current (charge) limiter...Thank you!
UPS suddenly started oscillating between mains and inverter (it popped). - Page 1
Forum section: electronics / beginners

author: vgamesx2
author_rank: Regular Contributor
timestamp: September 24, 2022, 01:24:14 pm
content: The title sums up everything, I was standing around not doing much when my UPS started making TikToks with the relay, I was trying to troubleshoot/reset it to figure out if it was just being silly when one or more capacitors have guaranteed blown and it started smoking, I quickly disconnected it and the battery, thankfully no flames or anything dramatic but do guys you have any idea what would've caused that to happen?

author: kjr18
author_rank: Regular Contributor
timestamp: September 24, 2022, 04:21:53 pm
content: Probably constant power cycling caused by not stable supply. It also depends on what type of UPS it was, online or offline. Offline starts supplying from battery when mains disappear, online runs all the time. They also can normalise to some extent output voltage, by connecting different taps to output transformer, at least mine was doing it.

author: james_s
author_rank: Super Contributor
timestamp: September 24, 2022, 04:33:09 pm
content: I'd bet bad capacitors are the root cause of the issue. Bad cap causes the internal power supply to be unstable and confuses the UPS.

author: vgamesx2
author_rank: Regular Contributor
timestamp: September 24, 2022, 05:33:00 pm
content: Quote from: kjr18 on September 24, 2022, 04:21:53 pmNope, I can confirm we actually have fairly stable power here, it's fairly rare to be bad enough to trip a UPS much less full outages and surprisingly even surges have been a non-issue, can't remember one ever taking out any unprotected equipment.Quote from: james_s on September 24, 2022, 04:33:09 pmYeah, that's what I was thinking, wasn't sure and I don't want to open it right now though.

author: Vovk_Z
author_rank: Super Contributor
timestamp: September 25, 2022, 09:27:31 am
content: Bad electrolitic caps are reason #1, because it is usually hot inside UPS.And if UPS is old enough it may need to 'recap' relays too. Dead relays is reason of UPS fail number two.
UPS transformer two primaries - Page 1
Forum section: electronics / beginners

author: Mario_33
author_rank: Newbie
timestamp: March 18, 2021, 05:29:00 pm
content: Hello! I salvaged a transformer from an Mustek PowerPro 800 UPS but couldn't check the board. I would like to make a 12v linear PSU. The transformer has two primary windings and one secondary winding. After checking the resistance of windings got: first primary - 9.5ohm, second primary 1.1ohm, secondary 1ohm. When I connect the 240v to the first primary the secondary output is about 15v(which I think is fine). If I check the second primary in this case it gives about 22v (while input on first primary is connected to 240v). Found nothing on google about this UPS or this type of transformer. Does anyone know what is the role of this second primary?Thank you in advance!

author: mvs
author_rank: Frequent Contributor
timestamp: March 18, 2021, 06:18:00 pm
content: Two primary windings could be used as autotransformer to step up or step down output voltage by 22V.

author: Mario_33
author_rank: Newbie
timestamp: March 18, 2021, 06:29:48 pm
content: Thank you for your reply. But shouldn't it be a tapping transformer with only one primary and many wire as inputs on the same windings(I have seen this transformers on other UPSes, for 180v 200v 220v and 240v all in the primary)? Can it be that the second winding is used by the board to check the polarity?

author: mvs
author_rank: Frequent Contributor
timestamp: March 18, 2021, 10:47:56 pm
content: Quote from: Mario_33 on March 18, 2021, 06:29:48 pmYou can use a single winding with multiple taps or multiple windings to make an autotransformer. It depends on the designer and perhaps cost calculation.QuoteIt is AC voltage, so there is no polarity, but perhaps phase detection/sync or they have used it as auxilary supply for electronics, perhaps even battery charger. However UPS usually use normal secondary winding to charge the battery.

author: Mario_33
author_rank: Newbie
timestamp: March 18, 2021, 11:31:33 pm
content: Thank you very much for the detailed explanation 😁. You were very kind!

author: golden_labels
author_rank: Super Contributor
timestamp: March 19, 2021, 12:27:17 am
content: While salvaging components without datasheets, either store the whole board or document their surroundings (photos, a sketch for more obvious circuits). Without that it will be very hard to tell what are characteristics of the part or even how to use it. In particular for elements that are often application-specific, like transformers. In this case knowing, how it was connected, would tell much about it.Could it be that the primary windings were used alternatively for either charging battery and on-line operation?

author: Mario_33
author_rank: Newbie
timestamp: March 19, 2021, 09:55:16 am
content: Yes you are right, but sometimes we forget these things or can't get all the info and have to do it the hard way. Thank you very much!
UPS trouble-shoot - Page 1
Forum section: electronics / beginners

author: sam1275
author_rank: Frequent Contributor
timestamp: July 25, 2018, 02:15:35 pm
content: Hello.There is an UPS that stopped working when no one's around, when we checked it later, we found it would not power on. The 12v battery is only 4v, but the wall socket is supplying power.We didn't find anything burn or wrong after took it apart, but it must be broken somewhere, otherwise the battery would not be drained to that low even if the wall power was out.We don't have a spare battery now, but would a healthy UPS turn on without a good battery(but with wall power only)?Also what will be the most possible reason for it to broken?Thanks.

author: Bratster
author_rank: Frequent Contributor
timestamp: July 26, 2018, 01:39:00 am
content: Quote from: sam1275 on July 25, 2018, 02:15:35 pmUPS' generally will not power up if the battery is dead.if this UPS is over a year old it's possible that it just killed the battery by overcharging it and then there was finally a power outage or got unplugged or something and was not able to restart cuz the battery was dead.Sent from my Fi Moto x4 using Tapatalk

author: bitseeker
author_rank: Super Contributor
timestamp: July 26, 2018, 04:52:40 am
content: Yeah, most UPS won't start with dead batteries. It's possible that the charge circuit died, but change the batteries first. Then, you'll be able to tell if anything else is awry.
Mods Please Delete - Page 1
Forum section: electronics / beginners

author: Simon_RL
author_rank: Regular Contributor
timestamp: April 17, 2020, 01:33:34 pm
content: Thread re-posted in Repair section. It seemed a more appropriate place to put it.

author: ozcar
author_rank: Frequent Contributor
timestamp: April 18, 2020, 08:31:45 pm
content: So it is push-on push-off, DPST, and PCB-mounting, but also has mounting plate? The ones in the Ebay listing look like the holes in the mounting plate are unthreaded but I'm not sure. Any flexibility in that - eg does it really need the mounting plate?Maybe try the places that sell parts for TVs etc, like WES Components.

author: Simon_RL
author_rank: Regular Contributor
timestamp: April 19, 2020, 08:32:39 am
content: Quote from: ozcar on April 18, 2020, 08:31:45 pmThanks Oscar. On my oscilloscope they used the mounting plate to attach to the chassis which is earthed. The switch poles are wired to live and neutral for Vac in and then feeds into the power supply.I have checked WES, they have switches in similar form factor, but not the same spec.
Urgent: STM8S003F3 reset pin gets damaged - Page 1
Forum section: electronics / beginners

author: Vindhyachal.takniki
author_rank: Frequent Contributor
timestamp: December 05, 2014, 01:46:03 pm
content: I am using STM8S003F3 & attached is circuit.I have connected some switches in pull-up configuration as shown.After some correct operations, I have seen that some of boards stopped working.It was problem 1 as below in damaged boards & problem 2 in one of damaged board.1. On debugging, I had checked that voltage at reset pin is around 2V.This keep the device in reset state & won't allow running.I don't understand why this is happening. All the voltages that I have applied are within range.I have also removed the RC network across reset pin, but still pin is showing 2V approx.What could be possible reason?2. On one of switch pin, either I give 0V or 5V, software always read zero.However when I configure same pin as output, I am able to toggle the pin.But as soon as configured as input, it always read zero.All other switches are working fine i.e can read them properly.What could be possible reason?3. Board works fine for some operations but suddenly reset pin problem occur after that.

author: Andy Watson
author_rank: Super Contributor
timestamp: December 05, 2014, 03:43:50 pm
content: What does NRST attach to on J2 ? Is there any possibility that a voltage outside the range 0 to Vdd can be imposed on the input?

author: Vindhyachal.takniki
author_rank: Frequent Contributor
timestamp: December 06, 2014, 08:38:26 pm
content: I had removed 10K resistor across reset, now module is working from last 2 day.However I will check for 3-4 days before conclusion.

author: wraper
author_rank: Unknown
timestamp: December 06, 2014, 11:27:38 pm
content: Why PC6 and PC7 are connected to GND through 0R resistors?
USART confusion - Page 1
Forum section: electronics / beginners

author: allanw
author_rank: Frequent Contributor
timestamp: November 06, 2010, 01:21:19 am
content: I'm a little confused by how USART works. I'm trying to interface an ARM Cortex-M3 with an XPort Pro for serial->ethernet.Do I only need to connect the RX and TX lines? There's also a clock line which I'm guessing is for synchronous mode. And CTS and RTS. What's the best way to hook up these two devices together? They're on the same board, not discretely wired.I ask because the docs for the Xport Pro seem to imply that CTS/RTS/DTR are optional (and there is no clock signal)http://www.lantronix.com/pdf/XPort-Pro_IG.pdfpage 8

author: EEVblog
author_rank: Unknown
timestamp: November 06, 2010, 02:31:06 am
content: Quote from: allanw on November 06, 2010, 01:21:19 amCorrect. You only need TX, RX and GND to implement what's called a software handshake null modem interface. This is very common (the most common these days?)The other lines are used for what's called hardware handshaking between the two devices.Maybe some more info here:http://www.beyondlogic.org/serial/serial.htmDave.
USB (5.0V) pass through UPS for portable gear? - Page 1
Forum section: electronics / beginners

author: Purduephotog
author_rank: Regular Contributor
timestamp: July 08, 2020, 11:33:42 pm
content: No, I don't want a battery pack...We've been dealing with a number of power outages recently. I'm looking to find something that offers 'standby' USB power for devices, but is also intelligent enough to know you don't charge the battery and pull power at the same time. I don't believe it's needed to be the full up power-conditioning UPS I used to use in computer centers, but something similar would be nice.And I"ve looked, but everything points to a battery pack.The TP4056 is my favorite miniature charger... and with a couple of resistors (as you all know) you can set the current wherever and however. And since it doesn't 'trickle' but actually shuts off (at least it did) then it's safe to charge up a battery and let it sit there. It then needs a circuit to produce 5V to feed the device, but that's still fairly easily done.But what isn't or what has been causing me angst is the 'always on' and 'switch' that would detect the loss of power and swap over to the boost circuit from the battery.And I don't want to be running both at the same time- aka 'charging' the battery while 'draining' the battery to power the device.So, anything out there? Any magic switching circuits? I've used boards from Mini-box.com before and been very happy- the pico-UPS worked nicely, but it gave me trouble in design as it needed exactly 12V, so an extra circuit. There was a wide-voltage one at one time but the upper voltage limit was around 15.6V.... which again, defeats the purpose of having everything micro-usb 5.0VThanks kindly.

author: kjr18
author_rank: Regular Contributor
timestamp: July 09, 2020, 01:44:49 pm
content: I made something like that some time ago. It looked like this:All you need is one P-channel mosfet, one diode and one gate resistor. At least it worked for me.

author: Chalcogenide
author_rank: Regular Contributor
timestamp: July 09, 2020, 02:29:15 pm
content: I made a similar circuit with a TPS2113A (Auto-switching power MUX), a chip which allows to automatically select between two input sources to provide power to the output. I have one input connected to the USB port and the second input connected to a boost converter always providing 5 V. However, if USB power is detected, the TPS chip will choose the USB voltage, because you can set a sort of "priority" with a resistive divider, and seemlessly switch over to the boost supply if the USB voltage falls below the setpoint. There might be a ton of cheaper solutions, but this works and it's trivial to implement. I have found the inrush current limit to be kind of picky and to cause more issues than it should solve, so I just disabled the current limit by shorting the Ilim pin to ground.
USB 2.0 Microscope to USB 3.0? - Page 1
Forum section: electronics / beginners

author: Falcon69
author_rank: Super Contributor
timestamp: March 19, 2014, 04:47:53 am
content: Okay, I saw a thread here that discussed 2.0 USB Microscopes not being able to do live video in real time for a larger display. It lags do to not being able to transfer data between the camera and the computer because of the 2.0 limitation.I can't find that thread now, so...Anyway, I had just bought thishttp://www.ebay.com/itm/380777496580?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649Is it possible to take it apart, grab the wires from the camera, and somehow make a small circuit to convert that signal to USB 3.0? Like maybe the analog signal from the camera (like RCA's or something) plugged into a module which converts that data to USB 3.0 and sends it to the computer.Any ideas? I tried searching for something and couldn't find it. All I can find are from RCA to HDMI.

author: jeremy
author_rank: Super Contributor
timestamp: March 19, 2014, 05:05:39 am
content: Not that simple sorry. The entire system needs to change if you want to make use of the added bandwidth.

author: Shock
author_rank: Super Contributor
timestamp: March 19, 2014, 06:15:55 am
content: Obviously the more data you push the better it is to have a faster interface.However, in many cases it's a cheap device or slow computer not the USB2.Consider USB2 bluray players, they work fine playing HD quality video.USB2 can transfer at 35 MB/s, it depends entirely on the camera and compression on how smooth it looks.Those cheap webcams aren't exceptional quality.You have to spend around $80-$100 minimum on a webcam before you get out of the cheap models.This is why good USB microscopes are expensive.
USB 3.0 hub design questions - Page 1
Forum section: electronics / beginners

author: NORange
author_rank: Contributor
timestamp: September 18, 2025, 12:35:38 am
content: I might have messed up the type-C port wiring, is there a better way to approach this? Also the vias on the USB IC are stripping away too much of ground copper (green) imo, do yall think it's an issue? What about the length matching? I've found several tutorials on KiCAD impedance controlled diff pair layout, but some ppl advise against using the KiCAD trace length matching?

author: NORange
author_rank: Contributor
timestamp: September 19, 2025, 06:59:46 am
content: Compressed project files and gerber files for more context.

author: NORange
author_rank: Contributor
timestamp: September 19, 2025, 07:02:38 am
content: Somehow the gerber file got eaten
USB 3 power and data setup - Page 1
Forum section: electronics / beginners

author: bitman
author_rank: Unknown
timestamp: June 04, 2019, 06:51:17 pm
content: I need some suggestion/advice; I have an old phone using USB 3 (the smooth round plug that goes in either way) cable to charge and plug into a computer. Unfortunately it's one of those model where the battery isn't replacable and well, the battery is about as dead as a door nail (hard power down after just a few minutes of use after full charge). I need to copy the data including the on-device-only encrypted content to a new phone, and to do that I just need to connect the two phones together using the same cable. If it wasn't for the phone dying after a few minutes after plugging it in this way, that would be easy.I can keep the phone running by plugging it into power - but that means I cannot connect it to the new one. So my question is, can I create a Y-Cable where I can provide power _and_ plug in the data side too connecting the two phones? It looks like when there's a data connection, power isn't provided between the two devices - will providing power be a problem? Not sure how to find the answer to questions like this - so I'm seeking expert advice in regards to my options here.Thanks.

author: thm_w
author_rank: Super Contributor
timestamp: June 04, 2019, 08:58:30 pm
content: It doesn't have any method for Wifi backup? I can't see this causing any problems, using 5V power.The Note9 and maybe other phones have the ability to charge other devices over the USBC connector, but sounds like yours doesn't.
USB 5V Generator Question - Page 1
Forum section: electronics / beginners

author: Electro Fan
author_rank: Super Contributor
timestamp: March 13, 2019, 06:05:22 pm
content: What are the chances, if the motor propeller/motor shaft turned fast enough, that this would reliably power an Arduino Uno?Thxhttps://www.amazon.com/Fityle-Turbine-Generator-Alternator-Emergenc/dp/B07CG76JP1/ref=pd_day0_hl_201_4/145-4063635-4588945?_encoding=UTF8&pd_rd_i=B07CG76JP1&pd_rd_r=a7802452-45b9-11e9-9fed-6f308a1afb98&pd_rd_w=aQ8Oy&pd_rd_wg=tKMM5&pf_rd_p=ad07871c-e646-4161-82c7-5ed0d4c85b07&pf_rd_r=NHM97M9ZKM9H8SKS2NGW&psc=1&refRID=NHM97M9ZKM9H8SKS2NGW

author: Electro Fan
author_rank: Super Contributor
timestamp: March 13, 2019, 07:01:40 pm
content: More Questions1. Is it correct that the baseline load presented by an Arduino Uno (with nothing much going on other than lighting the onboard LEDs) is about 100 Ohms?2. What happens if the DC generator's RPMs vary and the resulting voltage from the generator varies, and therefore the Uno sees more or less voltage (for example 6 Volts or 4 Volts), and therefore draws more or less current?3. If the RPM (and therefore the voltage) of the generator is likely to vary, would it be best to power the Arduino via the USB port, or the DC power jack, or the VIN & GND pins. Which would provide the best Over Voltage/Over Current protection, and voltage/current regulation (if any)?

author: jeroen79
author_rank: Frequent Contributor
timestamp: March 17, 2019, 02:37:10 am
content: Quote from: Electro Fan on March 13, 2019, 06:05:22 pmIf the motor spins "fast enough" then it would by definition be able to "reliably power" something, otherwise it wouldn't be spinning "fast enough", now would it?The question is how much power this thing can generate at a given airflow.It claims 0.01-0.3A output current, but under which conditions?You'd have to ask the seller for data or buy it and test it yourself.Quote from: Electro Fan on March 13, 2019, 07:01:40 pmSort of, it idles around 45 mA.QuoteThere is a voltage regulator between the generator and the load.As long as the generator stays within the regulator's specified input range it would provide 5 volts.If the input voltage becomes too low or too high then the regulator may stop proper regulation or shut off.QuoteThe DC in port goes to a regular which turns whatever comes in into 5V.Since you already have a 5V regulator in this kit I would go for the USB input.
USB Backup batteries for Portable power supply - Page 1
Forum section: electronics / beginners

author: SolarSunrise
author_rank: Regular Contributor
timestamp: March 18, 2014, 08:11:08 pm
content: I got tired of trying to find a good bare lithium ion batteries with a connector in ebay. However, searching through amazon I found loads of cheap yet powerful battery banks. Here's one that I've been eyeing for a while:http://www.amazon.com/dp/B00CEZJT2E/It is intended for charging smartphones but the brief specs were perfect for my project, except all the meaty details were hidden from view. Does anyone know the ripple of these USB Backup supplies? If there are a lot of ripples, then what are the solutions? Throw in bunch of Tantalums? Insert a voltage regulator?EDIT:Note: My circuit contains an STM32F4 uC and precision ADC and Analog Front end. I was thinking that the ripple would pollute the sub uV signal. Will tantalums solve the issue? Please let me know!Thanks as always everyone!

author: abbotsmike
author_rank: Contributor
timestamp: March 19, 2014, 01:11:45 am
content: I have an Anker Astro3e, and am back in the lab at uni tomorrow. If I have a chance I'll get a scope on it and let you know!
USB based oscilloscope GND connection problem - Page 1
Forum section: electronics / beginners

author: nhm89
author_rank: Newbie
timestamp: June 15, 2016, 05:40:49 pm
content: Hi, I have the 2204A picoscope, is working very well but I need to view some signals on the raspberry pi, the problem is that when I connect the ground of the picoscope to the raspberry then the USB communication between the oscilloscope and the desktop computer is lost, right after is reconnect but again right after the connection is lost again and I have this ping pong until I disconnect the picoscope GND from the raspberry. What can I do to solve this issue in order to do not burn my piscoscope, raspberry or the USB port.Thanks in advance!

author: suicidaleggroll
author_rank: Super Contributor
timestamp: June 15, 2016, 05:42:17 pm
content: It's probably a ground loop or short caused by different grounds.The best solution would be to isolate the RPi using a floating power supply.

author: nhm89
author_rank: Newbie
timestamp: June 15, 2016, 05:48:40 pm
content: Quote from: suicidaleggroll on June 15, 2016, 05:42:17 pmif i connect a wire between RPI PS and computer it will be ok?I don't know what is a floating PS

author: rstofer
author_rank: Super Contributor
timestamp: June 15, 2016, 09:26:40 pm
content: One version of a floating supply is a battery.What must happen is the USB ground must be at the same level as the oscilloscope ground (it will be) and the RPI ground. If that isn't the case, perhaps another wall wart will have some isolation. Or, get an isolating transformer to float the wall wart. They are commercially available. Make sure your ground lead is actually connected to a RPI ground pin. It's easy to be off by one.I haven't tried my USB Analog Discovery on a RPI but I'm about to. Hm...

author: suicidaleggroll
author_rank: Super Contributor
timestamp: June 15, 2016, 09:34:33 pm
content: Quote from: nhm89 on June 15, 2016, 05:48:40 pmA floating PS means it doesn't have any reference to actual, real ground. V+ is 5V above V-, but both are floating with respect to actual ground.The computer has a real ground, using the 3rd pin in the power plug. The USB shield is tied to this ground, which means the Picoscope is tied to this ground. That means the ground lead on your Picoscope is actual ground, with a solid connection back to the earth, just like a normal oscilloscope. And just like with a normal oscilloscope, this means you need to be careful what you attach it to. If you attach it to something that's floating you're fine, if you attach it to something that also has its own earth connection, at best you'll create a ground loop, and at worst you'll create a short circuit.As for how you get a floating supply for your RPi, there are several ways. As rstofer said, a battery would work, or an isolated wall wart (some are, some aren't) would work. You could also use an isolating transformer to isolate the wall wart, or you could use a bench power supply which will almost always have floating outputs.
USB battery eliminator circuit - Page 1
Forum section: electronics / beginners

author: thundercats_nz
author_rank: Newbie
timestamp: June 07, 2023, 10:35:51 am
content: Hi all,I bought a couple of cheap USB battery eliminator devices that take 5v and step it up or down to match a fixed number of AAA batteries, e.g 3v, 4.5, 6v. see herehttps://www.aliexpress.com/item/1005003330462814.htmlI had hoped that I could take them apart and easily change the output voltage, i.e there would be an smd potentiometer on the board. But no such luck.I have attached a picture of the step up 6v circuit board, could anyone tell me if it woud be possible to add a potentiometer and where?Alternatively, what resistor in the circuit is determining the output voltage?Thanks!

author: m k
author_rank: Super Contributor
timestamp: June 12, 2023, 02:38:30 pm
content: Diode seems to be towards the output.Maybe it's a boost converter.I guess you need to draw its circuit.

author: tunk
author_rank: Super Contributor
timestamp: June 12, 2023, 03:25:20 pm
content: You could try to solder a 1M resistor in parallel with R1 and seeif/how the output changes. It may be that it uses different electronicsfor step down and step up, so you may not be able to change thevoltage below 5V.

author: CountChocula
author_rank: Unknown
timestamp: June 12, 2023, 03:28:20 pm
content: That looks like a boost converter to me as well—probably something like anMT3608or similar. The feedback divider should be given by R1 (91k) and R3 (10k), which suggests a Vref of 0.6V for a 6V output (which also matches the '3608). You should be able to change R1 so that your new voltage satisfies the formula Vout = 0.6V * (1 + R3/R1). Note, however, that you will not be able to decrease the voltage below 5V—that would require a different topology, and the battery eliminators that do likely contain a buck converter with a different chipset.—CC

author: thundercats_nz
author_rank: Newbie
timestamp: June 13, 2023, 12:40:52 pm
content: Thanks for the replies!Will try and add a variable resistor to R1 and see what happens... I'd hope that seeing it was labelled as a "Buck/boost convertor" the circuitry would be be shared for step down/up.If I make any significant progress, I will post an update for the future reference of others.Cheers

author: tunk
author_rank: Super Contributor
timestamp: June 13, 2023, 12:46:39 pm
content: You could try to confirm CountChocula's theory by measuring the voltages across the resistors.

author: thundercats_nz
author_rank: Newbie
timestamp: June 13, 2023, 01:14:25 pm
content: Sorry of course...Voltages as measured are:R1: 5.53vR2: 0.49vR3: 0.61v
USB boost circuit won’t charge apple devices - Page 1
Forum section: electronics / beginners

author: EvolveRedux
author_rank: Newbie
timestamp: September 30, 2019, 12:17:56 pm
content: So I purchased a pre-built USB boost circuit from Jaycar Electronics, and soldered a 3 volt lithium battery onto the terminals. Then when I went to plug in the iPad it didn’t recognise it as a charger, instead as a USB accessory. I waited a couple of hours to see if it did charge, it still didn’t. I tried plugging into something other than the iPad and was successful charging other devices that weren’t apple devices. I’m not exactly sure what is wrong with it, but if you could help it would be great.

author: solderfreelead
author_rank: Newbie
timestamp: September 30, 2019, 12:56:31 pm
content: Have you tried using a genuine Apple USB charging cable (or a compatible one)?

author: mikerj
author_rank: Super Contributor
timestamp: September 30, 2019, 01:34:41 pm
content: You need to tie the D+ and D- data lines to the correct voltages. More details inthis article.

author: mariush
author_rank: Super Contributor
timestamp: September 30, 2019, 01:37:13 pm
content: Or use a proper IC that can set the right signals on the data pins of the USB.See my post here:https://www.eevblog.com/forum/projects/charging-multiple-devices-with-a-simple-5v-power-supply/msg2714808/#msg2714808

author: EvolveRedux
author_rank: Newbie
timestamp: September 30, 2019, 09:58:16 pm
content: Yeah I’ve been using a apple offical cable.
USB-C connector - Page 1
Forum section: electronics / beginners

author: Jane
author_rank: Frequent Contributor
timestamp: March 19, 2019, 12:14:29 pm
content: If I plug in USB-C charger into USB-C connector, on which pins I can measure the voltage coming from the charger?( there are so many pins on USB-C connector )

author: Deepak
author_rank: Regular Contributor
timestamp: March 19, 2019, 12:23:59 pm
content: USB-C is symmetrical, and you want the GND and VBUS terminals.

author: timgiles
author_rank: Regular Contributor
timestamp: March 19, 2019, 12:27:09 pm
content: VBUS and ground

author: Richard Crowley
author_rank: Super Contributor
timestamp: March 19, 2019, 12:39:01 pm
content: Remember that USB-C power is NOT static like older, more primitive power schemes. There are at least three different voltage and current states that are negotiated between the power source and the load. And there is also provision for "proprietary" power modes. So if you simply measure the static voltage, that is only the "default" voltage/current.Ref:https://en.wikipedia.org/wiki/USB-C#USB_Power_Delivery_Specification

author: vignesh_shan
author_rank: Contributor
timestamp: March 25, 2019, 08:21:47 am
content: If i connect the device which requires around 3A current in the USB 3.0 PC. Does all the USB (Type A connector female)3.0 PC provide 3A current?Also pls let me know the link for device hardware configuration to getting 3.0A current in the Type C connector.

author: tooki
author_rank: Super Contributor
timestamp: March 25, 2019, 01:08:11 pm
content: Quote from: vignesh_shan on March 25, 2019, 08:21:47 amNo. The USB 3.0 standard provides for 5V/0.9A, so that's all you can expect to be available.Quote from: vignesh_shan on March 25, 2019, 08:21:47 amTo go beyond 5V/1.5A, you have no choice but to use USB Power Delivery negotiation. (Not including proprietary charger schemes like Apple's 2.7V sense voltage to get 5V/2.4A.)
USB-C PD protocol - Page 1
Forum section: electronics / beginners

author: BeBuLamar
author_rank: Super Contributor
timestamp: January 06, 2025, 04:56:32 pm
content: As I understand it a USB-C PD port would communicate with the device plugged into it so it would know what kind of voltage and current limit it should output to the device. Anyone know how to do the communication to get it to deliver the right voltage that I want?

author: ejeffrey
author_rank: Super Contributor
timestamp: January 06, 2025, 05:29:05 pm
content: The signalling is somewhat complicated. You first have to check for passive resistor pin strapping for 5V current limiting, then check the cable for an electronic ID chip, then communicate with the remote end through a pulse-width signalling protocol, keeping in mind that the other end may want to be a PD source, sink, or either, and you have to consider that CC1 and CC2 can be inverted. You also need to switch the power supply, as USB type C does not allow connecting the 5 V Vbus until the remote side is detected.It's nothing you couldn't do yourself with a micro-controller, but its probably a lot easier to use a stand along PD controller such as the STUSB4700 series, or any number of TI products.