hybridfree/eevblog-posts huggingface dataset:
Can you identify this part? - Page 1
Forum section: electronics / beginners

author: hermitengineer
author_rank: Regular Contributor
timestamp: June 29, 2022, 08:16:43 am
content: I'm coming up blank on CR1

author: wraper
author_rank: Unknown
timestamp: June 29, 2022, 08:19:02 am
content: Ceramic resonator

author: hermitengineer
author_rank: Regular Contributor
timestamp: June 29, 2022, 08:20:08 am
content: So that must be the oscillator component for the MCU then. Thanks!

author: tepalia02
author_rank: Regular Contributor
timestamp: June 29, 2022, 10:49:46 am
content: Quite close to this one:https://www.ebay.com/itm/233143799848
Can you make pad bigger? - Page 1
Forum section: electronics / beginners

author: crgarcia
author_rank: Regular Contributor
timestamp: May 30, 2022, 07:25:24 pm
content: This is a very stupi@ question. The thing is that since I started "self-learning" electronics, there have been so many times I thought the answer was obvious and I ended up being very wrong - So I decided to ask anywaysThe question is: What are the implications of making a pad larger than the datasheet recommendation?For example, I am trying to solder a SHT40, which is a tiny temperature sensor (datasheet link):this is the recommended pads:I created a PCB (link to full project) with that footprint, but soldering is quite hard, and knowing if it is properly solder is impossible (at least for my beginner skills)Can I make the pads for SHT40 longer and wider?Thanks!

author: james_s
author_rank: Super Contributor
timestamp: May 30, 2022, 07:57:01 pm
content: Sure you can, the only issue you really run into in most cases is creepage but that's not going to matter for a low voltage part like that. Larger pads will consume more solder which is unnecessary with automated assembly but for hand built stuff you can certainly make larger pads to suit your preference.

author: eugene
author_rank: Frequent Contributor
timestamp: May 30, 2022, 08:44:20 pm
content: These sensors are impressive and able to provide humidity measurements that are at least as accurate as many expensive laboratory hygrometers.But in order for it to provide accurate humidity measurements it must be able to make accurate measurement of air temperature. So, for example, be careful not to put it next to a voltage regulator or MCU that generates heat. It's not uncommon to route channels in the PCB around the sensor to limit direct flow of heat from other components. Be sure to provide plenty of ambient air flow around the chip. If you put it inside an enclosure without an adequate window to the room, you might be disappointed with the results.

author: Doctorandus_P
author_rank: Super Contributor
timestamp: May 31, 2022, 09:23:23 pm
content: I do not see much use in making the pads wider, but making them longer is quite common. KiCad even has some "handsoldering" libraries.The recommendations in datasheets are geared towards high volume production, and optimizing yield for such.It also used to be common in industry to have different footprints for "standard" and for "high density" designs. "Standard" had bigger pads and was easier to get reliable in production, while "high density" had smaller pads and was more finicky to setup and needed better machines. I'm not sure but I think this is much less of an issue as it used to be. PCB's themselves have become more accurate, Machines have gotten better, materials such as solder paste has also been improved
Can you Mix two kinds of POTs?  - Page 1
Forum section: electronics / beginners

author: vidarr
author_rank: Frequent Contributor
timestamp: June 04, 2025, 10:27:49 pm
content: In the middle of making this karaoke amp for my daughter (special needs girl), I got this tone controller that is needed for her. I am putting the tone controller knobs on the back of the amp (set and forget and she won't fiddle with it), and a large volume knob on the front for her to control the volume.Is it possible to run wires to a 100k pot and knob on the front of the amp, from the leads of the volume control pot on the tone control board? So, imagine I turn the volume pot on the tone control board to 100%, then the pot tied into it can control the volume from the front of the amp.Basically, I want to bypass the POT on the tone control board and go straight to the POT and knob on the front of the amp, but without having to remove the POT and knob from the tone control board (for the sake of not doing extra work).Thank You!

author: WattsThat
author_rank: Frequent Contributor
timestamp: June 04, 2025, 10:39:23 pm
content: If I understand what you propose, no, it’s not going to work. The unused pot needs to be disconnected and or removed.Bottom line is you cannot put pots in parallel as they act as a voltage divider, it’s not just one resistance, it’s two resistances that sum up to the total with the wiper in the middle.After thought: perhaps it would be easier for you to cut the traces leading to the pot and solder the wires of the front mounted pot to the board upstream of the cuts. Don’t know what your pc board skills are.

author: vidarr
author_rank: Frequent Contributor
timestamp: June 05, 2025, 03:22:54 pm
content: I can do that. I was going to completely remove the pot on the board, but your idea is much simpler. It is too bad I can't just solder the wires of the unattached pot, to the pins of the pot on the board (bottom side).Thanks!

author: Terry Bites
author_rank: Super Contributor
timestamp: June 05, 2025, 05:41:20 pm
content: Cut the tracks to the pot, bodge wires under.In many tone control circuits the pot wiper connects to a point in the circuit which is very succeptable to noise.I'm just sayin'.

author: Refrigerator
author_rank: Super Contributor
timestamp: June 06, 2025, 10:07:58 am
content: Quote from: vidarr on June 04, 2025, 10:27:49 pmThere is a certain threshold of work that you need to do to get your idea working.It involves either cutting tracks, removing the old pot, or splicing wires.If you have a signal coming into the board you can splice into the signal wire and add your external volume potentiometer inline to it. Then you would turn the onboard pot to max and the volume would be adjusted by the remote pot.You can cut tracks and connect your remote pot that way, or you can desolder the existing pot and add your wires there.

author: BradC
author_rank: Super Contributor
timestamp: June 06, 2025, 11:39:40 am
content: Quote from: vidarr on June 05, 2025, 03:22:54 pmJust do that and wire the new pot in its place on leads. No cutting or patching required
can you ran a ac relay coil on dc  - Page 1
Forum section: electronics / beginners

author: amateur_25
author_rank: Regular Contributor
timestamp: November 30, 2019, 05:05:24 pm
content: hiI want to use my finder relay to switch an ac load on based on some logic I have coded on the raspberry pi.Unfortunately I must of not read the spec for the relay properly as the coil requires 24v ac to operate.However I connected it up to my bench supply and it worked fine at around 10vDC.So is there anything wrong with me just using it at 10vdc?Or the coil only takes around 300ma so if someone can think of a simple circuit to invert the dc into ac am happy with that too

author: Kleinstein
author_rank: Super Contributor
timestamp: November 30, 2019, 05:29:57 pm
content: There is a good chance the relay will also work with DC, but at a reduced voltage. However there are 2 possible points that can go wrong:1) There is a small chance that remanent magnetization could be a problem so that the relay could stay on. Normally this should not be a problem.2) With AC excitation the current will be lower in hold state than in the moment of just actively operating. This is because the inductance gets higher when engaged (magnetic circuit closed). This gives good force when needed and low loss when holding. However there is some extra intrinsic loss to avoid rattling. For DC operation this may mean that one may have to use some kind reduced current in hold state to avoid excessive heat during longer operation. It should be OK to use some PWM control to reduce the current in hold state: full power (e.g. 12 V, but could also work with 24 V) for the first 50 ms or so and than PWM (e.g. 50 Hz) at some 20-50% for the hold mode.One could get away with a series resistor that is parallel with a rather large capacitor (could need a few 1000 µF).
Can you replace a unipolar capacitor with a bipolar capacitor? - Page 1
Forum section: electronics / beginners

author: EifX
author_rank: Contributor
timestamp: May 02, 2020, 10:05:58 am
content: Hi There,I am repairing a amplifier but I ordered the wrong caps. I ordered bipolar instead of unipolar.The caps are in the tone control board and are any downsides on using a bipolar cap instead of an unipolar cap?

author: Manul
author_rank: Super Contributor
timestamp: May 02, 2020, 11:43:46 am
content: Normally I think non polarized (bipolar) wlll have a bit higher ESR and will not be the best choice for power supply decoupling. Otherwise it is ok. For your application should be no difference.

author: Gyro
author_rank: Super Contributor
timestamp: May 02, 2020, 12:00:15 pm
content: They might even be better (or at least, more appropriate), depending on whether the circuit actually provided any DC bias across the original polarised ones, or just used them as coupling caps.

author: EifX
author_rank: Contributor
timestamp: May 02, 2020, 02:34:43 pm
content: He Guys,Thanks very much for the replies.I wil go on with these caps.

author: EifX
author_rank: Contributor
timestamp: May 02, 2020, 07:25:06 pm
content: Hi There,Just a little update. The amps work very well with the bipolar caps.Me so happy and thank you all

author: Gyro
author_rank: Super Contributor
timestamp: May 02, 2020, 07:31:09 pm
content: Good result then!
Can you still buy cathode ray tubes? - Page 1
Forum section: electronics / beginners

author: Legion
author_rank: Frequent Contributor
timestamp: February 13, 2014, 01:31:47 am
content: Do they still make CRTs? I've never seen new ones online or in stores, say next to the capacitors. If, for example, you wanted to build your own analog CRT oscilloscope, would you have to use a pull? Or could you actually get a new one? Just curious.

author: wilheldp
author_rank: Regular Contributor
timestamp: February 13, 2014, 01:40:34 am
content: They still make vacuum tubes, so I'm sure there is still somebody out there making CRTs. But I can't help with a potential supplier.

author: c4757p
author_rank: Super Contributor
timestamp: February 13, 2014, 01:42:01 am
content: I've actually seriously considered embarking on a hobby analog oscilloscope project. Probably would use an old Tek tube, there are tons floating around on eBay.

author: dr.diesel
author_rank: Super Contributor
timestamp: February 13, 2014, 01:44:29 am
content: Hameg still makes an analog Scope, probably like nixie tubes though, some huge warehouse in Russia with an endless supply.

author: G7PSK
author_rank: Super Contributor
timestamp: February 13, 2014, 09:11:15 am
content: Still made in India, and Alibaba list them as well.http://dir.indiamart.com/impcat/cathode-ray-tubes.htmlhttp://www.tradeindia.com/manufacturers/cathode-ray-tube.html

author: free_electron
author_rank: Super Contributor
timestamp: February 13, 2014, 04:33:13 pm
content: Please let these things die.....

author: Fraser
author_rank: Super Contributor
timestamp: February 13, 2014, 05:15:53 pm
content: I am pleased to say that CRT's are still very much alive and kickingI bought 10 from China to fit into Digimess oscilloscopes. Cost around $15 each delivered. Russia will also have large stockpiles of such tubes. Take a look on ebay, you should find new and used items.There are also specialist suppliers of new tubes for brand name oscilloscopes such as Tektronix and HP.Long live the cathode ray tube

author: fcb
author_rank: Super Contributor
timestamp: February 13, 2014, 05:31:19 pm
content: I used to have a custom made CRT (mid-late 90's) made, but you'll probably be better off buying far-east or surplus.Take a look at Richardson:www.rell.com

author: T3sl4co1l
author_rank: Super Contributor
timestamp: February 13, 2014, 05:43:55 pm
content: To what end? If you want to make your own scope, might as well find an NOS (= they don't make them anymore, but there's plenty on the shelves) 5AP1 or something like that. Same goes for Tek replacement parts, for example.Or for TV, any junker will do: the yoke coils and flyback are even included for you.If you have a very special CRT that needs repair, you may be SOL, or nearly so: my brother is involved in the Early Television Museum, and vacationed in France last year, visiting one of the last (if not the last, I forget) shops capable of CRT repair.Tim
Can you take a sine wave to rectifier then easily make into AC - Page 1
Forum section: electronics / beginners

author: Beamin
author_rank: Super Contributor
timestamp: September 18, 2018, 12:39:04 am
content: For example put 60Hz AC (+0-through brige rectifier or full wave rectifier so you get a 120 hz signal +0+0+0+

author: IanB
author_rank: Super Contributor
timestamp: September 18, 2018, 12:40:59 am
content: I don't get it. The sine wave you started with is already AC. Are you trying to double the frequency or something?

author: xrunner
author_rank: Super Contributor
timestamp: September 18, 2018, 12:53:27 am
content: Quote from: Beamin on September 18, 2018, 12:39:04 amSure, you will get a 120 Hzsignal, but it won't be asinewave.
Can you use a supercap to keep a microcontroller alive while changing batteries - Page 1
Forum section: electronics / beginners

author: alank2
author_rank: Super Contributor
timestamp: November 20, 2024, 04:37:13 am
content: Let's say I am using a CR2032 to power a microcontroller at 3V. If it is in a very low power mode, can a supercap be used to keep it alive for X seconds while doing a battery change?How would it be connected in circuit? Just like a regular capacitor? Before or after a PTC? If you know the power consumption, is there a formula for calculating how long it will last?

author: brucehoult
author_rank: Super Contributor
timestamp: November 20, 2024, 05:11:56 am
content: Sure, why not?If you take 1 Amp of current out of a 1 Farad capacitor then the voltage changes by 1 Volt/s.So for example if you have an MSP430 drawing 6 µA in standby mode, and a 100 µF capacitor (which costs about 50c) then the voltage will drop by 0.06V/s.
Can you use Pb-Sn solder on PCBs w/Pb-free tinned pads? - Page 1
Forum section: electronics / beginners

author: Syntax_Error
author_rank: Regular Contributor
timestamp: November 20, 2015, 01:32:43 am
content: As the title asks, "Can I use standard lead-tin solder with PCBs that come with pads tinned with lead-free solder?

author: ales22
author_rank: Contributor
timestamp: November 20, 2015, 01:56:29 am
content: Pb solder + Pb-free components, boards etc.: yesPb-free solder + Pb components... :noperhaps yes, if you avoid some types of solder and it's hobby project. (e.g. SAC alloys should be ok, according to Kester's FAQ webpage.)The reason should be, thatcommonsomePb-free solder is very sensitive to lead contamination and it may become brittle and eventually develop some defects. That's what I read somewhere.EDIT: According to blueskull's post, only alloys containing bismuth are sensitive to Pb contamination. Also, as Dave (EEVBlog #180) and others say, don't bother with Pb-free soldering if you don't have to.

author: Ian.M
author_rank: Super Contributor
timestamp: November 20, 2015, 02:04:17 am
content: Apart from the smallest joints, its more a matter of regulatory approval, and for lab work and personal use, that's not really an issue. I certainly wouldn't risk it for applications in high reliability industries, but a carefully hand-soldered Pb-free joint to a factory SnPb tinned component lead that didn't have any gobs of excess solder on it isn't going to be a problem.

author: Syntax_Error
author_rank: Regular Contributor
timestamp: November 20, 2015, 02:59:20 am
content: Thank you both for your responses. My use is hobby/single design. The PCB manufacturer tins the pads w/Pb-free solder as a standard option, and my solder is standard 63/37 solder. I was worried I had a problem on my hands.Thanks again.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: November 20, 2015, 07:53:07 am
content: Quote from: ales22 on November 20, 2015, 01:56:29 amI think it's okay with a tinge of Pb, actually. References say >3% Pb stabilizes solder and platings against tin whiskers. The main disadvantage would be a matte deposit from the wider "mushy" range (= don't nudge it while it's cooling, or you're much more likely to get a cold solder joint!). I haven't heard of mechanical problems with oddball alloys like this -- but you tend to avoid them because they don't make good solder.A good solder solidifies all at once, as much as possible. This is done by choosing a eutectic alloy: the lowest melting point composition, which is just enough of A and B that they effectively dissolve each other / precipitate at the same time. Which leaves very little time for crystallization, so it freezes with a shiny finish, and instantly gains mechanical stability and strength. The choice of eutectic, or nearly pure enough base metals that they still freeze quickly, tends to constrain the number of alloys that are best for soldering. Example: tin-bismuth would seem an ideal replacement for tin-lead, but has much too low a melting point to be practical.Tim
can't find info on these particular TIP508 transistors - Page 1
Forum section: electronics / beginners

author: dentaku
author_rank: Frequent Contributor
timestamp: January 19, 2014, 07:20:52 pm
content: I found these ancient looking TIP508 transistors downstairs in a little bin.They all have three coloured dots on them and a white stripe on the top.I have found datasheets for TIP50x transistors and these look like they're PNP but I haven't been able to find exactly what these particular one's are because I haven't found datasheets for ones that come is this particular package.It's not that I need to use them for anything, I'm just curious.Was it common in the past to put colour bands and markings on transistors?

author: Rerouter
author_rank: Super Contributor
timestamp: January 19, 2014, 08:02:08 pm
content: The markings may be binning, my old tek scope had a similar thing done to all of its transistors,as for infom all i typed was "TIP508 Transistor" and found thishttp://alltransistors.com/transistor.php?transistor=46919

author: dentaku
author_rank: Frequent Contributor
timestamp: January 20, 2014, 03:25:41 am
content: yeah, that page is where I found that it's a PNP but I still don't see a .PDF for the TIP508 with images of the pinout.All the datsheets I find are for TO-220 parts and none are even named 508.The one link on that page that actually says TIP508 links to a .PDF for the TIP47/TIP48/TIP49/TIP50 NPN Silicon Transistor which is obviously the wrong thing.I don't know?Quote from: Rerouter on January 19, 2014, 08:02:08 pm

author: Rerouter
author_rank: Super Contributor
timestamp: January 20, 2014, 06:14:20 am
content: pin out is very easy to determine, take a multimeter and use diode check, that will get you the base pin, then for the collector and emmitor take a generic AAA and a low value resistor, (10K for base aswell),pull the base down with a 10K to the negative, put your first guess for the emitter to the battery positive and your first guess for the collector to battery negative through that low value resistor, if its right you will get a small voltage above battery negative on the resistor if its wrong, no voltage(otherwise if you have a cheapo $10 multimeter they have a transistor tester that you can use to work it out)

author: dentaku
author_rank: Frequent Contributor
timestamp: January 20, 2014, 05:48:17 pm
content: Yes, I tried the transistor tester on my meter and it's still a mysteryIt has 8 holes labeled EBCE under NPN and EBCE under PNP.I've used it before to figure out the pinout of salvaged transistors and it usually works well.If I plug a regular 2N2907 in there the hFE reading is around 200, connected backwards it's 0020 or so, then if I plug it in completely wrong (just to see what would happen) I get 1600 or so which I have never seen before with a transistor.The mystery transistors either gives me nothing or the strange high readings and I think I tried every combination. I even crossed the leads to make sure I tried it every possible way.Oh well, I was just curious. It's not like I have any use for a few old rusty transistors.
LT1495 Comparator Hysteresis Equations - Page 1
Forum section: electronics / beginners

author: mc172
author_rank: Frequent Contributor
timestamp: May 16, 2017, 11:03:17 pm
content: I'm having a play with this:http://cds.linear.com/docs/en/lt-journal/LT1389_0699_Mag.pdfI put the equations into Excel but just cannot get hysteresis to equal 92 mV like they say.I used Vo(max) = Vsupply -0.32 V (and typ. -0.16 V) like theLT1495 datasheetsuggests and I get:Hysteresis = 47.4 mV when Vo(max) is 2.84 VHysteresis = 44.5 mV when Vo(max) is 2.68 VHysteresis = 49.6 mV when Vo(max) is 2.965 V - this makes Vb' - Va = 42 mV which they state, so this is what they must be using for Vo(max).I can't see where I'm going wrong. Can someone please help?

author: mc172
author_rank: Frequent Contributor
timestamp: May 17, 2017, 01:58:14 pm
content: It was a bit late when I posted the above - I should have described what I'm trying to do.I want a low quiescent current circuit to cut off a 12 V lead acid battery at whatever threshold I like. Probably 10.6 V. It's for a piece of remote equipment that I might not be able to get to for a couple of weeks so once the battery is quite well discharged it needs to only present a light load to the battery. The high threshold is not really of much concern other than the need for it to work when I connect the thing in the first place.There are plenty of useful hysteresis calculators and circuit examples on the Internet however I can't seem to figure out how to translate any of them into what I need to do, whereby the supply voltage also varies as the input voltage does. I have tried a particular configuration where the hysteresis resistor needs to be about 1000 times the size of the ones in the potential divider, which is not practical since I want my dividers to be in the order of a few MOhms. The one attached seems to fit the bill but I just can't get it to work on a spreadsheet using the equations they've provided. If I can do this then I can put in my own values to get to where I need to be.Someone must have done something like this before but all I keep finding is Li-Ion stuff which is not of much use without it getting a bit convoluted.
Can't identify an IC SFC2741DC - Page 1
Forum section: electronics / beginners

author: Andrewvee
author_rank: Newbie
timestamp: January 10, 2015, 09:30:10 am
content: Hi all,I hope someone has seen this before!I'm repairing a guitar amp for a friend and I can't identify an IC on the board!The part number (actually all the text) as follows:SFC2741DC7837 (I think this may be a date code)I think its an op amp. I'm trying to find a modern equivalent.I think a LM741CN would work, but I would like a few more opinions from your respective selves!Also, its a Carlsbro Hornet amp circa 1970's vintage.Thank you!

author: sdg
author_rank: Regular Contributor
timestamp: January 10, 2015, 11:57:00 am
content: Quote from: Andrewvee on January 10, 2015, 09:30:10 amYou're kidding or you've never heard of Google ?

author: Andrewvee
author_rank: Newbie
timestamp: January 10, 2015, 12:56:49 pm
content: Do you think I haven't tried? Its an old obsolete IC. Can you find the data sheet?

author: rdl
author_rank: Super Contributor
timestamp: January 10, 2015, 02:04:15 pm
content: Google seems to indicate it's an op amp made by American MicroSemiconductor. It's probably just a 741 clone or knock-off.

author: sdg
author_rank: Regular Contributor
timestamp: January 10, 2015, 02:06:17 pm
content: Google "SFC2741DC", first hit:www.datasheetarchive.com/SFC2741DC-datasheet.html...The first pdf says all that's needed. And if that's not enough for you, the 3rd pdf on the page lists possible replacements.

author: Andrewvee
author_rank: Newbie
timestamp: January 10, 2015, 10:37:47 pm
content: Thank you all. Much appreciated. I'm a novice and wasn't sure if that 3rd datasheet was as you said it was.Thanks again
Can't seem to correctly identify component - Page 1
Forum section: electronics / beginners

author: samw
author_rank: Newbie
timestamp: June 14, 2016, 08:31:48 am
content: Hi I'm completely new to the forum, but I was trying to repair my monitor that went bad and I believe I found out the issue (I replaced the tcon board and tried a lot of other things and that didn't work). I'm a complete noob but I was poking around on the board to look for correct voltages. I came across this voltage regular of some sort I think and I can't seem to find the datasheet for it or a replacement or anything. Am I looking up the numbers wrong? I included a picture of the component and the letters read "028N" or "Q28N" then below "A1528". I was just wondering if someone can help me identify the component and if I can find a replacement.The voltages on the pin read1- 5.05 8- 5.052- 0.81 7- 1.3 (then 3.6V on a different one)3- 0.0 6- 0.04- 0.81 5- 1.34The reason I believe the component is broken is because there is another component exactly like it with the same voltages except for pin 7 where the broken one has 1.3V compared to 3.6V on the other one. The reason I'm trying to fix this is because there are no replacement main boards for my monitor otherwise I would just buy it. It's an HP Envy 32" btw. Thanks in advance.And if anyone was wondering what was wrong with the monitor, it turns on and has sound and back-light, but there is no picture, and unfortunately replacing the tcon board didn't work.

author: wraper
author_rank: Unknown
timestamp: June 14, 2016, 08:43:50 am
content: Measure what's on the other side of the coil connected to pin 7. It's DC/DC converter, on pin 7 there is no DC but high frequency pulses, so your meter will not measure it properly. Also, although other circuit seem to be the same, most likely feedback resistors have different values. Therefore output voltage regulated will be different too.http://www.gmt.com.tw/product/datasheet/EDS-AT1528_1529.pdf

author: ebclr
author_rank: Super Contributor
timestamp: June 14, 2016, 08:47:11 am
content: Try to put a lateral light, try to see on several angles, the marking is sometimes more ease to view on different angle and light conditions

author: wraper
author_rank: Unknown
timestamp: June 14, 2016, 08:53:49 am
content: Also, as there is 0.8V (feedback voltage) on pin 4, that means IC is 100% functional because that means output voltage is regulated to what is set by resistors.
Canbus help - Page 1
Forum section: electronics / beginners

author: MadisonMotors
author_rank: Newbie
timestamp: June 27, 2023, 12:45:49 am
content: I need help transmitting data over a Canbus network. I'm using a control board and software from evbmw.com and openinverter.org to control an electric motor and I need to send RPM, Pedal position, motor temperature, and torque to a transmission controller from htg-tuning.com. The control board has a web interface that allows me to set can id, position, bits, and gain of certain spot values and transmit in little-endian. The GCU has a sniffer and I've confirmed that I can send data but I can't get it into a format that is usable by the GCU.https://wiki.htg-tuning.com/#t=HTG_GCU_User_Guide%2FCAN_BUS_guide.htmlhttps://openinverter.org/wiki/CAN_communicationhttps://openinverter.org/wiki/Web_Interface

author: liaifat85
author_rank: Regular Contributor
timestamp: June 28, 2023, 11:18:53 am
content: Does the GCU have any user manual or datasheet? I think you need to check that to receive your data in a compatible format.

author: DarkMode
author_rank: Contributor
timestamp: June 29, 2023, 08:14:34 am
content: Interesting project. I see they have a Forum on the Open Inverter website, has that proven fruitful?https://openinverter.org/forum/Can-bus isn't really a beginner system in my opinion, buy hey there are Genius about.
CANbus noob question - Page 1
Forum section: electronics / beginners

author: PanSam1986
author_rank: Contributor
timestamp: August 25, 2022, 07:23:07 pm
content: Hi all,I ama total noob when it comes to CANbus, so please be kindI have purchased a bicycle lamp from Supernova that was designed to work with ebikes. I already made the mistake of connecting it to my bicycle voiding the warranty (because I didn’t read the fine print), costing me over 800 euros when the motor was bricked after a corrupt/incomplete over the air update. Selling this lamp is just not going to happen so I thought I would make something that will allow the lamp to work independently from the bicycle. For those interested the lamp in question is an M99 Pro. According to the manual it requires the CAN-H and CAN-L signals to operate. I assume that they are only used as such that once the bicycle is turned on the lamp senses the change in potential and turns the output on. Would this be a safe assumption, or am I completely on the wrong track?

author: ataradov
author_rank: Super Contributor
timestamp: August 25, 2022, 08:45:15 pm
content: From the documentation it is not clear if it needs just any traffic on the bus, or it needs specific frames.But in any case, it would not be as simple as connecting fixed levels. You would need an MCU with a CAN controller and a CAN transceiver to connect it to the bus. You would also need to get information from the vendor on what frames it expects to see.

author: PanSam1986
author_rank: Contributor
timestamp: August 26, 2022, 02:58:38 am
content: @ataradov Thanks for the info. I was hoping for a simple solution but oh well. I doubt the vendor would divulge such information but I can try to get some more details.Is there a reason why they would make it more complex than using the fixed levels as a trigger? It’s not like it needs to communicate with anything on the CANbus.

author: ataradov
author_rank: Super Contributor
timestamp: August 26, 2022, 03:16:38 am
content: I don't see why they would not tell. It should lot be a secret.It depends on what they do with the data. If it is just to keep the light on, then simple levels would be sufficient. But it looks like it has far/near setting, which I presume is controlled by some switch that generates CAN messages.Although it looks like the beam setting switch has a separate connection. So, it might just use CAN level transitions to detect activity on the bus. Again, I think they should be able to confirm that.

author: PanSam1986
author_rank: Contributor
timestamp: August 26, 2022, 10:31:48 am
content: Yes, the hi/lo levels are controlled by a momentary switch connected to the lamp with a separate cable. The lamp also has daylight-running LEDs that are separate from the main LEDs, but those are controlled by a sensor found in the lamp housing.I appreciate your input. Thanks.
CANBus problems - Page 1
Forum section: electronics / beginners

author: viperidae
author_rank: Frequent Contributor
timestamp: September 28, 2020, 09:12:40 am
content: What am I doing wrong?I've tried to read the KCAN bus on my car, which is supposedly 100Khz CAN 2.0.https://www.e90post.com/forums/showthread.php?t=177272I've tried with both an MCP2551 + STM32F303RE and MCP2551 + MCP2515 + Arduino.The best I can get in receive two corrupt looking frames, one in each buffer of the 2551.It's definitely 100kHz, but the voltages seem a bit weird.It's going positive and negative.I thought it was supposed to go between 0V and ~5V.This point doesn't have a termination resistor, but there are several nodes on the bus and obviously they can all talk to each other fine, orCH1 is connected between CANH and CANL, there is no common ground between the car and scope.I've verified the crystal speed in the MCP2551 by enabling the clkout pin and measuring it at 8MHz.I've got the following config registers set:CANCTRL=0b1000000 - listen mode, clkout disabledCNF1=0b00000100 - SJW=0, BRP=4CNF2=0b10010000 - BLTMODE=1, PHSEG=2, PRSEG=0CNF3=0b10000010 - SOF=1, PHSEG=2That should add up to:SyncSeg=1TQPropSeg=1TQPS1=3TQPS2=3TQTotal bit time of 8TQ8MHz clock with a BRP of 4 gives a TQ of ((2*(BRP+1))/8000000 = 1.25uS8TQ * 1.25uS = 100KHzI know the registers are all set as expected, since I can read them back out.I wasted Saturday trying to get this going on the STM32 and wasted Sunday with the Arduino.I don't have any other types of CAN transceivers to try. I was using a DIP8One of the modules uses a TJA1054TThese are my dodgy MCP devices I've been using(looks like the "Insert attachment in the message" feature doesn't work too well...)Edit: I'm an idiot. I was adamant I had CANH and CANL around the right way, but after staring at the scope image and checking which wire I probed as ground, the "fall time" was too sharp for a return-to-zero receiisive bit and the "rise time" was too sloppy for a dominant bit.Swapped the wires and now my interrupt led is flashing like crazy.

author: Doctorandus_P
author_rank: Super Contributor
timestamp: September 29, 2020, 04:42:11 pm
content: When the CAN bus is not driven, both wires are floating, (and pulled to each other with the termination resistors)You can add a few bias resistors (10k to 1Meg or so) to the wires to give them a bias voltage of half Vcc. This may make fault finding with a scope a bit easier.It also makes the signals a bit more symmetrical, which may be (a bit) better for EMC reasons, but probably not terribly important.
LinBus relay board to integrate/emulate with existing controller - Page 1
Forum section: electronics / beginners

author: tomayr
author_rank: Newbie
timestamp: July 02, 2021, 12:15:38 pm
content: Hi all,I am trying to figure out how far out of the realm of possibilities this may be and what sort of costs would be associated.I have a large amount of HVAC touch screen controllers that I would like to re-purpose with a aftermarket relay board. It appears the unit communicates with the control board on the boiler via UART / LIN-BUS. The communication should be relatively basic.I would essentially like to develop a controller that will tie into the hvac controller and turn on relays or gates based on whatever function is selected.Where would I start with no programming experience? Who could I hire? The future $$ potential is not high, so it would have to be a relatively low cost for the development + under ~$100 per controller for it to feasible unless there is a aftermarket on the shelf product that already does this and just needs programming.Any help or input would be appreciated. Thanks for your help.

author: Doctorandus_P
author_rank: Super Contributor
timestamp: July 04, 2021, 08:49:48 pm
content: A simple search in platformio shows a bunch (5+) libraries for the LIN bus.Developing a simple application around it should be relatively easy and straightforward, but verifying interopability with existing LIN systems may be much more challenging.Trying to hire a developer to do the project for you may also be challenging.You can hire developers relatively cheap from countries such as India, but how do you verify the quality of their work without having a reasonable amount of programming experience yourself?The hardware is probably almost trivially simple. A power supply, small microcontroller and some relays together with some small stuff (capacitors, resistors, transistors and such)Re-purposing your HVAC touch screens may be more challenging.It's not just about the protocol they speak, but also about what they are supposed to do with received commands.The data over the LIN bus is probably short. Those controllers probably have menu's, pictures, fonts and more stored locally, and just receive commands to display certain data or request a measured temperature.For an example of generic HMI interfaces, have a look at the "Nextion" displays. These are also controlled via a simple serial interface, but they come with PC software to upload bitmaps, menu's and other stuff which can then be stored on a uSD card on-board the controller.
Cancelling ripple in your PWM DAC - Page 1
Forum section: electronics / beginners

author: Dabbot
author_rank: Regular Contributor
timestamp: August 25, 2019, 04:28:06 am
content: I just triedhttps://www.edn.com/design/analog/4459116/Cancel-PWM-DAC-ripple-with-analog-subtractionand I have to say it works remarkably well.The example on the site includes an external inverter, but I programmed a PIC to generate a complementary 31KHz PWM signal, then sent each output into the RC filter network as seen on the site. 10Kohm resistors and 0.1uf capacitors. Pretty good result for one extra micro pin and two extra passive components.It buries the ripple into the noise as far as I can tell using my scope (noisy environment). The only downside that I can see is the increased time for the output to settle, which can be addressed in software, but isn't a problem for my intents and purposes.Has anyone else taken this approach?
Cannot add a library part to schematic - Page 1
Forum section: electronics / beginners

author: Pedro147
author_rank: Regular Contributor
timestamp: November 29, 2016, 06:48:28 pm
content: I am modifying an existing schematic in Eagle 7.7.0 The library, "regulators" that I wish to use is in my library folder in Eagle so I went to the schematic and selected "Library > Use > regulators" from the menu.When I go to the Add button that library is not available for me to use though. What am I missing here please.

author: Heszu
author_rank: Contributor
timestamp: January 08, 2017, 07:01:13 pm
content: Double click "regulators" ... What happens then ?From toolbar Library select use,,, then select 'regulators'... After that they are accessible/selectable from Add button...Or from left panel Add button, from there choose 'Use' -- scroll find 'regulators' open...Now they appears to be used in schematic..WBRH

author: Heszu
author_rank: Contributor
timestamp: January 08, 2017, 07:22:18 pm
content: regulators.lbr seems to be from 2016, whilst the others are from 2011...Who has added that library, and with what permissionsDo You have the rights ?

author: Pedro147
author_rank: Regular Contributor
timestamp: January 08, 2017, 09:09:59 pm
content: Thanks for your reply Heszu.Yes I followed all the steps that are required to use a Library and there are no special rights/permissions required from what I can see. I ended up finding a Library for this component elsewhere so it is all good. Thanks again for your suggestions though
cannot find this datasheets - Page 1
Forum section: electronics / beginners

author: sarius
author_rank: Newbie
timestamp: April 16, 2018, 06:36:33 pm
content: hello everybodyI openen up my old cd player (SilverCrest Portable MP3/CD player model number KH2278) and found some IC's there.2 of them are the A2364L and the gdt1668co and the problem is I cannot find the datasheets.Because of a school project I need to explain the components of this cd player (how they work and what they do...) and that's why I need those datasheet because I really don't have a clue what they do.Thanks in advance.

author: rfengg
author_rank: Regular Contributor
timestamp: April 16, 2018, 11:16:03 pm
content: Strange that you cudnt find it the first one......comes up as the first on a google search query......gdt1668co ----->>>>https://www.scribd.com/document/15424367/gdt-1668Is the A2364L an opamp? What sort of package is it? The best I cud find is u.r.l'ed below.....A2364L -------->>>>http://pdf1.alldatasheet.com/datasheet-pdf/view/155844/TI/OPA2364AID.html

author: sarius
author_rank: Newbie
timestamp: April 17, 2018, 12:13:01 pm
content: A bit stupid of me that I didn't find the first one. I only searched the internet with the 'co' after it and that does not give a result.I think it is a flat package but I'm not sure.There's a picture of the chip in attachments, also I do not recognise the logo but you can see it in the picture.Thanks already for the first link it helps me a lot.
Cannot load DSLogic (dreamsourcelab-dslogic) driver in PulseView - Page 1
Forum section: electronics / beginners

author: Arvid
author_rank: Newbie
timestamp: May 09, 2024, 02:57:46 pm
content: Hello,I have problems with PulseView an DSLogic on Linux!I checked the driver with:sigrok-cli --driver dreamsourcelab-dslogic --scan:The following devices were found:dreamsourcelab-dslogic:conn=1.8 - DreamSourceLab DSLogic Pro with 16 channels: 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15But when I choose the driver in the 'Connect to device' window, it found no device if I scan it!The LED of the DSLogic is orange!I get the following errors in the log:srd: Failed to load decoder gpib: missing or malformed 'tags' attributesrd: Failed to load decoder iec: missing or malformed 'tags' attributedreamsourcelab-dslogic: Failed to open potential device with VID:PID 2a0e:0003: LIBUSB_ERROR_ACCESS.The lsusb command gets:Bus 001 Device 008: ID 2a0e:0003 Shenzhen DreamSource Technology Co., Ltd. USB-based InstrumentWith Windows (10) it worked!I think it's not really a PulseView issue, but I'm hoping someone can help me.

author: madires
author_rank: Super Contributor
timestamp: May 09, 2024, 03:26:56 pm
content: Quote from: Arvid on May 09, 2024, 02:57:46 pmLooks like a quite old version (gpib and iec are replaced by ieee488). I think you can ignore that.Quote from: Arvid on May 09, 2024, 02:57:46 pmThat should be the cause, i.e. access rights. Most likely the user running PulseView has no access to the device. The best approach is to add a udev rule for the DSLogic Pro to set a specfic group (/etc/udev/rules.d/99-local.rules), and also add the user to that group (/etc/group).

author: tatel
author_rank: Frequent Contributor
timestamp: May 09, 2024, 05:13:57 pm
content: Use DSView, not PulseView. There's bad blood between the guys at Sigrok and DSLabs. So the support in PulseView for DSLab products isn't the best.Download DSView:https://www.dreamsourcelab.com/download/Video from PulseView developer about the drama, go to 27:06
Cannot program M27C001 - Page 1
Forum section: electronics / beginners

author: iskinner258
author_rank: Newbie
timestamp: March 04, 2015, 11:31:27 am
content: I have seen this question on several sites but unfortunately no answers so hoping you guys can help. I have a TL866CS MiniPro universal programmer. I wish to re-program a M27C001 chip. I can successfully read the chip but the buttons to erase the chip are greyed out. Has anyone come across this problem?

author: cyr
author_rank: Frequent Contributor
timestamp: March 04, 2015, 12:01:27 pm
content: I don't know the specific part, but it doesn't sound like a electrically erasable part. If it has a clear window you can UV erase it, otherwise it may be a one-time PROM.

author: iskinner258
author_rank: Newbie
timestamp: March 04, 2015, 12:12:12 pm
content: Thanks CYR. I think you are right. I know it is re-programmable as we normally return them to the manufacturer to do this. It does have the window so suspect it needs to be UV erased.

author: wraper
author_rank: Unknown
timestamp: March 04, 2015, 12:21:57 pm
content: Yes it is UV erasable. If such part is just in plastic case, not ceramic with window, then it is one time programmable.
Cannot solder this connector - Page 1
Forum section: electronics / beginners

author: brainwash
author_rank: Frequent Contributor
timestamp: March 17, 2013, 04:44:50 pm
content: I'm having trouble soldering reliably a power connector. The center pin should go all the way through the board but I just cannot get it to seat and have no idea how to push it down the 4mm or so it needs.It is centered on its hole, it goes one mm or so but not any further. I've tried using a plug to push on it, various screwdrivers in various positions and so on. I'm sure there must be something that should work.No, pushing on the plastic housing does not help, the center pin has a bit of wiggle (for mechanical relief?) so it's almost disconnected from the outer shell.

author: Monkeh
author_rank: Super Contributor
timestamp: March 18, 2013, 12:07:15 am
content: Is the hole clear?

author: scarrier
author_rank: Contributor
timestamp: March 18, 2013, 12:11:41 am
content: have you removed all solder an apply some new solder with a good quantity of flux?(make sure the component is hot and the pad also)

author: IanB
author_rank: Super Contributor
timestamp: March 18, 2013, 12:14:27 am
content: Quote from: brainwash on March 17, 2013, 04:44:50 pmIt seems as though you are not so much having trouble soldering the connector, you are having trouble seating the connector? You cannot get it into place and flush with the board before you try to solder it?Apparently there is some obstruction. Perhaps you need to enlarge the hole where the pin goes?

author: Smokey
author_rank: Super Contributor
timestamp: March 18, 2013, 12:34:55 am
content: If you scavenged the connector from something else, it may still have too much solder on the pin. That would make the end of the pin start to go in the hole, but stop if there was a blob half way up. Make sure both the hole and the pin are clean of solder using some wick before installing it.

author: brainwash
author_rank: Frequent Contributor
timestamp: March 18, 2013, 02:42:52 am
content: Sorry, I cannot take clearer pictures, but it's not a seating problem. Hole is clear, connector was there before but was making intermittent contact.I think by design this pin is pretty short, I expected it to go in until the ridge visible in the picture, but the plastic molding does not let it to. I tried to solder a jumper wire from it to the fuse but somehow the solder does not grab.Could be that it was aluminium or another non-solderable alloy (stainless steel) coated with something and in time the coating wore off.Oh well, I probably have to find a better plug somewhere, otherwise the solder gives up immediately after a little mechanical stress. Yes it's cleaned and fluxed and cleaned again and iron on higher temperature and all possible stuff. It's not oxide.
canon mp610 k30290 circuit board sense pin - Page 1
Forum section: electronics / beginners

author: Rainar
author_rank: Newbie
timestamp: January 17, 2015, 11:29:52 am
content: any visual suggestions how to do that is described below,where is 3,3v in circuit board and where is ground?:The connector has 5 pins, the 2 black are GND, 2 of the others are 24V and 32V and the one on the end toward the edge of the board is Sense. It is NOT the same as an ip4200. AND you will see 7.5V and 10V until the sense line is active, the sense sits near GND if the AC adaptor is taken out of the printer. The sense line goes through a 1k resistor and to the base of an NPN transistor on the power board. I couldn't find a Serv. Manual online so I just figured it out myself. Anyway, I put 3.3V on the sense pin (almost anything will work because of the 1k resistor) and GND on one of the GND pins. That made the other two pins go from 7.5V/10V to 24V/32V. So apparently there is a low power mode and normal power mode.