hybridfree/eevblog-posts huggingface dataset:
Keeping LEDs around same power when switching sources - Page 1
Forum section: electronics / beginners

author: rprice5821
author_rank: Newbie
timestamp: November 21, 2024, 11:39:14 pm
content: I'm looking to make a circuit that allows LEDs to be powered via 12v when plugged in, or off a battery when not plugged in. When plugged in the battery would be able to charge. I believe I (roughly) have it working, but I'm struggling with a way to keep the LEDs around the same brightness when being powered by the different sources.

author: oPossum
author_rank: Super Contributor
timestamp: November 22, 2024, 12:53:24 am
content: Simple constant current sourcehttps://tinyurl.com/25woqaya

author: Smokey
author_rank: Super Contributor
timestamp: November 22, 2024, 02:20:09 am
content: Lots of led driver chips are current regulated.

author: Zero999
author_rank: Super Contributor
timestamp: November 22, 2024, 11:50:47 am
content: Use the LM317L. RL in this circuit represents the load, which is the in your case. R1 can be 240R for a current of 5.2mA.

author: Doctorandus_P
author_rank: Super Contributor
timestamp: November 22, 2024, 01:41:31 pm
content: A constant current source such as shown with either a BJT or an LM317 does work, but it still wastes a lot of energy. LED driver IC's these days are usually SMPS based (I.e, they use an inductor) and they have a much higher efficiency. You can get a bunch (100 or so) from aliexpress for a few EUR (such as PT4115). That is a few cents each. The inductor itself will cost more. But total cost is not something to really worry about. Get some and experiment a bit with it.

author: Benta
author_rank: Super Contributor
timestamp: November 22, 2024, 04:46:53 pm
content: I highly doubt that a LM317 CC will work at only 4.8 V input.

author: Zero999
author_rank: Super Contributor
timestamp: November 22, 2024, 06:42:10 pm
content: Quote from: Benta on November 22, 2024, 04:46:53 pmGood point. It depends on the forward voltage and current. It should be fine with 5.2mA and a red LED with a forward voltage of 2V. Even if the current drops a little, it's still better than just a resistor. Failing that, use a proper current regulator IC.Looking at the OP's circuit again, they want a light source, rather than an indicator, so they should go with a buck regulator, as Doctorandus_P said.EDIT:Added simulation. Yes, the current does drop a little, from 5.2mA to 5mA, which wouldn't be very noticable. Oh I forgot to plot VFwhich was about 2.1V and didn't change much,
Keeping reset pin low for a while during startup? - Page 1
Forum section: electronics / beginners

author: fubar.gr
author_rank: Unknown
timestamp: October 07, 2016, 04:59:06 am
content: I implemented the 555 monostable circuit shown here, using a Intersil ICM7555 SMD CMOS chip:It works as intended, save for a small inconvenience. When the circuit is first powered up, the output is turned on for the predetermined time interval, as if the pushbutton was pressed.I believe the problem is that the voltage on Threshold pin takes some time to rise due to the pullup resistor (R2). I fed 12 Volts directly to the Threshlod pin, bypassing the pullup and the problem went away.One possible solution I came up with, is to keep the Reset pin low for a while during startup, by connecting a resistor and capacitor in this fashion:Will this work?

author: danadak
author_rank: Super Contributor
timestamp: October 07, 2016, 09:29:05 am
content: A page of applications, and one that shows another approach.http://home.cogeco.ca/~rpaisley4/LM555.html#10"Power-Up Reset For 555 Timers" section on page.Regards, Dana.

author: rob77
author_rank: Super Contributor
timestamp: October 07, 2016, 10:27:13 am
content: you need to add a way of discharging the reset capacitor, otherwise it won't work in scenarios when you power off and shortly after power on the circuit.if you have a look at the page form the post above posted by Dana - in the first schematic the D1 diode is providing the needed discharging.
Keith monks cr-503 machine how to use? - Page 1
Forum section: electronics / beginners

author: Masterturk
author_rank: Newbie
timestamp: June 18, 2021, 10:27:08 pm
content: I won this machine off ebay, as i wanted to get a good machine to clean records, but im not sure how to use it? I added some alcohol and distilled water to the single pot but nothing seem to be functioning.The chap i bought it off said hes not sure how it works as it was his brothers and he sadly died...When i turn it on the vaccum seems to come on, theres also the nylon thread but it seems to not take it through the tube, also nothing happens when i turn it on it judt rotates, the fluid doesnt come through?Is there something im missing do i need to check for blockages, if someone can help that would be much appreciated as it seems for now i have a expensive paperweight with no idea on how to use it

author: themadhippy
author_rank: Super Contributor
timestamp: June 18, 2021, 11:32:17 pm
content: why not contact the manufacturershttp://www.keithmonks-rcm.co.uk/index.html
Keithley 200b batteries - Page 1
Forum section: electronics / beginners

author: Ignatz
author_rank: Newbie
timestamp: August 02, 2023, 06:33:45 pm
content: Hi, I have two of these Keithley 200b dc vtvm that run on batteries.Inside there are,5 D cells1 C cellthat's easy, Then two 30 volt batteries and six 22.5 volt batteries.With my first Keithley 200b, I combined three new 9 volt batteries together to get approximately 29 volts. and then two 9 volts together to get around 19 volts for the 22.5 volt range. I ran these short wires with alligator clips on them to connect the batteries back up to the unit.Because my goal was to just see if the Keithley worked, it did, but obviously with wires going everywhere, it looked messy.I since got another Keithley and have a question about the six 22.5 volt batteries.The grounds for all the batteries in this Keithley are all separate. None of the 22.5 volt batteries share a common ground.Is it possible to run a single 22.5 volt power supply to all six 22.5 volt battery locations and install some kind of isolation in the ground wire to each battery location as not to join the grounds together.I can easily run out and buy more 9 volt batteries, but was curious if I could do something with an Acopian 24 volt power supply I have laying around. I just like playing around with this older stuff and thought I'd ask.

author: wasedadoc
author_rank: Super Contributor
timestamp: August 02, 2023, 07:39:54 pm
content: Quote from: Ignatz on August 02, 2023, 06:33:45 pmPossoble but not simple. Essentially you would need to employ dc-dc converters with isolation between input and output sides.Are any of the 22.5volt batteries in series, ie +ve of one connected to -ve of another?

author: Ignatz
author_rank: Newbie
timestamp: August 02, 2023, 08:24:04 pm
content: I just checked the two groups of two 22.5 volt batteries that are close together and your right, they are in series. The other 22.5 volt batteries are completely separate from another. I checked them with an ohm meter first and saw continuity between the + and - of the two battery connection points. And I installed double 9 volts in these battery positions, and saw 39 volts between them.I'll just get more 9 volts to "sorta" make my 22.5 volt batteries and be safer. Thanks for your help.
Keithley 2015 + RS232 = frequency response chart ? - Page 1
Forum section: electronics / beginners

author: jimon
author_rank: Regular Contributor
timestamp: February 09, 2015, 08:21:29 pm
content: Hi, I've finally got RS232-USB cable, 1.88$, 2x cheaper then one ride on a bus here in SwedenAnd I also have nice looking Keithley 2015. I've checked connection, it actually works, ":DATA?" do return me current dataAnd I saw a lot of promo materials show nice graphs like this :So, how one can do this graphs actually ? Is there a software to do it ? (I haven't found actual software from Keithley). Or should I just write little app with Qt ?PS. Is there list of all available scpi commands for this device ?

author: 2bluesc
author_rank: Contributor
timestamp: May 13, 2017, 06:12:16 pm
content: Did you ever find an answer? I'm looking at building something similar in Linux (maybe Sigrok does something already?) using python or something.

author: tooki
author_rank: Super Contributor
timestamp: May 14, 2017, 04:38:29 pm
content: I know you can do it with things like Matlab, and almost certainly with LabView.

author: Muxr
author_rank: Super Contributor
timestamp: May 15, 2017, 05:32:27 am
content: As long as you can capture data you should be able to chart it yourself. Python has tons of charting libraries..https://lisacharlotterost.github.io/2016/05/17/one-chart-code/There is an example of a logarithmic chart on that link, like the one you'd use for audio frequencies.
Keithley 2110 Display - LED Replacement / Circuit - Page 1
Forum section: electronics / beginners

author: Barry_2022
author_rank: Newbie
timestamp: May 23, 2024, 11:26:51 am
content: Hi, I have a Keithley 2110 with an LCD display and the backlight LEDs have blown. Not for the first time by the look of it and the small backlight board on one of the backlight panels looks looks unrepairable. The LEDs are 603 size and are wired 2 sets of 3 in parallel. These are connected in series to a 5V supply to the main human interface board (LCD and keyboard switches). As far as I can see there are no ballast resistors and the backlights modules are near zero ohms to the 5v supply.At first I was concerned that the resistor R303 appears to be absent (may have been removed by a previous owner to increase the brightness?) , but as its wired in parallel then its not going to control the current to the back panel anyway.So my question is what voltage colour LEDs should I use to replace the blown ones with. If I use white the typical Vf is 3.4V and the total V for the backlight is 6.8V not the 5V supplied. Is this an issue?Thanks Barry

author: aliarifat794
author_rank: Regular Contributor
timestamp: May 24, 2024, 02:16:15 pm
content: White LEDs typically have a forward voltage (Vf) of around 3.0V to 3.4V. If you use white LEDs with a Vf of 3.4V, the series configuration (2 LEDs in series) will require 6.8V, which is higher than the 5V supply.

author: Barry_2022
author_rank: Newbie
timestamp: May 24, 2024, 02:36:28 pm
content: Hi thanks. The working LED bank (3 x 603 in Parallel) appears to be white and measure 2.5v DC on the diode tester on a Fluke 289 DMM. The LEDs fitted are TY-L0603PW1 with a data sheet Fv of between 2.8 and 3.6V and Ifmax of 30 mA.So I guess the ones I have are on the lower end of thatCheersBarry

author: voltsandjolts
author_rank: Unknown
timestamp: May 24, 2024, 04:08:37 pm
content: I just fitted some random white 0603 LEDsI had lying around and they worked fine.Perhaps the the 5V supply is actually a current source, dunno?Anyway, doesn't seem too critical.

author: Barry_2022
author_rank: Newbie
timestamp: May 29, 2024, 08:48:16 pm
content: Hi thanks every one I ended up using six 603 white LEDs 2 x 3 in parallel and working ok.CheersBarry
Keithley 619  - Page 1
Forum section: electronics / beginners

author: Ignatz
author_rank: Newbie
timestamp: May 09, 2022, 07:40:53 pm
content: I recently bought a Keithley 619 electrometer with the 6194 A and B modules and also got 2 new 6011 triax input cables. I can't get the 619 to respond to any volts or ohms readings, so I checked the power supply.The 5, 15 and -15 supplies look great, but the one part of the transformer is to supply 33 volts AC to the two 6194 electrometer modules because they each have a transformer on them. I'm only getting 19 volts AC coming out of the main transformer, so I think this is where my problem is.I tried switching the two AC inputs back and forth, but no help. Those switches read 0, 100.4 and 119.6 AC volts.Also I have the power supply board out of the unit while taking these measurements.Not sure if repairing this transformer is possible or if I could somehow add another transformer to get my 33 volts AC.Thanks, Rob

author: Kleinstein
author_rank: Super Contributor
timestamp: May 09, 2022, 07:55:54 pm
content: It would be rare that a broken transformer gives out to low a voltage on one winding only. Chances are there is somehow to much a load on the winding in question and thus too much current flowing from the 33 V.

author: Ignatz
author_rank: Newbie
timestamp: May 09, 2022, 09:33:10 pm
content: Thanks, I have the board out of the 619 and not connected to the unit. I also have the two orange wires for the 33 volts AC de-soldered from the board. I'll keep de-soldering transformer wires and see if the 33 volts AC comes back.
Keithley DMM cap's still charged after at least 2 weeks LOL - Page 1
Forum section: electronics / beginners

author: lordvader88
author_rank: Frequent Contributor
timestamp: July 28, 2018, 07:57:40 am
content: I ordered an older style bench DMM almost 2 weeks ago. It arrived today and I unboxed it and flicked all the buttons and some LED lit up for a moment. I wonder how long ago the seller plugged it in? Well at least 1 cap must be pretty good, and not have a bleeder resistor.I never bothered powering it up yet, too late now, bed time.

author: HighVoltage
author_rank: Super Contributor
timestamp: July 28, 2018, 08:13:00 am
content: What model is it ?Some older Keithley instruments have batteries inside

author: lordvader88
author_rank: Frequent Contributor
timestamp: July 28, 2018, 08:22:33 am
content: Keithly 177I forgot tho....there's no probes with it. I'll try some handheld DMM probes with it

author: Muxr
author_rank: Super Contributor
timestamp: July 28, 2018, 05:31:11 pm
content: Maybe it flickered from the inductive power of a switch you were pressing.

author: ArthurDent
author_rank: Super Contributor
timestamp: July 28, 2018, 09:40:59 pm
content: I'd say post #2 from HighVoltage has the correct answer. Check to see if the DMM is fitted with the 1788 battery option. Here is the link to the manual.https://www.utwente.nl/en/tnw/slt/documentation/Equipment/GeneralEquipment/keithley177.pdf
Kemet Data Sheet Log Scale Doesn't Make Sense - Page 1
Forum section: electronics / beginners

author: biker.josh07
author_rank: Contributor
timestamp: June 29, 2017, 03:21:23 am
content: This scale doesn't make sense.I thought that on a log graph each decade was supposed to start at from .0It appears that the decades in this graph (for Kemet common mode chokes) start at .1 which begs the question, where would the .0 be located?Am I missing something? Any help appreciated.Thanks

author: flynwill
author_rank: Regular Contributor
timestamp: June 29, 2017, 03:47:03 am
content: I think you need to go back to your math textbook. Log of 0 is negative infinity.... way, way, way , way off to the left side of that graph.

author: biker.josh07
author_rank: Contributor
timestamp: June 29, 2017, 04:04:36 am
content: Aargh, don't worry folks. It makes sense now
Kenwood CS-5170 measurement - Page 1
Forum section: electronics / beginners

author: Silenus
author_rank: Contributor
timestamp: December 18, 2014, 08:02:30 am
content: Hey guys,Bit of a newbie question here. Was wondering if someone could help me figure out how to read/determine cursor measurements on my Kenwood CS-5170With the delta t option selected it gives me a ratio but I'm not quite sure what it means. How do I find delta t, and by extension other measurements?

author: HalfSpace
author_rank: Regular Contributor
timestamp: December 19, 2014, 09:39:48 pm
content: Hi Silenus,I could not find an operation manual on the web, but I found a service manual. Here is the link if you do not have one.http://elektrotanya.com/kenwood_cs-5170_sm.pdf/download.htmlI think it is reading ratio because the variable timebase control is not in the cal position. The smallest knob on the timebase control needs to be fully clockwise.HalfSpace

author: w2aew
author_rank: Super Contributor
timestamp: December 20, 2014, 02:36:02 am
content: Quote from: Silenus on December 18, 2014, 08:02:30 amIt's giving you a ratio instead of a delta-t because you don't have the variable control on the time/div rotated fully clockwise to the 'calibrated' position. Thus, the horizontal sweep time is not calibrated.

author: Silenus
author_rank: Contributor
timestamp: December 21, 2014, 02:34:27 am
content: Thanks guys, solved the problem
kenwood dcs-8200 dso - Page 1
Forum section: electronics / beginners

author: m3vuv
author_rank: Super Contributor
timestamp: June 08, 2020, 09:02:03 pm
content: Hi all,i have the new to me scope,its my first dso,i wondered if there is any way to display the frequency of a signal,ie a sine wave on the readout using the cursors etc,if so any idea how i do it?,thanks in advance.m3vuv 73
kenwood DCS8200 scope - Page 1
Forum section: electronics / beginners

author: m3vuv
author_rank: Super Contributor
timestamp: November 06, 2021, 07:22:28 am
content: Hi all i have the above 50mhz dso,it says on the front of the unit "programable digital storage oscilloscope,what does it mean by the programable bit?,maybe a silly question but i have always used analog scopes,im pretty much in the dark with this!,tia.

author: m3vuv
author_rank: Super Contributor
timestamp: November 06, 2021, 09:04:05 am
content: is this question beyond you guys?

author: ledtester
author_rank: Super Contributor
timestamp: November 06, 2021, 10:13:17 am
content: QuoteYou expect an answer in an hour and a half???Using a search engine it took me less than two minutes to find the DCS-8200 Instruction Manual.

author: m3vuv
author_rank: Super Contributor
timestamp: November 06, 2021, 07:02:18 pm
content: I have the instruction manual,that wasnt what i was asking,i wanted to know the differences between the kenwood and a regular dso ok.

author: ledtester
author_rank: Super Contributor
timestamp: November 07, 2021, 12:26:25 am
content: Quote from: m3vuv on November 06, 2021, 07:22:28 amIn the instruction manual look at section 5 :
Kenwood TS-140 - Page 1
Forum section: electronics / beginners

author: Eva2256
author_rank: Newbie
timestamp: August 31, 2023, 07:08:02 am
content: gnif: Post was edited to spam, account banned, content removed.

author: Stephen_Pejak
author_rank: Newbie
timestamp: September 13, 2023, 09:28:02 am
content: Well, because you don't have any problems outputing higher power with different input suggests the problem is not in power supply nor is it in the main amplifier. Couple of things could potentially cause this. I will assume that the amplifier uses some kind of MOSFETs but the story is similiar for BJTs(because you didn't mention anything about distortion if you have BJTs, I will assume that you are getting propper biasing in case it's A class). So there are couple of things that the signal passes through, when it is on USB it has to pass through DAC and some filtering so you might consider checking it. After it goes through DAC and filters it goes either to some communication chip that connects it with main preamplifier IC(sometimes integrated in main amplifier IC) or it goes directly to it. All in all those systems aren't easy to deal with, and they sometimes tend to be very complicated. But the fact that you are getting good output with one input and bad output at the other, again, suggests that the problem is somewhere before the amplifier circuit. Also make sure you check outputs of voltage regulators because they can make ICs malfunction if they are oscilating.

author: CaptDon
author_rank: Super Contributor
timestamp: September 13, 2023, 12:57:51 pm
content: 45 watts on AM and FM is the 'carrier' power. I bet your modulation is nearly zero in those modes. SSB output depends on Mic Gain and a control called either 'power' or 'carrier' (my TS-690 has both) The problem is more than likely low mic gain or an incorrect/broken mic.

author: Wallace Gasiewicz
author_rank: Super Contributor
timestamp: September 14, 2023, 09:48:06 pm
content: Captdon has a good pointHere are some suggestions:Check and see if the power out is variable with the slide control, if it is then it is the Carrier only. If this is the case, Problem is in the audio portion of the radioCheck the Mic connection and especially your MicIf you have an audio generator put a one KHz signal into the Mic input pin and key the radio (push SEND button) and see if you get SSB output from the radio. If no output then:Look for the mic amp and see if there is audio signalSee if the audio signal gets to the Balanced MixerIf audio and IF get to Balanced mixer, then look at the mixer.
Kester flux  - Page 1
Forum section: electronics / beginners

author: TorqueRanger
author_rank: Frequent Contributor
timestamp: February 01, 2013, 11:54:54 am
content: I am going to pick up a kester flux pen on ebay but wanted to known if they are god to buy from ebay and can they good bad and is there any questions i should ask before i buy? Also I noticed that a couple people are selling homemade of kester flux in a jar and are these any good and would you trust them?

author: Neganur
author_rank: Unknown
timestamp: February 01, 2013, 06:23:34 pm
content: I'd prefer the Kester 951 (non-rosin) over the Kester 186 (rosin) for hot air SMD type work, since it leaves very little residue behind. The 186 can be quite sticky.Main difference is the percentage content of solids in the flux, the 951 has 2%-3% while the 186 has >30%. The 186 also contains more activator than the 951, which makes the wetting happen a little faster (it removes oxides a little better).They're fairly cheap though, get one of each?

author: marshallh
author_rank: Unknown
timestamp: February 01, 2013, 07:58:02 pm
content: I have several Kester water soluble flux pens, they were legit... DO NOT mess with water soluble fluxes unless you know what you are getting into.I use MG Chemicals rosin flux pen for my SMD/BGA work. Yes, you have to clean up afterwards, no big deal with 99% IPA or flux cleaner, and more importantly no corroded tracks and electrical shorts...Been buying them off Mouser, best stick to reputable distributors unless you want fakes.

author: justanothercanuck
author_rank: Frequent Contributor
timestamp: February 02, 2013, 02:33:18 am
content: I recently bought a Kester 952-D6 flux pen off Mouser. Seems to do the job just fine.

author: nanofrog
author_rank: Super Contributor
timestamp: February 02, 2013, 03:22:02 am
content: +1 for:1. Buy from known vendors such as DigiKey, Mouser, Newark, ... to be sure you've a low chance of getting a fake.2. Avoid water clean flux formulations. Too big a hassle for a hobbyist IMHO (must be cleaned off fairly quickly, and thoroughly, or it will cause corrosion).As per Rosin or No Clean, that's up to you. As mentioned, though Rosin based (R, RMA, RA) may have more solids, it can be cleaned off fairly easily with IPA or good quality flux cleaner. Another member uses xylene (BTW, it mixes with IPA, though I've never tried it).If you're not sure, try both and see what happens (IIRC, you already have a no-clean based roll of Kester solder). ***But if you only intend to get one type right now, you'd do better to match the flux pen formulation with the solder you currently have (prevents chemical incompatibilities).***

author: Fsck
author_rank: Super Contributor
timestamp: February 02, 2013, 04:57:53 am
content: I like 951 personally. I would never trust ebay for highly counterfeited items.
Key car - Page 1
Forum section: electronics / beginners

author: YaFAMAWA
author_rank: Newbie
timestamp: May 08, 2023, 07:34:49 pm
content: Hello,I have a problem with the car keys, indeed I had already replaced the battery some time ago, and there it no longer worked so I reopened itThe PCB was all blue and oxidized and the battery dischargedI don't have a battery so I put 3V on alternate points and the key doesn't work every timeDo you know if I can buy a key PCB on aliexpress and replace the chip?Or will it not work?

author: ataradov
author_rank: Super Contributor
timestamp: May 08, 2023, 07:59:07 pm
content: You need to research for your specific car make and model. In many cases keys are paired to the car in a way that it is impossible to pair a new key yourself. And service centers charge a ton of money for that.Also, the board does not look too bad, if you have any soldering skills, clean the board with alcohol and refresh all the solder joints and it might work without any issues.

author: Kim Christensen
author_rank: Super Contributor
timestamp: May 08, 2023, 08:15:57 pm
content: Well, you can clean the PCB. Then check that the switches are still reliable with an ohmmeter.If that doesn't work, you can sometime buy a new one on-line. Depends on the vehicle. I did this with my 2003 Honda Civic, and all that it entailed to pair the new one to the car, was have the key in the ignition, pressing the brake 3 times (Or some combo of things), and then pushing the button on the new remote. Look up the pairing details online before buying a new one for your car. They are all different. Some are dealer locked and some are not.

author: Faranight
author_rank: Unknown
timestamp: May 09, 2023, 06:52:35 am
content: Just out of curiosity, can you make out the markings on that IC?
Key fill device cryptography - Page 1
Forum section: electronics / beginners

author: rakeshm55
author_rank: Regular Contributor
timestamp: February 13, 2018, 06:55:54 am
content: Hi,What is a Key fill device?? (https://en.wikipedia.org/wiki/Fill_device)Is it just a storage device for keys and pass on the keys to a Security devices??or does it generates keys on its own without manual intervention and stores them so that no human knows what the keys are??Why do we need a device like this?? Is there any standards associated with this ??Please share some insights.

author: BravoV
author_rank: Super Contributor
timestamp: February 13, 2018, 07:12:36 am
content: Quote from: rakeshm55 on February 13, 2018, 06:55:54 amIts called multi factors authentication, google for it, so many at internet.For example 2 factors authentication which are :1. What you know. (eg: the password stored in your brain)2. What you have. (something you must have "except" factor no.1 above)This device is the 2nd factor.Simple example, a safe with 2 factors authentications has tons of money in it, and it is locked, which only you can open it.And unfortunately you are under a gun pointed at your head threatening you to open it, so even you've surrendered your password (the one from you brain), still the bad guy can't force you to open it even you want to, if you don't have the 2nd factor within your reach, say your dog ate it and ran away.

author: Mr. Scram
author_rank: Super Contributor
timestamp: February 13, 2018, 07:42:09 am
content: Rubber-hose cryptanalysis will take care of that. Even if you actually separate yourself from the second factor, parties interested in the contents of your safe will probably make very sure that's a true story before letting you go.

author: drussell
author_rank: Super Contributor
timestamp: February 13, 2018, 11:33:08 am
content: https://xkcd.com/538/
Keysight A1241A multimeter “hunting” - Page 1
Forum section: electronics / beginners

author: stafil
author_rank: Regular Contributor
timestamp: May 27, 2020, 05:14:08 am
content: Does the behavior of this multimeter look ok to you?

author: MosherIV
author_rank: Super Contributor
timestamp: May 27, 2020, 07:29:20 am
content: Mostly yes.Looks like the probes are dirty or have a residue on them stopping good electrical contact.

author: stafil
author_rank: Regular Contributor
timestamp: May 27, 2020, 07:55:07 am
content: This happens with all my probes that work fine on my other meters.

author: MosherIV
author_rank: Super Contributor
timestamp: May 27, 2020, 08:16:34 am
content: HiI have a u1252a.Just tried it with the first pair of leads I could find, pair of uni-t leads.I can replicate what you see if I use the probe lead nearest the sheath, I think the manufacturing release residue is still on the leads there.If I hold the probes together at the indentation near the point tips, it finds the resistance and is stable.Try a bare 4mm banana cable and just join the red and black sockets together.Do you still get the hunting?Try cleaning the sockets with cotton buds and a little ipa.
Keysight ads bjt transistor (Bipolartransistor) Parameter - Page 1
Forum section: electronics / beginners

author: Havass
author_rank: Newbie
timestamp: July 05, 2023, 12:58:41 pm
content: Hello,I am currently working on a small project in which I have to compare transistors with keysight ads. So if I want to test the circuit then I have to name some parameters. But they are not the same as in the Data Shete of Infineon.Would be glad if you could help me.Best regards,Gökhan

author: Terry Bites
author_rank: Super Contributor
timestamp: July 06, 2023, 01:51:47 pm
content: It would help if you said what parameters are missing.Please don't set quizzes.

author: Wolfgang
author_rank: Super Contributor
timestamp: July 06, 2023, 11:56:45 pm
content: This is very normal. Just look at the SPICE models for super plain vanilla transistor like the 2N2222A from different manufacturers.Spice parameters vary quite a lot. If you want an accurate model for *your* specific transistor, you have to do a device parameter extraction.Just look into the datasheets to see that BF and VAF can vary widely, so a "standard" model will have obvious accuracy limits.

author: Havass
author_rank: Newbie
timestamp: July 25, 2023, 10:28:06 pm
content: Thank you
Keysight ADS - Import Component - Page 1
Forum section: electronics / beginners

author: alin_im
author_rank: Regular Contributor
timestamp: June 07, 2017, 08:49:59 pm
content: Hey guys,Can you please tell me how can I add a component into Keysight ADS 2016 ?I want to use the BFR181 in my design, but the RF BJT in ADS has an older version that is manufactured by Siemens.I want to use the newer model fron Infineonhttp://www.infineon.com/cms/en/product/rf-and-wireless-control/rf-transistor/low-noise-si-transistor-up-to-25-ghz/BFR181/productType.html?productType=ff80808112ab681d0112ab6fd2dc27f2#ispnTab7I downloaded the zip, but I don't know what to do with it because i cannot import it like a normal library. Any ideas ?Hope you can help,Alin

author: Keysight DanielBogdanoff
author_rank: Unknown
timestamp: June 08, 2017, 07:54:28 pm
content: I'd recommend giving our application engineers a call, you'll get connected up to an expert in minimal time. If that doesn't work, let me know and I can help get your question sent to the right people.

author: rfeecs
author_rank: Frequent Contributor
timestamp: June 08, 2017, 10:19:50 pm
content: By all means ask Keysight.It looks to me like they just copied the sub circuit files to the folder "Model for ADS2011".So copy that folder to your project lib folder and rename it to bfr181 or something.Then you should be able to open it as a schematic. It is just a SPICE model with some extra inductor and capacitor elements added.I found you have to do File->Design Parameters and change the simulation model from "built-in component" to "subnetwork". Then you can place it in your schematics as a component from your library.

author: alin_im
author_rank: Regular Contributor
timestamp: June 09, 2017, 07:40:11 am
content: Thank you for your reply, it worked.

author: alin_im
author_rank: Regular Contributor
timestamp: June 09, 2017, 07:50:14 am
content: Do you think my final results will be so much different if I am using the Siemens part instead of the Infineon one ? After all, Infineon is just the rebranded version of Siemens so it should be the same.

author: rfeecs
author_rank: Frequent Contributor
timestamp: June 09, 2017, 04:35:06 pm
content: Quote from: alin_im on June 09, 2017, 07:50:14 amI would think they would be the same, unless they are using a different process now.
Keysight application note regarding component testing with scopes - Page 1
Forum section: electronics / beginners

author: Cheagor
author_rank: Newbie
timestamp: January 26, 2019, 11:16:21 am
content: Hello everybody,I have recently acquired a Keysight DSOX1102G. Now I've found this application note by Keysight that gives an example of how to test components with the built-in signal generator.Now I originally wanted to build myself something so I can plot IV curves on my scope, but this seems to be an alternative solution. Would I be missing out on something if I used that the application notes solution instead? Technically, it doesn't measure current but does seem to give general information about the health of a part.I would love to know your opinion about this.Here is the application note I am referring to:http://literature.cdn.keysight.com/litweb/pdf/5990-8366EN.pdfBest,Phil

author: w2aew
author_rank: Super Contributor
timestamp: January 26, 2019, 07:54:59 pm
content: Here's another way to do it using the built-in function generator. Again, isn't perfect since the current sense voltage is added to the DUT voltage, but it works pretty well and is easy to do.and a simple way to measure capacitors and inductors:

author: Cheagor
author_rank: Newbie
timestamp: January 27, 2019, 02:14:48 pm
content: Thanks! I already have found those videos.I would very much like it though, to have the simplest setup that I can get away with, because I am traveling a lot with the scope. If IV gave me something that Trigger/V or V/V, I'd still consider doing it, but if I do, I want to know why I'd need it.Now the way I understand it, is that the use of the external trigger of the signal generator (trigger is built in) makes it possible to observe phase differences. When component testing with an IV Curve, it seems that the predominant factor to determine for example the health of a capacitor would be to look at phase. For that, measuring the I, doesn't seem entirely necessary.
Keysight E3634A: How to turn off the "Beep" sound - Page 1
Forum section: electronics / beginners

author: short_guy
author_rank: Newbie
timestamp: November 23, 2018, 09:08:38 am
content: Hi,I want to proceed ATE test using Keysight E3634A. How to turn off the Beep sound?Have a good day.
Keysight EL34143A CP Range issue - Page 1
Forum section: electronics / beginners

author: pwnell
author_rank: Regular Contributor
timestamp: October 02, 2023, 03:42:55 am
content: I am a bit confused by the following issue I am experiencing when trying to draw a 2.8W load using a Keysight EL34143A DC load.I have set the range to low (8.16W).CP modeI provided power using my DC bench power supply and a fully charged battery as two separate tests to ensure it is nothing funny with the power sourceWhen I try to apply 2.8W CP, the actual power draw drops to 0.8682W. When I draw say 350mW, it works perfectly. 250mW works too. 2W does not.If I switch the unit to Medium range (35.7W), then 2.8W works without issue on the same source. Surely 2.8W << 8.16W, and looking at the specs in CP mode, Low is rated for 0.01W - 8.16W. Why would 2.8W not work in low range mode but it does in medium?See below. Any ideas what I am missing? Perhaps slew rate on the current draw? It is set to maximum.

author: pwnell
author_rank: Regular Contributor
timestamp: October 02, 2023, 02:25:51 pm
content: It appears that CL+ shows up (top right of screen) when I cross 0.8W. Sounds to me like a off by factor of 10 error?

author: pwnell
author_rank: Regular Contributor
timestamp: October 03, 2023, 05:44:09 am
content: I think I figured it out. Might be obvious to some but not to me initially.The device has CP ranges 8.16W, 35.7W and 357W (Low, Medium, High). It also has CC ranges 0.612A, 6.12A and 61.2A. Murphy had me pick a voltage that resulted in current close to the cut off range for CC mode when in CP mode. In other words, in my test 0.8W resulted in 0.617A (presumably just below the current threshold), and 0.9W resulted in 0.62156A (above the threshold). I think in CP mode the range must be set based on the maximum power AND the resultant maximum current drawn for the voltage the DUT is at. It is not enough to look at the power draw alone. The unit will not give you 8W in low range CP mode if your current exceeds the low range value of 0.612A. Therefore 8W will only work on low range mode when V > 13V as I will then be < 0.612 (the upper limit for low range).Unless I missed it, it would have been helpful as a footnote in the manual.

author: pwnell
author_rank: Regular Contributor
timestamp: October 03, 2023, 05:57:53 pm
content: Keysight confirmed:Quote
Keysight MSOX1012A Secure Erase - Page 1
Forum section: electronics / beginners

author: ltktomas
author_rank: Contributor
timestamp: February 14, 2016, 03:47:55 pm
content: Hi, does anyone know, what exactly "Secure erase" does on Keysight 2000 series oscilloscopes ? I've read the manual, but there is not precisely said (at least not for me) what happens if I perform it.I mean do I lose already installed licences or it just cleans volatile and non-volatile memory irretrievably ?* It was supposed to be MSOX2012A in that title

author: ade
author_rank: Unknown
timestamp: February 14, 2016, 07:18:10 pm
content: Typically with "Secure Erase" all non-volatile memory gets wiped, including licenses, configuration information, etc. So be sure to back them up before initiating secure erase.
KICAD 6  PCB dragging a footprint with tracks in place - Page 1
Forum section: electronics / beginners

author: timbopoise
author_rank: Newbie
timestamp: September 21, 2022, 05:16:09 pm
content: Hi,I'm still trying to get the hang of KICAD and would appreciate any suggestions on how to more easily drag a footprint in the PCB editor that has already had some tracks attached.For example, I'm running the DRC check and found that I have a part with overlapping courtyard. I assumed there was a key/mouse operation to be able to drag the part andhave its attached tracks move too.While I'm at it, what's the trick while laying a track to more smoothly go from one lay to next using a via? the 'V' doesn't always seem to work so I'm missing something andthere seems to be more clicks than should be necessary.Thanks in advance.

author: ataradov
author_rank: Super Contributor
timestamp: September 21, 2022, 05:27:47 pm
content: 'D' drags the component with its connections. But if it is a big IC with a lot of pins, it might get tricky.'V' should work to place a via. What specific issues you have with it?
Kicad Error: vector frequency not found! - Page 1
Forum section: electronics / beginners

author: FriedMule
author_rank: Frequent Contributor
timestamp: June 21, 2019, 02:27:22 pm
content: Hi I am trying to simulate a circuit in KiCad but no matter what I select in the list on the picture, I keep getting this error "Error: vector frequency not found!"Can anyone please tell me what's wrong?
KiCad Issues - Routing tracks to footprints - Page 1
Forum section: electronics / beginners

author: Kilroywashere
author_rank: Regular Contributor
timestamp: November 01, 2017, 11:10:53 pm
content: I am trying to make my own PCB for the first time, Just having issues routing tracks to footprints. This is my first time using KiCad so I am really green.Any tips? Or do you know what I'm doing wrong? Any good tutorial vids?Thanks EEVFourm.

author: Mr. Scram
author_rank: Super Contributor
timestamp: November 01, 2017, 11:24:07 pm
content: Quote from: Kilroywashere on November 01, 2017, 11:10:53 pmDid you look for tutorial videos? There are a lot of them out there and not quite hard to find.

author: Kilroywashere
author_rank: Regular Contributor
timestamp: November 01, 2017, 11:27:20 pm
content: I Just thought maybe someone found one that was really good....

author: hermit
author_rank: Frequent Contributor
timestamp: November 01, 2017, 11:37:32 pm
content: Search for contextual electronics getting to blinky.

author: Mr. Scram
author_rank: Super Contributor
timestamp: November 01, 2017, 11:42:34 pm
content: Quote from: hermit on November 01, 2017, 11:37:32 pmThat's the one that will also inevitably pop up when you do look for tutorials.

author: langwadt
author_rank: Super Contributor
timestamp: November 01, 2017, 11:57:16 pm
content: Quote from: Kilroywashere on November 01, 2017, 11:10:53 pmas other have mentioned, "getting to blinky"https://youtu.be/JN_Y93RTdSo?list=PLy2022BX6Eso532xqrUxDT1u2p4VVsg-qIn short what you are doing wrong is that you didn't start with a schematic defining what is connected to what

author: Mr. Scram
author_rank: Super Contributor
timestamp: November 02, 2017, 12:04:52 am
content: Note that KiCad can be peculiar in some areas, so be sure to pay close attention to the more specific instructions or rewatch the video if you don't get it to work the first time.

author: Kilroywashere
author_rank: Regular Contributor
timestamp: November 02, 2017, 02:38:55 am
content: Thanks Forum

author: CCB
author_rank: Unknown
timestamp: November 02, 2017, 05:51:26 am
content: Hi Kilroywashere,Looks like you haven't created a schematic yet? As there is no rats nest in the PCB editor screenshot.From inside EEschema - (these are buttons along the top of EESchema)1. Create Schematic - so it knows how the components are linked togeather2. Annotate schematic - Assign component numbers like R1, R2 etc3. Run CvPCB to associate footprints with schematic components - Choose the physical shape of the components4. Generate Netlist - Exports all of the info in a format for PCBNew5. From PCBNew import/read the netlist - now you should have all the components and a rats nest ready for you to position and draw tracks between them.I think I have all of that correct, yes watch Blinky it will help.Cheers,Carl

author: Kilroywashere
author_rank: Regular Contributor
timestamp: November 02, 2017, 02:40:51 pm
content: Yea, you had that right . I watched a few videos and they helped . Thank you so much !
KiCAD library for screw terminals? - Page 1
Forum section: electronics / beginners

author: MrOmnos
author_rank: Frequent Contributor
timestamp: August 13, 2016, 01:03:54 pm
content: Is there any library for KidCAD out there which contents thishttps://www.sparkfun.com/products/8432screw terminal. Sprakfun library doesn't seem to have it.

author: Monkeh
author_rank: Super Contributor
timestamp: August 13, 2016, 01:13:35 pm
content: It's a 5mm pitch screw terminal.. it takes about 10 seconds to draw one.

author: MrOmnos
author_rank: Frequent Contributor
timestamp: August 13, 2016, 01:49:02 pm
content: Quote from: Monkeh on August 13, 2016, 01:13:35 pmI am new to KiCAD. Since, I am in hurry and don't have time to learn how to do it. I thought someone else might have done this before. Thanks anyway!!

author: Thor-Arne
author_rank: Unknown
timestamp: August 13, 2016, 03:40:48 pm
content: I thought those where included in the stock libraries, but I use my own libraries so I can't check.If not it might be availablehere.But I strongly encourage you to use the time to learn to make footprints, it's an essential part of the process.

author: Lianna
author_rank: Newbie
timestamp: August 13, 2016, 06:42:49 pm
content: Terminal_Blocks:TerminalBlock_Pheonix_MKDS1.5-2pol is a 5mm pitch one, and I believe KiCad installed that library for me through the wizard.
kicad pcb new netlist read error - Page 1
Forum section: electronics / beginners

author: rtaliano
author_rank: Newbie
timestamp: September 03, 2018, 01:48:04 pm
content: I am re-entering the hobby electronics field after quite a few years......meaning I have never used pcb design software. I have been learning KiCad and, while I think I have the fundamentals under control, it appears like many new users that I am in library hell. I chose a very basic project to learn on but unfortunately it is a project for which footprint info was not available through github for most components. I succeeded in importing footprints through Digikey and creating two on my own. I saved them all to a project-specific .pretty folder and added that location to the library list. I thought I had successfully completed the foot print associations with CvPcb....I manually matched up the symbols and footprints and exported/saved the netlist...and verfied that the netlist is in the project folder and opened it with textedit to see if things seemed to be in order. BUT, when I open pcbnew and attempt to read the netlist I get an error messages like the ones below for every component.Error: Component “R2” footprint “PR02000206802JA100” was not found in any libraries in the footprint library table.Error: Cannot add new symbol “R10:/5B8BE1AC” due to missing footprint “Cap_Disch:CF12JT300R”.So I am guessing I somehow have things organized wrong. One thing that confuses me is the footprint libary table. I am not sure what its signficance is if each component has its own footprint (.mod) file. When I view it with text editor it just gives a path ((fp_lib_table(lib (name Cap_Disch)(type KiCad)(uri ${CAPACITORDISCHARGEFINAL}/Cap_Disch.pretty)(options "")(descr "")))This table file appears to point to the .pretty folder as I would expect so I would guess that the location of this table file immediately outside of the .pretty folder doesn't matter?Any help would be appreciated. An hour of googling has not yielded anything useful.Application: kicadVersion: (5.0.0-3-g5ebb6b6), release buildLibraries:wxWidgets 3.0.4libcurl/7.54.0 LibreSSL/2.0.20 zlib/1.2.11 nghttp2/1.24.0Platform: Mac OS X (Darwin 17.7.0 x86_64), 64 bit, Little endian, wxMacBuild Info:wxWidgets: 3.0.4 (UTF-8,STL containers,compatible with 2.Boost: 1.67.0OpenCASCADE Community Edition: 6.9.1Curl: 7.51.0Compiler: Clang 8.0.0 with C++ ABI 1002Build settings:USE_WX_GRAPHICS_CONTEXT=ONUSE_WX_OVERLAY=ONKICAD_SCRIPTING=ONKICAD_SCRIPTING_MODULES=ONKICAD_SCRIPTING_WXPYTHON=ONKICAD_SCRIPTING_ACTION_MENU=OFFBUILD_GITHUB_PLUGIN=ONKICAD_USE_OCE=ONKICAD_USE_OCC=OFFKICAD_SPICE=ON
Eagle test leads - Page 1
Forum section: electronics / beginners

author: Savetheday
author_rank: Regular Contributor
timestamp: November 11, 2015, 10:41:53 am
content: Hi everoneHow do we show in Eagle schematic test leads.Do you know is there any component for that or I better leave it as a wire alone?AndFor sheet layout table how do we add text like Kicad.Do we have to add text manually?Thanks for great helps.

author: electrolust
author_rank: Unknown
timestamp: November 12, 2015, 09:31:46 am
content: For test points, get Bob Starr's library and ULP downloads. One of his libraries is a big set of test points.

author: Karel
author_rank: Super Contributor
timestamp: November 12, 2015, 09:41:28 am
content: Open wires/nets is a very bad idea. Also, the DRU check will raise an error for that.Use one of the testpoints provided in testpin.lbr or create one yourself. Takes only a few minutes with Eagle.
Kicad Via Connections - Page 1
Forum section: electronics / beginners

author: Savetheday
author_rank: Regular Contributor
timestamp: October 03, 2015, 09:22:55 pm
content: Hi everybodyI am working on a project that is made by Kicad.In the Kicad schematics there are via connections i guess otherwise there will be no connections between top layer and bottom layer.How do we figure out which holes are vias and which are for thru-hole components?Thanks

author: codeboy2k
author_rank: Super Contributor
timestamp: October 04, 2015, 03:09:34 am
content: Via's have smaller drill holes than standard through hole components, and when using the PCB program they look different from the larger through hole pads.Also, if you turn on the silk screen and solder mask layers you can see those are nearby to/attached to pads, but not the vias.The default renderer (F9) makes the pads and vias look similar except for the drill size. However, if you use the OpenGL or Cairo renderer (F11 or F12) then the vias look very different from the pads.

author: Savetheday
author_rank: Regular Contributor
timestamp: October 05, 2015, 10:18:33 pm
content: Here are some thru-holes.I copied from pcb schematic pdf file and from kicad pcbnew.
KICAD - Page 1
Forum section: electronics / beginners

author: Munyua44
author_rank: Contributor
timestamp: January 17, 2022, 04:32:09 am
content: Am doing a design on KICAD EDA and after doing the design and trying to have a look at the 3D model, I cant see some footprints being occupied by the equivalent 3D model of the components. How do i add this 3D components models that are missing?

author: rpiloverbd
author_rank: Regular Contributor
timestamp: January 31, 2022, 02:13:50 pm
content: You may also find this helpful: