hybridfree/eevblog-posts huggingface dataset:
#SOLVED # What component is this. A Cap? and Inductor? Logic does not help... - Page 1
Forum section: electronics / beginners

author: Houseman
author_rank: Regular Contributor
timestamp: February 26, 2023, 07:14:37 pm
content: Hi forum.Could You please tell me what kind of component is this?A color coded capacitor? an inductor?If I assume it is a capacitor it has color code 22pF +10% but the schematic does not help. It is placed at the positive input of an external DC 10V supply, so it should have no sense.... the 0V DC and the +10V DC are connected in the differential input of an opamp, and with the capacitor in series current can't flow...If it is an inductor of 47uH it is in another place it shorts Vcc to ground...so I assume it could be a capacitor..but as above it has no sense.. Please help.Any help really appreciated. Thank You very much.

author: Vovk_Z
author_rank: Super Contributor
timestamp: February 26, 2023, 07:16:11 pm
content: Is there a photo?

author: Houseman
author_rank: Regular Contributor
timestamp: February 26, 2023, 07:22:43 pm
content: sorry. upload did not work

author: TimFox
author_rank: Super Contributor
timestamp: February 26, 2023, 08:15:12 pm
content: The only thing that makes obvious sense to connect between Vcc and Gnd is a capacitor.Are you sure your color-code reading is correct (possibly overheated color bars)?That package is strange: looks like an old-school NP0 leaded part that makes little sense across Vcc.

author: mcinque
author_rank: Unknown
timestamp: February 26, 2023, 08:47:30 pm
content: Quote from: TimFox on February 26, 2023, 08:15:12 pmwhat about a bleeding resistor?

author: Houseman
author_rank: Regular Contributor
timestamp: February 26, 2023, 08:49:24 pm
content: Thanks for the reply. The fact is that even an LCR tester does not recognize anything, except once it said a resistor with 89 ohm...By the way. could a so small capacitor be destroyed by heating it up during normal desoldering process? the fact is that it is shorted for the tester... like a resistor as I said before..Thank You

author: Houseman
author_rank: Regular Contributor
timestamp: February 26, 2023, 08:52:58 pm
content: Thanks for your post.Shouldn't be a bleeding resistor be a high value one?and if yes, why not use same 1206 package as the one used nearby the opamp?

author: Houseman
author_rank: Regular Contributor
timestamp: February 26, 2023, 09:01:56 pm
content: FOUND: (thanks to Klaus)It is a Thin Film Micro-MELF Resistor.https://www.vishay.com/docs/20003/smm0102.pdfNow I would like to guess why use it to short Vcc to ground....

author: Kim Christensen
author_rank: Super Contributor
timestamp: February 26, 2023, 09:39:51 pm
content: Quote from: Houseman on February 26, 2023, 09:01:56 pmAre you sure thats what is shorting Vcc to ground? Maybe something else is shorted (Between the MELF and Vcc or between Vcc and gnd) and making it look like that when using an ohmmeter.ie: How have you determined that one end of the MELF is supposed to be connected directly to Vcc?
What component is this please? - Page 1
Forum section: electronics / beginners

author: m.abdelwanis
author_rank: Contributor
timestamp: April 24, 2024, 05:22:44 am
content: Hi, I have an old device in bad condition and I want to know what component this is. If it's an inductor, can you help me identify its type,value or link for an equivalent to order?Thanks All

author: aliarifat794
author_rank: Regular Contributor
timestamp: April 24, 2024, 11:10:37 am
content: According to your test result it is a 1.6V, 3.2 milli henry inductor. But I could not find any having the same outlook. I searched here:https://www.digikey.com/en/products/filter/fixed-inductors/71

author: wasedadoc
author_rank: Super Contributor
timestamp: April 24, 2024, 11:13:36 am
content: Quote from: aliarifat794 on April 24, 2024, 11:10:37 amNo, not microHenry. Measuring device is showing mH. milliHenry.

author: shapirus
author_rank: Super Contributor
timestamp: April 24, 2024, 11:45:56 am
content: That marking is interesting. "239"? What is it supposed to mean?

author: Zero999
author_rank: Super Contributor
timestamp: April 24, 2024, 12:04:37 pm
content: As it's a good part, why do you want to order a new one?

author: m.abdelwanis
author_rank: Contributor
timestamp: April 24, 2024, 02:49:07 pm
content: Quote from: Zero999 on April 24, 2024, 12:04:37 pmCircuit board has three inductors. One is faulty and needs to be replaced.

author: m.abdelwanis
author_rank: Contributor
timestamp: April 24, 2024, 03:40:51 pm
content: Quote from: shapirus on April 24, 2024, 11:45:56 amI'm feeling confused because there is no brand and I don't understand what the markings mean.

author: m.abdelwanis
author_rank: Contributor
timestamp: April 24, 2024, 03:43:53 pm
content: Quote from: wasedadoc on April 24, 2024, 11:13:36 amCan you help me to get equivalent inductor to order ? I think is this one 3.9mH
What component is this symbol - Page 1
Forum section: electronics / beginners

author: Noize
author_rank: Regular Contributor
timestamp: December 22, 2021, 08:33:54 pm
content: I have googled to find out what this symbol is to no avail? Look like 2 diodes connected cathode to cathode. If it is, is it something like 2 IN1418's?. It is from eurorack schematic for modular synth module input. The opamps run at plus and minus 12V. Thankyou.edit : anode to anode changed to cathode to cathode. oops

author: langwadt
author_rank: Super Contributor
timestamp: December 22, 2021, 08:37:10 pm
content: https://en.wikipedia.org/wiki/Transient-voltage-suppression_diode

author: wraper
author_rank: Unknown
timestamp: December 22, 2021, 08:41:14 pm
content: It should be a bidirectional TVS diode, although the symbol which is used is uncommon. My guess is whoever created that symbol looked into Wikipedia because it's the only place where I see it when googling.

author: Noize
author_rank: Regular Contributor
timestamp: December 22, 2021, 08:53:54 pm
content: Thanks for the reply. I searched mouser for tvs diodes and selected through their filters of 12V axial and found this candidate(Link below). Would this wor?. Signal will not be more than +-12V. Audio rates.SA12A-Bhttps://www.mouser.co.uk/ProductDetail/Littelfuse/SA12A-B?qs=zHiv0nsVGmqW1gPg8REsEA%3D%3D

author: rpiloverbd
author_rank: Regular Contributor
timestamp: January 05, 2022, 12:25:05 pm
content: Transient Voltage Suppression Diode :https://www.electronicshub.org/types-of-diodes/
What components testor to buy. Exemple: LCR TC1 vs LCR 7H? - Page 1
Forum section: electronics / beginners

author: renerelire
author_rank: Newbie
timestamp: April 05, 2019, 03:21:19 pm
content: Hi all!This is my first question here and my English is not the best.I'm a very beginner. Than means, I know almost nothing in electronic. I recently got an oscilloscope, two multi-meters, a signal generator, a power supply and I'm waiting for components like resistors, capacitors, diodes, diode lights, etc.. My goal is to be able to repair and modifying all kinds of devices and, I hope, eventually creating things.I wonder what components tester to buy? I'd like to have the most complete and precise one. I prefer to pay a little more than to have to buy several cheap units.I have spent quit a long time on Youtube but I'm still lost.I have an eye on theLCR TC1and onLCR 7H.I tried to compare the specifications but I'm confuse.TheLCR 7His more expensive but I'm not sure if that means it is the newer version of this device and if it is the best choice between those two.For instance:TheTC1does this: Zener Diode:Transistor Detect Area: 0.01-4.5V ; Zener Diode Detect Area: 0.01-30Vand the7Hdoes this: Automatic detection of zener diode（0.01-20V

author: LPS
author_rank: Contributor
timestamp: February 15, 2020, 02:19:50 pm
content: Hi,Don't know if you are still interested in the topic, there is a big thread on this topic that will answer your question.https://www.eevblog.com/forum/testgear/$20-lcr-esr-transistor-checker-project/6100/thanksLen

author: SkyMaster
author_rank: Frequent Contributor
timestamp: February 16, 2020, 03:47:19 am
content: Allô renerelire,You could look at the BSIDE ESR02 Pro.It is in the same price range as the two models you already looked at.

author: Jwillis
author_rank: Super Contributor
timestamp: February 16, 2020, 07:54:22 am
content: The TC1 and the 7H both use the Atmega324PA. I've search both and both Zener ratings are the same. Zener Diode Detect Area: 0.01-30V . Could be just a typo on the description for the 7H.
What connectors are best? - Page 1
Forum section: electronics / beginners

author: AndreyS
author_rank: Regular Contributor
timestamp: September 21, 2023, 12:05:47 pm
content: I'm not sure whether I've picked right subforum for this thread, sorry if notThe question is not about a manufacturer. What type of the connectors are most superior?The upper left contestant isWST I39601BS-2.The bottom right isJST SVH-21T-P1.1.In my opinion the bottom one is better because it touches the pin on both sides and the tension is not relying on plastic connector.What are your thoughts? Any even better connector?

author: jpanhalt
author_rank: Super Contributor
timestamp: September 21, 2023, 12:22:04 pm
content: I prefer a contact that has a spring action. Examples are the "Berg" (see:https://en.wikipedia.org/wiki/Berg_connector)* and Tiger Eye discrete types. This link shows the latter version vs. tuning fork. Tiger Buy is a "tuning fork" contact, which can easily be spread and loosens with multiple insertions.https://www.samtec.com/contact-systems/One thing to look for is contact "insertion cycles." That number can vary from a relative few (e.g., 10 to 40) to thousands as one finds with USB connectors. Unfortunately, one often has to do a lot of digging to find that specification for a particular connector.The other problem, as you have probably, found is the huge number of connector types.*Berg connectors (female connector) are commonly used for hobby servos.EDIT: Here's another link to the Berg type:https://www.connectortips.com/breakthrough-contact-design-spawned-500m-connector-company/

author: Kjelt
author_rank: Super Contributor
timestamp: September 21, 2023, 12:54:45 pm
content: It all depends on the purpose of the connector, the amount of amps and isolation (volts) it should be able to handle.For the best connectors I always look at examples in the industrial world and space / military applications.There you can find connectors that are way too expensive or even unusable for hobby since it requires special equipment to crimp and mount/dismount the connectors.The connectors you give as an example are made for as cheap as possible with reasonable quality.A cheaper simple boxheader connector would also suffice for those purposes.
What consideriations do you take in choosing a battery for a project? - Page 1
Forum section: electronics / beginners

author: Copernicus
author_rank: Newbie
timestamp: August 31, 2017, 10:09:21 pm
content: Ive been looking at battery options for my project, does it really matter what you choose? 4 AAA's or 2 AA's are basically the same capacity. 9V batterys seem on the low end for mAh capacity. For my project I need a 9V rail and a 40V rail . I could use a 9V battery for the 9V rail and a boost converter to get the 40V rail, or I could use 2 AAs and boost 1.5V -> 40V and use a voltage divider to get the 9V rail. Does the nominal voltage of the battery really matter? Any tips?Thanks!

author: Ian.M
author_rank: Super Contributor
timestamp: August 31, 2017, 10:29:25 pm
content: First ask how many watts you need and how long you need it for, then list your supply rails their current consumption, and whether or not they need to be regulated.Its more difficult to keep the losses low in a boost converter than in a buck converter due to the higher current in the switching transistor, so a higher battery voltage than the most loaded supply rail is often desirable.

author: Brumby
author_rank: Unknown
timestamp: August 31, 2017, 11:44:04 pm
content: Quote from: Ian.M on August 31, 2017, 10:29:25 pmThis is the first thing you need to do.I always get anxious about battery operated circuits and whether battery life will be adequate until those calculations are done. Wanting to run a 40V rail as part of that makes me wary - unless the current draw is going to be low.QuoteThis is the second step - and one key purpose is to address the issue of drooping voltages as the battery drains.
What could be this component - Page 1
Forum section: electronics / beginners

author: TestSubjectZero
author_rank: Contributor
timestamp: October 12, 2018, 09:06:10 pm
content: Hi guys,This is far fetch but I'm trying to identify what could be a component which fried.It not possible to read the making on the component. However, I can explain the setup. It sits between a the drain of the FDD4141 mosfet and the positive connection of a electronic speed controller.The circuit is feed 24v.Any ideas?Thanks

author: rsjsouza
author_rank: Super Contributor
timestamp: October 12, 2018, 09:09:49 pm
content: It is a SMD diode, but I can't read the marking very well.

author: TestSubjectZero
author_rank: Contributor
timestamp: October 12, 2018, 09:12:26 pm
content: I've tried read the making under a microscope but read there is nothing to be recovered.A small additional information, I've simply connected the mosfet drain to the positive pin of the ESC and everything works.So what type of diode could it be?

author: ataradov
author_rank: Super Contributor
timestamp: October 12, 2018, 10:09:22 pm
content: Given that there is a motor connector nearby, this is a flyback protection diode. I would not run for too long without replacing it.Find something beefy enough in this package, it should not matter all that much.

author: TestSubjectZero
author_rank: Contributor
timestamp: October 13, 2018, 03:53:30 pm
content: Quote from: ataradov on October 12, 2018, 10:09:22 pmIt doesn't seem to be connected in parallel to the ESC power pins, could it be something else?

author: ataradov
author_rank: Super Contributor
timestamp: October 13, 2018, 05:47:58 pm
content: Quote from: TestSubjectZero on October 13, 2018, 03:53:30 pmSure. In this case you need to draw the schematics of the surrounding area. Running without it is not a great solution anyway.
What could cause a clicking noise on a high power motor driver? - Page 1
Forum section: electronics / beginners

author: help_me_pick_username
author_rank: Contributor
timestamp: May 22, 2020, 12:04:38 am
content: My treadmill broke down recently, so I opened it up to take a look. The motor kind of stops and starts, in a sort of jerking motion, until it completely stops, where I have to hit stop on the console and then start again. (it could be worth noting that in the brief moment before the motor completely stops moving, the motor driver does supply enough power to overcome the initial belt friction, even when I'm standing on it).Anyway, there are some sounds coming from the motor driver board. When I first press start on the console, there is an immediate click somewhere on the driver board. The motor starts spinning up, before it starts jerking on and off. Usually, each time this jerks, there is a coinciding 'click' coming from the general direction of the driver board. My initial though was this could be caused by a relay, but there are no relays on the board that I can see. I kind of though the sound may have been coming from under the board, so I unscrewed it from the chassis, and there was this massive block of an EMI filter on the bottom. I couldn't confirm the noises were coming specifically from this part though. The clicking noise is actually a cross between a 'click' and a 'thud' and it's quite loud.As far as I can tell, there are no problems with the motor. I ran it off a bench power supply, and it spins up without too much effort. My PSU didn't have enough current capabilities to move the motor while I was standing on the belt, but I increased the voltage up to 30v, and the motor was moving smooth and fast. When I ran the motor controller without the motor actually connected, it ran fine (the status LED was blinking fast, meaning it was receiving a speed signal and it was providing power to the motor).At this point, I'm kind of stumped. There don't seem to be any components on the board burnt out or anything.What could be causing this clicking noise?
What could cause dc voltage on non-connected pins? - Page 1
Forum section: electronics / beginners

author: Andy-In_over_my_head
author_rank: Regular Contributor
timestamp: January 05, 2018, 04:53:41 am
content: So I made a little board for playing with 8 pin chips that have power top right and ground bottom left. I’m powered with 7805 to top right pin and the 3 pins below that are solo. However, I have 5v on pin 8, 2.73v on pin 7, 1.075v on pin 6 and .540v on pin 5. Nothing on ground or 2-4. Could flux residue carry voltage? I cleaned most off so I’m confused what is causing this.Thanks in advance for the help!

author: Peabody
author_rank: Super Contributor
timestamp: January 05, 2018, 05:02:50 am
content: Not sure what you mean by top right and bottom left. But the voltage that may be present on any pin could result from normal connections inside the chip. If you would tell us which 8-pin chip you have, perhaps someone who also has that chip could see if he gets the same readings.

author: Richard Crowley
author_rank: Super Contributor
timestamp: January 05, 2018, 05:14:48 am
content: Please learn how to identify the pins by number. "Top right" and "bottom left" mean nothing without proper context.Note also that all 8-pin chips are NOT all the same. So, a generic question like this is not valid.As @Peabody mentioned, what you are seeing is quite normal because of the circuitry inside your (unidentified) chip.

author: Inverted18650
author_rank: Frequent Contributor
timestamp: January 05, 2018, 05:30:09 am
content: Quote from: Andy-In_over_my_head on January 05, 2018, 04:53:41 amhttps://www.google.com/search?q=is+solder+flux+conductive&oq=is+flux+conduct&aqs=chrome.2.0j69i57j0l4.5105j0j7&sourceid=chrome&ie=UTF-8

author: Andy-In_over_my_head
author_rank: Regular Contributor
timestamp: January 05, 2018, 07:04:30 am
content: I think I wrote this wrong. There’s no chip. There’s no specific PIN numbers but if I had to use pins, an example would attiny85 with Vcc as pin 8 and ground as pin 4. Pin 8-7 has 5 megs resistance, 8-6 = 10 meg, 8-5 = 22 meg. I get the voltages but why? I put my BK precision 879B probes into the flux I have and got no resistance at any distance from each other. So on basic perf board, what am I missing?And I’m sorry if I can’t type out the perfect explanation. I posted in a beginner section with a beginner problem. I know enough to get by with my own projects but just haven’t had this particular problem before. I think I made this confusing by not being forward saying there’s not chip on this board. A 7805 to put power and ground to opposite corners on an empty 8 pin socket.

author: Andy-In_over_my_head
author_rank: Regular Contributor
timestamp: January 05, 2018, 07:07:33 am
content: Okay. I understand then. I moved to Hawaii this pst year and it’s very humid. So after I get the flux super hot and with the humidity it’s became conductive. Makes sense why I get no resistances putting the leads into the flux.
What current is this transformer rated at? - Page 1
Forum section: electronics / beginners

author: Chris Wilson
author_rank: Super Contributor
timestamp: June 18, 2013, 03:49:42 pm
content: Is there enough info to say what amperage this transformer is rated at if I try and pull either circa 13 volts, or circa 6 volts for valve filaments please? I need 12.6 and 6.3 actually, but can tweak with one of those slider type ceramic wire wound resistors in the primary I think? Thanks. If you can briefly tell me how you worked it out I would be grateful!

author: M. András
author_rank: Super Contributor
timestamp: June 18, 2013, 03:58:00 pm
content: total 124va

author: Rufus
author_rank: Super Contributor
timestamp: June 18, 2013, 04:08:03 pm
content: Quote from: Chris Wilson on June 18, 2013, 03:49:42 pm1.55A worked out by readingIt looks like there are 8 secondaries two of each 1,3,9, and 27v. If you used them all at 1.55A that makes the shown 124VA.The most current you can have is 1.55A or 3.1A if you put 2 secondaries in parallel. 1+3+9 would give you 13v and you could parallel.

author: jimmc
author_rank: Frequent Contributor
timestamp: June 18, 2013, 07:02:29 pm
content: Looks like a bigger brother of the old Radiospares 'Universal Rec. Trans.'Which would confirm 1.55A per winding.Jim

author: Chris Wilson
author_rank: Super Contributor
timestamp: June 19, 2013, 12:19:09 am
content: OK, thanks for the info and attachment, got it sussed now, cheers!My misunderstanding was I assumed 124VA applied to a single winding, as in I could series say the two 3 volt windings to give 6 volts. Then I was dividing 124 by 6 to get a current ability of 20 amps. I was thinking this is a mighty powerful little transformer. I now of course see it's the rating for ALL the winding together, so 1 + 3 + 9 + 27 = 40 volts. Series the two sets of series windings and you get 80 volts. 124 divided by 80 = 1.55 Amps, as the top panel saysThe figure of 124 VA applies when *All* the windings are used together....
What current/Voltage to use with relay if only impedance given? - Page 1
Forum section: electronics / beginners

author: primegaps
author_rank: Contributor
timestamp: April 01, 2018, 10:35:24 am
content: I've got several of these ice cube relays, many of which list you a voltage which is sufficient to close the relay.Some of then instead list a current and a resistance, from which you calculate the appropriate voltage. I suppose this makes more sense since it gives you the current needed, whereas if just the voltage is listed, it is possible your power supply may not be able to deliver the current needed to close/open the relay (unlikely i guess).But I also have a few relays that just list the resistance. In this case, 5000 Ohms. How do i know what voltage/ current to run these relays at?thanks!

author: fourtytwo42
author_rank: Super Contributor
timestamp: April 01, 2018, 10:57:52 am
content: You could work it out from the operating power required however this varies widely depending on the size of the relay, number of contacts and if it has a bias magnet (usualy indicated by having polarity markings). Posting a picture might help along with something to scale it.

author: primegaps
author_rank: Contributor
timestamp: April 01, 2018, 12:18:56 pm
content: Here is a picture of the relay.I thoguht I had included an image earlier.

author: eblc1388
author_rank: Frequent Contributor
timestamp: April 01, 2018, 02:14:03 pm
content: Quote from: primegaps on April 01, 2018, 10:35:24 amYou can't, unless you look at the data sheet.From the Potter & Brumfield KCP relay data sheet, it states that "each pole of contact" requires 125mW to operate. Your's KP-11 is of a two-pole construction so it requires 250mW nominal power to operate.The coil voltage works out to be .25Wx5000=V^2, and V=35.36V or 36V, and the current to be around 7mA.I guess only the coil resistance is given because this is a sensitive current relay and user can use it on other voltages by placing a resistor in series.

author: bitwelder
author_rank: Super Contributor
timestamp: April 01, 2018, 03:24:45 pm
content: Google Books finds a schematic diagram from USGS that uses the KCP 11 with a 15V supply:https://books.google.fi/books?id=ck3wAAAAMAAJ&lpg=PA96&ots=qzbj8Et8YT&pg=PA96#v=onepage&q&f=false

author: Benta
author_rank: Super Contributor
timestamp: April 01, 2018, 04:51:03 pm
content: My rule of thumb:Increase voltage over the coil until it pulls in the contacts 100%. Then use double that voltage for operation.
What degree/course and what uni/other education did David l Jones for EE ?  - Page 1
Forum section: electronics / beginners

author: Maxwell-X
author_rank: Newbie
timestamp: September 24, 2018, 11:19:20 am
content: As above ^

author: NivagSwerdna
author_rank: Super Contributor
timestamp: September 24, 2018, 12:49:50 pm
content: http://www.artofinternetdating.com/specifically...http://www.artofinternetdating.com/author.htmOMG that is such a great picture

author: Mr. Scram
author_rank: Super Contributor
timestamp: September 24, 2018, 12:56:58 pm
content: Quote from: NivagSwerdna on September 24, 2018, 12:49:50 pmThat's absolutely hilarious. I've never seen that before. I also like the reference to The Art of Electronics.

author: NivagSwerdna
author_rank: Super Contributor
timestamp: September 24, 2018, 01:32:03 pm
content: https://au.linkedin.com/in/davidjoneselectronicsNational Institute of Dramatic Art (NIDA)explains a lot.

author: coppercone2
author_rank: Super Contributor
timestamp: September 24, 2018, 01:44:49 pm
content: that suit picture is ridiculous in the best way possible. does anyone feel like they never tried before when they look at that?you know what would be interesting, if dave jones talked about the effect of swiping on tindternet dating. supposedly it has a disastrous effect but I am sure we are all too busy to know the ramifications
What determines resistors power ratings if not physical size? - Page 1
Forum section: electronics / beginners

author: dentaku
author_rank: Frequent Contributor
timestamp: July 18, 2014, 11:08:51 pm
content: I'm wondering how the power rating of resistors relates to their size.I got some 100K 500mW 1% resistors recently and they're tiny compared to the regular resistors I'm used to which are mostly all 250mW.If it's not their size then what determines resistors power ratings?

author: rob77
author_rank: Super Contributor
timestamp: July 18, 2014, 11:18:05 pm
content: many factors.material used - some materials can withstand higher temperaturessurface area - the bigger the surface the more heat can be dissipatedthermal resistance of the materials - if the material is better conducting heat, then more heat can be dissipated though the leads, or PCB tracesbut as rule of thumb... the bigger the resistor, the higher the power rating is.

author: mazurov
author_rank: Frequent Contributor
timestamp: July 18, 2014, 11:40:57 pm
content: Temperature coefficient of material is also a factor. For example, copper makes a good conductor but poor resistor since its TC is almost 0.4% per degree C. On the other hand, Vishay's WSLP2726 all-metal beauties with cross-section similar to 16ga wire are rated only 5-7W. They are made of nichrome - an alloy with TC 10 times smaller than copper but much higher resistance.

author: dentaku
author_rank: Frequent Contributor
timestamp: July 19, 2014, 12:19:46 am
content: Quote from: mazurov on July 18, 2014, 11:40:57 pmThe ones I got are Vishay metal film resistors. I was amazed at how small they are and that they where 500mWhttp://canada.newark.com/vishay-bc-components/sfr16s0001003fr500/resistor-metal-film-100kohm-500mw/dp/05R0211

author: T3sl4co1l
author_rank: Super Contributor
timestamp: July 19, 2014, 08:07:38 pm
content: Chip resistors are almost uniformly rated for 0.1W: 0402 to 0805, very roughly. The limiting factor is thermal diffusion, which has a sqrt(length) proportion: if the aspect ratio is not changed with size, then the total dissipation varies relatively slowly with size.They also assume a naked chip resistor with thin traces; you can get much more from an 0603 with heavy copper pours around.TH resistors vary, but temperature of the materials is probably the biggest factor. Epoxy vs. silicone enamel (or ceramic, or vitreous!), tinned vs. welded connections, etc. And whether they guarantee tempco or tolerance within the temp range, or what.Tim
What diode is this? - Page 1
Forum section: electronics / beginners

author: fbatista
author_rank: Newbie
timestamp: May 31, 2017, 05:10:57 pm
content: Hi folks,I have tried a couple of days to find the datasheet for this diode but had no luck.I know it is a diode, probably a zener because of the package.It was being used in a relay circuit connecting both terminals of the coil of the relay from a microwave oven. Could also be a flywheel diode because of that.The relay is a 12VDC coil that can handle 16 A 250 VAC. Also, I know that the coil resistance is 200 ohms and the rated current is 58 mA. (https://media.digikey.com/pdf/Data%20Sheets/Omron%20PDFs/G5J.pdf)About the diode:Looks like a zener, but the writings on it are a bit different. Holding the diode horizontally:______----------|______|----------R3| <-----I don't know if it's a 1 ou lI also don't know the order of the letters. And it has that bold line to indicate polarity.Could someone help me with that? I'm going mad.

author: james_s
author_rank: Super Contributor
timestamp: May 31, 2017, 05:56:50 pm
content: If it's across the relay coil it's probably just a snubber diode. An ordinary 1N4007 ought to work.

author: fbatista
author_rank: Newbie
timestamp: May 31, 2017, 06:35:12 pm
content: Since I already gave up trying to find exactly the same, I will solder the 1n4007 to the board and actually test its functionality.

author: fbatista
author_rank: Newbie
timestamp: May 31, 2017, 07:23:34 pm
content: It worked just fine! Thanks
What diode to choose as replacement ? - Page 1
Forum section: electronics / beginners

author: Sjokolade
author_rank: Regular Contributor
timestamp: January 17, 2025, 04:18:04 pm
content: On this board D5 and D12 measures as open - what sod-323 package diode do I replace these with ?I had a look on aliexpress but I did not find any with the 2A marking.

author: Andree Henkel
author_rank: Regular Contributor
timestamp: January 17, 2025, 04:50:35 pm
content: as there are several of them, and close to board edge to connectors and to switch and one side is to (likely ground) polygon. My guess is, they are likely there for ESD protection or TVS diodes. I didn´t find the marking either.Here result for TVS diodes in SOD-323:https://www.digikey.de/de/products/filter/%C3%BCberspannungsbegrenzer-tvs/tvs-dioden/144?s=N4IgjCBcoGwJxVAYygMwIYBsDOBTANCAPZQDaIALAAxwDMdIAuoQA4AuUIAymwE4CWAOwDmIAL6EwAJjgRoIFJAw4CxMpSoUAHBQSFq2gKxSQ%2BzVsO1TGoxWtawMY1vtgKlw9YMXPzEO04eARFxMTEgAbut how to find a suiting one:*type: unidirectional or bidirectional: looks like they are bidirectional, some are with the "2" at the polygon, some with the "A", but you can check, desolder one, unidirectional has a diode drop in one direction, Zener voltage in other. Biderectional is Zener in both orientations, also there is no Cathode marking, so i guess it is another hint for bidirectional.Next you need supply voltage of your logic the protected signals are connected to. Say 3.3VSo TVS bidirectional for 3.3V in SOD-323 narrows down to:https://www.digikey.de/de/products/filter/%C3%BCberspannungsbegrenzer-tvs/tvs-dioden/144?s=N4IgjCBcoGwJxVAYygMwIYBsDOBTANCAPZQDaIALAAxwDMdIAuoQA4AuUIAymwE4CWAOwDmIAL6EA7DAjQQKSBhwFiZcJIpgwAVhCEwGsACYjTVh0jc%2BQ0RPBG4s5Gix5CJSOWoUAHBQSE3j7apoFUvtq0epThwRTRPmAwIT4JYBSRumERuswg7Jw8AiLi%2BpK0VIjyLsruahB5BZYAIkQArgBGmLil4HA%2BCHIKSm6qniCVjHYAtFFDUHxtKh7kYJMzpvOQi8tqWSAIU2JiQA1. Hit PESD3V3 by nexperia is one I use myself in my designs for this purpose

author: Andree Henkel
author_rank: Regular Contributor
timestamp: January 17, 2025, 05:08:55 pm
content: If you measured them open, I guess it´s a bad sign. In ESD event the TVS diode should limit the voltage at the digital signal it is protecting, so the IC´s don´t get damaged. They usually have some ESD protection on their own like HBM (Human Body Model) 2kV, but the TVS diode should work like up to HBM 15kV. In ESD event the diode goes into avalanche breakdown to limit the voltage at the IC´s to their protection level.But after slighter ESD events the TVS diode should still be ok, so if they are measuring open, they no longer could do their duty and probably defects down the line at some IC occured.So good luck...

author: Sjokolade
author_rank: Regular Contributor
timestamp: January 18, 2025, 02:47:12 pm
content: Thanks for you help - I will just replace this board instead of buying diodes and still have defects.
what diode  to use 7 - Page 1
Forum section: electronics / beginners

author: tecnovist
author_rank: Newbie
timestamp: July 29, 2019, 09:03:36 am
content: cool thanks i need to polarity protect my phone battery car charger a its no jumper leads if i get get it round wrong way it kills it .. .i need to know the best diode to use and how it where to place it .. thanks

author: CiscERsang
author_rank: Regular Contributor
timestamp: July 29, 2019, 09:41:59 am
content: Quote from: tecnovist on July 29, 2019, 09:03:36 amhttps://www.vishay.com/docs/88715/sb110.pdf

author: Flump
author_rank: Frequent Contributor
timestamp: July 29, 2019, 11:17:45 am
content: I miss Afrotechmods his videos were always easy to understand and well made.

author: Zero999
author_rank: Super Contributor
timestamp: July 29, 2019, 12:39:21 pm
content: Use a Schottky diode. It will drop more voltage, than a MOSFET, but is much easier to use. I'd recommend the 1N5820/1N5821/1N5822, simply because they're cheap.https://www.vishay.com/docs/88526/1n5820.pdf
what dip socket to order - Page 1
Forum section: electronics / beginners

author: m3vuv
author_rank: Super Contributor
timestamp: November 26, 2021, 05:18:50 am
content: Hi all ive a DS1230Y-100 Integrated Circuit i want to fit a socket for,does anyone know what i should order?,tia

author: retiredfeline
author_rank: Frequent Contributor
timestamp: November 26, 2021, 06:18:32 am
content: It's a standard 28 pin 0.6" socket you want, but the package extends beyond the normal DIP boundary so leave room on your PCB for that.

author: m3vuv
author_rank: Super Contributor
timestamp: November 26, 2021, 06:46:56 am
content: its to replace the nvram on an old 500meg hp scope,will have to see when it gets delivered,its my latest ebay buy.should be here this morning.
What display is this? - Page 1
Forum section: electronics / beginners

author: irondemigod
author_rank: Newbie
timestamp: September 22, 2023, 12:41:32 pm
content: Hi all!I got this display from an Alba car dvd player (the ones which strap onto the car seat headrest)I know the display is functional because it powers on and everything works except for the cd readerIt is a 7" wide LCD with a 26-pin ribbon cable coming out of it and two wires which i am guessing is for powerIt also has a thicker black cable attached to the metal case of the displayI want to know what type of display is this, and if there is any module i can use to use the display with microcontrollers or an hdmi inputI have attached close-up pictures of the display and the second display part of the Alba setThanks!

author: DavidAlfa
author_rank: Super Contributor
timestamp: September 22, 2023, 01:51:41 pm
content: Nah these lcds controller-less, parallel bus, being 26pin it's probably 8 bit bus, you'll need a LCD driver board, or mcu with lcd driver and plenty of RAM.Finding the pinout is another issue.

author: Haenk
author_rank: Super Contributor
timestamp: September 22, 2023, 01:53:24 pm
content: So, that's a Hannstar display, which should should narrow down the search.Maybe remove the frame and check if there is another hint on the model.

author: amyk
author_rank: Super Contributor
timestamp: September 23, 2023, 01:33:59 am
content: Look up "26 pin LCD" and one model you'll find is the A070FW03. Pinout seems to match - pins 10 and 11 are connected together on yours, and on that one they're also both VCOM. The thicker traces for power also line up. It's an analog LCD. I looked for other 7" analog LCDs and found AT070TN07, HSD070I651, and LB070W02-TMJ2 - same pinout. I think it's safe to assume that any 26-pin LCD with pins 10 and 11 connected together should have this same interface.
What do a 10MHz output signal looks like? - Page 1
Forum section: electronics / beginners

author: FriedMule
author_rank: Frequent Contributor
timestamp: June 05, 2020, 01:25:26 am
content: A 10MHz frequency standard, out some standard signal in 10MHz and in 1Hz, how do that signal look like, is it a square wave, spike or?Am trying to build a simple counter that counts every 1Hz.

author: ArthurDent
author_rank: Super Contributor
timestamp: June 05, 2020, 01:56:59 am
content: The answer is- it depends.I have quite a few instruments that output 10Mhz, some output sine, some square wave. It depends what you're using them for. Here is a really nice divider that outputs synchronized square waves that are nice for some timing applications where the leading edge of your decade outputs need to be synched.http://www.perdrix.co.uk/FrequencyDivider/Frequency%20Divider%202.1.pdf

author: Cubdriver
author_rank: Unknown
timestamp: June 05, 2020, 06:20:32 am
content: This is the output of a Lucent RFG-M-RB Rubidium frequency standard being fed through a 50 ohm feedthrough terminator into an AC coupled scope.A few photos of the setup are here:https://pmanning.smugmug.com/Electronics/Lucent-RFG-M-RB-Rubidium-Frequency-StandardThe more wonky looking waveform in the gallery photo before the one I linked to here was what the waveform looked like when the frequency counter was connected in parallel with the scope through a tee at the Rb standard's output jack.-Pat

author: FriedMule
author_rank: Frequent Contributor
timestamp: June 05, 2020, 09:38:54 am
content: Thank you both! So it does not matter on how the output signal are? A circuit can easily trigger by it anyway?I am just a bit confused because a sinusoidal signal is every voltage between the rails, while a square wave is on or off.By the way: WOW!!, what a setup, that's gear porn when it's best! :-)

author: TimFox
author_rank: Super Contributor
timestamp: June 05, 2020, 01:28:42 pm
content: Real square waves have finite transition times between the two levels, with not-completely-flat signal at each level, as shown in the oscilloscope above. Therefore, they also cover the range between two extremes.Consistent triggering is improved when the slope dV/dt increases at the trigger level, giving a well-defined time for the trigger.

author: David Hess
author_rank: Super Contributor
timestamp: June 05, 2020, 06:21:33 pm
content: The waveform can vary widely depending on the implementation. Sine waves, digital logic outputs, and filtered digital logic outputs are common. More sophisticated designs might use a digital logic output to control current switches which allows for very clean and controlled edges.

author: tkamiya
author_rank: Super Contributor
timestamp: June 07, 2020, 03:01:59 am
content: Most of my equipment (mostly HP) specify sine wave 10MHz. Most of them; however, has an internal circuitry to convert sine to square.My lab standard 10MHz signal is a 10MHz sine wave.
WHat do guitar distortion circuits sound like with ? - Page 1
Forum section: electronics / beginners

author: lordvader88
author_rank: Frequent Contributor
timestamp: February 16, 2019, 03:52:53 pm
content: I need to buy some better op-amps overall, but for now I have some LM741, LM358, LM386. So for fun and math homework I should build some guitar pedal circuits with those. I'm wondering, what how good/bad they actually sound ?? I should check utube, but then again, maybe not. And of I have a guitar, and scopes and probes/etc, I never checked any of my guitars on the scope before.I really should experiment more, rather than just collecting parts.And to go from start to finish, through such a circuit, with say; 1 op-amp stage stage, 1 tone stage, 1 JFET stage, and calculate the ideal situations, I can't do that yet. Or can I ? I can do basic op-amps, with beginner level ODE's, and complex numbers. I need to do more ODE before I re-do Laplace transforms. I don't formally know AC analysis on filters either.I've been off on a math/physics holiday from here and physical electronics. And it's all falling together perfectly.Do I need Fourier series or functions/etc/? I've toyed with them over the years, but never delved in, I can't really remember any main eqn of them.

author: unitedatoms
author_rank: Frequent Contributor
timestamp: February 16, 2019, 04:03:01 pm
content: one look at it is that the worse (non linear) the component is the better it sounds. I never did anything with sound generation, other than connecting speaker to lab generator. The sound of perfect sinusoid is terrible, thats all I know.

author: UprightCitizen
author_rank: Newbie
timestamp: February 18, 2019, 07:41:19 pm
content: Thing is, as mentioned, distortion pedals that you are talking about are highly non linear. This means your ODE's, laplace etc is probably not going to do anything for you. So it might not be the best project based on what you seem to be looking for.

author: Refrigerator
author_rank: Super Contributor
timestamp: February 18, 2019, 07:45:50 pm
content: LM358 is pretty slow with ok zero crossing, works for low frequencies. LM386 sounds pretty funky when you overdrive it.

author: Jr460
author_rank: Regular Contributor
timestamp: February 18, 2019, 08:18:02 pm
content: Quote from: unitedatoms on February 16, 2019, 04:03:01 pmNot exactly true. A guitar into something that hard clips it into almost square wave doesn't sound good. Makes for a very ratty, rather big full sound. In general people tend to find odd harmonics in distortion as less musical.Of course everything has it's place. If you are playing simple chords, those higher odd harmonics make things more complex, for example taking a C and making it something like a C 7#9. Now if you really what very specific higher order chords, a bunch of distortion may be the last thing you want. Or if you are Jimmy Hendrix, yea play the 7#9 with heavy crunch.
What do I need to think about moving away from Arduino? - Page 1
Forum section: electronics / beginners

author: jrozner
author_rank: Contributor
timestamp: December 27, 2016, 02:27:16 am
content: I'm laying out my first board in EAGLE and using an ATMega64A. I've prototyped it using an Arduino mega (and handful of other components) but am wondering what sorts of supporting components I need to think about when moving away from an Arduino platform and to my own custom board? I've jumped around in the data sheet and found some information about handling unused I/O pins, programming (for various methods), various special pins (RESET, etc.), and power limits but haven't found a suggested example wiring diagram with respect to supplying power or anything other signals like I've seen in some others. Coming from an Arduino I've never had to worry about most of this and just hoping to minimize mistakes that could land me with boards that don't work.

author: rob77
author_rank: Super Contributor
timestamp: December 27, 2016, 02:34:35 am
content: power, decoupling, clock, ISP header - that's a bare minimum for any ATmega, and that's basically what you find on any arduino board (of course most arduino bards also has a usb-serial connected to 1st serial port of atmega)

author: ataradov
author_rank: Super Contributor
timestamp: December 27, 2016, 02:36:37 am
content: Just look at Arduino schematic and replicate it to the extent necessary for your project. In general, to have a self-sufficient ATmega board all you really need is an ISP programming connector, a few bypass caps on power supply lines, and a pull-up resistor on a reset pin.

author: GBowes
author_rank: Contributor
timestamp: December 27, 2016, 03:39:05 am
content: You cannot go wrong following Atmel's recommendations. See app notes AVR042 and possibly AVR040 if you have EMC concerns or requirements.http://www.atmel.com/images/atmel-2521-avr-hardware-design-considerations_applicationnote_avr042.pdfGrahamQuote from: jrozner on December 27, 2016, 02:27:16 am

author: jrozner
author_rank: Contributor
timestamp: December 27, 2016, 04:23:13 am
content: This is perfect! Thanks, I didn't know this existed.Quote from: GBowes on December 27, 2016, 03:39:05 am
what do these symbols mean from an analog panel meter - Page 1
Forum section: electronics / beginners

author: jmgallag
author_rank: Newbie
timestamp: November 03, 2018, 01:28:05 am
content: The 200 ua is obvious, but I don't get what the other symbols mean. Anyone?Thanks

author: ArthurDent
author_rank: Super Contributor
timestamp: November 03, 2018, 01:38:02 am
content: Have you tried googling the maker and model number to check for info?

author: jmgallag
author_rank: Newbie
timestamp: November 03, 2018, 01:41:38 am
content: Unfortunately, there is no manufacturer info on the meter.

author: ataradov
author_rank: Super Contributor
timestamp: November 03, 2018, 01:58:06 am
content: First one means "moving coil".1.5 is probably 1.5% accuracy, although I'm not sure.The last one is orientation of calibration (and expected use orientation). That specific means that it was calibrate in horizontal orientation.Those symbols are universal, but I'm failing to find a complete table. There is one that google images comes up with, but it is in German.EDIT: It looks like they are universal to a German DIN standard, which explains information in German. Although Soviet meters had similar markings.

author: jmgallag
author_rank: Newbie
timestamp: November 03, 2018, 03:21:14 am
content: Thanks all, I knew I could get the answer here!

author: pelule
author_rank: Frequent Contributor
timestamp: November 03, 2018, 12:55:36 pm
content: QuoteThats correct.All that signs are defined by the German standard DIN 43780 (Electrical measuring instruments; direct acting indicating electrical measuring instruments and their accessories). Its withdrawn and replaced by EN 60051-1Refer also to:https://www.eevblog.com/forum/testgear/exploring-the-symbols-on-a-analog-multimeter-quiz/Signs from the left to the right:- moving coil with permanent magnet- accuracy class in percent (thus 1.5% accuracy)- horizontal scale/PeLuLe
What do you guys think of the new Framework laptop? - Page 1
Forum section: electronics / beginners

author: LoveLaika
author_rank: Frequent Contributor
timestamp: April 25, 2023, 02:46:34 pm
content: With the new Framework 16 Laptop coming, I was wondering what you thought of it, or more generally, the Framework laptop as a whole? For those not in the loop, here's a video showcasing the upcoming product.Personally, I hope this project lasts a long time. The idea behind it is cool, and I like the support that's already been given to it in theirGithub repos. Plus, I have to admit that Linus's enthusiasm for the new laptop is contagious. It does seem pretty cool how he was able to add the modular inputs. At least he's having fun with it.On the other hand, it's expensive. I'm also reminded ofProject Arawhich seemed cool but got shelved. For all the work that's been done with Framework already, I hope it lasts longer.Maybe...as a supplemental question, what do you guys think of the expansion bay that was mentioned? It seems pretty big, but what do you think you can design there that would be great for engineers? Linus mentioned that you could design something like an oscilloscope in that bay, but that's out of my depth of whether it could be done or not. Still, I thought the idea was pretty cool.

author: TopQuark
author_rank: Frequent Contributor
timestamp: April 25, 2023, 03:27:32 pm
content: Love it, would gladly pay for one, but not available where I liveI have used my thinkpad x1 carbon Gen 5 for 6 years, dropped it a few times from height, had a 15kg robot fall on it once, punching a hole through the lid. I recently swapped all the exterior casing/shell, and I'm happily using it like a new laptop again.If in addition to being able to swap the casing, I can update the guts as well, that would make it my dream laptop.edit: btw, I think this thread belongs to general technical chat, not in the beginners section.

author: LoveLaika
author_rank: Frequent Contributor
timestamp: April 25, 2023, 05:01:47 pm
content: Thanks for replying. I wasn't sure where to post this, so I thought it would fit here. Should I delete this and move it to the other forum?

author: TopQuark
author_rank: Frequent Contributor
timestamp: April 26, 2023, 04:00:53 am
content: Don't worry too much about it, if it bothers the forum mods enough, they will move it to the correct board.

author: Ed.Kloonk
author_rank: Super Contributor
timestamp: April 26, 2023, 05:20:11 am
content: Perfectly good Computers section of the forum.Some computer people are known to lurk there whilst steering clear of general chat.https://www.eevblog.com/forum/general-computing/