hybridfree/eevblog-posts huggingface dataset:
Partial instructions for soldering and rework station - Page 1
Forum section: electronics / beginners

author: fixit7
author_rank: Regular Contributor
timestamp: June 26, 2019, 01:32:19 am
content: I bought this and it only came with partial instructions.https://imgur.com/a/BjaHghCWhat is the black at the very bottom with the black know and what looks like a small goal post?Are those rework tips used for desoldering components?I know what the soldering braid is used for.Thanks.Andy

author: JustMeHere
author_rank: Frequent Contributor
timestamp: June 26, 2019, 02:05:08 am
content: The goal posts can help you position things, but a set of fine tweezers will get your further.

author: JustMeHere
author_rank: Frequent Contributor
timestamp: June 26, 2019, 02:06:34 am
content: The hot air can be used for soldering and desoldering. It helps a ton with SMD.

author: Shock
author_rank: Super Contributor
timestamp: June 26, 2019, 03:00:44 pm
content: It's for lifting ICs off the PCB without damaging traces, you can put a very light lift tension on it and when the solder is molten it pops the IC off. It's probably low quality, you could improve on it making your own handle.

author: fixit7
author_rank: Regular Contributor
timestamp: June 26, 2019, 10:23:24 pm
content: Thanks.I really like the ability to dial in higher temperatures.I needed to solder some 12 gauge wire and had to dial it up to 480.The instructions had very few typos.I was impressed.
Parts Catalogs,who has the best one? - Page 1
Forum section: electronics / beginners

author: RobertBG
author_rank: Regular Contributor
timestamp: January 03, 2016, 09:30:40 pm
content: I personally hate going back and forth between web pages and I really like old fashioned paper at times and I was wondering who has the best catalog?I guess we could break it into free and paid sections.I just received one from Element 14 and it makes a NYC phone book look smallbut I'm open to others.Thanks

author: tautech
author_rank: Super Contributor
timestamp: January 03, 2016, 09:35:12 pm
content: RS do a monster one too.

author: SeanB
author_rank: Super Contributor
timestamp: January 03, 2016, 09:53:14 pm
content: RS only offer the paper one as an option, you pay postage. I do keep old ones, makes it easy to find stuff they have which is not easy on the website. Then you look up the part number to confirm price and delivery. Almost have enough to make a footstool with.

author: RobertBG
author_rank: Regular Contributor
timestamp: January 03, 2016, 10:23:03 pm
content: Thanks,I'll definitely take a look and see if they'll throw one in a order.I honestly forgot that I filled out a request for the Newark/Element 14 one and I was truly surprised to see it on my doorstep.I actually thought it was a box of parts at firstWhen I ordered it I just expected the bare minimum 1-200 pages or so that most companies do these days and not a close to 2500 page footstool.I've only ordered a few things from them but definitely no complaints thus far.At work I have 3 monitors so it isnt too bad but at home I just get lost on the websites even looking at simple things like connectors.Thanks again
Parts crossref help needed 2sk... vs IRF - Page 1
Forum section: electronics / beginners

author: EEVPiobee
author_rank: Contributor
timestamp: February 24, 2014, 06:56:02 am
content: Hello there... Here is my problem...I'm fixing a Samsung TV for a friend and since it's a LED TV, Power supply is out (deuah.. they all do that!)After a quick sweep, I realised some FETs are dead as well as some diodes...Now... anyone know the cross ref of these? I figured out one acceptable crossref partswap, (which I have on hand) but none of the others yet...Here it is:K3561 (Datasheet really looks the same as IRF840)K3568 (I can't barely see a functionnal difference from the previous apart from the Vgs ampage)STR6252 (nope it's not strw6252)N1156 something (no results found on the internet... I'll double check and note edit this post to the rightAnything else from vishay? Fairchild?
Parts Kits / Grab Bags - Page 1
Forum section: electronics / beginners

author: OsiViper
author_rank: Contributor
timestamp: March 08, 2014, 05:09:59 am
content: I have always loved electronics and tinkering with stuff. As a kid I always took my toys and electronics apart to see how they worked.Always wanted to get into the electronics field, but out of high school I ended up going for another passion which was cooking. Got a degree in that and worked for a long time. Just recently I decided I wanted to start learning more about electronics and started going to school.Have always messed around with basic circuits, arduino, etc.. But lately I want to start tinkering more and more and make various circuits, see how they work, take it apart and do it again. But I need parts.. I managed to get my hands on some grab bags for resistors, diodes, capacitors, and various transistors.Anyhow, long story short I am looking for a place that has good parts kits or grab bags, specifically for various IC's and other components.I've looked at a place called Futurlec which seems to have a good variety of pieces in their kits for a really good price. But any review i've read seems bad for them.If there aren't any other places that have good assortments of them, which ones would be best to get a few of to experiment with and where would be the best place?Right now i am not looking for SMD stuff yet because don't have the boards to mess with that.Anyhow, thanks in advance for the advice

author: Kappes Buur
author_rank: Regular Contributor
timestamp: March 08, 2014, 06:18:29 am
content: A good place ishttp://www.goldmine-elec-products.com/They seem to have new stuff every month.

author: OsiViper
author_rank: Contributor
timestamp: March 08, 2014, 06:42:45 am
content: Quote from: wilfred on March 08, 2014, 06:31:25 amThought I did that. Sorry.It's updated now, I live in the USA

author: OsiViper
author_rank: Contributor
timestamp: March 08, 2014, 07:08:26 am
content: Quote from: Kappes Buur on March 08, 2014, 06:18:29 amWow thanks. Their surprise boxes look like they would be cool along with some other assortments

author: T3sl4co1l
author_rank: Super Contributor
timestamp: March 08, 2014, 10:38:59 am
content: Also,http://www.allelectronics.com/Tim
Parts resources - Page 1
Forum section: electronics / beginners

author: warnberg
author_rank: Contributor
timestamp: January 19, 2016, 02:22:40 pm
content: Not sure if this belongs here or in another section..I'm looking for a good online source for parts... i.e. Capacitors, Diodes, Resisters, etc... Where do you get your parts?ThanksDave

author: JacquesBBB
author_rank: Frequent Contributor
timestamp: January 19, 2016, 02:51:16 pm
content: Mouser, rs components and ebay

author: thejoggingmat
author_rank: Regular Contributor
timestamp: January 19, 2016, 03:01:03 pm
content: I'm not sure about you, but for me the best place (considering) is evilBay. The only electronics 'mall' in my country imports the exact same chips from China and sells them at heavily inflated prices that will make items sold by the late RadioShack look intensely cheap.For instance, a 555 locally costs a dollar a pop whilst it costs the same for around 20 from China, shipping included.

author: Audioguru
author_rank: Super Contributor
timestamp: January 19, 2016, 03:49:32 pm
content: In United States, Digikey and Newark are good suppliers of electronic parts. ebay sells cheap fake junk or "seconds".

author: warnberg
author_rank: Contributor
timestamp: January 19, 2016, 03:51:29 pm
content: Thanks everyone... can never have enough resources for parts.Thanks AgainDave

author: Cliff Matthews
author_rank: Unknown
timestamp: January 19, 2016, 04:25:16 pm
content: Quote from: Audioguru on January 19, 2016, 03:49:32 pmI didn't know ebay stocked the final products..Due diligence can start with ongoing seller reputation lists eg:http://www.sciencetronics.com/greenphotons/?page_id=855and perhaps sending non-accusational question's like: "could your supplier be providing you with fake or knock-off (part number)'s?" and "what is your policy when one is found?". Not saying there's guarantee's, but for non-criticals, it's hard to match.

author: rdl
author_rank: Super Contributor
timestamp: January 19, 2016, 05:38:03 pm
content: The big three are Digi-key, Mouser, and Newark/E14. Just buy from whichever is closest to you (if price is similar) so that you get fast delivery times. One difference to be aware of is sales tax, I think Digi-Key and Newark collect it no matter what, but currently Mouser only charges it in a few states.

author: Thor-Arne
author_rank: Unknown
timestamp: January 19, 2016, 06:43:10 pm
content: And there isTayda Electronics.

author: bcbeck96
author_rank: Newbie
timestamp: January 19, 2016, 07:59:32 pm
content: Jameco has a much better easier website to use and the price is decent when purchasing in small quantities.

author: crispy_tofu
author_rank: Super Contributor
timestamp: January 19, 2016, 10:49:46 pm
content: Vaguely relevant:https://www.eevblog.com/forum/beginners/from-no-parts-to-decent-stockpile-best-approach/

author: TimFox
author_rank: Super Contributor
timestamp: January 20, 2016, 12:05:50 am
content: In the US, there is also Alliedhttp://www.alliedelec.comOn their website, look for "Excess Inventory" under "Resources" for good deals.
parts suppliers - Page 1
Forum section: electronics / beginners

author: krazy707
author_rank: Newbie
timestamp: July 15, 2020, 06:04:01 am
content: Hello everybody, as the way it's happening India has blocked imports from China, and in future restricted or higher customs would be charged, so I need to find part suppliers who are from other parts of Asia, is there a other website that sells electronic components for this purpose may be Taiwan or something. things like mosfets, dc dc converters, etc. The sites that would sell components from manufacturers other than china, as the origin is looked at the port of entry. not sure how much times extra I may have to pay due to this
Passing IEC Level 4 System Level ESD Testing - Page 1
Forum section: electronics / beginners

author: XtraLumens
author_rank: Newbie
timestamp: September 23, 2020, 02:34:46 am
content: From my understanding, there are two models used to asses ESD sensitivity: HBM (component level) and IEC (system level). ESD protection can be implemented via on-chip and off-chip design measures. Is it possible to pass IEC testing only relying only on on-chip ESD protection measures?

author: T3sl4co1l
author_rank: Super Contributor
timestamp: September 23, 2020, 09:08:22 am
content: What constitutes an off-chip design measure? Some circuits fundamentally will not function without a minimum degree of design, for example the use of ground planes. But ground planes afford some degree of ESD immunity.If you mean, simply not going out of your way to add ESD-specific components, there are certainly some circuits that can succeed that way. A fairly trivial case is simply using devices that offer high ESD ratings in the first place.Whether any particular circuit can? Well, that'll require a lot more information about it. And not just the circuit, but software running on it as well, if applicable.Tim

author: tszaboo
author_rank: Super Contributor
timestamp: September 23, 2020, 10:07:16 am
content: Maybe. You could pass it, but it depends on the IC in question. IE, an RS485 transceiver could have the necessary protection to pass it. A low input bias current opamp will probably not pass. It also depends on your layout, enclosure and other factors.

author: XtraLumens
author_rank: Newbie
timestamp: September 23, 2020, 08:39:11 pm
content: Thanks for the responses.From the literature I've been reading, on-chip protection measures usually are harden to HBM standards, whereas off-chip protection measures (e.g. transient diodes) are rated to IEC system level standards. It has been stated that the response time of a HBM protection circuit will not turn on in time if an IEC level discharge were to occur and possibly fry the sensitive IC. This is because the IEC waveform rise time is ~0.7- 1 ns, where as the HBM waveform rise time is around 25 ns. I really want to understand the mechanisms behind this.It seems that in order to ensure robust protection (especially to level 4), the use of off-chip protection measures may be necessary for system level ESD protection.
passive Bessel filter? - Page 1
Forum section: electronics / beginners

author: fonograph
author_rank: Frequent Contributor
timestamp: October 16, 2017, 04:29:10 pm
content: Is it possible to make passive 4th order bessel filter? I think I read somewhere that its impossible to make it from passive components,that it needd to be active filter in order to be bessel type,is that true?

author: chris_leyson
author_rank: Super Contributor
timestamp: October 16, 2017, 04:40:08 pm
content: You can make a 4th order passive Bessel filter without any problems, to say it can only be done with active filters is nonsense.You just have to find the right text book or the right software to design the filter. I think passive filter design is possable with Matlab or Octave which is free.

author: Kalvin
author_rank: Super Contributor
timestamp: October 16, 2017, 04:44:26 pm
content: Quote from: fonograph on October 16, 2017, 04:29:10 pmYes. False.

author: fonograph
author_rank: Frequent Contributor
timestamp: October 16, 2017, 04:50:40 pm
content: Thank you,both of you.Is there any filter type that can only be active?

author: Kalvin
author_rank: Super Contributor
timestamp: October 16, 2017, 04:54:28 pm
content: Ps. Here is a quick/short tutorial for designing passive filters using tables in a cookbook fashion:http://web.stanford.edu/class/ee133/handouts/labs/EE133filterCookbook.pdf

author: chris_leyson
author_rank: Super Contributor
timestamp: October 16, 2017, 05:03:02 pm
content: QuoteI can't think of any.

author: basinstreetdesign
author_rank: Frequent Contributor
timestamp: October 16, 2017, 07:28:30 pm
content: Quote from: fonograph on October 16, 2017, 04:50:40 pmIf you can classify a gyrator as a filter then there's that.4th order Bessel?Here's one pictured:

author: LvW
author_rank: Frequent Contributor
timestamp: October 17, 2017, 09:45:01 am
content: Quote from: fonograph on October 16, 2017, 04:50:40 pmYes - all filters based on integrators are active because (nearly ideal) integrators can be realized only on the basis of active (amplifying) blocks.Examples: KHN-Filter structure, Tow-Thomas.
Passive Component Values for SMPS With Variable Input Voltage - Page 1
Forum section: electronics / beginners

author: Frodo Muggins
author_rank: Newbie
timestamp: April 25, 2023, 02:39:16 pm
content: Hello everyone,I am new in forum. So, I am sorry if I made a mistake.My professor asked me to design a SEPIC converter with the following properties on Simulink;Vs = 12-36V,R = 5 ohm,Fs = 50kHz,Vout = 28V,Pout = 100W.Ripple variations of inductor currents' ripple are Io.5% for L2 and Iin.5% for L1 and output voltage riple is 0.5V.For inductor values, I found ;L2 = 0.24 uH and L1 = 0.1 uH for Vs = 12V; and,L2 = 0.57 uH and L1 = 0.57 uH for Vs = 36V.but the output voltage is not stable for Vs = 12V when the inductor values are according to 36V. And the same goes for vice versa (Vs = 36V & Inductor values are according to 12V)Also, I am facing the same problem with all DC-DC converters with an input voltage that defined in a range.What should I do to obtain stable output for Vs = 12-36V range?I am adding the Simulink schematic and my calculations.Thank you in advance.

author: Jim from Chicago
author_rank: Regular Contributor
timestamp: April 25, 2023, 07:20:51 pm
content: Have you tried splitting the difference and calculating values for Vs = 24V? Maybe that will give you an acceptable compromise.
passive in-rush current protection - Page 1
Forum section: electronics / beginners

author: raphrath
author_rank: Newbie
timestamp: August 03, 2020, 05:19:05 am
content: I am Working on a excercise to make a "useless" circuit that tells you when it's unplugged.The general idea was to have a supercap that turns on a LED when power is disconnected from a microUSB port. I am deleberatley over-engineering the daylights out of it (for practical excersise) and want to include a passive circuit (presumably in the red circle) to limit the inrush current when power is first connected. I was thinking it would involve an inductor but I also want it to be very compact ie not much larger than two microusb ports, so that may limit my options.I know roughly what each compionent does but Im not familular with the maths that goes with them so please dont do that for me.PS. yes I am using easyeda, yes I know its shit, no I cant be bothered installing something better ATM.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: August 03, 2020, 06:05:51 am
content: 1. Try a current source. The BJT and two diodes, or ring of two BJTs, or one BJT and bias resistors, are all fine options.2. You need a pull-down on +5V else the LED doesn't light.Tim

author: Berni
author_rank: Super Contributor
timestamp: August 03, 2020, 06:08:07 am
content: Firstly you need a pulldown resistor on the 5V rail otherwise the transistors base just ends up floating.Easiest inrush protection is simply a resistor. If you want something that acts like a more constant current source then a JFET or depletion MOSFET with 0V on its gate can be used. If you want to stick with BJTs then a PNP with a weak pulldown on its base can be used, so the transistors Hfe gain will multiply that small pulldown base current into a proportional larger current flowing trough the transistor. Its all far from an accurate consonant current but for just liming current its good enough.
Passive piezo buzzers - Page 1
Forum section: electronics / beginners

author: queennikki1972
author_rank: Regular Contributor
timestamp: May 07, 2019, 01:54:00 am
content: I accidentally ordered passive Piezo Buzzers instead of Active. I have about 15 of them and they do not work with most simple circuits calling for a piezo buzzer. What can i do with them . I know they require AC signal to work, but I am not far enough along to play with AC yet other than transformers in power supplies.

author: alank2
author_rank: Super Contributor
timestamp: May 07, 2019, 02:48:28 am
content: Are you playing around with microcontrollers? You can connect a passive piezo directly to most microcontroller pins and then toggle the pins at different frequencies to make sound. A trick to make it louder is to toggle both pins to the opposite polarity at the same time to make it louder. For example, pin1=output low, pin2=output high, and then immediately change it to pin1=output high, pin2=output low. Quieter could be leaving pin2 output low and then taking pin1 between output high and output low.

author: queennikki1972
author_rank: Regular Contributor
timestamp: May 07, 2019, 03:37:28 am
content: Thank you, Ill try that, hate to waste them.

author: Zero999
author_rank: Super Contributor
timestamp: May 07, 2019, 09:25:21 am
content: Do the buzzers have two or three leads?The three leaded variety are easier, as one transistor is all that's required.The inductor variant is louder, but more expensive.Otherwise there's the classic two BJT astable. D1 and D2 aren't needed if the supply voltage is below 6V.

author: queennikki1972
author_rank: Regular Contributor
timestamp: May 08, 2019, 06:31:25 am
content: They are 2 lead

author: Zero999
author_rank: Super Contributor
timestamp: May 08, 2019, 08:39:24 am
content: Quote from: queennikki1972 on May 08, 2019, 06:31:25 amAll you need is a square wave, equal to the frequency you want the piezo to buzz at.The previous circuit I posted, with the two BJTs will do that, but it isn't the easiest way. Here's another method using the 74HC14. It's possible to use only one or two Schmitt trigger elements, but they're six in the IC and it's more stable with four: one as the actual oscillator and another three to buffer the signal to drive the piezo. If you need to use a higher voltage, than 6V, then use the same circuit, but with the CD40106, which will work up to 18V.If you're using a microcontroller, you can just program it to output a squarewave and attach the piezo directly to the output pin. As mentioned above, using two pins, with the opposite polarities and connecting the piezo between them, will make it louder.
Password setting option in digital lock code using 8051? - Page 1
Forum section: electronics / beginners

author: shobit2
author_rank: Newbie
timestamp: February 11, 2016, 12:30:43 pm
content: I am building a Digital lock using AT89s52, I have seen some projects on web, I have used this one to build Digital lock:Digital code lock using 8051,Its working fine but in this project, password is predefined in code, but I want to set the password on run-time. Then I further searched and usedthis codein my project. But as soon as i used this code, it gives me error in the code. Later project is built on AT89c51, Is this problem? Can any body help.
Patch leads BNC - Page 1
Forum section: electronics / beginners

author: Deathwish
author_rank: Unknown
timestamp: July 10, 2015, 05:55:17 pm
content: I have always thought that you should only use 50ohm RG58 cable for leads from one piece of kit to another, but I keep seeing RG59 cable listed as patch leads in such places as RS, what would be the difference in the two from say a sig gen to a scope or other stuff.what is annoying me is that I can pick up a RG59 cable for about £1.50 but a similar one in RG58 is around £8.

author: Paul Moir
author_rank: Frequent Contributor
timestamp: July 10, 2015, 06:37:00 pm
content: Impedance mismatch. RG-59 is 75 ohms while test equipment is 50 ohms. RG-59 is for video, which is far more popular than radio / test equipment, so it costs less. (And I would argue that they're likely not using the best wire anyway.)Having an impedance mismatch will cause reflections and losses. Also note that while 75 ohm BNCs and 50 ohm BNCs look generally the same, they're a little different.EDIT: It's pretty popular to make your own BNC cables. It won't really save you money but you can make the lengths you need out of decent wire & connectors.

author: Deathwish
author_rank: Unknown
timestamp: July 10, 2015, 06:52:33 pm
content: I knew it was 75 ohm on the RG59 as I used to use it for satellite cable when i couldnt get my hands on FT100/125 stuff occasionaly. It just got to me that some places were trying to pass it of as patch leads for interconnecting other things and wandered what the problems would be.I used to make my own cables way back but not anymore having lost the crimper etc, and silly places like maplins want to charge as much for 1 metre of RG58 as a ready made cable for 1.65 on ebay so it really isnt cost effective anymore for me.

author: tggzzz
author_rank: Super Contributor
timestamp: July 10, 2015, 07:25:29 pm
content: Quote from: Deathwish on July 10, 2015, 05:55:17 pmUse 50ohm cable for 50ohm equipment. Use 75ohm cable for 75ohm equipment.If one end is 50ohm and the other 75ohm, put a 50/75ohm impedance matcher in the relevant place with the relevant orientation. A wideband passiveresistive50/70ohm matcher will lose ~6dB power. If you can't tolerate 6dB loss, then there are narrowband and active alternatives.Be very careful of inserting an Xohm cable into a Yohm socket; frequently the centre conductor and/or dielectric diameters are different, which might require "undue" force. usehttp://chemandy.com/calculators/matching-pi-attenuator-calculator.htmfor the resistor values, e.g. 45, 86, 2380 ohms. I've made one to connect a 75ohm SDR receiver to 50ohm systems.
Path of least resistance? - Page 1
Forum section: electronics / beginners

author: joblessalex
author_rank: Contributor
timestamp: September 07, 2013, 08:04:10 am
content: Simple quick question for the proffessors, if electricity takes the path of least resistance, how come current flows through two parralleled resistors instead of just the lowest one?

author: cyr
author_rank: Frequent Contributor
timestamp: September 07, 2013, 08:34:35 am
content: Because "takes the path of least resistance" is just an (over)simplification.It is approximately true if there is a very large difference in resistance.

author: BravoV
author_rank: Super Contributor
timestamp: September 07, 2013, 08:58:03 am
content: Imagine two pipes in paralel, one has huge diameter, say as big as a train, and another one as small as a straw, and both connected to the same water source.I don't think its intuitive to conclude that there must be NO water flow at all in the straw, "no" here means complete zero.

author: CalG
author_rank: Contributor
timestamp: September 07, 2013, 02:09:14 pm
content: The "IF" in your question is the flaw .Electricity DOES NOT FOLLOW THE PATH OF LEAST RESISTANCE. .................Clear that from your mind.Electricity flows through all resistances in inverse proportion to the resistance. (replace with impedance if desired)Other wise, voltage divider networks could never be calculated. (or any balanced circuit for that matter.)

author: joblessalex
author_rank: Contributor
timestamp: September 07, 2013, 02:41:02 pm
content: Whew. Thanks for clearing that up. I always used paralleled resistors and had no idea why they worked! That is a much more reasonable explanation.
Pawe supplye. - Page 1
Forum section: electronics / beginners

author: Edwin the inductor
author_rank: Newbie
timestamp: February 02, 2020, 05:20:03 pm
content: Any one that know where I can buy good and not to expensive bench pawer supply?

author: ArthurDent
author_rank: Super Contributor
timestamp: February 02, 2020, 05:41:09 pm
content: Not enough information to go on. What are you planning on powering? what is your budget? Please give enough information so posters can make informed recommendations.
PB137 Battery Charger - Page 1
Forum section: electronics / beginners

author: CBP
author_rank: Contributor
timestamp: July 09, 2016, 05:17:02 pm
content: Hi,I have built a STMicro PB137 based battery charger, the circuit is pretty much identical to the circuit in the datasheet (https://www.parallax.com/sites/default/files/downloads/601-00526-PB137-Datasheet.pdfon page 5) plus a fuse and a breakout for a fan to keep it cool (it is also sitting on a heatsink).I can't find a great deal of information about this IC on the net and it appears to do that job of charging the 7.5Ah SLA I have connected to it which is coming from a 24V 2.5A PSU. However I have no method of knowing when the battery is charged, my instinct tells me as the device is apparently clever then it will start to drop the current off as the battery reaches full capacity. I can't find anything in the datasheet that supports this or any charts concerning output current, basically at the minute it is charging at 600mA according to the ammeter I have in line with the battery (and it has been higher). Should I be of the impression that as it is around 50% of the maximum output current (1-1.5A) then the battery is around 50% charged or is this more complex than I am giving it credit for?Thanks..

author: mikerj
author_rank: Super Contributor
timestamp: July 11, 2016, 08:22:10 am
content: It's simply a constant voltage regulator, with over-current limiting. It's not doing anything clever at all, charge current will naturally be proportional to the difference between the regulator output (13.7v) and the battery voltage and either limited by the internal resistance of the battery or the regulator if current is over 2.2Amps.Charging is complete when the current has stabilised at it's lowest level, the exact current this occurs at will depend on your particular battery and ambient temperature.

author: hammy
author_rank: Unknown
timestamp: July 11, 2016, 09:28:30 pm
content: Quote from: CBP on July 09, 2016, 05:17:02 pmOn page 8 is a chart named "output voltage vs. output current".You need a big heatsink for a high output current.Cheershammy

author: usagi
author_rank: Frequent Contributor
timestamp: July 13, 2016, 11:02:19 pm
content: any reason you couldn't run multiple pb137 in parallel for higher current capacity?

author: hammy
author_rank: Unknown
timestamp: July 14, 2016, 02:41:08 pm
content: I never tried it, but it looks like that this ispossible.

author: usagi
author_rank: Frequent Contributor
timestamp: July 21, 2016, 12:35:26 am
content: Quote from: hammy on July 14, 2016, 02:41:08 pmany idea what R2 and R3 are for?

author: mikerj
author_rank: Super Contributor
timestamp: July 21, 2016, 07:54:31 am
content: Quote from: usagi on July 21, 2016, 12:35:26 amThey help ensure the charging current is more equally split between the two regulators. Without these, any small variations in the regulators output voltage (and they all have some tolerance of course) will mean one regulator might carry most of the current.
PB507LAB eventually arrived ready for me and my son to learn together - Page 1
Forum section: electronics / beginners

author: xpr2_2
author_rank: Newbie
timestamp: December 18, 2024, 05:17:37 pm
content: so i bit the bullet and purchased this newer bit of kit ( i have afew of the older versions), it wasn't cheap it has all the courseware with it which will be super exciting to work through with my son through the holidays. the biggest issue was getting the software to work as it doesn't work on win10 or 11 even though it claims it does. the drivers do not work unless its a winXP, saying that it probably would work if i really looked into it, since i have a bunch of old junk laptops with winXP on them i figured what the hell, so i booted up installed service pack3 some ms framework client software, and hay prestro got it to work. the software can control all aspects of the device which is quite cool i pulled up the portable scope to check the signals comes out of the function generator and there super clean and go up to 1mhz! which is pretty surprising.anyway pic included for your enjoyment!
PC 18f2550 timer0 problem - Page 1
Forum section: electronics / beginners

author: khatus
author_rank: Regular Contributor
timestamp: June 23, 2019, 05:48:09 am
content: https://www.electronicwings.com/pic/pic18f4550-timer-capture/*Frequency Measurement using Input Capture Mode in PIC18F4550http://www.electronicwings.com*/#include <stdio.h>#include <stdlib.h>#include <p18f4550.h>#include "osc_config.h"#include "LCD_8bit_file.h"#include <string.h>#define f_timer 2000000void main(){unsigned long signal_period,data1,data2;unsigned long frequency_Hz;float Frequency;TRISCbits.TRISC2=1;OSCCON=0x72; /* set internal clock to 8MHz */LCD_Init();memset(frequency_Hz,0,20);LCD_String_xy(0,1,"Pulse");PIE1bits.CCP1IE=1;PIR1bits.CCP1IF=0;CCP1CON=0x05; /* Capture mode is selected for detecting Rising edge */CCPR1=0x00; /*CCPR1 is capture count Register which is cleared initially*/TMR1IF=0;T1CON=0x80; /* Enable 16-bit TMR1 Register,No pre-scale,use internal clock,Timer OFF */TMR1=0;TMR1ON=1; /* Turn-On Timer1 */while(1){while(!(PIR1bits.CCP1IF)); /*Wait for Interrupt flag which is generated when edge is detected*/PIR1bits.CCP1IF=0;data1 = CCPR1; /*Copy count of 1st edge detected*/while(!(PIR1bits.CCP1IF)); /*Wait for Interrupt flag which is generated when edge is detected*/PIR1bits.CCP1IF=0;data2 = CCPR1; /*Copy count of 2nd edge detected*/if(data1 < data2){/*Calculation for Frequency Measurement*/signal_period = data2 - data1;Frequency = ((float)f_timer / (float)signal_period); /*Count for 1 cycle*0.5us gives period */sprintf(frequency_Hz,"%.3f ",Frequency);LCD_String_xy(2,0,frequency_Hz);}TMR1=0;memset(frequency_Hz,0,20);}}this is the code which measure Frequency of the input signal and display it on 16x2 LCD. I want to convert this code from mplab to mikroc .But i mikroc when i declareTMR1=0;it shows error.How i can overcome this problem??

author: ggchab
author_rank: Frequent Contributor
timestamp: June 23, 2019, 08:13:57 am
content: And check the doc: TMRxH might have to be initialized before TMRxLThe high value is stored in a temporary register and really loaded in TMRxH when TMRxL is written.

author: MarkF
author_rank: Super Contributor
timestamp: June 23, 2019, 02:11:24 pm
content: And please use the code tag "#" button while editing in the future.It places the code in a small frame using a mono spaced font.
PC CPU/Display update noise on audio amplifier. - Page 1
Forum section: electronics / beginners

author: paulca
author_rank: Super Contributor
timestamp: November 04, 2017, 09:00:55 am
content: I've read a few things about this on PC forums, but solutions are wide ranging, sometimes expensive and generally non-conclusive, so I thought the wealth of RF knowledge in here might shed light.I have a small digital headphone amp. Annoyingly Windows only supports a single output, so I have to switch it between Digital Headphone amp and analogue (soundcard output) and remember to do so before I launch a game or I have to restart it.The digital amp has a pass through (completely passive/electrical), so I wired it up to the sound card and now I can have both. However it's analogue mode and .... it's NOISY. The amount of RF noise from the PC would actually make you feel sick at high volumes. You can hear the mouse move, the webpage scroll, etc. etc.There is debate as to whether this is coming from the video card, the monitors or the PC Mobo/CPU. I'm thinking the video card as it seems more display update related than pure CPU.The RCA cables in use are not the cheapest, but there certainly are not brand name and I doubt they are properly shielded.So far my options seem to be:1. Split the cables open and ferrite ring the shield/ground line.2. Buy expensive Mu shielded RCA cables.3. Buy some potentially snake oil box to filter the audio - I'm particularly concerned with filtering as the noise is audible range, so a filter will also filter the sound itself which would bother me.Note: when the h/phone amp is running in digital mode there is still some noise, but it's barely perceptible and must be getting in through the heavy metal case and into the analogue side of the pre-amp. I'm not really concerned about this, as you have to listen for it at high output settings or you just don't notice.

author: Ing. Max Koschuh
author_rank: Newbie
timestamp: November 04, 2017, 09:42:24 am
content: My computer used to add HUGE noises to the audio signal, which was VERY annoying. Exactly as you described it. High pitch noise when scrolling, scattered noise when moving the mouse, etc...I tracked it down to the SSD, producing RF interference like a boss.The solution turned out to be very simple and cost effective:All I did was adding (*clip-on) ferrite beads to any of the cables inside and outside my computer. This is a free solution, if you have kept all the ferrites from torn down equipment.Add ferrites to each and every power cable (+5V/+12V), main board power cable, graphics card PSU cable, signal cables (IDE, SATA). Outside: The power cord of BOTH the computer and your stereo, USB cables, ethernet cables, HDMI cables....*and onto the RCA cables aswellMy computer is now absolutely silent, in terms of noise in the audio output.
Pc power supply for electrolysis  - Page 1
Forum section: electronics / beginners

author: krhoover
author_rank: Newbie
timestamp: October 01, 2023, 09:16:32 pm
content: The attachments show the power supply and how I have connected wires. It starts up on bench and I get 12 volts. When I hook it up to the electrolysis tank it won’t run. With a battery charger my meter on it is pegged at 8 amps. I run the charger on 6 volts and it reads about 4 amps. Maybe it’s just too much for the power supply? Maybe I have the wires connected wrong, or the electrolyte too strong. Any advice appreciated.Thanks

author: Hiemal
author_rank: Regular Contributor
timestamp: October 01, 2023, 10:39:36 pm
content: Can you tell if the power supply is clicking/hiccuping? It might be hitting its current limit, and is skipping cycles to protect itself. Would be my first guess.

author: krhoover
author_rank: Newbie
timestamp: October 02, 2023, 12:24:07 am
content: That was my thought. Am I correct that it should handle 12 amps max at 12 volts.

author: Shonky
author_rank: Frequent Contributor
timestamp: October 02, 2023, 12:53:14 am
content: You may have issues pulling a large load on +12V with no load on +5V and/or +3.3V

author: krhoover
author_rank: Newbie
timestamp: October 02, 2023, 11:24:46 am
content: I have read that on some sites about putting a resistor of som sort on the 5 volt wires. Any recommendations as to what?

author: u666sa
author_rank: Frequent Contributor
timestamp: October 02, 2023, 12:19:25 pm
content: You have to pay close attention to POWER_GOOD signal and you have to load 5 volt rail with 10 ohm resistor, about 5 watts. These are usual conditions for PWM chip to start power supply. Now, these power supplies are designed for 5V and 3V rails, 12V is there, but it is not the most powerful. There are guides out there on how to convert your power supply to 12 volt, that way you get full power on 12 volt rail.You should be able to run it. If it is something you doing only once this power supply is okay. If you doing things professionally on repeat basis, purchase a lab power supply. For example Owon SPE6103 or SPE3103. (Be sure to not over pay for them, about $80 for 30 volt 300 watt version is proper price)Also, check out coppering --You basically make a solution with just 3 ingredients, and stick your degreased metal part into it, out comes a part with a nice copper coating, no electrolysis needed. Uses are many, for example copper plating your microscope stand so it's copper looking instead of standard chrome, making your old bathroom facet look new again, etc.There is another technique with electrolysis, zinc plating rust right on your vehicle body. Removes and stops rust, goes right under paint. A lot cheaper than prepping and repainting entire body panel.
PC PSU Bench Power Supply - Page 1
Forum section: electronics / beginners

author: aidan2496
author_rank: Contributor
timestamp: April 16, 2015, 11:06:04 am
content: Hi guys!I'm planning on making a bench power supply from a computer psu which i'm yet to buy! I understand there high amp supplys but would that effect an ledif i just attached it strait to the 3.3v socket or do i need to do something?Thanks,Aidan

author: Simon
author_rank: Unknown
timestamp: April 16, 2015, 11:10:12 am
content: ok two misconceptions here:1) that you can have "too many" amps from a supply, never the case, too many volts yes does damage, but your circuit will only use the amps it needs even if more are available.2) that you just apply voltage to an LED to make it work. LED's have a varying voltage from 1.8V to 3.8V, they are diodes which means they don't try to restrict current and will allow as much through as possible until they blow. You need a resistor in series with the LED. If just an indicator then 10mA will do so (3.3V-LED V)/0.01

author: aidan2496
author_rank: Contributor
timestamp: April 16, 2015, 11:13:54 am
content: Quote from: Simon on April 16, 2015, 11:10:12 amThanks! Great help!

author: jeroen79
author_rank: Frequent Contributor
timestamp: April 16, 2015, 11:08:44 pm
content: 3) An ATX PSU's protection features will not care about your circuit in any way.If the PSU is rated at 20A on a rail and you make a mistake that causes your circuit to draw 20A then the PSU will happily oblige, even if this current will destroy your circuit.So be careful.

author: RoboTechEd
author_rank: Regular Contributor
timestamp: April 17, 2015, 03:43:16 am
content: Also some computer PSUs won't actually output properly unless there is a big enough load attached to them. It may be a good idea to use something to pull the voltage down to where it is expected

author: Fermín
author_rank: Newbie
timestamp: April 17, 2015, 12:21:38 pm
content: I think you should try to make your own bench power supply with current control, wich comes really handy and is easy to build. there are lots of schematics online. I recommend you to watch Mjlorton's series about that.https://www.eevblog.com/forum/beginners/diy-bench-power-supply/
PC PSU in series with no minimum load - Page 1
Forum section: electronics / beginners

author: MeliorMundus
author_rank: Newbie
timestamp: March 12, 2022, 06:48:49 pm
content: Greetings!Need a little help regardless PSU-s.So i got myself four PSUs from some HP servers. They are all ATX and they all have same specs, but two of them cant start without load.I need to put them in series so i could get 48v for another project.Unfortunatley, they don't have seperate ground on 12 5 and 3.3 V, and can't put any load if i put them in 12V series.I searched over internet, but there is no info on this specific issue, that I can find.I alleready isolated PCBs from case and connected grounds spots on PCB with wires, and put diodes across 12V before putting them in series.Any idea how to start them and not blow them? THX in advance

author: madires
author_rank: Super Contributor
timestamp: March 12, 2022, 07:21:47 pm
content: Welcome to the forum! Better get a 48V PSU (look for telco surplus). No headaches with different start-up times, EMI, and other issues when putting multiple SMPSUs in series.

author: MeliorMundus
author_rank: Newbie
timestamp: March 12, 2022, 07:28:05 pm
content: THX madires, but not an option for tonights build

author: MeliorMundus
author_rank: Newbie
timestamp: March 12, 2022, 07:31:20 pm
content: Can i put some load between 5 and 3.3V positives to fool it to work? I checked, 12V from the fan is different ground. Can i put something betweeen 5v and fan GND?

author: Gyro
author_rank: Super Contributor
timestamp: March 12, 2022, 07:31:52 pm
content: ATX PSU outputs are all ground referenced aren't they? I don't think youcanput them in series.I might be wrong of course.

author: MeliorMundus
author_rank: Newbie
timestamp: March 12, 2022, 07:49:36 pm
content: i isolated PCB ground from earth.

author: Gyro
author_rank: Super Contributor
timestamp: March 12, 2022, 07:52:16 pm
content: Ah, ok. Definitely not recommended safety wise, but I understand.
PC sound card oscilloscope - Page 1
Forum section: electronics / beginners

author: Leuven
author_rank: Regular Contributor
timestamp: October 27, 2011, 01:35:01 am
content: I am trying to put together a MAC based oscilloscope for one purpose only: to detect maximum signal level before clipping in car audio components (headunit, processors, amplifiers etc.), and ONLY working with 3 test tones - 40Hz, 1KHz and 4KHz.So far I have acquired the software (Electroacoustic toolbox) with a suitable oscilloscope function and I have an external M-Audio Firewire Solo sound card with a max. unbalanced input of 1.3Vrms and 150?Ohm line in impedance. As probes I am using some 18AWG wire with a mono 1/4 jack at the sound card's end and croc clips/RCA plug at the other. Knowing that I will routinely work with voltages higher than 1.3, the lead goes through a project box with a 1kohm variable resistor used as a voltage divider. That helps to tune down the voltage to 1V no matter what goes in.In a very basic way, it actually works - or at least it appears to work. I get correct sine waves representation, clipping is shown pretty much where I expect it to show - including sound card clipping if I leave the voltage go past 1.5V on the line in.What am I expecting from this thing in terms of accuracy compared to an old school analog scope for example? Also any general advice of what to watch for?Thank you in advance,Adrian

author: jahonen
author_rank: Super Contributor
timestamp: October 27, 2011, 09:53:54 am
content: I suggest you build a front-end which protects the sound card from blowing up (I have seen some project but can't remember the URL), in event if you inadvertently connect it to something nasty, something like 100 volts DC. Or if channels have common ground (no balanced input), then a differential amplifier which again prevents magic smoke escaping if you connect it to speaker output which is bridged (common stuff in car amplifiers). Same happens if you connect to two non-bridged amplifier outputs and put the other channel with leads reversed.At low frequencies, the sound card has better dynamic range and lower distortion figures than normal oscilloscope, but DC measurements are not usually possible, and even they could be done with modifications, the stability and accuracy might not be very good (naturally, DC accuracy is not required in audio applications).Regards,Janne

author: Leuven
author_rank: Regular Contributor
timestamp: October 27, 2011, 12:44:12 pm
content: Thanks Janne, I've got a rms multimeter plugged into the project box at all times so I will be monitoring any voltage very closely before it gets into the sound card. So I take it it's good as long as I'm being careful.I looked over a few diagrams for front end protection but they were above my head to be perfectly honest.

author: johnmx
author_rank: Frequent Contributor
timestamp: November 03, 2011, 10:38:45 pm
content: Check out this article: “Front End Turns PC Sound Card into High-Speed Sampling Oscilloscope”http://www.analog.com/library/analogdialogue/archives/45-11/soundcard.pdf
PC1602-h i chowdered the ground pin. - Page 1
Forum section: electronics / beginners

author: ionicwake
author_rank: Newbie
timestamp: March 31, 2017, 07:05:45 am
content: so, as you can see by the pictures, i chowdered this thing but good while trying to solder a wire to the ground pin. now i have looked up the pinout and i have tried to solder to the ground plane in hopes of resurrecting this poor thing to no avail. is there anywhere else i could attempt feeding power through? I would rather use this thing then having it hit a landfill.http://i653.photobucket.com/albums/uu252/ionicwake/20170331_001803.jpgthanks!Ion

author: bktemp
author_rank: Super Contributor
timestamp: March 31, 2017, 09:15:32 am
content: You could try the golden pads the metal frame is connected to. Since they are connected to traces there is probably a solerable jumper somewhere for shorting them to GND.Maybe R8 or R9 or J5.
pcb - Page 1
Forum section: electronics / beginners

author: noah_fakelastnamelike_bob
author_rank: Regular Contributor
timestamp: March 15, 2014, 08:22:58 pm
content: what places could i get this made or should i just make it and find a way fit it all together than use a pcb. in Missourihttp://www.josepino.com/audio/mini_amplifier_lm386iam using the x20

author: apelly
author_rank: Unknown
timestamp: March 15, 2014, 08:31:37 pm
content: Excellent thread:https://www.eevblog.com/forum/manufacture/can-anyone-recommend-a-cheap-easy-to-deal-with-pcb-manufacturer/Excellent link from that thread, with ball-park pricing:http://digital-diy.com/general-electronics/321-pcb-fabrication-sources.htmlFrom asking around here recently, the three main ones (for cheap, small prototypes) are (in no particular order) itead, seeed and elecrow.

author: noah_fakelastnamelike_bob
author_rank: Regular Contributor
timestamp: March 15, 2014, 08:33:33 pm
content: thank you

author: electronics man
author_rank: Frequent Contributor
timestamp: March 15, 2014, 08:46:12 pm
content: Just remember pcb pool are good, they have there own free cad software and dave seemed to like them in a video he did.