hybridfree/eevblog-posts huggingface dataset:
How to identify part for replacement? - Page 1
Forum section: electronics / beginners

author: Greorge
author_rank: Regular Contributor
timestamp: February 10, 2014, 02:47:21 am
content: Became proud owner of a discarded, what is supposed to be blown Step Down Buck converter(Hope got the name right)Main component is blown (part of name is missing), how can I identify what it is, to get replacement on E-BayI know that they are inexpensive to get, as I saw cheapest one under $3 Australian, but for the sake of getting component and soldering it on, for me at least it would be nice challenge.Can somebody identify the part for me?Or is there something close enough to work with this crippled device?Many thanks for any help

author: Monkeh
author_rank: Super Contributor
timestamp: February 10, 2014, 02:55:31 am
content: It's an LM2596S-ADJ. Supposedly.If you buy one on eBay you'll end up with one as fake as the blown one.

author: Greorge
author_rank: Regular Contributor
timestamp: February 10, 2014, 02:59:31 am
content: Thanks for reply.Just spotted on the little board: SY-DC3003(assume this is step down from 30V to 3V at up to say 1 A to be on a safe side)Typed it in and got exactly looking gadget, wow that was easy (onc you know what to look for)http://www.goodluckbuy.com/mini-dc-dc-adjustable-voltage-stablizer-switch-power-supply-.htmlMini DC-DC Adjustable Voltage Stablizer Switch Power SupplyToo quick to post (should read first)Gadget is in voltage 3 - 30 Vout voltage is 1.2 to 18 Vand power 2AQuote

author: Greorge
author_rank: Regular Contributor
timestamp: February 10, 2014, 03:17:56 am
content: http://www.goodluckbuy.com/mini-dc-dc-adjustable-voltage-stablizer-switch-power-supply-.htmlMini DC-DC Adjustable Voltage Stablizer Switch Power SupplyTheir picture gives identical gadgetWill have to check if JayCar have them, but quick search with part number doesn't come back with part in stock.

author: Unknown
author_rank: Unknown
timestamp: February 10, 2014, 12:30:35 pm
content: Goodluckbuy.com?At least it's truth in advertising, I guess...If you're after the IC then forget Jaycar; try a real supplier (Element14/RS/Mouser/etc).

author: InventorGrissom
author_rank: Newbie
timestamp: February 25, 2016, 10:58:23 pm
content: George, I use the SY-DC3003 as an upgrade replacement for the original voltage regulator on my 1977 Cougar XR7 instrument panel as it is far more accurate.Monkeh is right, the chip is aLM2596S-ADJ.Sorry about 120 day delay but just now found this site.

author: dadler
author_rank: Unknown
timestamp: February 26, 2016, 08:03:27 am
content: Quote from: InventorGrissom on February 25, 2016, 10:58:23 pmGive or take 2 years
How to identify small IC's - Page 1
Forum section: electronics / beginners

author: Joseph_PDX
author_rank: Newbie
timestamp: September 30, 2019, 12:18:03 am
content: Hello,I am trying to identify a small IC, MSOP package I believe. It has an Analog Devices logo, 10 pins, is approximately 3mm square. The only other markings are D and 7S on another row.I think it is a 12 bit DAC based on my research into galvanometer driver circuits, but would like to be sure WHICH Analog Devices 12 bit DAC.The IC is in a circuit for a SLA printer that controls the galvo mirrors for positioning of the laser beam. It is immediately upstream of a UTC TL084 quad OpAmp. The CPU on the board is not functional but everything else seems to be working when I probe voltages and such so I wanted to try and tap into the circuit to see if I can make it function.I would very much like to know how to look up IC's when they have little to no markings on them. I tried google for a while but I have not yet found anything to help guide me to identifying a chip like this.Thank you-Joseph

author: Nerull
author_rank: Frequent Contributor
timestamp: September 30, 2019, 12:20:40 am
content: AD5663RBRMZhttps://www.analog.com/media/en/technical-documentation/data-sheets/AD5623R_43R_63R.pdf'D7S' marking on last page.First datasheet result on google for 'Analog Devices D7S'
how to identify smd dual capacitor - Page 1
Forum section: electronics / beginners

author: SILORAK
author_rank: Newbie
timestamp: February 02, 2018, 06:09:22 pm
content: Hi all. I am as green as it goes so sorry in advance. I have this part that I so far identified as an dual transistor but I am not sure. I would like to ask you if someone could identify the value of it or at least is it rely what I think it is. It is from clarion cdc4-00 (model pu-2590a) on some kind molex connector and its designation is fil203. So far I have searched google for four days for any documentations on that model of changer or connector and came out flat I will try to attach photo of the part but given as it is my first aptempt posting at any kind of forums it will probably go awry

author: phil from seattle
author_rank: Super Contributor
timestamp: February 02, 2018, 06:53:27 pm
content: capacitor? transistor? Hard to say but it looks like some sort of largish surface mount passive device. Fil == Filter? I'd guess capacitor just looking at it but maybe a ferrite bead. It's not clear are more than just 2 contacts. Seems like everything but the transistor is labeled filxxx. What is the blue device on the far side of the PCB? a connector?

author: SILORAK
author_rank: Newbie
timestamp: February 02, 2018, 07:32:57 pm
content: Yes, the blue device is a 12 pin connector, and a blown out component definitely had 3 pins.

author: chrisl
author_rank: Regular Contributor
timestamp: February 02, 2018, 09:04:52 pm
content: It is an EMI filter. Something like this:http://search.murata.co.jp/Ceramy/image/img/A01X/G101/ENG/NFM21HC224R1A3-01.pdfMeasure the dimension and look for a replacement.Cheers,

author: SILORAK
author_rank: Newbie
timestamp: February 03, 2018, 09:12:31 am
content: Thanks
How to identify / test a SMD TCXO crystal oscillator? - Page 1
Forum section: electronics / beginners

author: ON1DQD
author_rank: Newbie
timestamp: November 08, 2015, 01:53:04 am
content: Hi,I have some smd tcxo lying here and I don't now what they are, it has this description on it:LLG822T GD8525I can not find any datasheet nor can I get it to oscillate so I can measure it's output frequency.Does someone can help me to identify and help me on rail how to get it to oscillate, I nave have worked before with these small parts before.I hooked it up as the diagram attached.Thanks in advance!

author: ON1DQD
author_rank: Newbie
timestamp: November 18, 2015, 02:17:16 am
content: Thanks go to all the folks for the help (replies)I have got it running.This TCXO has a 28.800 MHz output.If someone is interested in the datasheet, PM me.

author: kcbrown
author_rank: Frequent Contributor
timestamp: November 20, 2015, 07:28:05 am
content: It might be helpful to the community if you posted what you had to do in order to get it working.
how to implement rotary encoder without microcontroller ? - Page 1
Forum section: electronics / beginners

author: IamSynthetiC
author_rank: Regular Contributor
timestamp: October 30, 2020, 09:03:45 pm
content: Greetings,I am trying to build a Nixie Tube kitchen timer with only "retro" components and style (logic ics only, no microcontroller). I want to use a rotary encoder to increment through the numbers but i can not think how to read the direction the switch is spinning ? Any ideas ?Thanks in advance.*i attach below a picture of the schematic (not at all finished), to give an idea of what is happening.

author: dl6lr
author_rank: Frequent Contributor
timestamp: October 30, 2020, 09:22:06 pm
content: If you have a rotary switch with a high resolution, you could use just a D-FF. Connect A to D und B to Clk of the FF. Q is then the direction and B is the CLK output. But you get a clock every 4 ticks only.Search for quadrature decoder will give you some results. You can either have direction and clock, or count up/down signals.Some details are available athttps://www.elektrik-trick.de/sminterf.htm(german, use google to translate) orhttp://basicelectronic.blogspot.com/2006/08/rotary-encoder-converter-circuit.html

author: Ian.M
author_rank: Super Contributor
timestamp: October 30, 2020, 09:30:05 pm
content: https://www.eevblog.com/forum/projects/quadrature-rotary-encoder/
how to improve PCB design - Page 1
Forum section: electronics / beginners

author: Aztlanpz
author_rank: Regular Contributor
timestamp: January 24, 2018, 02:23:10 am
content: What is the best way to improve PCB design.Aztlan

author: hsn93
author_rank: Regular Contributor
timestamp: January 24, 2018, 05:13:03 am
content: here are some resourceshttp://www.downstreamtech.com/downloads/UnderstandingDFM.pdfhttp://statics3.seeedstudio.com/fusion/ebook/PCB%20DFM%20V1.1.pdfhttps://resources.altium.com/design-for-manufacturing-dfm

author: ebastler
author_rank: Super Contributor
timestamp: January 24, 2018, 10:45:27 am
content: For beginners, the classic tutorial by our esteemed host is still a good starting point, I think:http://www.alternatezone.com/electronics/files/PCBDesignTutorialRevA.pdf

author: phil from seattle
author_rank: Super Contributor
timestamp: January 24, 2018, 05:51:19 pm
content: Kind of a wide open question. Where do you feel your designs are lacking? What kind of electronics are you doing?

author: Aztlanpz
author_rank: Regular Contributor
timestamp: January 24, 2018, 07:44:07 pm
content: I am mostly doing microprocessors design.Aztlan

author: ebastler
author_rank: Super Contributor
timestamp: January 24, 2018, 07:59:41 pm
content: QuoteQuote from: Aztlanpz on January 24, 2018, 07:44:07 pmPhil had actually asked two questions. Could you answer the first one too? Maybe in more than one sentence? You are not giving us a whole lot to go on...

author: phil from seattle
author_rank: Super Contributor
timestamp: January 24, 2018, 09:01:25 pm
content: Given the brevity and content lack in the question, Aztlan, I am guessing you a beginner. Here's a course of action:- read the links from hsn and ebastler.- read the forums.- look at PCBs others have done and try to understand the reasoning behind the design.- ask specific questions about things you don't understand- and, most importantly, practice. do lots of lay out. get familiar with the tools.I'd guess it will take around 100 hours to get comfortable with designing simple boards. Maybe 500 to be proficient and 10000 to be a deep expert (or so says malcom gladwell). Good luck.

author: AllTheGearNoIdea
author_rank: Unknown
timestamp: January 24, 2018, 09:50:34 pm
content: The best way and I think only way is to jump right on in there and design PCBs as many as you can. It’s an art as much as a science.

author: Dubbie
author_rank: Unknown
timestamp: January 24, 2018, 10:09:47 pm
content: I did an online course with Robert Feranec who has a company called Fedevel Academy.I really learnt a lot and feel that it was excellent value.I did the advanced hardware design one which cost $99It is geared towards Altium however. I use CircuitStudio which is 95% the same as far as the course goes.If you use another app, you may still get a lot out of it as it teaches mainly generic concepts that could be applied to other apps.R
how to improve the mc34063 to give more current? - Page 1
Forum section: electronics / beginners

author: little_carlos
author_rank: Regular Contributor
timestamp: August 21, 2015, 01:16:07 am
content: hey, i have this chip and im trying to make a 4 to 24 V variable power supply, but i want it to be up to 5 amps, how can i achieve this? can i add a mosfet or some mosfets to make it able to give that amount of current or what should i do? im working on this chip since its very cheap, so please dont tell me to go for other chip

author: alsetalokin4017
author_rank: Super Contributor
timestamp: August 21, 2015, 02:26:05 am
content: Well, I'd like to make an apple pie, but all I have is onions, how can I achieve this? Please don't tell me to use some other fruit, because onions are very cheap.(just kidding....)Did you try googling "variable power supply mc34063" and then looking at the Images? I see hundreds of different circuits using the MC34063 chip there.Thanks for your question, I've got a stock of 10 or so of the MC34063 chips myself, waiting for some interesting project to come along, and I see a few in the Google search that I might like to build.

author: free_electron
author_rank: Super Contributor
timestamp: August 21, 2015, 02:58:20 am
content: put a big fat short across the chip. all the current you want. and it'll work better than that stinking pile of silicon

author: kizzap
author_rank: Unknown
timestamp: August 21, 2015, 05:39:49 am
content: Quote from: free_electron on August 21, 2015, 02:58:20 amWhile i agree with the the statement, it probably isnt the most helpful in the *beginners* section.OP: consider looking into some of the more up to date switchers. LM2596 or something similar in that simple switchers might be able to help. You might need to go digging through datasheets.As a concern, you realize that you will require a supply transformer able to feed 150W at the highest output voltage+overhead?

author: MagicSmoker
author_rank: Super Contributor
timestamp: August 21, 2015, 10:33:36 am
content: It seems every EE likes to trash talk the MC34063 but it's been in continuous production by multiple manufacturers since the 80's so it can't be all that bad. That said, it's only really compelling advantage is that it doesn't need frequency compensation (because it uses hysteretic, or "bang-bang", control); this is even more of an advantage when the output voltage is variable.However, it isn't a very good choice if high efficiency and/or high output current are needed, and any modifications done to get around these limitations will both be ugly kludges and much more complicated than using a more modern switcher IC. If you want something that is cheap, also uses hysteretic control and which works reasonably well at 5A (theoretically to 8A) then take a look at the XL4016 by Chinese IC manufacturer XLSEMI:www.xlsemi.com/datasheet/XL4016%20datasheet.pdf
How to include leakage inductance in LTspice?  - Page 1
Forum section: electronics / beginners

author: Patrick66
author_rank: Regular Contributor
timestamp: January 07, 2024, 04:35:12 pm
content: Hello everyone, I would like to ask how do we include leakage inductance in LTspice? Do I need to change the coupling factor K. For my cause my Lpri is 1.84mH and Lsec is 0.235mH and my leakage inductance is 36.8uH. If possible can someone show me how to do it with example. Thank you for your time and consideration.

author: langwadt
author_rank: Super Contributor
timestamp: January 07, 2024, 05:12:58 pm
content: https://www.analog.com/en/technical-articles/using-transformers-in-ltspice-switcher-cadiii.html

author: liaifat85
author_rank: Regular Contributor
timestamp: January 07, 2024, 08:18:13 pm
content: You have already found your answer above. For some more details, you can see these too:https://groups.io/g/LTspice/topic/75412653?p=Created,,,20,2,0,0https://www.analog.com/en/technical-articles/ltspice-basic-steps-for-simulating-transformers.html
How to increase the starting voltage slowly in steps - Page 1
Forum section: electronics / beginners

author: ajoseph88
author_rank: Contributor
timestamp: September 21, 2015, 08:02:36 pm
content: At start, how to increase the starting voltage slowly... The starting voltage is 5V, and it is used to control the speed of dc motor, so at start the motor should start smoothly, increasing speed gradually... to limit the starting current... So I need to increase this control voltage 0 to 5V gradually at start.I tried to make use of RC charging time constant, it works, but I need it only during start... if it remains through out the operation, then the speed response is very slow... because of capacitor charging and discharging...The 5V is given to the microcontroller, which changes the ADC, which controls the speed of the motor...Any help, much appreciated...

author: Psi
author_rank: Super Contributor
timestamp: September 21, 2015, 08:08:16 pm
content: Soft motor start is the term your looking forIt's a a motor controller feature

author: jitter
author_rank: Frequent Contributor
timestamp: September 21, 2015, 08:17:23 pm
content: Quote from: ajoseph88 on September 21, 2015, 08:02:36 pmCan you bypass the RC network with (e.g.) a relay after the motor has spun to full speed?

author: IanB
author_rank: Super Contributor
timestamp: September 21, 2015, 08:21:14 pm
content: Can you do it digitally inside the microcontroller? When the controller receives an "on" signal it can gradually ramp up the PWM to the required value. When it receives speed control inputs it can pass them straight through without filtering them.

author: ajoseph88
author_rank: Contributor
timestamp: September 21, 2015, 09:00:09 pm
content: Quote from: jitter on September 21, 2015, 08:17:23 pmIt makes sense, i'll try...

author: ajoseph88
author_rank: Contributor
timestamp: September 21, 2015, 09:02:59 pm
content: Quote from: IanB on September 21, 2015, 08:21:14 pmI tried that, but if I try to modify or do anything with the ADC value or firing delay value inside the program, the value gets messed up... I'll still keep trying different ways to do this by program...
how to increase the voltage - Page 1
Forum section: electronics / beginners

author: mtc2629
author_rank: Contributor
timestamp: November 10, 2013, 08:05:57 am
content: Hi everybody i was just wondering how to increase the voltage of a signal.Like 1v to 30v but the same signal the problem is i dont want to blow up any components or really thin wire but i still want the same out put. For example if it gave out a high,low,low,high,low then a high i want it to be the same but a higher voltageThanksim making a remote control movable stand from a micro r/c helicopter

author: clockbiscuit
author_rank: Contributor
timestamp: November 10, 2013, 10:25:52 am
content: So you are looking for a DC-to-DC power supply? one way of doing this is known as a boost convertersee:http://en.wikipedia.org/wiki/Boost_converterHowever, this might not be the best answer to your question. Could you provide any additional information?Do you only have a single power source?What is the load?How much power is required and how much is available? (power = volts x amps)

author: Jon86
author_rank: Frequent Contributor
timestamp: November 10, 2013, 10:36:54 am
content: What is this signal coming out of? And do you already have this 30v available somewhere else in the system that you can use?If I understand right, you want to be able to increase the amplitude of a signal from some kind of IC, and you already have the higher voltage available, therefore you can use almost any transistor or MOSFET, or even a relay if your signal is slow.Can you tell us more about the system?
How to increment a binary counter by 8 each tick? - Page 1
Forum section: electronics / beginners

author: MarkS
author_rank: Unknown
timestamp: February 02, 2025, 09:34:20 pm
content: I'm racking my brain on this. I need a binary counter circuit that counts by 8, from 0 to 128 at which point it resets. So, 0 (tick), 8(tick) ... 120(tick), 128(reset). There must be a simple and obvious solution, but I cannot see it. I don't want to use a microcontroller. I want to do it with 74 series logic only, if possible. If someone could point me in the right direction, I'd greatly appreciate it.

author: langwadt
author_rank: Super Contributor
timestamp: February 02, 2025, 09:40:05 pm
content: count 0-15 and stick on three zeroes

author: Benta
author_rank: Super Contributor
timestamp: February 02, 2025, 09:47:03 pm
content: Quote from: langwadt on February 02, 2025, 09:40:05 pmYep. Doesn't get simpler than that.Should be three LSB zeroes BTW.

author: MarkS
author_rank: Unknown
timestamp: February 02, 2025, 10:16:46 pm
content: Quote from: langwadt on February 02, 2025, 09:40:05 pmYep! I just came to say that I figured it out. I feel stupid!I need one 4-bit counter for the high nibble, counting up by one for each tick, and the low nibble just has the lower three bits tied low with the 8's place toggling every tick. When the 128's place goes high, clear the counter.(See langwadt's solution)*edit* Added screenshot of Logisim sketch for any future travelers.

author: langwadt
author_rank: Super Contributor
timestamp: February 02, 2025, 10:24:19 pm
content: Quote from: MarkS on February 02, 2025, 10:16:46 pmyou don't even have to reset, 3+4 bit is only 0-127

author: MarkS
author_rank: Unknown
timestamp: February 02, 2025, 10:27:13 pm
content: Quote from: langwadt on February 02, 2025, 10:24:19 pmCorrect and that is much more elegant.
How to interface with cheap MC'ers - Page 1
Forum section: electronics / beginners

author: Ram80
author_rank: Contributor
timestamp: May 05, 2024, 10:21:54 am
content: I trying to understand what HW/SW to use for the cheap MC's such as the pms150c. Could you use the pickit3 for example?

author: Nominal Animal
author_rank: Super Contributor
timestamp: May 05, 2024, 11:03:59 am
content: I'd useFree PDK.
How to internally connect 2 charging FPCs? - Page 1
Forum section: electronics / beginners

author: idoit
author_rank: Contributor
timestamp: April 17, 2023, 09:23:27 pm
content: Hi everyone,I have 2 FPC charging cable for a phone, they are both USB type-C. In photo 1, the one of the left is female and the one on the right is male. Right now the way power is distributed is the male and female ports connect externally (as shown in 4th photo). What I want to do is to connect them internally. Intuitively, I think there are two options (in 3rd photo).How do you all think this can be done? Thanks!
How to interpret line regulation of LDO expressed as percentage per volt? - Page 1
Forum section: electronics / beginners

author: Jim from Chicago
author_rank: Regular Contributor
timestamp: October 15, 2021, 03:59:51 pm
content: I'm reading the datasheet of an LDO and it says under line regulation 0.03%/V. The output of this LDO is 2.8V. Do you just multiply 0.03 * 2.8V to get 84mV?I'm having trouble because I'm trying to compare this part against another part, and the other part expresses line regulation in plain milliVolts. This other part just says "2mV typ" for line regulation. How do I compare these parts?

author: TimFox
author_rank: Super Contributor
timestamp: October 15, 2021, 04:07:55 pm
content: "Line regulation" is a misnomer that has been used for years. Nothing regulates the line or the input. Modern nomenclature is closer to "source effect" or similar. The sibling of "line regulation" is "load regulation", the change in output voltage with load current.It really means the effect of (change in the input voltage) on (change in the output voltage).0.03%/V means that if the voltage at the input pin changes by 1 V (within the usable input voltage range), the output voltage will change by less than 0.03% of the nominal 2.8 V output, or 0.84 mV. Since the operating range at the input is > 1 V, the range of output voltages over all possible operating input voltages will be higher.The other part is poorly specified if your quotation is the complete statement, but probably means that over the specified "operating" range of input voltage, the output will change by < 2 mV typically, but not guaranteed.

author: Jim from Chicago
author_rank: Regular Contributor
timestamp: October 15, 2021, 04:17:24 pm
content: The full specification for line regulation for the other part is (Vin = Vout + 1V to 12V, Iout = 10ma). 2mV typ, 20mV max.Thanks I think I'm getting a better grasp of it now.

author: rstofer
author_rank: Super Contributor
timestamp: October 16, 2021, 06:17:23 pm
content: Can you breadboard an example circuit and then vary the input voltage while measuring input and output voltages? Lab experiments explain so much!

author: Benta
author_rank: Super Contributor
timestamp: October 16, 2021, 06:25:08 pm
content: Quote from: Jim from Chicago on October 15, 2021, 04:17:24 pmThat means that at an output voltage of 2.8 V, input voltage is 3.8...14.8 V for the "line regulation" specification.
How to interpret this MOSFET Rds(ON) spec - Page 1
Forum section: electronics / beginners

author: nuno
author_rank: Frequent Contributor
timestamp: November 11, 2018, 01:22:13 pm
content: Hello All,I'm looking at the RDS(ON) spec of this MOSFET in the datasheet but it's specified a little different from what I'm used to see.https://toshiba.semicon-storage.com/info/docget.jsp?did=12867&prodName=TK100E10N1Usually they give you the maximum RDS(ON) @ 25ºC (3.4mOhm) and then a normalized graph over temperature, so you just pick the worst (max) value and multiply by the vertical axis value from the graph at the temperature you want to know.This datasheet just gives the max RDS(ON) @ 25ºC but then the graph over temperature is not normalized, the vertical axis is resistance. From the graph value at 25ºC we can see they are using the nominal RDS(ON) at 25ºC (2.8mOhm). What do I do to get the worst value? Do I just shift up the graph by 0.6mOhm (3.4 - 2.8 )?It's also "funny" that the graph is over Ta(ambient) and not Tj(junction)... Japanese "typo"?Many thanks!

author: ocset
author_rank: Super Contributor
timestamp: November 11, 2018, 01:28:52 pm
content: Yes it must be a typo...that graph should be against T(channel)Yes...read it off for your channel temperature, then multiply it by (3.4/2.to give the worst case rdson.(dont know why "2.8" came out like that)

author: Audioguru
author_rank: Super Contributor
timestamp: November 11, 2018, 02:25:36 pm
content: Isn't Toshiba the company who made a "better" TL071 opamp? It was faster. But most of them oscillated then were recalled and replaced.

author: aheid
author_rank: Regular Contributor
timestamp: November 11, 2018, 03:41:20 pm
content: Quote from: treez on November 11, 2018, 01:28:52 pmSimilar to how a smiley is a colon followed by a closing parenthesis, the smiley with glasses is 8 followed by a closing parenthesis.

author: Ice-Tea
author_rank: Super Contributor
timestamp: November 11, 2018, 03:48:06 pm
content: Ta is not a typo. It is a pulse test. So before the pulse is enabled, the die will be at Ta.
How to invert the function of the Fn key on a keyboard? - Page 1
Forum section: electronics / beginners

author: Kahenraz
author_rank: Contributor
timestamp: August 10, 2019, 01:53:47 am
content: I bought a brand new wireless keyboard which I happen to like. However, it has inverted all of the function keys (F1, F2, F3, etc) so that I have to press the "Fn" key to use them.Is there a small circuit that I can make to invert the behavior of this key such that it is always active until I press it? I can confirm through testing that this does not appear to cause a problem with any of the other keys.I am a electronics hobbyist and can build small circuits as necessary. But I'm still inexperienced at how to modify things to create certain behavior.This is a membrane type of keyboard (it's very thin) so I would expect that I would have to use an x-acto knife to shave off some of the plastic to get to the trace and then use a very thin wire and a steady hand to solder anything to this, hopefully without it breaking or melting. I won't know if it will work until I try!Here is the keyboard I ordered:https://www.amazon.com/gp/product/B075SY8XRM

author: Fergo
author_rank: Newbie
timestamp: August 10, 2019, 03:23:39 am
content: You can usually change this behavior by pressing FN+Esc on most keyboards. It will toggle between regular mode or "FN always on".

author: Kahenraz
author_rank: Contributor
timestamp: August 10, 2019, 08:13:13 am
content: Well, HEY! I tried that and it turned on a little light at the top with a "Fn" inside the picture of a lock. It's actually a feature.Thank you!I'm still interested in the circuit as an exercise all the same.

author: ledtester
author_rank: Super Contributor
timestamp: August 10, 2019, 10:37:10 am
content: Quote from: Kahenraz on August 10, 2019, 08:13:13 amComputer keyboards are implemented as a switch matrix which is scanned by sort some of digital logic - a microcontroller, keyboard controller, etc. It would be very difficult to modify the switch matrix or insert some circuitry between the switch matrix and keyboard controller to modify its behavior. In fact, it would probably be easier to replace the entire keyboard controller.Here's a video which explains how keyboards are scanned:
How to investigate PSU noise problem? - Page 1
Forum section: electronics / beginners

author: rudika79
author_rank: Regular Contributor
timestamp: September 07, 2016, 03:05:35 pm
content: What is a best way to investigate PSU noise problem?

author: Ranger14
author_rank: Regular Contributor
timestamp: September 07, 2016, 03:25:51 pm
content: Do you have a scope ??Also you could try filtering or maybe powering with a battery to see if the noise goes away..

author: pix3l
author_rank: Regular Contributor
timestamp: September 07, 2016, 03:26:38 pm
content: What kind of PSU? What kind of noise? You could be a lot more specific..

author: JS
author_rank: Frequent Contributor
timestamp: September 07, 2016, 10:12:08 pm
content: Attach a noise meter to each stage and see which one is generating it and/or which one isn't filtering it out.JS

author: David Hess
author_rank: Super Contributor
timestamp: September 08, 2016, 07:40:07 am
content: Use an oscilloscope to characterize the noise. Line triggering will reveal if power line ripple is a problem. External triggering will reveal if it is switching noise.
How to keep signal at original stength when terminating at 1 or 2 points? - Page 1
Forum section: electronics / beginners

author: Pasky
author_rank: Regular Contributor
timestamp: February 25, 2016, 06:14:41 pm
content: I have a 5Vpp signal I'm generating with two possible output points. I would like both output points to have the signal at 5Vpp regardless of whether it's outputting at one of them or both at the same time. The only way I know how to do this would be to amplify the signal to 10Vpp and then divide it back down for both outputs.Is there any sort of buffering circuit that can be made to accomplish this in another way? I'd love to do it without having to amplify the signal and then divide it back down twice especially if I can just buffer the source signal rather than have an amp and 2 dividers at each output.Thanks in advance for any help you can provide.

author: Audioguru
author_rank: Super Contributor
timestamp: February 25, 2016, 08:41:35 pm
content: A buffer has a very low output impedance that can drive one or many output points without dropping its output level if the output points have fairly high impedances.Your electrical system has a very low output impedance and you can load it with one or many lights or other electrical products and its voltage does not change.

author: Alex Trofimov
author_rank: Contributor
timestamp: February 25, 2016, 08:51:48 pm
content: From your description I assume that the loads have relatively low impedance. In this case the standard way of doing this is to put buffer amplifiers (with unity gain) on both outputs. I'm not certain what this buffers should be without knowledge of specifics of your circuit and your signal, but the first thing that comes in mind is regular op amp arranged as noninverting buffer. You can use package with two amps in one IC.

author: Zero999
author_rank: Super Contributor
timestamp: February 26, 2016, 08:28:39 pm
content: Is it analogue or digital?Frequency?Source & load impedance?
How to know if my logic IC is fried? - Page 1
Forum section: electronics / beginners

author: Agnivesh
author_rank: Newbie
timestamp: November 25, 2012, 06:32:34 am
content: NOOB question:My friend asked me to help him with a science project. The idea is just to make an OR gate using a74HC03quadNAND gate IC.He had previously connected it to a 9V battery, and NOT a 5V supply.Does that do any damage? Could it have fried the IC or is it safe to use it with 9V?And also,is there a way to be sure that the IC is not fried?Like testing resistance between pins or continuity or something else?

author: amyk
author_rank: Super Contributor
timestamp: November 25, 2012, 06:37:01 am
content: 7V absolute maximum according tothe datasheet. Definitely NOT recommended to operate with 9V.The way to test it is to check that the gates function as expected and within spec. Some damage may have occurred that isn't evident but may cause failure later on.

author: SH@RK
author_rank: Contributor
timestamp: November 25, 2012, 08:24:43 am
content: I do not know if there is any special test but you only need to test each gateSo put your IC in a breadboardthen wire it as in this picturesthen add an LED to the output pin and to the ground (so it will turn on when the output is 1 )just check if this table is true ---- If output same as table your IC is not damaged

author: Agnivesh
author_rank: Newbie
timestamp: November 25, 2012, 01:04:38 pm
content: thanks everyone for helping me out!!

author: hlavac
author_rank: Frequent Contributor
timestamp: November 25, 2012, 07:44:55 pm
content: Just get a new one to be sure, they are dirt cheap...

author: vk6zgo
author_rank: Super Contributor
timestamp: November 26, 2012, 12:08:31 pm
content: Usually,if you have cooked a particular gate,its resistance to ground will be different to the other gates,but in this case you might have killed the whole thing.Ashlavacsays,get another one--just treat 'em like 14 legged fuses!

author: deephaven
author_rank: Frequent Contributor
timestamp: November 26, 2012, 12:39:29 pm
content: Also be aware that these chips are Open Drain outputs which means you will have to have a pull-up resistor to see any output.If you want something that runs directly off 9 volts, use CMOS logic.
How to know if two parts are compatible with each other - Page 1
Forum section: electronics / beginners

author: Morad Tamer
author_rank: Contributor
timestamp: April 16, 2017, 05:12:44 pm
content: So I am thinking about getting a new soldering station because my current soldering Iron has gone nuts and is burning every thing it touchesIt reached a point where I (with not so long time) can eventually cut Strip/Vero boards with it and because I don't want to get cheapo Chinese ones and have them break on me after short time or set my house on fire the best I can get without braking the bank is thePro'sKit SS-989BBut I don't know if the listed tips on the retailer's site are for/compatible with this station or not because if they aren't I won't buy it since this the biggest complaint for my current one (after burning everything of course)They are the5SI-216N-1.6D5&SI-216N-B1.0Please don't tell me to google itI have spent the past 2 hours doing so without any helpAny idea is appreciatedThanks a lot in advance

author: NottheDan
author_rank: Frequent Contributor
timestamp: April 16, 2017, 06:13:05 pm
content: Use the contact form and ask.

author: Morad Tamer
author_rank: Contributor
timestamp: April 16, 2017, 07:16:30 pm
content: That's a good ideaThanks a lot

author: wraper
author_rank: Unknown
timestamp: April 16, 2017, 07:23:19 pm
content: They are just yet another Hakko knockoff. There are tons of such tips, interchangeable between various solder stations of such style, none of them as good as genuine Hakko.https://www.hakko.com/english/tip_selection/series_900m.html

author: Morad Tamer
author_rank: Contributor
timestamp: April 16, 2017, 11:27:18 pm
content: I don't about that but to my knowledge Pro'sKit is well known manufacturer so i don't think it is knock off yet still if it is it won't set my house on firePlus this the best brand in my country

author: yada
author_rank: Frequent Contributor
timestamp: April 17, 2017, 12:08:02 am
content: If you watch enough of the DIY vids they all have the same yellow and blue colour in the back ground. That's a hakko. Most are around 120 CAN (Canadian pesos, not sure about lyre of what ever you country uses.)

author: Morad Tamer
author_rank: Contributor
timestamp: April 17, 2017, 12:18:25 am
content: yeah I know Hakko and how great and flawless they areThanks for the HelpBTW 120 CAD is 1700 Egyptian Pounds
how to learn electronics? - Page 1
Forum section: electronics / beginners

author: Kilobytez95
author_rank: Newbie
timestamp: October 20, 2013, 10:24:14 pm
content: I am 18 years old and I am totaly new to this forum but I love watching the EEVBlog videos. I love to tinker with things and take them apart. but sadly i don't know much about electronics design or anything. I know like the very basics like how to build a simple AC to DC power supply with a linear transformer but thats about it. i want to learn more but i don't know where to start.Do you know of any books or something that I could read to learn a bit more or links online that I could visit and maybe pick up a few things?

author: scott216
author_rank: Regular Contributor
timestamp: October 20, 2013, 10:44:17 pm
content: Checkout learn.adafruit.com. They have lots of great electronic projects with very detailed tutorials.

author: mmilejski
author_rank: Contributor
timestamp: October 20, 2013, 10:44:33 pm
content: One of the resources I really like iswww.electronics-tutorials.ws/. It covers fair amount of theory nicely divided into a few page tutorials. If you want a book, Art of Electronics by Horowitz and Hill is a really great reference to have.Also watch the EEVBlog, read the forum, and you'll learn really fast.

author: Kryoclasm
author_rank: Regular Contributor
timestamp: October 20, 2013, 11:07:41 pm
content: Art of Electronics 2nd edition.There are some low cost versions on ebay, the paperback red cover ones.The 3rd edition will be out soon by what I have seen on this forum, but don't wait for it, get it when you can in addition to the 2nd edition.
How to limit the current for hedge trimmer? - Page 1
Forum section: electronics / beginners

author: Fliz
author_rank: Contributor
timestamp: September 15, 2013, 12:54:54 am
content: Hi guysso, here's the situation with which I need a bit help:I have a accu hedge trimmer but no battery for it, genuine battery was NiCd 24V /1700mAh.Since I have good amount of laptop Li-ion 18650 batteries I thought to use them and make new battery pack with6 x 18650 in series which will give me 25.2V max (18V min).I did that, tried it out and it works but, trimmer doesn't have any electronics inside, just one micro switch rated for10A and that's it, so I think I can't just connect batteries directly! In my short, couple of seconds testing I measuredconsumption and it pulls about 2.6A but is that 2.6A from each of 6 cells (so, total of 15.6A) or is that 2.6A for all 6 cells?If it's the 15.6A case then I need to limit the current under the 10A, I think that 4A - 6A would be ok?!What would be the easiest way to do that?Thanks

author: Zero999
author_rank: Super Contributor
timestamp: September 15, 2013, 03:22:54 pm
content: A 5A automotive fuse or pollyswitch will do the job.

author: Fliz
author_rank: Contributor
timestamp: September 15, 2013, 09:48:46 pm
content: So, it is 2.6A in total, that's great.For recharging I will use Turnigy Accucel-6 hoby charger/balancer but until I buy this balancer I will use Nitecore I4 charger, I will build battery pack that way the 18650 cells could be removed and charged individually.Also, because this batteries are unprotected (so, no way to stop them discharging under 3V) I bought this:2-in-1 1~8S Lipo Battery Low Voltage Buzzer Alarm for RC Helicopterwhich should help me keep an eye on batteries status. I am still not sure how alarm works on this thing but I hope that it fires of if any of the cells in 6S goes under let say 3V...Also, idea about 5A automotive fuse is good, very easy to implementI think that this solution should be pretty secure?!
How to load sketch atmega328p with bootloader ? - Page 1
Forum section: electronics / beginners

author: abdullahseba
author_rank: Frequent Contributor
timestamp: May 13, 2017, 08:47:11 pm
content: HiI have a atmega328p with the arduino bootloader installed but cant find out how I would load a sketch on to it without plugging it into the uno.I need to do this in circuit because I later will be using the TQFP version of it.Is there any way to do this with an existing arduino or do I need another programmer?Thanks in advance.

author: igendel
author_rank: Frequent Contributor
timestamp: May 13, 2017, 09:04:24 pm
content: Do you wish to preserve the existing bootloader on the chip?If so, I think you can take a regular UNO (the kind with a DIP chip), take the chip out of it, and connect the RX, TX and Reset pins from the board to the appropriate pins on the standalone chip. Then burn the sketch from the Arduino IDE as usual. Don't forget the 16MHz crystal and all that[Edit: and connect the Grounds too!]

author: abdullahseba
author_rank: Frequent Contributor
timestamp: May 13, 2017, 09:21:26 pm
content: I did try that but it the IDE just uploaded forever untill error.

author: igendel
author_rank: Frequent Contributor
timestamp: May 13, 2017, 09:28:40 pm
content: Quote from: abdullahseba on May 13, 2017, 09:21:26 pmPlenty of things can go wrong... but check your connections carefully, it should work.See here:https://www.arduino.cc/en/Tutorial/ArduinoToBreadboard(mainly the "Uploading Using an Arduino Board" section, but it won't hurt to read the rest)[Edit: that page is old, stating "Arduino Duemilanove" - you'd probably want to choose "Arduino Uno" instead]

author: abdullahseba
author_rank: Frequent Contributor
timestamp: May 13, 2017, 10:22:10 pm
content: No connections are fine It runs circuits fine.

author: igendel
author_rank: Frequent Contributor
timestamp: May 13, 2017, 10:39:16 pm
content: Hmm... well, there's only so much I can do without testing the circuit myself, sorry. But again, this is a very common procedure, itshouldwork, so keep looking. Is there something else interfering with the reset/RX/TX lines? Is there sufficient power? etc. etc.

author: abdullahseba
author_rank: Frequent Contributor
timestamp: May 13, 2017, 10:48:44 pm
content: Ah it does work, had the RX/TX the wrong wayFirst time didn't work cuz I kept the chip in and tied the uno's reset to ground to act as a USB to TTL.Thanks

author: igendel
author_rank: Frequent Contributor
timestamp: May 13, 2017, 11:21:13 pm
content: Quote from: abdullahseba on May 13, 2017, 10:48:44 pmOne of the most common mistakes. Someone else here made the same one just a couple of days ago:https://www.eevblog.com/forum/microcontrollers/troubleshooting-custom-arduino-nano-board/msg1203081/#msg1203081
How to lower voltage - Page 1
Forum section: electronics / beginners

author: Jane
author_rank: Frequent Contributor
timestamp: September 14, 2021, 12:48:41 pm
content: I use this digital multimeterhttp://www.range.com.hk/products/RE890G.htmlworks great but it needs battery 9V to function. I have a power supply adaptor but it provides 12V, 3A.What ways would you suggest so that I can use that adaptor with the multimeter? I was thinking about a resistor connected between multimeter and the power supply.From my calculation it seems 0.25M Ohm could lower those 12V to 9V.Is it possible?Thank you for your hints

author: Vovk_Z
author_rank: Super Contributor
timestamp: September 14, 2021, 12:57:03 pm
content: 1. It is bad (wrong) and inconvenient to use handheld multimeter with a mains-powered power supply.2. It is wrong to use a single series resistor to lower the voltage because current consumption vary much.3. Just buy a 9V battery (I buy at least two usually).

author: tszaboo
author_rank: Super Contributor
timestamp: September 14, 2021, 01:02:48 pm
content: Please dont. You will either electrocute yourself or blow up the electrical network.

author: comfortcube
author_rank: Contributor
timestamp: September 14, 2021, 01:07:29 pm
content: The reason it is not good to power your multimeter from mains power is because now (I believe) the negative terminal on your meter becomes Earth ground, or at least Earth ground referenced, and depending on where you place it in your circuit, you can easily cause something to blow up or get damaged or hurt yourself. Such meters need to remain "floating" in terms of their power supply, which is why they are battery powered.Also, the resistance you calculated would lower the voltage to the 9V you want only at the current you used to calculate; the current draw will certainly vary and cause that voltage to fluctuate. Also in general, this is not how voltage regulation is done at all.

author: Zero999
author_rank: Super Contributor
timestamp: September 14, 2021, 01:10:43 pm
content: If it's only to be used for measuring extra low voltage, i.e. <60VDC, then it's safe to use your power adaptor with the LM7808 to reduce the voltage to power the meter, but it shouldn't be connected to any other circuits, powered from the same power adaptor, otherwise it might not work properly, or be damaged.As many others have stated: this is a bad idea. If you want a mains powered mulitimeter, use a bench top unit.https://www.rigol-uk.co.uk/product/rigol-dm3058e-5a%C2%BD-digit-digital-multimeter/
How to make 3 different voltages in a circuit? - Page 1
Forum section: electronics / beginners

author: q12
author_rank: Contributor
timestamp: April 24, 2020, 06:48:34 pm
content: I have 1 circuit composed from 3 little very simple circuits I want to power them all from a 5V@1A power source.All of these 3 circuits must be powered at different voltages.Their current draw I measured for each of them.A=4V @10mA, B=3.4V @1.6mA, C= 5V @24mAWhat can you suggest?Thank you.

author: Nusa
author_rank: Super Contributor
timestamp: April 24, 2020, 07:01:26 pm
content: Obviously C is already handled.As for A and B likely some resistors to make a "voltage divider" (look it up) would do the trick.

author: q12
author_rank: Contributor
timestamp: April 24, 2020, 07:04:20 pm
content: Thank you.

author: Manul
author_rank: Super Contributor
timestamp: April 24, 2020, 07:28:18 pm
content: Two adjustable LDO regulators set for 4V and 3.4V.

author: themadhippy
author_rank: Super Contributor
timestamp: April 24, 2020, 07:39:55 pm
content: Diodes,maybe a milli volt or 2 out,but it's should be close enough

author: WattsThat
author_rank: Frequent Contributor
timestamp: April 24, 2020, 08:24:17 pm
content: A voltage divider is not a power supply. The output voltage will change with load and the absolute value of the resistors. Yes, for a few ma it might work but...You would get far better answers if you provided more detail about the actual circuits.

author: james_s
author_rank: Super Contributor
timestamp: April 24, 2020, 08:44:29 pm
content: Feed an emitter follower with a voltage divider and you have a power supply. A more robust solution is to use 3 terminal regulators but a simple transistor regulator may be sufficient.

author: Zero999
author_rank: Super Contributor
timestamp: April 25, 2020, 05:49:47 pm
content: An op-amp can be added to a potential divider to reduce the output impedance. Choose an op-amp which can source at least 10mA, with its output 1V below the supply voltage and can operated with its inputs within 1V of the positive rail, such as the MCP6002.http://ww1.microchip.com/downloads/en/DeviceDoc/MCP6001-1R-1U-2-4-1-MHz-Low-Power-Op-Amp-DS20001733L.pdf

author: Siwastaja
author_rank: Super Contributor
timestamp: April 25, 2020, 05:56:40 pm
content: Linear regulator ICs! Use modern ones which are stable with ceramic output capacitance.
how to make a pulse motor  - Page 1
Forum section: electronics / beginners

author: Ian
author_rank: Contributor
timestamp: January 26, 2011, 12:59:06 am
content: Hiso i have seen all the videos about pulse motor and i think there really cool. But how do i make one? do i have magnets that are all have there north pole facing out on a disk that can spin freely. then i have a electromagnet with a reed switch close enough so when the magnets on the disk come by they turn on the electromagnet and then the electromagnet makes the whole think spin?

author: Zero999
author_rank: Super Contributor
timestamp: January 26, 2011, 07:43:47 pm
content: You mean a brushless DC motor?Using reed switches is not a good idea because they're not designed to work at such high frequencies and will soon fail. Use hall effect sensors which are semiconductor devices and will not wear out.