hybridfree/eevblog-posts huggingface dataset:
What is causing this voltage spike at the output of a MOSFET? - Page 1
Forum section: electronics / beginners

author: canadaboy25
author_rank: Regular Contributor
timestamp: August 10, 2021, 06:30:33 pm
content: Hey everyone,I am working on a plasma TV that had some shorted MOSFETs in the Z-Sustain driver module. I replaced the shorted FETs with some Panasonic 5N2307 FETs that I pulled off a scrap board from another TV. The TV powered up and worked perfectly. However, shortly after powering it up, both FETs shorted again. I assume either the voltage or current ratings were not high enough but it is hard to tell as there is no datasheet available for these.I got some FDB12N50TM FETs that are 500V 11.5A. The TV powers up and stays on without shorting the FETs. However, the image is very poor with lots of ghosting. I saved a waveform of the Z-Sus output with my scope and then reinstalled two more Panasonic FETs and powered up the TV long enough to capture another trace with my scope.Comparing the two waveforms, I can see that the Panasonic FETs provide a nice clean switching output, but the FDB12N50TM FETs have a large voltage spike after each switching event. I have attached a few examples of these voltage spikes. The blue trace is the good waveform with the Panasonic FETs and the red trace is the problematic waveform with the FDB12N50TM FETs. The two traces are a bit out of sync with each other but it is still clear that the red trace has large voltage spikes that should not be there.I have also attached a schematic of the switching module that I reverse engineered from the PCB in case that is helpful for anyone.What parameter of the FETs could be causing these voltage spikes? The original FETs had no markings so I am trying to find a suitable replacement for them. However, I do not know what specification is not correct to be causing these large voltage spikes on the output.If anyone has any ideas, please let me know!

author: Jwillis
author_rank: Super Contributor
timestamp: August 11, 2021, 03:24:27 am
content: Are you absolutely certain they are MOFETs and not IGBTs . I'm by no means an expert on plasma TVs but the last one I encountered (Samsung) had IGBTs on the driver boards . IGBTs can handle much higher voltages , current , lower duty cycles , low switching losses at high voltage and lower frequencies .

author: canadaboy25
author_rank: Regular Contributor
timestamp: August 11, 2021, 03:30:48 am
content: Quote from: Jwillis on August 11, 2021, 03:24:27 amI'm fairly certain that you are correct. It seems they were originally IGBTs. There is a diode across both transistors that should not be necessary if they were originally MOSFETs.I found this youtube video just before you replied:The guy is repairing one of these modules and it seems he made the same mistake as I did. He used a FGD4536 PDP Trench IGBT as a replacement.The FGD4536 is no longer stocked on digikey or mouser and I am having trouble finding a Trench IGBT in the D2PAK package on mouser or digikey. I ordered some FGD4536 IGBTs on ebay from China for a few bucks. It will likely be a month before they are here. Hopefully they solve the issue.
what is demo limit error in mikroc? - Page 1
Forum section: electronics / beginners

author: khatus
author_rank: Regular Contributor
timestamp: September 04, 2019, 03:45:05 pm
content: Hello guys what is demo limit error ?I have found a code for Load Cell in online but while compiling it shows Demo limit errorCode:sbit LCD_RS at LATB4_bit;sbit LCD_EN at LATB5_bit;sbit LCD_D4 at LATB0_bit;sbit LCD_D5 at LATB1_bit;sbit LCD_D6 at LATB2_bit;sbit LCD_D7 at LATB3_bit;sbit LCD_RS_Direction at TRISB4_bit;sbit LCD_EN_Direction at TRISB5_bit;sbit LCD_D4_Direction at TRISB0_bit;sbit LCD_D5_Direction at TRISB1_bit;sbit LCD_D6_Direction at TRISB2_bit;sbit LCD_D7_Direction at TRISB3_bit;void main(){int adc_rd;float adc_val;float wt;char finaltxt;float quant=5.0/1024;//char res;PORTB =0xFF;TRISB=0xFF;ADCON1=0Xc0;ADC_Init();LCD_Init();lcd_cmd(_LCD_CLEAR);lcd_cmd(_LCD_CURSOR_OFF);while(1){adc_rd = ADC_Read(0);adc_val=adc_rd*quant;wt=(adc_val-0.361)/0.079;sprintf(finaltxt,"%1.2f",wt);lcd_cmd(_LCD_CLEAR);Lcd_Out(1,1,"WEIGHT: ");Lcd_Out(1,9,finaltxt);Lcd_Out(1,14,"KGs");Delay_ms(1000);}}

author: ledtester
author_rank: Super Contributor
timestamp: September 04, 2019, 04:17:22 pm
content: https://www.quora.com/How-do-I-solve-the-problem-of-a-demo-limit-434-error-in-MikroC-Pic-v6-without-purchasing-a-licenseLooks like you need to buy a license.

author: Doctorandus_P
author_rank: Super Contributor
timestamp: September 04, 2019, 06:04:39 pm
content: I am just curious why anyone would bother with expensive or crippled compilers in these days when GCC is freely available for almost any uC worth using.

author: Jeroen3
author_rank: Super Contributor
timestamp: September 04, 2019, 06:19:59 pm
content: With GCC it is expensive to maintain a stable development environment. It's almost exclusively bundled with something that used to resemble eclipse or you have to set it up all yourself.Then two weeks later you're five continuous integration versions behind.When you're not toying around you want to pick a version of a compileryears laterand still be able to install and create an exact reproduction of what you did a long time ago.Basically you have to VM all projects, it's just cumbersome. When you count the lost time license for a paid package suddenly isn't that bad anymore. Since those can be installed side-by-side.So using the "free" stuff comes at a price as well.This is why Open Source projects usually have their own toolchain setup.

author: sairfan1
author_rank: Frequent Contributor
timestamp: September 04, 2019, 06:25:33 pm
content: If you are using PIC uC you can use XC compiler, there are a lot of examples and libraries available.
What is going on in this encoder circuit? - Page 1
Forum section: electronics / beginners

author: Muffins
author_rank: Regular Contributor
timestamp: September 03, 2025, 02:24:13 pm
content: Hi guys,I'm looking at the encoder circuitry on a Trinamics stepper motor driverevaluation board.I'm putting together my own board based on this one. But I'm not sure about what's going on with the circuit on the encoder IO seen here:Can someone explain this?

author: ataradov
author_rank: Super Contributor
timestamp: September 03, 2025, 02:59:10 pm
content: What specifically is not clear? A and B are encoder phases, N is the absolute position marker, I would assume. Encoder will pull-down corresponding pins to the ground. So, you either and an input connected to VCC though 5.7 kOhm resistor, or pulled to the ground though 1 kOhm resistor. Capacitors are for debouncing and TVS diodes are for protection.Given that encoder is powered, it will likely have open-drain output, so it will pull to the ground when output transistor is open.

author: MarkF
author_rank: Super Contributor
timestamp: September 03, 2025, 05:51:26 pm
content: That is the typical suggested filter circuit for encoders(see the Bourns PEC11 encoder datasheet for example).It is a pull-up resistor for each encoder pin followed by alow pass filter for debouncing as @ataradov said.The encoder outputs will be pulled high when not rotating andthen switches of some sort (mechanical or electrical) will pulleach encoder low to provide the proper output sequencing.The diodes are over and under voltage protection. Not normallyfound in most circuits. I suspect they are there because theencoder pins are exposed to inadvertent shorts on an evaluation board.

author: ataradov
author_rank: Super Contributor
timestamp: September 03, 2025, 06:26:50 pm
content: The encoder is likely something like thishttps://www.sparkfun.com/rotary-encoder-1024-p-r-quadrature.htmlBeing close to the stepper motors and potentially running over long wires, EMI is to be expected, so diodes are justified.

author: MarkF
author_rank: Super Contributor
timestamp: September 03, 2025, 07:13:34 pm
content: I'm not sure I understand the function of Phase Z.Is that there to indicate direction or for a sync or what?

author: ataradov
author_rank: Super Contributor
timestamp: September 03, 2025, 07:22:12 pm
content: It is an absolute zero mark. It is toggled along with one of the counts along the full rotation.

author: BeBuLamar
author_rank: Super Contributor
timestamp: September 03, 2025, 10:41:37 pm
content: Quote from: MarkF on September 03, 2025, 07:13:34 pmThe Z pulse is only one per revolution of the encoder (while there are many pulses of the A and B pulses per revolution). It is used to home. Usually when homing there is a sensor of some source to indicate the approximate home then after the controller sees the this it backups until it gets the Z pulse.
What is going to impect replacing a different battery in car remote started - Page 1
Forum section: electronics / beginners

author: sairfan1
author_rank: Frequent Contributor
timestamp: January 19, 2024, 03:26:14 pm
content: I have Nissan car remote starter, it had pre installed CR2016 x 2 batteries inseries(as its a used car I'm not sure if pre installed baterries were correct, unfortunatly I can't read brand/model number of the remote).I had only CR2032 battery (3v) with me so i installed it, remote worked but I want to know, if its going to impect range of remote as in total it was 6v (as CR2016 betteries were installed in series) or this may cause life of battery or anything else?

author: tunk
author_rank: Super Contributor
timestamp: January 19, 2024, 03:32:58 pm
content: Measure the voltages of the old cells, then look at this and make some estimates:https://lygte-info.dk/info/BatteriesLowCurrentDischarge%20UK.html#CR2032,_PanasonicEdit: I thought by "range" you meant battery life. If you mean distance, why not test it?

author: coromonadalix
author_rank: Super Contributor
timestamp: January 19, 2024, 03:40:54 pm
content: their thickness is different you may or will stretch the battery holder or even break it, did you put 2x cr2032 ??

author: sairfan1
author_rank: Frequent Contributor
timestamp: January 19, 2024, 04:00:30 pm
content: QuoteI put only one CR2032 battery, that's why I was wondering how its going to impect the remote.

author: wasedadoc
author_rank: Super Contributor
timestamp: January 19, 2024, 04:14:30 pm
content: Quote from: sairfan1 on January 19, 2024, 04:00:30 pmYou need to ascertain whether the remote is designed to take a single 2032 and someone previously fitted two 2016s of if two 2016s are intended. If the latter a single 2032 is likely to have reduced range and cause the remote to require cell replacement quite quickly.Often there is polarity marking as part of the cover moulding. Does it offer any clues?

author: electr_peter
author_rank: Unknown
timestamp: January 19, 2024, 07:56:56 pm
content: Most car remotes have CR2032 battery inside, but thats is not a strict rule. Check battery change instructions in car manual (or similar model of same manufacturer). 2*CR2016 and 1*CR2032 is very different.

author: coromonadalix
author_rank: Super Contributor
timestamp: January 20, 2024, 05:17:40 pm
content: cr2016 in serial is 6vdc a single cell is 3vdc you miss half the voltage ? guess ...plain stupid move, go buy the right cell

author: mikerj
author_rank: Super Contributor
timestamp: January 22, 2024, 02:32:31 pm
content: Which model Nissan is it? Most Nissan keyfobs in the last 15 years or so take a single cell (CR1220, CR2016, CR2025 or CR2032)
What is gpib and what is it use for? - Page 1
Forum section: electronics / beginners

author: carbon dude oxide
author_rank: Frequent Contributor
timestamp: May 05, 2013, 11:30:01 am
content: Hello i was wondering what a gpib is. I had a look online and found some information like it was a hpib due to it being developed by hp but then later renamed to gpib standing for general perpous interface bus but i was unsure what it was used for

author: ddavidebor
author_rank: Super Contributor
timestamp: May 05, 2013, 11:35:57 am
content: It's use to comunicate with expensive equipment.For comunicate i mean receive data like measurement or the status of the device and control it in every function.It usually has very advanced function like direct access to memory and thing like this.Hovewer, it's old but still used. And it's very expensive, sometimes the cable cost what you paid for the tes gear.It's used for automated measure first.

author: Unknown
author_rank: Unknown
timestamp: May 05, 2013, 11:38:25 am
content: It used to be a general purpose interface (as the name suggests) that was used for test equipment, but also some computer peripherals and plotters. These days it's almost exclusively used for interfacing with legacy test equipment. Test equipment from the eighties will usually only have a GPIB interface. Test equipment from the nineties might also feature RS-232. USB and LAN became common on test equipment somewhere in the past ten years.For example, the HP 3478A and 3457A DMMs that Dave has showed in his videos feature a GPIB interface. This allows you to record measurements to a computer (could have been useful for the Gaussian resistance measurement experiment) or control the instrument from a computer. You need a GPIB interface (eg. a USB-to-GPIB interface) and software that can talk to the instrument. LabView is the 800 lbs gorilla here.New instruments might have a GPIB interface for compatibility with legacy systems, but in general it's quite rare on new equipment these days. GPIB was designed for automated test equipment systems, and has some special features for ATE like SRQ interrupts (instruments signal the controller when they have data) and parallel triggers.
What is H-type biasing? - Page 1
Forum section: electronics / beginners

author: circuit975
author_rank: Contributor
timestamp: May 15, 2024, 06:02:52 am
content: What does h-type biasing mean? I'm learning it at school, does anyone know what it means?

author: CaptDon
author_rank: Super Contributor
timestamp: May 15, 2024, 12:28:55 pm
content: Search Engine? Google? I've never heard of H-Type biasing? Guess we could all google it. Maybe H-Type is a fancy name for something we all knew all along? Like when the politically correct folks came up with the term 'Handi-Capable'.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: May 15, 2024, 01:59:16 pm
content: 'H' probably refers to an "H bridge" arrangement (the reference is evident from the schematic), or a class-H amplifier (class AB with sliding power supplies to maximize efficiency). But neither is a state or method of bias.Tim

author: mag_therm
author_rank: Frequent Contributor
timestamp: May 15, 2024, 02:38:25 pm
content: It might be just the classic 4 resistor bjt bias method, resembling H with transistor in the middle.

author: Aldo22
author_rank: Super Contributor
timestamp: May 15, 2024, 02:45:43 pm
content: Could it have something to do with that? (I have no idea)https://en.wikipedia.org/wiki/Bipolar_junction_transistor#h-parameter_model
What is happening in this circuit? optocoupler and igbt - Page 1
Forum section: electronics / beginners

author: elektronJack
author_rank: Contributor
timestamp: July 24, 2019, 01:56:50 am
content: What is happening in this circuit? There is a diode on the red line allowing current to flow from left to right. There is a 25v 47 microF capacitor on the blue line, + side on the left (these are on the other side of the board)
What is Hardware QTouch Acquisition on Atmel MCUs? - Page 1
Forum section: electronics / beginners

author: Robert.Adams
author_rank: Contributor
timestamp: August 19, 2014, 01:05:35 am
content: So after a bit of searching and still not finding anything relevant, does anyone know what Atmel means when they say a microcontroller has Hardware Qtouch Acquisition?I know Qtouch is their capacitive touch sensing library but their product selector shows a variety of microcontrollers with "touch channels" that don't have the HW Qtouch acquisition. Is this just because they want you to write your own code on those microcontrollers? That wouldn't be hardware if that was the case. I saw a forum where someone suggested they might need less external components for the ones with Hardware Qtouch support but nothing I've found (in AVR259 or elsewhere) supports this.Edit: Ooops, this probably belongs in the microcontroller section of the forums.

author: Nerull
author_rank: Frequent Contributor
timestamp: August 19, 2014, 02:10:52 am
content: As far as I can see, chips with hardware qtouch support do not require external capacitors and use only one pin per channel, while those without it need an external capacitor and two pins per channel.
What is "high density glass fabric PCB"? - Page 1
Forum section: electronics / beginners

author: ballsystemlord
author_rank: Frequent Contributor
timestamp: November 09, 2023, 02:15:34 am
content: Hello,Ever since I first learned about PCBs, I've wondered what on earth a "high density glass fabric PCB" as described, for example, below was. I thought maybe FR4, but then what would "traditional" be? I read about the types, but nothing really seemed to fit the descriptions given.Does anyone know what PCB material is being described in the picture?Also, aren't the layers coated in epoxy such that humidity wouldn't be a problem unless the epoxy was compromised?Thanks!EDIT: Added second q.

author: ataradov
author_rank: Super Contributor
timestamp: November 09, 2023, 03:16:56 am
content: This is someone in the marketing department doing their job.Note that there are materials with different density of the weave. They all are FR-4. FR-4 is not a specific material, it is a class of materials. Within this class there are better and worse quality materials.High-speed devices tend to use better quality materials because at those speeds the weave pattern affects signal propagation and cheaper material may not work as well electrically.It has nothing to do with water creating shorts. But the real thing is much harder to explain in the marketing material. And marketers try to use anything as a bullet point.
what is HP4145A? - Page 1
Forum section: electronics / beginners

author: SDBFG
author_rank: Contributor
timestamp: April 23, 2018, 10:28:10 am
content: hello siri find this in Google HP4145A what does it do?

author: joeqsmith
author_rank: Super Contributor
timestamp: April 23, 2018, 10:39:36 am
content: Quick check on Googlehttps://youtu.be/ZCxzYmUX3WA

author: SDBFG
author_rank: Contributor
timestamp: April 23, 2018, 02:01:32 pm
content: Quotewhat does it do?
What is kelvin point in circuit? - Page 1
Forum section: electronics / beginners

author: OverMyHead
author_rank: Newbie
timestamp: March 11, 2022, 01:41:46 am
content: Could someone please help to explain what is kelvin point? Is it just a specific connection point(intersection of measurement path and regular path) in the circuit?Thanks!

author: TimFox
author_rank: Super Contributor
timestamp: March 11, 2022, 01:57:50 am
content: I've never heard of a Kelvin point, myself. Do you mean a Kelvin connection? That involves four wires and can be found by Googling.

author: magic
author_rank: Super Contributor
timestamp: March 11, 2022, 05:31:14 am
content: Quote from: OverMyHead on March 11, 2022, 01:41:46 amMost likely this was meant.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: March 11, 2022, 06:01:25 am
content: There are probably several buried meanings in the phrase, all tied back to Kelvin connections as mentioned in the previous post.Some point in the circuit, often the input to an OP amp or other high gain component needs to act on a voltage that is not affected by real world factors such as trace resistance or other currents which may use some part of the same trace. A stub trace from that point goes off to the sensing point (and possibly also a test point). Everything which is connected to the stub has high impedance so negligible current flows in the stub and as a result the voltage is the same at any point on the stub line. (In the static or non-time varying case).The only sure way to know what was meant is to ask the author.

author: OverMyHead
author_rank: Newbie
timestamp: March 14, 2022, 05:11:16 pm
content: Quote from: CatalinaWOW on March 11, 2022, 06:01:25 amThanks for the explanation! I think this is what is means.
what is kelvin type resistor ? - Page 1
Forum section: electronics / beginners

author: saeed.GH
author_rank: Newbie
timestamp: August 17, 2017, 09:52:58 am
content: Four-terminal sensing for sensing resistor very exactly . what is their principle of operation?please help me , I wanted make sense resistor 0.001 ohm to 1000 ohm ?

author: ElektronikLabor
author_rank: Regular Contributor
timestamp: August 17, 2017, 10:11:16 am
content: Hello and welcome!Did you already read that article?https://en.wikipedia.org/wiki/Four-terminal_sensingWhen you have very small resistors for sensing current you get inaccuracies that are caused by the resistance of the resistor leads.The extra two sense leads cancel out that extra resistance; because (normally) no current flows through them.

author: Rerouter
author_rank: Super Contributor
timestamp: August 17, 2017, 01:49:02 pm
content: 4 wire sensing is a high accuracy way to measure currents, or resistances, depeding on your application,The goal is to have your measuring points for the voltage across the resistor to be taken at a point where you know your resistance value is exactly as you specify, and ideally where outside influences cannot greatly change the voltage your measuring4 lead kelvin smd resistors are designed so there is dedicated measuring points on the body of the resistor.If you approach it with a normal 2 lead 0.01 ohm resistor on a PCB, firstly you will have added resistance from the copper traces, and this changes with temperature, which when your traces might make up 1% of the resistance value, mattersBy seperating off those 2 leads, all the current flows between the main pads, but your measuring exactly across those measuring points, as you will be measuring with a high impedance meter or amplifier of some kind, you can treat it as a voltage, and that trace resistance no longer matters, maybe attributing 0.0001%.Now as for how to make a kelvin resistor, this is actually pretty easy, if you pick something like a 1206 SMD you can split the pad in 2, this will remove the solder from changing the resistance across the resistor.for through hole, if your working with high enough precision that you need kelvin sensing your probably in to low temperature coefficient resistor materials, which means you pick 2 points on the lead you want to be your value and loop on a second set of leads for your measuring points,Note that it gets a little hard to make a kelvin decade box, in these approaches the general method is instead of using a copper PCB you instead use low tempco metals and switches to interlink the resistors, and split the sense jacks and current jacks at a point in the box where it reads correctly.A little bit more detail would help, The metrology area of this site has plenty of teardowns of precision decade boxes if thats what your planning to aim for.If you literally want a box full of just 0.001, 0.01, 0.1,1,10,100,1000 ohm resistors with 4 jacks a piece, that is much easier.
What is lost when importing Altium projects into Kicad? - Page 1
Forum section: electronics / beginners

author: Lithium John
author_rank: Newbie
timestamp: February 06, 2020, 10:23:33 am
content: Long time EEVblog viewer, first time forum user.I have been hired to prototype a big lithium ion storage system that will use an open sourced battery management system. However, it will need some adaptation, mainly changing the battery cell monitoring connector and shifting the existing electronics around on the PCB in order to place the connector in the middle of the board. Since we are in the early stage of development, the budget is small and it will be very difficult to purchase Altium (the open source project is an Altium project). It would help us a lot if i could use Kicad for this task, but since it concerns a device where safety is of the highest importance, i am a bit worried that something important will be lost or changed without my knowledge when i import the Altium project into Kicad.Is this a risk? Furthermore, does anyone know what exactly can go wrong such an import?Finally, any and all tips and tricks are welcome since i am a complete beginner when it comes to PCB softwares.Thankfully yoursDaniel

author: thinkfat
author_rank: Unknown
timestamp: February 06, 2020, 10:56:13 am
content: There's "altium2kicad" (https://github.com/thesourcerer8/altium2kicad) but it seems that there a quite some restrictions and uncertainties. No way around it, you'll have to verify board and schematic quite meticulously.

author: pointhi
author_rank: Contributor
timestamp: February 06, 2020, 05:36:07 pm
content: Well, you could start thinking what is impossible to import, like design rules. This simply due to the fact that KiCad does not support them in the same way as Altium models them at the moment. The same with Planes, because KiCad does not know the concept -> importer needs to do a workaround.I'm currently in progress of combining all existing Altium Parser / Importers and integrated them into KiCad:https://forum.kicad.info/t/work-in-progress-native-altium-importerI would suggest to do a diff of the gerber files and carefully think about design-rules, complex padstacks, hirachial schematics,... In case you want to try my importer, please tell me if something is not working as expected.

author: Kasper
author_rank: Frequent Contributor
timestamp: February 06, 2020, 09:09:56 pm
content: Not sure what your budget is but circuit studio is a cheaper version of altium. Its not great, its missing some features like length matching but I like it more than kicad and importing altium files was fairly easy aside from some bugs with layer names.
What is Megatronics? - Page 1
Forum section: electronics / beginners

author: VladKEasternTiger
author_rank: Regular Contributor
timestamp: March 15, 2010, 12:08:16 am
content: Hi gang, I remember a few years back I was working in a supermarket whilst at college and my friend working with me was doing his Masters in Megatronics from India but it had another word before It I cannot remember it, I vaguely remember him telling me he was doing projects designing robots that manufacturing plants use to make products, I looked on Google but no clear definition what Megatronics is, mabie you guys can help me?

author: joelby
author_rank: Frequent Contributor
timestamp: March 15, 2010, 12:11:22 am
content: It sounds like you mean "mechatronics". You'll have a bit more success Googling that.

author: migsantiago
author_rank: Frequent Contributor
timestamp: March 15, 2010, 04:10:42 am
content: hahaYes, it is definitely Mechatronics.Mechanics + Electronics

author: VladKEasternTiger
author_rank: Regular Contributor
timestamp: March 15, 2010, 08:22:07 am
content: Quote from: joelby on March 15, 2010, 12:11:22 amHaha Yeah thanka

author: VladKEasternTiger
author_rank: Regular Contributor
timestamp: March 15, 2010, 08:22:37 am
content: Quote from: migsantiago on March 15, 2010, 04:10:42 amThank you thats what im looking for
what is mosfet Rg - Page 1
Forum section: electronics / beginners

author: electrolust
author_rank: Unknown
timestamp: March 30, 2017, 05:49:58 pm
content: For the NXP PMV20XNEA, IGSS= 5uA @ 4.5V. That can be considered to be R of 900k is it not? So not quite open circuit but still pretty up there.OK, now if that's right, what is the Rg number that the spec sheet mentions? 7r2 @ 1MHz. Would I think of this as the ESR of the capacitance CISS?NXP publishes AN11158, understanding MOSFET data sheets. In that AN they do not describe the Rg parameter!I only looked at one other mfr, Fairchild, and they do not publish any Rg spec.

author: MagicSmoker
author_rank: Super Contributor
timestamp: March 30, 2017, 07:00:57 pm
content: STMicro has an entire application note dedicated to this topic:www.st.com/resource/en/application_note/dm00068312.pdfYou can more or less treat Rg as a resistor in series with the gate terminal.

author: danadak
author_rank: Super Contributor
timestamp: March 30, 2017, 07:24:44 pm
content: Gate leakage current is a static current that is quite complex in its nature,consisting of surface state leakage as well as tunneling and other sourcessuch as contamination.....Google "mosfet gate leakage" and there are a number of papers out thereon this topic, process, oxide thickness......https://nanohub.org/resources/5690/download/2008.10.28-ece612-l16.pdfhttp://inst.eecs.berkeley.edu/~ee130/sp06/chp7full.pdfhttps://nanohub.org/resources/5690/download/2008.10.28-ece612-l16.pdfRg on the other hand is a dynamic parameter associated with gate charging and dischargingbehavior and modeling. eg. switching behavior.http://www.vishay.com/docs/73217/an608a.pdfhttp://www.infineon.com/dgdl/mosfet.pdf?fileId=5546d462533600a4015357444e913f4fhttp://www.aosmd.com/res/application_notes/mosfets/Power_MOSFET_Basics.pdfRegards, Dana.
What is name of IC which is written "601Km" on its surface? - Page 1
Forum section: electronics / beginners

author: bshi02
author_rank: Regular Contributor
timestamp: September 29, 2024, 05:22:36 am
content: Hello.I have T12-952 Soldering Station which is not able to display any screen But When I power on it, iron become hot.I desolder some components to check whether it have been faulty or not, But When I tried to desolder an IC Which is written "601Km" on the surface,I broke leftmost pin like attached photos.I use Mini Drill in order to peel off plastic suface but I cannot found copper sheet which is supposed to be pin3.What is name of IC which is written "601Km" on the surface?and Is there any pdf datasheet about this IC?

author: dustooff
author_rank: Contributor
timestamp: September 29, 2024, 07:02:04 am
content: Hi,I have two of these T12-952 units, both the same fault as you describe, no display.I suspect that the OLED is failed, not exactly sure how yet, one unit had about 2 years of daily use, the other maybe 30 to 40 hours, but both displays failed. The daily driver I could see getting dimmer every day over the last month, until one day nothing.The 601K device I think is a 5V regulator, pinout matches the datasheets in these links, (for GND, Vin & Vout)https://ww1.microchip.com/downloads/aemDocuments/documents/APID/ProductDocuments/DataSheets/TC1014-1015-1185-50-mA-100-mA-and-150-mA-CMOS-LDOs-with-Shutdown-and-Reference-Bypass-Data-Sheet-DS20001335.pdfhttps://www.ti.com/lit/ds/symlink/lp5907.pdfThe pin described as bypass on the Microchip datasheet has connection to the controller on these boards.But not in manner that would provide Bypass characteristic.regardsAndrew

author: bshi02
author_rank: Regular Contributor
timestamp: September 29, 2024, 10:39:20 am
content: Thank you very much for reply!I purchased it 3 years ago and I occasionally used it until now But I found that it suddenly display very dim screen and a few days later It finally it displayed nothing...I plan to purchase OLED SSD1306 display in order to replace its broken display..But On the othere hands,I want to track down faulty components which cause broken display..https://www.reddit.com/r/AskElectronics/comments/r0fguj/new_quicko_t12942_display_off/But It seems that I should have been more cautious when I desoldered smd components especially smd components of many pins..By the way does it correctly work without display If I solder TC1014 or TC1015 or TC 1185 or LP5907 in the place of unknown component(It is written "601Km" on its surface and Its leg of pin3 was broken)?
What is proper soldering process for LFCSP-64 package? - Page 1
Forum section: electronics / beginners

author: radiolistener
author_rank: Super Contributor
timestamp: March 01, 2024, 10:47:34 am
content: I boughtradioberryboard on aliexpress, but the seller sent me broken device, it don't works. According to tests, unfortunately the root of cause is deadAD9866chip. It has clock on the input, but no clock on the output (both pin 19 and pin 61 are always zero) and there is no sign of life on its outputs.I'm thinking to try to repair it by replacingAD9866chip. But it looks not so easy. I never soldered such chips with a thermal pad on the bottom and don't know how to solder it properly. Could you please help?Does thermal pad should be soldered together with usual pins with heating, or it should be soldered later by putting some solder into through hole in PCB?What is the best way to desolder it and avoid damage and unsolder for other components?

author: JustMeHere
author_rank: Frequent Contributor
timestamp: March 02, 2024, 02:33:18 am
content: Hot air. Possibly a pre heater. Very steady hands. Possibly some chip quick. Google some videos

author: Jwillis
author_rank: Super Contributor
timestamp: March 02, 2024, 03:11:33 am
content: Found thisApplication NotePage 9 has some guidelines for rework.The data sheet for the AD9866 has a link to a application note on page 44 PCB DESIGN CONSIDERATIONS. But doesn't work. But I did find thishttps://amkor.com/document-library/?looking_for=lfcsp-64which might have more information.

author: Solder_Junkie
author_rank: Frequent Contributor
timestamp: March 02, 2024, 09:11:06 am
content: Do not use Chip Quik, not only won’t it help, it leaves a horrid alloy on the board that is hard to remove. I have used it on SMD boards but regretted it afterwards.Those ICs with underside heat transfer pads can be removed with hot air alone. The problem then becomes one of placing a replacement with high accuracy (and keeping it there) while you re-heat the board.Return the faulty board and buy from a reputable source. Or put it down to experience and throw it in the bin.SJ
What is remote cold switching? [The art of Electronics] - Page 1
Forum section: electronics / beginners

author: khatus
author_rank: Regular Contributor
timestamp: September 11, 2021, 02:24:22 pm
content: I can understand the meaning of the underlined sentences. Can anyone explain the whole meaning of this paragraph?What is the meaning ofsnake aroundhere??

author: FlexibleMammoth
author_rank: Regular Contributor
timestamp: September 11, 2021, 02:52:21 pm
content: I'd say its about using the transistor similar to a relay. You use a button or switch to apply a control voltage to the transistor, which turns it on and lets the signal pass.The inferior alternative is routing the signal directly over your front panel switch and turning it on and off this way. This is what they mean by "snaking around" (i.e. taking a long winding way from your wiring to the switch and back.

author: TimFox
author_rank: Super Contributor
timestamp: September 11, 2021, 06:32:57 pm
content: “Cold switching” means that the signal itself (low level, high frequency, whatever) stays back on the board, and that only DC voltage exists on the long cable to the panel switch.
What is resonant impedance? - Page 1
Forum section: electronics / beginners

author: chipwitch
author_rank: Frequent Contributor
timestamp: March 27, 2014, 03:55:51 pm
content: I bought some of these generic piezo elements on ebay.http://www.ebay.com/itm/121270884189?var=420233429010&ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649The specs at the bottom indicate "Resonant Impedance" at 200W? Google is showing a bunch of hits that I don't think is the same thing. The "watt" units was throwing me. I would think it should be Ohms?

author: Dago
author_rank: Frequent Contributor
timestamp: March 27, 2014, 04:25:49 pm
content: The omega symbol '?' often gets converted to 'W' due to re-encoding characters to a different encoding.

author: IanB
author_rank: Super Contributor
timestamp: March 27, 2014, 04:51:36 pm
content: The lower case Greek letter omega looks like a curly "w". Since the ohms symbol is an upper case omega, it sometimes happens that uppercase "W" is used to represent uppercase "Omega":It's a bit odd, since omega is really a letter "o", not a letter "w". But using uppercase "O" would lead to confusion with zero, so "W" is used to avoid that.

author: chipwitch
author_rank: Frequent Contributor
timestamp: March 27, 2014, 05:46:51 pm
content: Ah... yes.. now it makes perfect sense. Thank you.
What is RSC - Page 1
Forum section: electronics / beginners

author: queennikki1972
author_rank: Regular Contributor
timestamp: October 09, 2019, 12:23:21 pm
content: What is RSC ? I know its probably obvious but Im still new. Also at the bottom it says -10v Can someone explain a little further?

author: queennikki1972
author_rank: Regular Contributor
timestamp: October 09, 2019, 12:28:32 pm
content: Found it..https://www.eevblog.com/forum/beginners/question-on-resistor-label/

author: queennikki1972
author_rank: Regular Contributor
timestamp: October 09, 2019, 12:30:49 pm
content: But how do I calculate the sense resistor needed for the 0-30vdc supply in the diagram.

author: soldar
author_rank: Super Contributor
timestamp: October 09, 2019, 12:50:46 pm
content: Quote from: queennikki1972 on October 09, 2019, 12:30:49 pmThat resistor limits current. Nothing to do with voltage which is handled by the second LM317.Look at fig. 23.

author: queennikki1972
author_rank: Regular Contributor
timestamp: October 09, 2019, 02:03:12 pm
content: Ugh still lost..

author: RoGeorge
author_rank: Super Contributor
timestamp: October 09, 2019, 02:58:43 pm
content: In the datasheethttp://www.ti.com/lit/ds/symlink/lm317.pdf, figure 8.3.3 says how to calculate RscImax = 1.2/Rsc, so Rsc = 1.2/Imax. In your schematic Imax is 1.5A, so Rsc = 1.2V/1.5A = 0.8 ohms. The dissipated power for a 0.8 ohm resistor at 1.5A is P = I*I*R = 1.5A*1.5A*0.8ohm = 1.8WIn conclusion Rsc is 0.8/ 2W. A 2W resistor at least, 3W or more will be even better.Later edit:About the -10V, it's a negative voltage. To power that schematic, 2 voltages will be needed. One is +32...40V, the main power voltage. The other voltage is -10V, for the Q1 and Q2 biasing circuits. Q1 and Q2 are constant current generators, in order to get a constant current on each of their diodes pairs (D1, D2 and D3, D4 respectively) and thus a constant 1.2V on each pair of the series diodes.Both +32...40V and -10V are with respect to the GND (measured relative to the GrouND).The positive voltage will need to be able to provide at least 1.5A, while for the negative voltage there is not much need for a lot of current, a 0.1A maximum for the -10V will be more than enough.
What is step load current? - Page 1
Forum section: electronics / beginners

author: Artlav
author_rank: Frequent Contributor
timestamp: June 29, 2015, 06:36:42 pm
content: I was looking through the math for the two switch-forward converter (https://www.onsemi.com/pub/Collateral/AND8373-D.PDForhttps://www.onsemi.com/pub/Collateral/TND378-D.PDF), and they use something called "step load current" to calculate the output inductor value.The number is just given in the example solution as if i'm supposed to know it, yet it is never mentioned or defined before or after.What does it mean?The transformer primary peak current is proportional to the size of the output inductor, and yet it is derived from the size instead of the size being dictated by the primary peak current. So this step load current seems to be more important.

author: diyaudio
author_rank: Frequent Contributor
timestamp: June 29, 2015, 07:05:35 pm
content: Quote from: Artlav on June 29, 2015, 06:36:42 pmFigure 27. Step Load Response from 0.5 A to 5.5 A should be obvious.Its the load "steps" in increments as you can see 0.5 to 5.5A, in steps of 500mA per step.

author: PSR B1257
author_rank: Frequent Contributor
timestamp: June 29, 2015, 07:06:44 pm
content: QuoteAs the name impliesA current step from I1to I2(refere also to page 18)Therefore it is nothing more than a differential current, hence the Delta in the formula.It makes no difference whether you go from 0A to 5A or from 5A to 10A, the current difference is always the same.

author: Artlav
author_rank: Frequent Contributor
timestamp: June 29, 2015, 07:16:51 pm
content: Ok then...If i have a fixed load, does that mean that this is zero or near zero?If so, all their math ceases to work, with a filter size approaching infinity.What would be a good way to estimate the filter size in that case?

author: Jay_Diddy_B
author_rank: Super Contributor
timestamp: June 29, 2015, 07:41:42 pm
content: Hi,I described the circuit for doing these load current steps in this thread:https://www.eevblog.com/forum/projects/dynamic-electronic-load-project/msg288313/#msg288313For the purpose of design you should choose to step the load current from 50% to 100%, even if your load current doesn't step. Then size the output capacitor for around 3% change in voltage.The load step response is used to verify the stability of the control loop.Regards,Jay_Diddy_B

author: coppice
author_rank: Super Contributor
timestamp: June 30, 2015, 06:13:35 am
content: Quote from: Artlav on June 29, 2015, 07:16:51 pmA fixed load? Really? It never switches on or off? It can never fail and suddenly go from full load to zero? You might want to consider the impulse response of your design under all its operating conditions before you use the notion of a fixed load in your design.That said, good power supply design is all about achieving satisfactory impulse response, and a benign load makes the power supply designer's life very easy. Its often possible to treat sudden load disconnects as a special case, and arrange that the supply does an emergency shutdown, completely avoiding the need for continuous responsive control.
what is the alternative to this TRIAC - Page 1
Forum section: electronics / beginners

author: baltazar99
author_rank: Newbie
timestamp: July 19, 2021, 03:44:15 pm
content: Hi everyone,i am trying to implement a schematic fromhttps://content.instructables.com/ORIG/FHD/P461/J16P41I2/FHDP461J16P41I2.jpgthis requires a BTB26 triac -https://datasheetspdf.com/pdf-file/980785/STMicroelectronics/BTB26/1however i am having difficulties sourcing one and the very few that stock it charge a fair amount.Would someone be able to recommend an alternative, the input voltage is around 20v AC and will feed a soldering iron with 4amps current.Cheers

author: Terry Bites
author_rank: Super Contributor
timestamp: July 19, 2021, 04:39:35 pm
content: Given how ubiquitous this component is, why look for an alternative?That said, if it can handle the volts and amps it will do. They're not a fancy component.Double check the gate drive from your curcuit is enough to trigger the Triac. It usually is!What does 15 . 5 AC mean?I'd go by price. How about a BTA206X-800CT.https://www.ebay.co.uk/itm/184927957044?epid=2103086742&hash=item2b0e90b034:g:i~sAAOSwtOZci4EqPut an RC snubber on it anyway. 100n/>30v in series with 100R across the triac. Stops EMC and false triggering.
What is the ambient temperature limit for typical passive scope probes?  - Page 1
Forum section: electronics / beginners

author: Jim from Chicago
author_rank: Regular Contributor
timestamp: November 08, 2023, 06:29:51 pm
content: We often test things in a temp chamber at my job, and we often stick scope probes in the temp chamber because we don't want a huge ground loop formed by running long wires out of the chamber. The highest we go is about 80C and the lowest is about -30C.Are we reducing the lifetime of the probes?Are we compromising the measurement performance of the probes?Is there a number you use as a strict limit in terms of ambient temperature exposure for probes?

author: ataradov
author_rank: Super Contributor
timestamp: November 08, 2023, 06:49:04 pm
content: Probe manuals should have this information.For example, Tek P2221 has this:Operating: 0 °C (+32 °F) - +50 °C (+122 °F)Nonoperating:–55 °C to +75 °C (–67 °F to +167 °F)And TPP1000:Operating: –15 °C to +65 °C (+5 °F to +149 °F)Nonoperating: –62 °C to +85 °C (–80 °F to +185 °F)There are also limits on humidity.But in practice, I've used them in the full -40 - 125 C range and they seem to do just fine. But if you are making characterization measurements, don't use equipment outside of its specs, of course.

author: CaptDon
author_rank: Super Contributor
timestamp: November 08, 2023, 11:18:49 pm
content: I can confirm what Ataradov has found. We test the locomotive ECU circuit prototypes at -40C to +100C and it hasn't been detrimental to the probes. As stated however, humidity can be a problem. Most of our chambers use dry nitrogen gas for cooling / purging the chamber and expels the humidity (being careful to not open the door until at or above room temperature. We have some two stage closed loop refrigerant cooled chambers and they are a pain in the ass when it comes to humidity contamination although that can be a good thing for testing conformally coated boards.

author: David Hess
author_rank: Super Contributor
timestamp: November 11, 2023, 01:53:41 am
content: Tektronix used to make special probes with extended temperature ranges, however the major difference was being specified for accuracy over an extended temperature range.

author: tooki
author_rank: Super Contributor
timestamp: November 11, 2023, 09:07:54 am
content: Quote from: Jim from Chicago on November 08, 2023, 06:29:51 pmThe question in the title you could have answered yourself by looking at some probe datasheets.Using any probe outside of its specified conditions means your measurements are no longer guaranteed.PMK, the German probe manufacturer that supplies many of the high-end probes for the major scope manufacturers, makes special extended-temperature probes specifically for use in environmental test chambers:http://www.pmk.de/en/products/tastkoepfe_fuer_umweltpruefungenAlso, depending on your circuit, another option may be to use coaxial cables to your DUT. I’ve worked on a few projects that use RG-196 coax (same dimensions and performance as RG-178, but with both the dielectric and jacket made of teflon) at cryogenic temperatures.
What is the best approach to control the resistance in my LM338 Laser Driver? - Page 1
Forum section: electronics / beginners

author: acone
author_rank: Newbie
timestamp: May 20, 2025, 10:49:19 am
content: Hey everyone!I have a little laser project going on, for which I have a 850nm (IR) Diode that claims to be doing 2.3W.(https://de.aliexpress.com/item/1005006808596966.html?gatewayAdapt=glo2deu)Now, the Datasheet, however trustworthy that might be, claims 1.7V to 2.2V and 2.5A to 3.6A.Since my existing LM317s and LM337 wouldn't have had enough juice, I ordered a bunch of LM338s. Now, I calculated that I'd need something between 0.5Ω and 0.42Ω to get the desired Amperage from the LM338.All the resistor kits I have are 1/4W or 1W at best, lowest value is 1Ω.What would be your approach?Combine a bunch of 1W resistors in parallel?Would you try to get some high power potentiometers?Looking forward to your input!(And don't worry, I have laser safety goggles rated appropriately for the diode, my adjustable PSU is rated 3V-24V, 3A)

author: Ian.M
author_rank: Super Contributor
timestamp: May 20, 2025, 01:16:05 pm
content: Allowing for tolerances, and assuming you have enough headroom to tolerate an additional 1.5V of voltage drop, a 0.39 ohm 5W resistor connected to Out, feeding a 0.15 ohm 2W resistor to the load with a 100 ohm pot across the 0.15 ohm resistor, wiper to Adj, would give you adjustability in the range 2.3 - 3.2 A load current.