hybridfree/eevblog-posts huggingface dataset:
bluetooth remote mod for sony camera - Page 1
Forum section: electronics / beginners

author: jamskof
author_rank: Newbie
timestamp: May 22, 2023, 07:36:41 am
content: hi guys, firstly, bare with me, i know NOTHING about electronics! i am merely a creative person!a bit of background of the slider and how it works.. i will try to be brief..timelapse sliders like the one below that i want to purchase, even though this slider is bluetooth enbabled, it HAS to connect to the camera via a shutter release cable. the sony ones used to have what the called a multiport socket, which looked identical to micro usb. different camera brands do have different sockets, some proprietery.https://au.neewer.com/collections/slider/products/neewer-31-5-80cm-39-4-100cm-motorized-camera-slider-66600616the idea is, for timelapses, via the slider app on your phone, you can select interval between shots and exposure length, and no. of photos. i.e. 1 second exposure, 250 shots, and take 1 hour to get from the far left to far right of slider.. once activated the slider will move eg. 10mm, then the camera will take the picture, wait for the full exposure, and say a second later, the camera will move again etc etc..the camera has a usb-c port.. sony say "its possible" to control via this port.. but they dont support it, but in theory a third party could create it.. problem is, nobody is. many people have tested with wired intervalometers using usbc adapters but with no luck..SO! .. there seems to be only one solution out there on the interwebs.. its a bluetooth shutter release thats compatible with the camera.. open the module up and somehow insert something like a 2.5mm jack connected to the module.. this guy is the only person thats doing it.https://gethypoxic.com/collections/camera-switches-and-adapters/products/sony-camera-bluetooth-to-2-5mm-adapter?contact_posted=true&variant=37968267346102so the idea is, you connect the phone to the slider.. then the slider connects to the bluetooth module i think via 2.5mm jack on each end, then the module triggers the camera via bluetooth.id like to support the guy selling these but its just out of my price range and the whole thing might not be reliable for what i need it for, i dont live in the u.s. and shipping prices are high too.AND SO.. my big question is.. does this sound like a complicated mod?, if any of this makes any sense to anyone out there.. is this something a complete novice or am i very much out of my depth here? or is this impossible to even guess without seeing the inside of the jjc remote?thanks so much in advance!
Intoroduce a reliable global online shop - Page 1
Forum section: electronics / beginners

author: Hidian
author_rank: Newbie
timestamp: January 25, 2017, 07:41:48 pm
content: Hello daveCan you introduce a reliable global online shop for electronic components?Unfortunately shops like digikey are not available for our country.

author: Benta
author_rank: Super Contributor
timestamp: January 25, 2017, 09:35:03 pm
content: I don't think you'll find one. AFAIK, your country is still on the nono list, at least to a certain extent.No shop would risk their company in that situation.

author: Jeroen3
author_rank: Super Contributor
timestamp: January 26, 2017, 06:41:27 am
content: Can confirm. We immediately got a call, and a visit soon after, when we received payment (€1k) from Iran for a product. We were not allowed to ship to Iran.
Introduce yourself - Page 1
Forum section: electronics / beginners

author: Justin_
author_rank: Newbie
timestamp: March 31, 2015, 09:00:08 am
content: Hello I was thinking about how most forums have a thread to tell the forum members about yourself, your story, or just whatever when you join the forum and thought I would start one.If this is a problem or something the mods can take it down.My name Is Justin I have been part of the chat for about 1 year now and I am just joining the forum. I live in a town of ~110,000 people (Missoula MT USA). I first picked up a soldering iron to make an altoids tin audio amp for a in car DVD player at about 10 years old, but long before that at 3 years old is when I first disassembled something to learn how it worked, then at about 5 or 6 years old I got into computers taking the old ones Tearing them apart to find out how they work, then I moved into the software end messing around with the settings to se what happens, along with the computers I took apart TV's VCR's vinyl players, and just about anything I could get my hands on. I started wanting to make electronic things an like most of us I started with the 100 in one kits and worked my way forward. I have made remote fireworks ignition systems, In car entertainment systems with a 17" computer monitor, wii, xbox360, dvd player, vcr, also my own computer controlled light display with an FM transmitter, and lots of other stuff. This has all lead me to want to learn more, dig deeper into how stuff works. I will soon be wanting to get better test equipment and such and thought this would be a good time to Join the forum.I now have a job as a computer tech so if you have a question feel free to ask. I also am a main person in a local to Missoula (for now) program named Laptops For Students (relaptops.org) We take in old or unwanted laptops, fix them up, put an OS and a Microsoft Office compatible program on them, and give them away for free to local studentsI can code in HTML (website code) but not anything elsebut looking to change that.That is most of my story I guess.Justin_P.S. My spelling SUCKS (YAY spellcheck)

author: Chipmunk
author_rank: Contributor
timestamp: March 31, 2015, 09:14:17 am
content: Hi Justin, good to meet you! Everyone seems to have built SOMETHING into an altoids tin at some stage or other.Incidentally there's an official 'introduce yourself' sticky thread here:https://www.eevblog.com/forum/chat/new-member-please-introduce-yourself/I'm sure a mod will pop along to shift the post eventuallyI got into electronics in the 70s thanks to my dad letting me burn mys...I mean do the soldering on our newfangled electronic doorbell

author: Justin_
author_rank: Newbie
timestamp: March 31, 2015, 09:16:37 am
content: O Thanks for telling me I will move the text there
Introduction - Page 1
Forum section: electronics / beginners

author: T49Rick
author_rank: Newbie
timestamp: January 12, 2022, 05:55:03 pm
content: Hello EEVBlog Forum.I am Rick, a retired resident of Southern California, USA.Even though I am a complete amateur regarding electronics and electrical wiring in general, I have experience in home construction and handyman-type home repairs and my previous pre-retirement employment in the fire service.I apologize in advance for any posting etiquette errors and promise to get better with your coaching.I am looking forward to learning the science and practical application from the experts here on the forum.

author: rpiloverbd
author_rank: Regular Contributor
timestamp: January 14, 2022, 08:35:16 am
content: Nice to meet you.
Introduction and first thoughts/question. - Page 1
Forum section: electronics / beginners

author: David Hobson
author_rank: Newbie
timestamp: November 08, 2014, 04:31:41 am
content: Hello EEVblog!I am new to the Forum and am looking forward to learning, and sharing what I may learn.For years now I have collected analog musical instruments. I have done some simple mechanical & electrical repair work on my own gear since 1997 or so.I am going to be taking a 'tech mentoring' course this winter to educate myself in preparation for what seems could be a logical career in electronics repair.I have enjoyed and learned from the YouTube videos posted by Dave...thanks Dave.I have purchased a decent DMM (an Extech EX520 I got a good deal on) and most hand tools I will require for basic repair work.I already own an old Tektronix 465 scope, and boxes of various test leads, probes, wire, etc. But I still need to purchase some of the more expensive equipment.Right now I am curious what type of variable power supply 'KIT' I should purchase. I mean, what is the best value for a PS Kit, on ebay perhaps, that would be a good first project?I will be using what I learn to repair analog synthesizers at first, and then move on to wherever my brain will allow me to move.Any other advice would be of great value. But of course, right now, I am building up my stock of equipment.Thank you.

author: Paul Price
author_rank: Super Contributor
timestamp: November 08, 2014, 07:01:58 am
content: Use a power supply from one of the dead synthesizers. Search forum for LM317 or for "Power Supply".https://www.eevblog.com/forum/projects/bench-power-supply-0v-~-15v-cccv/msg264407/#msg264407
Introduction to Electronics course  - free - Aug 22 2016 ---- Not for beginners - Page 1
Forum section: electronics / beginners

author: ez24
author_rank: Super Contributor
timestamp: August 22, 2016, 08:07:40 pm
content: FYIhttps://www.coursera.org/learn/electronics#Free or $50 for a certEdit: this is not a beginners course (strange title)They have some interesting resources and what really has me interested is this statement:"Use your Coursera Intro to Electronics email as student verification."I am now trying to figure out how to do this, there is something I want with a good student discount.
Introduction to Operational Amplifiers with LTSpice - Page 1
Forum section: electronics / beginners

author: HoracioDos
author_rank: Frequent Contributor
timestamp: April 27, 2017, 03:55:35 pm
content: For those who might be interested in Op-Amp basics like me.https://learn.sparkfun.com/tutorials/introduction-to-operational-amplifiers-with-ltspice
Introduction to switching voltage regulators? - Page 1
Forum section: electronics / beginners

author: Spike101
author_rank: Contributor
timestamp: August 03, 2015, 10:54:15 am
content: Hi,In my recent projects i often had to use voltage regulators that can output some higher current, and most of the time i just used what the TI Webench spit out. But I'd really like to know how these things actually work, so i can design the circuits by myself or at least know what's going on if something doesn't work as expected.I know the basic principle of buck regulators, but the more complex switching regulators need a high-side and a low-side mosfet. The recent one i used has a CBOOT pin which is a "High side bootstrap connection". I don't even know what that means.. Also it's possible to select the switching frequency, synchronize them up etc..Can you recommend some resources where I can learn more about the features and working principle of more advanced switching regulators (something a bit more beginner-friendly than the actual datasheet...)?

author: EEVblog
author_rank: Unknown
timestamp: August 03, 2015, 11:13:41 am
content: Try this video to see just how similar switchmode and linear regulators are:

author: Spike101
author_rank: Contributor
timestamp: August 03, 2015, 12:48:51 pm
content: Thanks, great video.But why do some switchmode regulator ICs require two external mosfets (high-side and low-side) instead of one transistor? Just for efficiency? Or does it have better characteristics for the output voltage?

author: CoolBeer
author_rank: Newbie
timestamp: August 03, 2015, 01:56:07 pm
content: The ones with high and low side mosfets use the low side one to replace the diode for better efficiency. It's a bit more complex to drive though.

author: Spike101
author_rank: Contributor
timestamp: August 03, 2015, 02:46:36 pm
content: Quote from: CoolBeer on August 03, 2015, 01:56:07 pmAh i see - Thanks, it starts to make some sense...
Inverse of dead band observed in PWM, STM8S003F3 - Page 1
Forum section: electronics / beginners

author: Vindhyachal.takniki
author_rank: Frequent Contributor
timestamp: May 10, 2020, 02:04:48 pm
content: 1. I have written below code for PWM generation for STM8S003F3. Two pwm pins are used inverted with dead time.2. But I observed this graph on CRO of two pins is this. I was expecting one pin to turn off before another turn on i.e deabband.. But reverse is happening here.More I increase deadband it has reverse effect. What I am doing wrong here?Code:void all_tasks_manager(void){uint8_t key;uint8_t start = 0U;float32_t arr,ccr,y;uint16_t temp1,temp2;g_segment_display = 0U;SEG_1_DISABLE();SEG_2_DISABLE();segment_register_update(5); // display htg_segment_display = 1U;/* TIM1 Peripheral Configuration */TIM1_DeInit();/* Time Base configurationTIM1_Prescaler = 0TIM1_CounterMode = TIM1_COUNTERMODE_UPTIM1_Period = 65535TIM1_RepetitionCounter = 0*/TIM1_TimeBaseInit(0, TIM1_COUNTERMODE_UP, 1067,0);/* Channel 1, 2 and 3 Configuration in PWM mode *//*?TIM1_OCMode = TIM1_OCMODE_PWM2TIM1_OutputState = TIM1_OUTPUTSTATE_ENABLETIM1_OutputNState = TIM1_OUTPUTNSTATE_ENABLETIM1_Pulse = CCR1_ValTIM1_OCPolarity = TIM1_OCPOLARITY_LOWTIM1_OCNPolarity = TIM1_OCNPOLARITY_LOWTIM1_OCIdleState = TIM1_OCIDLESTATE_SETTIM1_OCNIdleState = TIM1_OCIDLESTATE_RESET*/TIM1_OC1Init(TIM1_OCMODE_PWM2, TIM1_OUTPUTSTATE_ENABLE, TIM1_OUTPUTNSTATE_ENABLE,CCR1_Val, TIM1_OCPOLARITY_LOW, TIM1_OCNPOLARITY_LOW, TIM1_OCIDLESTATE_RESET,TIM1_OCNIDLESTATE_RESET);/* Automatic Output enable, Break, dead time and lock configuration *//*TIM1_OSSIState = TIM1_OSSISTATE_ENABLETIM1_LockLevel = TIM1_LOCKLEVEL_1TIM1_DeadTime = 117TIM1_Break = TIM1_BREAK_ENABLETIM1_BreakPolarity = TIM1_BREAKPOLARITY_HIGHTIM1_AutomaticOutput = TIM1_AUTOMATICOUTPUT_ENABLE*/TIM1_BDTRConfig( TIM1_OSSISTATE_DISABLE, TIM1_LOCKLEVEL_OFF, 5, TIM1_BREAK_ENABLE,TIM1_BREAKPOLARITY_HIGH, TIM1_AUTOMATICOUTPUT_ENABLE);/* TIM1 counter enable */TIM1_Cmd(ENABLE);/* Main Output Enable */TIM1_CtrlPWMOutputs(DISABLE);TIM1_Cmd(DISABLE);temp1 = (uint16_t)851;temp2 = (uint16_t)425;TIM1->CCR1H = (uint8_t)(temp2 >> 8);TIM1->CCR1L = (uint8_t)(temp2);TIM1->ARRH = (uint8_t)(temp1 >> 8);TIM1->ARRL = (uint8_t)(temp1);TIM1_CtrlPWMOutputs(ENABLE);TIM1_Cmd(ENABLE);while(1){}}

author: Siwastaja
author_rank: Super Contributor
timestamp: May 10, 2020, 02:32:53 pm
content: If "TIM1_OCPOLARITY_LOW" means configuring the pin polarity as "active-low", then this means everything is working as it should: the signals are "on" at 0V, "off" at 5V, and you have the proper dead bands.If you need active-high polarity instead, change this setting.

author: Vindhyachal.takniki
author_rank: Frequent Contributor
timestamp: May 11, 2020, 02:31:44 pm
content: Meaning I have to change this:TIM1_OCPolarity = TIM1_OCPOLARITY_LOWTIM1_OCNPolarity = TIM1_OCNPOLARITY_LOWto:TIM1_OCPolarity = TIM1_OCPOLARITY_HIGHTIM1_OCNPolarity = TIM1_OCNPOLARITY_HIGHWill check tomorrow in actual setup.
Inverted LCD backlighting? - Page 1
Forum section: electronics / beginners

author: RyuKojiro
author_rank: Newbie
timestamp: March 19, 2017, 02:34:26 am
content: I thought I had a good enough understanding of LCD backlight technology (there's a light and a matte in the back, and the LCD can block that flat light in order to produce a dark area). However, I've always been under the impression that devices which instead light up areas just had an opaque substance blocking the areas intended to always be dark, and instead drew the liquid crystal away from pixels/segments in order to light an area.I recently found these pictures of an HP 3478A with a backlight "upgrade" that does inverted lighting, but I don't understand how that could work. I highly doubt they are making their own HP 3478A compatible LCDs. So, how are they doing this inverted style of backlighting? I'm assuming my previous understanding was wrong/incomplete, and I'd love to know how to do this myself!

author: MrBungle
author_rank: Unknown
timestamp: March 19, 2017, 04:18:11 am
content: It is done with the polarising filters.Back in the late 80's when I was in high school there was a brand of calculator(I think Casio, but could've been Sharp) that had loose polarising filters (today they are typicaly adhered to the glass) and one could easily swap the front and back filters to reverse the display.
Inverted Output Enable - Page 1
Forum section: electronics / beginners

author: insurgent
author_rank: Regular Contributor
timestamp: April 18, 2011, 03:12:52 am
content: Hi All,I've noticed that IC's with an "output enable" pin of some kind are often inverted (1 = disabled, 0 = enabled). I was curious as to whether there is some historical or technical reasoning behind this.Take care,John

author: Zad
author_rank: Super Contributor
timestamp: April 18, 2011, 03:20:17 pm
content: It always puzzled me too, I guess it is because they are easy to drive with open-collector outputs.

author: Mechatrommer
author_rank: Super Contributor
timestamp: April 18, 2011, 09:59:16 pm
content: imo the software IDE is made by the hardware guy, they are not good at encapsulating things, no offense!

author: Psi
author_rank: Super Contributor
timestamp: April 19, 2011, 02:26:39 am
content: it may have something to do with driving the IC's on a system bus, but i'm not sure how exactly.

author: logictom
author_rank: Unknown
timestamp: April 19, 2011, 12:28:41 pm
content: We were taught that it's to do with/came from when a system isn't functioning or loses power, you can detect that a high has gone low when it's not working/loses power but if it's already low then it's undetectable. In general for active low, not specifically for CS/OE.That's a pretty crap explanation but I'm sure you can get the jist

author: scrat
author_rank: Frequent Contributor
timestamp: April 19, 2011, 01:02:28 pm
content: Quote from: logictom on April 19, 2011, 12:28:41 pmThis can be also reversed if you think of safety issues, where you don't want a controlled IC to work if the controller isn't powered up...It still is a strange thing

author: FreeThinker
author_rank: Frequent Contributor
timestamp: April 19, 2011, 01:04:22 pm
content: I Think it's a 'fail to safety' type of thing. Unconnected gates will tend to float high and most fail conditions will produce a non zero voltage of some sort. Also driving a pin low is a more positive act than driving one high (noise etc).

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: April 19, 2011, 01:22:27 pm
content: The convention of active-low selects and enables dates back to the days of RTL and TTL in the early 1970's or maybe a little earlier. These early logic families pulled low harder and faster than they pulled high, and the input structure would go high if unconnected.

author: insurgent
author_rank: Regular Contributor
timestamp: April 20, 2011, 11:56:45 pm
content: Thanks guys,The safety/failsafe & older electronic family reasons definitely makes sense.
Inverter air conditioner - Page 1
Forum section: electronics / beginners

author: huu_tri0101
author_rank: Contributor
timestamp: December 06, 2014, 04:47:20 pm
content: Please tell me what the function of Q404 and the name of "CT", what is it?Thank you guys a lot

author: IanB
author_rank: Super Contributor
timestamp: December 06, 2014, 05:07:33 pm
content: Q404 looks like it regulates current through the reactor in some fashion. (Diode bridge DB02 causes Q404 to see DC rather than AC.)The device "CT" looks like it might be a current transformer.

author: BennVenn
author_rank: Regular Contributor
timestamp: December 08, 2014, 12:52:20 am
content: Its been a while, looks like it could be a hydraulic symbol?

author: Riotpack
author_rank: Regular Contributor
timestamp: December 08, 2014, 01:19:31 am
content: Is it some form of power factor correction??

author: flolic
author_rank: Frequent Contributor
timestamp: December 08, 2014, 01:22:17 am
content: CT is current transformer, and Q404/DB02 is part of PFC circuit.

author: huu_tri0101
author_rank: Contributor
timestamp: December 08, 2014, 06:41:17 am
content: Quote from: flolic on December 08, 2014, 01:22:17 amSo it a active PFC ?Thank you

author: flolic
author_rank: Frequent Contributor
timestamp: December 09, 2014, 09:31:54 am
content: Yes.
inverter chip not inverting - Page 1
Forum section: electronics / beginners

author: ravener96
author_rank: Newbie
timestamp: July 23, 2018, 09:29:59 pm
content: i got myself a toolkit of logic chips for a project i'm working on, and thought i'd test a few out to be sure they work like they should.unfortunately a 74ch05n inverter chip doesent seem to be cooperating.as per the datasheet i have an LED with a resistor connected to positive on the output, but the led is on with the input high and off with the input low. it's effectively a repeater at this point.am i just being dumb? the outputs are open drain, and i might just be misunderstanding what it implies, i just assume logical high is the pin being open to ground, and low being closed.in the attached picture i have the same circuit (i couldent figure out how to get the LED icon the right way, and the chip name is wrong) in this example the LED is on.

author: ravener96
author_rank: Newbie
timestamp: July 23, 2018, 09:34:56 pm
content: i might have worded it strangely, it's not A chip not working. i have tested a few and they ALL work the same. sorry for confusion

author: ravener96
author_rank: Newbie
timestamp: July 23, 2018, 09:39:12 pm
content: read the texthttp://www.ti.com/lit/ds/symlink/sn74hc05.pdf

author: rstofer
author_rank: Super Contributor
timestamp: July 23, 2018, 09:39:48 pm
content: It seems correct to me, if I understand what you are saying.With the LED connected to Vcc, a Gnd or 0V is required to turn it on. The output of an inverter will be 0V when the input is high.So, logic '1' on the input should turn the LED on. Logic '0' should turn it off.

author: ravener96
author_rank: Newbie
timestamp: July 23, 2018, 09:46:20 pm
content: i guess it makes sense, i could just be misunderstanding how it would interact with other logic gates.

author: ravener96
author_rank: Newbie
timestamp: July 23, 2018, 10:07:07 pm
content: thanks a lot guys, i just tried connecting it up to an and gate with a few pullup resistors, and it works swimmingly. most of the time the problem is between the keycaps and the chair

author: rstofer
author_rank: Super Contributor
timestamp: July 23, 2018, 10:59:31 pm
content: The thing about LEDs in general is that we need to pull them down because, in the old days, TTL could pull down a lot more than it could pull up.Given that we pull down to turn on, it is kind of backwards to how we view logic. In fact, there is an entire way of thinking about negative true logic.With the inverter things are easy to understand: Logic '1' to turn the LED on, logic '0' to turn the LED off. Wired the same way to an Arduino output (pull down configuration), the logic is upside down. Logic '0' to turn the LED on, logic '1' to turn the LED off.It all works out...
Inverter DC bus fuse protection - Page 1
Forum section: electronics / beginners

author: mike buba
author_rank: Contributor
timestamp: October 14, 2024, 09:04:02 pm
content: Hi all,I am in the process of designing a PCB three-phase inverter, 5 kW, with Vin= 700 V and Vout (line-to-line)= 400 V. I read it is recommended to put a fuse in each pole (DC+ and DC-rail).There is also a recommendation to use fast-acting semiconductor fuses (e.g., gR), which have much faster reaction times compared to fast-acting fuses.The only fuse I could find matching my requirements (i.e., DC voltage: 1000 V, rated current: 12 A, gR) is SIBA Fuses 5021706.12. There are Bussmann/Eaton PV-12A10-T and Phoenix Contact 3062781, but they are gPV fuses for photovoltaic applications. However, all the fuses are out of stock. The only one available in this range is Schurter 0090.1012; however, it is also gPV and not gR.Considering I find it hard to find an appropriate fuse, do I need a DC bus fuse protection? ... Are there any other fuse types to consider or any other protection methods I could use?

author: coppercone2
author_rank: Super Contributor
timestamp: October 14, 2024, 10:25:19 pm
content: I mean it all depends on your load.The faster acting the fuse, the more likely its not to start a motor fire .Ever see a 5kW motor go up? I smoked a 400W motor and wow it makes alot of smoke FASTSmoke condition is a under statementI would imagine that this is kind of like how you get a return customer. If it blows the fuck up, they might not buy another one even if its part of a machine that is expenisve, because safety will notice it. If it calmly burns out, it might get bought over and over again because it did not scare anyone, the budgets are usually nice.Nothing gets fixed quicker then a safety issue.I think you should work on making a good relationship with the customerI would say its worth buying whatever will prevent smoke from forming, because smoke = investigation. Broken device might be a small budget request. Its also something you can advertise, i.e. "this device is designed not to explode and cause a incident".
Inverting a signal - Page 1
Forum section: electronics / beginners

author: aaron
author_rank: Regular Contributor
timestamp: April 16, 2013, 01:13:41 pm
content: Ok, this is probably the biggest 'noob' question of the day.I basically want to light up an LED, when another LED is off, to put it simply.I wanted to build a simple circuit that lit an LED when it's dark. I didn't have any LSR's, so I hooked a tiny tiny solar panel which gives around .5 volts in sunlight, up onto an op-amp which drives an LED at around 3 volts at .5v input. Obviously this is the wrong way around, I've been messing with transistors and stuff for ages. I think the hardest part to learn with all of this is pull down and pull up resistors and the formulas, I'm probably missing something obvious.But yeah, I just want a positive output signal when the current setup led is low.Thanks in advance guys

author: jpb
author_rank: Super Contributor
timestamp: April 16, 2013, 01:44:07 pm
content: To switch you probably want to use a comparator rather than an op amp (i.e. an op amp designed to go into saturation). But if you want to dim the led with light, have you tried just biasing it on and applying your output voltage to the other end of the diode to reduce the voltage across it? So you have +3V - series resistor to limit current - diode - other resistor acting as load for op-amp - ground. I'm not a great expert - you might be able to just use one resistor but I'm not sure what the output impedance of the op-amp looks like. I would just experiment.

author: darko31
author_rank: Regular Contributor
timestamp: April 16, 2013, 02:09:38 pm
content: Could you use transistor as inverter for the other LED?

author: smashedProton
author_rank: Frequent Contributor
timestamp: April 16, 2013, 02:39:45 pm
content: Easy! 2 led goes between the output and ground. The other goes between 5v and your output
Inverting Comparator (Help)  - Page 1
Forum section: electronics / beginners

author: Delta920
author_rank: Newbie
timestamp: January 17, 2022, 09:47:09 am
content: Hi, I am revising for my upcoming Exam and this is one of the revision question that I don't know how to proceed. Please help

author: oPossum
author_rank: Super Contributor
timestamp: January 17, 2022, 09:57:16 am
content: Study section 7.7 and 8.2https://www.ti.com/lit/ds/symlink/lm339.pdf

author: rob77
author_rank: Super Contributor
timestamp: January 17, 2022, 10:08:37 am
content: hint:a) has to do something with common mode input and open collector output.b) once you answer "a" you will know how to rectify the circuit.
I/O RTU module and 3 phase contactor - Page 1
Forum section: electronics / beginners

author: Remark
author_rank: Contributor
timestamp: October 12, 2023, 08:01:13 pm
content: Hello everyone,Is it possible to somehow combine I/O RTU module (DIO-M-R2 series) with 3 phase contactor (let's say lc1d25) to switch it on or off? Or maybe is there any other options to control contactor remotely?Thanks for the answers.

author: themadhippy
author_rank: Super Contributor
timestamp: October 12, 2023, 08:24:18 pm
content: if the contactor is only to be controlled by the module then just use one of the RTU module relay outputs to switch the contactors coil.
IOGEAR GUH326 USB 3.0 Hub – Overvoltage Damage Diagnosis Help - Page 1
Forum section: electronics / beginners

author: vladc77
author_rank: Regular Contributor
timestamp: June 25, 2025, 06:24:39 pm
content: Hi all,I’m trying to recover an IOGEAR GUH326 6-Port SuperSpeed USB 3.0 Hub after accidentally connecting a 12V power supply instead of the required 5V. The hub no longer powers up.I opened it up and didn’t see any visibly burnt or damaged components. The 5V power supply outputs voltage, but nothing comes through two components highlighted in the red box in the attached image.Does anyone recognize these components or have any idea what might have failed in this case? I’d really like to attempt a repair if possible. Any guidance would be appreciated!Thanks in advance.

author: wraper
author_rank: Unknown
timestamp: June 25, 2025, 06:33:35 pm
content: These are 0 ohm (jumper) resistors apparently used like fuses.QuoteQuite unlikely that none of the 4 ICs failed, but not necessarily all of them. Some may have failed earlier and protected the rest by shorting the power rail.

author: vladc77
author_rank: Regular Contributor
timestamp: June 26, 2025, 02:01:59 am
content: Thank you for explaining the possible consequences. If any of the ICs have failed, then it probably isn’t worth trying to repair it. That’s unfortunate. I had assumed the fuses were there to prevent this kind of damage
Ion Fan - Page 1
Forum section: electronics / beginners

author: huu_tri0101
author_rank: Contributor
timestamp: March 06, 2013, 06:14:40 pm
content: what does ion fan do ? what benefits in electronic field ? how does it affect health ?

author: Analogtech
author_rank: Contributor
timestamp: March 06, 2013, 07:06:47 pm
content: An ion fan is a type of fan that uses high voltage ion winds to cool things down and its main advantage is its relaiability compared to a traditional fan but if you want a large flow rate you would be better off using a regular fan and i dont think it has any health advantages or disadvantages
IOS + Swift + Firebase Question  - Page 1
Forum section: electronics / beginners

author: Karamel
author_rank: Regular Contributor
timestamp: July 28, 2017, 12:18:37 am
content: Hi everyone,I know you think that it is weird when you see the title in Electronic forum. However, I am electrical and electronics engineering student and I am, unfortunately, dealing with IOS programing. I must read data from Firebase cloud database storage. Let's see what I did.I created JSON database tree and I can read specific values with these codes. I can see on table view "Albert Einstein"Code:ref.child("Personel").child("Name").observeSingleEvent(of: .value, with: { (snapshot) inif let item = snapshot.value as? String{self.myList.append(item)self.LessonsTableView.reloadData()}})But, I want to see which categories under Personal column? Like this,Is there any way to get or learn which columns are under "Personal"P.s: Table view output must be -> Age, Name, Photo

author: sokoloff
author_rank: Super Contributor
timestamp: July 28, 2017, 11:56:25 am
content: It seems like your questions is a straight JSON handling in Swift question.See here:https://developer.apple.com/swift/blog/?id=37In particular:Code:for (key, value) in ref {// access all key / value pairs in dictionary (which is called "ref" in your code snippet)}

author: Karamel
author_rank: Regular Contributor
timestamp: July 28, 2017, 07:20:40 pm
content: All examples,They know "Age", "Name" or "Photo" and they reach their values. But think that, I don't know "Age". It could be "AGE", "Age:", "Age=" something like theses.I just want to look at under of "Personel" with programmatically and I must find "Age", "Name" and "Photo". Just these, not their values.

author: sokoloff
author_rank: Super Contributor
timestamp: July 28, 2017, 09:05:19 pm
content: That's what the "for (key, value) in ref" is for.See below for a more digested answer:Code:let jsonObject: [String: [String:Any]] = ["Personel": ["age": 27,"name": "Albert Einstein","picture": "whatever..."]]print("\nHere's all the data (for a set depth tree)")for (key, value) in jsonObject {print("Key:\(key)")for (innerkey, innervalue) in value {print("\(key)->\(innerkey):\(innervalue)")}}print("\nHere's exactly what you're asking for I think")for (key, value) in jsonObject {//print("Key:\(key)")for (innerkey, innervalue) in value {print("\(innerkey)")}}

author: sokoloff
author_rank: Super Contributor
timestamp: July 28, 2017, 09:08:01 pm
content: Or, if you only want to dive into keys that are "Personel" then:Code:let jsonObject: [String: [String:Any]] = ["Personel": ["age": 27,"name": "Albert Einstein","picture": "whatever..."]]print("\nHere's all the data (for a set depth tree)")for (key, value) in jsonObject {print("Key:\(key)")for (innerkey, innervalue) in value {print("\(key)->\(innerkey):\(innervalue)")}}print("\nHere's exactly what you're asking for I think")for (key, value) in jsonObject {//print("Key:\(key)")if (key == "Personel") {for (innerkey, innervalue) in value {print("\(innerkey)")}}}
Iosolated voltage detection - Page 1
Forum section: electronics / beginners

author: nemo000111
author_rank: Contributor
timestamp: March 27, 2014, 02:29:59 pm
content: I've got a standard red led and I need an electrically isolated way of seeing if there is voltage on the traces for the led. Using a light sensitve component isn't an option. This also needs to have low enough current requirents that the led can still function without changing its resistor. This dectection would happen after the resistor. This is part of a detection circuit to see if the device is on or not, so I just need a boolean voltage or no voltage (not how many volts there is). I was thinking an opto coupler as a relay (and flyback diode) might be too much. All ideas welcome. Thanks.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: March 27, 2014, 02:34:21 pm
content: I was also thinking optoisolator.

author: nemo000111
author_rank: Contributor
timestamp: March 27, 2014, 03:14:12 pm
content: Thanks. Since I don't care about data transfer speed, what specs would I look for to make this work? Lowest current draw and same voltage?

author: T3sl4co1l
author_rank: Super Contributor
timestamp: March 27, 2014, 03:44:03 pm
content: What is the LED supplied by? How much V, I is available? What series resistance?What are you detecting it with? What are you switching, if anything? Is it logic level?Bog-standard optos start with 4N35 (and the simplified 4-pin equivalents) and go up from there in various directions.Tim

author: Smokey
author_rank: Super Contributor
timestamp: March 27, 2014, 09:03:58 pm
content: Opto in series with the LED is easy and cheap.Check out PC357http://www.sharpsma.com/webfm_send/1079Digikey has a TON of similar devices.
IP2368 Bidirectional 100w Fast Charging Module - Ok for discharge only? - Page 1
Forum section: electronics / beginners

author: MathCa
author_rank: Contributor
timestamp: March 10, 2023, 05:59:48 pm
content: Hello,I ordered this fast charging module, but I can't use it to charge my battery pack because its maximum is 25Ah and mine is 32Ah. Or maybe I could but the charging current would just be lower?It's ok for me if I only use it for discharge, I already have a better charger. But do I need to add a diode or anything else to make sure it would never try to send current? It would be connected to a boost converter to receive more than 20v from the ~16v of the batteries to allow the 100W discharge.Thanks!" alt="" class="bbc_img" />

author: thm_w
author_rank: Super Contributor
timestamp: March 10, 2023, 10:42:20 pm
content: Aliexpress listings:https://www.aliexpress.us/item/1005003967532523.htmlhttps://www.aliexpress.com/i/1005003908841242.htmlDatasheet:https://file.yzimgs.com/398592/202213-225835877.pdfQuoteI'm not entirely sure what setting the FCAP value does here, it may be for battery charge state monitoring to give you an accurate LED display?But its not setting charge current as that is set by RISET:QuoteI would just set it to 25Ah, charge your pack, and do a capacity test and see what you get.Just make sure to use a BMS or protected cells, as recommended in the listing above.

author: MathCa
author_rank: Contributor
timestamp: March 10, 2023, 11:22:44 pm
content: Thanks! I translated the pdf with Google, it will be easier for me

author: MathCa
author_rank: Contributor
timestamp: March 11, 2023, 08:15:49 pm
content: I received it 15 minutes ago, and it works if I plug it directly into a power supplyonlyif I connect my phone first, connect the power supply, disconnect and reconnect the phone!I tried with my soldering iron, and nothing happened before "starting" it with my phone. I guess it needed to receive some power first (my phone can charge another device) to start.I guess it "thinks" the batteries are charged, the 4 lights turn on automatically once it's running.On the other hand, it charges my phone less quickly (~15W at 9v) than another module (30W) which was much cheaper! I thought this model supported more protocols than the other smaller ones, but no 🤷‍♂️ I have a S22 Ultra so with the right charger and cable I could get up to 45W.Both modules got almost 55W with my soldering iron at 20v.Sodo not buythis 100W if you don't want to also use it as a charger for your batteries!!The smallest, working normallyThe 100W
iPad charge rate vs battery life - Page 1
Forum section: electronics / beginners

author: Circlotron
author_rank: Super Contributor
timestamp: August 11, 2016, 12:45:39 am
content: It's not renewable energy but is is definitely a battery topic. I have an iPad charger with 2.4 amps output and an iPhone charger that has 1 amp output. If I am not concerned about the charging time would there be any benefit of using the smaller charger on the tablet seeing it would be gentler on the batteries?

author: bitslice
author_rank: Frequent Contributor
timestamp: August 11, 2016, 12:37:18 pm
content: Nope, it'll just charge slower.Batteries have a finite cycle limit anyway, only over heating or over discharge is likely to affect it.By the time the battery dies on an iPad you may want a faster version anyway, I'm still getting a whole day out of my original iPad 1 and I'm hoping the freaking thing dies soon so I can justify a newer one.

author: IanB
author_rank: Super Contributor
timestamp: August 11, 2016, 01:35:09 pm
content: My iPad takes over 3 hours to charge even with the standard large charger, which is within the normal range for a lithium ion battery. If the battery does not get warm during charging (mine doesn't), then I don't think there is anything to be concerned about.
Ipad electric shock - Page 1
Forum section: electronics / beginners

author: darthtony
author_rank: Contributor
timestamp: October 07, 2014, 08:01:52 pm
content: In my ipad 4 gen, if you touch the metal frame in a certain way, it gives a slight electrical shock(like an annoying tingle) only when it is charging(original charger). I have seen similar behaviour in some other consumer equipment like laptops etc. Why is something like this happening? I read somewhere that it is due to the fact that the metal parts arent grounded, but still why isnt it happening when it is not charging? Can someone explain this to me a little better?

author: Sebastian
author_rank: Regular Contributor
timestamp: October 07, 2014, 08:21:58 pm
content: I don't know for sure, but it is probably a small current passing through some insulation and/or the EMI capacitor of the charger.

author: Zepnat
author_rank: Regular Contributor
timestamp: October 07, 2014, 08:34:24 pm
content: I've experience this many times and can usually light one of those neon testers by touching some metal parts, but as I understand it it's perfectly safe although very annoying, there's a small chance you could drop something due to the unexpected shock.It's due to the charger being double insulated with no ground wire, and the tiniest bit of electricity being capacitively coupled (safe) from the mains side of the charger.

author: SoundTech-LG
author_rank: Frequent Contributor
timestamp: October 08, 2014, 07:43:07 pm
content: capacitively coupled (safe)unless the cap fails...

author: DanielS
author_rank: Frequent Contributor
timestamp: October 08, 2014, 08:03:10 pm
content: Quote from: darthtony on October 07, 2014, 08:01:52 pmWhen plugged into the charger, there is likely some leakage current coming in from the mains and since the adapter is only a two-pin thing, there is nowhere to reference the ground to so you end up with a floating voltage.You will often have a 1Meg or 10Meg resistor from output ground to mains neutra" to discharge static but if your AC plug is reversed, it will be connected to live instead, same if there is a Y-cap between output ground and mains neutral.If you get shocks from a laptop which has a three pin power plug, then you have a grounding issue.Your building wiring or outlets may have live and neutral swapped.

author: Rufus
author_rank: Super Contributor
timestamp: October 08, 2014, 08:29:20 pm
content: We recently had a thread about thishttps://www.eevblog.com/forum/beginners/ac-electrical-leakage-from-surface-pro-3!/15/

author: mikerj
author_rank: Super Contributor
timestamp: October 08, 2014, 08:37:34 pm
content: All Apple products with exposed metal cases suffer from this, e.g. early iPhone and iPods.
iPad Pro Display as External Monitor - Page 1
Forum section: electronics / beginners

author: Pereira98
author_rank: Newbie
timestamp: February 19, 2022, 10:21:32 pm
content: Hi, I own an iPad Pro model A1674 unfortunately with a broken motherboard from what I've been told. I was wondering if I could use the display as an external monitor for my Raspberry Pi. I've been searching for schematics with no luck. I read somewere that Apple uses eDisplayPort with these displays, but I don't know the pinout of their display connector.Help would be much appreciated
IPC-7351 component rotation confusion - Page 1
Forum section: electronics / beginners

author: frank26080115
author_rank: Regular Contributor
timestamp: April 01, 2013, 04:50:07 am
content: I need to generate a table of component placements so an assembly company can assembly my boards.The problem is knowing what exactly is "zero degrees" for each component. I found some documents and webpages (mainly this page and there's a link to another PDF on the bottom of that page)http://blogs.mentor.com/tom-hausherr/blog/tag/ipc-standards/Now here's the confusion, I take out a piece of cut tape with diodes, holding it with cathode on the left and anode on the right (as dictated by IPC-7351 document), the tape will have holes on the left side. I take out another piece of cut tape with some SOT-23-5 chips, hold it so that the side with 2 pins is on the right (as dictated by IPC-7351 document again), the tape will have holes on the right side.What the hell? Why is it different?The real problem is I don't know how to orient a lot of custom components in my CAD library, and I am trying to depend on the tape to tell me what the zero-degree orientation should be. If there is a discrepency between a diode and SOT-23-X, then I don't know which convention to follow.

author: free_electron
author_rank: Super Contributor
timestamp: April 01, 2013, 04:53:45 am
content: this is irellevant. don;t worry about it.the assembly people will verify the rotational offset.

author: frank26080115
author_rank: Regular Contributor
timestamp: April 01, 2013, 05:07:33 am
content: Quote from: free_electron on April 01, 2013, 04:53:45 amI don't know... They seem pretty busy, most responses were canned or even automated, and they've already missed some details during quotation.Should I take a survey of my own inventory and see which convention is followed the most, and then follow that, and then give the assembler a note saying so? This sounds like a good thing to do regardless, makes both of our lives a bit easier, in a way.

author: free_electron
author_rank: Super Contributor
timestamp: April 01, 2013, 05:12:05 am
content: again , it doesn't matter.they pre-run polarized parts and verify the correct orientation for 2 pin polarized parts.for multipin parts sot23 etc it don't matter as the machines camera will detect it. they have pattern recognition. during teach-in the machine detets it and correct automatically.i had an old Zevatech z750 that already could do that fully automatic and this was a 20 year old machine.

author: frank26080115
author_rank: Regular Contributor
timestamp: April 01, 2013, 05:20:06 am
content: Quote from: free_electron on April 01, 2013, 05:12:05 amAh, cameras, that's smartThis company does sound like they have some high speed high tech stuff... I hope you are right.Thanks
Iphone 5S schematic - Page 1
Forum section: electronics / beginners

author: Jane
author_rank: Frequent Contributor
timestamp: September 03, 2016, 08:17:35 am
content: I downloaded Iphone 5S schematic. I would like to learn how to read those schematic but do not understand what those small numbers( I put them into a red rectangle) mean.Can anyone please let explain what those numbers ( marked in red rectangle) mean?Thank you

author: tautech
author_rank: Super Contributor
timestamp: September 03, 2016, 08:22:56 am
content: Bus or Net #'s ?Are they duplicated elsewhere in the schematic?

author: Rerouter
author_rank: Super Contributor
timestamp: September 03, 2016, 08:28:20 am
content: If i recall, they are the page numbers those nets also connect at.

author: Jane
author_rank: Frequent Contributor
timestamp: September 03, 2016, 11:53:06 am
content: I also thought it was a page number but , when checking, it did not make sense.The complete schematic is athttps://www.ulozto.net/!QajKT3HZu/iphone-5s-820-3292-a-zip#_ga=1.1862388.498748459.1472901950Any idea what the numbers mean?Thank you

author: amyk
author_rank: Super Contributor
timestamp: September 04, 2016, 12:50:32 am
content: Definitely page numbers. If the schematic has been edited by someone else, they might not match up exactly but you should look for "sheet # x of y" or similar in the corner to find the corresponding page. You'll see these a lot if you look at laptop schematics too.
Iphone testing? - Page 1
Forum section: electronics / beginners

author: THATguy
author_rank: Regular Contributor
timestamp: February 19, 2017, 10:12:07 am
content: I want to test the internal components of an iphone (specifically 5s, maybe 6). However I believe there is a grounding feature between the screen & case (or main chassis screws) which prevent power on, not to mention 5s home button ribbon cable.Perhaps there is a specific forum somewhere for iphone technicians and if someone can provide links that would be amazing.I've seen the tear down sites and they are great for some basic component info, and entry/parts replacement.

author: LA7SJA
author_rank: Regular Contributor
timestamp: February 19, 2017, 05:10:24 pm
content: I would start watching this channel.https://www.youtube.com/channel/UCPjp41qeXe1o_lp1US9TpWA/videosJohan-Fredrik

author: retiredcaps
author_rank: Super Contributor
timestamp: February 19, 2017, 08:04:09 pm
content: Louis also has some info and a pay (I think $29/month) forum for answers.https://www.youtube.com/user/rossmanngroup/videos
IPOD HIFI dock/speaker constant buzz. where to find schematic? - Page 1
Forum section: electronics / beginners

author: N4v4jo
author_rank: Newbie
timestamp: February 29, 2024, 02:20:08 pm
content: Hi allI have an old IPOD HIFI dock-speaker. When I connect an Ipod in the dock or any audio signal in the AUX port I get a constant buzz. I'm trying to repair but I need the schematic. I have been searching for a couple of weeks already but I haven't found anything. Does anybody know where I could find it?.Thank you in advance.

author: Jwillis
author_rank: Super Contributor
timestamp: February 29, 2024, 11:21:16 pm
content: Schematics for an Apple product? Good luck with that.Ask Louis Rossmann about getting anything from Apple for repairs.With that being said I would check any coupling and decoupling caps. Specifically electrolytic capacitors concerning the power supply if the buzzing sound is at 120Hz. Check the dock connector for broken or deformed contacts.