hybridfree/eevblog-posts huggingface dataset:
How to diagnose always active button on a remote control - Page 1
Forum section: electronics / beginners

author: Saco
author_rank: Contributor
timestamp: November 17, 2018, 04:03:12 pm
content: Hello,I have a typical rubber-dome TV remote where I'm facing the opposite of the "normal" problem. Instead of a button not working, I have a button that is always active.Even after removing the rubber-dome panel and having only the PCB exposed, the button is still always active (I can see that, because when I put the batteries on, the TV LED keeps blinking. Only stops when I remove the battery).I tried cleaning it several times with Isopropyl Alcohol and contact cleaner to no avail.How should I go about fixing this? I am on a complete loss as I don't see anything that captures my attention.I have attached a picture of the PCB and a close up of the circuitry area in case it's relevant.

author: cvanc
author_rank: Frequent Contributor
timestamp: November 17, 2018, 06:20:16 pm
content: Can you re-post your photos with a circle around the button location that gives trouble?Also, here's a handy tip for troubleshooting IR remotes: Most cell phone cameras can see "just enough" IR to see the pulsations of the IR LED at the top of the remote. This is a Very Useful Thing some daysGood luck with your repair.

author: Twoflower
author_rank: Frequent Contributor
timestamp: November 17, 2018, 06:44:37 pm
content: Careful about the cell-phone cameras. That worked in the past. But newer ones might have a very well working IR cut-off filter. I fried one IR diode trying to get it working. My iFruit 4s main cam didn't see anything but the 'selfie' cam showed the IR-LED working. But as the secondary cams get better with later generations they might fail to see IR as well.One way would be first to try a working IR remote to test if the cam can see it or not.If you have a RasPi (or similar) you might get a universal IR receiver (e.g. TSOP31238) and get lirc up and running. Lirc might be able to tell the command that's transmitted.

author: wraper
author_rank: Unknown
timestamp: November 17, 2018, 07:02:43 pm
content: QuoteBut have you cleaned IC? I see something that looks like dirt on corrosion on it's terminals.

author: Saco
author_rank: Contributor
timestamp: November 17, 2018, 08:09:15 pm
content: Quote from: cvanc on November 17, 2018, 06:20:16 pmI can’t tell for sure what is the problematic button as all I know is I see the TV LED blinking. I assume it is the power button (top right corner) as the screen does not power on but I don’t know.

author: Saco
author_rank: Contributor
timestamp: November 17, 2018, 08:25:27 pm
content: Quote from: wraper on November 17, 2018, 07:02:43 pmI was tunnel visioned on the button contacts themselves so I had not invested too much on the IC. It is indeed corroded because of a leaking battery in the past. Now I gave it a vigorous scrub with a toothbrush and so far so good.Thank you for pointing it out!
how to disable loop and enable loop autrosafe control panel  - Page 1
Forum section: electronics / beginners

author: nyame
author_rank: Regular Contributor
timestamp: January 09, 2023, 01:45:42 pm
content: Hello everyonePlease i wish to learn on how to how to disable loop and enable loop autrosafe control panel, please any body that has experience working with this control panel should help me with the steps to disable loop and enable loop on the control panel, i have tried checking on Facebook but did not see any English regarding the control panel.Thanks
[SOLVED] How to disassemble Mueller banana plugs? - Page 1
Forum section: electronics / beginners

author: bluebird
author_rank: Contributor
timestamp: July 29, 2018, 01:20:25 am
content: UPDATE:Solution listed below. Method is also recommended by the manufacturer. Note: the plug is actually 1-piece NOT 2-piece. The inside part is hinged with a plastic tab (it's pretty tough but be careful not to break it). Apply rotational force when the inside part comes out.Quote from: tooki on July 29, 2018, 07:18:38 pmHi all,I recently bought a few pairs of Mueller banana plugs from Mouser belowhttps://muellerelectric.com/index.php/product/bu-16-0I was hoping they would come disassembled like the one in this video () but it turns out they came assembled like the ones in the product image. I tried to use a slotted screwdriver and compress the tabs one side at a time but they wouldn't budgeIf I work them harder I think either the plugs would break or I might end up stabbing myself with the screwdriver insteadAny idea what I should do and if there are any special pliers specifically designed to disassemble plugs like these? I'm planning to call the manufacturer on Monday but would like to see if anyone has a better idea here first.Many thanks!

author: tooki
author_rank: Super Contributor
timestamp: July 29, 2018, 07:18:38 pm
content: The Stäubli ones I use are similar. You have to go in from the end with a really thin screwdriver and pry it open, I'm afraid. (Like, lift the body over the tab.)
How to distinguish cell/wifi/bt/gps/nfc antennas with only eyes and multimeter? - Page 1
Forum section: electronics / beginners

author: 5au12
author_rank: Contributor
timestamp: October 01, 2025, 02:27:57 pm
content: Many phones/tablets or other devices don't have a reliable source of schematics, is it possible to tell each antenna's purpose myself?

author: ftg
author_rank: Frequent Contributor
timestamp: October 01, 2025, 02:50:21 pm
content: I think the only even semi-reliable way is with a VNA and a pile of adapters. Even then the antennas are meant to work with the device closed and in hand.THere is a chance that the NFC antenna will show a few ohms resistance instead of open or dead short, as it is likely a fairly large coil with some matching to resonate it on 13.56 MHz.But all other antennas can be either open or shorted to ground, depending on their construction.It does not help that all of them are multiband antennas.
How to do a cut in the middle of the polygon on Altium Designer 19?  - Page 1
Forum section: electronics / beginners

author: sidlauskas
author_rank: Contributor
timestamp: July 02, 2019, 08:45:20 am
content: Hi everyone,I'm wondering how to do a cut in the middle of the polygon using the Altium. It seems it has the tools just for making the cutouts and splitting the planes, but not making the cuttlines in the middle of the plane. Tried various methods to achieve this, but unsuccessfully. It would be great if someone could explain how this could be done. Thanks!

author: T3sl4co1l
author_rank: Super Contributor
timestamp: July 02, 2019, 08:02:13 pm
content: You mean to make not just a concave cut from an edge, but an actual disconnected hole within the polygon?Try a Polygon Cutout Region, or try pulling in the perimeter so it necks down then opens up to make the hole. The latter is not preferred because the minimum neck width trimming algorithm tends to clip corners even if they aren't acute corners, so the seam tends to have bites missing from it.Tim
How to do a group buy for 5 pick place machines, printers, and reflow ovens? - Page 1
Forum section: electronics / beginners

author: Merlysys
author_rank: Regular Contributor
timestamp: March 04, 2018, 08:10:33 pm
content: CHMT36: 2 heads + 29pcs feeders , Quantity: 1CHMT48VA: 2 heads + Vision + 29pcs feeders , Quantity: 2CHMT48VB: 2 heads + Vision + 58pcs feeders , Quantity: 2T961 ovens, Quantity: 3T962 or similar ovens, Quantity: 3Stencil Printer ( 3040 ) , Quantity: 1Stencil Printer ( 4432 ) , Quantity: 1I gathered together several local people wanting to buy these for their small production run.With prices of such machinery having come down I see many people looking into purchasing a unit so the actual quantities will likely be higher.We have a rough idea of the price we may get which is still a lot less than ordering online, especially as most of these sellers ship by AIR onlyNext step is to contact supplier in China, that is what I am not familiar with. I know about alibaba and aliexpress etc but looking at other methods to get the maximum discount.One route is to buy directly from the factory, another is to go via an agent. Agent doesn’t necessarily mean higher cost. I am also meeting a person who often goes to China to buy items in quantity (though not PCB related)Hoping to order by March 31st. Destination will be Toronto, CanadaWill be shipped by surface as AIR is very expensive for these bulky things. That is the reason I managed to get so many people. I am working on the legal issue so payment doesn’t go through me, thus making me not so responsible.

author: BrianHG
author_rank: Super Contributor
timestamp: March 04, 2018, 08:22:18 pm
content: Sorry for going all over your group buy.Good luck in finding a few more buyers.

author: FrankE
author_rank: Regular Contributor
timestamp: March 05, 2018, 06:23:31 am
content: I guess they're not in stock at Groupon.

author: Reckless
author_rank: Frequent Contributor
timestamp: March 12, 2018, 06:28:28 am
content: I will be interested in a T961 if its under $1000 USD. I am in chicago, not far from toronto.

author: michaels
author_rank: Newbie
timestamp: January 09, 2019, 03:35:48 pm
content: Hello Merlysys,Would you or other group buyers please share your experiences with theT961conveyor reflow oven? I'm thinking about buying one. And what was the price and supplier when you bought it in a group order?Thanks a lot for the advice.Cheers,Michael
How to do logic level compatibility for differential signals? - Page 1
Forum section: electronics / beginners

author: electrowhiz
author_rank: Contributor
timestamp: April 03, 2019, 12:08:06 pm
content: Hi All,When we do logic level compatibility or noise margin analysis for single ended signals we will check the below criteria:Voh > VihVol< VilHow we should do the logic level compatibility for differential signals?Thanks

author: Aggressive_Doughnut
author_rank: Contributor
timestamp: April 03, 2019, 04:23:57 pm
content: Most datasheets contain the information you are looking for:example. Generally, you are measuring the difference (V_ID which I always assumed means Input Difference Voltage) and determining if that difference surpasses a certain threshold.

author: tggzzz
author_rank: Super Contributor
timestamp: April 03, 2019, 04:49:26 pm
content: Common mode voltages should be compatible, i.e. mean output voltage within mean input voltage range specified by the reciever.Differential mode voltage should be compatible.If necessary, the max and min voltages should be compatible, but that is often implicit in the common and differential mode voltage specifications.

author: electrowhiz
author_rank: Contributor
timestamp: April 04, 2019, 01:26:47 pm
content: Thanks for the reply. I also have another doubt. What is the difference between AC logic level and DC logic level?

author: tggzzz
author_rank: Super Contributor
timestamp: April 04, 2019, 01:37:01 pm
content: Quote from: electrowhiz on April 04, 2019, 01:26:47 pmI don't recognise those terms. I could guess, but that would be a waste of everybodies time.
How To Do PCB Production Testing - Video - Page 1
Forum section: electronics / beginners

author: PCB1999
author_rank: Newbie
timestamp: July 21, 2016, 07:26:22 pm
content: Hi, I found it very clever to have the boards still in the array with power connected to each of them.I am not sure how to do that in Altium Designer 10. Is there an example of how this is done so I can try that in my next design?Thanks,Brian

author: ataradov
author_rank: Super Contributor
timestamp: July 21, 2016, 10:14:42 pm
content: I'm pretty sure Dave did a video on this, including Altium stuff. Now your search can be narrowed to EEVBlog channel aloneIt was for uCurrent, which further narrows the search.
Multichannel PAL/NTSC video stream into single USB to RaspPi - Page 1
Forum section: electronics / beginners

author: markj
author_rank: Newbie
timestamp: June 21, 2023, 09:01:28 pm
content: I've seen several similar items for the PC environment running proprietary SW.I'm wanting to capture multiple inputs from composite video cams and mux them into a single USB interfaced to a raspberry pi controller. I guess the architecture needs to include a analog multiplexer to start, maybe a video input/ capture controller?

author: Benta
author_rank: Super Contributor
timestamp: June 21, 2023, 09:45:29 pm
content: I only know of two products which will do this simply, and they're from the same supplier (I'm excluding pro equipment here, that's a different class/price/size).Terratec Grabster AV 400 and Grabster AV 450 (they're basically the same, except for the colour and accompanying software).Long obsolete, you'll find them nowhere except on eBay (or perhaps classifieds).Unique about them is, that they're 100% hardware devices with integrated MPEG-2 encoder.Input is CVBS or S-Video, PAL or NTSC, output is USB delivering an MPEG-2 stream directly to your VLC software (or whatever you're using).All other capture boxes I've seen are glorified A/D converters, where MPEG compression is done on the host PC (and all have proprietary/secret data formats).If you're quick, here are two:https://www.ebay.com/sch/i.html?_from=R40&_trksid=p2380057.m570.l1313&_nkw=terratec+grabster+av+400&_sacat=0Dunno if they'll ship to the US.You'll need an analog video multiplexer as front end, but that's pretty easy.

author: markj
author_rank: Newbie
timestamp: June 21, 2023, 11:16:52 pm
content: Thanks for your reply. So if I I need more control, and I was going to attempt this type of architecture myself, what are the correct functional blocks?Perhaps? composite video devices (cam) > analog video multiplexer (to combine multiple inputs into single stream) > codec chip (to digitize video stream) > video controller (to receive digital video stream to USB)?I did purchase one of these one eBay, which is along the lines of what I'm looking to do, except a) runs in windows environment and b) zero control.https://www.ebay.com/itm/252964079595?_trkparms=amclksrc%3DITM%26aid%3D111001%26algo%3DREC.SEED%26ao%3D1%26asc%3D20160811114145%26meid%3D030b4712657c457ba6441fdf1cd89530%26pid%3D100667%26rk%3D3%26rkt%3D3%26sd%3D284707371644%26itm%3D252964079595%26pmt%3D1%26noa%3D1%26pg%3D2351460%26brand%3DUnbranded&_trksid=p2351460.c100667.m2042

author: Benta
author_rank: Super Contributor
timestamp: June 22, 2023, 10:46:31 am
content: The problem with that one is, that it needs Windows software to work. So no R PI.Same is true for all other variants I've seen, though some support Mac as welll.The reason that I suggested the others are that they deliver a ready-made MPEG-2 stream that can be read by any type of computer.
How to do to have a signal of -30dbm    SOLVED - Page 1
Forum section: electronics / beginners

author: GGMM
author_rank: Frequent Contributor
timestamp: April 17, 2023, 02:29:23 pm
content: Hello,Beginner’s questionI need to test a spectrum analyzer I builtI must inject a -30dbm signal but never exceed 0dbm otherwise the input chip will burn.I have a FY6900 generator, I would like to start from a 1V (or other if it's need) signal, otherwise the one is in the noise if too low.My research gives me that a -30dbm signal corespond at a signal of 0.02vpp or 0.0070711 vrmssee here:https://coretechgroup.com/dbm-calculator/I only have a telonic 0-80db variable attenuator but 75 ohm.It can be used and what value to put to have about -30dbm?You tell me you plug in the generator on one side and watch the box with an oscilloscope before plugging in?In short, your best solutioncdt

author: GGMM
author_rank: Frequent Contributor
timestamp: April 17, 2023, 02:36:33 pm
content: the project is herehttp://www.carnut.info/tinySA/tinySA.htmlI drew inspiration from this site to build itit's a simpleSAcdt

author: coromonadalix
author_rank: Super Contributor
timestamp: April 17, 2023, 02:57:34 pm
content: for this case if you have friends or peoples who have professionals generators .... electronic shop ??

author: BillyO
author_rank: Super Contributor
timestamp: April 17, 2023, 03:07:22 pm
content: Speaking of sine waves...-30dBm is 7.07 mV into 50 ohms.If you cannot manage 7.07mV you could try 224mV through a 30dB attenuator into 50 ohms.Here's a good resource for such things:https://www.ahsystems.com/EMC-formulas-equations/dBm_Volts_Watts_Conversion.php

author: radiolistener
author_rank: Super Contributor
timestamp: April 17, 2023, 08:15:26 pm
content: -30 dBm = 0.02 VppBut note that FY6900 shows amplitude for unloaded output and has 50 Ω output.So, if you connect it to 50 Ω input device, you're needs to setup twice higher amplitude on FY6900, for -30 dBm you're needs to setup 0.02*2=0.04 Vpp. In such way you will get 0.02 Vpp on the output of FY6900 connected to your device input.But note this is right if your device input has 50 Ω impedance, for other impedance you're needs to recalculate amplitude.

author: radiolistener
author_rank: Super Contributor
timestamp: April 17, 2023, 08:18:16 pm
content: Quote from: BillyO on April 17, 2023, 03:07:22 pmnote that 7.07 mV is RMS voltage. But topic starter needs peak-to-peak voltage, because FY6900 doesn't support setup RMS voltage.In short:-30 dBm = 0.007071 Vrms = 0.01 Vpk = 0.02 VppSo, just setup 0.04 Vpp on FY6900 in order to get 0.02 Vpp on the loaded output and it will be -30 dBm.PS: and don't forgot to setup sine waveform.

author: GGMM
author_rank: Frequent Contributor
timestamp: April 18, 2023, 06:48:57 am
content: Thank's for your answer.I understood well how to do , you can lock my subjectthank youcdt
How to drive a weight scale? - Page 1
Forum section: electronics / beginners

author: facumedica
author_rank: Contributor
timestamp: May 01, 2014, 07:11:57 pm
content: Hey guys! I have a scale that I took from a scale that I took apartIt has 4 wires, which are 2 resistors. One of them is placed horizontal and the other is vertical. How do I drive it? In the original board there were some OpAmps and a microcontroller, not too much.Any information is welcome!Bye!

author: retrolefty
author_rank: Super Contributor
timestamp: May 01, 2014, 07:33:15 pm
content: Load cells are typically just a four wire resistive Wheatstone bridge. Two of the wires are to supply excitation voltage and the other two are the low level (millivolt output) measurement wires to be measured with a differintial input op-amp or possibly directly to a ADC that has programmable gain function.

author: facumedica
author_rank: Contributor
timestamp: May 01, 2014, 07:46:28 pm
content: Thanks for the info!
How to drive PN FET pair in high voltage H-bridge - Page 1
Forum section: electronics / beginners

author: IvanBayan
author_rank: Newbie
timestamp: September 06, 2018, 11:59:15 am
content: Hello.I trying to build H-bridge based on PN FET pair, I've found a lot of schemes for voltages below Vgs break voltage, but how to drive FETs if voltage above Vgs limit?I found scheme below:But don't undestand how it works, at the end right FET pair controlled by signal with 2*Vdd amplitude?Here is another solution which I found:If I undestand correctly, gate current will be limited by zener maximum current?Is there a well-known scheme for H-bridge which based on PN pair?Thank you.PSI know about solutions which based on N FETs and bootstrap capacitor, but them need PWM to keep upper N FET open.
How to elliminate low frequencies (RC Filters and co) - Page 1
Forum section: electronics / beginners

author: bitman
author_rank: Unknown
timestamp: December 13, 2018, 12:37:33 am
content: I'm "playing" with filters, practicing the formula and trying to apply them to practical use cases. One of the things I'm trying to do is to aplify the signal that the filter passes through, but I don't want anything on the lower frequences coming through. Since filters do not block lower/higher frequencies but just makes them smaller, is there any way to block unwanted frequences completely or how would you approach the issue of only letting frequencies higher than let's say 100Khz through to the circuit you want the frequency to control. In other words, frequencies lower than 100Khz would be considered noise.Is this "just" a game of averages where making the signal low enough that it has no real impact on the subsequent circuit?

author: rstofer
author_rank: Super Contributor
timestamp: December 13, 2018, 12:59:38 am
content: Filters can have very slow roll-off like a single pole RC filter at -20 dB per decade or something MUCH steeper like the Chebyshev Filter.https://blog.bliley.com/filter-typology-face-off-a-closer-look-at-the-top-4-filter-typesThere are also crystal filters which are very narrow in a pass band.In the end, the idea is to reduce the amplitude of the unwanted frequencies to the point where they don't unduly influence the output.And then there is the entire topic of Active Filters (op amps start to show up)https://en.wikipedia.org/wiki/Active_filter

author: mikerj
author_rank: Super Contributor
timestamp: December 13, 2018, 11:29:14 am
content: Quote from: bitman on December 13, 2018, 12:37:33 amEffectively yes, you choose your filter design so that out of band signals are attenuated sufficiently for your application. The perfect filter that you describe is commonly known as a "brick wall filter" and it's not implementable in practice. However multi-pole filters with sharp roll off and high stop band attenuation are realisable, though they often introduce their own problems. In the analog world component tolerances can have a significant impact the performance of multi-stage filters, introducing excessive ripple or peaking.
How to Enable Sleep mode - Page 1
Forum section: electronics / beginners

author: sambhu
author_rank: Newbie
timestamp: December 19, 2016, 12:45:13 pm
content: Hi ,I am trying to enable sleep mode for an avr-atemga256rfr2 mcu.The code is as followsCode:volatile int f_wdt=1;ISR(WDT_vect){if(f_wdt==0)f_wdt=1;}void enterSleep(void){set_sleep_mode(SLEEP_MODE_PWR_DOWN);sleep_enable();sleep_mode();sleep_disable();power_all_enable();}void setupWatchDogTimer(){MCUSR&=~(1<<WDRF);WDTCSR|=(1<<WDCE)|(1<<WDE);WDTCSR=(0<<WDP3)|(1<<WDP2)|(1<<WDP1)|(1<<WDP0);WDTCSR|=_BV(WDIE);}int main(){DDRD|=(1<<6);setupWatchDogTimer();while(1){if(f_wdt==1){PORTD^=(1<<6);f_wdt=0;enterSleep();}}}Here I just try to toggle an LED in an interval specified by watchdog timer.But with this code nothing could happen.Can anybody please help me to solve the problem
How to energize this relay - Page 1
Forum section: electronics / beginners

author: Cubbie
author_rank: Contributor
timestamp: December 29, 2024, 07:09:59 am
content: I want to use 2 of these Dowkey relays to switch a amp around a amateur radio transverter.Never used this kind before. Do I need some type of TTL control circuit after12 VDC is connected to white and black? Thanks......Jim

author: newbrain
author_rank: Super Contributor
timestamp: December 29, 2024, 08:23:15 am
content: Quote from: Cubbie on December 29, 2024, 07:09:59 amThe datasheet can be foundhere (Digikey).The description is very terse, but, yes, you need to provide both power, 12 V for your model at terminals + (1) and - (2), and two TTL control signals at the A (3) and B (4) inputs, according to the truth table below.No indication of the needed drive is given, but I would assume any reasonable 5 V logic family would able to drive it.The 12 V current consumption is about 220 mA.

author: CaptDon
author_rank: Super Contributor
timestamp: December 29, 2024, 05:11:47 pm
content: Interesting that they don't show the 0 0 state or 1 1 state! I would guess 1 1 is illegal and 0 0 is open?

author: floobydust
author_rank: Super Contributor
timestamp: December 29, 2024, 06:05:22 pm
content: It's a latching relay with mechanical linkage so the other states would not do anything exciting. Seems to have built in voltage reg and timer."switch" for pins 5,6,7 seem to be indicator (position) feedback.

author: Cubbie
author_rank: Contributor
timestamp: December 30, 2024, 03:08:19 am
content: Thanks for all the great info. Here is my plan to key the relays. I'm just showing one of relays.Maybe a little "Rube Goldberg" but, it should work to flip the states from 5 to 0.Sorry I can't seem to rotate the pic.
Enhance Piezo Transducer Waveform - Page 1
Forum section: electronics / beginners

author: quaternion00
author_rank: Contributor
timestamp: April 15, 2020, 01:46:27 am
content: Hi folks,I was driving a piezo transducer with 6V(peak-peak), 2 kHz using a function generator. I saw on the oscilloscope that the waveform didnot looked like a square wave. I know that a piezo transducer is like a capacitor. I thought that the distorted waveform wasdue to fast charging and discharging of the piezo transducer. So I tried to put a 1k resistor in parallel with the piezo and the waveform did not changed (still distorted). I tried decreasing and increasing the value of voltage and parallel resistor but the waveform did not changed .In my knowledge, the sound is louder when the piezo waveform is close to square wave. what are the ways to make the piezo waveform close to square wave so it will have louder sound? Attached is the piezo waveform I captured.Thanks

author: Vovk_Z
author_rank: Super Contributor
timestamp: April 16, 2020, 07:47:28 am
content: You can add some small resistance in series (instead of in parallel). It will lower the Q of oscillating (resonating) cirquit.Amplifiers usually don't like capacitance strait on their output so you have to separate it a little.

author: RoGeorge
author_rank: Super Contributor
timestamp: April 16, 2020, 07:59:08 am
content: Quote from: quaternion00 on April 15, 2020, 01:46:27 amWhere from did you got this info, or why do you think it should be like that?

author: pepelevamp
author_rank: Regular Contributor
timestamp: July 07, 2020, 12:33:37 pm
content: a square wave spends more of its time away from 0 volts than a sinewave does.if you crank up the gain on a sine wave to the point where its too loud for whatever ya playing it through it will clip or peak. this means the sine has gone so big its head and toes are cut off and you just get a square wave. music CDs that have been mastered by shit head audio mastering engineers are all cranked up so they are louder, but unfortunately it buggers the wave form and ya get crappy sound.

author: StillTrying
author_rank: Super Contributor
timestamp: July 07, 2020, 01:46:17 pm
content: "I was driving a piezo transducer with 6V(peak-peak), 2 kHz using a function generator."Are you sure it is a piezo, the waveform looks much closer to driving a 16 ohm speaker.
How to estimate dissipated heat - Page 1
Forum section: electronics / beginners

author: logancane
author_rank: Regular Contributor
timestamp: May 22, 2021, 01:08:34 am
content: Hi everyone,Is there a general method of estimating how much heat power an IC chip must dissipate for a given load? I don't want to use a temperature estimation because I know that the assumptions they make in the datasheets on convection flow and on ambient temperature are different to my situation.My first thought was to find an equivalent series resistance and use (I)^2*R to work it out, but there seems to be no reference to an IC ESR for most chips.If it helps, these are the chips in question, but really I'm looking for a method that I can use on most types of IC's (in the same way that you can bet most datasheets will have reference to thermal resistance).https://www.ti.com/lit/ds/symlink/lm5117.pdf?HQS=dis-dk-null-digikeymode-dsf-pf-null-wwe&ts=1621639942217&ref_url=https%253A%252F%252Fwww.digikey.co.nz%252Fhttps://www.ti.com/lit/ds/symlink/tps2663.pdf?HQS=dis-dk-null-digikeymode-dsf-pf-null-wwe&ts=1621639925302&ref_url=https%253A%252F%252Fwww.digikey.co.nz%252FAny help would be much appreciated!

author: amyk
author_rank: Super Contributor
timestamp: May 22, 2021, 02:10:12 am
content: P = IVEdit: nevermind, I see they are switching ICs. In which case the power dissipation will be proportional to the on resistance of the MOSFET.

author: cortex_m0
author_rank: Regular Contributor
timestamp: May 22, 2021, 02:47:00 am
content: The LM5117 is a controller, so there is no way to calculate power dissipation without completing the design. The gate drive will make a significant difference, which depends on the MOSFET you select. It is possible to calculate and sum the losses, and many simulation tools will allow you to do so as well. I think TINA-TI is among them, although I rarely use it.EDIT: Linear Technology App Note 140 goes into how to calculate this by hand for both linear regulators and SMPS.https://www.analog.com/media/en/technical-documentation/app-notes/an140.pdfThe TPS2663x does specify the Pass transistor resistance in several conditions on Page 8. The power dissipated in the chip, to a decent approximation is I**2 * Ron + VIN_SYS * IQ(on).
How to Extend/Expand Altium designer Schematic window - Page 1
Forum section: electronics / beginners

author: Simbarashe Bryne Chipembe
author_rank: Contributor
timestamp: February 06, 2017, 01:09:25 pm
content: Hi Guys,So I just started with Altium Designer moving from EAGLE, I would like know how if possible I can make my design space larger..(extend the borders). I have just placed one part and it almost takes up the whole window. I have many other parts to add to the design, please see the picture I attached below......Please assist, thanks in advance

author: electricar
author_rank: Regular Contributor
timestamp: February 06, 2017, 02:37:46 pm
content: Go to DXP - preferences - system - new document defaults - and change the schematic template to "A3.SchDot". After that add a new schematic to your project. It should be bigger now.If you cannot find the altium templates: they are stored in:C:\Users\Public\Documents\Altium\ADxx\Templates\

author: Bud
author_rank: Super Contributor
timestamp: February 06, 2017, 02:40:37 pm
content: I believe you can right-click on the schematic, go to "Document options" and change the document size there.

author: Simbarashe Bryne Chipembe
author_rank: Contributor
timestamp: February 06, 2017, 06:26:32 pm
content: Thank you very much lads! Works like a charm.
How to filter vibration noise from IMU data? - Page 1
Forum section: electronics / beginners

author: christheman200
author_rank: Newbie
timestamp: August 21, 2015, 06:03:50 pm
content: Hi all,This is going to be more software related than electronics, but I feel that some of you should know a thing or two about this. I'm using the Adafruit 10DOF IMU in an rc drone airplane, but realize it is extremely sensitive to vibrations induced by the motors. The results are similar to what is experienced here:https://www.youtube.com/watch?v=tNXcTY7Qecg.I've tried to isolate the sensor from the vibrations by placing it on a sponge, but this has little effect. So here's my question:What kind of software filter would do a good job to get rid of the effects of the vibration? Perhaps performing an FFT to find the most prominent frequencies and chopping them out, or simply running a moving average? I don't think a Kalman filter could work as I don't have a system model.Thanks for any help!Chris

author: unitedatoms
author_rank: Frequent Contributor
timestamp: August 21, 2015, 06:11:15 pm
content: The problem is more mechanical than DSP/Software problem. Mount the sensor in some thick foamy housing to get rid of vibrations. Signal wise, the foam is mathematically equivalentt to 3D low pass filter with lag proportional to mass of sensor subassembly. And wiring incoming into subassembly can be made spiraled/spring like to reflect vibrations back (lossless mechanical low pass equivalent). May be also replace wires with less rigid light weight wires.

author: christheman200
author_rank: Newbie
timestamp: August 22, 2015, 08:33:44 am
content: OK, after a bit more research I fed the gyro data into Matlab and ran a low pass filter on it. This worked well enough so I implemented it in live software. It seems to work well albeit the plane's response time is a bit slower. But only testing will see if my fixes work!
How to find a good PCB Manufacturer ? - Page 1
Forum section: electronics / beginners

author: jazzjessika
author_rank: Newbie
timestamp: March 04, 2014, 11:03:49 am
content: HiiiI want to know about pcb manufacturing process ?

author: zapta
author_rank: Super Contributor
timestamp: March 05, 2014, 11:30:11 pm
content: Hobbyist? Professional? What quantities? What country?For inexpensive prototypes ospark works great for me.

author: Falcon69
author_rank: Super Contributor
timestamp: March 05, 2014, 11:42:32 pm
content: I've been using Sitopway off eBay. I've been working with Kevin. While their boards aren't perfect, they are very good for the price. He ships it out fairly quick. Here in Washington, I get the boards 5-7 days after I order them.His prices aren't bad, and are more then fair. He sends extra too. my last order of 10 boards, which had 7 different designs on it and about 50 parts total, I got 2 extra boards (100 parts extra).His price is $40 for set-up fee for 10 boards, one design, and under 10cmx10cm (100cm2) $20 for shipping with DHL.If you want larger than 100cm2then it is $40 + 0.02per cm2. And if more then 1 design, add $10 per design.SO, if you want a board that is 106mm x 140mm and it has 4 designs, then price would calculate as...40+(10.6x14x.02)+40=$82.97add $20 for the shipping = 102.97 total for the 10 boards. But like I said, he usually sends extraAlso, He has stainless steel stencils for $20, or if you want them framed, they are $40. Not a bad price for a stainless stencil.He can do tabbed, v-scoring, and any cut out you have drawn at no extra charge, like alot of other companies do. He doesn't charge extra for quantities of holes. I think i had one board that measures just under 100cm2and it must have had 1500 holes in it (vias, mounting holes, through holes).If you don't want the boards with a tagged serial or inventory number on it like MANY companies do, simple just tell him, he doesn't put them on it.Jason

author: EEVPiobee
author_rank: Contributor
timestamp: March 05, 2014, 11:46:06 pm
content: Quote from: jazzjessika on March 04, 2014, 11:03:49 amI may suggest KAtronics on AliExpress... Great service, quick quote, Great great Production speed, under 2 weeks produced, shipped and flawless quality everytime...
How to find A1 pin SMD - Page 1
Forum section: electronics / beginners

author: Jane
author_rank: Frequent Contributor
timestamp: October 02, 2020, 08:44:50 pm
content: Is there any rule how to how to find the first pin on a very small SMD item? The SMD has 4 pins.There is only some text on it. Is the rule below a general rule for ALL SMD?if there is lettering on the chip then pin 1 will be at the lower left-hand corner of the chip when the lettering is upright and readable

author: ataradov
author_rank: Super Contributor
timestamp: October 02, 2020, 08:58:57 pm
content: There are no guaranteed rules. The only way is to follow the datasheet.Orientation of the text works most of the time, but not always.
How to find Capacitors by class (X1, Y2, etc)? - Page 1
Forum section: electronics / beginners

author: plus6dbE
author_rank: Contributor
timestamp: September 20, 2014, 05:07:55 am
content: What's the trick to searching for caps by class on DigiKey/Mouser/Newark/etc?I'm looking for some Y2 caps that are rated 470uF, 25V, and I can't find any mention of "class" on datasheets, etc.

author: Odysseus
author_rank: Regular Contributor
timestamp: September 20, 2014, 06:51:15 am
content: It's located in the "feature" parameter list, all the way at the right. And it looks like the highest you'll find is 45uF.

author: The Chump
author_rank: Contributor
timestamp: September 20, 2014, 09:43:26 am
content: You won't find any 470uF 25V capacitors rated Y2. That sounds like an electrolytic.All Y2 capacitors are rated for 250Vacor higher and are intended for safe connection across Live/Neutral to Earth.The datasheet will say Y2. If it doesn't mention it then it's not Y2.Surely, you aren't thinking of connecting a 470uF 25V anywhere near AC mains. (please, don't try!)AlexP.S. Where's the emoticon for setting your hair on fire?

author: plus6dbE
author_rank: Contributor
timestamp: September 20, 2014, 02:56:22 pm
content: bah! never mind - I was having a dyslexic moment there...thought I was looking at a Y2 cap, but no - it says "2Y" which I guess is something else.btw, what's the problem again with putting a 25v cap across the mains? (kidding, kidding)
How to find correct wires for analog intercom phone - Page 1
Forum section: electronics / beginners

author: symbianas
author_rank: Regular Contributor
timestamp: January 20, 2024, 02:53:06 pm
content: Hi, I have moved to flat which has intercom system "Miwi-Urmet 1131", but phone is missing, so I want to connect a new one, but need to know correct wiring.It seems to have 5 wires and be analog intercom system.Wires:White - maybe door lock or ground? when this wire is connected to green door lock makes some noise but does not unlock...Green - maybe ground?Red - maybe speaker but does not seem to work...Brown - seems to be microphone wire? when connected with green as ground other person hears me near the house entry. When white is connected as ground sound is bearable too but very distorted.Gray - Ringing wire? phone rings then this wire connected to RING and green or white is connected toWhen measuring with multi-miter white seems to be the ground 0V green 8V brown 14V. But microphone and ringing works then green is connected to the ground.The problem is that door lock and sound in flat is not hearable at all. So for some reason these functions do not work.Any ideas how to make this intercom phone working? Neighbors say that their phones do work, so intercom should be working...

author: SeanB
author_rank: Super Contributor
timestamp: January 20, 2024, 05:30:00 pm
content: Best bet is to look at the wiring for one of the neighbours, and connect yours as they are, as wire colour is not really set in the install manual. New unit will have the wires connected to the handset in the right order, so just install yours as they have. Just note that if there are jumper wires in the other phone, you need to install them as well.https://urmet.com.pl/INSTRUKCJE/1131_INSTRUKCJA.pdf
How to find mains push switch to use with a rod? - Page 1
Forum section: electronics / beginners

author: exe
author_rank: Unknown
timestamp: February 04, 2019, 07:46:26 pm
content: Hello again.TL;DR: I need a mains switch that would easy accept a push-rod button from front panel.A lot of professional equipment doesn't have a switch on the front panel, but rather have switch somewhere on the back that is activated by a push rod. Like here on the top (with a bit of green paint):https://xdevs.com/doc/Keithley/2400/photo/xDevs.com/_TIM5466.jpg.It's such a common thing, but I have troubles finding it. My main supplier (tme.eu) seems doesn't have anything remote that would be able to switch 250V, 120VA toroid transformer. I think I'm looking for something like this:https://www.ebay.com/itm/Fender-Push-button-switch-complete-kit-1-for-Elite-Bullet-Jeff-Beck-Strat-/263933639990, but speced for 250V.Do you guys have a suggestion what I could use? In the worst case the switch may not be rated for large current, I'll just use a relay.

author: Benta
author_rank: Super Contributor
timestamp: February 04, 2019, 07:58:25 pm
content: C&K:https://www.mouser.de/datasheet/2/60/ne18-1323323.pdf

author: exe
author_rank: Unknown
timestamp: February 04, 2019, 08:52:50 pm
content: That will do the job, thanks!
How to find out if PSU has current limitating circuit? - Page 1
Forum section: electronics / beginners

author: AndreyS
author_rank: Regular Contributor
timestamp: December 10, 2015, 07:16:11 pm
content: I have my very old ATX power supply unit AOpen FSP250-60ATV(Datasheet).I noticed 3 variable resistors on it. Two of them affect voltage outputs (12V, 5V, other I didnt checked). I want to use it to charge car battery (13.8V).It says 12V output can deliver 13A. Datasheet says over-load protection triggers on 24A.My question is does this PSU have current limiting circuits? Or the voltage just gonna drop when 13A exceeded?Or could anybody say how current limiting circuit looks like? Then I will find on my actual PSU (if this circuit is presented in PSU).PS: it has 3528 PWM IC.

author: Simon
author_rank: Unknown
timestamp: December 10, 2015, 07:18:20 pm
content: If you adjust the output it probably won't limit providing you don't exceed the current limit. But I would ensure you draw no more than the same watts and play it safe and draw a little less.

author: wraper
author_rank: Unknown
timestamp: December 10, 2015, 07:19:47 pm
content: There are no ATX PSUs with current limiting because it is completely useless and even dangerous for their native application. All of the more or less decent ones with protection present will just shut down if overloaded.

author: AndreyS
author_rank: Regular Contributor
timestamp: December 10, 2015, 08:00:20 pm
content: Quote from: Simon on December 10, 2015, 07:18:20 pmQuote from: wraper on December 10, 2015, 07:19:47 pmThank you guys for helping.Then if I exceed 13A, but not 24A the voltage would drop?PS: In the first post I typed only my guess, I'm not sure about voltage drop

author: made2hack
author_rank: Frequent Contributor
timestamp: December 10, 2015, 08:00:54 pm
content: They have current protection that are like "soft" fuses if you will.They very quickly shut down if you exceed the current. About a minute or so later, you will be able to turn them back on.

author: AndreyS
author_rank: Regular Contributor
timestamp: December 10, 2015, 08:17:59 pm
content: Quote from: trs80 on December 10, 2015, 08:00:54 pmThank you!
How to find out what voltage is needed for a circuit? - Page 1
Forum section: electronics / beginners

author: symbianas
author_rank: Regular Contributor
timestamp: February 03, 2021, 07:30:25 pm
content: Hi, I want to power BMW DSC sensor on my test bench, but don't know how much volts it requires.How could I find voltage value needed? Is it possible that it is powered by regular +12V? Or it should be less?Should I try to power it from low voltages and go up to see when its working?What power supply voltages are common for car sensors?

author: CaptDon
author_rank: Super Contributor
timestamp: February 03, 2021, 07:40:09 pm
content: Where is the rest of the diagram? It surely has more than two wires? Is it CANBUS powered?

author: symbianas
author_rank: Regular Contributor
timestamp: February 03, 2021, 08:27:08 pm
content: Quote from: CaptDon on February 03, 2021, 07:40:09 pmYes, its connected to F-CAN by 2 wires. In total DSC sensor has 4 wires: Ground, F-CAN+, F-CAN-, Supply. Supply wire is marked as 0.5mm2 thickness.Power supply of whole DSC unit:

author: symbianas
author_rank: Regular Contributor
timestamp: February 04, 2021, 03:08:03 pm
content: Should I try to power it from low voltages and go up to see when its working? Or is there any better way?Does the information that module is using CAN BUS suggests its power supply voltage?

author: CaptDon
author_rank: Super Contributor
timestamp: February 04, 2021, 03:19:41 pm
content: Our CANBUS sensors on GE/WABTEC locomotives are powered from +15vdc although they are simply automotive sensors which were used on cars at 12vdc. I think the BOSCH manufacturer spec says they will work accurately anywhere from 8vdc to 20vdc.

author: symbianas
author_rank: Regular Contributor
timestamp: February 05, 2021, 05:06:40 pm
content: I took apart the sensor, sadly it had tough plastic and I have damaged the board parts. But I am still interested to know what voltage it needs (If I will buy another sensor) so here its internals:GFE 5BA - diode ?TMS 980 - some kind of MCU by ATE5CT D47Y - some kind of chip ?A476C - capacitor 16VL4P 22 35V - capacitor551 U1D25LC040 - eepromCan this suggest the Voltage required?

author: mvs
author_rank: Frequent Contributor
timestamp: February 05, 2021, 05:45:08 pm
content: GFE with general semiconductor logo is SMCJ26A 26V TVS diode, so this DSC sensor is made for "12V" board supply.
How to find peak current of induction motor without datasheet - Page 1
Forum section: electronics / beginners

author: Dmeads
author_rank: Regular Contributor
timestamp: November 13, 2019, 12:53:53 am
content: Hello. I have a small induction motor, and I need to find the peak startup current but I dont have the datasheet for the motor.It is a mains voltage single phase motor with a total resistance of 151 ohms and 43mF of inductance measured.

author: Dmeads
author_rank: Regular Contributor
timestamp: November 13, 2019, 12:55:09 am
content: 43 mH sorry

author: langwadt
author_rank: Super Contributor
timestamp: November 13, 2019, 01:05:37 am
content: the 115 Ohm sets the max

author: floobydust
author_rank: Super Contributor
timestamp: November 13, 2019, 01:42:50 am
content: Like I said in your other post, lock the rotor and quickly measure it.https://www.eevblog.com/forum/projects/does-this-motor-have-a-datasheet/
How to find the correct replacement USB-C port - Page 1
Forum section: electronics / beginners

author: cb278
author_rank: Newbie
timestamp: May 20, 2025, 05:53:52 pm
content: Hi all,I've managed to disassemble an LG Xboom PN7 portable speaker in order to desolder the broken USB-C charging port.OK, so I managed to rip a few of the pads while desoldering the port, but I'm hoping they're either redundant or I'll be able to repair.My biggest issue however is, how on earth do I go about finding the correct replacement port?I've been looking through data sheets of USB-C ports on CPC and RS Components.e.g.https://uk.rs-online.com/web/c/connectors/usb-d-sub-computing-connectors/usb-connectors/?pn=4&selectedNavigation=attributes.USB_Type=Type%20CBut they all seem to have two rows of pins to be soldered whereas the original only has one row. Presumably because the original is for charging only whereas the ones I've found so far handle data too?I've attached a photo of the removed port along with dimensions of the port and the outer dimensions of the mounting pins and the same for the contacts.Any pointers will be much appreciated.

author: thm_w
author_rank: Super Contributor
timestamp: May 21, 2025, 12:23:50 am
content: Look on LCSC or Aliexpress instead to find an equivalent.What you have is a 12 pin model.https://lcsc.com/product-detail/USB-Connectors_Korean-Hroparts-Elec-TYPE-C-31-M-12_C165948.html?s_z=n_12%2520pin%2520usbc

author: cb278
author_rank: Newbie
timestamp: May 21, 2025, 11:15:52 am
content: Thank you. I looked at the data sheet for the one you linked but I'm getting confused. The diagram on the right shows 12 pins but the one on the left and associated pin-out shows 16 pins?It's a shame the filter controls don't have number of pins as a criteria.Are there any tricks when searching to help narrow down the field or is it just a case of painstakingly examining data sheet after data sheet til I find the right one?

author: DavidAlfa
author_rank: Super Contributor
timestamp: May 21, 2025, 02:40:23 pm
content: Quote from: cb278 on May 21, 2025, 11:15:52 amThe first two pins on each side are actually two joined together:A1/B12, A4/B9, B4/A9, B1/A12.It won't work with just replacing the connector...Both VBUS pads are knackered.

author: cb278
author_rank: Newbie
timestamp: May 21, 2025, 10:08:30 pm
content: Ah, that makes sense now. Thank you.I intend to take a closer look at the board now that I have a pinout to refer to to see if I can try replacing the ripped pads.