hybridfree/eevblog-posts huggingface dataset:
Energy Meter power consumption advice/help - Page 1
Forum section: electronics / beginners

author: andre123
author_rank: Newbie
timestamp: December 05, 2019, 09:52:01 am
content: I've been assigned to start working on a smart energy meter project, it's been like 10 years since i put any work in AC . I would be sincerely grateful for any constructive advice. Now the 3-phase meters i'm been assigned to work on are class 1 smart meters and apparently they need to comply with IEC62053-21 power consumption limits for voltage circuits which are as followsAlso the since the metrology part/ front end which consists of ,Current Measurement: Current transformer ( isolated from mains , no neutral reference need to be connected ).Voltage measurements ( need to be non-isolated and the neutral needs to be connected to the ground of the system ) ofcourse any modem or communication device is to isolated.The Main SOC (MCU+Metrology) is power hog and it apparently draws around 50 mA alone , the rest of the circuit probably another 20 mA maximum. I've been hinted to study the possibility of using dropper capacitor power supplies+ DC-DC regulators which have high input tolerance (60V) instead of transformer based AC-DC ones. I've been gathering all i can to fully understand the circuit to get 12VDC , seems i'm still going no where.For now my questions are the following,Which type of powersupply type (non-isolated) should i use while designing the power supply ( capacitor dropper,...etc) 10VA or 2W , based on my previous calculations 10VA @ 230V will give about 43 mA which is tiny ? I'm confused help ?How do i calculate the power efficiency of the dropper capacitor , i'm aware of the Pout/Pin but since this has capacitor the equation is not applicable ?All my findings and work are available here :https://www103.zippyshare.com/v/U7kgRZK8/file.html

author: Rerouter
author_rank: Super Contributor
timestamp: December 05, 2019, 10:01:44 am
content: I don't personally like capacitive droppers for long lifetime products.. but in this case because of the following switchmode your not limited to that 43mA, (also plan out your worse case, e.g. the biggest brownout the thing has to work through) e.g. lets say your device uses 50mA at 5V, well if you dropped your mains down to say 12V @ 43mA, then used a switcher to 5V, you end up with about 90mA,
Energy meter schematic query - Page 1
Forum section: electronics / beginners

author: Vindhyachal.takniki
author_rank: Frequent Contributor
timestamp: October 27, 2016, 02:05:44 am
content: I have made a schematic using ADE7753. Attached is the ckt.ADE7753 is powered from 5V & micocontroller is 3.3V one.1. In the ckt I found that neutral of system has to be shorted with microocntoller ground & ADE7753 ground. Is it ok? Is this how it is done?2. Is there any way I get to know that line & neutral are interchanged in the system. Because I have seen generally in house meters there is led indication showing if line is connected to neutral & neutral is connected to line.3. I have to connect it to 3.3V micocontroller. In datasheet of ADE7753 VIH is 2.4V or I think all ouput lines on SPI can be connected to MCU directly while for MISO I connected a 1K resistor in between. Is it ok?4. Max adc inputs for ADE7753 are 0.5V max. So calaculations for voltage are:R4: 1M (will connect two 500k in series)R5:1KAt 275Vacrms, 50Hz, Vp= 389VpSo voltage at input = (R5/(R4+R5) * Vp = 0.39So I think its ok5. Max cuurrent to be measured = 50AacrmsSo Ip= 70.71VWith CT of 1800:1; I = Ip/1800 = 0.039VWith burden resistor of 10ohm V = 0.392V6. Are above calaculations ok?7. Is ckt ok?8. Is there any example code. I found some of net:https://searchcode.com/codesearch/view/17414705/Will took reference from this code & see if it works.

author: LukeW
author_rank: Frequent Contributor
timestamp: October 28, 2016, 12:09:15 am
content: A few general things to consider:If you're not certain about what you're doing it may be safer to use a fully galvanically isolated system, using a current transformer and a potential transformer.That way it does not need to be referenced to the line or neutral at all, and you can connect your PC, microcontroller tools, scope etc to it while the system is online safely, without worrying about it.If you want a galvanically isolated voltage sensor, can you kill two birds with one stone and use the power supply transformer for an acceptable voltage waveform acquisition?If you're able to accept a system without galvanic islolation then the current transformer is a pointless waste of money - use a simple shunt resistor instead.

author: Vindhyachal.takniki
author_rank: Frequent Contributor
timestamp: November 06, 2016, 03:50:32 pm
content: 1. I need to do some processing & segment display to be added. That why MCU is interfaced.2. Data is displayed on LCD for outputting data.Link for my ckt query on AD devices forum:https://ez.analog.com/thread/88685Going to use last ckt I posted in it.
Energy meter tampered using a handheld EMP generator - Page 1
Forum section: electronics / beginners

author: kumar
author_rank: Contributor
timestamp: August 15, 2014, 05:31:34 am
content: An energy meter was tampered by someone using a handheld EMP generator. These generators are also known as slot machine jammer. Lot of them are sold through ebay.I tried to measure the signal using a spectrum analyzer and near field probe. But it jammed even the spectrum analyzer.Can any of you please tell me;1) What kind of signal they generate?2) Any counter measures for protecting the instrumentPlease advise.

author: amyk
author_rank: Super Contributor
timestamp: August 15, 2014, 06:55:01 am
content: It's likely similar to what an ESD gun would produce, so you can use ESD methods for shielding.

author: Legit-Design
author_rank: Frequent Contributor
timestamp: August 15, 2014, 10:57:03 am
content: Quote from: kumar on August 15, 2014, 05:31:34 amdid it break?Quote from: kumar on August 15, 2014, 05:31:34 amput it further away from the device, inverse square law.Quote from: kumar on August 15, 2014, 05:31:34 amthey are technically HERFQuoteOr some call them mini teslacoils, but usually they don't shoot any sparks. Make one too powerful and it can easily kill electronics. They induce a current in a trace or wire and if there is enough voltage it will either tell the microcontroller pin is high or even kill the micro. No need for contact like ESD needs.Dave actually did a teardown or money acceptor modules, you can see they use relays and mains voltages to tell the machine if a valid bill has passed so there is no change someone can come with their "EMP device" and have the machine add credit.Quote from: kumar on August 15, 2014, 05:31:34 amShielding, and not just esd shielding, if you really want to prepare for powerful "EMP guns" then you need EMP grade shielding, lots of metal surrounding everything. Also every pin needs to be able to withstand hundreds or thousands of volts and high energy since the emp gun and it's operator will continue to induce currents in there. Run every signal line inside well stitched ground planes, just like when trying to measure something that is susceptible to noise from environment. Or just surround the device with wires that will detect this kind of tampering. This tamper detection is tripped and device is useless or will show it has been tripped. I wouldn't be surprised if modern slot machines just sound the alarm when someone start firing their "emp guns" inside/outside them.

author: Psi
author_rank: Super Contributor
timestamp: August 15, 2014, 10:58:51 am
content: Quote from: kumar on August 15, 2014, 05:31:34 am
ENERGY SAVING LAMPS IN A DESK LAMP AND CMOS LOGIC - Page 1
Forum section: electronics / beginners

author: uknerd
author_rank: Contributor
timestamp: May 17, 2015, 12:00:47 am
content: Sorry if this a dumb questionbut has any one seen a flurescent energy lamp approx 30 cms above a pcb fry a componentiv had 3 4093's fry when left under a fluro lamp for about 10 mins (running)exact same psu and setup with the lamp off, works for an hour plus (tested to just an hour)thanksnerd
Energy/Power Meter Rated Current Spec - Page 1
Forum section: electronics / beginners

author: omega_
author_rank: Newbie
timestamp: August 31, 2015, 03:05:16 pm
content: Hi everyoneWas thinking of purchasing a power meter to sub-meter each room to track power consumption, and noticed something on the spec sheet i do not quite understand. There area options for say:1.5(6)A - max of 1300W2.5(10)A - max of 2200W5(20)A - max of 4000W10(40)A - max of 8000W15(60)A, max of 13000Wwhat does 10(40)A mean, does 10 refer to min current, while (40) refer to maximum current the meter is capable of handling?

author: mij59
author_rank: Frequent Contributor
timestamp: August 31, 2015, 03:30:37 pm
content: The nominal current rating of the kwh meter is 40A using a shunt resistor or current transformer, the nominal current of the internal kwh metering device is 10A.
Energy/safety mark identification  - Page 1
Forum section: electronics / beginners

author: jerrb
author_rank: Newbie
timestamp: July 03, 2023, 01:10:05 am
content: So, I'm restoring my laptop (I like shiny things) and that includes it's power supply and its label that's now scratched and ruined. So I'm redoing it. I've identified and reproduced all the certification marking, but I can't find anything about this one. Any idea?

author: ArdWar
author_rank: Frequent Contributor
timestamp: July 03, 2023, 01:43:29 am
content: Cambodian ISC mark

author: mengfei
author_rank: Regular Contributor
timestamp: July 03, 2023, 01:57:26 am
content: https://www.cerpass.com.tw/en-us/ima_cambodia_01

author: liaifat85
author_rank: Regular Contributor
timestamp: July 03, 2023, 07:30:56 am
content: You already got your answer. For more info you can see:https://commons.wikimedia.org/wiki/File:Cambodia_ISC_mark.jpghttps://www.iso.org/member/1901.html
Engineering mathematics book.....who was it by? - Page 1
Forum section: electronics / beginners

author: Faringdon
author_rank: Super Contributor
timestamp: September 17, 2021, 08:17:25 pm
content: Hi,Back in 1999-2002 I did a BEng electronics degree.Our course maths book was "engineering mathematics" by K.A.Stroud.However, i had a different book which was much clearer and better (IMHO) than Stroud's book.However, i cant remember the exact name of it or the author. Do you know these things?I think the book was called something like "engineering mathematics", but may have been "mathematics for electronics" or something.It may (or may not) have been by "Croft, Davison and Hargreaves"The thing i really remember about it, was that it had a picture on the front cover of the Dome in London. (Sydney opera house edited out)Do you know which book this was?

author: jpanhalt
author_rank: Super Contributor
timestamp: September 17, 2021, 08:22:59 pm
content: Have you looked under your bed?QuoteThat should be easy for YOU to figure out. Have you tried?

author: Benta
author_rank: Super Contributor
timestamp: September 17, 2021, 08:26:13 pm
content: Probably Erwin Kreyszig, "Advanced Engineering Mathematics". Not the opera house, but the SF Bay Bridge.

author: armandine2
author_rank: Frequent Contributor
timestamp: September 18, 2021, 10:07:12 am
content: [Ed. In the late 80s]Yes the Stroud books were the popular choice - there were other UK recommendations I remember, only one named Engineering MathematicsBalpai, Mustoe and Walkerand Mathematics for Scientists and Engineers by G Stephenson

author: voltsandjolts
author_rank: Unknown
timestamp: September 18, 2021, 01:04:19 pm
content: We have an intern here, was shocked to see Stroud book on their desk, still in the curriculum in 2021.It brought back bad memories of late night exam preps.
ENIGMA TOOL PROGRAMMER - Page 1
Forum section: electronics / beginners

author: Franco
author_rank: Newbie
timestamp: December 06, 2020, 02:40:08 pm
content: Hello everyone, I am looking for who can help me to build a Cable for ENIGMA programmer, I need the model "C4 cable", just to know the wiring diagram from DB-9 to DIP-8, then I can do it myself.If some else have this Enigma programmer and the "cable C4 or A4 adapter", could to the wiring diagram DB-9 to DIP-8 ??Thank you all.
Enocean ERP1 switch/ISO/IEC 14543-3-10 anyone? - Page 1
Forum section: electronics / beginners

author: i_like_sparks
author_rank: Contributor
timestamp: February 03, 2022, 11:55:52 pm
content: Hello,I am trying to decode ERP-1 (ultra-low power) packets sent by an Enocean energy harvesting (battery free) PTM module:https://www.enocean-alliance.org/wp-content/uploads/2020/07/PTM21x_User_Manual_May2020.pdfBut for the life of me I can't figure out the 4-bit (!) checksum.The general layout of a packet is here (page 22):https://fcc.report/FCC-ID/SZV-PTM215U/5115140.pdfIt appears that the body of a "telegram" consists of 6 bytes,<data> <address0><address1><address2><address3> <status|rc>There is some other encoding going on (8-of-12 plus inversion), which I'm pretty sure I have figured out (and passes all sanity checks). "status" is 4 bit and "rc" is a 4-bit checksum. From everything I can figure, the checksum should just be the sum of all 4-bit nibbles before. But on some messages, the switch appears to add 1 to the checksum. This is consistent, some switches do it on all messages, some switches only on some types (only press, or only release, etc.) Does anyone have an idea what might be going on or has some experience with that protocol?On a related note, does anyone have ISO/IEC 14543-3-10? The protocol seems to be built on it and I suppose the standard should be better documented, but it's quite expensive for a hobby project.
Enpaquetado of component Proteus 8.13 - Page 1
Forum section: electronics / beginners

author: Harol
author_rank: Newbie
timestamp: May 22, 2023, 03:57:42 pm
content: Hello ForoHow (skirting board) GRAPHIC 3x3 can package soket itself 1In an integrated GRAPHIC 4N28 2In such a way that you be left like the GRAPHIC 3, in Proteus 8,13Thanks Foro
Enterance exam question - Page 1
Forum section: electronics / beginners

author: eripaha
author_rank: Contributor
timestamp: May 18, 2016, 02:24:57 pm
content: I did a entrance exam that had following question. Calculate Vccwhen VL=6.5volts, R1 = 2k, R2 =4k, RL650, c1 = 3.2mF. Circuit has been powered up for a long time.they some how get over 20volts.... wtf is going on?What they got

author: Skimask
author_rank: Super Contributor
timestamp: May 18, 2016, 02:34:05 pm
content: And?

author: Ian.M
author_rank: Super Contributor
timestamp: May 18, 2016, 02:40:49 pm
content: Treating it as a potential divider gives a divider ratio of 0.65/(0.65+4/3) or 0.3277. Multiplying by the result above (before rounding) gives 6.5V. So yes, fractionally under 20V is the correct answer.

author: Jeroen3
author_rank: Super Contributor
timestamp: May 18, 2016, 02:52:00 pm
content: The decoy capacitor surely put people on the wrong track.
E/OT I/OT T-E/OT T-I/OT ET? - Page 1
Forum section: electronics / beginners

author: Mechatrommer
author_rank: Super Contributor
timestamp: July 04, 2010, 04:19:15 am
content: i got this from microchipDirect. i'm looking for SOT-23 packaging, so...what the heck the difference between E/OT I/OT T-E/OT T-I/OT?need help.

author: EEwannabe
author_rank: Contributor
timestamp: July 04, 2010, 04:35:55 am
content: Read the marking information at the back of the datasheet.Temperature range: E = Extended, I =IndustrialPackaging: P = PDIP, OT = SOT23 6-LD, MC = DFN 8-LDthe T at the end of PIC10F202(T) means tape and reelHope that helps.- Patrick

author: Mechatrommer
author_rank: Super Contributor
timestamp: July 04, 2010, 03:56:32 pm
content: thanx! seem the cheapest t-i/ot can do, for normal use right? ok thanx! problem solved!
Silicon Chip Mag (UK EPE) GPS-synced Frequency Reference - Page 1
Forum section: electronics / beginners

author: g0mgx
author_rank: Regular Contributor
timestamp: December 01, 2019, 09:50:51 am
content: Hi AllI have built myself the GPS synced frequency reference that was featured in Silicon Chip Magazine back in Oct 2018 and also more recently in Practical Electronics Oct 2019:http://www.siliconchip.com.au/Issue/2018/October/GPS-synched+Frequency+Reference+Pt.1?res=nonflashThere are some useful files here which I hope you will be able to access:https://drive.google.com/drive/folders/1ytFVLRi3dYImGWtByd7xdfiFW5mCnu4B?usp=sharingI **think** I have a problem with PSU filtering/decoupling (I've spent many a happy hour watching Daves videos on this subject) as the problem with the build is that the main oscillator looks very noisy and also the output signal has a lot of "interference" (dont know the correct technical term) in the signal.If you look at the video file at the link above, you will see that when the output is set to 10MHz there is a log of steady change in the signal, the "interference" coincides with the data burst from the GPS.There is also a video in the link above showing the "debug" point of the circuit - which is the clock output from the PLL and is a 40MHz signal - again this doesnt look very clean. I've tried (rather randomly) adding additional caps to the circuit - I've also done something the article suggests "the stability of the reference may be improved by reducing the impedence of ground tracks on the PCB" - smells rather fishy to mebut this is basically adding wire connections between a number of ground points. This mod improved the problem dramaticallty, but hasnt cured it.is anyone clever than I willing to take a look at the files in the link above and offer any suggestions (other than throw it in the bin) over what I might try to get this thing to function correctly.Thanks muchnessMark

author: g0mgx
author_rank: Regular Contributor
timestamp: December 02, 2019, 05:13:32 pm
content: In case the info isn't visible I've posted details here:https://g0mgx.blogspot.com/2019/12/practical-electronics-really.htmlGrateful for any help.Mark
EPE magazine - Page 1
Forum section: electronics / beginners

author: Davi
author_rank: Newbie
timestamp: February 14, 2016, 11:34:35 pm
content: I know this may not be the best place for this but I am a begginer.Has anyone purchased the EPE disk and been unable to actually open the files on it? I bought it a while ago and no matter what I do I cant open teh magazines.

author: Tandy
author_rank: Frequent Contributor
timestamp: February 14, 2016, 11:51:48 pm
content: They use some DRM extension that only works on the Adobe Acrobat Reader for Windows for their subscriptions, I'm not sure if they do the same for CDs.

author: Davi
author_rank: Newbie
timestamp: February 15, 2016, 06:34:27 pm
content: Sorry about the lack of details at the minute. I purchased the cd a little while ago but was busy at the time and totally forgot to post. I remembered the other night but I'm away from the cd at the moment. As soon as I get home I'll try it again and post a better description of the errors I'm having. Thanks for the help guys
Solved! - Page 1
Forum section: electronics / beginners

author: 001
author_rank: Super Contributor
timestamp: November 15, 2017, 06:57:08 pm
content: Photo 1 - two channels grounded but traces not parallel to grid (andnothorisontalanyway)Photo 2 - chanel 2 connected with 36" RG58directly(without any dividers) to build-in calibrator 2V 1kHz but fronts are uglyHow can I fix it?THANX! FIXED!

author: w2aew
author_rank: Super Contributor
timestamp: November 15, 2017, 07:18:56 pm
content: The tilt is often caused by an external magnetic field, sometimes even the earth's magnetic field. Most scopes include a "trace rotation" adjustment to correct for this. Usually, it's a screwdriver accessible trimmer accessible on the front panel. For some older scopes, there were wingnuts on the back of the scope that would allow you to physically rotate the CRT to correct for the tilt.The calibrator signal looks as expected. Remember, the sole purpose of the calibrator signal (which is more accurately called the "probe compensation signal") is to adjust the low-mid frequency compensation adjustment on 10x probes. It isn't really designed to drive coax directly.

author: 001
author_rank: Super Contributor
timestamp: November 15, 2017, 07:35:30 pm
content: Thanx a lot!I trim my scope now and what I see:photo 1 - calibrator and 1:10 probesphoto 2 - calibrator and 1:1 probesIs it fine?Signal front looks "reversed" isn`t it?

author: w2aew
author_rank: Super Contributor
timestamp: November 15, 2017, 08:04:02 pm
content: Quote from: 001 on November 15, 2017, 07:35:30 pmYour images look fine/normal. The calibrator is *only* intended to be used on 10x probes so that you can adjust their compensation adjustment. The rounded edges on the 1:1 probe (and your earlier direct coax image) is due to the higher capacitance that each of these connections have.

author: Gyro
author_rank: Super Contributor
timestamp: November 15, 2017, 08:18:17 pm
content: @001:https://www.eevblog.com/forum/repair/gw-instek-gos-653g-display-distortion/

author: james_s
author_rank: Super Contributor
timestamp: November 15, 2017, 08:25:14 pm
content: Epic? This looks like a very minor issue that is part simple adjustment and part user error.From the title I was expecting smoke damage and a crater in the PCB.
Epoxy filled thermal vias in D2PAK drain pad - Page 1
Forum section: electronics / beginners

author: ocset
author_rank: Super Contributor
timestamp: August 04, 2018, 11:04:43 am
content: We have a D2PAK FET thats dissipating 12W. It’s a linear regulator usage.The D2PAK rests on a 4 layer FR4 PCB which sits on thermal rubber pad which rests on an earthed heatsink.We need to have thermal vias under the D2PAK, actually in the drain pad… but we cannot have too many, due to the potential for solder wicking. Therefore, we wish to use epoxy filled thermal vias in the D2PAK drain pad…….to stop wicking..then we believe we will be able to have a good number of 0.4mm diameter thermal vias in the D2PAK drain pad….do you agree?

author: filssavi
author_rank: Frequent Contributor
timestamp: August 04, 2018, 11:42:03 am
content: There are specific processes and products that can be silk screened upon the pcb and after curing they can be put through the reflow process, they have also some thermal conductivity(still nothing compared to copper so the more VIAs the better) but 0.4 mm is too small, the producer of the paste I looked at (Peters) recommends 0.8mmThe best process though is still plugged vias
Eprom 27c256 D0-D7 data waveform - Page 1
Forum section: electronics / beginners

author: Daxxin
author_rank: Regular Contributor
timestamp: April 24, 2019, 08:14:42 am
content: looking with scope at the data D0-7 i get this shape ..thats a valid data , garbage , freerunning , Z-state ?

author: bson
author_rank: Unknown
timestamp: April 24, 2019, 08:15:40 pm
content: Check where you attached the probe's ground clip... this looks a lot like you don't have a good signal reference.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: April 24, 2019, 09:11:34 pm
content: Also, make sure probe is on 10x setting, and scope is >= 20MHz.Tim

author: Ian.M
author_rank: Super Contributor
timestamp: April 24, 2019, 10:30:47 pm
content: ... and that the x10 probe's compensation adjustment is set up correctly for the flattest possible tops/bottoms on the scope's test signal with no visible over/undershoot on the edges
EPROM adapter has mystery component on board? - Page 1
Forum section: electronics / beginners

author: Mp3
author_rank: Frequent Contributor
timestamp: January 05, 2019, 08:31:39 pm
content: Hello everyone.I've got a device which stores optional ROM based expansions on a custom PCB. I'm looking to make a batch of adapters to fit plain 27C010 onto a compatible adapter as these boards aren't really available anymore.It seems pretty straightforward as all but one leg seems to be connected in a very basic manner. However i'm confused by the small component at the top. I thought it was a tiny capacitor but it seems to be labeled "JP3" on the original boards. It doesn't look to be any kind of jumper though. Do you guys think it is a capacitor? On the other side of the board is nothing interesting, just the solder joints, but i wanted to include a photo of both sides.I've attached a photo of both sides of the board i am talking about. Thank you in advance for any assistance.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: January 05, 2019, 08:47:21 pm
content: It's a capacitor

author: Mp3
author_rank: Frequent Contributor
timestamp: January 05, 2019, 08:55:01 pm
content: Quote from: mikeselectricstuff on January 05, 2019, 08:47:21 pmThanks, what is its purpose in this circuit? I'm sure it is there for a reason but i am not too sure what it's needed for

author: JDubU
author_rank: Frequent Contributor
timestamp: January 05, 2019, 09:25:14 pm
content: Read this:https://en.wikipedia.org/wiki/Decoupling_capacitor
Eprom beginner programming help TL866 w/m27c322 etc. - Page 1
Forum section: electronics / beginners

author: Mikek400
author_rank: Regular Contributor
timestamp: April 26, 2016, 05:03:12 pm
content: I am a complete beginner with EPROMS.I bought the TL866 programmer so I could learn about Eproms and also have some fun putting custom games on game cartridges like the Sega Genesis / Mega Drive, NES, and SNES.I started with the Genesis / MD and managed to copy the exsisting chips in a game I have already. That worked no problem. The game had 2 8 bit chips in it which I duplicated using 2 m27c4001s.. The original proms were 256KB *kilobyte* proms programmed in an odd even arrangement. Anyhow, programming some games works but most don't and I'm not sure why. I think I am splitting the files up properly so, I am at a loss.So I decided to try to use a 32 bit 42pin eprom such as the m27c322 to eliminate the need for file splitting and possibly make this work.. I read that it was possible to program 42 pin chips in this post..https://www.eevblog.com/forum/blog/eevblog-411-minipro-tl866-universal-programmer-review/msg664955/#msg664955But I think I need a little more help.. I understand I need to take a breadboard and wire it up to match another chip, but what other chip should I select and how to split files to program properly... Back to splitting files... :-/Just looking for advice to get things off the ground.Thanks in advance.Mike
eprom id - Page 1
Forum section: electronics / beginners

author: jacobsladder1969
author_rank: Newbie
timestamp: November 28, 2015, 05:15:18 am
content: can someone id this chip?

author: SL4P
author_rank: Super Contributor
timestamp: November 28, 2015, 06:24:21 am
content: Merry Christmashttp://www.datasheetq.com/view.jsp?pn=93AA86C-I/OT&fac=Microchip&lang=en
Looking for an EPROM Programmer for M27C322 DIP42 - Page 1
Forum section: electronics / beginners

author: Mikek400
author_rank: Regular Contributor
timestamp: April 05, 2016, 10:12:49 am
content: Sorry for such a beginner question, I am just getting my first programmer.How difficult would it be to connect a M27C322 EPROM to a TL866 or an SP8-A programmer?If its not really possible, does anyone have a suggestion on an inexpensive eprom programmer which is capable of programming them?I'd prefer to get a USB programmer, but it seems that the only inexpensive solution is using a Willem parallel port EPROM programmer. Just seems like that device has many problems and can be quite a pain to get to work correctly.. I don't really miss the days of using the LPT port for anything other than printing.. Actually, now I think about it, it was a pain for that sometimes too. haha

author: danadak
author_rank: Super Contributor
timestamp: April 05, 2016, 10:14:58 am
content: What is the programmer, model, vendor....?Regards, Dana.

author: Mikek400
author_rank: Regular Contributor
timestamp: April 05, 2016, 10:21:41 am
content: Quote from: danadak on April 05, 2016, 10:14:58 amOops. Sorry, copy and pasting things I erased the model number.I was wondering how difficult it would be to get it to program on a TL866 or possibly a SP8-A.I don't have a programmer yet, but am trying to decide what to get. (I actually placed an order for a TL866 but canceled it once I realized I may not be able to do what I want with it)

author: krivx
author_rank: Frequent Contributor
timestamp: April 05, 2016, 10:36:11 am
content: The Tl866 only has 40 pins, so it can't directly program a 42 pin IC. You could build a one-off programmer for this part, or build an adapter to program in segments (i.e. 8Mbit at a time, re-routing address pins to the Tl866).

author: Mikek400
author_rank: Regular Contributor
timestamp: April 05, 2016, 11:13:39 am
content: Quote from: krivx on April 05, 2016, 10:36:11 amI will be completely honest here, I have never used a programmer before and I am really just getting started into learning about electronics.I'm pretty good at figuring out how things work though.. I can understand what you are saying about re routing the address pins and seems like it wouldn't be too difficult to get it working. Once I have the hardware in hand I guess I will look at pinouts and see what can do.On the other hand, I wouldn't even know where to start with building a one off programmer unfortunately.

author: danadak
author_rank: Super Contributor
timestamp: April 05, 2016, 11:23:48 am
content: This might be of use -http://www.racketboy.com/forum/viewtopic.php?t=25714Note that EEPROM programming is actually pretty simple, provide address, data, andpulse the HV line to the chip for a time period, then verify. You could do this in basic(if you do not know C) on a number of UPs.Regards, Dana.

author: madires
author_rank: Super Contributor
timestamp: April 05, 2016, 12:11:11 pm
content: If it's just a one-off for a few EPROMs, why not asking someone with a professional programmer (>40 pins)?
EPROM query - Page 1
Forum section: electronics / beginners

author: kelp
author_rank: Newbie
timestamp: February 28, 2018, 11:19:41 am
content: Hi,OK, this is a slightly odd query but I have some Intel 2716 (16Kbit) EPROM chips. I was wondering what is the main body of the chip made from, as in what material? Is it ceramic or something? For a project I'm doing I would like to paint / spray-paint the chip a certain colour, would this affect the chip working at all? Assume might create more heat in the chip if it's sealed with a layer of paint but I really want the chip to look good and I guess they don't heat too much (will be used in an old 8-bit computer).

author: Nusa
author_rank: Super Contributor
timestamp: February 28, 2018, 11:37:48 am
content: Ceramic.Electrically, you need to make sure the paint is non-conductive if it comes in contact with the pins.Thermally, unlikely to be a problem. It was common to put adhesive paper labels over these chips indicating how they were programmed. The labels sometimes had a secondary purpose of protecting the erase window from light, if exposed -- even room lights can erase chips if exposed long enough.I'd suggest that labels might be easier than painting, and will look more authentic.

author: kelp
author_rank: Newbie
timestamp: February 28, 2018, 11:44:53 am
content: Thanks very much for the quick reply. I've got some opaque labels which I'll also be sticking on top, sorry forgot to mention that. The reason for the paint was I wanted to make it look clean / new and ensure the paint gets to the sides of the chip itself as well as the top surface (I wasn't planning to paint the erase window but cover it during the painting so it wasn't a permanent thing). So I just want a good clean look to it. I think a label on its own, whilst looking fine from above won't look so good side-on. It's all just a cosmetic thing really to make the chip fit in with the rest of my project. (Also I was going to ensure no paint got onto the pins by, hopefully, covering them up somehow)

author: kelp
author_rank: Newbie
timestamp: February 28, 2018, 02:48:15 pm
content: Hah, sorry, I forgot that the pins of course come directly out of the side of the chip (brain not fully active today, apologies). I'll just find a way of covering them up so they don't get the paint on them.

author: helius
author_rank: Super Contributor
timestamp: February 28, 2018, 02:56:15 pm
content: perhaps use a liquid frisket on the pins before painting.

author: kelp
author_rank: Newbie
timestamp: February 28, 2018, 03:24:16 pm
content: Thanks. I've never heard of that and had to google it, looks good. So you put it on, it dries and then you peel it off?

author: kelp
author_rank: Newbie
timestamp: February 28, 2018, 05:10:17 pm
content: One final question : Any decent tips on buffing up the pins and making them shiny and new looking? (without ruining them obviously)
Eproms - Page 1
Forum section: electronics / beginners

author: lccjester
author_rank: Newbie
timestamp: March 30, 2023, 01:51:51 pm
content: hello and thanks for any help in advance. I need to covert a 6 chip set to a four chip set. I am working on an older CNC machine that had two boards with eproms on it and it was changed to an upgraded board that combined everything to one board. The problem is the new board was missing the four chip set that provided G-code. I have the six chips from the two board set up but only have room for four. I tried to to use Binwizard to combine the chips bin files but they won't read properly on the machine. I get a check sum error. When I tried different combinations the error would follow to which ever chip address that had the first bin files combined.

author: BillyO
author_rank: Super Contributor
timestamp: March 30, 2023, 02:17:02 pm
content: There is no guarantee that the new board addresses the memory the same as the old board. You will have to do some reverse engineering of the hardware before you can assemble the memory contents in an appropriate way.

author: CaptDon
author_rank: Super Contributor
timestamp: March 30, 2023, 03:12:30 pm
content: What is the part number of the old and proposed new chips? 2716? 2732? 27C64? A six to four swap doesn't exactly make sense. A six to three would make more sense since the chips usually doubled in size for each new product release. There is no guarantee that the new board even runs the same software or even uses the same processor as the old board.

author: lccjester
author_rank: Newbie
timestamp: March 30, 2023, 04:11:15 pm
content: the old boards were using a mix of 16megabytes and 32megabytes kind of randomly. The new board is similar in it has mixed chips as well. some of the chips on the new board were taken from the old boards when it was installed. Unfortunately I was not around when it was done a few years ago. I only have some old picture of the older boards. The machine laid dormant for years after the boards were switched but i have gotten it up and running it is just a pain to have to do all the part programing on the machine. I don't have any of the books that came with the machine so no wiring diagrams. I have seen on machining forums where guys have added the EIA function to machines that never had it but they had to get ahold of some used DNC boards that my machine still has and then add the chips. So I know if I could figure out the proper way to merge the bin files in the correct fashion it should work. If I burn the first four chips and put them in the sockets the machine doesn't alarm out but I don't have fully functioning EIA. IT will display some of the G code it just won't execute it.

author: CaptDon
author_rank: Super Contributor
timestamp: March 30, 2023, 04:47:30 pm
content: I'm curious, based on the proposed or assumed age of this machine do you mean 16kb and 32kb eproms and not megabit as stated. The 16kb and 32kb devices would be 24 pin. Anything else would be different. I haven't dealt with 32mb eproms. When we get into that many bits we are usually talking flash memory or possibly serial devices.
.EPS pcb layout from Eagle files? - Page 1
Forum section: electronics / beginners

author: Chris Wilson
author_rank: Super Contributor
timestamp: January 02, 2014, 11:46:22 am
content: I have two Eagle files and need an .EMS file from them. I do not have Eagle. I just want the file to print the transparency to etch a couple of boards. Can someone tell me if the files attached will convert to produce an .EMS file and what i need to do this please? Or if it's dead straightforward for an Eagle user, maybe they could convert to.EMS and post it up or mail it me....Thanks!

author: kc9qvl
author_rank: Regular Contributor
timestamp: January 02, 2014, 01:51:03 pm
content: If you are going to etch yourself. Just print the brd file as a mirrored black pdf.

author: Chris Wilson
author_rank: Super Contributor
timestamp: January 02, 2014, 01:56:28 pm
content: Thanks, I'll download it again, but if it had errors would the zip have even opened?

author: kc9qvl
author_rank: Regular Contributor
timestamp: January 02, 2014, 02:05:49 pm
content: Eagle is complaining about erc errors. not set junctions. Is this supposed to be a 2 sided board? ground plane on top?

author: Chris Wilson
author_rank: Super Contributor
timestamp: January 02, 2014, 02:23:05 pm
content: I thought it was a single sided board. Let me find the link....This was it:http://www.feedpopular.com/read/aHR0cDovL2NpcmN1aXRzZGl5LmNvbS9sbTMxNy1yZWd1bGF0b3ItYm9hcmQtcGNiLW1ha2luZy8=/TE0zMTcgcmVndWxhdG9yIGJvYXJkIFBDQiBtYWtpbmcgfCBDaWN1aXRzIERJWQ==Thanks.

author: kc9qvl
author_rank: Regular Contributor
timestamp: January 02, 2014, 02:33:51 pm
content: Ok for transparency method

author: Chris Wilson
author_rank: Super Contributor
timestamp: January 03, 2014, 10:58:10 am
content: Quote from: kc9qvl on January 02, 2014, 02:33:51 pmThat was really good of you, many thanks. If I print at 100% size straight from the .pdf file, should the image size be correct? Hole spacing for the header connectors and LM317 seem correct at 100%Thanks again!
Epsilon-Delta limit method - Page 1
Forum section: electronics / beginners

author: MathWizard
author_rank: Super Contributor
timestamp: January 19, 2023, 11:30:47 am
content: I'm reviewing some early calculus again, like limits, for doing more stuff with step and impulse functions. And I'm wondering if there's anything wrong with doing it this way, since I don't remember people doing it this way, and neither my calculus books or pdfs do it directly. And I lost my real analysis book years ago.So for finite limits anyways, since the definition uses the assumed limit L, and we know x-->c , so we know c.So I'm been just solving some directly plugging x=c+delta, into the |f(x)-L| < e, and it works so far.https://www.ocf.berkeley.edu/~yosenl/math/epsilon-delta.pdfSo in problem 4 on the bottom of page 3, you would get the polynomial | (delta)^2 +5delta | < eWhich solves for any chosen positive e, you'll get 1 good delta answer.And for positive delta and epsilon, the pdf works out the same thing basically, and says|x-2|=delta < (e/6) ==> 6delta < e (or equal)so with the substitution way , so long as delta is between [0,1], I have(delta)^2 +5delta < 6delta (or equal) and that's always true. And it worked for the negative delta aswell.And thats way shorter that counting/ordering number line wayFor something like 1/x, I'd say treat L as finite , L=1/delta and try induction type steps and say it goes to infinity. But I was only going to review improper integrals.

author: dmowziz
author_rank: Contributor
timestamp: January 21, 2023, 10:20:48 pm
content: Hi MathWizard,Firstly, I think maybe there is a mistake in the attached pdf...The 1st attached image (between page 3 and 4)...It says that |x + 3| < 6... If this is the case and epsilon (e) is positive then the last equation in my attached image is not correct.. Yeah?That is |x + 3| < 6 does not mean that (1/ |x+3|) < 1/6.... It is greater. Yes?Am I missing something?I most likely am

author: ledtester
author_rank: Super Contributor
timestamp: January 22, 2023, 01:45:18 am
content: Quote from: dmowziz on January 21, 2023, 10:20:48 pmThe solution just goofed writing out the inequality -- the \$\frac{\epsilon}{|x+3|}\$ and \$\frac{\epsilon}{6}\$ terms should be swapped. They just got done saying that if \$|x-2| < \frac{\epsilon}{6}\$ then \$|x-2| < \frac{\epsilon}{|x+3|}\$ because \$6 > |x+3|\$.
Epson projector HDMI ports both fried. Where can I begin checking/measuring? - Page 1
Forum section: electronics / beginners

author: peanutismint
author_rank: Newbie
timestamp: April 03, 2025, 11:21:47 pm
content: Photos of the board are linked here:https://imgur.com/gallery/epson-powerlite-home-cinema-8700-ub-hdmi-failure-j2GbTx6In the second/third pics you can see where the 2 x HDMI ports are connected to the board (the large white areas)Amateur electronics repair guy here.I have this Epson PowerLite Home Cinema 8700 UB projector (model H419A). It’s been working great for a couple of years, until a few months ago I was re-plugging the HDMI cable and there was a small spark as I plugged it in and now the HDMI input no longer works.I thought it was weird but didn’t have time to diagnose it so I’ve just been using the second HDMI port, until lo and behold this week I turned on the projector and now the second port is also seemingly fried. VGA port still works (but for how long?!)The signal path into the projector comes out of my Denon home theatre receiver, to an HDMI over ethernet transmitter, over cat 6 cable to the receiver (which is powered by PoE) and then into the projector via a very short HDMI patch cable.I confirmed that the projector (and everything else in this chain) still works by using an HDMI to VGA adapter cable, but I’d rather not keep just using the VGA port because the picture is not quite as clear as HDMI (and there’s a 1-second delay in the video when using this VGA port).I can’t see any obvious damage, like a blown component or any kind of burn marks on the circuit board (at least not on the top; I haven’t yet taken the board out and flipped it over…) But I’m wondering if anyone can suggest the best way to start troubleshooting This fault? Would the schematic be pretty easy to get ahold of, and if so would it be as simple as just starting to probe a few of the most common components and checking resistor/capacitance values to see if something blew, or even just checking for continuity to see if the signal path is still good?

author: wraper
author_rank: Unknown
timestamp: April 04, 2025, 12:59:11 am
content: Fried in what way? Is it detected by computer but shows no image or not detected at all?

author: fzabkar
author_rank: Super Contributor
timestamp: April 04, 2025, 04:32:51 am
content: You may have killed the ports due to a difference in earth potentials (is one device powered from a 2-pin mains plug?). Often (usually?) these ports will be protected by ESD diode arrays. Perhaps they are on the other side of the board. You could measure the resistance between ground and each pin in the connector. These diodes usually fail shorted.That said, if you damaged both ports after that single spark, then the common factor would be the IC.
Equation explanation - Page 1
Forum section: electronics / beginners

author: omglol
author_rank: Regular Contributor
timestamp: January 14, 2018, 10:46:51 pm
content: Hello!I am looking at diode rectifier circuit and the equations about overlap on this page:http://people.ucalgary.ca/~aknigh/vsd/ssim/vsi/co.htmlI do not understand certain step - at the point where it is written "Equating the two expressions above":Va(t) - Vb(t) = - Vll sin (omega t)Why is it MINUS (-) Vll? Isn't Va(t) - Vb(t) just phase-to-phase voltage, so +Vll?

author: Asuka
author_rank: Regular Contributor
timestamp: January 31, 2018, 12:20:54 am
content: Quote from: omglol on January 14, 2018, 10:46:51 pmThere are many other mathematical errors in the equations and spelling mistakes in that document, so perhaps the author made a mistake here too. Perhaps you could email him and ask about it, he may be glad that someone found a typo for him.

author: omglol
author_rank: Regular Contributor
timestamp: January 31, 2018, 10:29:44 pm
content: Quote from: Asuka on January 31, 2018, 12:20:54 amHi! Thank you for your reply. Could you point out the mistakes for me? I don't dare to correct something I do not understand fully.

author: Asuka
author_rank: Regular Contributor
timestamp: February 01, 2018, 02:19:46 am
content: Quote from: omglol on January 31, 2018, 10:29:44 pmFor example,Quoteshould be "find". If you don't dare to correct things though, a better approach might be to just ask a question to him.

author: omglol
author_rank: Regular Contributor
timestamp: February 01, 2018, 05:57:54 pm
content: I mean mathematical mistakes, not spelling ones ...

author: Asuka
author_rank: Regular Contributor
timestamp: February 01, 2018, 11:18:42 pm
content: Quote from: omglol on February 01, 2018, 05:57:54 pmFor example, in the first integral on that page, the limits of integration are from zero to gamma, but the integrand is dt. It should be d(omega t) or better d(theta) or something, since gamma is not a time but an angle. Then he has fudged the error in the next line with the result of the integral.A wise man once said: Where there are spelling errors, there are other errors.
Equation Writer For Crib Sheets - Page 1
Forum section: electronics / beginners

author: rstofer
author_rank: Super Contributor
timestamp: November 07, 2017, 06:16:16 pm
content: Suppose a STEM class allows the use of a 2 sided sheet of crib notes for exams. It would seem that a nice way to do this is with some kind of equation writer. Hand written in pencil is probably the worst solution.Any thoughts on which equation writer? The primary platform is Win 10 but Linux isn't out of the question if the features warrant the reboot.Yes, the class will be part of a EE curriculum.

author: KMoffett
author_rank: Regular Contributor
timestamp: November 07, 2017, 06:30:12 pm
content: WORD has an Equation editor. Tool bar> Insert> right end> pull-down Equation and Symbols.My guess that Paper and Pencil would take less time than the learning curve.Ken

author: T3sl4co1l
author_rank: Super Contributor
timestamp: November 07, 2017, 06:31:04 pm
content: Use LaTeX, or more accessible, MathJax? Very pretty results, only somewhat cryptic to write:\[ x = \frac{-b \pm \sqrt{b^2 - 4 a c} }{2a} \]Tim
Equipment for beginner  - Page 1
Forum section: electronics / beginners

author: isophia
author_rank: Newbie
timestamp: July 25, 2013, 11:20:06 am
content: Hi, I just took some training doing both JTAG and BGA Chip-off to extract data personal devices (cell phones, pda, voice recorders etc). I'd like to setup a little home lab to get more practice. Keeping in mind that this is out of my pocket and not for business purposes, I'd like to get mid to good quality devices not expensive commercial equipment. The gear we used in training was a bit blah. I know there are better options out there. Here's what I'm looking for and what I'm thinking of so far.Soldering Iron - Hakko 888DHot air blower -Preheating station - Aoyue 853A (or one of the variants ++ )DC Power supply (I will be powering cell phones, tablets etc, small electronics) -Heat gun (max 1000 deg F) - Wagner HT1000That's it for now. I may want to get a fancy microscope as well but I can live w/o that for now.One bonus thought, if any of the gear is dual voltage that be great. I'm in the US but may end up dragging all this gear to Australia. If not, then US compatible is fine.