hybridfree/eevblog-posts huggingface dataset:
signet oscilloscope stb3 demo board  - Page 1
Forum section: electronics / beginners

author: chom125
author_rank: Newbie
timestamp: September 25, 2023, 01:47:35 pm
content: Hello AllI just purchased the Signet stb3 demo oscilloscope training board. The reason I purchased it was to learn more about how to use the oscilloscope. Unfortunately, I need more hope than just a manual with pictures. I also looked on YouTube for training videos.I need step by step help or at least a better training manual that goes into more detail and pictures of set-ups. Can anyone help?

author: mwb1100
author_rank: Frequent Contributor
timestamp: September 26, 2023, 07:55:51 am
content: I don't know if this would be any help unless you still have the opportunity to return the STB-3.Batronix in Europe (they ship to USA) have recently come out with their own demo/training board for MSO's:-https://www.batronix.com/shop/demoboards/Batronix-MSO-Demo-Board.htmlThe manual is quite nice; you can download it fromhttps://www.batronix.com/files/Batronix/MSO-Demoboard/Batronix-MSO-demo-board-web-EN.pdfThere's a forum thread about the board that includes quite a few examples of people putting the board through its paces:-https://www.eevblog.com/forum/testgear/new-scope-demoboard-from-batronix/If you can't return the STB-3 but you want to try out the Batronix demo board, I have heard that you can eBay oscilloscope demo boards for near the retail price (of course, you take the eBay fee hit). I don't know how quickly they might sell though.

author: tautech
author_rank: Super Contributor
timestamp: September 26, 2023, 07:56:22 am
content: There's not really a hold your hand manual for these other than the online manual.https://siglentna.com/wp-content/uploads/dlm_uploads/2018/07/STB3_User-Manual_UM60109_E01B.pdfOver the years I have posted many screenshots of its features and a Search for STB-3 will find them.Many of its waveforms are tests of DSO competency where you needdrivethe DSO to get the correct result therefore Autoset just won't cut it for many of its waveforms.I can help as time allows. What DSO do you have to use it with ?
SIL vs SIP, SIL == SIP? - Page 1
Forum section: electronics / beginners

author: onesixright
author_rank: Frequent Contributor
timestamp: January 12, 2017, 10:02:25 am
content: I'm confused, are these the same? Or is there any difference?SIL =SingleInLine PackageSIP =SingleInLinePackageSo: SIL == SIP ?Can't find much on SILhttps://en.wikipedia.org/wiki/Dual_in-line_package#Single_in-line

author: Ian.M
author_rank: Super Contributor
timestamp: January 12, 2017, 10:10:22 am
content: SIL isn't restricted to IC package pinout, it applies to other components e.g SIL headers or resistor arrays. SIP implies an encapsulated IC-'style' package.

author: onesixright
author_rank: Frequent Contributor
timestamp: January 12, 2017, 11:18:51 am
content: Quote from: Ian.M on January 12, 2017, 10:10:22 amAh, thanks!The PIN spacing voor SIL-4 and SIP-4 is actually same?
Silhouette Cameo for less than 0.5mm pitch - Page 1
Forum section: electronics / beginners

author: electrotwelve
author_rank: Contributor
timestamp: November 23, 2015, 03:50:03 pm
content: I'm considering buying a Silhouette Cameo or making myself a laser cutter (following an instructable). Just wanted to know which would be a good idea. I'm told the Silhouette Cameo does a tidy job at 0.5mm pitch but can it go any lower? Would the laser be able to do this? Would it burn the material?
Silicon chip pcb ordered from China - Page 1
Forum section: electronics / beginners

author: lentildude
author_rank: Newbie
timestamp: January 02, 2013, 11:05:44 pm
content: Hi,I was wondering if anyone knows a contact in China for ordering Siliconchip pcb boards. ie where they already have the artwork and can quote board number. Or where can I dl pcb artwork to send to china to make?I want to buy about 10 pcb for code 10108121 Mains timer project.thanksld

author: mianchen
author_rank: Regular Contributor
timestamp: January 03, 2013, 12:06:16 am
content: Quote from: wilfred on January 02, 2013, 11:39:30 pmWho'd want to buy EPE's amateurish overpriced boards? No solder mask, no silkscreen, badly tinned, single size drilled holes (1.0mm for an M3 screw hole?)...Not sure about SC's boards in OZ, but I'd strongly recommend anyone not to buy any from EPE UK (Winborn publishing or something)...
Silicon Encapsulated Electronic Board - Page 1
Forum section: electronics / beginners

author: theblast
author_rank: Newbie
timestamp: June 21, 2022, 10:17:42 pm
content: I have a broken battery drill controller card.It is plastic that the board is in and then ecapsulated with silicon all around.I removed a lot of the silicon with a heat gun and something to scrape the silicon of.Not easy to take off and very easy to brake things.Is there anyone who have a more delicate way to remove the rest of the silicon?A way with less chance to destroy components in the process.Someone who know how these controller board works, who can give me some tips in the troubleshooting?The Battery drill died when i dropped it from short height, but it fallen from higher height before. It was a crack in the plastic of the encapsulment.Board is very protected, but i guess something can have happened on the board from the shock.

author: Benta
author_rank: Super Contributor
timestamp: June 21, 2022, 10:38:29 pm
content: I think you mean "silicone" (think Pamela Anderson).Heat is not the best idea.Mechanical removal with tweezers is better, assisted with a bit bit of acidic acid, eg, using a small brush. The parts will survive that, but rinse with demineralizrd/boiled water at the end.But it stinks.

author: Foxxz
author_rank: Regular Contributor
timestamp: June 22, 2022, 01:38:03 am
content: Soak it in silicone personal lubricant which will will soften it
Silicon "germanium" diode? - Page 1
Forum section: electronics / beginners

author: dusan
author_rank: Regular Contributor
timestamp: August 20, 2022, 09:36:04 am
content: Can somebody explain this double speak to me?Datasheet:https://www.nikom.biz/pdf/1N60_DEC.pdfDo they just call it "germanium diode" but it is shottky silicon diode?

author: Terry Bites
author_rank: Super Contributor
timestamp: August 20, 2022, 12:14:59 pm
content: Its a point contact diode.www.rfwireless-world.com/Terminology/Point-Contact-Diode-Vs-Hot-Carrier-Diode.htmlOld School but very handy in RF detectors. Theres a clue to its age in the part number.Note the very, very low junction capacitance and tiny Vf at low currents.Its the crystal in a crystal set.https://en.wikipedia.org/wiki/Crystal_radioAlso very popular in distortion pedals back in the day.

author: dusan
author_rank: Regular Contributor
timestamp: August 20, 2022, 12:34:44 pm
content: I don't think it's point contact, I don't see a wire thare. Point contact are usually in DO-7 package, this one is DO-35.Here on the left is DO-35 planar diode and on the right is DO-7 point contact diode:https://www.nasobchodik.sk/images_101197-2/1n34a-1n270-do-35-do-7-moc-germ%C3%A1nium-usmer%C5%88ova%C4%8D_thumbs.jpeg

author: Wallace Gasiewicz
author_rank: Super Contributor
timestamp: August 20, 2022, 01:03:30 pm
content: A 1N60 is a Germanium diode. It is used a a detector/RF rectifier in radios.Measure the voltage drop with a multimeter. A Germanium diode will have about a .3 V drop. Silicone have about .6 volt drop.Shottky diodes have less drop. .2 V or so.These are the point contact or hot carrier diodes.More modern replacements for Germanium diodes.

author: wraper
author_rank: Unknown
timestamp: August 20, 2022, 01:13:21 pm
content: Germanium part number reused for silicon Schottky diode.

author: bd139
author_rank: Super Contributor
timestamp: August 20, 2022, 02:41:35 pm
content: Correct it’s a silicon Schottky diode. They are actually slightly inferior to Ge diodes at very low forward bias.

author: Terry Bites
author_rank: Super Contributor
timestamp: August 20, 2022, 05:31:09 pm
content: I'm sure I have some fossil ones. Or do I .....

author: MikeK
author_rank: Super Contributor
timestamp: August 20, 2022, 05:38:22 pm
content: Beware, some "germanium" diodes are fake:https://youtu.be/Lyos1D7_2OI
Silicon wafer testing? - Page 1
Forum section: electronics / beginners

author: haxtormoogle
author_rank: Newbie
timestamp: March 11, 2014, 01:00:42 am
content: I am trying to figure the best method for detecting what type of silicon wafers I have, along with what type of coating some of them have. Most are polished rejects with tiny scratches / defects in the surface.Any suggestions / ideas?http://wtfmoogle.com/?p=3612Larger photos on my website of a few of the neat wafers.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: March 11, 2014, 04:48:35 am
content: Probe the surface (standard meter probes, make sure they're pointy enough to make contact, in case the surface is passivated or whatever). Check resistance (first to see if you are making contact, but also to get some idea of the doping -- by my understanding, light P doping is pretty common, but YMMV). Then measure voltage while holding a hot soldering iron (or other heat source) near one probe. The voltage will go positive or negative on the order of 10s of mV. Which sign the heated side exhibits determines the doping polarity. I forget which... JFGI.Tim

author: Refrigerator
author_rank: Super Contributor
timestamp: March 11, 2014, 10:16:27 am
content: You could locate the pins and maybe make a little test jig with little connectors coming down on the wafer.
Silicone glue for heatsink short circuits - Page 1
Forum section: electronics / beginners

author: LaserTazerPhaser
author_rank: Regular Contributor
timestamp: March 26, 2019, 12:26:26 am
content: Can thishttps://www.aliexpress.com/item/2Pcs-Thermal-Conductive-Heatsink-Plaster-Viscous-Compound-Glue-for-PC-GPU-88-DJA99/32886629909.htmlcause inaccuracies for 2728 shunts when gluing small heatsinks?Shunts rely on millivolts Im not sure if the rubber would conduct just enough from pad to pad to make the shunts not work properly.Is the glue not safe for contact onto pads or leads of components on the board?

author: LaserTazerPhaser
author_rank: Regular Contributor
timestamp: March 26, 2019, 12:46:49 am
content: Quote from: blueskull on March 26, 2019, 12:38:12 amHow about for components working with 12v-48v?Perhaps a chip capacitor near a switching inductors which has joining glue on its pads and the inductors pads.

author: wraper
author_rank: Unknown
timestamp: March 26, 2019, 12:48:57 am
content: The issue here is that you should not use it unless your heatsink is non conductive because this adhesive won't insulate it reliably.

author: LaserTazerPhaser
author_rank: Regular Contributor
timestamp: March 26, 2019, 01:00:51 am
content: Quote from: wraper on March 26, 2019, 12:48:57 amWorking with ceramic heatsinks. Not sure if silicone will cause shorts by itself.

author: JustMeHere
author_rank: Frequent Contributor
timestamp: March 26, 2019, 02:39:48 am
content: I recently used Gorilla Glue Silicone Sealant to provide stress relief and insulation for a thermocouple connection.I tested a bead of the sealant when it was wet. At less than 1mm separation I still read open circuit on my multi-meter resistance. I could also not get a resistance reading once it dried.It helped stabilize my thermocouple's cold junction.

author: LaserTazerPhaser
author_rank: Regular Contributor
timestamp: March 26, 2019, 04:21:23 am
content: Quote from: JustMeHere on March 26, 2019, 02:39:48 amWhat meter?Tubes tend to dry out quickly.
Silver Epoxy for Ground Paddles - Page 1
Forum section: electronics / beginners

author: krapht
author_rank: Contributor
timestamp: August 15, 2013, 01:46:16 am
content: Hello,I'm currently designing a 915 MHz oscillator. I want to use a small DFN RF amplifier in my circuit. I've never hand-soldered a part with a thermal paddle - and normally I'd just pick another part, but since this project is on my own time, I'd like to explore outside my comfort zone. I do have a hot air gun.The recommended layout has many vias to ground underneath the ground paddle. If I laid it out according to manufacturer recs, I don't think I'll ever solder the part correctly with my setup. One, the solder would wick down the vias, and two, my ground plane is an enormous heatsink.Instead, I was thinking of using silver epoxy on the ground paddle and my hot air gun to reflow the leads. Has anyone done this before? Would it work?

author: richard.cs
author_rank: Super Contributor
timestamp: August 15, 2013, 08:55:24 am
content: My suspicion is that 1) thermal and electrical contact will be pretty poor and 2) the epoxy may be damaged when you solder the rest.One way to hand-solder these is to heat the ground plane on the back with a hot plate and then solder from the front with an iron - the copper pad should extend past the end of the chip so you can get the solder to wick under onto the pad. Some people put a large plated through hole on these to hand-solder the thermal pad from behind. You may be able to get away with a hot air gun if you do it before you put other components down but I suspect you'll still need a hot plate to pre-heat the ground plane.If you haven't made the PCB yet I would strongly suggest you deviate from what the manufacturer recomends as that will be for machine assembly and you can make your life a lot easier. So long as you have a low (electical and thermal) impedance path to your groundplane it should be fine. I would suggest extending the copper on the top layer above and below the chip and one large plated hole behind the chip instead of the many vias.

author: SArepairman
author_rank: Frequent Contributor
timestamp: August 15, 2013, 06:50:53 pm
content: I read that the solder coverage area of thermal pads is not as linear as I would think, I think the difference in heat dissipation ability from 50% coverage to 100% coverage was like 20%.There might not be any need to fuss about it.
+SIM DROP problem - Page 1
Forum section: electronics / beginners

author: Kemme
author_rank: Contributor
timestamp: March 30, 2015, 05:46:38 pm
content: Hello allI've been playing around with Fibocom G510 module. I managed to connect it to my LPC1225 microcontroller and I was able send and receive text messageseverything seemed to be ok.Today, however I experienced something weird.About 10 seconds after the startup, G510 loses connection to the network (I see if it is connected or not watching the status diode). When it happens all I can do is to restart the module because it is not able to restore the connection itself.I connected it directly to my PC using ft232RL and I used putty to see what is going on. It turned out that the module sends +SIM DROP when it losses the connection.What can be the reason of that behavior? I checked the connections and everything seems to be ok. Funny thing is that "+SIM DROP" message is not mentioned in Fibocom documents. I can't even find anything on google.
SIM Interface - Extender - Page 1
Forum section: electronics / beginners

author: Tantalum
author_rank: Regular Contributor
timestamp: January 07, 2019, 09:45:17 pm
content: HelloDo you think that it is possible to build a 3m SIM card extender with twisted pair cable and high speed LVDS drivers???(I would have taken a P82B96 I2C driver, but it is specified for max 1MHz. The bus of a SIM card can go up to 5MHz)Any idea?Thanks
SiM3U1xx Programming issue. - Page 1
Forum section: electronics / beginners

author: DanioIO
author_rank: Contributor
timestamp: December 05, 2014, 06:12:14 pm
content: Hi,I recently ordered some SIM3U167 for my project, but i have a problem with programming this ic. My JTAG isnt supported by SiLabs Flasher. Is there other way to program this ic?
SIM868 - how to disable verbose/debug mode(?)  - Page 1
Forum section: electronics / beginners

author: twizzter
author_rank: Contributor
timestamp: May 05, 2024, 10:39:45 am
content: Is there an AT command or config option that will mute the module to send only the most relevant information over the UART?For example, if I send "ATI" the module returns a lot of useless information:Code:1958-01-01 11:02:46[uart.c:43 event_uart_ready_rd]uart 0 recv: ATImodem recv: ATISIM868 R14.180Plus the console throws randomly:Code:1958-01-01 11:08:55[socket.c:236 bear_notify_cb]bear_notify state: CBM_DEACTIVATED.1958-01-01 11:09:00[event.c:70 event_timer]timer TIMER_MAIN_LOOP happened.1958-01-01 11:09:00[gps_utils.c:177 gps_getGPS]gps status NOT FIXED, please wait GPS fixed!: 11958-01-01 11:09:05[event.c:70 event_timer]timer TIMER_MAIN_LOOP happened.1958-01-01 11:09:05[gps_utils.c:177 gps_getGPS]gps status NOT FIXED, please wait GPS fixed!: 1Not sure if it's important, but module was bought as an evaluation board from Ali.It turned out that module's sticker has been covered with a new one having different IMEI. I guess recycled component? Beta/buggy/improper firmware maybe?

author: bookaboo
author_rank: Frequent Contributor
timestamp: May 05, 2024, 11:31:59 am
content: That second output log doesn't look like SIM8xx output. Is there a secondary controller inbetween?

author: twizzter
author_rank: Contributor
timestamp: May 05, 2024, 12:40:37 pm
content: I'm hooked up to the module's UART1. Attached a photo of PCB and a schematic for reference.

author: bookaboo
author_rank: Frequent Contributor
timestamp: May 06, 2024, 06:17:10 am
content: It's a while since I used SIM868 but I don't recall the output being so verbose.There is a command ATV that relates to the response format, you an also turn off echo with ATE.You will have to write a parser anyway, so you will become very familiar with the command set:https://wiki.elecrow.com/images/2/20/SIM800_Series_AT_Command_Manual_V1.09.pdfOne other point, SIM868 is 2G only, which will be sunset pretty much everywhere in 5-10 years, perhaps sooner in some regions, already done in some. It might be better to learn how to work with an NB-IoT or CATM module.
SIM900A, CIICR error: +PDP DEACT - Page 1
Forum section: electronics / beginners

author: A2
author_rank: Contributor
timestamp: September 24, 2014, 12:36:02 pm
content: 1. I have one local sim & tried to interface SIM900A module with microcontroller, without any problem. I am able to send data over TCP.2. I have a number sim from other state/region, i.e roaming in my region, when I tried to send AT+CIICR command SIM900A module respond with error: +PDP Deact.Anyone knows the solution?

author: A2
author_rank: Contributor
timestamp: September 25, 2014, 06:37:03 am
content: any help om that,Local sim works fine, while sim which is in roaming does not work & gives error
Sim900A cipsend fail if used continuously - Page 1
Forum section: electronics / beginners

author: A2
author_rank: Contributor
timestamp: September 25, 2014, 05:03:20 pm
content: I have configured sim900a module to send data over tcp/ip.First few time I am able to send data by AT+CIPSEND, then I get ''>" reply & enter the data & then 0x1A.After that I got "SEND OK" from module.But then after some continuous successes it fails. First it stop send "SEND ok" & then sometimes module don't send ">"1. Frequency of success & failure vary everytime.2. I call CIPSEND every 5 sec & send 10 bytes of data everytime.

author: Rerouter
author_rank: Super Contributor
timestamp: September 30, 2014, 08:26:29 am
content: while i dont own your modem, have a close look at what data was sent prior to it playing up, i've had a few issues where a pattern used to define end of a large chunk of data on my device matched a factory setup code which then bricked the device until a power cycle,
SIM900A module email send - Page 1
Forum section: electronics / beginners

author: Vindhyachal.takniki
author_rank: Frequent Contributor
timestamp: October 21, 2015, 03:25:25 pm
content: 1. I am using SIM900A to send email. My code sequence is below.2. Baud is 9600 & internet on SIM works ok.3. All commands sequence ok response from SIM900A, but when I send the email I got error "SMTPSEND: 67" or "SMTPSEND: 61", correspond to authentication failed or network error.4. Below is code:->AT<-OK->AT+SAPBR=3,1,"CONTYPE","GPRS"<-OK->AT+SAPBR=3,1,"APN","TATA.DOCOMO.INTERNET"<-OK->AT+SAPBR=3,1,"USER",""<-OK->AT+SAPBR=3,1,"PWD",""<-OK->AT+SAPBR=1,1<-OK->AT+SAPBR=2,1<- +SAPBR: 1,1,"xxx.xxx.xxx.xxx" //IP<-OK->AT+EMAILCID=1<-OK->AT+EMAILTO=30<-OK->AT+EMAILSSL=1<-OK->AT+SMTPSRV="smtp.mail.yahoo.com",465<-OK->AT+SMTPAUTH=1,"sender_id_xxxx@yahoo.in","password" //sender email username & passwordOK->at+smtpfrom="sender_id_xxxx@yahoo.in","name" //sender email username & id<-OK->at+smtprcpt=0,0,"rx_id_xxxx@gmail.com","name" //rx id & his name<-OK->at+smtpsub="test"<-OK->AT+SMTPBODY<- > THIS IS TEST (ctrl+z)<-OK->AT+SMTPSEND<-OK<- +SMTPSEND: 61

author: krish2487
author_rank: Frequent Contributor
timestamp: October 21, 2015, 07:00:21 pm
content: Again,Googling for the error code you have pasted leads me to thishttps://forum.arduino.cc/index.php?topic=354657.0Please stick one or two forums where you feel you can identify with and don't spam across google. It is not good net etiquette.Please provide details - hardware, schematics, bring up procedure, micro, compiler, your complete code and error combo.The more sensible information you provide, the better chance folks here have of helping you.Help us, help you.I am an indian myself, and I can sympathise with the overwhelming blockade you feel you are having. But please, this is not a place where others willhand hold you to the point of spoon-feeding you. You have to show what you have done to even illicit a response. Presenting a part of the puzzle and expecting a complete response, magically, is not realistic.I hope I have not come across as rude, I apologise if I do.

author: picandmix
author_rank: Frequent Contributor
timestamp: October 21, 2015, 08:23:12 pm
content: The Sim900A is said to be locked to certain far east countries, are you in a suitable country ?If not you have to reprogram its firmware with the Sim900 version.This link lists the areas coveredhttp://www.blog.zapro.dk/?p=368
SIM900A, server listening problem - Page 1
Forum section: electronics / beginners

author: Vindhyachal.takniki
author_rank: Frequent Contributor
timestamp: October 16, 2015, 12:09:42 pm
content: I am using SIm900A module to get data by maing it as s server.Below is code.baud is 9600.-> Input to SIM900<- output from SIM9002. I have SIM900A connected to PC via RS232 cable. Using realterm to send commands.Also for client my using Herculus TCp software, in which i select TCP client option & fill ip address of SIm900A received after AT+CIFSR command & port to which I have to connect.3. Problem is SIm900A start listening, but when I tried to connect by Herculus TCP, it get failed to connect everytime.My PC is connected to broadband connections.I am able to GET google page using SIm900a, that means internet is working on SIM inside sim900A->AT<-OKdelay_sec(3);->AT+CPIN?<-CPIN: READYdelay_sec(3);->AT+CREG?<-+CREG: 0,1delay_sec(3);->AT+CIPSHUT<-SHUT OKdelay_sec(3);->AT+CIPMUX = 0<-OKdelay_sec(3);->AT+CGATT=1<-OKdelay_sec(3);->AT+CGDCONT=1,"IP","TATA.DOCOMO.INTERNET"<-OKdelay_sec(3);->AT+CSTT="TATA.DOCOMO.INTERNET","",""<-OKdelay_sec(3);->AT+CIICR<-OKdelay_sec(3);->AT+CIFSR<-xxx.xxx.xxx.xxx //ip addressdelay_sec(3);->AT+CIPSERVER =1 ,1234<-OK<-SEREVR OKdelay_sec(3);->AT+CIPSTATUS<-OK<-STATE: SERVER LISTENINGdelay_sec(3);// now SIM900a start to listen, but herculus tcp failed to make connection.
sim900a tcp GET, not working - Page 1
Forum section: electronics / beginners

author: Vindhyachal.takniki
author_rank: Frequent Contributor
timestamp: October 15, 2015, 01:49:45 pm
content: I am using SIm900A module to get data using cipsend command.I don't receiving anything agter GET command. below is code.baud is 9600.-> Input to SIM900<- output from SIM9002. I have SIM900A connected to PC via RS232 cable. Using realterm to send commands. (also tried hyperterminal)3. I have put sim in mobile & checked internet is working on it.->AT<-OKdelay_sec(3);->AT+CPIN?<-CPIN: READYdelay_sec(3);->AT+CREG?<-+CREG: 0,1delay_sec(3);->AT+CIPSHUT<-SHUT OKdelay_sec(3);->AT+CIPMUX = 0<-OKdelay_sec(3);->AT+CGATT=1<-OKdelay_sec(3);->AT+CGDCONT=1,"IP","TATA.DOCOMO.INTERNET"<-OKdelay_sec(3);->AT+CSTT="TATA.DOCOMO.INTERNET","",""<-OKdelay_sec(3);->AT+CIICR<-OKdelay_sec(3);->AT+CIFSR<-xxx.xxx.xxx.xxx //ip addressdelay_sec(3);->AT+CIPSTART="TCP","www.google.com","80"<-OK<-CONNECT OKdelay_sec(3);->AT+CIPSEND<- >-> GET / HTTP/1.1 //IN SAME LINE ABOVE-> Host:www.google.com-> Ctrl+z<- SEND OK<- CLOSED //after long delay<-+PDP: DEACT //after very long delay

author: kfitch42
author_rank: Frequent Contributor
timestamp: October 15, 2015, 02:27:03 pm
content: I am not familiar with this SIM900a thingy, but I have dealt HTTP a bit. The first thing that jumps out at me is that I don't see the extra newline after the header lines are finished. To be exact the string that should be sent to the web server should be (expressed in normal C string notation):"GET / HTTP/1.1\r\nHost:www.google.com\r\n\r\n"You should even be able to get away with:"GET / HTTP/1.0\r\n\r\n"I haven't tried, but I would assume a lenient web server might be OK with something as simple as"GET / HTTP/1.0\n\n"or maybe even"GET /\n\n"

author: Vindhyachal.takniki
author_rank: Frequent Contributor
timestamp: October 16, 2015, 11:05:28 am
content: @kfitch42, that was exactly the problem.
Simple LiPo cell charger? - Page 1
Forum section: electronics / beginners

author: makebit
author_rank: Unknown
timestamp: October 08, 2025, 10:36:10 am
content: Hi,We want a very simple LiPo cell charger.LiPo cell is 3.7V (3.2-4.2V)Vin = 5VWe want to charge the cell at 1.25A till it gets up to 4.2V, then stop charging.We dont want any USB connection or anything like that communicating with the chip. If it has that , then we need to disable it.We've been searching the web for the last two hours for a chip that does this, but to no avail.We could do it with eg a SEPIC and an external current monitor etc, etc......but customer wants just one chip that does it as they have very little board space.Just been looking at BQ25628E, but it needs USB control to do what we want.

author: ftg
author_rank: Frequent Contributor
timestamp: October 08, 2025, 12:51:52 pm
content: TDSEMI and HICHON have TP4056 versions that do nominal 1.2A charging current instead of the more usual 1A.Fine Made's FM4258 is a switcher if you don't like heat from a linear one.And INJOINIC's IP2332 only requires a coil, no external diodes or fets required.Plenty of others here as well:https://www.lcsc.com/category/1005.htmlKainda surprising that you have not found many, considering that this is the most common LiPo charging scenario.
Simple 3.3v (FPGA) to 12v mechanism shorted my PCB - Page 1
Forum section: electronics / beginners

author: namlu
author_rank: Contributor
timestamp: September 03, 2015, 03:39:07 am
content: Hello.This is what I done in order to make 12v discrete, capable of 1A current.Never used this FPGA pin (was always '0'). PCB was used for less then 5 hours total, for other uses, and then stopped working. Short circuit caused by the 3 transistors circuit in the picture (I guessed it's them because of brown color around. Desoldered them, and PCB started working again).Any idea what could it be? Have I done anything wrong? Could it be just bad luck (small conductor flew on top of the PCB and shorted some of the pins, etc...).Thank you.Sent from my iPhone using Tapatalk

author: tggzzz
author_rank: Super Contributor
timestamp: September 03, 2015, 07:37:52 am
content: Consider the voltage at Q23's drain, both when the input signal switches and when the power supply is turned off and on. You will probably find that for some time Q24 and Q25 were turned on simultaneously.

author: SaabFAN
author_rank: Frequent Contributor
timestamp: September 03, 2015, 04:37:09 pm
content: Its most likely due to the fact that Q23 did not receive enough voltage to reduce its resistance enough to pull down the voltage enough to stop Q24 from conducting. Most MOSFETs start conducting at around 2V, but require something around or above 5V to reach their lowest resistance. Datasheet should provide a Vgs/Rds Curve.To ensure good voltages with fast switching-times for the output-stage, I suggest an additional inverter-stage to provide +12V to Q23.Or use 2 opto-couplers instead of Q23 and R390 in a similar bridge-configuration as Q24 and Q25. If you connect them in series to a 3.3V-Rail and connect the FPGA-Pin in the "middle", you should be able to turn one on completely, while the other one is switched off entirely. The FPGA-Pin has to be able to source and sink about up to 5mA though.I'd prefer the Opto-Coupler Method btw. Makes it impossible to blow up the FPGA in case a voltage-spike on the 12V-Rail, caused by an inductive load exceeds the isolation-capability of the MOSFET-Gates.
simple 555 pwm generator problem - Page 1
Forum section: electronics / beginners

author: m.m.m
author_rank: Regular Contributor
timestamp: April 16, 2015, 03:12:36 pm
content: Hi everybody, I wanted to make a simple pwm generator with the 555 IC.I tried this schematic on the breadboard:http://www.dprg.org/tutorials/2005-11a/but the output is constant 12v and the pin 7 voltage is about 6v constant. what have I put wrong?thanks.edit:there are also some schematics that use the pin 3 as input for the mosfet and connect pin7 to the potentiometer, which one should I use?

author: m.m.m
author_rank: Regular Contributor
timestamp: April 16, 2015, 07:16:48 pm
content: solved, It turned out that two of my 555s have been damaged and don't work. used a 7555 and worked great.
Simple 555 timer question (I hope) - Page 1
Forum section: electronics / beginners

author: Cubbie
author_rank: Contributor
timestamp: August 22, 2021, 07:30:10 pm
content: I'm using this delay before turn on timer circuit which works great but, I would like the output (pin 3) to only stay high for about .25 seconds. In this configuration it stays high until there is a reset. Is there something I can do with pin 7 or maybe even a R/C circuit on pin 4? Thank you.

author: Ian.M
author_rank: Super Contributor
timestamp: August 22, 2021, 08:41:22 pm
content: A 555 draws far too much current when switching for a RC ciruit on its Vcc pin to do anything useful. Your best option is two 555 circuits, one for the power on delay triggering the other to provide a 250ms pulse, but if you are willing to carefully match RC delays, it is possible to get a single one to produce a pulse like that.The problem is you cant get capacitors with a close enough tolerance in large enough values. The time constant C2.R3 needs to be longer than that of C1.R1 by your desired output pulse width. If its shorter the circuit will oscillate at a high frequency. Also the leakage current of electrolytic capacitors will mess up the timing so you need to use good quality tantalums or hi-K ceramics, then mess with the value of R3 till you get the desired result. R4,C4 provide a reset to the 555 - it *may* work without them.Don't use this circuit for anything serious - its an unreliable pile of cr@p!LTspicesim attached.

author: Cubbie
author_rank: Contributor
timestamp: August 23, 2021, 07:28:48 am
content: Thanks Ian, I will give that a try because the .25 pulse number is not critical. It can be quite a bit longer for my purpose.

author: brucehoult
author_rank: Super Contributor
timestamp: August 23, 2021, 09:06:02 am
content: It's fun playing with 555s and all, but a low end 8 pin AVR ATTiny or PIC costs less than a 555 (let along all those discrete external components!), doesn't need any external components, and can do a nearly perfectly precise job of this (or anything else a 555 can do) with a few lines of code.

author: Terry Bites
author_rank: Super Contributor
timestamp: August 23, 2021, 05:46:11 pm
content: A cmos 555 (7555) will draw less power and allows much smaller and more accurate timing capacitors to be used. You dont need expensive tantalum, just cheaper film or NPO ceramics with much tighter tolerances for your cash. I think what you want is a monostable that triggers at power up.R1 and C1 cause brief rising edge at power up triggering the mono. The pulse ends after Rt.Ct seconds. The output will then stay low indefinitely until the next power up.OoPs Vp is the output not the pint shown!
simple 74hc inverter not working in ltspice - Page 1
Forum section: electronics / beginners

author: julian1
author_rank: Frequent Contributor
timestamp: August 23, 2022, 12:22:43 pm
content: I cannot get a simple ltspice 74hc04, or 74hc14 inverter to output an inverted waveform.More complicated models such as 74hc74 flip/flop appear Ok.

author: Ian.M
author_rank: Super Contributor
timestamp: August 23, 2022, 12:44:40 pm
content: Increase 'DRIVE' logic high voltage to min. 70% of Vcc to meet 74HC family input thresholds!Code:PULSE(0 5 1us 10ns 10ns 25us 50us 7)

author: julian1
author_rank: Frequent Contributor
timestamp: August 23, 2022, 12:52:47 pm
content: I can't believe I did that. Thank you!

author: Ian.M
author_rank: Super Contributor
timestamp: August 23, 2022, 12:58:20 pm
content: Its a frequent trap for young players in the real world as well. When trying to interface a 3.3V MCU output to 5V logic, 70% of 5V Vcc is 3.5V, so if using 74HC its pure luck whether or not it works!!
Simple AC PSU for a rareish keyboard.  - Page 1
Forum section: electronics / beginners

author: Sebzy
author_rank: Contributor
timestamp: April 01, 2013, 04:28:38 pm
content: Have an old Miracle Piano minus the PSU so I'm going to make one up.http://en.wikipedia.org/wiki/Miracle_Piano_Teaching_SystemApparently it's 12VAC@1A but I'm reluctant to just plug it directly into a transformer. What could I do to put a bit of protection into the circuit?A simple schematic would be fantastic.

author: c4757p
author_rank: Super Contributor
timestamp: April 01, 2013, 04:57:19 pm
content: 1.5A fuse.

author: Sebzy
author_rank: Contributor
timestamp: April 01, 2013, 05:42:13 pm
content: Quote from: c4757p on April 01, 2013, 04:57:19 pmLOL yea thought somebody would say thatLooking for something along the lines of a MOV (Metal-oxide varistor) solution.

author: c4757p
author_rank: Super Contributor
timestamp: April 01, 2013, 05:45:24 pm
content: Er... then a MOV. Sounds like you already know what you need.

author: Sebzy
author_rank: Contributor
timestamp: April 01, 2013, 06:30:08 pm
content: Just to be clear I'm asking for advice on how to implement protection into an AC-AC power supply to be used audio equipment.I have looked at using a MOV but there seems to be quite a few different ways of using them and my knowledge on protection is not extensive so I'm throwing this out to the EEVBlog community asking for help in finding a finding a solution.The solution may be as simple as just using one MOV across the primary of the transformer or several as seen in the image attached. Basically I want to know what my options are.

author: SeanB
author_rank: Super Contributor
timestamp: April 01, 2013, 06:44:09 pm
content: 12 VAC MOV and a 1.5A thermal circuit breaker. MOV starts to conduct at around 20V peak and will trip the breaker in under 5 seconds. All this on secondaryMains rated MOV on mains input. Place a fuse there as well, slow blow.
Simple and cheap boost converter [Need help] - Page 1
Forum section: electronics / beginners

author: senso
author_rank: Frequent Contributor
timestamp: May 24, 2012, 03:30:40 am
content: Goodnight, I'm in the means of designing and creating a very cheap robot that will be used in a series of presentations that me and some friends of mine will make, so the cheaper the robot the best!I'm facing a problem with the power supply, it will be made of 4 AA batteries so the voltage can swing from 6v to 4v, assuming non rechargeable batteries are used, and I would like to boost that voltage to 7V, because the H bridge drops about 1v and the motors are rated to 6v maximum, so that and the PWM will protect the motors as they will never or very rarely be driven full speed, and then the most probable thing to happen is that the voltage will sag/drop.I have re-discovered Dave video about the MC34063 IC, and it seemed perfect, but the motors need 2A, well in fact its 1A stall current for each one, but I prefer to stay on the safe side and design the boost regulator to be able to put out the 2A, as there are also current spikes when starting the motors and so on.So, if anyone could help me, is if the MC34063 with an external "pass" transistor is a good choice or should I choose another boost converter? The greatest problem is that not all the most typical ones accept voltages as low as 4v, and those that accept them are way to expensive, like the MC is 44 cents in Mouser, a single LM2677 is more than 3€.Any ideas, tips, links to read, I'm open to it, and thanks in advance to any help provided

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: May 24, 2012, 07:47:54 am
content: MC34063 is very cheap but pretty rubbish as DC/DC's go. There are plenty to choose from, and unit cost is not going to be a big part of the cost if you're only building a few, so something that's a good fit will probably save you more in time and ancillary parts cost than the difference in unit cost.
Simple audio mixer - splitting mono, avoiding noise - Page 1
Forum section: electronics / beginners

author: fsky
author_rank: Contributor
timestamp: February 02, 2016, 09:08:52 pm
content: Hello!I'm trying to design basic audio mixer. Right now, as shown in the schematic, it should provide a mono input,with optional microphone (electret type) bias and optional +20dB gain switch (+highpass switch, but I didn't figured it out yet).My main question is - how to mix mono op-amp buffered output onto both left and right channels, with adjustable balance?My current approach shown in the schematic, with potentiometer, doesn't work in simulation - both channels are at the same levelon the left/right channels output.My second question is about microphone input ac-coupling. Previously I've put capacitor after the potentiometer, but then I rememberedthat DC current from bias circuit flowing trough pot could create a noise problem. So I've placed the cap before it. Is it OK?Will that change anything in terms of bandwidth?Third question is about input noise with disconnected input. I've tested the circuit of U8A/U10A opamp alone (responsible for right/left channelamplification). With input disconnected, amplitude of noise depends on potentiometer setting - which is counter-intuitive for me, as no DC current should pass trough it. I checked that noise on oscilloscope, and there was a lot of very low frequency noise. Any lecture on that?Question on the side - can I import PSpice schematics to the Eagle?I've made some research on the forum before posting this, but nothing was particularly helpful. Anyway, if anyone with similar problemwill search here, I'm putting links to topics found:https://www.eevblog.com/forum/projects/audio-amp-question/https://www.eevblog.com/forum/projects/sanity-check-on-my-first-project/In case anybody asked, my supply is symmetrical 5V.Please point out my mistakes and provide any advice.Looking forward to your replies, have a good day!Edit:I've noticed my mistake - by accident I've joined output channels into one node, that's why it wasn't working.Uploaded corrected schematic. Still I don't know if my solution is a good one, so please comment

author: mikerj
author_rank: Super Contributor
timestamp: February 02, 2016, 09:21:06 pm
content: Try something like this. I leave the resistor value calculations to you
Simple battery management - Page 1
Forum section: electronics / beginners

author: scrat
author_rank: Frequent Contributor
timestamp: March 04, 2011, 03:08:21 am
content: Hi all,I'm after a small accelerometer acquisition board which needs to be powered at 3.6V in turn from USB or a battery.Since I'd like to use a rechargeable battery and the tiny cell phone ones are quite cheap, I was planning to use a Li-ion battery, and to manage on the board the charging from USB power.I see many management ICs, but they seem too complex for what I need: when USB power is present and battery discharged/not connected, then charge the battery and/or power the rest of the board, if there is only the battery, use its power for the system.Is it really too much to ask for having all of this in a single (and simple!) IC, making voltage regulation at the same time?I think this is a really common issue.

author: Zyvek
author_rank: Regular Contributor
timestamp: March 04, 2011, 03:18:06 am
content: Check this out, I just found it inside a cheap 18650 li-ion battery charger.

author: Strube09
author_rank: Regular Contributor
timestamp: March 04, 2011, 01:05:48 pm
content: Scrat,Lets just say I know quite a bit about battery electronics... and there are quite a few option for you. Not sure how excited you are about a DFN package but check out LTC4067 from linear tech.... I think it is exactly what you need.Strube

author: scrat
author_rank: Frequent Contributor
timestamp: March 07, 2011, 11:22:41 am
content: Thanks Strube fo the reply!The only thing that I would have asked more was a less small package (the powerpad is always a trouble, but I see almost all of the linear battery chargers have one) and a regulator (but I see none of this devices having an output regulator).I'll evaluate a little bit more some of the similar options from Linear and TI, but yours is a good candidate.

author: scrat
author_rank: Frequent Contributor
timestamp: March 28, 2011, 11:35:32 pm
content: Quote from: Zyvek on March 04, 2011, 03:18:06 amExcume if I didn't add any comment. As from the datasheet, it is an isolated switching converter driver. It doesn't fit the need, although it can be used (as you say) as part of a battery charger.What I was looking for was a tiny IC regulating a small amount of power, to be embedded into a small board ad a charge controller.I ended choosing MAX1551 from Maxim, which is one of the few (to be honest, the only) coming in a usable package and being imple. Unfortunately, it lacks of a shut down/charge current control pin, but I think that it will be enough for my board.
Simple boost converter - differences between reality and LTSpice - Page 1
Forum section: electronics / beginners

author: Momchilo
author_rank: Regular Contributor
timestamp: April 30, 2017, 11:04:46 pm
content: Hello,I built a very simple boost converter on a breadboard and measured the output voltage across the capacitor without a load.The measured output voltage is 6.2V and the input voltage is 3V (see figure).I simulated this circuit in LTSpice with the same parts (standard lib) but the output voltage is only 4.5V.Any ideas what I have to change in LTSpice to get the 6.2V?Thanks for your help.Best regardsMomchilo

author: ebclr
author_rank: Super Contributor
timestamp: April 30, 2017, 11:07:22 pm
content: The inductor is a key component, try change there

author: Momchilo
author_rank: Regular Contributor
timestamp: May 01, 2017, 01:24:55 am
content: Thank you for the hint ebclr. I calculated the inductance of the used coil over the frequency with a scope and a voltage divider (I don't own a RLC meter) and the result is L=53.6µH. According to the Chinese manufacturer the inductance should be 33µHWith the new value the output voltage in the simulation is the same as in the reality.
Simple circuit (How is it working)? - Page 1
Forum section: electronics / beginners

author: BRetonDP
author_rank: Contributor
timestamp: April 09, 2014, 05:21:29 am
content: Hello everyone!Even though I think I understand how they work, I don't have a lot of experience with transistors (let alone PNP). This little circuit is supposed to make the two LED's blink in an alternating pattern, but I can't get my head around 'why' this is happening. Would someone be kind enough to briefly explain the current flow in this the schematic to me?The circuit belongs to a MAKE Magazine video.

author: Kappes Buur
author_rank: Regular Contributor
timestamp: April 09, 2014, 05:54:09 am
content: Perhaps with the circuit redrawn it makes more sense:

author: FrankBuss
author_rank: Unknown
timestamp: April 09, 2014, 06:24:36 am
content: It's an astable multivibrator. Good explanation on Wikipedia:http://en.wikipedia.org/wiki/Multivibrator#Astable_multivibratorThe concept is the same with PNP and NPN transistors.

author: ludzinc
author_rank: Unknown
timestamp: April 09, 2014, 06:48:31 am
content: There's a small caveat to applying standard circuit analysis here.If you assume all the parts are ideal, when you apply power, NOTHING happens. Indeed if you try to simulate it in spice, it will fail to oscillate.In real life there are small differences that will allow one side to charge slightly faster than the other and the circuit will soon oscillate.

author: EEVblog
author_rank: Unknown
timestamp: April 09, 2014, 07:01:45 am
content: Here you go:http://www.talkingelectronics.com/projects/BasicElectronics-1A/BasicElectronics-1A_Page5.htmlSame thing but using NPN's.

author: GK
author_rank: Super Contributor
timestamp: April 09, 2014, 07:09:08 am
content: Quote from: ludzinc on April 09, 2014, 06:48:31 amThis circuit is prone to lock-up (both transistors staying on) if the supply voltage initially ramps up slow enough.And a common design error is to not realise that the b-e junctions of the transistors will be alternately reverse biased by almost the full supply voltage when the circuit is oscillating. Most small-signal transistors can tollerate -5V Vb-e max. Zenering the b-e junctions in the long term causes irreversable damage (hfe degredation) to the transistors. The simplest fix is to put a 1N914 in series with each emitter.

author: BRetonDP
author_rank: Contributor
timestamp: April 10, 2014, 01:10:29 am
content: Thank you for your responsesWhile I understand the concept, I'm having problems, as FrankBuss stated, understanding why this circuit doesn't saturate both transistors and always stays on. That's why I wanted to know the current flow. Is it only because of a physical characteristic of the circuit, then? No deeper science?

author: BRetonDP
author_rank: Contributor
timestamp: April 10, 2014, 01:12:59 am
content: Quote from: GK on April 09, 2014, 07:09:08 amAlso, what does it mean to be reverse biased?