hybridfree/eevblog-posts huggingface dataset:
E² Pot? E-squared potentiometer? - EEV Blog #221 Doubt - Page 1
Forum section: electronics / beginners

author: japasetelagoas
author_rank: Regular Contributor
timestamp: November 19, 2016, 03:25:11 pm
content: Hey everyone,I'm here taking my notes based on Dave's out of this world knowledge but I stumbled upon a sentence that I couldn't make sense of.At around 14:20 minutes he says:"Well you could get like anE squared potor something like that. You're going to watch your maximum voltages, a lot of those, it'll only go up to 6 or, ya know, getting ones that go up 12 volts are quite rare..."Could someone explain to me what is this E squared pot? I tried searching the web and all I got was some sort of SMD type potentiometer. I also thought about being a simple logarithmic pot but once again, I'm not really sure.Any help would be much appreciated.Thanks.Link to his video:

author: rstofer
author_rank: Super Contributor
timestamp: November 19, 2016, 03:56:18 pm
content: Probably a digital pot like the Xicor X9315 E2POTtmNonvolatile Digital Potentiometerhttp://www.icbase.com/File/PDF/XIC/XIC00870106.pdf

author: Kleinstein
author_rank: Super Contributor
timestamp: November 19, 2016, 04:00:55 pm
content: I don't know E - squared pots either. My guess would be a digital pot. A few have EEPROM (sometimes called E²Prom) to keep old setting. But anyway it does not work for the current shunt anyway, as those are available for a limited range (e.g. 5 K - 1 M) only. So it would be something for the µA range.Anyway this video is more on how not to build an lab supply. It shows some of the problems, but no working solution.
TAB bonding machine - Page 1
Forum section: electronics / beginners

author: Jane
author_rank: Frequent Contributor
timestamp: August 04, 2015, 10:32:21 am
content: Does anyone know what kind of heating pulse TAB bonding machines use?If induction heating or resist or different?Thank you

author: Fraser
author_rank: Super Contributor
timestamp: August 04, 2015, 11:13:24 am
content: Inter metal junction Resistance.I have such a unit for battery tab welding.Aurora

author: amyk
author_rank: Super Contributor
timestamp: August 04, 2015, 12:11:15 pm
content: Quote from: Aurora on August 04, 2015, 11:13:24 amI think you've confused battery tabs withTape Automated Bondingas commonly used for LCD controller mounting. More discussion here:https://www.eevblog.com/forum/chat/diy-hotbar-bonding-machine/

author: fcb
author_rank: Super Contributor
timestamp: August 04, 2015, 12:37:16 pm
content: Another name is: "hot bar", you might able to glean more from that search term.

author: EEVblog
author_rank: Unknown
timestamp: August 04, 2015, 12:43:32 pm
content: Quote from: fcb on August 04, 2015, 12:37:16 pmYes, I know them as "hot bar" machines.

author: Jane
author_rank: Frequent Contributor
timestamp: August 04, 2015, 02:02:45 pm
content: Yes, I would like know what kind of heating is used for hot bar machine that is used for LCD controller mounting, flex mounting to PCB etc.Thanks

author: Shock
author_rank: Super Contributor
timestamp: August 04, 2015, 03:07:22 pm
content: Quote from: Jane on August 04, 2015, 02:02:45 pmA quick look showed one brand as using a thermode, and hot air probably to keep surface temp consistent. I've seen a video showing the main heating at 200C with 2.5Mpa pressure for 25s.

author: Jane
author_rank: Frequent Contributor
timestamp: August 05, 2015, 09:27:54 am
content: @Shock:Do you have a link to the video?
table lookup problem (pic18f) - Page 1
Forum section: electronics / beginners

author: Lesterwyatt
author_rank: Regular Contributor
timestamp: January 05, 2015, 04:03:17 pm
content: Hello.i have implemented a lookup table for my nokia lcd project. the lookup table consists of bitmap data (7 byte for each character 'see below'). what i need to do is select and display a character based on a BCD value. So for instance; if i had a unpacked BCD value of 00000010 this value would select entry number '2' in my table data and return with it for display. As it stands, what ever value i throw at my table it displays all of the data on the LCD .i.e. 1234567890.many thanks Lesterpart of my code below:NEXT movlw high MY_DATA ; load font1 H address to tbptrHmovwf TBLPTRHmovlw upper MY_DATA ; load font1 U addressmovwf TBLPTRUmovlw low MY_DATA ; load font1 L address to tbptrLmovwf TBLPTRLmovf TEMP ,Waddwf TBLPTRLtblrd *+ ;read table entry into TABLATmovf TABLAT,w ;in WREGcall SPI ; get data and write outincf TEMPMOVLW -.2CPFSEQ TEMPgoto NEXTRETURNORG 0x500MY_DATAdb 0x3E,0x7F,0x71,0x59,0x4D,0x7F,0x3E,0 ; '0'db 0x40,0x42,0x7F,0x7F,0x40,0x40,0x00,0 ; '1'db 0x62,0x73,0x59,0x49,0x6F,0x66,0x00,0 ; '2'db 0x22,0x63,0x49,0x49,0x7F,0x36,0x00,0 ; '3'db 0x18,0x1C,0x16,0x53,0x7F,0x7F,0x50,0 ; '4'db 0x27,0x67,0x45,0x45,0x7D,0x39,0x00,0 ; '5'db 0x3C,0x7E,0x4B,0x49,0x79,0x30,0x00,0 ; '6'db 0x03,0x03,0x71,0x79,0x0F,0x07,0x00,0 ; '7'db 0x36,0x7F,0x49,0x49,0x7F,0x36,0x00,0 ; '8'db 0x06,0x4F,0x49,0x69,0x3F,0x1E,0x00,0 ; '9'END
Tachometer design for small engines? - Page 1
Forum section: electronics / beginners

author: larrybl
author_rank: Regular Contributor
timestamp: July 17, 2016, 01:23:58 am
content: This may be a simple matter-or not, but I have not found a good solution to a problem I have, and as a member of several Tractor sites no one there has a good solution either. The machines that I restore run optimally at 3600 rpm, and setting the rpm is challenging. What I need is a Tachometer that can be installed on the dash and 1. Looks good in/on the dash (dash pictures attached), and is weather proof. 2. Simple to hook up. 3. Works off 12-14 vdc WITHOUT an internal battery. 4. Will need some sort of mechanical or spark pickup as some machines are twin cylinders, some single, Also some use points and coil, and others use electronic ignitions.I have looked at the tinytachhttps://www.amazon.com/Tiny-Tach-Digital-Tachometer-Meter/dp/B007YH2AH8/ref=sr_1_4?ie=UTF8&qid=1468713750&sr=8-4&keywords=tiny+tachand it seems the internal battery is less than desired.I use this to set the initial Governed setting at 3600 rpm, but there is no way to monitor actual rpm when the machine is in use.http://www.harborfreight.com/digital-photo-sensor-tachometer-66632.htmlI am capable of assembling discrete components. I guess I am looking for a display that can be stuck to the dash, some sort on counter that can display revolutions, and some sort of mechanical / optical pickup that can be added to the flywheel or drive pulley on these machines.I am not against some sort of “spark sensor” as the tinytach uses.I have some electronic experience and can assemble discrete components. I have converted several of these machines to use LED lamps, Including one that requires 28 vdc which I taped the 30 vac stator to obtain.Just looking for options or suggestions.Pictures of the machines that I am talking about.1978 Roper 20T1988 Craftsman II1990 Craftsman198? John Deer (In the works)Any suggestions?

author: tautech
author_rank: Super Contributor
timestamp: July 17, 2016, 02:13:42 am
content: In another life I serviced small motors and tachos ever since have been of interest. AFAIK currently the best portable unit for use as service/tuning/setting max revs aid is the Husqvarna digital RF unit, but oh the price.For setting max revs something that is fast to give a reading is best, and a non-contact RF or inductive pickup is best.There are a few on Aliexpress, some quite well priced that might be worthy of consideration however a different brand that I got was very slow to measure max revs in chainsaws that run to 13K RPM.This seller has a good range and models for 2 & 4 stroke, 1 & 2 cyl engineshttp://www.aliexpress.com/store/526329?spm=2114.10010108.100005.4.LjsOsu

author: Seekonk
author_rank: Super Contributor
timestamp: July 17, 2016, 11:32:51 am
content: I got a friend a couple $12 US ship ones that look the same as the Tiny for his gocarts. He loves them.
Tact switches + rotary switches + multiplexer logic failure help - Page 1
Forum section: electronics / beginners

author: cincin
author_rank: Regular Contributor
timestamp: April 14, 2024, 03:58:43 am
content: I'm working on a MiroKORG digital synthesizer, and the only problem left is that the TECHNO rotary switch selection, the Program 2 and Bank A/B tact switches do not work. Pressing the tact switch, or rotating the switch to TECHNO, has no effect.Looking at theschematics (page 9), you can see that the 2nd pole (labeled #3) of the BANK SELECT rotary switch (SW2) is on the same line as the Bank Select A/B tact switch (SW5), and Program 2 (SW12). I suspect the second pole on SW3 and SW8 (labeled #3) also don't work, I haven't tested them specifically.I looked at the traces and there's strong continuity from pole 2 of SW8 all the way to pin 69 of IC18 (on page 6 of the service manual, following T1).D14 and D20 test fine (page 9), C186 and L30 (page 6) also seem fine.I've replaced the tact switches and cleaned the rotary switches contacts before realizing that wasn't the problem. All switches test fine.And that's where I'm lost.If it was a problem with the multiplexer (IC22, page 9) I would expect more than those buttons to give unexpected results, but I admittedly don't know what I'm talking about (that's why I'm in Beginner)But what else could it be? a logic failure in IC18 (CPU)?What should be my next troubleshooting step, swap the multiplexer?Thanks!

author: Kim Christensen
author_rank: Super Contributor
timestamp: April 14, 2024, 04:30:13 am
content: You could have another stuck button (Shorted/on) which is confusing the key-switch polling. Also, check D15, D17 & D18.If you have a scope, check the outputs on IC22. You should see some short logic low pulses on pins 7,9-12 as it scans the switches. If you see that, then IC22 is probably OK.

author: cincin
author_rank: Regular Contributor
timestamp: April 14, 2024, 05:25:14 am
content: Good point!The other tact switches work fine, and I just tested that they are not shorted on.What I've been calling encoders are actually just mechanical rotary switches, and they all check out too.I checked D15, D17 and D18 and they all test fine.I will put IC22 on the scope in the morning. Maybe between the scope and touching up on basic diode scanning and multiplexer fundamentals I'll figure it out.Will report back.Thanks!

author: cincin
author_rank: Regular Contributor
timestamp: April 15, 2024, 06:31:09 am
content: Well.... turns out I didn't have continuity all the way through after all... I think I got mislead by the fact that the components are not physically connected in the same order as they are in the schematics. That and following the trace back and forth on the double-layer PCB.In any case, there was a small break by an oxidized via. Glad I double checked.It has now been repaired and the synth lives again!A nice reminder that schematics represent logical connections, not physical connections.Thanks for the help!
TACTILE SWITCH - Page 1
Forum section: electronics / beginners

author: Abayomi
author_rank: Contributor
timestamp: September 12, 2016, 11:13:46 am
content: How to use a tactile switch in together with flip flop or latch. That is, if I press the switch the flip flop the output toggles, when i release the switch the output hold its state, when I press the switch the output changes state

author: Blastcap
author_rank: Regular Contributor
timestamp: September 12, 2016, 11:38:58 am
content: You mean like this?

author: bitslice
author_rank: Frequent Contributor
timestamp: September 12, 2016, 12:56:23 pm
content: source:http://phlaphead.blogspot.co.uk/2010/09/push-button-toggle-onoff-circuit.html

author: Brumby
author_rank: Unknown
timestamp: September 12, 2016, 01:13:07 pm
content: Back to basics.....

author: tooki
author_rank: Super Contributor
timestamp: September 13, 2016, 12:43:50 pm
content: Correct me if I'm wrong, but these days, isn't the absolute cheapest way to use an ATtiny MCU or something? As much as I love the idea of discrete components and jellybean logic chips, it seems MCUs do it far cheaper in the end...

author: Ian.M
author_rank: Super Contributor
timestamp: September 13, 2016, 01:11:51 pm
content: That's only true if you have high enough volume, and can write off the one-time costs e.g. Microchip PIC10F200 can be bought from Microchip Direct for as little as $0.34 USD each, preprogrammed with your code, provided you are ordering more than two reels at a time (3000 per reel). If you are only building 10 units, you are probably looking at half a day to write and test the debouncer and program all the chips, which could easily add $20 to the cost of each unit, by the time you've figured in wages and business overheads.

author: chota.sanjiv
author_rank: Contributor
timestamp: September 13, 2016, 02:26:46 pm
content: http://www.mosaic-industries.com/embedded-systems/microcontroller-projects/electronic-circuits/push-button-switch-turn-on/latching-toggle-power-switch
Taiyo direction finder, troubleshooting - Page 1
Forum section: electronics / beginners

author: Hoogin
author_rank: Newbie
timestamp: July 14, 2011, 10:12:26 am
content: Hello, i have a Taiyo direction finder which is malfunctioning. I've narrowed the problem down to the power supply with the help of the schematics found in the instruction manual. I have trouble figuring out which components which are at fault.SymptomsWhen you turn on the unit it takes a little while can be directly or a few minutes the lights and display starts blinking. Your hear beeps in the speaker and bangs. It's unusable.MeasurementsI measured the 5 volt and 9 volt lines with oscilloscope and the 9 volt line is jumping from 9 volts to around 8.8 volts and back, at the same time as it does that the 5 volt does the same but from 5 volts down to 4.5 volts.I've attached the parts of the schematics which involves the power supply.I'm thinking there might be a busted cap somewhere?Since I'm fairly new to electronics any insight or help is really appreciated.

author: ElektroQuark
author_rank: Unknown
timestamp: July 14, 2011, 10:59:32 am
content: A very good and detailed set of images of both sides of the power supply PCB assembly are a must to be able help you.

author: Hoogin
author_rank: Newbie
timestamp: July 14, 2011, 12:17:23 pm
content: These are the best pictures i could take with my camera. Can borrow a better one this weekend.

author: Rufus
author_rank: Super Contributor
timestamp: July 15, 2011, 03:17:34 am
content: Quote from: Hoogin on July 14, 2011, 10:12:26 am'jumping' doesn't tell us anything much, post a trace or photo from the scope?My guess is an intermittent overload on the +5v supply which puts the 5v regulator into current limit and the 9v supply feeding the +5v regulator droops a bit with the overload.

author: Zad
author_rank: Super Contributor
timestamp: July 15, 2011, 03:35:48 am
content: When the fault shows, tap the board with the insulated end of a screwdriver. If the voltage fluctuates then you have a dry joint and need to examine the relevant solder connections with a magnifying glass.If the voltage regulator is getting hot, then suspect an overload or short circuit somewhere.Check all the related electrolytic capacitors for any sign of bulges or deformation of the casing. Electrolytic capacitors are one of the least reliable components, especially cheap ones.

author: Hoogin
author_rank: Newbie
timestamp: July 15, 2011, 04:01:42 pm
content: Quote from: Zad on July 15, 2011, 03:35:48 amI tapped it when it was acting up and it stopped. I tapped it again and i saw on the oscilloscope that the 5v line fluctuated but the 9 volt did not.This afternoon I'm going to be able to take better pictures of the board. I'll look around and see if i can find any odd looking joints or caps on the board.
Take it apart (1935) - Moving light message displays - Page 1
Forum section: electronics / beginners

author: Pat Pending
author_rank: Regular Contributor
timestamp: May 04, 2013, 12:50:47 am
content: An uneventful video until "Take it apart" was spoken.

author: pickle9000
author_rank: Super Contributor
timestamp: May 04, 2013, 01:33:22 am
content: I wonder if rodents where a big problem? Not to be gross but there are many moving parts.

author: SeanB
author_rank: Super Contributor
timestamp: May 04, 2013, 05:58:10 am
content: Not likely, no food left by the workers, who probably had strict lunch rules, and ate at ground level. Anyhow most of that wiring was asbestos insulated as well, not a thing rodents like to eat.

author: free_electron
author_rank: Super Contributor
timestamp: May 04, 2013, 02:33:36 pm
content: An to think that now we need more than a million transistors to do the same. All you need is some paper with holes in it....

author: TerminalJack505
author_rank: Super Contributor
timestamp: May 04, 2013, 02:41:46 pm
content: I got a kick out of the guy smoking a cigarette. While working. From 20 stories up.And I didn't see any safety harnesses on some of those guys.Those were the days.

author: SeanB
author_rank: Super Contributor
timestamp: May 04, 2013, 02:55:55 pm
content: And he rolled it himself, with paper and tobacco from a pouch as well....... Lit with a lighter fuelled with Benzine as well.
Taking a device mobile - Page 1
Forum section: electronics / beginners

author: paul_allsopp
author_rank: Newbie
timestamp: January 19, 2017, 05:39:57 pm
content: Hey AllI have a device that connects to my phone provider, to provide mobile broadband, and would like to look into making it mobile. Right now it uses a power brick (12VDC, 1.5A). I assume that the biggest current draw would be while it's transmitting. How would I hook it up to my scope, to find out what it's power consumption is at it's heaviest, or otherwise if I don't need a scope, just math.What I'd like to do is make the thing battery operated so I can take it out into the wild. My thoughts are that I use a couple of 11V 2200mAh, hobby batteries with some kind of regulator circuit.Is this even possible?Thanks
Taking apart an EICO 460 Oscilloscope - Page 1
Forum section: electronics / beginners

author: PDX460
author_rank: Newbie
timestamp: August 26, 2018, 07:25:54 pm
content: Hi Everyone,This is my first post. I picked up an EICO 460 Oscilloscope a few years back, with the intention of taking it apart one day. When I purchased it, I plugged it in and it seem to work OK, although I have never used an Oscilloscope before.It has been in the garage for about 6 years, and I now want to take it apart. After I removed the housing, I noticed the large CRT and remembered hearing that CRTs can hold a charge for a long time, and can effectively kill you if you are not careful, so I stopped.All I want to do is gut the unit so that I can convert it into something else, and not get electrocuted. I have done extensive searches, but can't seem to find anything specific on taking apart a 460.Any tips/help would be greatly appreciated.Thanks!

author: 6PTsocket
author_rank: Regular Contributor
timestamp: August 27, 2018, 01:57:54 am
content: I think you are confusing CRT TV design with this CRT scope. TV's used the bell of the tube as a big capacitor. The inside of the bell was coated with a conductive coating and accessed by a snap on the glass. The outside of the bell was also coated and formed the other plate. This glass dielectric capacitor was charged to tens of thousands of volts and was the filter for the high voltage power supply. It could hold a charge for months. As a kid I would unsnap the cable going to the inside "plate" of the cap and ground it to the outside "plate" and get a big discharge ZAP before working on TVs. The voltage could actually come back on the plates and the discharge jumper was best left on or at least applied again.The 5UP1 crt in rhe 460 scope has no such built in capacitor. All power connections are to the socket. The high voltage to anode 1 and 2 are around 10OO and 2200 volts and stored on small capacitors in the power supply. I doubt there is a anything left after years in the garage but discharge them to be safe. It is a contiuous sweep scope rather than triggered but it seems like a waste to rip it apart out of curiosity rather than keeping it working There is a market for them.Quote from: PDX460 on August 26, 2018, 07:25:54 pmSent from my SM-G900V using Tapatalk

author: PDX460
author_rank: Newbie
timestamp: August 27, 2018, 05:16:15 am
content: Quote from: 6PTsocket on August 27, 2018, 01:57:54 amThank you so much for the information, I very much appreciate it!

author: Haitarai
author_rank: Newbie
timestamp: August 27, 2018, 07:01:55 am
content: I'm looking for information on the EICO 460 is offline.
Talking to GPIB-Equipment using RS232-Adapter - Page 1
Forum section: electronics / beginners

author: Echo88
author_rank: Frequent Contributor
timestamp: August 22, 2016, 06:18:28 pm
content: Hi,at the moment im trying to control a VXI-Rack via GPIB (Command-Module E1406A) using an old RS232 to GPIB-Adapter (GPIB-232CV-A). Ive already tested the rack via GPIB with a new GPIB-USB-HS-Adapter and it worked flawlessly. But i need to use the old RS232-adapter, as the USB-adapter was just borrowed from work.The problem: all of the VXI-modules in the rack have the GPIB-primary address 30, logical address on the command module 7, with differing secondary addresses (96,99,111,119 for 4 modules) for each module and im not sure how the commands have to look when im using the rs232-adapter and SCPI-standard commands. Can somebody help with those commands and give an example how they have to look in SCPI-format?Its just so frustrating to use that old adapter and dont get a single response from the rack, while the usb-adapter works without flaws. Ive also already successfully tested the rs232-adapter on an old Yokogawa frequency generator (which is simpler, because of only 1 primary address).Thanks,Echo
tantalum cap alternative [SOLVED] - Page 1
Forum section: electronics / beginners

author: shaiss
author_rank: Contributor
timestamp: January 20, 2016, 02:54:39 pm
content: I'm trying to build a derivative of the BlinkStickhttps://www.blinkstick.com/help/build-1-1.In their kit they supply a 104 .1uF Tantalum Capacitor. I don't have any Tantalums in my chest of parts so I'm curious if there's something else like I can use, ie an Electrolytic or Ceramic. Either would be fine and any help's appreciated.The original schematics are @https://www.blinkstick.com/files/schematics/blinkstick/blinkstick-v1.1.pdfif it helps or eaglecad files @https://www.blinkstick.com/files/schematics/blinkstick/blinkstick-v1.1.zip.Thanks again for helping out a noob!

author: Performa01
author_rank: Super Contributor
timestamp: January 20, 2016, 03:30:15 pm
content: Use ceramic caps instead - they are the better alternatives anyway.Tantalum is vastly better at higher frequencies than aluminum electrolytic, hence the latter wouldn't be suitable here.And then for private projects, I generally wouldn't consider any electrolytic - be it aluminum or tantalum - for capacitance values <1µF.

author: shaiss
author_rank: Contributor
timestamp: January 20, 2016, 03:32:06 pm
content: thanks for the quick reply! I presume its a 1 for 1 substitution and I'd use the same 104 ceramic cap?

author: Performa01
author_rank: Super Contributor
timestamp: January 20, 2016, 03:34:07 pm
content: Yes, of course you do!And on top of that you need not worry about polarity!

author: shaiss
author_rank: Contributor
timestamp: January 20, 2016, 03:35:12 pm
content: awesome! thx for the quick reply!
Tantalum cap with no polarity marking - Page 1
Forum section: electronics / beginners

author: Chris_PL
author_rank: Contributor
timestamp: July 25, 2013, 07:24:04 pm
content: Hi everyone!Any idea how to determine polarity on this thru-hole 4.7u/25V tantalum cap? There's absolutely nothing on it except manufacturer's logo, rating numbers i.e. 4.7 / 25 and legs are perfectly equal in length. I know that tantalum caps are often a "trap for young players" because they have markings on (+) instead of ( - ), but I already know this (it took a few blown caps though)

author: free_electron
author_rank: Super Contributor
timestamp: July 25, 2013, 07:38:24 pm
content: positive is side where the logo is printed. logo is asymmetrical from center.but, this could be a better solution: Open window first then take a rubber band and put it around your index and middle finger. Hook the capacitor body over the rubber band so the body points away from you , the rubber band is between the legs and the legs point towards you. Now spread index and middle finger in a v-shape, and using the other hand stretch the rubber band by pulling the capacitor legs towards you holding the hand with the rubber band on it at a steady distance from your body.Aim through window and release the capacitor legs ....problem solved..

author: ConKbot
author_rank: Super Contributor
timestamp: July 25, 2013, 11:10:17 pm
content: You can test by charging the cap In both polarities through a high value resistor. ( couple hundred k ohms) Which ever polarity has a higher voltage on the cap is the correct polarity. The lower voltage means more leakage current in that orientation.

author: c4757p
author_rank: Super Contributor
timestamp: July 25, 2013, 11:19:32 pm
content: Tantalum caps aren't just a trap for young players, they're smelly turds for anyone. Who cares which side is which, chuck it in the bin.(I say, as I'm designing tantalums into something at this very minute.OK, they're notthatbad...)

author: Bored@Work
author_rank: Super Contributor
timestamp: July 26, 2013, 05:22:48 am
content: Solder it into the circuit. Turn the circuit on. If you got the polarity wrong it'll blow up. If you got the polarity right it might blow up, too. In any case, problem solved.
Tantalum capacitor ID - Page 1
Forum section: electronics / beginners

author: pjhenley
author_rank: Contributor
timestamp: October 15, 2019, 04:05:38 pm
content: I'm attaching a photo of what I believe to be a tantalum capacitor with color-code markings. If I am interpreting this correctly, the multiplier dot has ended up on top of the capacitor instead of the side.That would make it brown, green, x grey, blue for 15x.01 uF 20 V= 150nF 20 V, with the blue stripe on the positive side?Is that correct? The reason I'm doubting it is that this cap is larger than the 10 uF tantalums in the same device, which have printed values on them. Also, is that a black band on the bottom near the leads?I would attempt measuring it, but that meter is down at the moment. Any help appreciated.PJ

author: pjhenley
author_rank: Contributor
timestamp: October 15, 2019, 04:15:15 pm
content: Photo:

author: andy3055
author_rank: Super Contributor
timestamp: October 15, 2019, 05:36:44 pm
content: You can try this site:https://www.google.com/search?q=tantalum+capacitor+color+code&tbm=isch&source=iu&ictx=1&fir=BDKfUKWCSsJ1IM%253A%252CE27ecBMF97oooM%252C_&vet=1&usg=AI4_-kTTSdyaZRA3wdZo2Vbp6fLJNo_U8A&sa=X&ved=2ahUKEwjtwNqT5J7lAhURup4KHQPADcUQ9QEwAnoECAQQBg#imgrc=BDKfUKWCSsJ1IM:

author: RES
author_rank: Regular Contributor
timestamp: October 15, 2019, 07:01:21 pm
content: silver - brown, black and green (blue not part of color code?)silver 10%10 + 00000 = 1000000nF = 100uFor10 + 00000 = 1000000pF = 1uF?

author: Gyro
author_rank: Super Contributor
timestamp: October 15, 2019, 07:19:45 pm
content: Quote from: RES on October 15, 2019, 07:01:21 pmI really hate those old blob codes.The 100uF looks plausible but I doubt the 100V combination.The first image in andy3055's link (1uF 16V) seems to imply that green is 16V, which seems more believable.(missed your edit)
TC4053BP possible replacement from reputable vendor - Page 1
Forum section: electronics / beginners

author: belzrebuth
author_rank: Frequent Contributor
timestamp: August 05, 2024, 01:35:24 pm
content: I don't want to order from eBay as the chance of getting fakes is high and I don't want to wait either.I've seen datasheets between the CD4053 which is a candidate as it's also higher voltage and they seem pretty close.I don't know if the TC4053 is actually faster because I've seen that it has a switch on time almost half of that the CD has (380 vs 720nS)Can I replace TC4053 with a CD4053?Application is not a highspeed design; it's a waveform mixer that select VCO outputs on an analog music synthesizer keyboard (Roland Jupiter 6).

author: Kleinstein
author_rank: Super Contributor
timestamp: August 05, 2024, 01:42:48 pm
content: CD4053 and HEF4053 should work. There may be slight difference between manufacturers. If the supply is +-5 V or less one could also use 74HC4053.If money is not not an issue the max4053 should also work.For the speed ratings one has to check the conditions / supply voltage.As this is a pretty low cost part, chances are not that bad to get OK parts even from eBay.

author: Benta
author_rank: Super Contributor
timestamp: August 05, 2024, 01:54:12 pm
content: MC14053BCP from ON Semi.

author: ftg
author_rank: Frequent Contributor
timestamp: August 05, 2024, 02:31:05 pm
content: If you are using TC4053 in a DIP package, then you could fit a socket on one unit and buy a selection of CD4053/HEF4053/MAX4053/MC14053BCP and seeing if there is any difference that can be heard.But if it is just switching some analog signals and it does not have the swap between the inputs every millisecond, I'd suspect any of them would work fine.
TC5816BFT NAND data recovery - Page 1
Forum section: electronics / beginners

author: SCAR17s
author_rank: Newbie
timestamp: December 31, 2020, 04:56:43 pm
content: Hello, I'm trying to repair a scan tool from the mid/late 90's, I have a working, and NON working version of the scan tool on hand. The last person that had the device removed these 2 chips and they were lost. I'd like to copy the data from the 2 good ones I have, onto a new set of them, so I can continue with the repair, anyone have any experience with these older units?Much appreciated!
TCL TV Dual Voltage power supply? - Page 1
Forum section: electronics / beginners

author: smorello
author_rank: Newbie
timestamp: August 26, 2023, 01:11:41 am
content: Hi! I'm new around here and even though electronics was a mandatory class in my technical high school, I have very little confidence in my expertise on the topic. I found this threadhttps://www.eevblog.com/forum/beginners/is-it-possible-to-know-if-this-power-supply-is-universal-by-exmaining-the-pcb/msg3997012/#msg3997012as I was trying to figure out whether my TCL TV is dual voltage (I plan on bringing it to my parents in Europe on my next trip home, since I have no use for it here in the US) and since my TV has a slightly different PCB compared to that of the user in that thread I thought I'd give it a shot.Here's a link to my parthttps://www.shopjimmy.com/tcl-08-l131w44-pw200aa-power-supply-board-led-driver/I have been trying to reverse-engineer the PCB by following the methodology offered by the users in the replies, but to no avail. Is anybody willing to help me figure this out?

author: wraper
author_rank: Unknown
timestamp: August 26, 2023, 01:21:18 am
content: Use of 450V electrolytic capacitors without PFC suggests it should be fine with 230V.

author: u666sa
author_rank: Frequent Contributor
timestamp: August 26, 2023, 01:35:39 pm
content: Quote from: smorello on August 26, 2023, 01:11:41 amYes it is. And no, do not bring it over to Europe from the U.S..Bring money, buy brand new television in Europe. TCL or iFFALCON are the same. Get QLED technology, Q72 for example, 50 inches, or more. 65 inches would be ideal for an average European room. 75 inches is king, but not as big as one might think, and would fit nicely any average sized European bed room or living room.It's a bad idea to bring your television back to Europe. Because you are paying money to bring it, and you are paying customs -- for what essentially is an old television with small screen size (because I don't think it is 50 inches).Bring money with you, they are cheap.

author: smorello
author_rank: Newbie
timestamp: November 13, 2023, 08:19:51 pm
content: Thank you all, a quick update to say that I ended up selling it... to someone who ended up bringing it to Europe anywayApparently it does work there as well.
TCP Data acquisition DMM6500 - Page 1
Forum section: electronics / beginners

author: Voulez
author_rank: Newbie
timestamp: September 03, 2024, 07:50:18 am
content: Good afternoon,I found python script in Data Logging of Power Profiles from Wireless IoT and Other Low-Power Devices to stream digitized current readings over a LAN connection to an external computer. However when I run it I get values that don't match the values I get on the front panel of device. I have tried to decode data that I get but it won't work. Is there something that needs to be modified in these scripts? I provided scripts in text format.Thanks in advanceBest regards,Vukasin Pavkovic

author: ArdWar
author_rank: Frequent Contributor
timestamp: September 03, 2024, 10:23:18 am
content: Your python script didn't decode the data properly. Please read howformat.REAL32works.Here an example how to decode the datastream. Not the prettiest nor most efficient but at least it works (for me)Code:def write_block(ofile, floats):r = 4 #REAL32data = [floats[x:x+r] for x in range(2, len(floats)-1, r)]for f in data:ofile.write("{0:.4e}\n".format(struct.unpack('f', f)))

author: Voulez
author_rank: Newbie
timestamp: September 03, 2024, 11:22:19 am
content: Well thank you so much!I am not very good with python and data formats
TCS4615 Step-down Regulators - Page 1
Forum section: electronics / beginners

author: rishivg
author_rank: Newbie
timestamp: February 07, 2024, 07:57:17 pm
content: Hi, I'm having a really hard time finding the datasheet or schematic implementations of the TCS4615 step-down regulator (Chinese component). Just searching for it on the internet produces no meaningful results. Does anyone have resources to help me out with this? Thank you in advance!

author: soldar
author_rank: Super Contributor
timestamp: February 07, 2024, 08:11:06 pm
content: try mouserhttps://eu.mouser.com/c/semiconductors/power-management-ics/voltage-regulators-voltage-controllers/?q=4615
TCXO Fanout - Page 1
Forum section: electronics / beginners

author: veeti
author_rank: Contributor
timestamp: July 24, 2020, 05:29:22 pm
content: Hello"All" TCXO chips seem to have 0.8 vpp clipped sine. I wan't to fan out it to 4. All buffers what i find have logic 1 needs over 0.8V. i.e CDC3RL02 Low Phase-Noise Two-Channel Clock Fan-Out Buffer.https://www.ti.com/lit/ds/symlink/cdc3rl02.pdf?ts=1595611466986&ref_url=https%253A%252F%252Fwww.google.com%252FI found many schematics where you use logic inverter to buffer it up.But there must be just buffer/fanout ic wich works with TCXO without any extra amplifiers? or is there?EDIT: i want to drive pll, fpga and ADC - 3 volts to all.This is the best what i have found, but there is still that inverter.

author: veeti
author_rank: Contributor
timestamp: July 24, 2020, 06:52:41 pm
content: And there we have it - took only 6h 🤪https://www.idt.com/us/en/products/clocks-timing/clock-distribution/clock-buffers-drivers/5pb1203-18-v-13-tcxo-lvcmos-high-performance-clock-buffer

author: MasterT
author_rank: Frequent Contributor
timestamp: July 24, 2020, 09:06:38 pm
content: Not all, there are series :"733 (Clipped Sinewave TCVCXO)I734 (HCMOS TCVCXO)"https://www.arrow.com/en/products/i734-2p3-10.000mhz/mmd-components
tda 2050 bridge - Page 1
Forum section: electronics / beginners

author: rahulrahullll
author_rank: Contributor
timestamp: January 10, 2018, 11:04:35 am
content: i have 2 separate tda 2050 mono boards working separately fine—-but if i bridge them—-huge distortion–slight song coming out——————-c1 cap wrong given—-i have reversed polarity—-i have +/- 22 v dc-------unregulated with transformer--16-0-16 v ac---circuit tested-----https://youtu.be/i_HmCorNBi4-----------https://3.bp.blogspot.com/-dM-f-4sFugI/WdNiPMwUSmI/AAAAAAAAAPQ/ffpf4BxmJEcs33dHMHcVuUtyurY_DVKJACLcBGAs/s1600/BTL.JPG———-is there anything wrong ?—-thank you

author: Zero999
author_rank: Super Contributor
timestamp: January 10, 2018, 07:03:10 pm
content: Actually, C1, C2 and C4 should be non-polarised, as there's no DC bias across them.Does it produce any sound when nothing is connected to the input? Perhaps it's oscillating?Have you connected an 8R resistor, in place of the speaker and looked at the output on an oscilloscope, with the input connected to a signal generator.

author: Audioguru
author_rank: Super Contributor
timestamp: January 10, 2018, 10:24:05 pm
content: I heard the sound break up when you turned the potentiometers. Breadboards are known to produce intermittent connections and their rows of contacts and messy wires all over the place have capacitance between them causing oscillation. The rows of contacts and messy wires all over the place also pickup mains hum and all kinds of interference.There is no way a solderless breadboard can pass the 4A to 5A from your circuit.But you never said the speaker impedance. 4 ohms is too low, 8 ohms peak current will be about 5A which is the maximum allowed current from a TDA2050.I saw the power supply in the bucket blinking its blue LED on the loudest parts so it is having trouble producing 5A. I did not see a speaker in a proper enclosure.Get rid of the solderless breadboard and solder everything together compactly. Use a power supply that is not overloaded. You played music (??) that I have never heard before since I have never been to your side of the world.
TDA1072 oscillator doesn't oscillate - Page 1
Forum section: electronics / beginners

author: Simon123
author_rank: Regular Contributor
timestamp: March 27, 2020, 04:18:22 pm
content: Hy.I built oscillator using this circuithttps://www.qsl.net/va3iul/Homebrew_RF_Circuit_Design_Ideas/600kHz-60MHz_Signal_Gen_TDA1072_DD0RQ.gifFor coil i used AM loopstick antenna and capacitor air variable.The thing doesn't want to oscillate tho. (I checked using dmm frequency counter also on radio i cant hear any transmission from this circuit.)What could be the cause?

author: Simon123
author_rank: Regular Contributor
timestamp: March 27, 2020, 04:23:47 pm
content: Also, i bought TDA1072 from ebay.

author: Zero999
author_rank: Super Contributor
timestamp: March 28, 2020, 10:03:10 pm
content: I think you've answered your own question: you probably have a fake part.Unfortunately the TDA1072 isn't made any more, so it's quite likely and you find for sale will be fake, unless you're lucky and get used or new old stock parts.
tda2030 leads - Page 1
Forum section: electronics / beginners

author: LaserTazerPhaser
author_rank: Regular Contributor
timestamp: May 29, 2019, 01:03:39 am
content: Whats the purpose for a tda2030 leads being very irregularly spread out? Would it be fine to flatten them inline such as a lm1875 and employ them for audio or will it cause noise on the output?

author: oPossum
author_rank: Super Contributor
timestamp: May 29, 2019, 01:32:35 am
content: They are staggered to allow more room for PCB traces. Flattening them won't be a problem.

author: CJay
author_rank: Super Contributor
timestamp: May 29, 2019, 11:00:15 am
content: You used to be able to buy the TDA2030 in a variety of lead configurations and I'm pretty sure one of the was with 'flat' leads.Similarly, you can buy the LM1875 with staggered leads.
TDA2030A amp, Single supply vs+ +/- dual rail - Page 1
Forum section: electronics / beginners

author: rwgast_lowlevellogicdesin
author_rank: Frequent Contributor
timestamp: April 10, 2015, 04:30:04 pm
content: I have a small 25 watt 4ohm sub laying around and a I found a few TDA2030A amp chips I was thinking about using to power it.After reading the data sheethttp://www.parts-express.com/pedocs/specs/ST-Electronics-TDA2030A-Specifications.pdfIt shows examples of using a split supply and a single positive supply. May I ask what the difference is, what impact would using a single ended positive DC supply have on audio quality over using a +/- split rail?

author: mariush
author_rank: Super Contributor
timestamp: April 10, 2015, 04:49:14 pm
content: Split power supply is a bit better because it saves you the trouble of having to use a large capacitor on the speaker output.Note that 2030A needs quite high voltage to output decent amount of power, if you want 18-20w - real ones - you need to feed this amplifier chip with about +/-20v or around 36-40v (for single psu). With low voltages like 12-24v, the chip sucks.The chip is also fairly inefficient at around 65-70% so be prepared to use a large heatsink.My advice would be to just go buy a TDA2050 (datasheet here:http://diyaudioprojects.com/Chip/DIY-TDA2050-Hi-Fi-Chip-Amplifier/TDA2050-Datasheet.pdf) if you want to keep it in the same family, or just go for better class D amplifier chips as these don't require heatsinks to work and they'd also work at high power outputs with lower voltages like 12v or 24v

author: rwgast_lowlevellogicdesin
author_rank: Frequent Contributor
timestamp: April 11, 2015, 12:45:59 am
content: I also have a STK4026 II power amp chiphttp://www.datasheets.pl/integrated_circuits/S/STK/STK4026.pdfIs this a better choice? I thought it was a bit overkill, its huge.....Im not opposed to ordering a better chip id just like to use something I have on hand. These chips actually came out of a very expensive onkyo receiver I ripped apart and got from a swap meet.Im only driving a 25 what 4ohm sub, maybe a discrete design with some 2n3055's would be the way to go, but that seems more complicated and I really just want to get the amp part done!
TDA2050 Hi-Fi Chip Amplifier Resistor Pick Help - Page 1
Forum section: electronics / beginners

author: ecks
author_rank: Newbie
timestamp: March 24, 2015, 03:15:59 pm
content: Hello,I have a bit of experience in electronics, but it mostly through coursework and I would like to build something practical. I had some TA2050s lying around so a friend of mine suggested I build the amplifier shown inhttp://diyaudioprojects.com/Chip/DIY-TDA2050-Hi-Fi-Chip-Amplifier/. I was looking at resistors R1, R2 and R3 and they don't look like the regular resistors we have lying around in the lab, ie we have stuff that looks like R4. I know that resistors are rated for different watts, but unfortunately from the description it doesnt say what rating I should look for. Would it be okay to make due with regular resistors that look like R4, or would I need to look for the bulky ones?

author: TimFox
author_rank: Super Contributor
timestamp: March 24, 2015, 03:28:38 pm
content: I would use a 2.2 ohm, 2 or 3 Watt "flame-proof" cermet resistor (metal oxide) for R4.For the other resistors, use 1/4 or 1/2 watt metal film resistors (1% would be a good idea, but not absolutely necessary).As an old person, I like military-style RN60 resistors for the metal film units.

author: flynwill
author_rank: Regular Contributor
timestamp: March 24, 2015, 03:44:31 pm
content: You can use ordinary 1/4 watt carbon film resistors for all 4 parts. Metal film and higher precision are nice (and will work if you have them laying around) but are hardly necessary in this application. I note that the schematic calls for R4 to be a 2W part, but I can't see any reason why, with that 0.47 uF cap in series it isn't going to see very much current unless you feed the amp full power 20kHz. Possible, but not very likely in normal usage (although I suppose if you want to design for the worst case...). I note that in the picture R4 appears to be a normal 1/4 watt part.

author: Zero999
author_rank: Super Contributor
timestamp: March 24, 2015, 03:48:20 pm
content: Carbon film can be used but it's more noisy than metal film and resistors are cheap so you may as well pay a tiny bit more and use metal film.Two bridge rectifiers seems unnecessary. Centre tap the transformer and use one.The 2k2 bleeder resistor seems a bit low. It's not even required for safety as the voltage is too low to be a hazard, especially when the power is disconnected. The TDA2050V has a quiescent current drain of 55mA at +/-22V, dropping to 30mA at +/-4.5V which is greater than the current through the bleeder.The TDA2050V is obsolete so beware you may have difficulty sourcing spares and you certainly shouldn't market this.The absolute maximum voltage rating is 50V so running it off a 18-0-18V transformer is cutting it a bit close, given the voltage will be higher when unloaded and if the mains voltage is on the high end.Read the datasheet before building this:http://www.st.com/web/en/resource/technical/document/datasheet/CD00000131.pdf
TDA7000 - Page 1
Forum section: electronics / beginners

author: Simon123
author_rank: Regular Contributor
timestamp: October 22, 2013, 04:05:32 pm
content: Hello!I have built TDA7000 fm receiver, but it drifts, sometimes it seems that it locks little bit, but then it drifts away.I have used this schematic, just with pin 1also connected threw 2.2k to +5.Instead of Bf94 i used bf199 and BB329.http://www.elektronicaforum.nl/files/tda7000rx.jpgWhat part of the circuit should i be testing?Thanks!

author: Paul Price
author_rank: Super Contributor
timestamp: October 23, 2013, 12:25:09 pm
content: Your schematic is in error regarding freq. control and also the regulator circuit pins are vague.Download the datasheet for the TDA7000.
TDA7294 and the single supply - Page 1
Forum section: electronics / beginners

author: Katanara
author_rank: Contributor
timestamp: February 16, 2023, 04:21:43 pm
content: Greetings! I have a question about the power source for TDA7294. It implies a split supply. I have previously used +/-24V. Now I need to use the 0 and 48V power rails. 0 to Vs-, 48 to Vs+, and the mid 24V to pins that are supposed to be connected to GND.Will it work? There are some worries about this case and I think I could not clearly understand the datasheet.

author: strawberry
author_rank: Super Contributor
timestamp: February 16, 2023, 04:51:43 pm
content: resistor divider and some transistor bufferinput and output DC blocking capacitorsfor mute/stby some transistor for level shiftingeasy

author: Katanara
author_rank: Contributor
timestamp: February 16, 2023, 04:59:23 pm
content: Not so easy for a newbieBlocking capacitors are of course needed.
TDA7297 amplifier board questions - Page 1
Forum section: electronics / beginners

author: Lucky-Luka
author_rank: Unknown
timestamp: May 13, 2022, 03:33:37 pm
content: Hi allI would like to design this simple PCBhttps://xtronic.org/circuit/amplifier/circuit-stereo-power-audio-amplifier-using-tda7297-2-x-15-watts-mute-and-stand-by-optional-easy-to-assemble/1)What are the power rating of the resistors and of the dual potentiometer?2)Do you see anything wrong in the schematic?Thanks

author: m k
author_rank: Super Contributor
timestamp: May 18, 2022, 03:03:10 pm
content: 1) scroll down a bit, power ratings are there.2) there are positive comments.

author: tepalia02
author_rank: Regular Contributor
timestamp: May 19, 2022, 07:00:13 am
content: Ratings are given in the article. See the 'BOM for assembling the circuit with TDA7297' part.I don't see any problem with the design.

author: MathWizard
author_rank: Super Contributor
timestamp: May 19, 2022, 03:38:20 pm
content: You could add a backwards diode on the power input, for in case if u ever connect the power wrong, or from the wrong polarity jack or whatever.Something like a 1N400x would be fine, they all cost pennies. The idea being to allow a current in that diode, and drop the voltage across it, and not have enough voltage across any chips or caps in parallel with the PSU, that the reverse polarity blows them up...and hope it's not an ideal voltage source.
TDA7418 Audio Processor - Page 1
Forum section: electronics / beginners

author: Sai Shoby
author_rank: Newbie
timestamp: October 15, 2020, 08:44:46 am
content: Hi,I am having TDA7418 Audio Processor connected with PIC18F(scl and sda) . I am very new to this. Can anyone help me to tell how to configure and test TDA7418. ?anyone have source code for TDA7418.? Please share more details about itthank you