hybridfree/eevblog-posts huggingface dataset:
CNC 2417 connections configuration driver firmware - Page 1
Forum section: electronics / beginners

author: boxcorner
author_rank: Newbie
timestamp: June 17, 2018, 12:56:37 pm
content: Hello EEVI'm new here so I hope this is the right section to post this and that I'm not treading on anyone's toes here.I have ordered a CNC 2417 from Aliexpress in China. The software they provide comprises a document file, instructions for mechanical assembly of the machine and a large ZIP file which I have been unable to download because the connection it keeps timing out.I had hoped there would be a list of steps required to get the machine up and running, or better still a flow chart!My understanding is the CNC 2417 has an Arduino UNO and motor shield. I believe the Arduino needs to have Gbrl firmware installed and presume this can be done using the Arduino IDE. The Arduino will be connected to a computer via USB. I believe driver software needs to be installed on the computer before it is connected to the Arduino. The computer would need to have an app installed to generate G-code, plus an app to drip-feed the G-code to the Arduino, as it doesn't have a large memory capacity. That's my understanding thus far. Is that correct?So the steps would be: (1) assemble the machine (2) install motor drivers (3) install an app on the computer to generate G-code eg InkScape (4) install an app on the computer to drip-feed the G-code to the Arduino.Is that correct?Whilst there are many videos showing people lovingly opening the box and assembling the kit of parts, playing with Allen keys to build the machine, there seems to be very little information about the electrical connections and no step-by-step sequence to get the machine up and running with drivers and firmware, that I have been able to find.While looking around for alternative software, I stumbled across Banggood's web page offering what appears to be the same machine. There's a link which leads to a Google Drive page where files can be downloaded individually, instead of a huge ZIP file. Much more user-friendly.The driver says it's for DOS/Windows. Does anyone know where I might find a driver for Linux? I still have an old computer that is configured to dual-boot Linux/Win7, so that is not a major problem, but I would prefer to use Linux.So to recap. Where might I find electrical connection info for this machine? Are the steps that I enumerated above correct? Where might I find drivers for Linux?Any help would be much appreciated. Thanks in advance.

author: innkeeper
author_rank: Unknown
timestamp: June 23, 2018, 03:18:40 am
content: Hi,I've done a bit of custom cnc building, and 3d printers, which, is somewhat similar in this regard.if you are getting a kit blind, without knowing what firmware to run, or even if the drivers will run the steppers, there are a lot of pitfalls there. I would hook up with one of the CNC forums like CNC Zone.I'm not one to point people to another forum, but, in this case, id seeks out a forum that specializes in CNC as it really is that deep a topic.Yes, there are drivers for Unix for CNC but that a pretty broad topic.
CNC machine help - Page 1
Forum section: electronics / beginners

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 26, 2016, 03:45:56 pm
content: So recently i gotten a CNC machine. (which i am working on for a customer.) But i am having problems working it in the software. This is what i see when i go into the diagnostics area on the program. i do tests on it and it is not running the stepper motors. there IS power going to them however, but the software is not making them actually run. Much help is appreciated. Thanks.P.S. It also comes with routing head and also a heating head to make molds.Software used: UCCNCCNC Machine: GenericController: UC100 CNC Motion Controller.

author: danadak
author_rank: Super Contributor
timestamp: April 26, 2016, 04:37:14 pm
content: Could be a number of things -1) Limit switches wired up correctly to controller ?2) Motor Driver enabled ?3) You can see with scope motor driver is issuing PWM signals ?4) Software is not in simulation mode ?Regards, Dana.

author: rstofer
author_rank: Super Contributor
timestamp: April 26, 2016, 04:46:24 pm
content: I would be wondering what 'Enable X', 'Enable Y', 'Enable Z' was all about. They clearly aren't enabled. See page 15 of 67 in the User Manual.My experience is with Mach 3 coupled to a SmoothStepper board that actually sends the signals to the stepper drivers. Works well!

author: danadak
author_rank: Super Contributor
timestamp: April 26, 2016, 07:08:17 pm
content: I cannot seem to find the manual you are referring to, can you post it.Regards, Dana.

author: rstofer
author_rank: Super Contributor
timestamp: April 26, 2016, 07:33:01 pm
content: Quote from: danadak on April 26, 2016, 07:08:17 pmhttp://www.cncdrive.com/UCCNC/UCCNC_usersmanual.pdf

author: Karlo_Moharic
author_rank: Regular Contributor
timestamp: April 26, 2016, 07:33:59 pm
content: Here the official software publisher sitehttp://cncdrive.com/downloads.html, maybe you can find something useful

author: Nickk2057
author_rank: Regular Contributor
timestamp: April 26, 2016, 11:49:18 pm
content: I found out the problem. found out it is something to do with the profiles that they have not mentioned in the instructionsi swear..... now i have to copy the profiles and macros to go on the persons machine... not to mention is that he is not good with computers, but he knows of CNC stuff....someone get me a beer.... :smh:
cnc problems  - Page 1
Forum section: electronics / beginners

author: kosacid
author_rank: Contributor
timestamp: October 01, 2017, 01:01:03 pm
content: i have a few problems with it, the motor is a M42SP-6TG 10ohm im running them of a 1A 12v as far as i know that is fine but im not sure, the H-bridge im using is a L293D as you can see from the heat sinks they are getting hot, i want to know if that setup is fine ?

author: janoc
author_rank: Super Contributor
timestamp: October 01, 2017, 02:32:36 pm
content: Quote from: kosacid on October 01, 2017, 01:01:03 pmThat'snotfine.Look in the datasheet for L293D:Quote(emphasis mine)It has 1.2A peak current capability, but you are using 1A full time, not peak. So no wonder it is overheating. You need a beefier driver than this. I am surprised that it didn't fry yet.Even if it was L293 (the non-D version) which can handle 1A, that is a very poor design, leaving no safety margins at all. You should never use a part up to its maximum ratings - all it will take for it to blow up is a current spike or a temperature change.

author: kosacid
author_rank: Contributor
timestamp: October 01, 2017, 03:35:48 pm
content: so what is the minimum for them motors i cant find no data on them

author: janoc
author_rank: Super Contributor
timestamp: October 01, 2017, 03:43:55 pm
content: Quote from: kosacid on October 01, 2017, 03:35:48 pmWell, you have measured that the motors take 1A at 12V, no? Or how did you determine that? Or what did you mean by "im running them of a 1A 12v "?If its coils have 10\$\Omega\$ resistance as you have mentioned, then at 12V you end up drawing 1.2A when the motor is standing still.It is a Mitsumi motor, likely a custom variant made for some printer or copy machine. The closest part seems to be their M42sp-6k:http://www.mitsumi.co.jp/latest/Catalog/compo/motor/m42sp6k_e.htmlThere you can see that it is both rated for 21-26V operation and only 550mA peak current, with 8\$\Omega\$ winding resistance. And it also says that the drive method is "constant current". So you need a driver that can do this.The L293D will not limit the current in any way and you end up either destroying the driver or the motor (or both). With L293D you could probably drive the motors from 5V max - that would give you 5V/8\$\Omega\$=0.625A current, but likely less due to the losses in the L293D itself. However that will cost you in the torque of the motor and it will still be running hot, potentially burning itself out over time.There is a reason why chips like the Allegro A4983/A4988 stepper drivers (used in the popular Stepstick modules) have an adjustable current limit!
CNC touch probe problems - Page 1
Forum section: electronics / beginners

author: Smokie555
author_rank: Newbie
timestamp: January 26, 2023, 11:22:50 am
content: Hi, I hope someone can help me,.. I was trying to setup a cheap touch probe with my 6040/Gecko 540 CNC.I have a height touch plate connected and working great through a 2.1mm connector jack on the front of my control box so I wanted to use the same plug in connection to work with the touch probe.Problem is the touch plate simply grounds the centre input pin when the cutter contacts an earthed metal surface, were as the touch probes output wire switches its high 5v signal down to 0v when it touches something.I thought I had it sorted by building a circuit using a 4011 NAND gate to invert this action (low to high) and then switch a mosfet module like a fast relay to act like the touch plate by simply grounding the Gecko’s input pin across the 0V in and -V out on the mosfet module.Worked great on the bench with a meter set to buzzer but unfortunately when I tried it on the machine the Gecko pin stays in the earthed state (mosfet relay connected) regardless of the touch probes state (high or low). Maybe a mosfet leaks a little? But I’m no expert on the electronics.Can anyone suggest what's wrong or think of a better solution. Cheers Ross

author: ataradov
author_rank: Super Contributor
timestamp: January 26, 2023, 06:27:04 pm
content: Having schematics of the connections might help.If the height probe simply grounds the pin, there must be a similar pull-up on the Gecko side. And as long as they are both pulled up to the same voltage there should be no issues. Either your height probe or touch probe would ground and trigger the input.

author: bidrohini
author_rank: Regular Contributor
timestamp: January 27, 2023, 07:53:20 am
content: It appears that there may be an issue with the MOSFET not properly switching to ground the input pin.One potential solution would be to use a different type of switch, such as a transistor or a relay, instead of the MOSFET. Additionally, it may be helpful to check the circuit for any potential issues, such as incorrect wiring or a damaged component.Another option to consider is using an optocoupler to isolate the touch probe circuit from the gecko, this will prevent any leakage current from affecting the gecko and also will provide a much cleaner signal to the gecko.It would be best to consult with an electronics expert or someone familiar with CNC controls to ensure that your circuit is properly designed and functioning.

author: Smokie555
author_rank: Newbie
timestamp: January 29, 2023, 09:55:58 pm
content: Thanks for the reply, yes I was using USB 5v to the probe were as the G540 pin is 12v so maybe thats my problem, we give it another go and many thanks

author: Smokie555
author_rank: Newbie
timestamp: January 29, 2023, 09:59:52 pm
content: Great suggestions, many thanks. I was trying to use the mosfet like a relay as I think a standard relay would be a bit slow to switch but I maybe didn't really understand how they work. Will try again with a transistor, Many thanks for your help
Coated wire insulation, measured 5-10MOhm ? - Page 1
Forum section: electronics / beginners

author: lordvader88
author_rank: Frequent Contributor
timestamp: March 07, 2017, 05:17:00 am
content: I have a roll of 24g wire and checked to see if it was coated/insulated as hoped, and it measured around 4,5 or 10 MegaOhms or something on that order, just with the probes right next to each other. And thats on a brand new quality DMMI wanted to use it for making inductors/RF coils/etc. Is that usable for that if its wound touching itself ? Whats the typical resistance of coated wire ?

author: singapol
author_rank: Frequent Contributor
timestamp: March 07, 2017, 06:10:04 am
content: Are you sure because it will normally be out of range. Official specs. for open circuit is in Gohm range..being at least 1Gohm?Anyway just wind yourself an inductor and measure it,if it is spot on then you have something.
Coax cable from satellite dish to HD reciever quality test - Page 1
Forum section: electronics / beginners

author: JustAnotherGuy999
author_rank: Contributor
timestamp: February 27, 2016, 10:24:56 pm
content: Is there a test that we can do with a multimeter (or probably a scope) to juge the quality of a coaxial cable?

author: KD0CAC John
author_rank: Frequent Contributor
timestamp: February 27, 2016, 10:37:17 pm
content: I use a TDR Time Domain Reflectometer Tektronix 1503C , to work on ham radio feed lines , probably would be more than you would want to buy to do the job , I got mine off ebay for about $200 , the average price is closer to $800 .A multimeter would only give you open / short , using other equipment for measuring impedance would be closer .Then depending on what coax 50 ohm radio gear , 75 ohm for video gear .A TDR is going to give you the beat picture from end to end , a scope not as much detail , but here's Allen's video of using a scope ,

author: uncle_bob
author_rank: Unknown
timestamp: February 28, 2016, 12:59:04 am
content: Quote from: JustAnotherGuy999 on February 27, 2016, 10:24:56 pmHiMultimeter:Pull the gear off the far end. Set the multimeter to the highest resistance range (or to conductivity). The cable should read as open. Then short the cable at the far end. The multimeter should read close to (but not equal to) zero ohms.Bob
cockcroft walton generator - Page 1
Forum section: electronics / beginners

author: Adhith
author_rank: Frequent Contributor
timestamp: December 19, 2015, 03:11:24 pm
content: hello everyonecan i generate a high voltage(around 5kv) using 9v battery. iam planning to use 555 timer to get a pulsating voltage from battery which will be the input of a step up transformer & then to the input of cockcroft walton generator. if this is possible, what will be the specification of the components & no. of stages in walton generator??

author: Paul Price
author_rank: Super Contributor
timestamp: December 19, 2015, 05:21:48 pm
content: http://4.bp.blogspot.com/-JzIgyqLLWoM/Ufs_XEJuPwI/AAAAAAAAE7I/vOXmdYrcQfY/s1600/stun+gun+circuit.png
CoCo 2 5 pin  din connectors - Page 1
Forum section: electronics / beginners

author: peterthenovice
author_rank: Regular Contributor
timestamp: September 16, 2017, 03:08:19 am
content: i am trying to find a male din connector that with fit the CoCo joystick port for an atari - CoCo joystick adapter. this pdf says you can you a six pin connector and remove the sixth pin? I have been scouring ebay and mouser for the eight part. is there a pdf with a list of din connector types? where can i find this part. thanks for any help. CoCo is short for trs-80 color computer.http://sparksandflames.com/files/atari%20joystick.pdfhttp://www.colorcomputerarchive.com/coco/Documents/Manuals/Hardware/Color%20Computer%202%20NTSC%20Service%20Manual%20(26-3134%20&%2026-3136)%20(Tandy).pdf

author: Tomorokoshi
author_rank: Super Contributor
timestamp: September 16, 2017, 04:41:48 am
content: Is this what you are looking for:https://www.digikey.com/products/en/connectors-interconnects/circular-connectors/436?k=din&k=&pkeyword=din&pv518=15&FV=1600007%2C35c0065%2Cffe001b4%2C11400b9&mnonly=0&ColumnSort=0&page=1&quantity=0&ptm=0&fid=0&pageSize=25https://www.digikey.com/product-detail/en/cui-inc/SD-60/CP-1060-ND/96999

author: drussell
author_rank: Super Contributor
timestamp: September 18, 2017, 12:57:56 am
content: It should be keyed the same as the original PC/XT/AT (pre - PS/2 style) keyboard connector.Just snarf one off an old keyboard....

author: drussell
author_rank: Super Contributor
timestamp: September 18, 2017, 04:54:54 pm
content: Hmmm...After reading the .PDF, I take that back... if they used some whacky non-standard 5-pin DIN then I guess you really do need the less-common 270-degree rather than 180 or 240, or the 6-pin and modify it....
Cocroft Walton voltage multiplier problems - Page 1
Forum section: electronics / beginners

author: cobalt
author_rank: Newbie
timestamp: August 11, 2013, 07:19:11 pm
content: I built a small cockroft walton voltage multiplier with 4 stages to quadruple the 120V mains. When I measure from the end of the multiplier to neutral with a multimeter set to DC volts, I'm only getting around 132V. Honestly I'm stumped. If it helps, the components I'm using is vishay WKO series 2.2nF ceramic caps, and vishay P600M 1000V 6.0A diodes. Any help or suggestions would be great.

author: SeanB
author_rank: Super Contributor
timestamp: August 11, 2013, 07:39:39 pm
content: Larger value caps like 100n will be better.

author: mrtarslan
author_rank: Newbie
timestamp: November 10, 2013, 08:55:23 am
content: Good days,I have 1000V 6A diodes and 470uF 450V Capacitors and i dont know how many this electronic parts i will connect and how does it calculate to get 2000Volt DC, can you help, how do i connect and calculate? i am using 12volt battery and 500Watts 12Volt DC to 240Volt AC inverter.Thank you.

author: Psi
author_rank: Super Contributor
timestamp: November 10, 2013, 08:59:43 am
content: Quote from: cobalt on August 11, 2013, 07:19:11 pmDid you have any load on it that may have pulled down the voltage?If not it sounds like there is a wiring error.Remember the cap has to store the voltage over the 50hz cycle. 2nF is pretty tiny.

author: Zero999
author_rank: Super Contributor
timestamp: November 10, 2013, 05:51:43 pm
content: Quote from: mrtarslan on November 10, 2013, 08:55:23 amThe peak voltage of 240VAC is 339V so you need six stages for 2000V.

author: mrtarslan
author_rank: Newbie
timestamp: November 12, 2013, 06:19:24 pm
content: Thank you
code smd EEPROM - Page 1
Forum section: electronics / beginners

author: salviador
author_rank: Regular Contributor
timestamp: November 28, 2020, 11:33:46 am
content: does anyone know this code? what kind of eeprom is it?

author: retiredfeline
author_rank: Frequent Contributor
timestamp: November 28, 2020, 11:52:00 am
content: It appears to be an AT24C64D. See page 24 of the datasheethttp://ww1.microchip.com/downloads/en/DeviceDoc/AT24C64D-I2C-Compatible-2-Wire-Serial-EEPROM-64-Kbit_DS20005937a.pdf

author: salviador
author_rank: Regular Contributor
timestamp: November 29, 2020, 10:29:32 am
content: Hi ,Thank you very much for the information, this eepromthis eeprom is in the u1733c tool , I have the tool blocked due to an update problem, I want to dump it to see if it can be unlocked
Coding of a PIC16F690 - Page 1
Forum section: electronics / beginners

author: Stayne
author_rank: Newbie
timestamp: October 01, 2015, 04:34:31 am
content: I need help for interfacing a PIC16F690 with HC-SR04.Please suggest a moisture sensor that can be interfaced with PIC16F690.Thank you

author: kaadam
author_rank: Contributor
timestamp: October 01, 2015, 06:10:55 am
content: Hello!What is the question about HC-SR04. All you need is using a capture input to measure the impulse length on the echo pin, and generating a trigger pulse with a normal GPIO.For moisiture sensing, i found this:https://www.sparkfun.com/products/13322In this case, you need to hook up the SIG output to an AD input, and read the analog value. If you bulid a prototype only, you can share the power supply between this modul and your µC, and you don't need any level transition. Not the most elegant way, but it's good for getting know the sensor.Good luck!

author: ElectricGuy
author_rank: Regular Contributor
timestamp: October 01, 2015, 03:36:57 pm
content: Quote from: Stayne on October 01, 2015, 04:34:31 amWhat compiler are you using? I've code writed in MicroBasic and MicroC for a 12f1240.Like Kaadam said, its very easy!
Coffee machine waste basket sensor - Page 1
Forum section: electronics / beginners

author: bitwelder
author_rank: Super Contributor
timestamp: July 09, 2016, 08:37:59 am
content: I have a fully automatic coffee machine, one of the those where you supply coffee beans and water, and it makes an espresso at the press of a button.Generally after about 3 coffee 'pucks' it turns on the 'waste-basket full' alert LED.I was wondering, what technology could have they used to detect the condition?The basket is a front-sliding coffee-brown plastic tray, and it doesn't seem to have a load cell to weight it.Or does it just count the pucks dropped after last tray opening?(never tried to open and close without emptying it)

author: Rerouter
author_rank: Super Contributor
timestamp: July 09, 2016, 10:29:51 am
content: to cut costs i would have to say counting, the only other way may be an IR photo detector inside the cavity somewhere, so as an object is close enough it illuminates the light,

author: Ian.M
author_rank: Super Contributor
timestamp: July 09, 2016, 12:56:22 pm
content: Quote from: bitwelder on July 09, 2016, 08:37:59 amYou say 'about'. Does it actually vary or are you simply qualifying the number due to your own uncertain memory?Assuming it does different styles of coffee, I would expect it to meter the beans in some way. It therefore will have a reasonable estimate of the volume of spent grounds per cup.As long as the consequences of a waste bin overflow are not catastrophic, a simple accounting strategy will be a lot cheaper than sensors. Some printer manufacturers use the same strategy and the consequences of a waste ink/toner overflow are far far more unpleasant than some spilt coffee grounds!

author: bitwelder
author_rank: Super Contributor
timestamp: July 09, 2016, 02:56:49 pm
content: Quote from: Ian.M on July 09, 2016, 12:56:22 pmDue to my own random access memory. Lately I always see 3 coffee pucks but I think to remember I've seen 4 at least once.QuoteIndeed, it must be doing some measuring based on the used coffee. I now tried to fill the waste bin with a small bag of dried beans and a box of tea bags and in neither case the machine detected the 'bin full' status (although the volume occupied was even twice of that used by 3 coffee pucks).Thanks!
coil value - Page 1
Forum section: electronics / beginners

author: yalect
author_rank: Regular Contributor
timestamp: March 04, 2015, 03:01:56 pm
content: Hello,I would like to ask you can I calculate the inductance of small coil from its form directly, with a good result and how?Thank you

author: deephaven
author_rank: Frequent Contributor
timestamp: March 04, 2015, 03:04:53 pm
content: Quote from: yalect on March 04, 2015, 03:01:56 pmhttp://www.daycounter.com/Calculators/Air-Core-Inductor-Calculator.phtml

author: T3sl4co1l
author_rank: Super Contributor
timestamp: March 05, 2015, 12:48:06 am
content: Much improved,http://hamwaves.com/antennas/inductance.htmlTim
Coil Whine in an audio preprocessor - Page 1
Forum section: electronics / beginners

author: orbitalframe7
author_rank: Newbie
timestamp: June 09, 2023, 09:36:58 pm
content: I have located a source of coil whine on an Outlaw Audio preprocessor. It appears to be the transformer or an inducter but I can't find the company who made the transformer. I found some in aliexpress calling them Ferrite Core Switching Power Supply Transformersbut in digikey was only able to find 1 in the fixed inductor category however seems to be the wrong type. Also to add, the coil whines only when the unit is off/stand by. When it turns on it is quiet.Should I epoxy the offending component?Should I just sound dampen the unit?I also noticed the leads are 4+4 however the board can take 4+6. If I do get a replacement would I solder 4+4 by cutting off the unnecessary leads?How would I find the right type by using a multimeter? Do I check for resistance or Ohms or something like that?

author: srb1954
author_rank: Super Contributor
timestamp: June 09, 2023, 10:53:00 pm
content: Quote from: orbitalframe7 on June 09, 2023, 09:36:58 pmThis is a mains operated switching power supply. Do not mess around with it unless you know what you are doing as you run the risk of destroying the circuitry or even giving yourself an electric shock.Do not change the transformer with anything but anexactequivalent. You can perhaps search for the transformer part number but this might be a custom transformer in which case you won't be able to buy one on the open market and will have to source one from the equipment manufacturer.The noise you are hearing might be perfectly normal for this type of supply. See p8 of the Power Integrations TNY254 datasheet for a description of this phenomenon.

author: orbitalframe7
author_rank: Newbie
timestamp: June 10, 2023, 01:07:21 am
content: Got it, thanks for the information.
Coils on small seperate fiberglass boards  - Page 1
Forum section: electronics / beginners

author: Sjokolade
author_rank: Regular Contributor
timestamp: October 29, 2016, 10:32:06 pm
content: Why are some coils mounted on to small seperate fiberglass boards before they are fitted to circuit boards ?Less coil whine ? easier to fit ?

author: sahko123
author_rank: Frequent Contributor
timestamp: October 29, 2016, 10:36:11 pm
content: Quote from: Sjokolade on October 29, 2016, 10:32:06 pmthis may be that the coils are tuned or preselected.

author: amyk
author_rank: Super Contributor
timestamp: October 29, 2016, 10:56:38 pm
content: It keeps the leads aligned for easy insertion.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: October 29, 2016, 11:46:06 pm
content: Quote from: amyk on October 29, 2016, 10:56:38 pm^There may also be reasons for insulation/isolation, which the green square in the second pic is doing. Keeps the wires away from the components on the facing PCB.The one on the right, second pic, might also have insulation between windings. This is common with common mode chokes:http://www.digikey.com/product-detail/en/triad-magnetics/CMT-8120/237-1373-ND/2783628They may also be molded in, likehttp://www.digikey.com/product-detail/en/wurth-electronics-inc/744834101/732-3402-ND/2794422Or they simply use spacer tape:http://www.digikey.com/product-detail/en/bourns-inc/8107-RC/M8902-ND/775441Tim

author: station240
author_rank: Unknown
timestamp: October 31, 2016, 04:56:52 pm
content: Also consider magnetic coupling, by using separate and differently orientated PCBs, they can reduce the interaction between unrelated parts of the circuit.

author: BravoV
author_rank: Super Contributor
timestamp: October 31, 2016, 05:32:55 pm
content: Quote from: amyk on October 29, 2016, 10:56:38 pmAlso if you watch the windings, all are secured/soldered/glued to that piece of plastic, without it, the coil will unwind or get loose before they were assembled into the board, cmiiw.
Coin cell battery capable of 100mA pulse current - Page 1
Forum section: electronics / beginners

author: Jester
author_rank: Frequent Contributor
timestamp: November 28, 2016, 11:17:54 pm
content: Most (possible all) coin cells that I have looked at have fairly high internal resistance that limits output current to a few ma at best. I have a WiFi application that will require closer to 100mA for short pulses during intermittent transmit bursts.Is anyone aware of a coin cell that can deliver high pulse current even if overall battery life is short?I was using a low current Econais EC32L13 Wi-Fi chip however this part is now obsolete, I have not found anything close to the original device form a current requirement perspective (7ma)

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: November 29, 2016, 12:38:55 am
content: The lithium-ion variants, e.g. Lir2032, Lir2450 can put out decent currents - should manage 100mA easily - certainly the 2450. The 3.7v nominal is also better for nominally 3.3 or 3.0v loads as it gives more headroom.Alkaline button cells (e.g. LR44) are also a lot better then non-rechargeable lithium for current capability.

author: timb
author_rank: Super Contributor
timestamp: November 29, 2016, 01:06:10 am
content: Check out Illinois Capacitor'snew line of RJD coin cells.They can do over 100mA pulse no problem, without damage to the battery. They're also higher capacity than traditional rechargeable coin cells. Apparently, traditional rechargeable coin cells actually use a tiny square cell inside of the round casing, which leaves area unused. IC have figured out a process to produce cells that fill the casing, which increases the capacity and lowers ESR.There's alsomuRata's UMAL series, however they're not coin cells (though they're *very* small). The capacity is pretty low at 12mAH, but they can handle 10C discharge.Finally, you could use your old fashioned LiR coin cell and combine it with a supercap. Basically, you'd have a circuit that slowly charged the SC up between transmit pulses. The SC would handle the instantaneous current demands of the WiFi module instead of the battery.
A collection of electronic introduction articles on the web - Page 1
Forum section: electronics / beginners

author: btfdev
author_rank: Contributor
timestamp: July 24, 2012, 08:33:20 pm
content: Hello readers,Posting our favorite collection of electronics links here, it is great to view it as an introduction & quick start article.http://www.binarytaskforce.com/Weblog/2012/07/23/intro-electronics/There are some recommended RC model related electronic topics at the end. Good read !!!Enjoy. Team BTF.
Collector  - emitter breakdown voltage of BJT - Page 1
Forum section: electronics / beginners

author: chikenlover
author_rank: Newbie
timestamp: July 07, 2015, 07:04:53 am
content: Hello everyone!Simple question - does the collector emitter breakdown voltage actually decreases with increased collector current? Or is it just the dissipated power that burns the transistor ?

author: Simon
author_rank: Unknown
timestamp: July 07, 2015, 07:24:28 am
content: I think your confusing max voltage (breakdown) with Vce during operation.Breakdown voltage usually refers to the maximum voltage you can apply to the transistor before it is damaged. This mostly applies to when it is off as when it is on the voltage drop is low and any applied voltage will fall on the load mostly unless the transistor is part on. Think of it as a mechanical switch. If you apply a voltage to it when it's open through a load the full voltage falls across the switch and it needs to be rated for it. Once closed it's just a conductor so low resistance and all of the voltage falls to the load.

author: Alexei.Polkhanov
author_rank: Frequent Contributor
timestamp: July 07, 2015, 07:35:40 am
content: By collector current do you mean reverse saturation current? I think with increase of temperature reverse breakdown voltage will be going up to and with it reverse saturation current will also go up. At least this is how it is for diodes in reverse. For avalanche diodes and zener diodes this behavior is different - see this link for example:http://conceptselectronics.com/diodes/effect-temperature-diode-characteristics/. So I am guessing collector-emitter breakdown will be more like avalanche breakdown.
Collector Feedback biasing - Page 1
Forum section: electronics / beginners

author: fady232
author_rank: Contributor
timestamp: May 06, 2025, 10:52:51 am
content: Hello all,i was building this circuit that its an amplifier made with bjt, i had some questions before simulating it.First of all what's the purpose of this feedback? and how i choose the right values for RC and RB?.Like usually when i build this circuit what im trying to obtain? what data i got?what i wanna obtain is a proper ib for my load by sizing RB, and what for the current that gonna drive the load? where is the load gonna be connected? at emitter ( in parallel ) or to collector?Thanks for the help

author: PGPG
author_rank: Frequent Contributor
timestamp: May 06, 2025, 04:14:58 pm
content: I don't know how to read parameters of your V1 source (I don't use Spice) but as there are no value expressed in mV or uV I suppose it will not work as you expect.Vbe can't be practically bigger than 0.7V.If transistor had beta=100 you will not need the feedback biasing as without feedback you will be able to set working point as you wish.But if beta varies from 100 to 600 feedback helps to get reasonable working point.You should also understand that typically DC biasing is one subject and AC signal going through amplifier is the second subject.Typically = until you don't design DC amplifier.
Coloured solder mask has disappeared from ebay? (Solved) - Page 1
Forum section: electronics / beginners

author: Zepnat
author_rank: Regular Contributor
timestamp: February 19, 2014, 09:46:13 pm
content: Hi, I'll be needing some more solder mask ink in the distant future, there used to be loads in all colours on ebay.White, red and green I search for but there's only green now, it is puzzling does anyone know what's happened to the other colours...thankshttp://www.ebay.co.uk/sch/i.html?_trksid=p2050601.m570.l1313.TR0.TRC0.H0.Xpcb+uv+paint&_nkw=pcb+uv+paint&_sacat=0&_from=R40

author: sleemanj
author_rank: Super Contributor
timestamp: February 19, 2014, 10:02:28 pm
content: That stuff is such a pain the ass to use (and get a good result) for anything more than a couple cm square. That said I checked ebay.com.au and there is no shortage, it just seems to be ebay.co.ukRed (the only colour I've really had much luck with, I had a 10cc):http://www.ebay.com.au/sch/i.html?_odkw=PCB+UV+Curable+Solder+Mask+Repairing+Paint+Blue+100g++From+China++red&_osacat=0&_from=R40&LH_PrefLoc=2&_trksid=p2045573.m570.l1313.TR0.TRC0.H0.XPCB+UV+Curable+Solder+Mask+red&_nkw=PCB+UV+Curable+Solder+Mask+red&_sacat=0White (god this is a pig, never had a good result, I have a 100g):http://www.ebay.com.au/sch/i.html?_odkw=PCB+UV+Curable+Solder+Mask+red&_osacat=0&_from=R40&LH_PrefLoc=2&_trksid=p2045573.m570.l1313.TR0.TRC0.H0.XPCB+UV+Curable+Solder+Mask+white&_nkw=PCB+UV+Curable+Solder+Mask+white&_sacat=0Blue (also a prick, 100g, I'm pretty sure this is just the resist stuff, unlike the others it "dries"):http://www.ebay.com.au/sch/i.html?_odkw=PCB+UV+Curable+Solder+Mask+white&_osacat=0&_from=R40&LH_PrefLoc=2&_trksid=p2045573.m570.l1313.TR0.TRC0.H0.XPCB+UV+Curable+Solder+Mask+blue&_nkw=PCB+UV+Curable+Solder+Mask+blue&_sacat=0Black (not tried)http://www.ebay.com.au/sch/i.html?_odkw=PCB+UV+Curable+Solder+Mask+blue&_osacat=0&_from=R40&LH_PrefLoc=2&_trksid=p2045573.m570.l1313.TR0.TRC0.H0.XPCB+UV+Curable+Solder+Mask+black&_nkw=PCB+UV+Curable+Solder+Mask+black&_sacat=0

author: Zepnat
author_rank: Regular Contributor
timestamp: February 19, 2014, 11:03:48 pm
content: Thank you, they have a huge list of excluded countries and I now realise why it didn't show up on eBay UK.Agreed it is awful messy stuff, I used the clear film from the resist to apply the ink, it is shiny and peels off ok, but the person who shipped the resist to me just stuffed it in a padded envelope and the creases in the clear film show on the solder mask!http://www.ebay.com.au/sch/i.html?_odkw=dry+film+photoresist&_osacat=0&_from=R40&LH_PrefLoc=2&_trksid=p2045573.m570.l1313.TR0.TRC0.H0.Xdry+film+photoresist+sheet&_nkw=dry+film+photoresist+sheet&_sacat=0Thanks for the tip on the blue paint drying, that's worth knowing.
Colpitts Oscillator - Page 1
Forum section: electronics / beginners

author: interoth
author_rank: Contributor
timestamp: July 06, 2012, 05:26:31 pm
content: I was looking for a Colpitts Oscillator designwhen I found a decent oneOn the schematic it has some values listed with a "e-6", what does that stand for? I am assuming it's a character the computer does not have. Am I also right in assuming that "100p" is 100pF?

author: madworm
author_rank: Frequent Contributor
timestamp: July 06, 2012, 05:29:10 pm
content: 0.15E-6 = 0.15 * 10^(-6) = 150n

author: Simon
author_rank: Unknown
timestamp: July 06, 2012, 05:38:04 pm
content: they are basically saying micro (1/1'000'000) 0.1 micro would in effect be 1 x 10 to the -7

author: IanB
author_rank: Super Contributor
timestamp: July 06, 2012, 07:39:39 pm
content: Quote from: interoth on July 06, 2012, 05:26:31 pmI would have my doubts about it being "a decent one" given the lack of attention to detail on the drawing. It could be that someone has just hacked up the circuit in LTspice and checked that the simulation worked. The circuit may be good, perhaps, but I would also suggest you be very discriminating and don't just take circuits like this at face value. Is there a comprehensive discussion and description of how it works accompanying the diagram?As you have read above, LTspice allows you to enter standard abbreviations for engineering notation. So for instance, instead of entering 0.1e-6 for a capacitance value, you can enter "0.1u" which is how you will usually find such a capacitor described. Likewise "0.15u" for L1 would indicate a value of 0.15 uH. Since we don't find the Greek letter mu on our keyboards we can use "u" instead.In case you have not come across scientific notation and/or computer arithmetic yet, it is common in the scientific world to write large and small numbers in a compact notation. So for instance, instead of writing 0.0000015 (how many zeroes?) we can write 1.5 x 10-6. Computers don't have a convenient way of displaying "1.5 x 10-6" so instead they show it as "1.5e-6" (or 1.5E-6).
Controll voltage - without comparator? (Isolated PSU) - Page 1
Forum section: electronics / beginners

author: rentner
author_rank: Regular Contributor
timestamp: September 14, 2013, 07:18:22 pm
content: I was working on a HV power supply. It will convert a HVDC to HVDC. It does not use any PWM for simplicity. I actually find it quite unusable, to check for the correct output voltage through a comparator and optocoupler, to switch off the Converter, if a voltage is exceeded.Is there a way to trigger an optocoupler from far over 100V without damaging AND getting inaccuracy? I was testing it on LTSPice with a Zener but found out, that small changes in Temperature will change the output over a range of +/-20V - only 1-2V was allowed, so I was going for a comparator - actually this sucks, because it needs a low voltage rail completely isolated wich gives it more work to do and has higher cost. Is there a more simple way, to turn on an optocoupler through reaching a defined Voltage? It will be fixed - there is no need for variation in the control voltage. Since the output is isolated from the Input, a direct feedback wire won't work. Optocoupler is a must!But I realy hate, to use a comparator and extra supply rail.Edit:Is it possible, to get accurate voltages not more than 2V appart from each other with standart low precision Zener Diodes?And since 5% Zener diodes are not accurate, will it work good, if I hook some in series, maybe?i.e.: 60V Zener Diode could have 58V - add a 2V Zener - would that work? The problem is, what about different recovery times? Will that even matter?

author: edavid
author_rank: Super Contributor
timestamp: September 14, 2013, 08:22:39 pm
content: This is easily done using the TL431 as a comparator. Here's some good reading for you:http://www.google.com/search?q=tl431+optocoupler+feedback
Comparator work in sawtooth generator - Page 1
Forum section: electronics / beginners

author: Sabrum
author_rank: Newbie
timestamp: June 13, 2018, 02:56:09 pm
content: Hi everyone. I'm building a saw generator with an exponential converter to control the frequency. I need to get as little saw front as possible. But the comparator LM311 gives out a smooth voltage at the beginning, and then quickly resets it. (1-2 in attachments)On another forum people said to use a PNP transistor and the other input of the comparator. It works in the simulator (in reality, I haven't soldered it). Also they said that i can remove PNP and use the built-in transistor LM311 for switching, but did not say how. Does anyone know how to do that? (3-4 in attchments)

author: Benta
author_rank: Super Contributor
timestamp: June 13, 2018, 04:09:30 pm
content: Your circuit looks very complex to me, and I don't see a necessity for the complexity.For a sawtooth generator, you basically need a constant current source charging C4, this will give you a linear ramp voltage. When this voltage crosses a certain threshold, the LM311 output transistor turns on and discharges C4.By defining a hysteresis in the LM311 (positive feedback) you'll have a nice sawtooth wave.Varying the frequency can be done by making the current source adjustable.In short, you need the LM311, and handful of resistors and caps, an adjustable current source, and a buffer amp for boosting the voltage over C4.

author: w2aew
author_rank: Super Contributor
timestamp: June 13, 2018, 08:32:13 pm
content: I did a video a few years ago that showed a sawtooth/triangle waveform generator using constant current sources, a diode switch and a comparator. You could "start" with this, and modify it to meet your requirements:

author: Sabrum
author_rank: Newbie
timestamp: June 13, 2018, 09:38:47 pm
content: Quote from: w2aew on June 13, 2018, 08:32:13 pmI have already made my generator using the 74hc132 logic chip instead of the comparator. Here only one minus - noise from the logic and a small pedestal at the top of the saw. I thought I made a compromise until you showed me your video. I have not seen such schemes on the internet before. Thanks!Is it possible to get from this scheme a front less than 100ns? Or just connect one side of switch to ground, instead of current source? And the frequency I can adjust by changing the current in one of the current arms?
Combination of TT and TN-C-S (PME) earthing systems a no-no? - Page 1
Forum section: electronics / beginners

author: fubar.gr
author_rank: Unknown
timestamp: March 05, 2016, 05:25:00 pm
content: Why some jurisdictions prohibit combining TT and TN-C-S earthing systems?If my house is on a TN-C-S system, how can adding a few earthing electrodes (TT) going to hurt?So far I haven't gotten a convincing explanation for this prohibition.

author: dmills
author_rank: Super Contributor
timestamp: March 06, 2016, 02:20:09 am
content: If the combined neutral/earth (The C in TN-C-S) comes adrift between you and the upstream transformer, then the entire neutral current will try to return to the transformer via your earth rods (and the earthing local to the transformer).You can (usually, local rules dependent) do it, but it may take a earth conductor very much larger then you would expect.It is not your neutral current that could flow in this bond, it is the vector sum of the neutral currents from all the loads downstream of the break.Regards, Dan.
Combining 4 Ohm & 8 Ohm speakers - Page 1
Forum section: electronics / beginners

author: made2hack
author_rank: Frequent Contributor
timestamp: April 11, 2019, 05:26:40 pm
content: Hi all,I have this old pair of small shelf speakers that I want to freshen up. They have a 4 Ohm / 25 Watt mid range speaker. I am adding to it an 8 Ohm / 40 Watt tweeter. What would be the ideal way to connect the two since they are of different impedance?I am using an off the shelf 3.3Khz / 12dB / octave RCL filter passive crossover.Should I connect in parallel? Series? Any pros / cons? Or should I perhaps add a 4 Ohm resistor in series to the Mid range and then parallel the two speakers?Thanks,

author: grifftech
author_rank: Frequent Contributor
timestamp: April 11, 2019, 06:26:27 pm
content: just parallel them, the mid range speaker will take 2 times as much power as the tweeter.

author: soldar
author_rank: Super Contributor
timestamp: April 11, 2019, 07:34:17 pm
content: You might want to install a passive crossover filterhttps://en.wikipedia.org/wiki/Audio_crossover#Passive

author: soldar
author_rank: Super Contributor
timestamp: April 11, 2019, 08:33:30 pm
content: Oops. Sorry. My bad.

author: Audioguru
author_rank: Super Contributor
timestamp: April 12, 2019, 01:50:22 am
content: What impedance speakers is the crossover network made for? If it is for 4 ohm speakers then simply add an 8 ohm resistor parallel with the 8 ohm tweeter.No woofer speaker?

author: Zero999
author_rank: Super Contributor
timestamp: April 13, 2019, 06:02:29 pm
content: Speakers don't have a flat, resistive 8 or 4 Ohm impedance at all frequencies. Does anyone know whether passive crossover networks are designed to take this into account? If so, then changing the speaker, will affect the frequency response.I think you should try to stick to the same kind of speaker, both physically and mechanically to stand the highest chance of it giving good sound quality.

author: Audioguru
author_rank: Super Contributor
timestamp: April 13, 2019, 06:27:24 pm
content: Quote from: Zero999 on April 13, 2019, 06:02:29 pmYes an impedance correction Zobel Network is used to flatten the inductive impedance of a woofer and flattens the resonant peak impedance of a tweeter.

author: made2hack
author_rank: Frequent Contributor
timestamp: April 14, 2019, 03:55:29 pm
content: The crossover is for an 8Ohm load.Thanks,
Combining bridge rectifier outputs for higher combined Voltage - Page 1
Forum section: electronics / beginners

author: SkrillBill
author_rank: Regular Contributor
timestamp: November 24, 2017, 03:52:00 pm
content: Working on designing a very basic powersupply (4 outputs; 3 fixed 1 variable) out of some voltage regulators.Supply will be 1Primary/2Secondary transformer. 115-120v@60hz/ 16v on each secondary. Secondaries are each fed into a rectifier. One rectifier will feed the 5 and 12v regulators, but i need the combined output for the 24 and variable. What is the proper way to tie the outputs of the rectifiers together? Here is the schematic (digikey scheme-it):https://www.digikey.com/schemeit/project/powersupply-v1-1-GDI647G303I0/Thank you

author: trys
author_rank: Regular Contributor
timestamp: November 24, 2017, 05:00:37 pm
content: Duplicate post:https://www.eevblog.com/forum/beginners/4-output-(but-very-basic)-power-supply/

author: Simon
author_rank: Unknown
timestamp: November 24, 2017, 05:02:56 pm
content: Please don't post the same question multiple times, it's poor etiquette.
Combining Mux's - Page 1
Forum section: electronics / beginners

author: sci4me
author_rank: Regular Contributor
timestamp: July 03, 2013, 08:31:08 am
content: Hey guys, noob question: I have to mux into 69 OR MORE (it depends on the final design) and i can only use mux's with 5 bits selection. So basically each mux has 32 outputs and i need 69 or more. If anyone can tell me exectly how I need to connect them together, it would be greatly appreciated! Thanks!EDIT: Like an idiot, i wrote demux instead of mux. :|

author: dfmischler
author_rank: Frequent Contributor
timestamp: July 03, 2013, 12:12:31 pm
content: I'm afraid it's not clear to me exactly what you want to do. So please, tell us more (maybe a lot more) so we can help.

author: Skimask
author_rank: Super Contributor
timestamp: July 03, 2013, 12:20:58 pm
content: Quote from: sci4me on July 03, 2013, 08:31:08 amhttp://www.catb.org/esr/faqs/smart-questions.html

author: mrflibble
author_rank: Super Contributor
timestamp: July 03, 2013, 12:33:23 pm
content: Given the rather curious design constraint I'd almost guess homework is due. At an rate, you can cascade mux stages. Google "cascading mux". And if you inadvertently actually meant demux, then you know what to google instead.
Combining two ac sources rectifier - Page 1
Forum section: electronics / beginners

author: Vindhyachal.takniki
author_rank: Frequent Contributor
timestamp: April 29, 2015, 06:38:53 am
content: 1. I have two ac sources(from mains & generator) & have to run a circuit from it for which I need dc supplyI had connected a bridge rectifier to each source. After that each output is shorted.2. Circuit is attached. It Actual circuit also has regulator & othe stuff, which i didn't show, I had only connected Rload & C.3. There may be three cases: Only main available, only generator available, or both are available.4. Is the circuit attached is safe.5. I think problem may arrive when both ac sources are available.Also it could be one may be at different angle then other. Like if first ac source have crest, other couls have trough or at some phase from each other.

author: richard.cs
author_rank: Super Contributor
timestamp: April 29, 2015, 06:51:09 am
content: If you have a small generator with floating windings then it will work, most larger generators include a neutral earth bond and that would be bad because the mains is also earth referenced. See what happens in your simulation if you ground one side of each source.

author: MMDuino
author_rank: Regular Contributor
timestamp: April 29, 2015, 09:32:56 am
content: See next circuit with 2 * 220Vac relays, it's safe....