hybridfree/eevblog-posts huggingface dataset:
What kind of connector is this? - Page 1
Forum section: electronics / beginners

author: silviasol
author_rank: Regular Contributor
timestamp: May 09, 2017, 06:35:47 pm
content: I would think it is a jst connector but not finding any that are bigger then 2.5mm. Looks to be a 3 to 4mm type of jst. This is on a sega game gear handheld console I am repairing.http://imgur.com/a/yM3lL

author: dSolder
author_rank: Newbie
timestamp: May 10, 2017, 06:59:11 am
content: In the sega game gear service manual I found online it had it as: "CONN 6P FOR GG 188094-6 AMP" I couldn't find anything online about it though.

author: silviasol
author_rank: Regular Contributor
timestamp: May 13, 2017, 02:36:41 am
content: Thanks. I had a spare 2mm jst that I used. Just cut all the side plastics, will not lock but holds ok.
What kind of connector is this? - Page 1
Forum section: electronics / beginners

author: hanndoddi
author_rank: Contributor
timestamp: November 04, 2013, 05:03:47 pm
content: Any one know what this connector is called or were to find it. I have been trying ti google it but don't rely know what to look for.the connector is on a deagan vibraphone and looks to be for the 115 volts.please ask if there is anything more i can tell you

author: rexxar
author_rank: Frequent Contributor
timestamp: November 04, 2013, 05:39:07 pm
content: First, use a better image compression scheme. Try jpeg, it's nice.That looks like one of those twist-lock connectors. It looks like it has two curved connectors and a center pin? Looks sort of like a NEMA L1 with a ground pin. Never seen one like that before.EDIT: Actually, I think it's a Leviton ML2.

author: Kryoclasm
author_rank: Regular Contributor
timestamp: November 05, 2013, 01:49:42 am
content: Cooper twist lock.2 pole 3 wire.NEMA ML3 Midget7486Nhttp://www.nationalsupplyonline.com/Cooper_Wiring_Devices15.html

author: hanndoddi
author_rank: Contributor
timestamp: November 05, 2013, 11:08:54 pm
content: Thank you very much Kryoclasm and rexxar very helpfull.I'm not really familiar with image compression scheme I just used paint, I will definitely try to do better next time and try jpeg thanks for the suggestion.Best wishes from Iceland!

author: JOERGG
author_rank: Contributor
timestamp: November 05, 2013, 11:24:56 pm
content: I use Image Resizer for Windows, because it is so easy to use.http://imageresizer.codeplex.com/

author: hanndoddi
author_rank: Contributor
timestamp: November 05, 2013, 11:33:18 pm
content: That looks nice does it allow you to chose the size of the file?could you for example tell the program to scale it down to 1000KB?

author: hanndoddi
author_rank: Contributor
timestamp: November 06, 2013, 12:04:07 am
content: lets see if this photo looks better now, I installed the image resizer it is very fast and easy thank you joregg.

author: GreyWoolfe
author_rank: Unknown
timestamp: November 09, 2013, 10:55:12 pm
content: Irfanview is a nice, free program that lets you scale your image re-sizing.Tom, NW0LF

author: Six_Shooter
author_rank: Regular Contributor
timestamp: November 09, 2013, 11:54:00 pm
content: Back when I was a traveling carny, we had those all over the rides for lighting and some control systems of the rides.
What kind of driver suitable for this bipolar motor? - Page 1
Forum section: electronics / beginners

author: nour
author_rank: Frequent Contributor
timestamp: March 19, 2016, 06:16:52 pm
content: Hi I want to buy this motor for my cnc building and I want to make the driver myselfI want to know how much voltage would be considered suitable for driving this motor?it says in the description it is 100VAC, I have looked everywhere around the internet to confirm this but couldn't find any further data regarding the voltage that I can use with this motor?EDITthe motor page on TME.comhttp://www.tme.eu/en/details/103h7823-1741/electric-motors/sanyo-denki/sorry forgot to add the link

author: michaeliv
author_rank: Frequent Contributor
timestamp: March 19, 2016, 06:23:07 pm
content: missing link / doc?
What kind of header is this? - Page 1
Forum section: electronics / beginners

author: metrologist
author_rank: Super Contributor
timestamp: August 02, 2020, 06:01:58 pm
content: I will need to find the male side on a ribbon cable. What should I look for?

author: fcb
author_rank: Super Contributor
timestamp: August 02, 2020, 06:03:55 pm
content: looks like a "micromatch", try searching "Micro-MaTch"

author: metrologist
author_rank: Super Contributor
timestamp: August 02, 2020, 06:59:11 pm
content: That's it! $2 plus $15 shipping, from Italy. Every other header on this card uses standard 2-row pin headers.

author: tooki
author_rank: Super Contributor
timestamp: August 02, 2020, 08:15:40 pm
content: Quote from: metrologist on August 02, 2020, 06:59:11 pmWhy not just add them to your next Digi-Key, Mouser, or Farnell order? This isn’t a rare, exotic part.
What kind of log taper pot is the correct one? - Page 1
Forum section: electronics / beginners

author: BeBuLamar
author_rank: Super Contributor
timestamp: May 21, 2025, 11:46:38 am
content: I built a headphones amp and it works fine. I used a gang 10 turn linear pot and it works but of course the sound level isn't any where linear to the pot position. I want to replace it with a simple 3/4 turn 2 gang pot with log taper. However they have different kind of taper so which one is the right one for this application?

author: tszaboo
author_rank: Super Contributor
timestamp: May 21, 2025, 12:06:15 pm
content: Something like this:Anything resembling log will work usually good enough. You can also modify them to your liking if you place a load on the taper,.

author: SteveThackery
author_rank: Super Contributor
timestamp: May 21, 2025, 12:20:08 pm
content: Actually there's a heck of a lot of tapers: see the attached pic.Honestly, it really doesn't matter at all. Any so-called log taper will be loads better than a linear pot - you probably wouldn't notice any difference between them. You just need to flatten down the early stages of the potentiometer's travel, and any log pot will do that.Looking at the curves, maybe a 10A might be good. Or a 4B, although notice the boosted part of the curve higher up. And remember, the charted curves are only true when the pot is not loaded by the following circuitry.Go for a good quality pot, and don't worry too much about the exact log curve. You'll be pleased whichever you get, but make sure it's from a decent supplier and not some ebay rubbish.

author: macboy
author_rank: Super Contributor
timestamp: May 21, 2025, 05:07:26 pm
content: You can create a pseudo-log taper from a linear taper pot by placing a resistor from the wiper to ground. For a 100k linear pot, try something around 10k to 20k for this wiper resistor. The resulting response won't be very mathematically similar to a true log taper, but it will work well for audio. Another benefit is that you may get better channel to channel tracking than a true log pot, since it is easier to manufacture an accurate linear taper than an accurate log taper.One downside is that the impedance to ground of the modified pot is now not constant and depends one the wiper position.

author: Gyro
author_rank: Super Contributor
timestamp: May 21, 2025, 07:42:40 pm
content: ^ Probably the most accurate (in terms of channel balance) approach. True log taper pots are very rare - audio taper pots are basically manufactured by using two linear taper compositions on the same track, first a low resistance, then a higher resistance section. I think the only differences are in the transition region where the two sections blend. There are obviously going to be mechanical and composition tolerances in this region which can cause a shifts in channel balance.You won't get this with a linear pot and a 'non-linearizing' load resistor.On theAnother downside though is that the wiper is passing significantly more current (ideally you wouldn't pass any wiper current) which could lead to noise and additional distortion.
What kind of motor is this? - Page 1
Forum section: electronics / beginners

author: QsiMoto
author_rank: Newbie
timestamp: October 30, 2024, 03:17:32 pm
content: My LLano laptop cooler stopped working. The control board showed no real damage so I figured it was not a voltage issue...but while I was testing it I broke a flush mount capacitor off and killed the control board. I decided to rescue the motor using the original DC power supply that came with the cooler, nothing happened, no motor spin. At first I figured it was just a cheap motor as it had three wires that I assumed were red for voltage, black for return/ground, and the third for the tachometer. With this assumption I first tested for ohms using a multimeter and everything looked good, then I tried the old school "Spin the motor" to see if it would generate voltage but it produced no voltage output on any of the wires. At this point I considered it a lost cause, as the motor has no identifying marks or stickers to indicate manufacturer, polarity, or any other defining factors. I decided knowledge was worth more than another "dead" motor sitting on the shelf, so I disassembled the motor, which unfortunately breaks it as the bracket it was mounted into was a press fit. Found a lot more than what I was bargaining for. It has, for me, a pretty complex circuit card on the back.Could anyone tell me what type of motor this is, and point me in the right direction to learn more about working on them? .

author: QsiMoto
author_rank: Newbie
timestamp: October 30, 2024, 05:03:28 pm
content: Thank you for the informative video, It gave quite a bit of info that I was completely unaware of. I will see what I can learn from my mistakes. Thank you, and all of the others who post to this board....it gives a old newbie like me a little hope to be able to actually fix something.
What kind of motor is this? - Page 1
Forum section: electronics / beginners

author: Adhith
author_rank: Frequent Contributor
timestamp: February 01, 2021, 04:52:51 am
content: Hello guys,I recently came across a very particular motor (the pic in the attachment) which I think is a type of BLDC. I came to know that, this motor is used along with an impeller for portable powered Air respiratory system. I would like to read more about this type of motor, its controlling board and possibly, make a good use of this motor in one of my DIY project. However, I don’t know what to search for and hence I'm not getting much info on this. Could someone help me out?Thank you in Advance!

author: beanflying
author_rank: Super Contributor
timestamp: February 01, 2021, 05:04:16 am
content: If you were to crack it open you will find some hall effect sensors . So this sort of thing.https://www.assemblymag.com/articles/94866-how-to-select-hall-effect-sensors-for-brushless-dc-motorsGenerally most for most R/C applications (not cars) the hall effects are no longer used on the speed controllers. So if you were to buy an R/C controller simply just power it and ignore the hall wiring.

author: Gyro
author_rank: Super Contributor
timestamp: February 01, 2021, 10:43:36 am
content: Although, if you do use the hall sensors, you will get much better low speed performance.

author: beanflying
author_rank: Super Contributor
timestamp: February 01, 2021, 10:47:35 am
content: Yep thats why the Cars still use them better torque and speed control

author: Adhith
author_rank: Frequent Contributor
timestamp: February 02, 2021, 06:08:16 am
content: Thank you for your help!. What I could now understand is that, this is a typical BLDC motor coupled with hall effect sensor. So we could run the motor with a normal 3 wire BLDC speed controller if we could skip the hall wiring.

author: Adhith
author_rank: Frequent Contributor
timestamp: February 02, 2021, 06:17:48 am
content: Quote from: beanflying on February 01, 2021, 05:04:16 amThank you for your help!. What I could now understand is that, this is a typical BLDC motor coupled with hall effect sensor. So we could run the motor with a normal 3 wire BLDC speed controller if we could skip the hall wiring.

author: Adhith
author_rank: Frequent Contributor
timestamp: February 02, 2021, 06:18:33 am
content: Quote from: Gyro on February 01, 2021, 10:43:36 amThank you for your comment. If I need to use the hall sensor as well, what type of controller board I should look into?

author: Adhith
author_rank: Frequent Contributor
timestamp: February 02, 2021, 06:19:07 am
content: Quote from: beanflying on February 01, 2021, 10:47:35 amGreat! thank you. If you have any links to any articles or projects using such motor, would be great help.

author: beanflying
author_rank: Super Contributor
timestamp: February 02, 2021, 06:19:45 am
content: Quote from: Adhith on February 02, 2021, 06:15:27 amUse the top Right search box and Google search the site (example)https://www.google.com/search?q=sensored+bdlc+controller&sitesearch=www.eevblog.comIt turned up a thread from last year which then went to this sitehttp://grauonline.de/wordpress/?page_id=3122
[Solved] What kind of PCB coating is this? - Page 1
Forum section: electronics / beginners

author: lain.cai
author_rank: Newbie
timestamp: March 12, 2014, 06:10:40 pm
content: I've found these black coatings on iPhone and Misfit Shine PCB; what are they and what are they used for?

author: free_electron
author_rank: Super Contributor
timestamp: March 12, 2014, 06:18:14 pm
content: That is underfill. They use that to mechanically strengthen the BGA to board mounting.

author: lain.cai
author_rank: Newbie
timestamp: March 12, 2014, 06:21:12 pm
content: Quote from: free_electron on March 12, 2014, 06:18:14 pmI see! Thank you so much
What kind of oscilloscope to use? - Page 1
Forum section: electronics / beginners

author: Kikenzi
author_rank: Newbie
timestamp: November 20, 2017, 11:50:48 pm
content: Hi there,Im novice in eev and i have question about what oscilloscope to buy i dont want to spend lot of money (i just begin learning about electronic). I saw this videowhere Dave connect oscilloscope to photodiode and measure and try to get a binary code. I want to start with something like this but i dont know what kind of oscilloscope is enough for this case: 20MHz or 100MHz and analog or digital..i need hellp with that.Thank you all for your advices.

author: Arjen_Arg
author_rank: Contributor
timestamp: November 21, 2017, 02:34:03 am
content: The biggest question here is: "What's your budget?" In any case, the king of bang per buck here is the Rigol DS1054z. At 400 U$S it's a 4 channel 50MHz scope, but it can be hacked to 100MHz.Check this awesome chart a user made:https://www.eevblog.com/forum/testgear/digital-oscilloscope-comparison-chart/

author: xani
author_rank: Frequent Contributor
timestamp: November 21, 2017, 06:32:39 am
content: You basically need to make a list of what you are doing now and what you might want to do in the future *then* start shopping around.While typical bench scope is very versatile tool it might be an overkill for you, or not the right tool.For beginner I'd advise to look into something like Analog Discovery 2, Dave has reviewed previous version:

author: macboy
author_rank: Super Contributor
timestamp: November 21, 2017, 03:29:26 pm
content: Quote from: Kikenzi on November 20, 2017, 11:50:48 pmFor this specific task, even a DS0138 (<$20 DIY kit) will do. The DS0138 is only single channel, 150 kHz, and 1 MS/s, but the signal is only roughly 40 kHz square wave. It will be easily resolved by that little scope. There is also the DS0112A which is 2 MHz bandwidth, 5 MS/s, and touchscreen interface. If it is all you can afford then it may be a good choice.
What kind of potentiometer do I need? - Page 1
Forum section: electronics / beginners

author: kvid
author_rank: Newbie
timestamp: June 30, 2018, 11:18:19 am
content: What kind of potentiometer do I need to control the current on the circuit in the attcahment. Would 47k logarithmic potentiometer do the job for up to 2.5A? What kind of potentiometer do in need to get to 3A?The attached snip is from the page 11.https://www.maxonmotor.com.au/medias/sys_master/root/8825195921438/367661-DEC-Module-24-2-Operating-Instructions-En.pdf

author: flynwill
author_rank: Regular Contributor
timestamp: June 30, 2018, 03:07:53 pm
content: You probably want a linear taper pot, not a log taper pot. The log pot will spend the majority of its rotation at either very close to zero speed or full speed depending on which way you wire it. Their example shows a 10k pot so clearly that will work fine. 47k will probably work but will be a bit non linear given the ~100k input impedance listed.

author: Simon
author_rank: Unknown
timestamp: June 30, 2018, 03:21:04 pm
content: Yes a linear pot. The the main of the very few reasons you would use a log pot is for volume control because our ears have a log response so using a linear pot as a volume control will make it hard to control the volume in exactly the same way putting a log pot on this controller that has a linear response. A log pot counter matches our ears "interpretation" of sound power giving an apparent linear response.The same is true of our eyes. Many sensors also have a non linear response (thermistor), the real world is never a linear one but most people devising circuits that talk to each other use a linear scale.

author: MatthewEveritt
author_rank: Unknown
timestamp: July 01, 2018, 10:45:02 am
content: I disagree, te resistance-current relationship of the values in that table is roughly exponential , a log pot would likely make for a far smoother control.

author: flynwill
author_rank: Regular Contributor
timestamp: July 01, 2018, 01:50:35 pm
content: Oops, you are correct, I completely mis-read the original poster's post and assume he was seeking a pot for the speed control.
What kind of power surge was it? - Page 1
Forum section: electronics / beginners

author: Berserk
author_rank: Contributor
timestamp: October 29, 2017, 06:54:04 pm
content: Hello, can anybody give me opinion about what kind of power surge may cause these damages?Was burned down power supply and variable frequency drive, input filters seems like can't do anythingAttachments: Scheme, photo of damaged devices

author: SeanB
author_rank: Super Contributor
timestamp: October 29, 2017, 07:45:02 pm
content: Looks like overvoltage, probably you had a momentary interruption of the neutral in a 3 phase system, and this phase was the lightest loaded one, or you had some other load inducing a short term ( around 1 second or so) high voltage spikes on the system on this phase, and this then exceeded the ratings of the controller chip, the snubber and the other small switching supply.Input filter is there to provide noise reduction, does not look like there were any MOV units there to provide robust overvoltage protection, which would at least have blown a fuse protecting the inverter from the high voltage.Could also have been caused by too high a ramp down or DC braking too large a load without a DC brake resistor attached, which would also result in a high voltage being impressed on the DC bus as well.

author: Berserk
author_rank: Contributor
timestamp: October 29, 2017, 08:09:30 pm
content: Burned power supply also have a varistor k320k1 in input circuit, and burned fuse

author: Zero999
author_rank: Super Contributor
timestamp: October 29, 2017, 09:33:46 pm
content: Quote from: Berserk on October 29, 2017, 06:54:04 pmThe input filter is not there to protect the device against damage. MOVs and gas discharge tubes can only protect it against short transient overvoltage, of limited energy. At higher energy levels, fuses blow, in order to protect against fire, even though destruction of the device is inevitable, at that point.
What kind of sensor can used for measuring tape - Page 1
Forum section: electronics / beginners

author: Vindhyachal.takniki
author_rank: Frequent Contributor
timestamp: October 03, 2020, 02:43:25 pm
content: I have application, where need to know how much elastic thread has been taken out from the device. Something like this:What kind of sensor is used here, to exactly measure how much thread is taken out in millimeter?I checked for rotary encoder but issue is thread rolls over spool, where circumference changes with each full turn, so that wont work i guess.

author: langwadt
author_rank: Super Contributor
timestamp: October 03, 2020, 03:00:25 pm
content: Quote from: Vindhyachal.takniki on October 03, 2020, 02:43:25 pmthe rotary encoder is the spiked wheel the string wraps around

author: Vindhyachal.takniki
author_rank: Frequent Contributor
timestamp: October 04, 2020, 07:08:53 am
content: Yes its not elastic thread.(wrong word), its string, same as used in video in post #1.I need to measure how much string moves out and in for some measurement.Since string will be used for measuring circumference so cannot use those metal type measuring inch,Is there any such readymade sensor aseembly availble which directly gives some digital/analog signal on how much thread moves in/out.

author: S. Petrukhin
author_rank: Super Contributor
timestamp: October 04, 2020, 09:00:53 am
content: Quote from: Vindhyachal.takniki on October 04, 2020, 07:08:53 amI think it is not necessary to measure the number of revolutions of the drum on which the thread is wound. It is necessary to rotate the string roller along which it moves linearly and it can be any encoder.
What kind of sensor do i need - Page 1
Forum section: electronics / beginners

author: littlebill
author_rank: Regular Contributor
timestamp: March 03, 2016, 02:31:31 am
content: Hello,I enjoy building projects using arduino's. would someone be able to tell what kind of sensor i could use to do the same thing as this unit?http://www.amazon.com/Reliance-Controls-THP108-PowerBack-Monitoring/dp/B003KREORA/ref=sr_1_1?ie=UTF8&qid=1456972098&sr=8-1&keywords=PowerBack+Utility+Power+Return+Alert

author: alho
author_rank: Contributor
timestamp: March 03, 2016, 03:19:25 am
content: Take a look at picture on second pagehttp://www.reliancecontrols.com/Documents/PowerBack%20Sell%20sheet%20Final.pdfIt's just a wire wrapped around one of mains cable that picks up mains frequency.

author: littlebill
author_rank: Regular Contributor
timestamp: March 03, 2016, 03:48:54 am
content: I realize that. I'm just wondering how I would detect that on a arduino

author: alho
author_rank: Contributor
timestamp: March 03, 2016, 06:35:46 am
content: C1 is not a capacitor it just represents capacitance between mains cable and wire wrapped around it. As voltage at mains cable rises relative to earth the capacitance C1 is charged by current flowing trough resistor divider which causes voltage across resistors.Note that it's EARTH not neutral phase of mains. Also mandatory WARNING that MAINS VOLTAGES are LETHAL, so don't believe what some random guy said on the internet is necessarily right.

author: danadak
author_rank: Super Contributor
timestamp: March 03, 2016, 03:02:56 pm
content: There are UL requirements that govern the isolation and alsoconsider the wattage needed for the R divider. Keep in mindthe divider cannot have arbitrarily large valued R's due to leakageof controller, and correspondingly too low values will sacrificenoise margin for controller input.Regards, Dana.

author: ade
author_rank: Unknown
timestamp: March 03, 2016, 03:38:10 pm
content: I think that device is battery operated so there would be no Earth connection.There should be a very small AC current on the looped wire. Maybe convert it to voltage (small resistor) then amplify it with an op-amp before feeding it to the ADC of the Arduino.For measurements of small currents usually you'll want to use a split-core Current Transformer or a Hall-effect sensor. For ideas see:CT:https://www.sparkfun.com/products/11005Hall effect:https://www.sparkfun.com/products/8882These are "non-invasive" so there should be no need to work directly with high mains voltages.(I'm not affiliated w/ sparkfun or know much about the products, they just showed up first on search).

author: littlebill
author_rank: Regular Contributor
timestamp: March 03, 2016, 05:47:37 pm
content: would a current sensor detect voltage presence though with no amperage going through the line?

author: ade
author_rank: Unknown
timestamp: March 03, 2016, 06:36:08 pm
content: Correction to what I said above, I just read the product manual and that device is grounded via a separate wire. So it can work via capacitive coupling as alho noted above.In any case, there will be current/amperage through the sensor wire.
What Kind of Silicone Coating is This? - Page 1
Forum section: electronics / beginners

author: KDoug
author_rank: Contributor
timestamp: October 08, 2018, 09:39:13 pm
content: Hi, brand new to this forum. I'll just state up front that I have limited knowledge on electronics but am willing to learn so I can repair my own stuff.I have a Dewalt DCS355 oscillating tool (power tool that cuts various materials through vibration) that I have made a repair. I had to take the circuit board out to make the repair and to do that I had to remove a lot of this "potting" type silicone that covered the board. I've looked around a good bit but most of the potting compounds I've seen online aren't silicone. The ones I have seen are usually a two part mixture and I'm not sure if that's what I need or not. Can y'all point me in the right direction of what I need. Attached are some photos.Thanks

author: KDoug
author_rank: Contributor
timestamp: October 08, 2018, 09:43:16 pm
content: It says I can't post pictures larger than 1000kb, how do I get around this?

author: robjodicarter
author_rank: Regular Contributor
timestamp: October 08, 2018, 09:49:51 pm
content: It's a waterproof coating, as long as you use a waterproof dielectric coating your good man.Sent from my PH-1 using Tapatalk

author: KDoug
author_rank: Contributor
timestamp: October 08, 2018, 10:00:44 pm
content: I have some MG Chemicals silicone conformal coating I just bought. The board was pretty much water proof, not sure why though. The tool makes a lot of vibration so I assumed it needed a lot of this coating to dampen it. I'm not just looking to spend money, so if you don't think I need it I'm ok with just using the conformal coating. I just want to repair it right.
What kind of stepper motor driver? - Page 1
Forum section: electronics / beginners

author: Eoiser
author_rank: Newbie
timestamp: February 19, 2014, 01:05:29 pm
content: Im going to buy a stepper motor for a project i have in mind.Its a bipolar stepper motorIm thinking about this one .TRINAMIC - QSH4218-51-10-049 - STEPPER MOTOR, 1.8DEG, 1A, 0.49NMhttp://no.farnell.com/trinamic/qsh4218-51-10-049/stepper-motor-1-8deg-1a-0-49nm/dp/1010727What driver should i buy with this one?

author: edmundopt
author_rank: Regular Contributor
timestamp: February 19, 2014, 04:50:04 pm
content: You mentioned BUY, not build one right ?You live at Norway, so I can't sugest my usual supplyer.but anyway, what are you going to connect the driver to? (microcontroler, breakoutboard,industrial)What will be the power supply voltage? (12/24/48)

author: Eoiser
author_rank: Newbie
timestamp: February 19, 2014, 05:42:38 pm
content: Quote from: edmundopt on February 19, 2014, 04:50:04 pmWhich ever one works..Quote from: edmundopt on February 19, 2014, 04:50:04 pmMicrocontroller, AVR to be exactQuote from: edmundopt on February 19, 2014, 04:50:04 pm12V

author: edmundopt
author_rank: Regular Contributor
timestamp: February 19, 2014, 07:09:09 pm
content: If you want a quick solution, for 1A, you can go for the really old L298 IC.If you want to learn a lot more, make yourself a dual MOSFET H Bridge with some sensing circuit.You have the excellent Microchip AN906.If you want to go really into stepper motor drives, check Microchip AN1307.there are other ways, you have to choose if you want to buy it and have it running tomorrow or if you want to learn and have it ready, next month, maybe

author: Eoiser
author_rank: Newbie
timestamp: February 19, 2014, 09:37:46 pm
content: Quote from: edmundopt on February 19, 2014, 07:09:09 pmThis is purely for educational purposes, so time is not a factor.I just want to learn as much as possible, and have a decent functional system.

author: Eoiser
author_rank: Newbie
timestamp: February 19, 2014, 09:54:06 pm
content: I see that the Duet board for the RepRap 3d printers use anA4982 Stepper driver

author: Eoiser
author_rank: Newbie
timestamp: February 21, 2014, 11:46:27 am
content: bump

author: jaxbird
author_rank: Frequent Contributor
timestamp: February 21, 2014, 11:55:21 am
content: Something based on DRV8811 or DRV8825 should work nicely with this motor.Or make your own circuit, just follow the directions in datasheet:http://www.ti.com/lit/ds/symlink/drv8811.pdfhttp://www.ti.com/lit/ds/symlink/drv8825.pdf
What kind of switch is what I need here? - Page 1
Forum section: electronics / beginners

author: dzarren
author_rank: Contributor
timestamp: November 19, 2021, 06:08:32 am
content: Hi there. What kind of switch would I be looking for to do the following?3 positions, but I'm switch 4 wires at once?Specifically what I want to do is use a single driver to drive 3 stepper motors non simultaneously. So I could switch to each of the motors individually.So out of my driver, the 4 wires go to power the motor, I want to be able to switch where the power goes.I've done something similar with 2 motors but how and where can I find a switch rhag will do three positions for me?

author: Ed.Kloonk
author_rank: Super Contributor
timestamp: November 19, 2021, 06:35:34 am
content: A 4-pole, 3 position rotary switch?https://www.jaycar.com.au/4-pole-sealed-pcb-rotary/p/SR1216

author: Nusa
author_rank: Super Contributor
timestamp: November 19, 2021, 06:38:23 am
content: How do you keep the stepper motors from moving when the power is removed? That's a key part of what the driver does, even when the motor is idle.

author: jpanhalt
author_rank: Super Contributor
timestamp: November 19, 2021, 11:08:19 am
content: If you want a toggle, search for 4P3T. Here is Mouser's offerings:https://www.mouser.com/c/electromechanical/switches/toggle-switches/?contact%20form=4P3T

author: vu2nan
author_rank: Contributor
timestamp: November 20, 2021, 10:53:15 am
content: A 4-pole, 3-way rotary switch may be used.Nandu.

author: Doctorandus_P
author_rank: Super Contributor
timestamp: November 20, 2021, 03:45:26 pm
content: Stepper motor drivers are cheap and have no movable parts.When you disconnect motors to a stepper motor while under power you also risk damaging the stepper motor driver with inductive voltage spikes.So I'd just go with multiple stepper driver IC's and give each motor it's own IC.
What kind of video cable is this? - Page 1
Forum section: electronics / beginners

author: Bushrod1996
author_rank: Newbie
timestamp: November 25, 2019, 12:54:55 am
content: I can’t find the answer and it’s driving me crazy. The video output from my brand-new (to me) Cadillac night vision camera (which has a Raytheon BST sensor) has three wires: yellow, green, and presumably ground. In the car they were attached to a connector, which has been severed and didn’t come to me with the camera. I will attach pictures.My extensive googling provided some facts:1. The output is NTSC composite.2. The yellow wire is “night vision video low signal.”3. The green wire is “night vision video high signal.”However, composite video cable like RG-6 and RG-59 only has one wire running through the middle plus some copper shielding outside an insulator. Googling “video low signal” and “video high signal” hasn’t helped. I found a “pin out” but it didn’t help me figure out what kind of cable to connect to the video out.So how can I connect the camera’s output to a video device? Preferably conserving and displaying the full range of image data?

author: Jwillis
author_rank: Super Contributor
timestamp: November 25, 2019, 05:41:39 am
content: It's an automotive connector. Looks like a P69-A1 .http://www.autolumination.com/wiring-electrical-connectors/automotive-engine-chassis-sockets-wiring-connectors-harnesses-plugs/automotive-connectors-6pin.htmMETRI-PACK SERIES 6 Way F Metri Pack 150.2https://www.reynoldsonline.com/ASSETS/DOCUMENTS/ITEMS/EN/12033769_Spec.pdfaccording to the pinout diagram .Can be found herehttps://www.mouser.ca/ProductDetail/Aptiv-formerly-Delphi/12162210-B?qs=sGAEpiMZZMs7eK6h2EBtKqTQL01CPIKsdr0F%252BFfl9LA%3D

author: jhpadjustable
author_rank: Frequent Contributor
timestamp: November 25, 2019, 07:15:57 am
content: It's balanced. I'd start by putting a decently large cap (start with 100nF) in series with the green wire, then connect that and ground to an RCA connector.
What LED diode type needed to fix?? - Page 1
Forum section: electronics / beginners

author: Serge125
author_rank: Regular Contributor
timestamp: November 25, 2022, 10:32:45 pm
content: Hi all!!Ok trying to fix a Christmas light house that has 2 5mm cool white led diodes and one is dead so how can I determine what type of led that I need to replace it, there isn't any markings on the led to know what you need. I know they are both 5mm and I just replaced them with leds that I had but they don't light up and they were both working before I installed them so how can I find the right led to replace the one that is burnt??? There is a very little circuit board that has a cap and resistor, the power input is 12v ac (that powers the spinning motor and yes it's AC) and supply the voltage to the circuit board that has a 47uf 25v cap and a 390 ohms resistor that powers the leds. Thanks for any information regarding this little problem!!UPDATE; Ok did some measurements with my meter on both leds (the one org and the one that I'm replacing) and on the org one the diode test I get no V reading but it lights up (of course) the one I'm replacing I get a reading of 1.8v AND lights up too but it's not white it's a yellowish/green colour. So right there I know that these are two different diode type so what is what so that I can get a replacement?THANKS in ADVANCE!!!!Serge

author: 807
author_rank: Frequent Contributor
timestamp: November 26, 2022, 05:45:34 pm
content: Are you sure your replacement LED is a white one? White LED's generally drop more voltage across them (around 3.4v I believe) than coloured ones.As there is no rectification, the LED's might be connected in inverse parallel, so each one lights up alternately on the direction of the ac.Could you follow the wiring of the circuit in order to draw it out?

author: Swake
author_rank: Frequent Contributor
timestamp: November 27, 2022, 11:26:29 pm
content: Your meter (I assume it is a multimeter) is likely to output about 2V in the diode check mode. That is enough to faintly light up a white or blue LED, but as the LED needs about 3 volts the meter cannot measure it. The multimeter will be able to measure a red, yellow, orange or green LED as these only require about 1.8V.LEDs have a polarity. As explained by 807 and based on your description, the 2 LEDs are likely wired in inverse-parallel. Also this is something you have to consider when testing the LED with the multimeter. The LED should light up in one way but will not light up when the test leads of the meter are reversed.You can replace a broken white LED by another white LED or a blue one. About any 5mm white or blue LED will do. It is likely that the originals are high intensity LED's. Due to the voltage difference it is generally not possible to replace a white LED by a yellow, orange or red LED unless the resistor is adapted to reduce the voltage over the LED.
What length PCB rivets do I need for 1.6mm PCBs?  - Page 1
Forum section: electronics / beginners

author: peps1
author_rank: Regular Contributor
timestamp: May 12, 2022, 01:52:08 pm
content: Have a project where I need to have some solder tags riveted to a board and planing to use M2.5 or M3 rivets, but was wondering how long I need the rivets to be so they swage nice and tight crimping the tag and make contact with the peds?

author: jpanhalt
author_rank: Super Contributor
timestamp: May 12, 2022, 04:10:31 pm
content: According to this:https://www.circuitmedic.com/parts/eyelets.html0.020" to 0.035"(0.9mm) longer than board thickness. Getting a nice flare can be difficult, so I would err on the shorter. I have always soldered when electrical contact was essential.EDIT: Just noticed "solder tags". Be sure to use total thickness in the calculation, not just board thickness. Those are also quite large rivets compared to ones I have used for circuit repair. That would make me biased for something a little larger than 0.020" (0.5mm).
what LPF circuit to use for FM MPX decoder IC output - Page 1
Forum section: electronics / beginners

author: Deactivated-1
author_rank: Frequent Contributor
timestamp: January 11, 2022, 12:21:53 pm
content: so I'm fixing a radio that isnt broken (trying to improve it),and I pointed my attention to the LPF of the FM Multiplex decoder IC (which is a KA2263), and since I did a dumb thing and just removed it entirely, I dont know what it was,the datasheet says I need to also filter out 18khz... why?and if so, can't I somehow mix in a 18khz signal from the IC instead? in the opposite phase?

author: bob91343
author_rank: Super Contributor
timestamp: January 11, 2022, 06:05:32 pm
content: You need a diagram and parts list.

author: jonpaul
author_rank: Super Contributor
timestamp: January 12, 2022, 11:12:00 am
content: 18 kHz LPF removes 38 kHz sidebands of FM stereo composite signal.These are common parts from Murata, TDK, etc.Search"18kHz FM streo filter"j
What makes a 105C capacitor different from an 85C capacitor? - Page 1
Forum section: electronics / beginners

author: Razor512
author_rank: Regular Contributor
timestamp: April 28, 2014, 09:28:17 am
content: I had a chance to take apart an 85C rated capacitor (was planning to do another photo shoot, but I literally could not see a difference between the 85c and 105c capxon capacitors)Do these temperature ratings come from some kind of binning process, or do they add some tears of a unicorn to the 85C caps to make them 105C?105C capxon's that I took apart a while back:http://imgur.com/a/di5y8

author: SeanB
author_rank: Super Contributor
timestamp: April 28, 2014, 09:55:38 am
content: Mostly the electrolyte used and the composition of the seals used to hold it.

author: Razor512
author_rank: Regular Contributor
timestamp: April 28, 2014, 10:07:02 am
content: From what I noticed, both had the same type of seal, and for the liquid it was the same black looking liquid (did not taste it to see if it was any different)Why don't they just add a small insulator around the leads, and just have the entire case welded shut so nothing escapes?

author: Dago
author_rank: Frequent Contributor
timestamp: April 28, 2014, 10:26:53 am
content: Quote from: Razor512 on April 28, 2014, 10:07:02 amHow would you weld something that contains a liquid? It's called a steam bomb.

author: SeanB
author_rank: Super Contributor
timestamp: April 28, 2014, 10:28:01 am
content: Formula of the electrolytes are different, and the seals are different in stiffness and in resistance to long term exposure to the electrolyte. You can make a welded seal, but then the cost per capacitor goes up by at least 3 orders of magnitude. Aerospace rated capacitors which are soldered or electron welded cost a lot more than the same value rubber sealed electrolytic. There you can easily have a cost of $500 or more per capacitor in bulk, as opposed to 5c each for the common electrolytic.
What makes LVDTs (linear variable differential transformer) so expensive? - Page 1
Forum section: electronics / beginners

author: e100
author_rank: Frequent Contributor
timestamp: May 24, 2021, 11:48:39 am
content: Is the price a reflection of the complexity and cost of materials, or is a case of "it's what people are prepared to pay"?Would building my own from scratch work out cheaper or would it be a lost cause?The context is floating level sensor that freely moves up and down and uses a LVDT to measure the vertical position to a resolution of 1mm in 100mm.

author: Ground_Loop
author_rank: Frequent Contributor
timestamp: May 24, 2021, 12:09:17 pm
content: The only ones I've used were micrometer adjusted, high precision, military grade units. So, insanely expensive.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: May 24, 2021, 12:49:25 pm
content: My guess is quantity and paper trail. They're widely used in aerospace.Have you considered a potentiometer instead? 1/100 isn't very accurate, a pot would do. Or a dielectric level sensor, give or take if the fluid has consistent composition.Tim

author: pqass
author_rank: Super Contributor
timestamp: May 24, 2021, 01:25:51 pm
content: LVDTs should be pretty easy to make. It's just three coils of wire on a bobbin!The driving and sensor circuits would be harder but even that isn't anything unusual that a few opamps can't solve.http://www.mikesflightdeck.com/lvdts/lvdts.htmlorhttps://hackscape.wordpress.com/2009/11/27/mclvdt/or

author: e100
author_rank: Frequent Contributor
timestamp: May 24, 2021, 02:35:05 pm
content: Quote from: T3sl4co1l on May 24, 2021, 12:49:25 pmThis is for an outdoor application so LVDTs seem attractive as they don't need weather seals and are immune to the effects of moisture condensation.I spent many hours trying to make an accurate capacitive sensor but I found that water likes to creep and stick to the sides of materials. The books show the liquid surface as being flat but that is far from the truth at the mm scale. Perhaps it's possible in lab conditions with clean water and fancy hydrophobic coatings but in the real world measurements are laggy and inconsistent.

author: janoc
author_rank: Super Contributor
timestamp: May 24, 2021, 03:39:29 pm
content: Sealed ultrasonic transducer bouncing the "ping" off the surface of the liquid (or, if the liquid is churning too much, place a floating lid on top of it and bounce off it)? Those are fairly common and work well, plus there are zero moving parts there (no floats, etc.)See e.g. this paper showing a nice technique (~120um resolution) for ultrasonic ranging:http://www.kurosawa.ip.titech.ac.jp/publications/papers/ast09sh-2.pdf

author: aandrew
author_rank: Frequent Contributor
timestamp: May 24, 2021, 07:01:59 pm
content: A friend of mine did some interesting homebrew LVDT work:http://ruemohr.org/~ircjunk/tutorials/elex/ldvc/lvdc.html(edit: this is his LVDC (capacitor sensor) work, which he did after his LVDT work when he discovered the capacitive sensors are even simpler)
What material should I use for the backing on my breadboard? - Page 1
Forum section: electronics / beginners

author: primegaps
author_rank: Contributor
timestamp: March 29, 2017, 07:06:45 am
content: Hello!I'm starting to get into electronics, and I have just received 3 breadboards that I will begin to mess around with.I saw a breadboard for sale similar to the one in the picture, and I liked the idea of it.I have quite a few power supplies at home, so I would like to be able to plug into my breadboard setup directly with banana cables, just like the picture. I have three 830 tie point breadboards, and I would like to mount them all onto a common backing and secure on some of my own banana connectors to emulate the board i show in the picture.What would be the best material to serve as the backing for such an application?I first considered delrin because I love the feel of it in other applications, but I'm reading now maybe it is not the best thing for me to use. Please let me know if you have any suggestions for me!Thank you.

author: tpowell1830
author_rank: Frequent Contributor
timestamp: March 29, 2017, 07:49:55 am
content: This falls into the category of subjectivity. It will really come down to what you prefer and how much do you want to spend. The idea of aluminum is good, between 4.5 to 6 mm thickness and get it anodized or alodyned to knock down the conductivity factor. Delrin is a good choice as well, what is the reason that you think it is not? You could even use plywood or MDF and if you want to be fancy get a butcher block that is glued together in a checkerboard pattern. Staying along the line of plastic, acetal. You could even use steel, but recommend that you epoxy paint it to alleviate conductivity.Keep in mind the structural characteristics, i.e. wood needs to be thicker than other materials and metal can be thinner. Wood is an insulator and metal is a conductor, treat them as such.

author: crazyguy
author_rank: Regular Contributor
timestamp: March 29, 2017, 08:56:55 am
content: I use Acrylic Sheet for backing

author: Ian.M
author_rank: Super Contributor
timestamp: March 29, 2017, 09:29:57 am
content: A metal backing provides screening, but a wood backing is convenient for temporary mounting of brackets to support controls, speakers, displays or other chassis-mount components.Don't worry about the conductivity of a metal backing - just cover it with Fablon for added insulation. If you do go metal (or stick copper foil on plastic or wood), one terminal, marked 'Ground' should connect direct to it, and ideally, you should provide extra connection points to it just off the edge of the breadboard at either end of each bus strip so that you can get a better ground connection to it, but unless you use copper foil (or PCB) that you can solder individual wire sockets (salvaged from a turned pin DIL socket), into, that can be difficult to do.
What meter is this? - Page 1
Forum section: electronics / beginners

author: tony3d
author_rank: Frequent Contributor
timestamp: October 30, 2013, 11:59:45 pm
content: Does anyone know anything about this meter?http://www.circuitspecialists.com/dm620.htmlWho makes it? Is it any good? Any reviews you know of?

author: Yago
author_rank: Frequent Contributor
timestamp: October 31, 2013, 12:05:28 am
content: On that page it says :"Manufactured in Korea by SMTECH"Not sure if that's just the "bleeding obvious" as Basil would say .

author: Lightages
author_rank: Unknown
timestamp: October 31, 2013, 12:41:51 am
content: This meter has been discussed a bit on the forums here and if I remember the general consensus was that it is not worth buying.

author: fluxcapacitor
author_rank: Frequent Contributor
timestamp: October 31, 2013, 12:48:38 am
content: afaik its made by unisource .http://www.unisource21.com/main.html

author: fluxcapacitor
author_rank: Frequent Contributor
timestamp: October 31, 2013, 01:08:42 am
content: Quote from: Lightages on October 31, 2013, 12:41:51 amhttps://www.eevblog.com/forum/chat/has-anyone-ever-seen-this-dmm/msg158368/#msg158368

author: Stonent
author_rank: Super Contributor
timestamp: October 31, 2013, 10:58:17 am
content: Quote from: Yago on October 31, 2013, 12:05:28 amJust don't mention the war!
What model is this transformer - Page 1
Forum section: electronics / beginners

author: wesley9946
author_rank: Newbie
timestamp: August 18, 2017, 01:54:40 pm
content: Hi everyone,I'm trying to repair a Sony ADP-200ER PSU for a PS4, and it might be that this transformer has gone bad.However, i can't find any info about it.Can anyone tell me what model this transformer is?

author: Zero999
author_rank: Super Contributor
timestamp: August 18, 2017, 02:12:29 pm
content: Have you tried Googling some of the numbers written on it?If that doesn't work, then it'll be a custom wound for the power supply. The core and bobbin will most likely be standard but the windings will be bespoke.What makes you believe it's the transformer? It's probably the last thing I'd suspect.

author: drussell
author_rank: Super Contributor
timestamp: August 18, 2017, 03:53:46 pm
content: It says L1 beside it. It is a choke (inductor), not a transformer