hybridfree/eevblog-posts huggingface dataset:
Reference designator E - Page 1
Forum section: electronics / beginners

author: Aggressive_Doughnut
author_rank: Contributor
timestamp: March 21, 2019, 05:51:04 pm
content: As if the HP custom markings weren't annoying enough (salvaged parts from a printer), I have a board with a handful of parts that look like inductors or capacitors in 1210 size that are marked E - there's even a couple arrays of E parts in 0603 next to a C-marked capacitor array. Has anyone seen these before and knows what they are?

author: Wilksey
author_rank: Super Contributor
timestamp: March 21, 2019, 06:08:15 pm
content: E is normally some notation for Resistor.Usually you see like 200E which means 200R

author: Aggressive_Doughnut
author_rank: Contributor
timestamp: March 21, 2019, 07:30:51 pm
content: I've seen E used for resistance but I don't think that's it in this case. Attached is an image of a section of the board containing parts with reference designators R (resistor), C (capacitor), and E (no idea). There are plenty of L (inductors) as well, but it's hard to get them all in one shot. Sicne there are R, C, and L, designators, it seems like E is meant to be something else, even though it looks to me like an inductor or capacitor. Also since this is the beginner forum, I'lllink in the wiki for standard deisgnatorsfor readers who might not have seen it yet.

author: floobydust
author_rank: Super Contributor
timestamp: March 21, 2019, 08:01:48 pm
content: Those are ferrite chip beads for EMI, considered different than an inductor in the circuit's overall picture. So I see them get a different reference designator, not "L"

author: Aggressive_Doughnut
author_rank: Contributor
timestamp: March 21, 2019, 08:40:45 pm
content: This explains why I don't get sensical readings from RLC measurements...

author: Wilksey
author_rank: Super Contributor
timestamp: March 21, 2019, 10:34:24 pm
content: Ah, sorry, it is clearer with that picture, they are EMI suppression ferrites.
Reference Material and Books - Page 1
Forum section: electronics / beginners

author: danadak
author_rank: Super Contributor
timestamp: February 07, 2017, 11:59:40 am
content: If you want to build your library take a look at this -ftp://ftp.analog.com/pub/cftl/Technical%20Book%20List.pdfRegards, Dana.

author: Vtile
author_rank: Super Contributor
timestamp: February 07, 2017, 03:43:17 pm
content: Quote from: danadak on February 07, 2017, 11:59:40 amOh, so many. I only have seen like a three of those.
Reference voltage of single supply A-to-D converters - Page 1
Forum section: electronics / beginners

author: SolarSunrise
author_rank: Regular Contributor
timestamp: March 08, 2014, 06:36:22 pm
content: There's this very useful chip called ADS1299 which has 8 24 bit fully differential channel with a speed of 16ksps. I've worked with few ADC chips before but this chip is the first that I have seen that has 4.5v internal reference. Aren't the reference voltages usually 2.5v in a 5v single power supply? Maybe I've misinterpreted the data sheet but if it really has 4.5v internal reference, why? Isn't it more inefficient then having 2.5v as reference?Datasheet:http://www.ti.com/lit/ds/symlink/ads1299.pdfThanks as always guys! I'm learning a lot from this forum right now

author: Nerull
author_rank: Frequent Contributor
timestamp: March 08, 2014, 07:09:27 pm
content: The ADCs I've seen use Vref as the top of the scale, either from 0V to Vref or -Vref to +Vref. I don't think I've ever seen one with a Vref in the middle of the scale.

author: uwezi
author_rank: Unknown
timestamp: March 08, 2014, 07:24:10 pm
content: I would say that 4.5 V is a rather unusual reference voltage, but this has nothing to do whether it is efficient or inefficient.This ADC is particularly designed for biomedical applications and I assume that in these fields the traditional signal level suits a 4.5 V reference voltage. This is possibly the range of the output signals which used to be fed into multi-track chart recorders..

author: SolarSunrise
author_rank: Regular Contributor
timestamp: March 08, 2014, 07:59:20 pm
content: Quote from: uwezi on March 08, 2014, 07:24:10 pmIt could be inefficient because if the reference is 4.5v, the input voltage range could only be 0.5v above the reference before getting saturated. However, if the reference voltage is 2.5v, the input voltage is much wider: 2.5v above reference before getting saturated.I just don't understand why the reference is so high. Is there a standard for these kind of devices? Hmm...EDIT:I just checked out the data sheet for ADS1298 (ADC specifically for EKG) and found out TI used 4v reference for a 5v power supply. Looks like these medical devices use very high references...

author: uwezi
author_rank: Unknown
timestamp: March 08, 2014, 08:12:55 pm
content: Quote from: SolarSunrise on March 08, 2014, 07:59:20 pmThe reference voltage normally defines the maximum input signal for the ADC. So the input signal should not be above the reference voltage anyway...
refill solder pot - Page 1
Forum section: electronics / beginners

author: sportflyer04
author_rank: Newbie
timestamp: September 11, 2020, 07:45:41 pm
content: I made a very small "solder pot" by attaching a 1/2 inch Hex shank socket drive to a 60W soldering iron. It's for tinning 12 ga multistrand silicone insulated wire.( The type used between Lipo batteries and the connector). I used 60/40 solder to fill the small pot just to try out the device . It seems to work fine . Now I want to use 63/37 solder instead. I have removed most of the solder but there is some remaining in the pot at the bottom. Will it be OK if I just fill up the remaining with 63/37 solder? Tks

author: Ian.M
author_rank: Super Contributor
timestamp: September 11, 2020, 08:13:21 pm
content: Probably. It depends on how much of a perfectionist you are and how close to true eutectic composition you need it to be. The composition could be corrected with a small quantity of tin or a high tin alloy, e.g bismuth-free Pb-free solder, *IF* you knew fairly accurately how much 60/40 alloy remains.

author: bob91343
author_rank: Super Contributor
timestamp: September 11, 2020, 09:54:06 pm
content: I think any reasonable calculation will show that the difference is virtually unmeasurable. The difference is 3% but the 'contamination' alloy is such a small part of the total it probably will make the resultant closer than its original tolerance. How close is 63/37 to the actual allloy composition? What is the standard deviation?

author: sportflyer04
author_rank: Newbie
timestamp: September 11, 2020, 10:57:22 pm
content: I am not a perfectionist so I will just not worry about and refill with 63/37 solder . TksBTW are there any serious differences between the various solder bars on sale for example from Rotor Metal , Alpha , Kester , and others for my purpose ? I just need the basic. I am leary because last week I purchased a small roll of 63/37 rosin solder from an unknown brand on Ebay and it turned out to be awful.... it wont even stick to resistor leads . I returned the roll.

author: bob91343
author_rank: Super Contributor
timestamp: September 12, 2020, 01:50:27 am
content: I had a similar problem with solder from China. The solder itself is okay but the flux isn't. I got a refund and got to keep the solder. I have a very old tin of soldering paste that works with that solder. In any case, I have better stuff.

author: sportflyer04
author_rank: Newbie
timestamp: September 12, 2020, 04:04:55 am
content: Since the solder bars have no resin in them, I think it should be fine between manufacturers .Maybe the difference whether one has more dross than the other. For my needs a little more dross is no big deal.

author: maginnovision
author_rank: Super Contributor
timestamp: September 12, 2020, 04:21:55 am
content: For our wave soldering machines we usually used alpha bars. Dross needs to be removed periodically anyway, use a dross reducing powder. It allows you to keep the useable solder and pull out everything else(use a steel spoon with holes in it if you really want to keep solder loss to a minimum).
Reflow oven controller - Page 1
Forum section: electronics / beginners

author: dande
author_rank: Contributor
timestamp: October 05, 2014, 08:43:39 pm
content: Hi There!I put together a simple USB based reflow oven controller. I am interested on your thoughts on the design, if there is any flaw in it. I am pretty newbie, so there might be. It uses a ATMega328P as the main controller and a FT232 for the USB connection. A MAX31855 is used to convert the thermocouple voltage levels to usable ones, it will also use a electromechanical relay to turn the oven on and off.I am not quite sure if the FT232 3.3V out's 50mA is enough to drive the MAX31855, or if I should use a dedicated voltage regulator. Also unsure if the USB connection needs protection fuse and/or a ferrite.Thanks all!

author: bobcat
author_rank: Regular Contributor
timestamp: October 05, 2014, 09:26:30 pm
content: The basic circuit looks OK.The USB should be able to power this just fine if you use a solid state relay. I suggest that you use a solid state relay for the oven control. A mechanical relay will eventually fail because it will be switching a lot.Filtering and ESD protection is a must on USB powered devices.Don't forget to add hysteresis to the temperature programming!

author: dande
author_rank: Contributor
timestamp: October 05, 2014, 10:00:20 pm
content: Hey, thanks!So using a fuse on the V+ line is enough protection?

author: bobcat
author_rank: Regular Contributor
timestamp: October 06, 2014, 12:17:34 am
content: A fuse not really necessary. ESD protection and some filtering is more important.

author: dande
author_rank: Contributor
timestamp: October 07, 2014, 08:35:56 pm
content: Okay, I just realised something terrible. Since, the max31855 is 0-3.3V, I need to convert the voltage levels between it and the atmega chip, especially regarding the clock signal which goes from 0-5V from the atmega.I believe the max31855 high output of 3.3V is understood by the atmega as high.

author: bobcat
author_rank: Regular Contributor
timestamp: October 07, 2014, 11:58:24 pm
content: You can operate the ATMEGA328 at 3.3v if you use a 10 Mhz or less oscillator.10 Mhz should be plenty fast enough for this application.
Reflow oven for BGA - Page 1
Forum section: electronics / beginners

author: honeycomb0
author_rank: Newbie
timestamp: December 19, 2015, 02:05:35 pm
content: Hi there!I want to be able to solder LGA ofthat sort of sizeor at least QFNlike this. I would be more than happy to achieve the yield of 25%. Could this be done with DIY reflow oven? Maybe some of you have experience with similar challenges in the past?Thank you all!

author: matkar
author_rank: Regular Contributor
timestamp: December 19, 2015, 04:46:04 pm
content: That's really not a BGA. BGAs have a much narrower pitch. The pitch of the shown component is 1,27mm. The success mostly falls under how accurately you can apply solder paste (stencil) and then place the component.If that is done correctly, I see no trouble with oven soldering.

author: honeycomb0
author_rank: Newbie
timestamp: December 19, 2015, 04:56:45 pm
content: Thanks for reply! Oops, that obv suppose to be LGA!

author: tggzzz
author_rank: Super Contributor
timestamp: December 19, 2015, 05:31:30 pm
content: One issue with leadless components is there might be thermal stress setup between the component and the PCB. It might work initially but fail when the PCB is flexed or thermally cycled.If you have access to a reflow oven, just try it. If you don't, then you can do low-cost experiements using the "skillet method". There are many examples on the web, my experiences are athttps://entertaininghacks.wordpress.com/tag/smd/

author: jmegar324
author_rank: Contributor
timestamp: December 22, 2015, 08:56:44 am
content: Go for it a lot of this stuff can be done with cheap equipment as long as you have persistence.You will develop the skills over time so practice a lot.
Reflow oven for dual sided boards? - Page 1
Forum section: electronics / beginners

author: joeyjoejoe
author_rank: Frequent Contributor
timestamp: June 01, 2019, 05:12:16 pm
content: So I've seen a whack of videos on hacking up an oven to be a reflow oven.How would someone do a two sided board? The 1st side is easy since the bottom side will lie flat.What do commercial ovens do? Do they hold a panel on the edges for the second side so the first is untouched? Does something like this exist in the hobbyist space?

author: mvs
author_rank: Frequent Contributor
timestamp: June 01, 2019, 05:34:44 pm
content: Commercial PCB panels usually have edge rails. They are used to hold and transport panel during whole assembly process.
Reflow Oven - No soak time zone - Page 1
Forum section: electronics / beginners

author: HafizuddinGhazali
author_rank: Newbie
timestamp: November 11, 2017, 10:31:31 am
content: Hello,I'm doing an engineering study about reflow oven duration time, the problem is that my reflow oven does not have the "soak zone time", it goes from the preheat to the reflow zone without going to the soak zone (temperature increase slowly to reach reflow temp). So do i have to set the profile duration of the reflow oven to include the soak zone (duration 180 second) from pre-heat to reflow zone or just duration from pre-heat zone to the reflow zone without soak zone (60 seconds).Sorry for my bad english. I hope you can give me some tips. Thank you very much.

author: Psi
author_rank: Super Contributor
timestamp: November 11, 2017, 10:49:41 am
content: For hobby use and for small production runs at home most people don't worry about a reflow profiles.The toaster oven is simply set to ~190-210C (usually using a DMM thermocouple) and the PCB is placed inside for 3-4 min.So to answer your question no, you don't need to worry about setting a profile.That said, exactly following the manufacture's reflow profile is the correct way to do it, it's just that most people dont bother and have zero issues.

author: Kjelt
author_rank: Super Contributor
timestamp: November 11, 2017, 10:51:17 am
content: Buy a cheap thermocouple datalogger and show (post picture on the forum) what the current profile of your oven looks like.If you want to conduct a study you need it anyway.

author: HafizuddinGhazali
author_rank: Newbie
timestamp: November 11, 2017, 10:59:56 am
content: The thing is I will use this oven for my final year project of bachelor, so I thought that probably critical for me to know the parameter. Thanks brother.The model of the oven is LPKF ProtoFlow Shttps://www.lpkfusa.com/products/pcb_prototyping/smt_assembling/protoflow_s/.

author: Psi
author_rank: Super Contributor
timestamp: November 17, 2017, 10:43:03 am
content: Yes. If its for a academic project you want to do right.

author: hermit
author_rank: Frequent Contributor
timestamp: November 17, 2017, 07:13:49 pm
content: Always do something as close to spec as possible unless you have good reason not to. Unless your project is to test the specs then I'd say do what you can to follow them. Now, if this means a lot of time, effort and money you don't have, then take the advice of those that say strict adherence has been shown to be unnecessary.
Reflow oven - T962 vs QS-5100  - Page 1
Forum section: electronics / beginners

author: Tantalum
author_rank: Regular Contributor
timestamp: June 06, 2019, 04:21:20 pm
content: HalloWell, the question is in the title.I have read that the T962 wasn't that good, especially in the configuration out of the box.On the other hand, there is a topic and youtube video which states that the QS-5100 is far better and doesn't need any modification to make it work well.What's your opinion?Thank you
Reflow oven - Page 1
Forum section: electronics / beginners

author: jgalak
author_rank: Regular Contributor
timestamp: November 30, 2017, 04:19:01 am
content: I've been thinking about a DIY reflow oven, and found the guide here:http://whizoo.com/reflowovenwhich seems incredibly elaborate. So I'm wondering - is all the insulation and sealing really necessary? Can one just retrofit a toaster oven with a temperature controller and call it a day?I was thinking that the Inkbird ITC-310T-B ?controller would be very easy to set up to do this (or any of several other similair ones).The goal would be to create small prototyping boards, probably nothing over a few square inches.

author: hamster_nz
author_rank: Super Contributor
timestamp: November 30, 2017, 04:29:05 am
content: I just use a SSR in an extension cord, and a thermocouple through the side of a door.Completly unmodified small toaster oven, was US$25.Works fine with my 99mm x 99mm boards. Controller doesn't use 'real PID', just tracks profile. All I have to do is open the door when cooked.

author: jmelson
author_rank: Super Contributor
timestamp: November 30, 2017, 04:30:17 am
content: Quote from: jgalak on November 30, 2017, 04:19:01 amI use a GE toaster oven from Wal Mart. it was selected because it was the biggest inside! it has 4 heating rods, two above and two below the rack, running side to side. I patched in an eBay ramp and soak temperature controller. I also got a spool of tiny thermocouple wire. The first board got fried with the thermocouple sensing the air. I then got the idea of poking the thermocouple into a PTH on the board, and it works like a charm.I have done boards up to 8 x 11" in it, but usually do several boards about 3" square at one time.I have done well over 1000 boards with this system.I did not add any insulation to the oven, just used it as is, except for the temp controller.Jon

author: floobydust
author_rank: Super Contributor
timestamp: November 30, 2017, 04:54:33 am
content: OsPIDopen source PID and Reflow oven controller uses Arduino and works OK for me.
Reflow Process Recommendations for rework of Lead Free QFN on Alum-backed PCB - Page 1
Forum section: electronics / beginners

author: pieterhk
author_rank: Newbie
timestamp: April 05, 2023, 05:04:35 pm
content: I work in a ASIC repair center where we use hotplates to manually reflow QFNs on aluminum PCBs with a hotplate preheater, high-activity flux and physically reseating chips. Quite fast for a skilled technician but still not ideal. On hotplate we use 260C to get the lead-free solder flowing easily, works very well if total contact time is short, our ChipQuick flux is very temp stable compared to a large variety of Amtech fluxes we’ve tried.We're looking into use of reflow ovens, we’ve ran a series of tests using a T962 with the ES-Technical mod to get custom profiles and convection for even heating on our large PCBs.We use the same flux (NC191) in the reflow oven and bump up the temps to make sure we get complete reflow. The flux is not working very well, seems to evaporate/burn (quite extreme temps to get lead-free reflowing, 280C peak) but contact must be lost to the soldered data pins as PCB’s are coming out with cracked solder. Our profile is 0.8C/s ramp, 180C soak, 280C reflow and 3C/s ramp down.With hotplate soldering the QFNs don't reflow unless we apply physical pressure on the center of the chips, each QFN has 10 data pins on two sides and Vin/out pads on the bottom, I suspect the reflow is causing the power pads to reflow drawing the solder in together and slightly lifting the whole QFN breaking the digital pin connections. Perhaps heavy use of solder paste may be needed to get a proper reflow.We’ve tried a little with lower temps but don't have the exact specs on the reflow temps required for this manufacturer’s lead-free solder. It becomes soft at 240C and very low viscosity at 260C, we hit higher temps on hotplate reflow for brief periods to make fast work possible and to overcome the bulk heat capacity of the large aluminum PCB and the heavy voltage rails.Totally new to reflow, any suggestions for profiles and fluxes that can handle the extreme temps and stay in contact with all the no-lead pins? Are there any reflow fluxes or perhaps heavy oil-based fluxes that could keep a consistent contact with the whole PCB as it runs through the profile?
Reflowing fine-pitch connectors (HDMI) - Page 1
Forum section: electronics / beginners

author: hamster_nz
author_rank: Super Contributor
timestamp: August 06, 2014, 09:50:03 pm
content: I'm having a 50% hit rate with reflowing HDMI connectors, of the two board I built last night. I've got two problems.1. The PCB is thinner that the legs on the connector, so it can lift up from the board if there is anything behind it.2. To get around problem #1 I'm using Kapton tape to hold it in place, but it tends to pull the connector off center, causing lots of bridges.Anybody got any suggestions that will improve my hit-rate with the current PCB? Or should I just order more thicker PCBs, with slightly smaller drill holes?Is it worthwhile to solder the the connector's legs into place using the before reflowing? I worry though that during the reflow the solder will melt, and the connector will lift, so it won't work.

author: brabus
author_rank: Frequent Contributor
timestamp: August 06, 2014, 11:09:17 pm
content: Is glue a viable way? Just a small dot could do the job, even manually applied.

author: RobertHolcombe
author_rank: Frequent Contributor
timestamp: August 07, 2014, 02:41:16 am
content: I would think that soldering the body of the connector would be the best option, since it will allow you to correctly align the connector and theoretically the SMD connections will reach reflow before the larger thermal mass of the body

author: hamster_nz
author_rank: Super Contributor
timestamp: August 07, 2014, 02:44:01 am
content: Quote from: RobertHolcombe on August 07, 2014, 02:41:16 amI'll give it a try and report back....

author: amyk
author_rank: Super Contributor
timestamp: August 07, 2014, 02:55:46 am
content: How thin of a PCB did you use...? If they're thin enough that soldering is an issue I would certainly consider making them thicker.

author: RobertHolcombe
author_rank: Frequent Contributor
timestamp: August 07, 2014, 04:05:49 am
content: Also you could try suspending the board so that the end with the hdmi connector is floating in free air rather than resting on a surface, avoiding the need for tape

author: hamster_nz
author_rank: Super Contributor
timestamp: August 07, 2014, 04:14:32 am
content: Quote from: amyk on August 07, 2014, 02:55:46 amThe board is 1.2 mm - and it is a little tricky balancing the HDMI connector off to the side, but I'll also give that a try.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: August 07, 2014, 11:08:09 am
content: Datasheet for the connector?Tim

author: Precipice
author_rank: Frequent Contributor
timestamp: August 07, 2014, 11:42:42 am
content: Can you just trim the connector pins a bit shorter, to solve this particular problem?If there's room for things to be slopping around, I'd say your holes were too big - (or are you using holes where the datasheet calls for slots?)Can you get a version of the connector that has plastic location pegs?
Reflowing my first BGA: Tips needed - Page 1
Forum section: electronics / beginners

author: lawrence11
author_rank: Frequent Contributor
timestamp: September 17, 2019, 03:02:35 pm
content: So I have my controleo3 all ready, its been "learned" and received high grade, the profile program has been tested.I am reflowing on 1 chip ATM due to them being the only leadfree BGA of the gang, a 216 bga .8mm with no balls in the middle.Should I risk aligning manually? Or should I contatc somebody with an xray to help? Is manually best I can good enough?Should I put some flux on the pcb copper pads of the bga?This my fluxhttps://www.amazon.com/Solder-Welding-Electronic-Soldering-Lead-free/dp/B076M49M63/ref=sr_1_47?keywords=solder+flux&qid=1568731253&s=gateway&sr=8-47

author: mayor
author_rank: Regular Contributor
timestamp: September 18, 2019, 08:41:49 am
content: When I did my first (and only!) BGA replacement, I watched as many Louis Rossmann videos on the subject as I could. Check it out, you might pick up a tip or two.
Refrigerating solder paste  - Page 1
Forum section: electronics / beginners

author: jgalak
author_rank: Regular Contributor
timestamp: December 18, 2017, 02:53:53 pm
content: I am going to try reflow soldering for the first time (with a hot air station). Just a few components on a small board. I got a syringe of solder paste, stuck it in the fridge, as recommended.Question: how long ahead of time should it be taken out of the fridge? If it requires many hours, and since I'm hoping to work on this in the morning, is it OK to take it out the night before? Or is it just an hour or two?I expect to use only a tiny part of the tube for this project, so want to maximize the usable life of the rest.

author: nicalitz
author_rank: Regular Contributor
timestamp: December 18, 2017, 04:55:07 pm
content: It differs between pastes. From my experience, as a guideline, solder paste usually lasts up to about 6 months when properly refrigerated, and 2-3 weeks when stored at room temperature. Shelf life is therefore reduced by a factor of 10 when storing at room temperature.I syringe should take roughly 3-4 hours to get up to room temperature. An few extra hours at room temperature won't do that much harm. I'm not sure how often you plan on using it, but based on your post I'd guess not too often? If so, the paste will likely expire long before you've used the entire syringe, so I wouldn't be too worried about the temperature.Just be careful not to expose the paste to high temperatures ('high' differs from one paste to the next, but usually >30degC or thereabout), which will damage the product.
Reg PCB replace with mosfet?  - Page 1
Forum section: electronics / beginners

author: harps
author_rank: Regular Contributor
timestamp: December 03, 2017, 07:45:53 am
content: helloi bought a pcb that is meant for an lm317t regulator. (the PCB schematic picture is attached)I hope to put an IRFZ34 n-channel mosfet in its place for 48v (pic of mosfet attached)the 3 pins of the mosfet match up with the footprint so that is good.I wonder do i need to include the two diodes in the schematic and what values would r1 and c2 be ?thank you for any help.

author: Ian.M
author_rank: Super Contributor
timestamp: December 03, 2017, 08:19:22 am
content: A MOSFET + a few resistors is *NOT* a regulator - it can be used as part of a regulator circuit but without other semiconductors it will NOT stabilise the output voltage.There are regulators with a higher input voltage than an ordinary LM317, e.g the LM317HV which is rated for up to 60V input. However in that circuit it will blow at switch on if the transformer output voltage exceeds 42V RMS, and as there is only 12V headroom between 60V and the desired 48V out, and the LM317HV will drop out at a bit under 3V, that means you've only got 9V headroom for ripple, transformer regulation and tolerances and mains voltage variations. That isn't anywhere near enough for reliable operation.

author: rob77
author_rank: Super Contributor
timestamp: December 03, 2017, 08:19:50 am
content: you simply can't replace a linear regulator with a mosfet.it's like replacing a transmission box in a car with a single plain shaft and still expecting it to shift gears

author: Ian.M
author_rank: Super Contributor
timestamp: December 03, 2017, 08:23:44 am
content: Not even that good - its more like bolting a boat propeller to the crankshaft and expecting it to push you along the road!

author: harps
author_rank: Regular Contributor
timestamp: December 03, 2017, 08:44:28 am
content: darn i was looking at the wrong pdf. got the parts mixed up from another project.I have the part here it is a tl783c to be put in the PCB.it has the same pin footprint pin order as an LM317.
Regarding BBCode to edit Posts, Reference? - Page 1
Forum section: electronics / beginners

author: Markus2801A
author_rank: Regular Contributor
timestamp: April 19, 2019, 10:27:02 am
content: HelloWhich type of BBCode is used on this forum? Maybe anybody can give a reference of the syntax and the possible customization options would be nice to create better looking posts. As far as I figured out, its missing some advanced functionality which is available on higher versions of BBCode.Kind regards!Markus from Austria
Regarding capacitor charging and discharging - Page 1
Forum section: electronics / beginners

author: ArjunSukumar
author_rank: Contributor
timestamp: October 09, 2015, 10:10:15 am
content: Hi guys,I want to charge a capacitor using a howland current source ,10V supply and input voltage of 1V

author: matseng
author_rank: Frequent Contributor
timestamp: October 09, 2015, 10:14:42 am
content: That's good that you want that.And me? I want to be 30 years younger, rich and handsomer :-)

author: Paul Price
author_rank: Super Contributor
timestamp: October 09, 2015, 10:37:48 am
content: You have my permission, go for it!If it is Ok with howland, it is Ok with me.

author: crispy_tofu
author_rank: Super Contributor
timestamp: October 09, 2015, 10:48:15 am
content: You can do it!Don't let your dreams be dreams.(Is this what Lightages was talking about - vague questions?)

author: Maxlor
author_rank: Frequent Contributor
timestamp: October 09, 2015, 11:22:43 am
content: Quote from: crispy_tofu on October 09, 2015, 10:48:15 amNo, since there is no question
Regarding Flux and IPA - Page 1
Forum section: electronics / beginners

author: Dokroma
author_rank: Contributor
timestamp: July 09, 2020, 01:13:13 pm
content: Hi, how do you apply flux from a tub? I have rosin core flux, do I use something like a toothpick to coat the pins before soldering? Also, how do you then clean it off? Do you use isopropyl? Do you just get a Q tip and wipe down the board with the IPA?

author: jmelson
author_rank: Super Contributor
timestamp: July 09, 2020, 04:29:30 pm
content: Quote from: Dokroma on July 09, 2020, 01:13:13 pmIf you want to clean it, use water soluble (WS) flux. SO much easier to clean off. Otherwise, IsoPropyl or denatured (ethyl) work, if you scrub with a toothbrush.Instead of a toothpick, I use a bit of solid-core wire, dip in flux and wipe on pins.Jon

author: mayor
author_rank: Regular Contributor
timestamp: July 10, 2020, 10:07:27 am
content: Quote from: jmelson on July 09, 2020, 04:29:30 pmIsn't water-soluble flux quite corrosive? ie, ensure a really thorough clean if you use.

author: ceoxrad
author_rank: Regular Contributor
timestamp: July 10, 2020, 11:32:40 am
content: Quote from: mayor on July 10, 2020, 10:07:27 amIt is, and cleaning with DI water and a suitable detergent is mandatory, for hobby use I think is quite a pain actually. better to stick to rosin (RMA, or RA if you work on tough boards) and then clean with IPA or a commercial flux cleaner.Acetone can also be used, but only in special cases and with utmost care (can dissolve component legends and some plastics, cheap solder mask can be attached too!)

author: jmelson
author_rank: Super Contributor
timestamp: July 10, 2020, 01:30:51 pm
content: Quote from: ceoxrad on July 10, 2020, 11:32:40 amI'm using SRA water-soluble flux I buy on eBay. You get a flux pen (sort of like a fiber marker, but bigger) and a refill bottle.Just a couple seconds in running water has the board absolutely spotlessly clean. I scrub for a few seconds with a toothbrush just to make sure.Jon

author: KL27x
author_rank: Super Contributor
timestamp: July 10, 2020, 09:45:35 pm
content: The paste rosin flux in a tub is more useful for dipping the ends of largish wires in there. Pretty much all it's good for. For board/component level soldering, liquid flux is more convenient. Apply to the board, generally, not the components.
Regarding Semtech SX1272RF1 LoRa Communication Range issue - Page 1
Forum section: electronics / beginners

author: Unknown
author_rank: Unknown
timestamp: July 28, 2016, 06:24:23 am
content: HiI am trying to build a LoRa network using raspberryPi1 and Semtech SX1272RF1 LoRa modulehttp://au.rs-online.com/web/p/radio-frequency-development-kits/9225873/.I used the basic example fromhttps://www.cooking-hacks.com/documentation/tutorials/extreme-range-lora-sx1272-module-shield-arduino-raspberry-pi-intel-galileo/I read that LoRa supports extreme range ,but I am not able to communicate over a long distance at least in a line of sight.I am getting a very low range of 1m.What I am missing.

author: Pjoudislav
author_rank: Newbie
timestamp: July 29, 2016, 01:45:36 pm
content: What antenna do you use?Odesláno z mého Nexus 5X pomocí Tapatalk

author: Unknown
author_rank: Unknown
timestamp: July 30, 2016, 08:10:08 am
content: 868MHz .Its obtained with the development kit

author: ebclr
author_rank: Super Contributor
timestamp: September 23, 2016, 01:44:59 am
content: If you like to save some money40 USDhttp://www.mouser.com/Search/ProductDetail.aspx?R=P-NUCLEO-LRWAN1virtualkey51120000virtualkey511-P-NUCLEO-LRWAN1
Register FLUKE Onetouch Series II - Page 1
Forum section: electronics / beginners

author: kdl1950
author_rank: Contributor
timestamp: August 07, 2022, 08:16:28 am
content: Hello everyone,I have a Fluke Networks OneTouch Series II.Unfortunately, when I turn it on, the register message bothers me.I contacted Fluke and was told that the network division had been sold to NetScout.There I was given the following information:"Hello Alex,The Fluke OneTouch PRO Series II was retired some time ago, before NetAlly became a company and acquired the handheld tools and AirMagnet software from NetScout. Unfortunately we cannot offer support for that device. If you are interested in our current products, you can read further here: Handheld Network Testers | Network Performance Analyzer | NetAllyThank you kindly,NetAlly Technical Support"Now my question is whether someone can help me to register the product or permanently delete or suppress the message?Thanks in advance.Regards
Regulable linear power supply with discrete components and short circuit protect - Page 1
Forum section: electronics / beginners

author: timofonic
author_rank: Frequent Contributor
timestamp: February 21, 2015, 04:31:31 pm
content: Hello.I'm a novice electronics student and need a regulable lineal power supply. I used the search function of the forum and was unable to find a similar question to mine.- I have virtually unlimited supply of discrete components from the lab.- I have very limited access to ICs, but I may buy stuff like LM317 is they are cheap to buy and can make the design easier.- Despite of all that, I have a very limited budged to buy stuff.Are there some schematic to do? Preferable to not need to make my own PCB.Regards.

author: rdl
author_rank: Super Contributor
timestamp: February 21, 2015, 08:23:40 pm
content: The LM317 is cheap and it's just about guaranteed to work, though it does have some limitations. You should get some. Then find and download the data sheets. There are several and some have many more example circuits than others. Watch Dave's first power supply (#221) video. He went over how the LM317 operates in some detail before deciding to go with a different, more expensive regulator.

author: tautech
author_rank: Super Contributor
timestamp: February 21, 2015, 08:46:07 pm
content: One of the adjustable linear regulator IC's is your best bet IMO. 317,337 etcNearly all of their datasheets have a simple PSU circuit.Easy to implement, reliable, inbuilt thermal and short circuit protection as well as fold-back current limiting.Their main drawback is dissapation, but if you limit your design to say 15 V that will reduce it lots.Spend good money on a Bournes 10 turn pot, you won't regret it.Good output terminals also make a PSU a pleasure to use, see if you can find some with 4mm cross drilled holes as well as suitable for 4mm banana leads.Speaker cabinet types usually are good grunty types.As for forum searches use the Search button close to the Home button for all searches.
regular USB and USB micro pinout on PCB? - Page 1
Forum section: electronics / beginners

author: prebs
author_rank: Newbie
timestamp: August 21, 2013, 12:33:42 pm
content: Can anyone confirm that the pinout is correct on this pcb that I am making. Can't really find much documentation on what the standard pinout for these two usbs are. Anyone know ?Thanks

author: bbarbour
author_rank: Contributor
timestamp: August 21, 2013, 12:42:34 pm
content: When I'm finalizing my design, I pick a final part and use the datasheet to create and/or verify the design. I've found that connectors in general are a friggin nightmare sometimes. It's not like ICs where pin layouts are at least mostly predictable no matter what vendor/chip. Until I'm at the point where I'm crossing my "T"'s and dotting my "i"'s, I'm not usually concerned about the exact specifics on the layout (just as long as my current template is at least the right dimensions).

author: rexxar
author_rank: Frequent Contributor
timestamp: August 21, 2013, 12:52:33 pm
content: It depends on the specific connector you get. You can get USB connectors in any orientation at all, so your pinouts could be backwards for half the USB connectors out there. Like bbarbour said, pick a final part, and look at its datasheet.

author: prebs
author_rank: Newbie
timestamp: August 21, 2013, 01:48:02 pm
content: But as long as the data sheet confirms what pins are 1,2,3 and 4 ... then I should be fairly safe right? Because a lot of the data sheets i've been looking at, for a number of connectors, only show pins not "vcc, gnd, d+ and d-".

author: G7PSK
author_rank: Super Contributor
timestamp: August 21, 2013, 05:19:23 pm
content: http://en.wikipedia.org/wiki/USBIts all here.

author: bbarbour
author_rank: Contributor
timestamp: August 21, 2013, 05:47:05 pm
content: Most of the time, the PCB pins/pads should roughly correspond to the receptacle's configuration (sometimes they are staggered on the board for dense layouts and the staggering method is up to the manufacturer). For simple connectors like USB, I'd go out on a limb and say yes, PCB pins 1, 2, 3, 4 should correspond to the USB standard.

author: Smokey
author_rank: Super Contributor
timestamp: August 22, 2013, 12:06:41 am
content: One good resource for making sure you get land patterns correct is look at a layout and pinout for some open source PCB. I usually go check out some Sparkfun breakout board or something.

author: westfw
author_rank: Super Contributor
timestamp: August 22, 2013, 07:02:22 am
content: Most of the USB-B (device) full-sized connectors I've seen use a 2x2 layout for the pins.

author: metalphreak
author_rank: Frequent Contributor
timestamp: August 22, 2013, 12:44:15 pm
content: It looks like you have the layout for the connector on the left, which is probably not what you want?
Regulated 5V/1A (min.) USB power supply? - Page 1
Forum section: electronics / beginners

author: BigBrother
author_rank: Regular Contributor
timestamp: August 01, 2012, 09:51:48 am
content: it seems like every power supply I see doesn't have a rating or it's a dodgy chinese one. my Raspberry Pi came in on Monday but I'm now waiting on cables and I'm still bumming around for a proper power supply for it. Adafruit's regulated one is out for another couple of weeks and newark's has a lead time warning of 137 days. there's another on sparkfun but I'd need an adapter cable to use it. any ideas? I'm in Texas, USA. budget: 8$/ea, I need 2.

author: caroper
author_rank: Regular Contributor
timestamp: August 01, 2012, 09:58:36 am
content: I just use a cellular phone adapter/charger.I have used adapters from both HTC and LG with no problems and any cellphone charger with a micro USB output should work and be easy to find, often discarded.CheersChris

author: PA0PBZ
author_rank: Super Contributor
timestamp: August 01, 2012, 10:01:26 am
content: Exactly, most phones and tablets come with these today. Since mostly you only need one there is always one to use for more interesting things

author: BigBrother
author_rank: Regular Contributor
timestamp: August 02, 2012, 08:01:09 am
content: Quote from: T4P on August 01, 2012, 11:40:01 amI ordered 2. One to use then smash and the other to mess with... then maybe smash.

author: BigBrother
author_rank: Regular Contributor
timestamp: August 03, 2012, 03:37:43 am
content: Quote from: Electroalek on August 02, 2012, 01:18:48 pmI probably will at some point. for now, I managed to find a wall adapter for a belkin 7-port USB hub! 5V/3.5A! I'll be getting a USB connector from an old case in a minute and hacking off some other bits for use with it as well!

author: BigBrother
author_rank: Regular Contributor
timestamp: August 03, 2012, 05:50:01 am
content: wooh! it works! it's a bit dodgy though, I have the usb's black wire openly soldered to the barrel connector's outside and voltage drops from unloaded 5.17V to loaded 4.85V which is fairly close to non-working voltage. I think I'll shrinkwrap it or just tape it.
Regulations for placing stickers on the PCB - Page 1
Forum section: electronics / beginners

author: Sruk
author_rank: Contributor
timestamp: February 14, 2017, 08:58:04 am
content: Greets!I'd like to make myself a rule for placing plastic stickers on the PCB. By those I mean serial number or quality check self-adhesive stickers.To do that, I would like to make a custom board space for the stickers to be added on.Is there any kind of regulation (IPC/JEDEC) or maybesuggestion how to provide such space on the PCB properly.Please check the file attached.Any kind of help will be welcome, thx!Sruk

author: tron9000
author_rank: Frequent Contributor
timestamp: February 14, 2017, 09:25:00 am
content: I'm not aware of any. I just got some back from the placers and they stuck their batch numbers anywhere they could.

author: AndyC_772
author_rank: Super Contributor
timestamp: February 14, 2017, 09:31:11 am
content: Count yourself lucky that your boards have space on them not occupied by components.

author: Zero999
author_rank: Super Contributor
timestamp: February 14, 2017, 09:33:36 am
content: The only time I could see this being a problem is where hazardous voltages are concerned, as the label adhesive might not be an adequate insulator to be covered by the regulations.Functionality wise it might also be a problem with high impedance, high frequency circuits for the same reason stated above.Just keep the sticker clear of anything mentioned above.

author: tron9000
author_rank: Frequent Contributor
timestamp: February 15, 2017, 09:11:24 am
content: Quote from: Hero999 on February 14, 2017, 09:33:36 amyeh wouldn't do having a sticker on a 5Gohm resistor!

author: Neilm
author_rank: Super Contributor
timestamp: February 15, 2017, 07:18:42 pm
content: Quote from: tron9000 on February 15, 2017, 09:11:24 amIt does not have to be over a resistor. I have had problems with them stuck over creepage slots or by 100M resistors. With 10kV over it the adhesive started to conduct and changed the apparent value of the resistor by over 2%.At work we have standard sticker size for serial numbers and have a box marked in the solder mask for the serial numbers (one for surface mount, one for through hole and one for RoHS if the PCB isn't marked)
Regulator Bypass - Is this okay? - Page 1
Forum section: electronics / beginners

author: ssashton
author_rank: Frequent Contributor
timestamp: May 10, 2022, 03:08:42 pm
content: Hi,I have a board with anXL7015switching regulator on the input to produce +15V. However for the most part I expect to already provide +15V to the board; I'm adding the reg to future proof the design in case I feed a higher voltage.Is the regulator going to be okay if I disable it by pulling 'EN' pin HIGH and then bypass the input to the output?Additionally, am I going to need a current limiting resistor to pull EN HIGH, say 10k, or is it reasonable to just attach directly to the main supply?Thanks!

author: ledtester
author_rank: Super Contributor
timestamp: May 10, 2022, 03:30:49 pm
content: Not sure about your question, but in your schematic your R6 doesn't look like it's placed correctly if you're copying the datasheet's circuit. It should go between GND and FB not GND and the output.

author: ssashton
author_rank: Frequent Contributor
timestamp: May 10, 2022, 03:49:29 pm
content: Oops thanks for that!

author: tlovie
author_rank: Contributor
timestamp: May 22, 2022, 12:31:31 am
content: The datasheet seems to indicate that the absolute maximum ratings for EN Pin voltage are -0.3 to 7 V, and the typical value for the OFF threshold is 1.6V. It sounds like you would need to set up a voltage divider to pull the pin to the correct level, or you may damage the device. Small inconvenience, or just tie that enable pin to ground and move your enable jumper to the VCC/Vin of the XL7015.
Regulator question - Page 1
Forum section: electronics / beginners

author: neo
author_rank: Super Contributor
timestamp: September 30, 2016, 06:43:41 am
content: This may be a question, aka why its here, but why does my regulator have 5 pins?http://datasheet.octopart.com/LM2941-National-Semiconductor-datasheet-118224.pdfi plan to use it regulate between 10 and 20v right at an amp

author: Kleinstein
author_rank: Super Contributor
timestamp: September 30, 2016, 06:56:49 am
content: Some regulators use more pins for extra functions compared to the minimal 3 pin configuration for a regulator. The lm2951 happens to have 5 pins used - same cases have even additional unused ones.Usually it is not a good idea to use such regulator close to there maximum current. The drop out is not that small anymore and heat dissipation gets a problem. The SOA may not even allow for a large drop at full current. So one should look for a larger one, maybe rated for 1.5 or even 3 A. However with additional features like shutdown the choice is not that large.If it is 20 V in and 10 V out, there is no need for a low drop regulator. Its than usually better to use a conventional one like 7810 / LM317.

author: neo
author_rank: Super Contributor
timestamp: September 30, 2016, 06:59:14 am
content: what i have is a set of iv-6 vacuum fluorescent displays a ~27v supply and a want to use an adjustable regulator to adjust the voltage between 10 and 20v, the reason i have this specific one is i have them in my parts binre-reading the iv-6 datasheet and it wont be quite that high half that at most

author: neo
author_rank: Super Contributor
timestamp: September 30, 2016, 07:05:10 am
content: i suppose my question was more or less, what do i do with/about the on off pin

author: Ian.M
author_rank: Super Contributor
timestamp: September 30, 2016, 08:20:50 am
content: Bring it out to a 2 pin header with ground and put a jumper on it for now to hold the regulator on. Remove jumper, connect logic output and you can then switch the power to the VFDs on demand. If you decide to put a pullup there to 27V like the datasheet shows, put it on a 3rd header pin! If you use a mechanical switch, you can connect it to both the pullup and ON/OFF, but it avoids the logic getting 27V stuffed up its chuff which it wont like much.
Reinforcing cable insulation? - Page 1
Forum section: electronics / beginners

author: elroy
author_rank: Regular Contributor
timestamp: September 04, 2020, 10:51:55 pm
content: I have a 5-year-old power supply for a MacBook. The computer end of the cable terminates in a connector that magnetically attaches to the laptop. A couple of cm down from this end, the cable's insulation has gotten worn away. There's about a 1 cm length where the metallic shield inside the insulation is visible. The shield and wiring isn't broken, though, so the power supply is working fine.I'd like to reinforce the frayed area to keep the power supply usable as long as possible. A few wraps of electrical tape are one obvious approach. Any better way to approach this? Heat shrink unfortunately isn't usable because the magnetic connector is too large to allow heat shrink of appropriate diameter to pass over it. The other end of the cable is not detachable from the psu enclosure.

author: GreyArea
author_rank: Contributor
timestamp: September 04, 2020, 11:03:32 pm
content: Maybe roll some Sugru around it? It's wonderful stuff.

author: Ian.M
author_rank: Super Contributor
timestamp: September 04, 2020, 11:13:41 pm
content: Self amalgamating tape, preferably the silicone rubber type not the butyl rubber type.

author: elroy
author_rank: Regular Contributor
timestamp: September 05, 2020, 01:49:37 am
content: Quote from: Ian.M on September 04, 2020, 11:13:41 pmThat's a hoot, searched for this and found a listing for XFasten tape featuring a picture of someone wrapping it around the power supply cable for a MacBook in exactly the same place.

author: mzzj
author_rank: Super Contributor
timestamp: September 05, 2020, 07:11:16 pm
content: 3M super 33+