hybridfree/eevblog-posts huggingface dataset:
Soldering pads on LED strips together - best soldering tip size and style? - Page 1
Forum section: electronics / projects

author: victorhooi
author_rank: Regular Contributor
timestamp: September 17, 2024, 02:31:57 am
content: Hi,I need to solder several addressable LED strips together, and I'm having trouble getting a consistent and perfect join.The pads are roughly 1mm wide.I'm using a chisel tip at the moment, which is 1.8mm x 0.8mm (link to tip), and to be honest, it is a bit of a pain, and my results are patchy (some of this is likely me - I'm a bit rusty here) and I'm worried about bridging between the Data and GND lines:Is there a different style and size of soldering tip that people would suggest for this application?Also, for the jig, I'm using aSolder M8- however, these are COB strips, and there's a white protrusion which makes means the teeth don't really grip properly, and the strips keep slipping.Thanks,Victor

author: victorhooi
author_rank: Regular Contributor
timestamp: September 17, 2024, 02:37:01 am
content: Also, forgot to mention - the solder is I'm using is SN100C, and I've set the iron to 370 C.

author: Someone
author_rank: Super Contributor
timestamp: September 17, 2024, 04:20:05 am
content: Only solder? no wire?

author: victorhooi
author_rank: Regular Contributor
timestamp: September 17, 2024, 04:28:28 am
content: Yeah, this is for joining two pieces of LED strip together.I line up the pads, apply flux, and flow solder across the pads.In other cases (e.g. at ends, or for power injections), I would solder wires onto the pads.

author: Someone
author_rank: Super Contributor
timestamp: September 17, 2024, 04:55:47 am
content: Join them with wire, even if adjacent/touching/close. Solder should only be a thin fillet.

author: DaJMasta
author_rank: Super Contributor
timestamp: September 17, 2024, 06:48:13 am
content: Why is your solder 100% tin? Are you using flux?

author: Phil1977
author_rank: Frequent Contributor
timestamp: September 17, 2024, 08:18:30 am
content: Regarding that you just build solder bridges your skills seem to be quite good! Especially with SN100, which I personally have no good experiences with.As already mentioned: If you just use a little piece of wire for each joint it will be much easier. Maybe you could also just use some kind of pin header between the LED strips, though it would probably cause a few mm of distance.

author: ArdWar
author_rank: Frequent Contributor
timestamp: September 17, 2024, 09:38:01 am
content: This style of joining is fine if the two PCB are rigidly connected relative to each other, with no vibration, flex/bending and differential expansion expected. For example between two PCB within a rigid case, each mounted with fixed screws near the joinOtherwise a short wire to relieve the forces acting on the pad should be *much* more reliable.
Soldering complex footprint problems (without paste) - Page 1
Forum section: electronics / projects

author: nuclearcat
author_rank: Unknown
timestamp: August 28, 2020, 07:50:10 pm
content: Is it even possible to solder such SIP without stencil?I tried several times, and in most of cases one of SWD pads (and seems many others) was not connected well. Got SWD once, but then flashing didnt worked (seems elsewhere no soldering joint, maybe on VCC).(small side pads are 0.4mm x 0.5mm)This is vendor recommended footprintSIP in question is named WM-SG-SM-42 (LoRa module, STM32L052 + RF frontend).P.S. I think for manual assembly (as i dont have precise paste dispenser) better to put via in pads?Cause i am afraid solder blobs on them lifting up whole package.

author: thm_w
author_rank: Super Contributor
timestamp: August 28, 2020, 10:08:09 pm
content: So it comes as shown in the photo? With some solder bumps on the pads already.Its possible, but I don't know which method is best. With BGA's it seems best to: flux, put a thin layer of solder on the pads, clean, reflux, then place BGA. Of course it has to be relatively even height, maybe its harder with those odd shaped pads. Are you sure the full device is getting hot enough to reflow as well? Leaded solder will be easier.OwO has posted some photos, but this is no reballing so too much solder for what you are trying to do:https://www.eevblog.com/forum/fpga/cyclone-5-recovered-from-scrap-boards/msg3106784/#msg3106784

author: nuclearcat
author_rank: Unknown
timestamp: August 29, 2020, 06:47:22 am
content: Quote from: thm_w on August 28, 2020, 10:08:09 pmYes, lead free solder (damn it). I have oven, but profile is not for lead-free.Also seems this large pads are culprit. It is very interesting that OwO in that thread applied pressure, it might be good substitute of adding vias in each pad.
SOLDERING REWORK STATION HOT AIR GUN - Page 1
Forum section: electronics / projects

author: Long Technical
author_rank: Newbie
timestamp: May 02, 2018, 12:58:21 pm
content: https://youtu.be/EHQVsxZkT8kIn this video i had show you Soldering Rework Station Hot Air Gun All of thing we need in there. Please check on description and do step by step you will get Soldering Rework Station Hot Air GunLook at the description at my video you need to download all of thing need to make PCB. You can make at home by yourself but you can use my gerber file and upload toJLCPCB.COMfor make PCB online. I order PCB fromJLCPCB.COMalot of time and i alway get PCB with high quality only 2$ for 10PCB and Big Discount on First order Shipping. Let try it
Soldering Standards? - Page 1
Forum section: electronics / projects

author: elmood
author_rank: Regular Contributor
timestamp: April 29, 2015, 01:44:39 pm
content: Hey folks,I've been making boards for many years and recently used a new PCB assembler. They made me a sample which looks great, and then delivered the first half of my order which has through-hole soldering that makes me cringe. I've attached a picture showing a few views of a board.After some arguing I'm being told that there is nothing wrong with the soldering because it meets IPC Class 2 which only requires 50% fill inside the holes. The balls of solder on some pads apparently is no big deal and I shouldn't worry about it. But I don't want to send my product out looking like this... I would expect better quality if I was the customer.Thoughts? Any arguments I can use to back up my case?

author: tautech
author_rank: Super Contributor
timestamp: April 29, 2015, 03:17:04 pm
content: Welcome to the forum.Check out this thread:https://www.eevblog.com/forum/projects/industrial-soldering-handbook/

author: Tomorokoshi
author_rank: Super Contributor
timestamp: April 29, 2015, 03:39:07 pm
content: I'm looking through IPC 610. My copy is IPC-A-610D from January 2000. I don't seem to have a newer copy around.Look into:5.2.4 Soldering Anomalies - NonwettingFigure 5-37: Defect - Class 1, 2, 3. Solder has not wetted to the land or termination where solder is required. Solder coverage does not meet requirements for the termination type.7.4.5 Unsupported Holes - SolderFigure 7-89: Defect - Class 1, 2, 3. Lead not discernible due to excess solder.One approach:Compare the difference between the sample and the first production article. Explain that with that much variation it will be hard to trust the quality of the continuing production. Ask if they can explain why there are production differences.

author: JuKu
author_rank: Frequent Contributor
timestamp: April 29, 2015, 04:16:17 pm
content: The bottom picture is unacceptable. It looks to me that all solder is on the end of the pin as a ball, very little if any is in the hole.

author: peter.mitchell
author_rank: Super Contributor
timestamp: April 29, 2015, 04:25:38 pm
content: for some of the joints (mainly the large, flat tabs) you have the wrong kind of footprint/plated hole. For these you should use plated slots, these are better mechanically (the board is more uniform to the tab) and they solder correctly with the wave soldering too.

author: elmood
author_rank: Regular Contributor
timestamp: April 29, 2015, 09:43:37 pm
content: Hi Peter,I tend to use holes to prevent additional charges for slots. So far I've used these same parts in tons of boards and never had this issue. The worst part is that they gave me an absolutely great looking sample (hand soldered, not machine soldered thru-hole) and then turned around and sent me what you see in the picture. I'm just trying to make good stuff for my customers... I'm in supplier-wrangling mode at the moment.
Soldering station with Weller WXP120 - Page 1
Forum section: electronics / projects

author: Bikeneer
author_rank: Newbie
timestamp: December 11, 2022, 09:48:20 pm
content: HelloI'am thinking about building DIY soldering station based on Weller's iron WXP120. Until now, I found only few information about soldering tweezers.So few questions to start:Does someone have schematics of the internal board of that iron?As I understood, there should not be any special protocol between station and iron, just I2C directly to chips?Why they use 50 Hz toroidal transformer in their stations? Do they have any special reason for it? Or could it be run simply from 24V= SMPS?Thank you

author: strawberry
author_rank: Super Contributor
timestamp: December 11, 2022, 10:22:18 pm
content: 50Hz transformer less noise. good power factor(smaller transformer).original regulate at zero cross rather than noisy phase angle regulatorsome PID temp control

author: jwet
author_rank: Frequent Contributor
timestamp: December 12, 2022, 12:51:00 am
content: There really aren't any electronics to speak of in the iron- there is a heating element and thermal feedback generally with an RTD. The return cable has a lot of wires- for the mentioned stuff plus a couple of grounds and shields. You can dope it out with a ohm meter and a power supply without too much trouble. There is nothing wrong with running them on DC or PWM, etc. Weller runs them on AC with a Triac because its cheap and works. Weller has good user manuals but you won't find schematics, etc. for irons or controllers from any official source. There is just too much chinese cloning for soldering iron companies to be that open. A bit of digging on google will probably turn up some reverse engineered schematics, etc as these are expensive items and their technical owners are often trying to service them. I have an older German model WDM2 controller with two outputs, one feeds a very fine iron that uses the 3.5 mm plug in tips- pretty good system overall, the second channel feeds a WMRT tweezers which are wonderful. All of this is for fine rework and SMT and is really great. Look at used controller on Ebay or elsewhere- this stuff has little resale value one it falls out of calibration, etc at a big company.

author: Bikeneer
author_rank: Newbie
timestamp: February 06, 2023, 10:08:53 pm
content: Could someone measure diameter and approx length of pins in Weller's WX connector please?I want to find some usable sockets to make connector (station side), but don't have solder pen yet.If you have some hint for suitable sockets, let's share it
Soldering with indium / sources of indium in Europe - Page 1
Forum section: electronics / projects

author: cheater
author_rank: Regular Contributor
timestamp: August 17, 2021, 04:40:04 pm
content: Hi all,I am modifying a cooler and I was wondering if anyone had experience soldering copper to aluminum using pure indium or indium-silver solder In97Ag3. Additionally, I'm looking for a source of indium in Europe.I have been able to deposit a good bond of solder to the heatsink in question using normal Sn60Pb39Cu1 (the Cu is for not dissolving solder tip plating) using AmTech NC-599-v2-TF flux.However, 60/40 will only have a thermal conductivity of 50 W/mK as opposed to 73 W/mK of the Indium-Silver solder or 83 W/mK of pure indium, plus indium and the indium solder melt at 156C and 143C respectively as opposed to 183-190C for normal 60/40. This is important because the heatsink itself has its fins soldered to the base using a solder which I think is at around 200-220C melting point.However, I am not aware of the properties of indium when soldering, and I am curious if anyone has any experience, or can suggest any good fluxes.I want to solder copper sheet metal (roughly 40x20x1.5mm) to a part copper, part aluminum heatsink base (the border between those two happens where I have to put down the sheet metal).I am hoping for a sturdy bond that will withstand some pressure and which will transfer heat well.BTW, I know this will require a lot of power from the soldering iron, I have six very powerful soldering irons available, and if need be I can use them all at once.Regarding buying pure(ish) indium, I've looked around and prices even for bars are anywhere between 2x and 10x market value, which is pretty crazy. Can someone suggest a place I could get indium in Europe at anywhere close to 180 Eur/Kg (in quantity of say 50-250g)?I will need about 3000-5000 mm^3 of indium for my project, and at these prices, I might as well not start my project at all...
Solderless Breadboard Kit with Enclosure and power supply? - Page 1
Forum section: electronics / projects

author: Chris56000
author_rank: Frequent Contributor
timestamp: March 04, 2020, 12:45:43 am
content: Hi!Does anyone know of a reasonably priced breadboard enclosure that can have two, three or four solderless breadboards built into it with provision for terminals, switches, power supply and function generator modules, meter modules, etc., etc., or kits of parts for this?I'm thinking of using it for the labs in the book "Learning The A of E", and the suggested model is way outside of my pocket money!EPE Magazine used to produce designs for these as part of their "Teach–In" series, but they relied upon metalwork or woodworking skills that I'm useless at, or special custom cases/enclosure parts only available for a very short time after the article's publication!Chris Williams

author: exe
author_rank: Unknown
timestamp: March 04, 2020, 11:29:02 am
content: Quote from: Chris56000 on March 04, 2020, 12:45:43 amAn alternative solution could be buying these modules separately from China. Use DMMs instead of meters.

author: kallek
author_rank: Regular Contributor
timestamp: March 05, 2020, 04:43:04 pm
content: Hi! I do not know if there are that kind of units somewhere, but for reasonable quality it will be very expensive and bulky. I think that at least for me, better and much more versatile solution is separate power supply and function generator, and big breadboard with 4mm binding posts on it.If you want that kind of unit, for bread-boarding simple LM317/LM337 or fixed 78xx/79xx regulator solution will suit well and do not take much space. These regulators have built in current limit, but sure it is better to have adjustable current limit. You can also find some simple function generator circuits to build your own module.Kalle

author: GreyWoolfe
author_rank: Unknown
timestamp: March 05, 2020, 08:57:46 pm
content: Here is an Elenco analog/digital trainer from eBay UKhttps://www.ebay.co.uk/itm/ELENCO-MODEL-XK-550-ANALOG-DIGITAL-ELECTRONIC-COURSE-TRAINER-IN-A-HARD-CASE/254154698817?epid=2255472386&hash=item3b2cccf041:g:cJ8AAOSwPEhcgWS4Look at the similar sponsored items below the ad. There might be something that strikes your fancy.There are serious modern units by Global Specialties but the basic unit starts at around $500 USD, not cheap by any means.
Solderless press-fit connectors - Page 1
Forum section: electronics / projects

author: Rachie5272
author_rank: Regular Contributor
timestamp: April 04, 2022, 05:04:48 am
content: Can anyone recommend a supplier for solderless press-fit circuit board connectors? So far the only manufacturer I can find is Mill-Max, but I'm sure there must be others. I'm looking to replace 0.1" headers, and JST-style connectors.

author: tooki
author_rank: Super Contributor
timestamp: April 04, 2022, 04:02:37 pm
content: Würth Redfit is really interesting. I’ve been meaning to try those out.Harwin and Samtec make some.I think you just need to dig a little deeper. They’re out there. I just suspect that due to the markets that use them most (like automotive), they’re not terribly prevalent at retail, but have to be ordered from the manufacturers.
Solenoid firing from 2 x AA batteries. - Page 1
Forum section: electronics / projects

author: SteHughes90
author_rank: Newbie
timestamp: February 20, 2014, 10:39:01 pm
content: Hi all,I'm new here so please go easy. I've got high school level electronics education and about 6 months of playing with an arduino behind me...I've got an idea for a project where I need a small solenoid to fire when I press a micro switch, sounds easy right?Well the project is small and the biggest power source I can fit in would be 3 AA batteries....My thoughts are I could do this with a camera flash circuit where I replace the flash with the solenoid...I charge a capacitor, when I press the micro switch the capacitor discharges through the solenoid giving it the necessary Amps and Volts to move it.Only problem is how the hell do I do this :/Any help would be appreciated

author: NiHaoMike
author_rank: Super Contributor
timestamp: February 21, 2014, 01:52:24 am
content: Could you use a low voltage, high current solenoid? NiMH batteries can supply a lot of current, R/C lithiums even more.

author: mariush
author_rank: Super Contributor
timestamp: February 21, 2014, 02:45:14 am
content: A cheap 12v solenoid needs about 100-400mA to switch. I'm not sure that a capacitor will be small enough and give you enough energy to reliably trigger the solenoid.A very simple solution would be to use a boost dc-dc converter to about 10-12v, or whatever the minimum the solenoid would need to switch.2-3 AA batteries will provide enough current and a good boost converter will do 10-12v from 2.4-4.5v that 2-3 batteries will provide.See for example LT1308 - datasheethere. It can do 300-400mA at 12v from 3-4.5v, less at lower input voltages, and doesn't use much power when it's idling (about 0.1mA).You can find it already soldered on an adapter board on eBay for under $4 :http://www.ebay.com/itm/1PCS-LT1308BCS8-LT1308B-ON-DIP-ADAPTER-/320987115225?pt=LH_DefaultDomain_0&hash=item4abc52aed9and you only pay attention in the datasheet to pick the right inductor and schottky diode and the suitable resistors to get 10-12v out of it and you're in business. The datasheet explains everything well and the circuit examples have recommended parts under them so you can just google them and then buy alternative parts (with similar specifications)Only remark I would have is that if you plan to get the chip with the DIP adapter board, you should solder the input capacitor straight on the adapter board, as close as possible to the voltage and ground pins, for stability.Here's a spice simulation, as you can see it can do about 12v 400mA from as little as 3v. With 4.5v in, you can tweak it to handle more current if the solenoid needs it (but then the AA batteries may not be able to give it that much current).

author: NiHaoMike
author_rank: Super Contributor
timestamp: February 21, 2014, 03:37:07 am
content: Quote from: mariush on February 21, 2014, 02:45:14 amSome good quality NiMH AAs will have no problem supplying a few amps for a short time.
Solenoid power supply - Page 1
Forum section: electronics / projects

author: CoilKid
author_rank: Contributor
timestamp: August 28, 2014, 10:22:24 pm
content: I am building a power supply for a solenoid, and came up with this.I use a CVCC to power this, not a capacitor. That probably can go without saying, but I wanted to say it.I also use anFET, adiode, and aphoto interrupter.So I'm fairly sure this will work, and I've gotten a "Looks good to me" but I'd like to double check.Thisshouldfunction in such a way, that the inductor(solenoid) receives a current of 1A when the photo-interrupter is occluded. When the interrupter is no longer occluded, the inductor(solenoid) will turn off, and will release a voltage spike, which gets dissipated by the freewheeling diode.If someone else can give me the all clear I'll start ordering parts. Otherwise, could you please point out what's wrong?TIA,CoilKid

author: Paul Price
author_rank: Super Contributor
timestamp: August 28, 2014, 11:38:10 pm
content: Just use a transistor instead.

author: CoilKid
author_rank: Contributor
timestamp: August 28, 2014, 11:58:05 pm
content: Assuming I want to use an FET. Would this work?

author: Paul Price
author_rank: Super Contributor
timestamp: August 28, 2014, 11:59:04 pm
content: if you hooked it up just like the NPN transistor and the MOSFET is a N-MOSFET, then yes!

author: CoilKid
author_rank: Contributor
timestamp: August 29, 2014, 12:01:11 am
content: Itisan N-Channel MOSFET, rated for 40V @ 5A. The link to the page was in my OP.

author: CoilKid
author_rank: Contributor
timestamp: August 29, 2014, 08:12:31 pm
content: So, assuming that I use an N-channel MOSFET, could someone look over my schematic, look over the parts I'll be using, and tell if if this should supply 1A current to the inductor when the interrupter is occluded?
soliciting analog opinions - Page 1
Forum section: electronics / projects

author: grouchobyte
author_rank: Regular Contributor
timestamp: August 14, 2016, 05:00:20 am
content: One of my consulting projects, a high current DC to 1 MHz transconductance amplifier with rather stringent functional and performance requirements has me tasked with some redesign of a current product (excuse the double entendre). Multiple current cells (example of basic positive current cell attached below) provide scale-able bipolar current and there are numerous challenges in meeting thermal, compliance, accuracy, linearity and stability needs for a lab metrology-grade instrument.That said, there are some legacy tweaks in the old design that need to be explained ( the documentation and the original designer are not available). My client wants to know if we still need some the questionable circuits that were implemented in the past.T1 is implemented as a board structure of two parallel traces about 6 inches long. I only have a picture so I can only guesstimate the trace width length, spaces and the board material, etc.T1 might have been implemented as an empirical tweak to compensate for some distortion at higher frequencies or to null out or rolloff some instability based on a specific opamp or existing board parasitic. I can do some sims on it but my fear is that won't really explain why its there and whether it is warranted in the newer design/layoutI scratch my headwhen I see T1 virtually "un-terminated" at the opamp inverting node. Does anyone have a better feel for what and why this was done?You can be vague or detailed.....all feedback welcome.Thanks muchosGraciashay-shaytukdankamerci@grouchobyte

author: grouchobyte
author_rank: Regular Contributor
timestamp: August 14, 2016, 05:18:59 am
content: Quote from: evb149 on August 14, 2016, 05:11:27 amGood one EVB149!....and thanks.Yes, R1 is a 100 milliohm current sense resistor with a kelvin connection. Obviously at DC (in steady state mode) there are no issues or concerns and T1's contribution is nil. Its clearly a second board spin tweak to fix something that showed up unexpectedly@grouchobyte

author: grouchobyte
author_rank: Regular Contributor
timestamp: August 14, 2016, 05:30:17 am
content: Surely it couldn't have anything to do with matching the fuse inductance...EDIT: Then again paralleling the tracks will couple them like a transmission line transformer / directional coupler, but it will also minimize the inductive loop area (like a non-twisted pair or microstrip) formed between their common connection point and the OAs node, so if there was magnetic flux it would induce less EMF around the loop due to the close coupling, assuming the final diversion to the opamp input is short.fuse inductance? maybe, but its likely not the lowest hanging fruitHere as a shot of the old board structure( circa 1990):@grouchobyte

author: 2N3055
author_rank: Super Contributor
timestamp: August 14, 2016, 09:25:18 am
content: That looks like a directional coupler in series to sensing resistor... To have different feedback at dc and ac...Probably was tuned to have a specific step response of output current..
Solid Polymer Non-polarized vs Wet Electrolytic for AC (back to back capacitors) - Page 1
Forum section: electronics / projects

author: snoop33
author_rank: Contributor
timestamp: August 31, 2022, 09:38:35 am
content: We all know aluminium electrolytic can be wired back-to-back as the properties allow for a short reverse current pass.What I don't know is whether the properties of solid polymer aluminium capacitors exhibit the same property.Does anyone know?

author: Vovk_Z
author_rank: Super Contributor
timestamp: August 31, 2022, 10:49:20 am
content: Why not?I accidentally used solid polymer caps 6.3 V and 16 V rated in an additional RCLC-filter for filtering +5 and +12 VDC lines of ATX power supply wired in reverse (auxiliary power supply for Asus Essence STX sound card). It worked several weeks until I found a mistake. Caps were just hot (not very hot). Then I reversed them back to normal orientation, and it works fine. (I have checked them - they are ok with capacity and ESR).

author: snoop33
author_rank: Contributor
timestamp: August 31, 2022, 12:37:13 pm
content: I wasn't sure if they still act as a short in reverse and maybe they aren't from what you say, just leaky. Wet aluminium act as a short and build heat until they pop.

author: CaptDon
author_rank: Super Contributor
timestamp: August 31, 2022, 01:28:26 pm
content: Back to back polarized electrolytics as a substitute for a 'real' non-polarized capacitor is a bad idea. Think about what happens in ever changing non-symmetrical waveshapes. The charge voltage across each capacitor will alter according to the reverse current leakage but during the unequal charging phase over the waveshape there will be a certain current and/or voltage distortion introduced including a D.C. offset. It has been argued thousands of times if two back to back polarized are equal to a non-polarized. You know what you will never see used as motor start, motor run or power factor correction in industry or on an electrical pole.....Back to back polarized electrolytics. It is just simply a bad practice. It is rumored some manufacturers actually put two back to back caps in one can and call it non-polarized??? Can't say I have ever cut open an N.P. capacitor from a reputable manufacturer and found any truth to that rumor. YMMV?

author: T3sl4co1l
author_rank: Super Contributor
timestamp: August 31, 2022, 01:57:12 pm
content: I wouldn't recommend it without antiparallel diodes.Despite what ripple current they're rated for, they aren't rated for such high ripple voltage anyway, so, think of it as "motor start cap" applications, not "run". Momentary use, short life.Tim
Solid State Amp Project - Page 1
Forum section: electronics / projects

author: angelothewolf
author_rank: Contributor
timestamp: May 02, 2013, 03:52:11 am
content: Hi there! Im planning to make an small 100W guitar amplifier head, small as possible with 100W of power. i made a few TIP142/147 amps with this PCB. but i wonder what improvements can i do to this circuit, or if there is another way to get 100w from that type of size/complexity amp,,,

author: NiHaoMike
author_rank: Super Contributor
timestamp: May 02, 2013, 04:28:02 am
content: TI makes some chips that will do as much as 600W in a size of a quarter and need only small heatsinks, as long as you're willing to solder surface mount.

author: Tube_Dude
author_rank: Regular Contributor
timestamp: May 03, 2013, 02:55:49 am
content: HiPut a 1K resistor in series with the input electrolytic capacitor and a Zobel network at the output of the amp. Both actions will improve the amplifier stability...Edit: Put a 100K resistor in parallel with the 100 pF capacitor at the input. It will charge the 10uF electrolytic input capacitor, in absence of any source connected to the amp.
Solid state "high current" magnetic switch? - Page 1
Forum section: electronics / projects

author: rea5245
author_rank: Frequent Contributor
timestamp: November 03, 2018, 02:28:58 am
content: Hi,I want to turn a microcontroller-based circuit on and off based on the location of a magnet. My first thought was to use a reed switch, with Vcc coming through the reed. But then I thought, maybe there's a solid state or MEMS alternative. I looked around and found only magnetic sensors, which don't provide the "high current" (not really very high - just 100mA or so) that powering a uC would require. It seems the magnetic sensors are just intended to provide a signal to an IO pin.Is there something smaller and less fragile than a reed switch that can turn power on and off? And what I really want is for the switch to be open in the presence of a magnet, and closed when the magnet goes away.Thanks,Bob

author: filssavi
author_rank: Frequent Contributor
timestamp: November 03, 2018, 02:33:35 am
content: The only solid state alternative I know is a latching circuit (soft power on) with a Hall effect digital sensor as trigger

author: jbb
author_rank: Super Contributor
timestamp: November 03, 2018, 08:45:47 pm
content: Two options come to mind:a Hall Effect sensor and a load switch IC such as theAP2280using a deep sleep mode in the microprocessor (some have a 'shutdown' mode with < 1uA draw) and connecting a Hall Effect sensor to the wakeup pinI would tend to suggest the microprocessor sleep mode because it's smaller and cheaper. Also, you would be able to leave the micro on for a brief period to finish off a task after the magnet is removed.Finally - look out on the Hall Effect sensor. Do you want it to respond to North poles, South poles or either pole of a magnet?

author: T3sl4co1l
author_rank: Super Contributor
timestamp: November 04, 2018, 12:36:33 am
content: Note that Hall effect sensors can be costly in terms of operating current. It may be worthwhile to run the micro periodically (sleeping most of the time) and poll for inputs, turning on the sensor to check.The sensor may take a long time to start up or settle. Check if the datasheet says anything about it, and check around for other parts if they're any better or what.Reed relays aren't terrifically cheap but they are dumb, stand-alone components.Tim

author: calexanian
author_rank: Super Contributor
timestamp: November 04, 2018, 07:32:58 am
content: Yes a reed switch to drive a relay coil.
Solid state relay (Mosfet) form " C " MBB ( make before break ) 10A Min 3-5 Volt - Page 1
Forum section: electronics / projects

author: HCT203
author_rank: Newbie
timestamp: October 25, 2016, 04:39:09 am
content: Seeking designing help for A form " C " solid state switch capable of switching 10 A minimum DC max contact impedance less than 0.005 ohms yes 5 milliohms , max operating voltage 3-5 volts switching time > 0.10sec yes 100 millisecond rep rate less than 1 per 10 second , duration of NC to NO can be as long as fraction of second , most important is there is a short for at least 0.05 second between NC Commom & NO . manufactured target price < $10.00 at OEM quantity ( >1,000)Compensation either as one shoot design charges / royalty over product life , maybe combination of both .size / reliability are top priority after cost .Contact me at aab@tech2000ltd.com for more info .
Solid State Relay High Side DC Switch - Page 1
Forum section: electronics / projects

author: petersanch
author_rank: Regular Contributor
timestamp: January 06, 2019, 05:54:20 am
content: Hi All,The internal circuit of the SSR im using has 2 N channel MOSFETs.Is it possible to make a high side switch with this? Can I connect the load in either configuration as in the pictures and expect the same results?Cheers

author: Zero999
author_rank: Super Contributor
timestamp: January 06, 2019, 09:05:37 am
content: Yes, that will work.Does the polarity of the power supply to the load never change? If it's DC and is never reversed, then only one MOSFET is needed or the two MOSFETS in the package can be connected in parallel. For DC operation, pins 4 and 6 could be connected together and to the positive side, with the load on pin 5.

author: petersanch
author_rank: Regular Contributor
timestamp: January 06, 2019, 09:17:06 am
content: Thanks. The polarity is always the same.So I understand fully, is the reason for connecting the positive side to pin 4 or 6because of the body diode in the MOSFET?If it is the body diode, does that mean for configuration B in the picture, the power supply ground connects to pin5 and the load can connect to 4 and 6?

author: Zero999
author_rank: Super Contributor
timestamp: January 06, 2019, 10:26:02 am
content: Quote from: petersanch on January 06, 2019, 09:17:06 amThe MOSFETs are connected back-to-back so they block current in both directions, when they're off. If the current is only ever applied in one direction, then only one MOSFET is required, although they're are two in this IC, so you might as well connect them in parallel to give a much lower on resistance.To use the two MOSFETs in parallel, connect pins 4 and 6 together. The load can then be either connected between pin5 and 0V, with pins 4 and 6 at +V or between pins 4 and 6 and +V, with pin 5 to 0V.

author: petersanch
author_rank: Regular Contributor
timestamp: January 06, 2019, 10:28:02 am
content: Thanks for explaining

author: Zero999
author_rank: Super Contributor
timestamp: January 06, 2019, 10:31:52 am
content: Here's the modified schematic.
Solid state relay that will turn off when the primary voltage is removed. - Page 1
Forum section: electronics / projects

author: Jim-0000
author_rank: Regular Contributor
timestamp: April 02, 2019, 07:02:21 am
content: I have a small collection of solid state relays. They all trigger the secondary "contact" to conduct when the primary is excited with (in this case) 12 volts.However, they stay on after the primary voltage is disconnected.By "stay on", I mean the secondary terminals remain in the closed condition for some time, many seconds, maybe a minute sometimes.Question:Can some one suggest a solid state relay for low voltage/current, that has the properties where the secondary follows the primary?In other words, the secondary "points" open again, after closing, when the primary actuating voltage is removed or switched off.Jim.

author: Zero999
author_rank: Super Contributor
timestamp: April 02, 2019, 10:01:20 am
content: Yes, it sounds like the original poster is using a TRIAC based SSR on DC, which will only turn off, when the secondary power is disconnected.You need a MOSFET based SSR such as the PVG613.https://docs-emea.rs-online.com/webdocs/140c/0900766b8140cdcb.pdf

author: Jim-0000
author_rank: Regular Contributor
timestamp: April 02, 2019, 08:24:22 pm
content: Thanks for the replies Blueskull and Zero.

author: NiHaoMike
author_rank: Super Contributor
timestamp: April 03, 2019, 01:39:01 am
content: If it helps, SSRs for 12-24V DC are often sold as "3D printer MOSFET modules".

author: Jim-0000
author_rank: Regular Contributor
timestamp: April 13, 2019, 11:16:13 pm
content: It turned out that a simple 4N25 opto coupler did the job that I wanted in this application.https://www.futurlec.com/LED/4N28.shtmlThanks for all the good replies.Jim.

author: Psi
author_rank: Super Contributor
timestamp: April 13, 2019, 11:59:22 pm
content: Quote from: NiHaoMike on April 03, 2019, 01:39:01 amI think those are mosfets with an opto included on the PCB.That's different to an SSR which provides isolation without any requirement to 'power' the module itself.
Solid-state switch for -200V - Page 1
Forum section: electronics / projects

author: LukeW
author_rank: Frequent Contributor
timestamp: September 10, 2021, 08:55:33 am
content: I need to switch a fairly high negative voltage (-200V) from an optically coupled input. The load impedance is high, and a low-current FET such as SSN1N45 will be used.An architecture something like this will be used, with a zener to protect the optocoupler and one to protect the FET gate from excessive Vgs.Any suggestions or constructive feedback would be welcome.

author: Wolfram
author_rank: Frequent Contributor
timestamp: September 10, 2021, 09:52:41 am
content: If you just need to close a MOSFET between your -200 V rail and the output, a MOSFET-output optocoupler would be significantly simpler. These are sometimes also called optoMOS and DC solid state relays, to help the search. You could also use a photovoltaic isolator driving the MOSFET gate directly. How fast does it need to turn on and off?To comment on the original circuit:With the values as they are, there would be very little voltage on the gate. With the optocoupler solidly conducting, R2 and R3 would form a voltage divider, giving 200/34 = 5.9 V on the ZTX857. The combined voltage drop of R4 and the transistor B-E junction would drop just under a volt together, giving an emitter voltage of around 5 V (and a dissipation of 1 W in the transistor). The R6 + R7 divider would further reduce this to around 0.45 volts. It could be made to work if you removed R6 + R7, and increased R5 to limit the dissipation and current draw. It won't be particularly fast, and I probably missed something else important as well in my quick analysis.

author: coromonadalix
author_rank: Super Contributor
timestamp: September 10, 2021, 11:16:03 am
content: I find this circuit over complicatedyou have ssr (solid state relays) who can be easily interfaced ex: an 5vdc input (already isolated from the ssr)you need to switch an 200 volts, and what is the current needed ? protection ?

author: Caliaxy
author_rank: Frequent Contributor
timestamp: September 10, 2021, 12:29:52 pm
content: Quote from: Wolfram on September 10, 2021, 09:52:41 am^^^^ This is important. Also, what’s the nature of your load? Do you need to simply turn it on and off or you need to apply precisely defined pulses?

author: Zero999
author_rank: Super Contributor
timestamp: September 10, 2021, 12:40:16 pm
content: A MOSFET and opto-coupler with a photovoltaic output will do.Suggested opto-couplers: APV1122, TLP3905, VO1263A. The turn-off time can be reduced by adding a circuit to turn rapidly discharge the MOSFET gate capacitaince, when the opto-coupler is turned off.
Solid State Tesla Coil Mains Filter - Page 1
Forum section: electronics / projects

author: Ronny
author_rank: Contributor
timestamp: January 13, 2016, 05:48:34 pm
content: Good afternoon folks,My friends and I are designing a Solid State Tesla Coil, we just begun. But there is a problem, we are afraid that when we first test it, it could make magic smoke come from something else in the mains.We saw multiple filter designs for Spark Gap Tesla Coils. But they are freaking huge, absolutely not intended for the power of our equipment (about 250 W).I saw a discussion that was going on with the Tesla Coil guys. Some of them said that a filter between the mains and the Tesla Coil should be connected in inverted configuration. The explanation they gave is that we are trying to protect the mains from the Tesla Coil, and not the Tesla Coil from the mains. Do you guys agree with it?Also, do you guys think a regular mains filter (used for PCs, Home theaters, etc.) would do the job? Or that we should design and build the filter ourselves?If so, do you guys have any schematic we can begin with?And lastly, do you guys think a little Tesla Coil (about 41 cm tall / 250 W) is powerful enough to cause problems in the mains? Keep in mind that we will display it in a fair in the university, and if we screw up the mains we will destroy other students projects!!!Thank you very much!

author: Fungus
author_rank: Super Contributor
timestamp: January 13, 2016, 06:53:10 pm
content: Mine's a similar size. I run it through a mains isolation transformer and only discharge into the air.No mains filter as such, but I've not had any problems so far (nb. anecdotal evidence, my Tesla Coil probably isn't the same as your Tesla Coil).Discharging into strike targets is another matter. It generates a lot more RF and can cause havok for everything in the area. The only way to do it safely is to have your own grounding cable for the target and take it outside to a big metal stake in the ground. Even better: Don't do it, stick to air discharges. You'll be more popular.

author: MagicSmoker
author_rank: Super Contributor
timestamp: January 13, 2016, 09:25:14 pm
content: Quote from: Ronny on January 13, 2016, 05:48:34 pmDon't agree at all: the primary purpose of a mains filter is, in fact, to protect the mains from any noise that might be produced by the device.A commercially available IEC inlet filter rated for a bit more RMS current than you expect to draw (higher current rating is not better from a noise-filtering perspective) will certainly be helpful here. That said, the noise produced from an arc discharge will far exceed that produced from a resonant switchmode converter (which a "solid state" Tesla coil qualifies as).

author: Fungus
author_rank: Super Contributor
timestamp: January 13, 2016, 10:43:07 pm
content: Quote from: MagicSmoker on January 13, 2016, 09:25:14 pmYes, the primary coil driver is just a fancy switch-mode power supply. It's not really going to make much noise.The RF generated by the sparks will bypass any amount of filtering you can add to the mains side (it's radio!).
solidworks fan and filter models? - Page 1
Forum section: electronics / projects

author: coppercone2
author_rank: Super Contributor
timestamp: September 03, 2018, 08:14:59 pm
content: Are there any high performance fans suitable for electronics use that are quiet, and have good flow (or a balance of therof) with manufacturers solidworks models?I am kind of playing around with solidworks flow but I am not going to try to model a fan. Am I SOL?Also, how about filter meshes? Like say the stainless steel mesh used as a air vent filter and RFI gasket in test equipment. Or a membrane that stops dust. Can you model these as a bunch of holes even though they are actually a bunch of chaotically organized fibers or foam-like material? I don't mean honey-comb (which I can figure out how to model) but the ones that kinda look like brillo pads or something.Edit: Found the porous media. How about fans?If you just measure the CFM of the fan and the pressure drop, can you like make some kind of design choice (maybe some kind of short flow laminizer) at the cost of larger chassis to just use static numbers/surfaces/inlets in the flow simulation?

author: Mr. Scram
author_rank: Super Contributor
timestamp: September 03, 2018, 09:36:32 pm
content: Modelling a fan is the easy part. Simulating it correctly can bring some challenges.

author: coppercone2
author_rank: Super Contributor
timestamp: September 03, 2018, 09:37:42 pm
content: Can you make a design choice to eliminate the need for a fan model and all that turbulant crap and make a surface as an inlet? Like a tunnel?And its not easy you need to make all the curved surfaces and rotating shit and measure it, there is no way I am doing that, its a hassle enough to make the 3d part of altium accurate so it can be put into solidworks.It's not for mass production so I can live with a oversized chassis.Does a ducted fan automatically fulfill these requirements? I would prefer to use ducted fans anyway, then I can make a little HVAC system for the PCB
solidworks flow superfluid simulation? - Page 1
Forum section: electronics / projects

author: coppercone2
author_rank: Super Contributor
timestamp: August 29, 2018, 10:26:28 pm
content: So I rewatched that old 60's video about superfluids and I thought it was rather interesting, with second sound and everything.I don't see anything on google though.

author: Bridiges
author_rank: Newbie
timestamp: August 30, 2018, 02:53:26 am
content: want to know more content in the forum that I come across these new things.
Solution to control magnets - Page 1
Forum section: electronics / projects

author: Remark
author_rank: Contributor
timestamp: January 30, 2022, 09:43:48 pm
content: Hello everyone!There is a need to control the door using a magnet (lock/unlock). At this point, I think the right magnet would be let's say 12VDC, 8W, and the load about 30kg. Can this magnet be controlled using a simple SSR relay? Or do I still need to use a transistor and flyback diode schematic configuration?The type of magnet I would like to use:https://ae01.alicdn.com/kf/HTB1ugk3PFXXXXbTXXXXq6xXFXXXy/8W-DC-12V-30kg-Electromagnet-Electric-Lifting-Magnet-Solenoid-Lift-Holding-ELE-P40-25.jpg_Q90.jpg_.webpOne of the SSR relays:https://universalshowroom.news/pic_1/40801-1-vnt-dc-relais-3-32vdc-5-60vdc-ssr-25aa-solid-state_pics.jpgI read that SSRs are protected against voltage surges. But I would still like to know if that would be the right solution...

author: ledtester
author_rank: Super Contributor
timestamp: January 30, 2022, 10:21:26 pm
content: Check the SSR's datasheet. Not all SSR's are designed for inductive/capacitive loads, e.g.:https://electronics.stackexchange.com/questions/605956/are-ssr-relays-suitable-for-inductive-and-capacitive-loadsAlso see page 3 of this Omron app note "Solid State Relays Common Precautions":https://omronfs.omron.com/en_US/ecb/products/pdf/precautions_ssr.pdfI'd be wary of the "30kg" rating of the solenoid. I've experimented with similar electromagnets and they don't meet their "kg" rating -- at least in the intuitive sense.

author: moffy
author_rank: Super Contributor
timestamp: January 30, 2022, 10:22:36 pm
content: The SSR looks OK, but I would definitely put a freewheel diode across the coil because the inductive switch off spike will have quite a bit of energy, better safe than sorry.

author: mrburnzie
author_rank: Regular Contributor
timestamp: January 31, 2022, 09:17:24 am
content: Next to the diode I would add a snabber and a beafy varistor.

author: SeanB
author_rank: Super Contributor
timestamp: January 31, 2022, 09:30:28 am
content: Yes, supressor diode or MOV, which should be a part rated at 18V for 12V coil. Across the coil, and then you do not need the catch diode if you use the MOV. Those magnetic latches that say 30kg mean with the coil itself energised with 12V, so the feed wiring needs to be rather beefy to apply 12V there, or you need to have 13V or more as supply. They will open if you apply more than 300N force to them, so are not really secure, to hold a door closed you really need a 250kg or 500kg lock, which on 12V typically needs 1A of power to stay locked.For these the easiest is a relay, makes work easier, and 10A 5v coil relays are pretty cheap and reasonably reliable. Will likely last the life of the door as well, and you get a bonus of NC contacts so you only have to energise the relay to release the door.
Solving inductor whine in a HV DC AC inveter for EL panels - Page 1
Forum section: electronics / projects

author: robint91
author_rank: Contributor
timestamp: December 28, 2015, 07:47:33 am
content: I have designed a HV DC AC inverter for EL panels, Which can generate around 200 Vrms 2 kHz AC. But when I use it there is a lot inductor whine coming from the LC filter I guess. My EL panels needs around these voltages/frequencies to decently light up.Does anyone have an idea how to solve it? I have used these inductorshttp://katalog.we-online.com/pbs/datasheet/7687714102.pdfand a good film capacitor.I start of with a supply of 24 Volts and boost that up to around 200 Volt which then goes into a High voltage H-Bridge. The Inverter is driven by a two level pwm generated from the MCU. The PWM switching frequency is around 50 kHz. I have tried to make that higher but it only will heat up the mosfets quite a lot.I need a decent sinewave because I use MOC3063 and Triac to switch the AC else a large dv/dt would retrigger the SSR and I couldn't turn that particular panel off.Thank youRobin
SOM-RK3399 software support if anyone worked  - Page 1
Forum section: electronics / projects

author: LakshmiN
author_rank: Contributor
timestamp: April 19, 2020, 10:03:25 am
content: Hi,Has anyone worked with SOM-RK3399 from the friendly arm?(http://wiki.friendlyarm.com/wiki/index.php/SOM-RK3399)I'm finding difficult to find their support in both Hardware and Software as their forum is least active.

author: LakshmiN
author_rank: Contributor
timestamp: April 19, 2020, 11:55:18 pm
content: Could you please provide me the link to the forum?

author: LakshmiN
author_rank: Contributor
timestamp: April 21, 2020, 02:20:09 am
content: Thank you.