hybridfree/eevblog-posts huggingface dataset:
Seeking suggestions for temperature switches - Page 1
Forum section: electronics / projects

author: Rasterist
author_rank: Contributor
timestamp: November 13, 2020, 11:48:49 pm
content: I have an application where I'd like to turn a fan on and off based on a hardwired temperature. The ideal device would have three pins: Vcc, GND, and output, where output would source up to, say, 200 mA from Vcc when the temperature is above the threshold and floated (or shorted to GND) when below (with some hysteresis to prevent ringing, as in a thermostat). The device can be screwed or glued to a heatsink and costs less than a dollar. A cursory search yields very expensive, stainless steel type things and very inexpensive things that produce a logic signal but can't source what I need (while I could amplify the logic signal with a transistor, that significantly increases the complexity compared to what I'm imagining). I thought I'd turn to the hive mind to try to save some time. Does what I'm looking for exist? Thanks for any pointers.

author: tszaboo
author_rank: Super Contributor
timestamp: November 14, 2020, 12:49:12 am
content: TI has temperature switches. It is not going to switch 200mA, but you can connect the output to a FET, a BJT or a driver.https://www.ti.com/sensors/temperature-sensors/temperature-switches/overview.html

author: Rasterist
author_rank: Contributor
timestamp: November 14, 2020, 03:11:29 am
content: Yeah, those are the cheap ones I was referring to, but, as I said, I'd really like to avoid adding a transistor (or anything), if possible. It seems to me I'm not the only one who could use something like what I described, so I assumed it already existed. Maybe I was wrong.
Seeking rare Teac 4-pin vintage remote connector model - Page 1
Forum section: electronics / projects

author: DavidAlfa
author_rank: Super Contributor
timestamp: November 22, 2022, 11:01:54 pm
content: I've been asked to interface of of these, but this connector is driving me nuts!Does anyone know what model it is? Or if it's propietary?Some models having this connector, but not limited to: X-2000, X-2000R, X-2000M, Z5000, Z6000, Z7000, V-707RX, V-909RX, V-800X, V-900X, R-777X, R-888X, R-999X, V-850X.

author: DavidAlfa
author_rank: Super Contributor
timestamp: November 22, 2022, 11:11:31 pm
content: These look similar, but nowhere to be found else than these pre-made dashcam wireshttps://www.amazon.com/dp/B07FHYQ3Z5
Seeking Validation and Component Requirements for IM73A135 Breakout Board - Page 1
Forum section: electronics / projects

author: destinyawait
author_rank: Newbie
timestamp: April 08, 2024, 04:22:49 am
content: Hello everyone,I'm reaching out for assistance and validation regarding a breakout board schematic I've created for the IM73A135. As a newcomer to PCB design, this marks my first attempt at creating a schematic and PCB layout.I've meticulously followed the datasheet to ensure accuracy, but given my lack of experience, I'm uncertain if the schematic will function seamlessly with an ESP32 development board as intended.My primary concern is determining if the schematic will function optimally with just the MEMS microphone alone, without the need for additional components like amplifiers, OpAmps, codecs, DSP, or a 24-bit ADC.I've compiled the schematic into a PDF file, which I'm eager to share for review. If there are any components I've overlooked or incorrectly added, I would greatly appreciate your guidance and expertise.Your feedback on the schematic's functionality and any additional component requirements would be invaluable to me as I navigate this learning journey in PCB design.Thank you in advance for your assistance and support.IM73A135 Datasheet:https://www.infineon.com/dgdl/Infineon-IM73A135-DataSheet-v01_00-EN.pdf?fileId=8ac78c8c7f2a768a017fadec36b84500

author: destinyawait
author_rank: Newbie
timestamp: April 08, 2024, 11:05:13 am
content: After reviewing several articles and gathering additional information, I have made updates to the schematic. Your valuable insights and feedback would greatly contribute to finalizing the schematic.

author: destinyawait
author_rank: Newbie
timestamp: April 08, 2024, 02:51:58 pm
content: I have made adjustments to the schematic. Could someone please review it and provide assistance if needed?
Seeley / Breezeair Control Protocol? - Page 1
Forum section: electronics / projects

author: ludzinc
author_rank: Unknown
timestamp: June 14, 2017, 01:39:22 pm
content: Hi AllLooking for some help. I'd like to integrate my home AC control into an Automated Home network, and to do this I plan to attempt to decode the protocol the controller uses.First step was to open a unit and share some pics.<iframe width="480" height="360" src="http://s803.photobucket.com/user/ludzinc/embed/Eevstuff/story"></iframe>Second step is to ask the internet if anyone has done it before so I can lean on your workThanks for any help / tips / advice and I'll share any future succcess with you all.Cheers!

author: ptrax
author_rank: Newbie
timestamp: December 22, 2018, 04:47:03 am
content: how's it going , any success this looks similar to my controller which died a few weeks ago.So I would really like to know if this is some sort of serial connection similar to the Reverse cycle A/C postedhere.So I tool would like to know if I can insert a arduino or ESP8266 device to control my Evaporate cooler.

author: Rerouter
author_rank: Super Contributor
timestamp: December 22, 2018, 05:00:19 am
content: Its a little hard to work from your pictures (extreme angles, rather than flat)But from that 4 pin connector at the bottom, you have Ground to plane, the fat trace will be power, The third pin connects directly to the pic microcontroller from what I can see, and while I cant see what the 4th pin does, I suspect another data line or as simple as not being presentIf its 1 data line, I would expect something similar to K-line, an older industrial 1 wire protocol, Its pull down only,If 2 wires, then maybe something else. if its direct to the CPU there are not many things it could be.

author: ptrax
author_rank: Newbie
timestamp: December 22, 2019, 03:07:57 am
content: any progress on getting some automation?
Seemingly differential simulation? - Page 1
Forum section: electronics / projects

author: Things
author_rank: Regular Contributor
timestamp: December 17, 2012, 11:21:11 am
content: Hey all,I'm using the little Java circuit sim to try out some battery control here with MOSFETs, but i'm seeing some strange behaviour. My thoughts are that the simulator isn't getting the "ground" references correct, and as such, is using the 2 terminal inputs as differential inputs?Is this just a referencing issue with the simulator, or am I actually doing something wrong here?I also have an odd issue where if the threshold voltage of the MOSFET is set below around 2V, it allows current to leak through? I've heard this sim isn't the most accurate for MOSFETs, but is my circuit sound?Cheers,Dan

author: PA0PBZ
author_rank: Super Contributor
timestamp: December 17, 2012, 11:39:01 am
content: Quote from: Things on December 17, 2012, 11:21:11 amI don't get it either, where is your ground?

author: Things
author_rank: Regular Contributor
timestamp: December 17, 2012, 11:41:48 am
content: There is no ground, this is a purely battery battery based system. Although in terms of what the control electronics are referenced to, this point under the blue arrow is "ground", as the 25V is the pack that will be powering the system:I tried putting a ground reference in that position, but it did not do anything.

author: PA0PBZ
author_rank: Super Contributor
timestamp: December 17, 2012, 11:51:16 am
content: Quote from: Things on December 17, 2012, 11:41:48 amOk, but if you expect the simulator to put out some meaningful values which you expect to be referenced to something, then put a ground on that something.The bottom connection of the battery would be a nice candidate, try it.

author: Things
author_rank: Regular Contributor
timestamp: December 17, 2012, 11:52:47 am
content: Sorry, just updated my last post with more specific info.Circuit ishereif anyone can be bothered checking it out in the sim.EDIT: OK, I think I've figured out how this is meant to work. THis section of the circuit is meant to be controlled by a IC internal to the batter pack, thus ALL output (That isn't the pack's internal protection circuitry), should be taken from the DSG FET's output pin. This way a -3V "ground" will be the ground for all external electronics to the pack, which is fine.The problem is, i have a microcontroller I want to have control over the DSG FET also, along with the batter management IC. If I use the DSG output as the uC's ground source, it'll mean that the DSG FET will never come on, because the uC will never get power, to in turn enable the FET. Am I right in thinking an isolated power supply for the uC might be my only solution here?
Seen this connector? - Page 1
Forum section: electronics / projects

author: ArcadeTV
author_rank: Contributor
timestamp: February 10, 2018, 02:40:00 pm
content: I'm desperately looking for a socket.Labeled "AMP" from a SuperNintendo Controller.2.0mm pitch, angled.Looking for a drop-in replacement for a pcb-project.Changing the connector on the cable is unfortunately not an option,it has to be plug'n'play for the user.Any help is very much appreciated,Thanks guys!
Sega Mega Drive/Genesis in native 1080p - Page 1
Forum section: electronics / projects

author: mike2156
author_rank: Newbie
timestamp: February 17, 2015, 08:05:55 pm
content: I've been following a forum post on sega-16.com for some time now.Jorge Nuno is undertaking a project to bring the retro beauty that is the Mega Drive into the modern era by hacking the graphics chip, intercepting the colour channels and running them through an adc circuit.http://www.sega-16.com/forum/showthread.php?13780-Genesis-does!-1080p/page4I feel like he's perhaps lost steam on the project and wondered if anyone here had any thoughts on this project as it would be a fantastic thing to get working.

author: Whales
author_rank: Super Contributor
timestamp: February 17, 2015, 11:31:35 pm
content: If he's gone to composite video sampling, that's sad. Products already exist to do that (minus the neat integer upscaling + windowboxing)I have not opened up my megadrive before, but I a bevel-cut pcb could be a great way to attach to the 60 odd digital lines if he is still worried about that being a pain. ala whatbunnie Huang did when hacking the xbox.The "Bunnie Bevel"

author: mike2156
author_rank: Newbie
timestamp: February 21, 2015, 10:11:15 am
content: Yup, if he's just building a standard (Grainy ass composite) up scaler that's no better than all of the other boxes out there, I'd like to see a real hard mod that takes the raw data from the processor and natively scales it to 1080p. essentially replacing the encoder chip.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: February 21, 2015, 12:51:02 pm
content: Seems to me, there should be enough documentation out there to implement the original chip, on the pin level, in an FPGA, with whatever output tricks you like ('nearest' upscaling, bilinear filter, palette tweaks, etc.). Substitute would then be little more than a plug-in board and replacement DIP socket.Tim

author: krivx
author_rank: Frequent Contributor
timestamp: February 21, 2015, 01:04:45 pm
content: Quote from: T3sl4co1l on February 21, 2015, 12:51:02 pmThere have been projects like this but it's a huge amount of work to get compatibility good enough. This was hardware that was misused/abused for interesting effects, even software emulation took a long time to get to the stage where all available code would run correctly.
Segger emWIN: How to wrap text in BUTTON?? - Page 1
Forum section: electronics / projects

author: jtronix
author_rank: Regular Contributor
timestamp: June 18, 2015, 04:27:43 am
content: Hello,i want to wrap text in widget especially in Button but segger library doesn't provide direct function for text wrapping.In attach file i've shown Hello Word example, top button has string "Hello World" whereas in second Button Hello displayed in first line and World in second.kindly provide any commad or other way to do text wrapping in Button
selectable bnc terminator - Page 1
Forum section: electronics / projects

author: Deathwish
author_rank: Unknown
timestamp: November 09, 2015, 11:05:08 pm
content: I am thinking of making my own selectable bnc terminator. I am thinking along the lines of a very small piece of pcb with a soldered edge mounted bnc on one end and perhaps a connector at the other that is spring loaded which will hold a SMD resistor that you can insert as needed. what do you think ?

author: timb
author_rank: Super Contributor
timestamp: November 09, 2015, 11:11:06 pm
content: You can buy something similar on eBay from China. It's a PCB with end launch BNC connectors on both ends and resistors in Pi or T attenuator configurations. They sell for about $5 a pop in any attenuation range you want.If you just want termination, bridge the top of the T and solder the termination value you want on the bottom pad. Would be a lot cheaper than making your own.Sent from my Tablet

author: Deathwish
author_rank: Unknown
timestamp: November 09, 2015, 11:14:18 pm
content: Quote from: timb on November 09, 2015, 11:11:06 pmSigh, i am always last of the boat !. Thanks Timb. Maybe my idea would be ok if I was in a rush or desperate and at home on the bench. Oh well.

author: Matje
author_rank: Regular Contributor
timestamp: November 09, 2015, 11:29:04 pm
content: Quote from: Deathwish on November 09, 2015, 11:05:08 pmWon't do you much good.First, the BNC connector itself has a defined impedance. There are actual mechanical differences between 50 and 75 ohms AFAIR. No, really, read the datasheets.Second, a contraption with some changeable SMD resistor (or whatever) is not going to be reliable or well-defined. Good terminators (actually good connectors in general) are not cheap, for a reason. If you have seen your first cheap BNC 50 ohms terminator losing it's cap, and then have seen what's beneath (in my case: a through-hole resistor, crimped into the center pin and connected to the outer conductor by mere mechanical contact...) - you will understand ;-)Basically, you either work a frequencies so low correct termination won't matter much anyway or frequencies so high it won't work properly, ever.
Selecting 5mm LED's provider for outdoor use - Page 1
Forum section: electronics / projects

author: e.sotillet
author_rank: Contributor
timestamp: June 19, 2023, 12:49:30 pm
content: Hi FolksI have been working with LEDs indoor seven segment displays for a long time. Now, I'm moving to outdoor applications, where more demanding conditions shows up, specially direct sun light.Keeping in mind the basic rule of driving the LED's with constant current circuit:a) ¿what else should I take in acount?b) ¿How I can select a suitable 5mm LED for this application?c) ¿How I can filter good quality LEDs supplier from garbage ones? (Considering that the failiture of the LED can take a couple of thousand hours)I usually perform the burn out test for quality control but I want to have a broader picture of the aspects to consider.Best regards
Selecting a conformal coating - Page 1
Forum section: electronics / projects

author: Psi
author_rank: Super Contributor
timestamp: January 25, 2021, 10:33:53 am
content: What's a good general-purpose conformal coating to ask the PCB fab for?Something that's provides moisture protection but doesn't cost too much.The PCB is automotive but given it's location it will not be subjected to any solvents.Moisture/humidity is my only reason for getting a conformal coating.Any suggestions?I'm thinking Acrylic?

author: tszaboo
author_rank: Super Contributor
timestamp: January 25, 2021, 10:58:57 am
content: If you want to outsource it, just ask them what they usually use.They will have a standard material, and if you dont have any special requirements, that will be OK 90% of the time.Otherwise if you are not happy with the result, ask for something UL listed.

author: coromonadalix
author_rank: Super Contributor
timestamp: January 25, 2021, 06:05:53 pm
content: chemtronics konform ar can't recall how much a can cost

author: Niklas
author_rank: Frequent Contributor
timestamp: January 25, 2021, 06:27:08 pm
content: What is the maximum operating temperature? Some types of coating are not suitable above +85'C.

author: jkostb
author_rank: Regular Contributor
timestamp: January 25, 2021, 07:07:33 pm
content: I have used in past mainly conformal coatings from Humiseal (e.g. UV40-250, 1B93 etc). Some coatings need to be sprayed once, other need to be applied in 2 layers. Please have a look at website of Humiseal. Most PCA assembly houses use standard one type of coating. Switching to other type means flushing machines etc. So you better ask your production facility what the default coating is they use.

author: Niklas
author_rank: Frequent Contributor
timestamp: January 25, 2021, 09:45:07 pm
content: Quote from: Niklas on January 25, 2021, 06:27:08 pmSome requirements from an automotive customer:Above +85'C, (ER) Epoxy, (SR) silicone and (XY) Parylene acceptedBelow +85'C, (AR) Acrylic, (ER) epoxy, (SR) silicone, (UR) urethane and (XY) Parylene accepted.And a note that silicone coating is not recommended for applications with possible high amounts of sulphur vapors as it can be aggressive on silver and damage components.

author: Psi
author_rank: Super Contributor
timestamp: January 26, 2021, 06:52:02 am
content: Thanks.One of the chips may get over 85C if the ambient temp is really high.
Selecting a line in an LTSPICE simulation? - Page 1
Forum section: electronics / projects

author: Pack34
author_rank: Frequent Contributor
timestamp: September 24, 2017, 02:26:19 am
content: I'm ramping a component's value to find the optimum. Is there a way to tell what value corresponds to which line other than iteratively reducing the window of the ramp?How do I know what value of {X} corresponds to Blue? Red? Teal? Magenta?

author: orolo
author_rank: Frequent Contributor
timestamp: September 24, 2017, 09:22:02 am
content: Not exactly what you are asking about, but a workaround: you could use the.meascommand to sort out which which value of the parameter fits your requirements.For example, in your simulation using:.meas TRAN adcpeak FIND V(adc) AT=70ushould tell you which parameter corresponds to each curve.

author: Dave
author_rank: Super Contributor
timestamp: September 24, 2017, 03:05:14 pm
content: You can click on the graph legend to get a cursor, which you can move around by dragging it with a mouse. You can then switch between traces with up and down arrow keys and you can right-click the cursor again, to show which trace you are observing.Not the most convenient way to do it, but that could be said for LTspice in general.

author: Cerebus
author_rank: Super Contributor
timestamp: September 24, 2017, 05:02:27 pm
content: Do you mean you are using .STEP?If so, right click on the graph, View, Select Step and you'll see an entry for every step. There's no legend, you just have to select them in turn to work out the colour scheme in use. Yes, not particularly satisfactory, but that's how it is.

author: Pack34
author_rank: Frequent Contributor
timestamp: September 25, 2017, 02:54:07 pm
content: Quote from: Cerebus on September 24, 2017, 05:02:27 pmDoes what I need it to. Thanks!
selecting a signal connector - Page 1
Forum section: electronics / projects

author: kuon
author_rank: Regular Contributor
timestamp: February 09, 2021, 04:44:59 am
content: I know this has been asked a million times, I read many things, but I still would like your advice on a connector selection.I want a connector to connect a load cell to a PCB. I need- 5 circuit (4 + cable shield actually)- good signal integrity as I am measuring uV- easy to mate/unmate without tools- full smt- audible click on assembly- right angled- 1.5-2.5mm pitch- ambient temperature and no vibration, so no requirements on this sideSo far I have found:- molex nano fit- molex micro lock- molex micro one- molex clik- hirose DF3EABut I don't know which to choose.

author: tooki
author_rank: Super Contributor
timestamp: February 09, 2021, 07:06:10 pm
content: A key spec in small connectors is how many insertion cycles it needs to support. Some connectors can handle dozens or hundreds of cycles, others are pretty much designed to be plugged once and that’s it.

author: kuon
author_rank: Regular Contributor
timestamp: February 09, 2021, 07:35:07 pm
content: A dozen of cycle is enough to maintenance. But not "once". I tried some JST connectors, but they are nearly impossible to unplug properly.All the connector I selected have a durability of 30 cycles, except nanot fit which has a 50 cycle option.

author: tooki
author_rank: Super Contributor
timestamp: February 10, 2021, 05:12:54 pm
content: Quote from: kuon on February 09, 2021, 07:35:07 pmJST has dozens of different small signal connectors. They vary dramatically in ease of insertion/removal. I’m a big fan of JST XH, as it uses the “folded beam” contact style that is very robust, but is cheap and reasonably compact. But there are also ones with latches (which provide positive retention, but comparatively easy removal).That hirose series looks nice, as a complete wire to board, wire to wire, and board to board system.
Selecting coupling capacitor size/type - Page 1
Forum section: electronics / projects

author: SethGI
author_rank: Regular Contributor
timestamp: April 23, 2017, 03:15:15 pm
content: Hello,I am working on a sonar project, and building a board to sit between the microphones and the DAQ to supply a bias voltage to the microphones. I then need to remove that bias with a coupling capacitor. How do I select the value of that cap? The input impedance of the DAQ is 1 mega ohm. It's a 9v bias. I've also heard that mylar caps would be better than ceramic as ceramic can introduce distortion. Is this true?I attached an image of the circuit.Thanks,Seth

author: Wimberleytech
author_rank: Super Contributor
timestamp: April 23, 2017, 04:03:39 pm
content: f(3dB) = 1/(2pi*RC) R = 1Meg, pick your 3dB freq., calculate C.Since this is a high pass filter, you need to pick the lowest frequency you expect to amplify.

author: TimFox
author_rank: Super Contributor
timestamp: April 23, 2017, 09:02:40 pm
content: Capacitor C10 will block the DC bias from the microphone connection.
Selecting inductor and capacitor values for tracking preregulator? - Page 1
Forum section: electronics / projects

author: conducteur
author_rank: Regular Contributor
timestamp: August 14, 2019, 01:39:48 pm
content: In a tracking-preregulator (buck converter), how do you calculate the values for the inductor, output capacitor and flyback diode? Do you use maximum current and maximum voltage difference in vs. output?

author: MagicSmoker
author_rank: Super Contributor
timestamp: August 14, 2019, 01:51:27 pm
content: If the buck has to deliver a wide output voltage range as a preregulator then the L, C and FWD component values will necessarily be a compromise. The worst case for the inductor and capacitor are when Vo = 0.5 * Vin; the worst case current rating for the FWD occurs when Vo is at a minimum (typically 2V - 4V higher than the output voltage of the post-regulator).
selecting inductor for synchronous buck - Page 1
Forum section: electronics / projects

author: tictactoe
author_rank: Newbie
timestamp: April 11, 2018, 11:52:57 am
content: HiI want to design the synchronous buckVin=14 volts to 35 voltsVout=1 volts to 12 voltsIout-max=50 ampereFrequency=100 khzI want to select the output inductor capable of passing through 50 amperes with the inductance about 1.5 uH.Please help me about the core material and shape of this inductor and see all the specifications for this inductor.Regards

author: KhronX
author_rank: Frequent Contributor
timestamp: April 11, 2018, 09:48:05 pm
content: https://www.mouser.fi/Passive-Components/Inductors-Chokes-Coils/Fixed-Inductors/_/N-wpcz?P=1z0wrhx&Rl=wpczZer9dZ1z0wq9sZ1yxtezeSGT&Ns=Pricing|0
Selecting input / output capacitors for LDO regulators - Page 1
Forum section: electronics / projects

author: ilium007
author_rank: Frequent Contributor
timestamp: August 22, 2021, 03:32:46 am
content: I am putting together a breadboard power supply (first SMD reflow board I have designed) and I am trying to work out why some of the same LDO circuit designs use input and output capacitors different to those specified in the manufacturer datasheets. I know the input one is there to prevent oscillations and the output one is to help with ripple (??) but how does one come up with 10uF / 0.1uF on the input and 22uF / 0.1uF on the output as shown in the Espressif design vs. the 4.7uF shown in the AP7361C LDO datasheet (https://www.diodes.com/assets/Datasheets/AP7361C.pdf) shown below?On this design there are input / output capacitors on the LDO's but then a 'Power Filtering' bank of electrolytic capacitors, 10uF and 47uF, on the outputs of each LDO.
Selecting low power monolithic boost controller - Page 1
Forum section: electronics / projects

author: makebit
author_rank: Unknown
timestamp: October 02, 2025, 08:41:44 pm
content: Hi,Muggins here agreed to get a PCB done for tomorrow,But didnt realise how long it would take to find a low power monolithic boost controller IC.All we need is vin 2v7 to 10V, Vout = 5V, iout = <20mA.But the ti.com search engine just crashes every time i try and sort by a column.I know ti.com are the best for this, does anyone know a part number off the top of their head?

author: langwadt
author_rank: Super Contributor
timestamp: October 02, 2025, 08:44:29 pm
content: for Vout < Vin a regular boost won't do

author: makebit
author_rank: Unknown
timestamp: October 02, 2025, 08:58:33 pm
content: Thanks, yes, vout will always be > vin....we want "vin_withstand" to be high enough so that sudden vin connection doesnt "LC ring up" and blow the input voltage pin.So Vin could be 4.3v and sudden, so anything up to 10v input withstand is preferred.As discussed, the ti.com search engine is crashing, so we are just going through one by one.....and so far, LM27313 is the lowest power with an 800mA switch current limit...but i am sure there is lower than that.I always used to use a richtek one with a 20ma current limit, but it must now be obselete.

author: langwadt
author_rank: Super Contributor
timestamp: October 02, 2025, 09:11:14 pm
content: Quote from: makebit on October 02, 2025, 08:58:33 pmbut if Vin is 10V so is Vout

author: PCB.Wiz
author_rank: Super Contributor
timestamp: October 02, 2025, 09:46:22 pm
content: Quote from: makebit on October 02, 2025, 08:58:33 pm20mA has been competed out of the market.TI says this about LM27313A newer version of this product is available: Pin-for-pin with same functionality to the compared deviceTLV61047 NEW ACTIVE20VIN, 28VOUT, 2.2A non-synchronous boost converter with SOT23-5 DDC package Wider input voltage and higher efficiency. Iq (typ) (µA) 25Addit : over at lcsc this may be an alternative Quiescent Current 100uA Operating Voltage 2.2V~16Vhttps://www.lcsc.com/product-detail/C2974847.htmland slightly lower indicated Iq Quiescent Current 50uA Operating Voltage 2V~24Vhttps://www.lcsc.com/product-detail/C5123435.html
Selecting the correct common mode choke - Page 1
Forum section: electronics / projects

author: gnif
author_rank: Unknown
timestamp: November 24, 2018, 12:36:33 am
content: Hi All,The audio bug has bitten me again and I am currently in the process of re-designing my pre-amp power supply. In my office there is a fair amount of common mode noise I would like to filter out, but having never used a common mode choke before and being a little bit lost with the right inductors to use, I would use some advice.It is a linear +/-15VDC unit, I have already recycled some parts out of a washing machine for the Mains AC side of things (230V), including a chunky common mode choke and so far the output of the supply is 2-3x cleaner then my prior attempt, however I feel that more could be filtered out after the toroidal transformer which is about 22V AC ptp. The choke I pilfered likely isn't right for the job, but it was free.So my questions are:* Should I use a low voltage choke after the transformer also?* What value should the choke be to filter as much noise as possible.* Please explain the selection of choke so that in future I can figure this out for myself

author: tautech
author_rank: Super Contributor
timestamp: November 24, 2018, 03:50:40 pm
content: You shouldn't need a common mode choke on the LV side of a linear supply, period .....if the rectifier and smoothing caps are doing their job. No need to use low ESR caps with a linear supply either but add some faster ceramics near the output to catch any errant spikes.What regulation are you using ?With just jellybean LM7815 and 7915 the output should be pretty clean.

author: gnif
author_rank: Unknown
timestamp: November 24, 2018, 09:54:31 pm
content: Before the changes I was seeing 25-30 mv peak to peak common mode noise.Yeah, I am using the LM7815 and LM7915 regs. The output is pretty good, but there is common mode noise of roughly 10mv peak to peak at the output. It could however be the scope picking up noise from the room, I am not sure. I have a 4700uf cap before each reg, and a couple of 100n poly film caps, one before and one after each reg.

author: tautech
author_rank: Super Contributor
timestamp: November 24, 2018, 10:09:15 pm
content: Quote from: gnif on November 24, 2018, 09:54:31 pmThat would be my first suspect and a different scoping method should be able to confirm it.1x probe with a short reference lead or the little springy clip that you should have in your probe pouch.Some small load on the output can be necessary to settle the output to 'real world' operation.
Selection of BLE chip and stack  - Page 1
Forum section: electronics / projects

author: abhishekkumar1902
author_rank: Regular Contributor
timestamp: September 17, 2018, 07:33:07 am
content: I am new to Bluetooth in terms of its use and deployment in the embedded systems particularly when it comes to the selection of BLE chips, BT stacks, profiles, etc. I am planning a project in which I would be needing a BLE chip (& stack) which:1.) can connect to at least 7 external sensors hosting profiles like Heart-rate, blood-pressure, indoor positioning, location & nav, etc2.) can simultaneously act as a host to let an external wireless remote LCD display connect to it and send/receive display/HMI data to (maybe using some customized profile, etc)I am looking for advice in terms of selection of the best BLE chip (& vendor) possible which has good support in terms of ecosystem/dev-tools, shorter time to market, etc. Also, I wanted to know if these BLE profiles can be integrated into the BLE chip's firmware itself that can be selected and controlled through an external host MCU, or is it also possible that these profiles can sit on the external host MCU itself.Thanks in advance!

author: taydin
author_rank: Frequent Contributor
timestamp: September 17, 2018, 09:09:00 am
content: I would recommend using GNU/Linux for the software. It has a complete bluetooth stack (Bluez), is free software, and you are much more likely to get support if you run into issues. The downside would be that documentation is scarce, so you have to be ready to read the source code if you want to know how it will behave under certain conditions and that aspect is not documented.Regarding modules, I have been using only WIFI/BT combo modules, no standalone BT, so I don't have anything to recommend ...

author: abhishekkumar1902
author_rank: Regular Contributor
timestamp: September 17, 2018, 10:30:39 am
content: I want to deploy this on a STM32 mcu which is running freeRTOS. I basically wanted a separate BLE chip which can also contain the BT profiles so as to offload the mcu from any extra processing!

author: cgroen
author_rank: Unknown
timestamp: September 17, 2018, 04:02:53 pm
content: I use CYBLE-212019 with success. Has a default firmware installed (Ez-serial) which makes it easy to use.Other of the CYBLE products are even smaller footprints

author: AloyseTech
author_rank: Regular Contributor
timestamp: September 18, 2018, 09:40:54 pm
content: I had multiple project using the BGM121 from Silabs (Any EFR32xG actually). They are nice to work with. The stack is easy to use and the profile configurator is great.
Selection of transmitter/receiver for remote controlled car - Page 1
Forum section: electronics / projects

author: larsdenmark
author_rank: Regular Contributor
timestamp: June 01, 2023, 11:31:42 am
content: I want to make a remote controlled car, but need help for choosing the transmitter/receiver technology.Maximum distance is 50 m. Both the controller and the car should be able to send and receive. I would like to be able to equip the car with a camera, but the image doesn't have to be live video.What technology is the easiest to interface to? I'm used to work with ESP32, RP2040 and Arduinos. My preferred language is C/C++.

author: Benta
author_rank: Super Contributor
timestamp: June 01, 2023, 06:35:30 pm
content: 2.4 GHz is pretty standard these days for two-way R/C. Check out Graupner/JR or Robbe.https://www.graupner.com/bbs/board.php?bo_table=a_001https://www.robbe.com/en/navigation/dbf2bca444a94a8ea02417e47a671306

author: larsdenmark
author_rank: Regular Contributor
timestamp: June 02, 2023, 06:06:11 am
content: Thanks.I would like to be able to transfer images from the car to the controller. The 2.4 GHz controllers you link to do not seem to support that. Also I had hoped I could build something that would cost less than 1000€

author: Georgy.Moshkin
author_rank: Frequent Contributor
timestamp: June 03, 2023, 03:41:51 pm
content: I would use nrf24l01p for control and esp8266 for images (wifi). Need to put some efforts to make work seamlessly.
selective filter circuit for analog demand signal in servo drive - Page 1
Forum section: electronics / projects

author: Apothus
author_rank: Contributor
timestamp: October 24, 2016, 12:57:03 am
content: I am looking for a shove in the right direction with this problem.We use servo amplifiers as part of our control system for a linear actuator. We also have limit switches to stop the actuators turning into paperweights.The demand signal for the amplifiers is a +/- 10V signal from a DAC or a manual override pot.I need to derive some protection circuit that will allow me to filter out only positive or negative demand signals based on the status of the limit switches (inverted logic for safety).The circuit does not need to be fast as our actuators are pretty slow however we need to maintain a full scale signal as we do use the full range, so we cant just cut in diodes.

author: Apothus
author_rank: Contributor
timestamp: October 24, 2016, 05:20:15 am
content: That info is fantastic thanks evb149!It has certainly given me plenty to look at. I like the idea of the precision rectifiers but I think the comparator circuit will be the easiest to implement and have the least effect on the demand signals during normal oppration.
Self assembling electronics - Page 1
Forum section: electronics / projects

author: zapta
author_rank: Super Contributor
timestamp: June 08, 2014, 04:20:53 pm
content: Who needs assembly line...

author: Legit-Design
author_rank: Frequent Contributor
timestamp: June 08, 2014, 04:29:17 pm
content: Can chip printer print on the same material?
Self healing potting compound in Aus? - Page 1
Forum section: electronics / projects

author: e100
author_rank: Frequent Contributor
timestamp: April 19, 2014, 03:15:48 am
content: Does anyone know where in Aus I can buy self healing potting compound like the stuff used in the parachute release teardown.http://www.eevblog.com/2012/08/22/eevblog-339-cypres-parachute-aad-teardown/ROBNOR EL583c is one type but Element14 no longer carry it in stock. It a polyurethane resin.http://www.robnor.co.uk/images/technical/pu/Updated/el583c.pdfThere's also Raytech 'Magic gel' which is sold as a cable jointing resin and is readily available in Aus but I couldn't find any info on using it for electronics. This is a silicone gel.My need is for protecting electronics against condensation in an outdoor environment.Mike
Self-levelling laser level - Page 1
Forum section: electronics / projects

author: BurningTantalum
author_rank: Frequent Contributor
timestamp: October 16, 2018, 12:44:10 pm
content: A friend acquired a cheapy laser level, of the type used in building work. It was new to the previous owner but had a fault in that it does not auto level.It has a a pair of motors driving jackscrews to adjust the platform holding the rotating laser head. I cannot find any information on the net on how the electronics detects 'level', and nothing seems to be obvious.Does anyone have any idea how this system works?The supplied manual is a very poor example of 'Chinglish' and no calibration or set-up procedure is documented.Regards, BT.

author: H.O
author_rank: Frequent Contributor
timestamp: October 16, 2018, 12:47:20 pm
content: Most likely a MEMS accelerometer.

author: BurningTantalum
author_rank: Frequent Contributor
timestamp: October 17, 2018, 08:02:07 am
content: Thanks for that info- plenty to read on that subject!I'm still not sure if there has been a fault from new, or we have not found the calibration procedure but the instrument doesn't seem to realign itself in 'Auto' when disturbed, but pauses and then sets off spinning again as if it had. One for a rainy day, I think...Thanks, BT

author: H.O
author_rank: Frequent Contributor
timestamp: October 17, 2018, 10:03:40 am
content: Those that I've come in contact with (which, granted, aren't THAT many), both professional grade and cheap stuff from the DIY store has not had any calibration procedure described in the manual. I suppose if you take them appart you might be able to mechanicaly adjust the relationship between the leveling platform and the acceleromenter but, I have not seen any sort of "user calibration" on them.You say it spins. When it does, is the laser actually on? That would be a bad thing if it's not actually leveled. I mean, sure it can THINK it's leveled but since the platform doesn't move the neither should the output from the accelerometer, yet it does sense when its being bumped.Perhaps it's a manufacturing problem, putting the accelerometer on the board in the wrong orientation. Does it do anyting differently if try laying it down its side so it throws a line around vertically instead of horisontally?
Self OSC SMPS AT-ATX Transformator (No rewinding required) - Page 1
Forum section: electronics / projects

author: gevv
author_rank: Contributor
timestamp: March 23, 2024, 10:39:56 am
content: Hi, Cheap, simple switching power supply SMPS circuit was tested with a cordless drill, current was drawn over 20 amps, and LM3886 amplifier was tested.
Self Powered Current Measurement - Page 1
Forum section: electronics / projects

author: wigman27
author_rank: Regular Contributor
timestamp: April 03, 2014, 09:03:40 am
content: Hey all,I am working on designing a power meter. I know you may say there are hundreds out there however, I would like mine to be a little different (from any I have seen anyway). I am planning on having a base unit (Beaglebone or similar) inside with remote current measurement in the main switchboard or somewhere else. These current measurement devices would be interrogated at a certain interval and logged online directly.My main question is, is there a way to successfully power the current measurement unit (CT or hall effect) using induction? would I be able to power the device using the output of the CT? Even if I have a small lithium battery built in that charges itself when the unit is not being interrogated for data to smooth and regulate the supply.I am guessing its not, but I just wanted to put it out there and see what you thoughts where.Also, side note.Is there such a thing as a compact 3 phase plug in Australia? about the size of a standard power point?Lee

author: wigman27
author_rank: Regular Contributor
timestamp: April 03, 2014, 09:17:58 am
content: I obviously forgot to mention that I need to power the CT as well as associated control gear and transmitter

author: HackedFridgeMagnet
author_rank: Super Contributor
timestamp: April 03, 2014, 10:13:13 am
content: QuoteNo it is a fair bit biggerhttp://www.fastlec.com.au/p/Industrial/IP66-Switchgear/10A-5-Pin-Straight-IP66-3-Phase-Plug/IP-PLS3PH510?gclid=CJKVhoaJxL0CFRRxvAodrDEApgQuoteYou could do it theoretically, but you wouldn't be allowed to in Australia and it would be an unnecessary hassle as you would need probably more than one turn of an individual conductor, not the whole sheathed cable.The easy way is just use the mains and get the volts. You already have accessible terminations in a switchboard.QuoteActually the CT is the only thing you dont need to power.

author: David Hess
author_rank: Super Contributor
timestamp: April 03, 2014, 06:53:30 pm
content: Quote from: wigman27 on April 03, 2014, 09:03:40 amThis is certainly possible to do. The switching power supplies in the old Tektronix 7000 series oscilloscopes power the primary side switching regulator control circuits, which are galvanically isolated from the line input, completely from the primary side current sense transformer.The big problem I see though is that 50/60 Hz current transformers are intended to operate below a specific burden voltage. At higher voltages, the transformer will saturate. You can see this effect in current probes where using a low impedance load, often provided by a virtual ground, allows lower frequency operation. To get around this either the transformer will have to be a custom model intended to operate with a higher burden voltage or another transformer could be added to step up the low voltage output.Available output power will depend of course on the minimum primary current.
Self-protected battery current protection  - Page 1
Forum section: electronics / projects

author: Diablo2813
author_rank: Newbie
timestamp: September 05, 2019, 03:04:18 pm
content: Hello,This is an ATEX project.I'm working with a low voltage battery (2.4 to 4.5V).The maximum absolute ratings all have to be over 7V and able to work in my battery voltage rangeIn order to protect my battery, this are my points of interrest :– Overvoltage Detection (OVP)– Charge Overcurrent Detection (OCC)– Discharge Overcurrent Detection (OCD)– Load Short-Circuit Detection (SCP)The component bq297xx from Texas Instrument should work fine for most of my needs BUT I need it to be self-protected from short-circuit in order to be sure there will be none.One way would be adding a resistor to its Vss to limit the short-circuit current but it lead to more and more difficulties in order to get it works.Another would be to add a self-protected short-circuit protection device before the bq297xx that I cannot find.My best lead was the LT6118 from Microchips but its minimal voltage is too low in order to add a resistor to its ground.Is the own short-circuit of the protection devices something that someone else is caring about ?Thanks for your responses.
Self-Soldering PCB - Page 1
Forum section: electronics / projects

author: metrologist
author_rank: Super Contributor
timestamp: January 20, 2023, 11:14:08 am
content: Ovening, it's a verb, YO!

author: Shay
author_rank: Regular Contributor
timestamp: January 20, 2023, 11:48:07 am
content: This is really cool. But how is it any useful? Additional layer is more expensive to manufacture, and I don't find any real advantage in such thing.

author: inse
author_rank: Super Contributor
timestamp: January 20, 2023, 11:54:12 am
content: Agreed, though it’s actually hot, not cool.
Self starting SMPS working? - Page 1
Forum section: electronics / projects

author: Achu
author_rank: Contributor
timestamp: October 17, 2019, 04:53:24 pm
content: Hi,Could any body explain it to me how this self starting SPMS PSU work?I have seen only those with auxilliary power supply.

author: Miyuki
author_rank: Frequent Contributor
timestamp: October 17, 2019, 05:03:48 pm
content: It is same as for example small two transistor astabile oscilatorOr other self oscilatin smps, commonly flybacksTransistors have positive feedback from that small transformer and without controll signat it wil oscilate itself from saturation to saturationIt starts because it have no stable state in middle

author: T3sl4co1l
author_rank: Super Contributor
timestamp: October 17, 2019, 07:04:28 pm
content: Wow, that's a nearly perfect circuit. I am impressed!The only things I can complain about are perhaps the aux supply being cap-input filtered, where maybe some series resistance would be wise to take the edge off charging C27; and it would be nicer to have cascaded current and voltage error loops, but that does require one more op-amp to pull off. Of course these days, PFC would be nice as well, but for the time, this is absolutely fine.Anyway, starting has to do with the high value resistors on the base drive circuits. I've never built an inverter like this before (with the bias resistors), but I believe the way it goes is, the BJTs are biased slightly on (10s mA?), which gives gain, and pretty soon due to positive feedback (through the drive transformer -- note the load current flows through it) it saturates in one direction. Then probably due to transformer saturation (but if not, then probably the drive capacitors charging up), drive abruptly stops, and reverses; the system is symmetrical so the process repeats.Once aux supply comes up, the TL494 acts tostopthe self-oscillating inverter. This is why the drive is inverted by two extra transistors -- the default "idle" state is with both transistors on, holding the drive transformer voltage at zero.It's a nice way to drive BJTs, as, for merely the cost of an -- admittedly rather complicated -- transformer, you don't have to worry about base current or voltage, or drive power, or hFE at all -- that's all handled by the transformer, and the transistors just latch on and run themselves. It's effectively making each transistor into a dynamic SCR -- one that stays latched on for a limited time.I have however made a half-wave version, here:https://www.seventransistorlabs.com/Images/LED_Light2.pngwhere the switch operates as a one-shot timer. The control circuit triggers the switch by pulsing the drive transformer; the switch stays saturated for about 5us, at a forced hFE of about 15t / 3t = 5. After that, the ferrite core saturates, shorting out base current and rapidly switching off the transistor. After a brief reset pulse (not handled by anything shown here; I later put a P6KE15CA across the 60t primary to limit peak voltage), the switch is ready to go again. The control just acts as a frequency modulator, generating pulses to maintain constant output current. This is also known as a constant on-time control.Tim
selfheat MAX31855 - Page 1
Forum section: electronics / projects

author: RR
author_rank: Contributor
timestamp: October 29, 2013, 01:22:49 pm
content: HiI have built a simple circuit with MAX31855 thermocouple amplifier. Comunication work well but chip heat itself fast to 45-47°C and still slowly gaining (readed from internal sensor) And by touch chip and pcb around is really warm so its not bad reading. Its powered from 3.3V LDO(real voltage 3,26V), 0.1uF cap close to vcc used as well. I have no idea what is wrong any suggestions?Thanks!

author: minime72706
author_rank: Frequent Contributor
timestamp: October 29, 2013, 03:01:48 pm
content: Well... it sounds to me like there is something wrong with the chip. It should only be dissipating single-digit milliwatts of power. It's supply current is rated to be less than 2mA and you're running it from 3.3V ... do the math. The chip has definitely suffered some kind of failure - maybe latch-up.
Sellers of ESP-01's with deep sleep RSP/XPD_DCDC pins already soldered? - Page 1
Forum section: electronics / projects

author: ziplock9000
author_rank: Regular Contributor
timestamp: June 10, 2020, 05:45:58 pm
content: I've been trying to solder the RST and XPD_DCDC pins on the cheap ESP-01's I have and I've found it impossible after several attempts. It's just too small even under magnification for me and the equipment I have.Does anyone know anywhere that sells these already soldered and with AT firmware installed?I tried using an ESP-03 which is easier to solder these pins together, but it just simply would not flash the firmware after screwing will all sorts of pins and trying different setups.Thanks.