hybridfree/eevblog-posts huggingface dataset:
DIY Electronic DC load, just an initial preview - Page 1
Forum section: electronics / projects

author: bsodmike
author_rank: Regular Contributor
timestamp: September 12, 2021, 03:31:59 pm
content: Hi all,This started just out of interest in diving a bit deeper into Opamps and since then I've been having a lot of fun and thought I'd create a DIY Electronic load that I could maybe sell as a kit at some point.Due to this reason, you will find there are some "odd" things going on with the initial prototype - mixing SMD and THT parts, but fear not, these will be cleaned up towards as "production" run.It needed to make a few corrections to get the LCD to light up, and the next stage is to integrate the microcontroller, which will read the load voltage and shut voltage (load current) and display this on the display.Here's a quick progress video on the topic as wellhttps://youtu.be/WmP2RaRIo74Anyways, I thought I'd just share progress for now.Thanks, Mike.
[DIY] Electronics project box fitted on top of a pole - Page 1
Forum section: electronics / projects

author: epigramx
author_rank: Regular Contributor
timestamp: February 06, 2019, 08:04:31 pm
content: I have a pole with a 5/8''-11 screw sticking out the top of it. I have a waterproof 150x90x75mm plastic box with an electronics project in it that I want to fit on the pole (on demand, it shouldn't be permanent).How do I go on about it?I'm currently thinking of getting a 5/8'' nut, sticking it under the box (probably in a hole) and securing it with hot glue.

author: Domagoj T
author_rank: Frequent Contributor
timestamp: February 06, 2019, 09:01:33 pm
content: Perforated metal strip?https://www.alibaba.com/product-detail/perforated-metal-steel-strip_1073108666.html

author: Gregg
author_rank: Super Contributor
timestamp: February 06, 2019, 10:56:27 pm
content: Glue a fiberglass flange nuthttps://www.mcmaster.com/hex-flange-nutsto the bottom of the box with JB Weld. Glue the flange part to the box for more surface area in contact with the glue and use a wrench on the hex to tighten and loosen it. Something like a fiber washer or even a garden hose gasket between the nut and the pole may help keeping it from loosening without having to torque it too much.

author: Dubbie
author_rank: Unknown
timestamp: February 06, 2019, 10:59:29 pm
content: I'd be tempted to ignore the screw and glue a strip of plastic, metal or wood to your box, then ziptie it to the pole. Or hoseclamps if you don't trust zipties.Way less chance of failure if it gets a bump.

author: tkamiya
author_rank: Super Contributor
timestamp: February 07, 2019, 03:34:24 am
content: if you have to take it down often and on demand, how about use of a pulley and a rope? Does it really have to stay on top of the pole?

author: epigramx
author_rank: Regular Contributor
timestamp: February 07, 2019, 06:02:19 am
content: Quote from: Gregg on February 06, 2019, 10:56:27 pmThose are good ideas; a flange nut would be easier to fit and I guess there's no need to make a hole under the box at all; I don't know if I'll find a flange nut easily here but it's a good point nonetheless (and at the very least maybe I can solder a separate flange to it). A soft washer sounds like a nice touch as well.
DIY enclosure idea if you need some inspiration for your own enclosure(s) - Page 1
Forum section: electronics / projects

author: ElectronicSupersonic
author_rank: Regular Contributor
timestamp: May 04, 2019, 03:48:58 pm
content: If somebody is looking for ideas for DIY device enclosure, here is a link to a project I did a while back.http://www.vsdsp-forum.com/phpbb/viewtopic.php?f=9&t=2238In a nut shell, my goal was to create something that can be made using simple production methods from easy to obtain materials.Hopefully it would be of any use to someone.

author: Vgkid
author_rank: Super Contributor
timestamp: May 05, 2019, 05:52:45 pm
content: That looks really good.
DIY Epson thermal printer interface card, which connector? - Page 1
Forum section: electronics / projects

author: dpape
author_rank: Contributor
timestamp: July 12, 2019, 09:44:57 pm
content: Hello,I'm working on a custom interface card for an EPSON TM-T20ii thermal ticket printer. I have successfully reverse engineered the pinout an I can now directly attach to the 3.3V TTL serial input which is available on the internal interface card connector.I want to make several pieces of this card so now I need to source the connector. The problem is that I can't find any markings on the connector and I can't find the correct type. Does anyone have a clue?

author: austfox
author_rank: Regular Contributor
timestamp: July 13, 2019, 02:43:42 pm
content: No doubt an Epson proprietary connector and thus probably hard to get.If you get stuck, try Kel Connectors 8800 series. Looks like a similar PCB footprint, so depending on the flanges, you might be able to make them fit?
DIY Ergonomic thumb switch for e-bike throttle control and electronic gear-shift - Page 1
Forum section: electronics / projects

author: avandalen
author_rank: Contributor
timestamp: October 03, 2023, 12:27:27 pm
content: Efficient speed control is crucial for a comfortable and enjoyable e-bike riding experience. The article HERE presents an innovative solution for speed control through an ergonomically designed thumb throttle switch:https://avdweb.nl/solar-bike/mechanical-issues/diy-ergonomic-space-saving-e-bike-thumb-throttle-switch
DIY ESP32-based Precision Wattmeter - Page 1
Forum section: electronics / projects

author: Prithul0218
author_rank: Contributor
timestamp: January 31, 2024, 06:17:27 pm
content: I was looking for something to build with an ESP32 microcontroller and a little bit of analog electronics twist for fun. I came up with the idea to build a digital watt-meter, like one of those cheap RC hobby ones, but with three improvements - 1. High precision (and accuracy), 2. Datalogging, 3. WiFi connectivity so that multiple of these devices can talk together and calculate efficiency of power supplies.That means if you hook up one of these at the input and the output of your DC-DC converter and have them connected to the same WiFi network, you will have live feed of efficiency and be able to log the data over time without any manual fiddling in spreadsheet softwares.For precision measurement, I have chosen the ADS1256 24-bit op amp and paired it with B grade ADR4525 voltage reference. Voltage divider and current shunt resistors are low ppm as well (10 and 20ppm/C respectively). Right now I have a complete schematic and PCB design waiting for a education sponsorship from a PCB manufacturing company. I wish to share all the resources publicly and hopefully turn it into a community project where more people join in and help improve the design.This is my first time designing a circuit around this ADC and these op-amps. Noise can be a huge issue for the precision and accuracy I am looking for.So TL;DR:I am looking for any feedback/suggestions/advice on my schematic and PCB design.Open design on EasyEDA:https://oshwlab.com/prithul/precision-watt-meter]

author: happymacer
author_rank: Newbie
timestamp: August 18, 2025, 11:13:13 am
content: Hiya, this looks just like something I could use to test my transformers. Did you make any progress since posting?
diy fan controller - Page 1
Forum section: electronics / projects

author: odell
author_rank: Contributor
timestamp: December 03, 2011, 08:24:23 am
content: HiI'm working on a diy fan controller in isis professional. I test it and the fan speed goes up and down why is that and what can I do so the fan speed don't go up and down.

author: Simon
author_rank: Unknown
timestamp: December 03, 2011, 08:26:11 am
content: how does the controller work ? maybe it reacts too quickly so has to keep back tracking and going around in circles hunting for the right speed.

author: odell
author_rank: Contributor
timestamp: December 03, 2011, 08:32:12 am
content: It go's threw a Microcontroller a 80C58 then it go's to Transistor IRFZ44E then it send 12v to the fan

author: Simon
author_rank: Unknown
timestamp: December 03, 2011, 08:45:35 am
content: yes but what does the microcontrollers program do ? for example,startcheck tempif temp = highthen increase fan speed "X" amountend ifif temp = lowthen decrease fan speed by "X"end ifgoto startthat would cause the effect you mention, because the microcontroller is checking the temperature thousands of times a second, so before the temperatre gets a chance to change (due to the change air flow) you will be oscilating from one end of the range to the other. You need a time delay. If of course that is how you wrote your program

author: david77
author_rank: Frequent Contributor
timestamp: December 03, 2011, 08:52:42 am
content: Could it be that your fan blows directly onto your temp sensor or the part you want to cool?If so and if the oscillation (speed goes up and down) is realtively slow something like this might happen:Part to be cooled heats up -> fan controller increases voltage to fan -> fan blows harder on the part -> temperature goes down -> fan controller decreases voltage -> part heats up again -> fan controller increases fan speed ... and so on.This is called an underdamped control system I believe. Basically it's a feedback loop.

author: odell
author_rank: Contributor
timestamp: December 03, 2011, 08:58:18 am
content: QuoteI don't have it made. I'm test it on my pc

author: Simon
author_rank: Unknown
timestamp: December 03, 2011, 08:59:11 am
content: well then it comes down to your feedback loop, what does it do ? what does your code say ?

author: Zero999
author_rank: Super Contributor
timestamp: December 03, 2011, 10:14:17 am
content: Quote from: odell on December 03, 2011, 08:58:18 amHow are you simulating it?You really need to build it in real life to test it properly.

author: ejeffrey
author_rank: Super Contributor
timestamp: December 03, 2011, 10:19:24 am
content: Really, we just need a lot more information about what you are doing. You are using PWM? Are you just trying to run the fan at a specified but variable speed, or temperature control? Does your fan have a tachometer? At what level are you simulating?Remember the golden rule of simulation: garbage in, garbage out. If your model does not capture the important factors, the results will be meaningless. The results might be meaningless anyway, but without good input data they have no chance
diy fan controller - Page 1
Forum section: electronics / projects

author: odell
author_rank: Contributor
timestamp: January 09, 2012, 11:36:13 pm
content: I working on a diy fan controller what i need to know is if i use a transistors do i need 3 wires fans or 4 wires fans (pwm)

author: PeterG
author_rank: Frequent Contributor
timestamp: January 09, 2012, 11:55:52 pm
content: Hi, 2,3 and 4 wire fans can be controlled with PWM. A transistor/mosfet is used to switch the current.Regards

author: joelby
author_rank: Frequent Contributor
timestamp: January 09, 2012, 11:56:50 pm
content: It depends on the fan.If it's a three wire fan with a DC voltage input, tachometer output and ground, you'll need to use a switching transistor or similar to do PWM.If it's a four wire fan with some integrated electronics and a PWM pin, then you can probably drive it directly from a microcontroller with compatible voltage levels (this page has some good information:http://www.pavouk.org/hw/fan/en_fan4wire.html)Not all fans are the same though. Read your fan's data sheet.

author: IanB
author_rank: Super Contributor
timestamp: January 10, 2012, 12:03:50 am
content: Lots of information here:http://en.wikipedia.org/wiki/Computer_fanYou can do PWM on a 2 wire fan if you choose a suitably low PWM frequency and you don't need feedback speed control.

author: aokman
author_rank: Contributor
timestamp: January 10, 2012, 12:39:44 am
content: 3 wire fans have the RPM feedback signal. 4 wire fans have RPM feedback / PWM signal line to feed the internal fan logic.You can PWM control standard 2 wire fans of course however it can cause the fans to resonate with the frequency.If you use 4 wire PWM fans, you don't need any sort of switching circuit. All you need to do is feed a signal and the fan will do its own regulation depending on the brand and implementation. I've made a few from simple 555 timers and a trimmer on NIDEC fans.
DIY Flame Lamp That Looks Like Real Fire! 🔥 (Arduino Project) - Page 1
Forum section: electronics / projects

author: protolab
author_rank: Newbie
timestamp: March 25, 2025, 11:26:19 am
content: A realistic flame effect lamp! It has 14 different light modes, including a super cool fire animation that actually looks alive.I put together a full video showing the entire process—from soldering and wiring to programming and testing. If you're into DIY electronics, Arduino projects, or just love unique lighting builds, you might find it interesting!Would love to hear what you think—what’s the coolest DIY project you’ve worked on? And if you’re curious, you can check out the full build here and support it with a like! 💡🔥
DIY Flir Photon 320 30hz monocular - Page 1
Forum section: electronics / projects

author: ianspy1
author_rank: Newbie
timestamp: October 16, 2022, 07:48:07 am
content: Hello everyone !I am new to this forum, so I hope I dont make any mistakes.So, some time ago I scored a very good deal on the photon and slowly started to figure out how to build this thing. My experience with CAD so far is only Tinkercad, so it took some time.First my Plan was to use a small LCD screen with a lens in front of it. But to make it more compact I went with a 640x480 viewfinder from aliexpress.Next up I tried to get a arduino to send serial commands into the core to change stuff like zoom, color pallet etc. This turned out to be extremely complicated. Thankfully "Kmphoenix" already built a controller for this core ! I added 4 buttons onto the case that lead to the controller.I also got a dual switch to be able to just turn off the screen, so I could keep the core drawing power from my power bank when stowed up.After I tested that it would fit aswell as testing that it works. I gave it 3 coats of "MGchemicals 422C" to make it somewhat waterproof as well as setting buttons, viewfinder, switch, xt60 connector in super glue.To make it mountable to a L4G24 mount (clone) I also remixed the J-arm by "drunknape". This way I can swipe it up and when folded up it folds closer to the helmet for better storage. Also I bought a PVS-15 dovetail since I was concerned about the weight on the 3D printed dovetail.Here´s the project on thingieverse with all the links:https://www.thingiverse.com/thing:5472142And here is the remixed J-arm:https://www.thingiverse.com/thing:5559945Oh also enjoy the fine paint art xD
DIY: Fluke SV225 Stray(ghost) Voltage Adapter - Page 1
Forum section: electronics / projects

author: diy_guy
author_rank: Newbie
timestamp: May 13, 2014, 02:11:34 am
content: This seems like a great product, but to amazon it north of the border it would cost +$100 + shipping - yikes!I read this for a diy project but dont know where to start. Diagrams help.http://www.electriciantalk.com/f14/fluke-stray-voltage-eliminator-25070/

author: David_AVD
author_rank: Super Contributor
timestamp: May 13, 2014, 02:19:26 am
content: Interestingly the data sheet says 3K impedance, but "Voltages up to 1000 volts continuous can be safely applied to the Adapter without damage".Wonder what's inside?

author: diy_guy
author_rank: Newbie
timestamp: May 13, 2014, 02:41:24 am
content: maybe someone can "take it apart"

author: gaijin
author_rank: Contributor
timestamp: May 13, 2014, 03:13:43 am
content: Quote from: David_AVD on May 13, 2014, 02:19:26 amMy guess a 3k resistor.

author: David_AVD
author_rank: Super Contributor
timestamp: May 13, 2014, 03:26:46 am
content: Quote from: gaijin on May 13, 2014, 03:13:43 amBut if you put a 3K resistor across 1000V the power dissipation would be huge.

author: gaijin
author_rank: Contributor
timestamp: May 13, 2014, 03:58:56 am
content: PTC inline with a resistor, these adapters are not for continuous use.

author: David_AVD
author_rank: Super Contributor
timestamp: May 13, 2014, 09:09:14 am
content: That was my guess too. The max voltage would be rather less than 1000V, but I didn't read the whole manual to see what it was.

author: diy_guy
author_rank: Newbie
timestamp: May 14, 2014, 12:37:11 am
content: Quote from: diy_guy on May 13, 2014, 02:41:24 am...so I can learn to make my own and save +$100.00. Anyone do a "take it apart" vid?

author: jaslies
author_rank: Newbie
timestamp: July 26, 2016, 04:09:58 pm
content: Hey everyone,I'd like to make one too! It would be cool if someone took one apart and showcased the components. Or at least make a resistance measurement.Kind regards!

author: Monkeh
author_rank: Super Contributor
timestamp: July 26, 2016, 05:21:52 pm
content: Quote from: David_AVD on May 13, 2014, 09:09:14 amWhy? There are PTCs rated to quite high voltages, and many of them have nominal resistances around 1k - three of those in series, you've got your ~3k load which is tolerant to high voltages.

author: aqibi2000
author_rank: Regular Contributor
timestamp: September 21, 2020, 10:42:30 am
content: Did anybody get around to building this?
DIY FM Receiver - Page 1
Forum section: electronics / projects

author: kvd
author_rank: Contributor
timestamp: December 08, 2020, 08:07:30 pm
content: Hi fellow electrons!I just finished uploading my self-designed and homebuilt FM receiver project to Github. It contains schematics, pcb layout and documentation. On Youtube you can find a short demo of the receiver.Github:https://github.com/kvdijken/FM-ReceiverYoutube:https://www.youtube.com/watch?v=TlIiLwKdwg0&feature=youtu.beHope this is of interest to you!Koen

author: kvd
author_rank: Contributor
timestamp: December 10, 2020, 09:06:30 pm
content: The Github project's visibility was still at private.I changed it to public. It should be visible to anyone now.

author: mag_therm
author_rank: Frequent Contributor
timestamp: December 10, 2020, 11:04:29 pm
content: Can access now, thanks.Can I open the circuit diagrams in qucs? Has same .sch. ......Edit: Ans No, wrong file typeHow does the detector handle a weak station close to a strong one?I have an old mono tube type FM radio restored here, it would be interesting to compare performance.

author: JCK
author_rank: Contributor
timestamp: December 11, 2020, 06:12:17 pm
content: Nice project. Is there a bill of materials anywhere?
DIY GPIB connector made from parallel printer cable - Page 1
Forum section: electronics / projects

author: soren
author_rank: Regular Contributor
timestamp: September 23, 2013, 04:51:35 pm
content: What do you do when you want to play with having a microcontroller talk GPIB to test equipment, but don't have a GPIB connector?You just make one of course!(Looks like they are getting harder and harder to buy anyway.)The formerly common parallel printer connector is a 36-pin version of the same connector type and many such cables are lying around unused, often with the metal-bodied Amphenol housing, which can be disassembled.I ground away the excess plastic with a Dremel router bit. One tip is to remove or bend away the unnecessary pins before attacking the plastic so the tool won't catch on them.Et voilà!

author: Unknown
author_rank: Unknown
timestamp: September 23, 2013, 05:14:38 pm
content: Neat hack, and used parallel printer cables are a lot more common and cheaper on the used market (you can probably find them for free without much effort). You used an unshielded cable, so interference might be an issue under some circumstances.

author: jancumps
author_rank: Unknown
timestamp: September 23, 2013, 05:20:43 pm
content: I nicked a parallel printer cable for the same reason just to find out it was smaller than the connector at the back of my scope.
DIY Ground Tips - Page 1
Forum section: electronics / projects

author: Jon86
author_rank: Frequent Contributor
timestamp: January 06, 2014, 08:15:20 pm
content: I've been wondering, what's the best way to make a probe ground tip and what kind of wire should you use? I tried regular breadboard hookup wire twisted round the end of the probe, but it's not springy enough and has a tendency to slip across connections.

author: robrenz
author_rank: Super Contributor
timestamp: January 06, 2014, 08:46:47 pm
content: Music wire, piano wire, guitar string. Anything that is spring tempered wire will work. you will have to use a much smaller diameter mandrel than the probe because it will have a lot of springback. you will just have to experiment. You can use the shank of drills for your mandrels.

author: Jon86
author_rank: Frequent Contributor
timestamp: January 06, 2014, 09:18:54 pm
content: Quote from: robrenz on January 06, 2014, 08:46:47 pmGreat, thanks.

author: don.r
author_rank: Frequent Contributor
timestamp: January 06, 2014, 09:20:23 pm
content: Old springs. I have a whole drawer of them.

author: Andy Watson
author_rank: Super Contributor
timestamp: January 06, 2014, 09:23:49 pm
content: Paper clip.

author: Jon86
author_rank: Frequent Contributor
timestamp: January 06, 2014, 09:24:38 pm
content: Quote from: Andy Watson on January 06, 2014, 09:23:49 pmI can't see that working, they're hardly springy...

author: Andy Watson
author_rank: Super Contributor
timestamp: January 06, 2014, 09:31:57 pm
content: Quote from: Jon86 on January 06, 2014, 09:24:38 pmWorks for me. Use a drill bit one size smaller than the ring section of the probe as a mandrel. Wind a few turns, bend the remainder to make a dog-leg towards the probe tip, fit to probe and chop to length with angled cutters. The last operation leaves a nice sharp tip on the paper clip for piercing gunge and grot on the ground plane.

author: AndrejaKo
author_rank: Frequent Contributor
timestamp: January 07, 2014, 11:47:59 pm
content: Quote from: Jon86 on January 06, 2014, 08:15:20 pmI can't believe one of my pictures became famous on the Internet!Anyway, to add to the discussion, one type of wire I sometimes use when I can't find those ground springs (or when I need a custom size) is solid CAT5 or 6 Ethernet cable. Such cables are very cheap, have 8 conductors in a single cable and aren't too difficult to work with.The downsides are that experimentation may be needed to find one type which mechanically feels good enough and that they usually aren't very springy. On the other hand, I usually use them when I already have a suitable hole for the spring or when I can tie it around end of a through-hole component lead. In the latter case, the lack of springiness can actually be a bonus, since it's easy to wrap the wire around the component.
DIY high performance solder fume extractor - Page 1
Forum section: electronics / projects

author: nexus
author_rank: Regular Contributor
timestamp: March 07, 2021, 08:45:32 pm
content: Hi all,I just wrapped up a pretty involved mechanical and electrical design effort to make what I consider an "ideal" fume extractor based on my needs and desires.Design files for the electrical portion (fan controller) are available for anyone interested in such a standalone doodad:https://neonkev.com/2021/03/07/diy-high-performance-solder-fume-extractor/Enjoy!Kevin

author: MikeK
author_rank: Super Contributor
timestamp: March 07, 2021, 09:31:19 pm
content: Probably not enough flow to be high performance. Watch this:

author: nexus
author_rank: Regular Contributor
timestamp: March 07, 2021, 10:38:50 pm
content: Quote from: MikeK on March 07, 2021, 09:31:19 pmI did a quick ebay search on the fan unit he used:https://www.ebay.co.uk/itm/143433867928The description says "Airflow up to 187 m3/hour"In comparison, the fan I used is the San Ace 9LG1412P5G001, which is rated at 9.0 m3/min, or 540 m3/hour.The 9LG1412P5G001 is a 140x51mm metal framed, 62 watt fan capable of 318 CFM and 655 pa of static pressure. Do not confuse it with a measly computer fan:

author: archil
author_rank: Contributor
timestamp: March 16, 2021, 10:42:20 am
content: nice stuff.

author: ElektroHS
author_rank: Contributor
timestamp: March 16, 2021, 01:19:04 pm
content: That's interesting project, but I didn't calculate your BOM. If I understood correctly from your article - the price of such fume extractor about $500? thx

author: MikeK
author_rank: Super Contributor
timestamp: March 16, 2021, 01:48:27 pm
content: So the fumes are being sucked up at high speed...And then put back into the room?

author: ElektroHS
author_rank: Contributor
timestamp: March 16, 2021, 03:39:46 pm
content: There is hepa + carbon filters

author: ElektroHS
author_rank: Contributor
timestamp: March 16, 2021, 03:43:17 pm
content: Many of fume extract filters don't take "dirty air" to outdoor. Sometimes you don't have even possibility to arrange it. Therefore you will have just one solution - filters. Expensive fume extractors for $1K and over - don't take it outdoor too... it's just process "dirty air" through set of filters.I can understand the solution, but the question about price... if it costs about $500, then it worth to think about "factory extractor"
DIY Home Alarm Monitoring - Page 1
Forum section: electronics / projects

author: ludzinc
author_rank: Unknown
timestamp: April 10, 2013, 04:06:48 pm
content: Inspired by Liors Alarmino project:http://ludzinc.blogspot.com.au/2013/04/cutting-out-middle-man.html?m=1Any thoughts / comments / errors found will be gratefully accepted! I'm yet to order the PCBs so there's time to fix SNAFUs.
DIY Home Automation - ESP32, Raspberry Pi || IoT Project - Page 1
Forum section: electronics / projects

author: dusnoki
author_rank: Newbie
timestamp: November 28, 2018, 08:52:23 pm
content: Check out my first attempt at a DIY Home Automation project.With this small box I could control my tv, led strip, sound system and lights. It would also monitor the inside humidity and temperature as well as get real time data from an external API for the outside humidity and temperature and display them nicely in a graph. I even save all these values to a local database and display those values in a chart based on the date I choose.Hope you guys like it
DIY Hot Air Station - Page 1
Forum section: electronics / projects

author: fable
author_rank: Regular Contributor
timestamp: June 08, 2025, 01:20:19 pm
content: Hello everyone,I want to share with you a hot air station controller that I’ve been working on for quite some time. Originally, I just wanted to make a replacement PCB for cheap Chinese stations like the Gordak 850, since the heater control in those is, frankly, terrible. It took over 4–5 minutes to reach target temperature, and without any feedback, the temperature kept drifting. Changing airflow would also change the temperature, and you couldn’t even know what temp you set—just some vague number from 1 to 8.All of that frustration pushed me to build my own controller board from scratch.1602 LCD displaySaves all settings on power-offStandby mode (originally activated by placing the handle on the holder, but I switched to a handle button)Boost button on the handle: while held, target temp ramps upHeater won’t turn on unless blower is running (safety)Two rotary encoders with push buttons – one for airflow, one for temperature (also used for menu navigation)Menu with LCD brightness and contrast adjustmentPressing both encoders resets all settings to defaults4 memory presets (accessed by pressing the right encoder on the main screen)Relay cuts power to the heater if the actual temp exceeds the target by more than 50 °CBuzzer alarm for overtempIntuitive memory preset selection using the right encoder (press to enter, turn to select, press to confirm or press left encoder to cancel)At some point I realized—I already had the PCB design done, so why not build the entire hot air station myself? The only missing part was the blower. After lots of trial and error, I designed a blower variant similar to those in stations like Quick 861, BST863, and ATEN ST862. I ended up designing a 3D model and 3D printing my own.For the motor, I repurposed one from an old 3.5" HDD. To drive it, I spent a fair amount of time searching IC and finally found a simple solution using the 4949GT driver IC. While I didn’t take any formal airflow measurements, I can say it’s noticeably more powerful than the Gordak 850.The MCU is a PIC18F46K22—mainly because I have a lot of them lying around. The firmware is written in MikroC for PIC. I’ll be honest: I’m self-taught and the code is a tangled mess, but it works!What's Next:I have two working prototypes and plan to open-source the project (hardware and firmware) once I finish a new, cleaner PCB design—current ones are single-sided with too many bodges.Until then, I’m open to suggestions and ideas. I'd love to hear feedback from you.

author: thm_w
author_rank: Super Contributor
timestamp: June 10, 2025, 12:43:43 am
content: Was going to say this is pointless if you keep the original pump, but you didn't you replaced it, nice work.Any idea what sort of power draw the motor is at max?Looks like the IC isA49491.6A peak

author: fable
author_rank: Regular Contributor
timestamp: June 10, 2025, 04:17:50 pm
content: Thanks for the feedback! Yeah, the stock pump was big, noisy, and vibrated a lot, so I went with the HDD motor. At max speed, it draws around 750 mA at 16V.
Diy Hot Plate - Page 1
Forum section: electronics / projects

author: Arcamax123
author_rank: Contributor
timestamp: June 23, 2016, 04:22:13 am
content: I am planning on making a hot plate with a chunk of aluminium on top... I would like some ideas on how to do this.

author: Arcamax123
author_rank: Contributor
timestamp: June 23, 2016, 04:38:52 am
content: Quote from: wilfred on June 23, 2016, 04:30:23 amWell I guess it doesn't need to be aluminium. I want to stick something on top to heat things up with... a lower temperature, 6 or 7inch square maybe. Need options lol

author: nali
author_rank: Frequent Contributor
timestamp: June 23, 2016, 06:26:05 am
content: There are tons of heated beds available for 3D printers about that size, try searching Reprap heated bed.

author: ion
author_rank: Regular Contributor
timestamp: June 23, 2016, 08:09:35 am
content: I made a one like this last year - I used aluminium to make the machining easier with the limited tools I have.The exact design will depend on what you want to do with it, but you can make a basic hotplate using the aluminium, cartridge heaters and a PID temperature controller. If you use mains powered heaters make sure you earth the hotplate and use a fuse too.

author: Ian.M
author_rank: Super Contributor
timestamp: June 23, 2016, 08:52:41 am
content: Its slightly bigger than you want, but you'd have to put in a lot of work to beat something like:https://www.amazon.com/Presto-07211-Liddle-Griddle/dp/B00006IUWL

author: Arcamax123
author_rank: Contributor
timestamp: June 23, 2016, 09:57:41 pm
content: I wonder... can I use an old stove top element some how?

author: uncle_bob
author_rank: Unknown
timestamp: June 24, 2016, 12:35:24 am
content: Quote from: Arcamax123 on June 23, 2016, 09:57:41 pmHiYou can buy hot plates on eBay or Craigs List for next to nothing at all. Unless you already have a pile of parts ready to go, $10 or $20 spent there is the best bet. What does your design need to do that the used commercial unit does not do?Bob
DIY Huntron circuit variation--- schematic check - Page 1
Forum section: electronics / projects

author: Analogologist
author_rank: Newbie
timestamp: March 20, 2025, 05:16:16 am
content: Hello everyone,New guy here and I'm relatively new to fooling with AC circuits. 95% of my electronics exp. is working with low voltage DC (3v - 24V) analog and IC circuits with a bit of microcontroller stuff So it's a kinda learn as you go for me right now.Want to build an "in circuit" Huntron style X-Y curve tracer. I've read what I could find on the subject and seen quite a few diy and minimalist versions but some of the little things are often not mentioned. I wanted one with the functions that I want and to make sure I patterned it out right. So if someone could have a look with more experienced eyes that mine for errors I would greatly appreciate it.

author: bostonman
author_rank: Super Contributor
timestamp: March 21, 2025, 01:36:49 am
content: Is that 5V regulator going to handle the constant switching or will it shut down when the voltage is pulled low?

author: Analogologist
author_rank: Newbie
timestamp: March 21, 2025, 03:10:58 am
content: I set it up as an option for 6.3v supply. So yes it's set up for constant supply to prevent any possible regulator lag. No good that way ?

author: bostonman
author_rank: Super Contributor
timestamp: March 21, 2025, 03:27:33 am
content: You don't state how fast the 555 is turning on/off.Nor do you state what type of regulator or the relay coil current.Assuming the relay coil is 30ohms, the regulator is almost 0.25W. Also, is that a LDO regulator because it's only a 1V delta.As for the overall schematic, I'm uncertain what this is exactly doing. You have a relay getting turned on and off by a 555 timer which would induce ringing, and then providing 6V at fairly high current to the BNCs.

author: Analogologist
author_rank: Newbie
timestamp: March 21, 2025, 04:08:55 am
content: 555 is roughly 1sec on 1 sec offregulator is not LDOrelay is 30mA coil 167 ohm resistance max switching 60v max current 1Athe BNC side of the schematic is set to provide 1v and around 1.2mA to the BNC's. The timing circuit is just switching between 2 separate probes. The transformer coil is only putting out 500mA on that circuit. I don't see the problem???

author: IconicPCB
author_rank: Super Contributor
timestamp: March 21, 2025, 04:21:33 am
content: Your neon lamp should have some resistance in series .Indeed what is the relay doing?

author: Analogologist
author_rank: Newbie
timestamp: March 21, 2025, 04:56:43 am
content: it is simply switching from one red probe to another automatically for circuit comparison. Which is pretty much what the original Huntron did.
DIY impregnation for ETD39 flyback transformer windings - Page 1
Forum section: electronics / projects

author: fpospisil
author_rank: Newbie
timestamp: April 22, 2025, 05:57:58 pm
content: Hello,I'm building a transformer for a flyback converter using an ETD39 core. I sprayed each winding with PCB lacquer, but at light load and low switching frequencies, the transformer makes an audible whining noise.Does anyone have experience with better materials or methods for impregnating or potting the windings in a home workshop to eliminate this kind of noise?Thanks in advance for your help!

author: uer166
author_rank: Super Contributor
timestamp: April 22, 2025, 07:56:34 pm
content: It's almost always not the windings but magnetostriction of the core. Did you glue the core together and potted everything? Or just the windings.

author: David Hess
author_rank: Super Contributor
timestamp: April 22, 2025, 09:09:36 pm
content: I would not do anything less than vacuum potting, which can be done inexpensively. I think anything else would be a waste of time.

author: incf
author_rank: Frequent Contributor
timestamp: April 22, 2025, 09:25:21 pm
content: A vacuum chamber and pump can be bought relatively inexpensively online (~$100 US IIRC).I'd go that route.

author: Langdon
author_rank: Frequent Contributor
timestamp: April 22, 2025, 09:33:32 pm
content: Why not just buy a transformer?

author: uer166
author_rank: Super Contributor
timestamp: April 23, 2025, 01:09:04 am
content: Quote from: Langdon on April 22, 2025, 09:33:32 pmFlyback SMPS transformer is almost never OTS, I understand where OP is coming from.

author: fpospisil
author_rank: Newbie
timestamp: April 23, 2025, 06:43:51 pm
content: Quote from: Langdon on April 22, 2025, 09:33:32 pmI can't buy a mass-produced transformer because I designed the PCB for my transformer. I used the UCC28600 controller for the first time. I didn't expect it to be able to change the operating frequency in such a large range and there would be noise problems.

author: fpospisil
author_rank: Newbie
timestamp: April 23, 2025, 06:47:22 pm
content: Quote from: incf on April 22, 2025, 09:25:21 pmthanks for the reply, I will go the vacuum impregnation route.

author: fpospisil
author_rank: Newbie
timestamp: April 23, 2025, 06:49:23 pm
content: Quote from: uer166 on April 22, 2025, 07:56:34 pmI glued the core with two-component epoxy glue. The noise is quite weak, I don't know exactly which part of the transformer is making it.

author: Langdon
author_rank: Frequent Contributor
timestamp: April 24, 2025, 04:06:07 pm
content: Neutral-cure silicone might be the answer (as it so often is).Just slather it all over the transformer and nothing should vibrate.
DIY Induction loop car detector - Page 1
Forum section: electronics / projects

author: dog80
author_rank: Regular Contributor
timestamp: September 02, 2013, 02:54:36 pm
content: I want to build an induction loop system that will sound a buzzer whenever a car passes over the loop.I've seen the documentation of such a system and apparenty the circuit resonates at a frequency of around 25-30 KHz Whenever a big enough chunk of metal passes over the loop it will cause the resonant frequency to increase a few KHz. The system monitors the frequency and whenever it detects a rise it assumes that a car has passed and will do the desired action.I have absolutely no idea on how to build this.What type of wire should I use for the loop and how many turns?Any ideas on how to implement the frequency detector?

author: kayvee
author_rank: Regular Contributor
timestamp: September 02, 2013, 03:23:25 pm
content: Front end consists of a Colpitts oscillator where your roadway loop forms the inductive component.A 2 X 1 m loop with 3 turns of wire is a good size.Expect a lot less than a few KHz change with a typical vehicle passing, more like 50 to 500Hz change typically.0.01 to 0.02% delta L/L is normally the maximum sensitivity of a loop detector.

author: dfmischler
author_rank: Frequent Contributor
timestamp: September 02, 2013, 03:24:49 pm
content: Start here:Traffic Detector HandbookIn practice, real world detector loops are self-tuning (perhaps with a PLL). This is necessary because temperature affects the inductance and capacitance of the components. So eventually, the presence detected will be tuned out. Ideally, a very gradual change in loop frequency will just be accommodated without ever indicating a presence.You might find that you can get a commercially built loop detector on ebay for a low price.Other interesting links:How Loop Detectors Workhttp://www.dkaccess.com/English/Gate_Operators/Loop_Info-P-3-10.pdf?

author: traxonja
author_rank: Newbie
timestamp: February 28, 2014, 12:37:53 pm
content: Hi,I know this is an old thread, but here is a DIY version of Inductive Loop Vehicle Detector built around PIC microcontroller:http://www.elektronika.ba/843/inductive-loop-vehicle-detector-v2-1/You can put a buzzer to relay output or even remove the relay and power your buzzer directly from a transistor.Regards!
DIY Instek GSO-810 Replacement Handle - Page 1
Forum section: electronics / projects

author: cliffyk
author_rank: Frequent Contributor
timestamp: January 09, 2022, 01:31:18 am
content: AS has happened with many of the older Instek instruments from the mid-late 90s (spectrum analyzers, oscilloscopes and other) that shared the same cabinet configuration, the plastic handle on my GSP_810 failed when it became brittle and the locating pins on the hubs sheared, and the hubs themselves cracked and fell apart.However t'other day it occurred to me that I could use FreeCAD to design new hubs in such a manner that a length of aluminum flat stock could be fastened to a couple of the same to make a new handle. I got the design finished yesterday and 3D printed a prototype for final fitting last night. After a few tweaks of the design I have produced two hubs (see below for a couple "screen grabs" from FreeCAD:(inner side showing the central post and 12 locating pins)(outer side showing the slot for mounting the handle to fabricated of ¾ x ⅛ aluminum flat stock to be fastened with small sheet metal screws)I plan to reinforce the long span of the flat stock handle by laminating a couple of ¾ x ⅜ oak "pads" to it.I will update this post when it is done.If anyone wants either the FreeCAD design or .stl model files give me a yell and i will post links to same.Here is a screen shot of a pair of the hubs, with supports, and ready for slicing created using theChitubox3D model manipulation and "slicing" application:I use an Elegoo Mars (upgraded to a Mars Pro) printer, and a 50/50 mix of WeistekTenaciousresin (clear) and theirStandardresin (gray) to obtain the desired detail and mechanical characteristics. TheTenacioushas an elongation-at-break of 50% or better, theStandardEoB is 11-20%. Both are are the best I have found and reasonably priced too.Here's a photo of the two hubs printed, fully cured, and cleaned up (I am going to paint them in ivory to match the cabinet):
DIY interpolating reciprocal frequency counter FC-510 - Page 1
Forum section: electronics / projects

author: Liv
author_rank: Regular Contributor
timestamp: March 05, 2015, 01:27:03 pm
content: Interpolating reciprocal frequency counter FC-510Features:• reciprocal counting + interpolation (3-rd generation by Pendulum classification)• main input frequency range: 0.1 Hz…100 MHz• period range : 10 ns…10 s• measured single pulse duration: 100 ns…10 s• measured duty cycle : 0.0000001…0.9999999• measured RPM: 6…999999 rpm.• measuring interval: 1 ms…10 s• analog interpolator resolution: 1 ns• average count: 1…100• IF range: ±99.9999 MHz• math: Fmin, Fmax, dF• hold: yes• programmed prescaler ratio: 1…1000• prescaler frequency range: up to 2 GHz• input impedance: 1 MOhm || 30 pF• input coupling: DC+AC, AC• input attenuator: 1:1, 1:10• sensitivity: 100 mV (up to 50 MHz)• max input voltage: ±50 V• comparator threshold: –0.5…+0.5 V; –5…+5 V• optional LPF: 100 kHz• reference: TCXO, ±2.5 ppm (-20…+70°C)

author: Liv
author_rank: Regular Contributor
timestamp: March 05, 2015, 01:29:18 pm
content: Some photos:

author: DmitryL
author_rank: Regular Contributor
timestamp: March 05, 2015, 01:45:12 pm
content: +1. I made this frequency meter about a year ago. Works like a charm.For clocking I used a standard 10Mhz VTCXO with a trimmer resistor for fine freq. adjustment. Calibrated all thing by 1PPS from a GPS receiver.

author: Liv
author_rank: Regular Contributor
timestamp: March 05, 2015, 04:03:39 pm
content: Firmware version 2.x supports 9-digit frequency display (for 1601 and 1602 LCDs) and level meter in second line (for 1602).Resolution demonstration (sorry for unintelligible language, I will try to fix):

author: DmitryL
author_rank: Regular Contributor
timestamp: March 05, 2015, 04:42:13 pm
content: BTW, you forgot to mention that it is a _reciprocal_ counter, not a direct count one.It makes a huge difference from specs perspective.

author: Liv
author_rank: Regular Contributor
timestamp: March 05, 2015, 05:02:36 pm
content: Thank you, I made correction of features list.

author: DmitryL
author_rank: Regular Contributor
timestamp: March 05, 2015, 05:06:16 pm
content: Don't forget the topic name, it must be eye-catching!

author: Liv
author_rank: Regular Contributor
timestamp: March 05, 2015, 05:13:42 pm
content: OK, fixed.
DIY inverter battery tab spot welder - Page 1
Forum section: electronics / projects

author: Refrigerator
author_rank: Super Contributor
timestamp: May 20, 2023, 06:30:05 pm
content: I had the crazy idea to build an inverter battery tab spot welder.First test was just hooking up an old ATX PSU to a custom transformer, which yielded some results.Even managed to make a couple spot welds before the half bridge blew out.Then built a two switch forward converter and a more calculated transformer but started noticing problems.First problem was that any tangible current output would only be available right at the transformer, but at the end of the welding leads i would get basically nothing.Seemed perhaps that my output voltage was too low and could not overcome the total resistance in the loop.Next i had to consider the inductance of the leads and found that they attenuate my output massively.Please keep note that the output is not rectified. The EMI from this thing must be nuts, but i digress.Now i have ordered some IGBT's to build a proper power stage that can handle at least 4kW.From my estimations my output leads can have a minimum of 100nH inductance and 400nH max, so i'll have to keep my cables tightly paired together to minimize the loop area.Tbh i'm not sure how practical this project is but it's a fun exercise (in futility perhaps).What do you guys think about this?Also i'd like to build a low-ish frequency inverter that uses laminated EI core instead of ferrite.I'm thinking 1kHz should be an ok-ish switching frequency to test things out. Imagine the noise this thing would make.

author: Decapitator
author_rank: Contributor
timestamp: June 11, 2023, 05:31:28 am
content: You are overthinking this. Look into building a "capacitor discharge welder". There are plenty of ideas on YouTube to start with. There also exists a two part article that was originally published in the March and April of 2022 issues of Silicon Chip magazine. The same article was republished a year later in Practical Electronics (EPE) magazine. I consider the project described in that article to be overkill for spot welding thin nickel tabs to 18650 cells without burning holes through either, but the basic approach is sound.

author: tautech
author_rank: Super Contributor
timestamp: June 11, 2023, 07:50:12 am
content: https://www.eevblog.com/forum/projects/guesses-on-what-i-am-attempting-here/
DIY JBC clone soldering station wiring mistake -- 5A through thermocouple! - Page 1
Forum section: electronics / projects

author: microbug
author_rank: Frequent Contributor
timestamp: January 18, 2024, 10:41:35 pm
content: So, I made a mistake. I designed and built a whole JBC-compatible C245 soldering station but I got the wiring wrong.The 'correct' way to do this (I guess) is to connect the heater (blue wire) to a MOSFET-switched 24V supply, the common (red) wire to circuit GND, and the thermocouple/earth to a thermocouple amp IC or inverting op-amp. The thermocouple has a pretty low resistance so the tip is still ESD safe.What I did is connect the heater as above, common (red) wire to a non-inverting amp, and thermocouple/earth to GND. So when the heater is on, its current flows through the thermocouple and to GND. When the heater is off the thermocouple can be read fine.I'm wondering what I can do to salvage this, or if it needs fixing at all. I did breadboard it like this, and nothing blew up -- the iron got hot and solder melted, and it regulated just fine. However, I don't know if the thermocouple wire can handle this kind of current in the long term.Does anyone have any suggestions on how to get this working? I think the easiest way to rewire would be to swap the GND and TC pins and make the op-amp negative feedback -- is there an easier way I'm missing?C245 pinout below:

author: shangaoren
author_rank: Regular Contributor
timestamp: January 19, 2024, 10:17:42 am
content: If my memory is good some sorts of JBC tips have the current flowing through thermocouple and even in the JBC C245 the current is flowing through thermocouple

author: microbug
author_rank: Frequent Contributor
timestamp: January 19, 2024, 10:33:22 am
content: Thanks, it does seem that way from checking other people’s designs and the reverse engineered JBC schematic. I’ll give it a go as is

author: SiliconWizard
author_rank: Super Contributor
timestamp: January 19, 2024, 10:20:23 pm
content: You can find the tip construction detailed in JBC patents. Yes, thermocouples are in series with the heating element and are an integral part of the tip, they can withstand the current without any problem.Note that you must be careful about the potential that will be connected to the outer shell of the tip relative to "earth", as it could damage whatever you're soldering, so unless your design is fully isolated (floating), and the tip connected to earth via some resistance, you don't want to have any other potential than GND connected to the outer shell. The outer shell of the tip is connected to pin 1 of the RPC connector, on all JBC tips (C210, C245...) AFAIR.Check the pinout of the connector, it's marked inside of it. I'm assuming your image is "correct", but it doesn't show any pin number, nor whether this is a "top" or "bottom" view of the connector, so just check.