Show me some cool stuff you've made! - Page 1
Forum section: electronics / general

author: strangersound
author_rank: Regular Contributor
timestamp: January 23, 2017, 01:01:38 am
content: Show me some cool stuff you've made or built. Electronics, furniture, lego sets, out buildings, woodworking, knitting, a cake, computers, skateboards, whatever...if you made it, I want to see it.

author: TiN
author_rank: Super Contributor
timestamp: January 23, 2017, 04:34:02 am
content: LED cookies.Simple POV for bike

author: Nystemy
author_rank: Contributor
timestamp: January 24, 2017, 05:26:05 am
content: I recently made a small transformer to bring some life back into an old HP 3478A. Just some 1400 turns of wire on it... And probably another 4000 turns of kapton tape.I learned one big thing, and that is to just buy a set of transformers next time, though, it were a bit of fun.

author: Melt-O-Tronic
author_rank: Frequent Contributor
timestamp: January 24, 2017, 06:02:31 am
content: How about a distribution amplifier for my GPSDO project? It's major overkill for only 10 MHz, but that's how I learn.I machined the housing from aluminum bar stock. Power comes in through a feedthrough cap and the coax leads pass between layers of RF gasketing. Stainless steel springs put 4.5 lbs of pressure on the corners of the board to keep it seated against the housing which is chromate passivated to prevent corrosion and ensure surface conductivity.

author: Nystemy
author_rank: Contributor
timestamp: January 24, 2017, 06:16:29 am
content: Quote from: Melt-O-Tronic on January 24, 2017, 06:02:31 amLooking really neat, and nice attention to details.

author: capt bullshot
author_rank: Super Contributor
timestamp: January 24, 2017, 06:31:48 am
content: Hand made PCB carving:Part of a big mess of wires:This thing charges a lithium battery pack from a solar panel, and discharges the battery into a 19V DC rail at my home (intended to save power for some standby power devices like internet router etc.). See the whole thing here:http://wunderkis.de/pvbat/It's running for 1 1/2 years now without any breakdowns or other problems

author: Fortran
author_rank: Regular Contributor
timestamp: January 24, 2017, 06:35:25 am
content: I've made a coffee monitoring system for workIt uses a HX711 to weigh the thermos and uploads to our intranet via ESP8266.Currently on display in my testbed. I haven't had time to create the new base for the coffee-machine yet.

author: andtfoot
author_rank: Unknown
timestamp: January 24, 2017, 07:19:24 am
content: My most recent project out of the garage...Inlay and some box modification done on CNC router.

author: vk3yedotcom
author_rank: Frequent Contributor
timestamp: January 24, 2017, 08:04:16 am
content: Hand-powered radio transmitter built inside a wind up torch (with 700km range)

author: tatus1969
author_rank: Super Contributor
timestamp: January 24, 2017, 09:10:38 am
content: last Saturday we had fun with our electric karthttps://youtu.be/nHTK5UELQGQp.s. turn on the sound while watching the video, or you'll miss the best part - us laughing

author: strangersound
author_rank: Regular Contributor
timestamp: January 24, 2017, 10:21:51 am
content: Yeah! Great stuff, folks. Thanks, I love enjoying seeing the arts of various disciplines. Industrial arts being a favorite, these are all good. I love a variety...nice range of stuff in a few posts, as well.

author: jaromir
author_rank: Unknown
timestamp: January 24, 2017, 11:16:01 am
content: I made some really cool tech stuff last week - one of my measurement devices went into climatic test up to -50 degrees of Celsius. Can't show you photos, though.

author: android
author_rank: Regular Contributor
timestamp: January 24, 2017, 11:17:33 am
content: A storybox (a music box that tells stories) for my 4yo grand-niece. One story per programmable mouse....and I put a "secret" message on the box just in case she ever becomes an engineer (even her parents don't know about that)The last pic is what's inside each mouse - a 128 Mb serial EEPROM. Should last about 40 years.

author: VK5RC
author_rank: Unknown
timestamp: January 24, 2017, 11:37:49 am
content: In preparation for the world's slowest attempt for EME - [bouncing a radio signal from Earth to Moon back to Earth] ( I've been at it for 3 years or so! - I keep getting distracted) I built and tested a low noise pre-amp for 1296MHz with about 37dB gain with about 0.6dB Noise Factor. Below are photos of the "real" test - cold sky to sun RF noise measurement.1 The feedhorn and pre-amp (and a little multi-pole band pass filter)2 The RF noise (red line ) of cold sky (lowest/first) section, (the dish pointing straight up), the middle section pointing at a tree, and the third section pointing at the sun.I was reasonably happy as I was within a dB or so of calculated sky-sun noise ratio.PS The drift down of the sun noise is the sun moving out of the focal point of the dish.

author: Kevman
author_rank: Regular Contributor
timestamp: January 24, 2017, 02:53:00 pm
content: This is probably the coolest thing I've personally built. People seem to really dig it when I run it at Demoparties.

author: cgroen
author_rank: Unknown
timestamp: January 24, 2017, 03:06:47 pm
content: Quote from: VK5RC on January 24, 2017, 11:37:49 amVery nice, brings back memories

author: RoGeorge
author_rank: Super Contributor
timestamp: January 24, 2017, 03:10:52 pm
content: https://hackaday.io/project/1411-xor-hobby-a-vintage-z80-computer-prototype

author: Fortran
author_rank: Regular Contributor
timestamp: January 24, 2017, 03:40:06 pm
content: I've got another one. Our wedding invitation0.6mm PCB in size A6, white soldermask, ENIG.Vertical USB and warm-white LED's on the back acting as a stand and power to back-light.Our guests loved them, even though few were geeks

author: tszaboo
author_rank: Super Contributor
timestamp: January 24, 2017, 03:46:56 pm
content: 4000A 300ppm accurate current source or sink.Well, it was a group effort. At work. The previous one.

author: Melt-O-Tronic
author_rank: Frequent Contributor
timestamp: January 24, 2017, 04:03:19 pm
content: Great thread idea,strangersound! There's a lot of win here! Looking forward to lots of continuing posts.

author: mrcrud5
author_rank: Contributor
timestamp: January 24, 2017, 04:38:49 pm
content: I made a tattoo machine power supply

author: joeqsmith
author_rank: Super Contributor
timestamp: January 25, 2017, 01:36:07 am
content: Some nice woodworking here! I've attempted some hand carving in the past.Seeing the tattoo power supply box, seemed like this would be a good follow on. This was joystick I made for the IBM AT. I had a friend who repaired large arcade games who gave me the digital stick. The small computer reads the digital signals and simulates the pots. It may have been one of the first auto fire joysticks for the PC for all know. You can also record your movements and play them back with it.

author: NiHaoMike
author_rank: Super Contributor
timestamp: January 25, 2017, 02:37:58 am
content: A 6 core workstation, built in 2012, still in use today. Initially planned on upgrading CPU/MB after 5 years but there turns out to be little reason to do so.A hybrid A/C and heat pump water heater.A gaming PC in a DVD player case. (Graduation present for my cousin, who enjoys gaming.)A HD audio DAC/headphone amplifier. (https://github.com/NiHaoMike/OpenDAC-HD)An external GPU adapter for a laptop, still need to find a good case to put it in.

author: Mr.B
author_rank: Unknown
timestamp: January 25, 2017, 02:59:45 am
content: This thread has some great inspiration.Thanks for starting it.

author: joeqsmith
author_rank: Super Contributor
timestamp: January 25, 2017, 03:05:31 am
content: Quote from: NiHaoMike on January 25, 2017, 02:37:58 amCan you give a little info about this project?This was a small model dyno I made some time back. I built this to get some idea how to put together a larger one and have never owned any RC toys. An earlier version is also shown. The absorber started out as a brush DC motor. It was bad in many ways. The final absorber is brushless and uses ceramic bearings. The ground shaft is used to align it. The electronics part is the first programmable load and voltage supply.

author: Bud
author_rank: Super Contributor
timestamp: January 25, 2017, 04:51:37 am
content: A weekend project before a HF contest - an antenna Pi-tuner in a computer power supply box.

author: NiHaoMike
author_rank: Super Contributor
timestamp: January 25, 2017, 04:59:25 am
content: The external GPU adapter started out as a 1x to 16x extender kit. I made an Expresscard adapter for it and also added a little circuit to control the power supply. The power supply itself is a 1U server PSU. What's difficult is the case since I'm trying to find something just big enough to contain everything and be well vented for the GPU. The two fan ("Hooters style") GPUs especially need a lot of ventilation for cooling.What gets more interesting is the software side. For now, I just have a shell script to start a second X server and relay input events to it.

author: Bud
author_rank: Super Contributor
timestamp: January 25, 2017, 05:01:04 am
content: A Morse keyer and PIC-based GPIB controller

author: Vgkid
author_rank: Super Contributor
timestamp: January 25, 2017, 06:28:16 am
content: Quote from: NANDBlog on January 24, 2017, 03:46:56 pmCan you go into details on this?

author: vk3yedotcom
author_rank: Frequent Contributor
timestamp: January 25, 2017, 10:23:01 am
content: A drone machine

author: krivx
author_rank: Frequent Contributor
timestamp: January 25, 2017, 11:36:45 am
content: Quote from: capt bullshot on January 24, 2017, 06:31:48 amWhat are you using to score the copper? I tried this recently and had problems, are you using an abrasive grinding tool?

author: capt bullshot
author_rank: Super Contributor
timestamp: January 25, 2017, 11:47:08 am
content: Quote from: krivx on January 25, 2017, 11:36:45 amIn this particular case I've used a Dremel with a thin grinding wheel (these small discs, about 1mm thick and 25mm diameter), working free hand. Some kind of mechanical guidance would be useful, but I've neither an idea where to get a suitable one nor how it would look like. Holding the dremel in your hand, the results are usable for rather coarse work.I've also tried a stanley knife, useful only for long straight cuts in the copper.

author: krivx
author_rank: Frequent Contributor
timestamp: January 25, 2017, 11:57:55 am
content: I've found that Stanley knives don't work well, the blade tends to wander once it starts cutting into copper (even when using a straight edge) and it gets dull after a few cuts.

author: Spuddevans
author_rank: Unknown
timestamp: January 25, 2017, 01:29:43 pm
content: Here's a HiFi amp I made a few years ago.It has a valve pre-amp stage and then 2 LM4880 "gainclone" amp modules (for bi-amping)It was only after assembling the amp I discovered that the heaters in these valves are shielded, so no lovely valve glow (future mod to add a couple of LED's to illuminate the valve's for a fake glow)I made some custom knobs out of solid brass, and also did a custom drill pattern on the lid for ventilation. The case is a 2U 19" rack case.Front viewLidInsideAnd for the woodworker's among us here's a old pic of the 5-string Bass I made (including custom turned Ebony knobs)Tim

author: xrunner
author_rank: Super Contributor
timestamp: January 25, 2017, 01:46:48 pm
content: Quote from: Spuddevans on January 25, 2017, 01:29:43 pmWow that's really cool. I've got something to post but it's not anywhere near that extravagant. I need to solder on one more wire but I'll try to post it today.

author: Spuddevans
author_rank: Unknown
timestamp: January 25, 2017, 04:07:22 pm
content: Quote from: xrunner on January 25, 2017, 01:46:48 pmDon't be deceived, that is all a collection of other people's work, I just bought and assembled the kits and adapted a case for it.I need to re-work the amp, when moving house I neglected to remove the valves from poking out the front and broke one(they were a matched pair), and when trying to trace/cure a very faint hum I accidentally introduced a much louder hum(I re-wired the power rails, or more correctly, the earth's, incorrectly and introduced a ground loop. I only found out when I completely re-assembled the amp. serves me right for not testing it before re-assembly)I haven't built anything for a few years, but I'm getting the building bug again (and I have a part built HF transceiver calling out to be finished)Tim

author: Gyro
author_rank: Super Contributor
timestamp: January 25, 2017, 04:37:38 pm
content: Mercury Barometer (Built about 25 years ago and well sealed!). Valve Amplifier, and X-Ray tube electric 'candles' (to stop the wife leaving soot marks on the wall).

author: tkuhmone
author_rank: Regular Contributor
timestamp: January 25, 2017, 05:09:02 pm
content: Lathe work... I had some old wood material for the project - could be 150...200 years old. Still some material left, for future projectshttps://timokuhmonen.smugmug.com/Other-2/Lathe-work/i-mkpKt9W

author: george graves
author_rank: Super Contributor
timestamp: January 25, 2017, 05:38:30 pm
content: Resistance Decade Box - Resistor Substitution Boxhttps://www.tindie.com/products/redrocketlabs/rbox-mini-resistance-decade-substitution-box/

author: xrunner
author_rank: Super Contributor
timestamp: January 25, 2017, 05:41:31 pm
content: Working on this, it's a special load for a transmitter that you can use to calibrate the SWR metering. You can find this type of test called out in many service manuals for ham radio servicing.It consists of three 100W 50 ohm RF loads attached to a good heat sink. The first two are always in parallel so as to present a 25 ohm load, which creates an SWR of 2.0. You can also switch in a third load to make 16.6 ohms, which creates an SWR of 3.0. All I have left to do now is attach a small coaxial cable to the left side.

author: RoGeorge
author_rank: Super Contributor
timestamp: January 25, 2017, 06:51:40 pm
content: Years ago I was somehow ashamed that I could't afford a decent PC rig, but now I find it pretty cool!

author: xrunner
author_rank: Super Contributor
timestamp: January 25, 2017, 06:57:55 pm
content: Quote from: RoGeorge on January 25, 2017, 06:51:40 pm...

author: Melt-O-Tronic
author_rank: Frequent Contributor
timestamp: January 25, 2017, 07:30:29 pm
content: I looked at the resistor substitution box and thought "that's beautiful!", then the PC and thought "that's beautiful in atotallydifferent way!"This thread is pure gold.

author: vk3yedotcom
author_rank: Frequent Contributor
timestamp: January 25, 2017, 08:03:49 pm
content: This 100 milliwatt transceiver fits in a small food container and can contact people hundreds of kilometres away.

author: joeqsmith
author_rank: Super Contributor
timestamp: January 26, 2017, 12:55:51 am
content: Quote from: NiHaoMike on January 25, 2017, 04:59:25 amThanks. Do you have a blog or something with more details?I am curious if your plan was to use the GPU for a coprocessor and if so, how bad is it moving data to/from the card? Are you planning to write your own library then to support CUDA?Seem like an interesting project.

author: strangersound
author_rank: Regular Contributor
timestamp: January 26, 2017, 02:00:46 am
content: Quote from: Melt-O-Tronic on January 25, 2017, 07:30:29 pmYeah it is. I knew the folks here would come through with some good stuff. Mad science!

author: NiHaoMike
author_rank: Super Contributor
timestamp: January 26, 2017, 02:13:16 am
content: Quote from: joeqsmith on January 26, 2017, 12:55:51 amIt's really so I could have a portable gaming setup. I already had the 560ti lying around so it ended up around $20 in parts to connect it to a T420 that has a very usable CPU but a way outdated GPU. The 1x doesn't really affect things much given it's a 2GB card. (Games generally don't use a lot of bandwidth provided there's enough VRAM.) Some compute apps will slow down considerably (if they use a lot of bandwidth), while others are virtually unaffected.

author: Ampera
author_rank: Super Contributor
timestamp: January 26, 2017, 02:29:34 am
content: Quote from: RoGeorge on January 25, 2017, 06:51:40 pmMy solution is to use a wood board or a cardboard box.I made a 486 Socket 3 machine from parts.While that may not seem special, and it may be something many of you have done before.I did it a couple months ago.I also have a Slot 1 machine I just finished, and a Socket A machine I have had for ages. My main machine is a very ghetto i7-4790k machine with a GTX 970.

author: joeqsmith
author_rank: Super Contributor
timestamp: January 26, 2017, 02:50:05 am
content: I did make some attempts at carving as I got older. This Jay was the last thing I ever carved.

author: alank2
author_rank: Super Contributor
timestamp: January 26, 2017, 03:50:49 am
content: My favorite thing I've made is a micro Enigma that I call the microEnigma:These two pictures are an earlier prototype, the one in the video has an oak tray I cut on the CNC.

author: QuantumLogic
author_rank: Contributor
timestamp: January 26, 2017, 04:04:12 am
content: Made this portable battery-powered DC CV/CC power supply between Feb-May 2016 from mostly Chinese-sourced components, modules and parts.Front and back panels were designed in Blender and 3D printed by Shapeways.It can be powered from AC mains via an external 12V 4A power brick w/2.5mm jack or from the internal 4x18650 2500MAh Samsung Li-Ion cells. Switch on back (not shown) selects between battery, batt charge, and external power mode.It can output 0-20V and 0-5A CV/CC but is limited to about 40W total output before things get a bit wonky and it cuts out. (The AC power brick drops voltage severely under load (cheap crap supply) and the Li-Ion protection board I picked is only rated for 4A continuous). I originally designed it to be used with the DP20V2A LCD Power Module (thus is the reason for the components chosen), not the DPS3005 that is now installed (they are both the same panel size so are easily swapped). I wanted the 5A at lower voltages (and didn't care about not having >20V or >40W.

author: Gary350z
author_rank: Regular Contributor
timestamp: January 26, 2017, 04:09:50 am
content: Quote from: joeqsmith on January 26, 2017, 02:50:05 amVery nice.

author: PointyOintment
author_rank: Frequent Contributor
timestamp: February 02, 2017, 03:42:17 am
content: Quote from: QuantumLogic on January 26, 2017, 04:04:12 amWhat's the reason for those two meters on the right? They seem redundant with the DPS3005's onscreen numbers.

author: basinstreetdesign
author_rank: Frequent Contributor
timestamp: February 02, 2017, 05:53:20 am
content: Nothing too exotic here. A stereo tube amp:http://imgur.com/a/YmdxYTube curve tracer:https://www.instructables.com/id/Tube-Curve-Tracer-Ver-11/L/C meter:https://www.instructables.com/id/InductanceCapacitance-Meter-Saga/

author: james_s
author_rank: Super Contributor
timestamp: February 02, 2017, 06:47:36 am
content: This is still a work in progress but I've been working on a miniature Asteroids arcade game based on a cheap Altera Cyclone II FPGA board and a daughterboard I designed myself, it uses a VGA DAC to generate the X, Y and Z signals and has an amplifier section with adjustable gain and offset for the deflection signals. The monitor is a real vector monitor made from a cheap 5" B&W CRT TV set with the deflection yoke rewound. The prototype deflection board was done by somebody else but an improved and more integrated board is in my queue or stuff to do. The VHDL originally came from fpgaarcade.com but I've done quite a few modifications to port it to my hardware and remove the rasterizer he used and allow it to run the original Asteroids ROMs in addition to Asteroids Deluxe which is what it was originally set up for.One of these days I'd like to make a miniature desktop replica of the upright cabinet for it.

author: Melt-O-Tronic
author_rank: Frequent Contributor
timestamp: February 03, 2017, 05:55:59 am
content: Quote from: james_s on February 02, 2017, 06:47:36 amImustknow more! I had no idea that vector monitors had a different style of deflection yoke and the idea of rewinding a yoke makes my jaw drop.

author: james_s
author_rank: Super Contributor
timestamp: February 03, 2017, 09:14:13 am
content: Quote from: Melt-O-Tronic on February 03, 2017, 05:55:59 amIn a raster scan monitor the horizontal deflection rate is many times faster than the vertical refresh rate so the vertical windings have a much higher inductance. Rewinding involves heating the adhesive to pop loose the ferrite core halves, then removing the several hundred turns of wire and winding back a smaller number, 80-100 turns per half. This greatly reduces the inductance down to a range that allows the defection amplifier running at reasonable rail voltages to push enough current through the coils to move the beam rapidly. Beam position is proportional to current through the deflection coils.I'm not the first to do this, I got the idea from a fellow tinkerer named Fred Kono.http://www.thedefenderproject.com/other-arcade-games/building-a-vector-monitor-from-a-raster-tv/I'm not even the first to build a genuine vector game using an FPGA, I got that idea from here:https://spritesmods.com/?art=bwidow_fpgaI am however the first I'm aware of to build a vector game out of such a cheap FPGA board, and using a quality 10 bit DAC results in nice quality vectors.

author: george graves
author_rank: Super Contributor
timestamp: February 03, 2017, 12:11:30 pm
content: Quote from: Melt-O-Tronic on January 25, 2017, 07:30:29 pmThanks!

author: GK
author_rank: Super Contributor
timestamp: February 03, 2017, 01:55:12 pm
content: I designed discrete deflection coil driver amplifiers for my monitor which current limit at +/-2A and run on unregulated rails (nominally) of +/-42V. The beams are individually activated by logic signals applied to the banana jacks on the front panel. Funny, I rewound my vertical ferrite halves with the same number of turns and also used a 555 astable in my HV circuit, but switching the LOPT primary current via a MOSFET rather than a BU108. I hadn't seen the Asteroids games before and I hadn't contemplated making a vector-based video generator. Hmmmm......

author: james_s
author_rank: Super Contributor
timestamp: February 03, 2017, 05:04:39 pm
content: That's a beautifully made monitor, what is it intended to be used for?I didn't know there was anyone who hadn't seen Asteroids before, it was a smash hit and was nearly as ubiquitous as PacMan during the golden age of arcade games. I actually like the original Asteroids better than the Deluxe version, it's absolutely perfect, simple to play, difficult to master, fantastic physics and sound effects, and it makes use of the unique capabilities of a CRT vector monitor better than any game ever made. The eye-searing photon bullets cannot be emulated by any other display technology, nothing else has anywhere near enough dynamic range.

author: mtdoc
author_rank: Super Contributor
timestamp: February 03, 2017, 05:32:13 pm
content: Keeping in the spirit of the OP to include some non-electronics creations, here's the chicken coop I built this year. It will soon turn into an electronics project though since the next stage is the automatic dusk/dawn chicken door opener, a temperature monitor, and water de-icer.

author: RoGeorge
author_rank: Super Contributor
timestamp: February 03, 2017, 09:05:38 pm
content: Quote from: mtdoc onTodayat 04:32:13

author: mtdoc
author_rank: Super Contributor
timestamp: February 03, 2017, 09:49:59 pm
content: Quote from: RoGeorge on February 03, 2017, 09:05:38 pmHa! Don't I wish. The picture is deceiving. The solar panels are on a shed in the background. Here's a picture from a few years ago after I'd finished building that shed. The large PV array feeds in to my home back up power system. The small panel on the side is a 140 watt 12 volt panel that feeds a small 12 volt system for lights in the shed. I'm going to tap into that 12V system for power to the chicken coop.

author: Seekonk
author_rank: Super Contributor
timestamp: February 03, 2017, 10:47:26 pm
content: A little animation with a 328. Most of the plane parts are from a DC-8. Radar moves, lights flash randomly like a haunted ship. Even makes engine sounds. The garage a couple years ago. The concrete trucks came with 14 yards and one just looked at me and my wife. He said, "Do you know what you are doing or did you just watch a program on TV."

author: milamber
author_rank: Contributor
timestamp: February 05, 2017, 02:23:00 pm
content: IplGesendet von meinem Nexus 5X mit Tapatalk

author: anishkgt
author_rank: Frequent Contributor
timestamp: February 05, 2017, 03:06:16 pm
content: May be not Cool but my forst project with an Arduino. Arduino SpotWelder for 18650 cells.http://www.ebay.com/sch/josh.cisco/m.html?_nkw=&_armrs=1&_ipg=&_from=

author: razberik
author_rank: Frequent Contributor
timestamp: February 05, 2017, 11:14:27 pm
content: My little project from summer.Air conditioning is not very common in flats or houses here. Despite the fact that AC units are quite available and not very costly anymore.However it is not very feasible to do installation in rental flat. There is a lot of mobile units available, but not many people use it properly. Usually they dont seal the exhaust properly, so the unit is practically useless.Here is my solution. Coolexpert unit from distributor whose HQ and warehouse is here, so no problem with warranty.Exhaust is through DTD plank which is inserted in the window frame against its rubber sealing. I couldnt believe it, but it seals pretty reasonable. What is more, that plank reduces that annoying sun rays.Anyway, this air conditioning works very well in hot summer days.

author: Yansi
author_rank: Super Contributor
timestamp: February 06, 2017, 12:18:12 am
content: Made this board last week. A traction accumulator pack control board (Currently used with a 2kWh 300V one). Has two separate CAN interfaces. Only two layers.

author: mtdoc
author_rank: Super Contributor
timestamp: February 06, 2017, 12:48:12 am
content: Quote from: anishkgt on February 05, 2017, 03:06:16 pmIs there more information on this somewhere.?Also FWIW, I don't think you're going to sell many of those pcb's for $33 + $35 shipping. Not when you can buy a spot welder for a bit over $100 or build one with an inexpensive pcb for a different DIY version that is open source.

author: anishkgt
author_rank: Frequent Contributor
timestamp: February 06, 2017, 05:17:22 am
content: Quote from: mtdoc on February 06, 2017, 12:48:12 amThe details of the project are in the description of the listing. Sold 6 just a few more left.Sent from my iPhone using Tapatalk

author: mtdoc
author_rank: Super Contributor
timestamp: February 06, 2017, 05:42:06 am
content: Quote from: anishkgt on February 06, 2017, 05:17:22 amThanks, but I was thinking more along the lines of a schematic, the Arduino code, gerbers perhaps. Such as is available for Albert van Dalen's DIY spot welderhere,hereandhere.I'm thinking of building one of these as I need to spot weld some 18650s for an eBike battery pack. Good on you for selling your PCB's but I'm not seeing why I would buy one of your PCBs for $68 when I can get one of Albert's for about $20 with full documentation, code, etc available.BTW, I'm not trying to give you a hard time - just trying to understand more about your project. Regardless, congrats and good luck.

author: anishkgt
author_rank: Frequent Contributor
timestamp: February 06, 2017, 06:11:39 am
content: Albert's design is a basic design with the least components which is a good one. Mine was designed with safety of the circuit and end user in mind .The circuit incorporates a TVS diode at the AC side and two others in the DC side of the circuit as well.When building packs there is always a need to do multiple welds for a pack. My design incorporates that too, holding down the weld button for more than 2 seconds starts this sequence of 6 welds. With an audible alert after each weld and a 1.5 second delay between each.Yes the PCB, transformer and the IC that is sell is costly. Earlier i sold fully assembled at 54$(including shipping), latter realized that the transformer was hard to get and a bit costly too to buy as a bulk. With some time with the sales rep I've managed to get only the transformers for a cheaper price so that the end user could buy the other components.Those are just a few to compare the two PCB's. I have 120v/220v version in design and another with an automation to lower and raise the weld arm.

author: james_s
author_rank: Super Contributor
timestamp: February 06, 2017, 06:50:33 am
content: Quote from: mtdoc on February 06, 2017, 05:42:06 amYou don't need an Arduino to weld battery tabs. I built a capacitive discharge spot welder a few years ago specifically for that purpose, the electronics are very simple. It's just a bank of 22,000uF capacitors adding up to just over 1F. Then there's a variable 20V power supply based on a LM317, I'm using the built in current limiting of the regulator to limit charging current and it works fine although I'm sure something more elegant could be done. For the trigger I used a big stud mount SCR I found on ebay, and there's a relay to trigger it from a foot pedal, the relay disconnects the power supply and connects the SCR gate which triggers it into the probes. There's a Fault indication LED across the output that will light if for any reason the SCR is triggered with the probes open circuit. The capacitors are wired in banks soldered to #10 copper wires and those all feed into a couple of heavy bus bars made of flattened copper pipe. I've made dozens of battery packs with this thing, never had any trouble with it. The hardest part is finding an affordable source of suitable capacitors. I first tried one of those big car stereo 1F capacitors and it worked for about 10 welds then failed.

author: NiHaoMike
author_rank: Super Contributor
timestamp: February 06, 2017, 07:00:01 am
content: What about use a transformer (and driving circuit) so you can use a higher voltage but lower current capacitor bank?

author: anishkgt
author_rank: Frequent Contributor
timestamp: February 06, 2017, 07:04:13 am
content: The CD type spot welders are easier to design but the transformer has the advantage of running them from the mains and the current is more compared to the CD. There is design by ZEVAhttp://zeva.com.au/Projects/SpotWelder/

author: james_s
author_rank: Super Contributor
timestamp: February 06, 2017, 05:31:12 pm
content: All of the battery tab welders I've seen are the CD type, they're used because the very short pulse duration minimizes heating of the battery being welded. I've measured the current on mine at just a hair under 10kA, I don't recall the pulse width but it was in the nanoseconds.

author: mtdoc
author_rank: Super Contributor
timestamp: February 06, 2017, 06:47:48 pm
content: Quote from: anishkgt on February 06, 2017, 06:11:39 amWell, looking at your eBay listing again I see that I missed that in addition to the PCB you are including the transformer and programmed Atmel IC for the $33 +$35. That is much more reasonable and explains the high shipping cost! Based on the title of the listing and the picture it appeared to me that you were asking that much for the PCB alone.You really should change the title and have the main photo show what is included (PCB, transformer, and IC). I'm sure I'm not the only one who has missed the details of what's included that are only found in the text of the item description.

author: mtdoc
author_rank: Super Contributor
timestamp: February 06, 2017, 07:12:55 pm
content: Quote from: james_s on February 06, 2017, 05:31:12 pmOne problem I see with building a CD type is the cost of the ultracapacitors. Microwave transformers on the other hand are easy (and free) to come by.

author: james_s
author_rank: Super Contributor
timestamp: February 06, 2017, 08:23:27 pm
content: I used ordinary high quality electrolytic capacitors, but lots of them. I think mine has a bank of 50 22,000uF 25V capacitors in parallel, the cost is an issue but I was able to find them from a surplus dealer so the total cost of the unit was under $100. Most of the small parts I had in my junkbox though and the case came from a piece of old equipment I found in the e-waste bin at work.

author: anishkgt
author_rank: Frequent Contributor
timestamp: February 06, 2017, 10:50:20 pm
content: Another reason why I would stick to MOT. not every would have easy access to those caps.Sent from my iPhone using Tapatalk

author: rstofer
author_rank: Super Contributor
timestamp: February 06, 2017, 11:26:45 pm
content: I had problems 'getting' differential equations in college and grad school. I could never 'see' how the equations worked. So, in my old age, I decided to revisit the topic by building a small analog computer.Electronically, this project is built on a 2.5"x3.8" PCB that is packed pretty tight but the real issue was building the panel. For this, I converted a Grizzly G0704 Mill to CNC just to drill the holes. It is important that the spacing be perfect if dual plugs are to be used. Besides, warped lines of jacks just doesn't look good.The front panel is made from two layers of acrylic with the legends being printed on a piece of paper sandwiched between the acrylic sheets.My longer term goal is to build a much larger unit but with just two integrators, I can solve most equations of motion since I can integrate acceleration to get velocity and then integrate velocity to get displacement. It's really quite a capable little machine.http://www.grizzly.com/products/Drill-Mill-with-Stand/G0704

author: james_s
author_rank: Super Contributor
timestamp: February 07, 2017, 08:11:15 pm
content: Quote from: rstofer on February 06, 2017, 11:26:45 pmThat's totally cool, beautifully done. Love the big analog Simpson panel meter.

author: james_s
author_rank: Super Contributor
timestamp: February 07, 2017, 08:14:06 pm
content: Quote from: anishkgt on February 06, 2017, 10:50:20 pmSure they do, the caps are readily available, the trick is finding them cheaply but with patience it can be done.CD welders have advantages, there are things they can do that a transformer welder can't. Transformer welders have other advantages, they both have their place. It's a bit like comparing a DSO to an analog scope, sometimes the more specialized gear really is much better for a particular task, even if it costs more.

author: alank2
author_rank: Super Contributor
timestamp: June 03, 2017, 07:38:04 pm
content: Somewhat a repeat of my earlier post, but when Elecrow offers 5pcs of 10x10cm for $4.90 in practically any color, I couldn't help myself but to try it.Besides, this is too good a thread to see it go by the wayside, let's see some cool stuff YOU made!

author: james_s
author_rank: Super Contributor
timestamp: June 03, 2017, 09:15:47 pm
content: Quote from: alank2 on June 03, 2017, 07:38:04 pmIs that your design? Is the source available? My little brother is fascinated with the German Enigma machine and various other WWII history, I could build one of those to give him for his birthday next time.

author: daveyk
author_rank: Frequent Contributor
timestamp: June 03, 2017, 09:56:06 pm
content: Quote from: mrcrud5 on January 24, 2017, 04:38:49 pmAre you marketing this tattoo power supply yet? My wife does tattooing. Consistency with the machines and power supplies are a problem that the artist just has to get a feel for it. I thought they were just simple power supplies. I like that yours can show the speed and cycle on time of the coils. That could be a great tool.DaveSent from my iPhone using Tapatalk

author: basinstreetdesign
author_rank: Frequent Contributor
timestamp: June 04, 2017, 05:24:39 am
content: I have an account on Instructables and sometimes there are some good stuff there but I got tired of reading about projects that just seemed too easily done. Things seldom went wrong. So I decided to post a diatribe about one of mine in which almost everything went wrong that could.It was a C and L meter I built into a small candy tin. Here is the link:https://www.instructables.com/id/InductanceCapacitance-Meter-Saga/It is a fairly long read but it does detail how I had to do the hardware design three times, building each one up just to discover some death-dealing failing that would render it useless and force me to redo it all over again with a different philosophy. All that and my laptop completely died half way through as well, so I had to go buy a "new" one of those, too and re-install everything from scratch. In the end, after about 4 mo. I did finish it after all that effort but didn't have a really good way to calibrate it. Its only good within about 10%.Even so, it serves its purpose well enough.

author: vk3yedotcom
author_rank: Frequent Contributor
timestamp: June 05, 2017, 11:09:13 am
content: Some radio projects* Thousand hour radio (draws only 2.5mA)* FM superregenerative receiver* A valve (tube) regenerative radio that requires only 12 volts high tension