Electrical Engineering V3 - Developers

I could never really see a universal flash/EEPROM programmer being all that useful considering how often manufactures like to change up the opcodes to interface the bloody things. Then again, I suppose more respectable programmers have different profiles that you can setup.

[QUOTE=false prophet;50440665]Figured I would ask here. Have any of you built something and thought it was nice enough to revision so you don't electrocute yourself anymore? I want to cover my lighting project with a plastic mold but I don't know where or how to do that. A friend noticed it and asked if my time machine exploded...[/QUOTE] When in doubt hot glue???? No but really, you can look at different thermoplatics. If you thing does not give off a huge amount of heat you can look at something like [url]https://www.adafruit.com/products/2504[/url] , if not you can look at maybe getting some of those plastic sheets, and heat them with a hot air gun and use wood as a template. Just make sure to wear gloves and remember that it is hot plastic.

[QUOTE=andreblue;50441483]When in doubt hot glue???? No but really, you can look at different thermoplatics. If you thing does not give off a huge amount of heat you can look at something like [url]https://www.adafruit.com/products/2504[/url] , if not you can look at maybe getting some of those plastic sheets, and heat them with a hot air gun and use wood as a template. Just make sure to wear gloves and remember that it is hot plastic.[/QUOTE] Polycaprolactone is actually really easy to handle, it has a low thermal conductivity so you can't really burn yourself on it.

[QUOTE=false prophet;50440665]Figured I would ask here. Have any of you built something and thought it was nice enough to revision so you don't electrocute yourself anymore? I want to cover my lighting project with a plastic mold but I don't know where or how to do that. A friend noticed it and asked if my time machine exploded...[/QUOTE] Sometimes the answer is as easy as an old piece of tupperware. :v:

I like the way you think, friend!

Who here's got the up and up on frequency multipliers? I've got a vfo that goes from ~1MHz to 200Mhz and I'd like to up the range by switching in and out a 3x multiplier, and maybe even a 4x multiplier to get 1MHz to 800MHz potentially. Maybe even more. This is for a wideband antenna analyzer I'm working on.

First* test drive, just to test the driver and motors. [vid]https://dl.dropboxusercontent.com/u/43645231/photos/electro/rover1.webm[/vid] It drives pretty straight :dance:, the [URL="http://grobotronics.com/images/detailed/4/metal_ball_casters.jpg"]ball caster[/URL] I use seems pretty garbage and probably causes most of the offset, as I can even hear it rattling when reversing direction. I do have encoders on both wheels tho (not in use atm), which can help to compensate it a bit. The arduino dangling around is temporary, I'm lacking female headers to finish my board. * I tested it a bit before and sprayed some lubricant in the ball caster which helped.

I just saw this [url]http://www.bigmessowires.com/2016/06/04/db-19-resurrecting-an-obsolete-connector/[/url] I think it's pretty amazing that demand from hobbyists was enough to get a production run of a connector.

Time for some gory near-death horror story: Last weekend I was at the Gulaschprogrammiernacht (goulasch programming night), a kind of hacker meetup. I was responsible for setting up the lounge. Traditionally, we have a 10x10x10 LED-cube that we fly in a gigantic rig above the lounge. The cube is a very popular eye-catcher usually resulting in people laying down below it and staring into the cube while they're high. [t]https://entropia.de/images/7/70/DSC02526.JPG[/t] [i]Lounge, with the cube flying in the rig[/i] We had one team assigned to constructing the cube. That involves screwing together the frame and pre-tensioning the wires for the balls, aswell as hooking up the electronics. Once that was done, we did a quick power-on test to confirm the cube is in working order. It displayed the test-pattern correctly, and handed the cube over to the rigging team. The cube was flown using a small 3x3m rectangle frame, which was attached to the main rig. The cube was to be attached to the frame with a rigging sling (basically a metal chain in a sturdy sheath) in each corner. And this is where the horror started... [t]https://entropia.de/images/c/c5/DSC02512.JPG[/t] [i]Cube and 3x3m frame[/i] By the time we attached the cube to the frame we were all quite tired. Thus we just wanted to get shit done, especially as we still had a lot of setting up ahead of us. We hoisted the rig up and placed the cube under the frame. We had to lift it slightly off the ground to get the sling around the corner of the frames. The cube isn't really heavy (~40kg), but the frame of the cube consists out of L-shaped metal profiles, so it was extremely uncomfortable to hold it. Once we were done hoisting and safeing the cube we were quite happy. We routed the power and ethernet cables up to the control center. We coiled up the ethernet cable and laid it down in a corner. We then powered on the cube to check if it's still working, and we once again saw the test pattern. After that we called it a day and got some dire needed sleep. The next day we set up a shitload of thing, with the cube being extremely low priority. We spent the entire day setting up the projectors and their computers, creating programs for the lights in the rig and debugging our control softwares (We ran the entire light and visuals on custom software). The event had already started when we finally decided to hook up the cube to our network. My colleague, let's call him Joe, started unrolling the ethernet cable towards the switch, and plugged it in... Crap. The entire thing went dark, the fault interrupt triggered. We went into full panic mode and unplugged everything. We turned power back on and started plugging in everything one by one to isolate the cause, but nothing triggered the fault interrupt. Then it dawned on us that the ethernet cable could be the culprit. To confirm this, we plugged it into the switch again... BANG! And enormous spark formed between the ethernet cable and the switch, and the rig was dark again. [t]https://my.mixtape.moe/hgfesu.jpg[/t] [i]Check out the left shield tab on port 15[/i] Something was terribly wrong, and we whipped out our measurement equipment. We measured a dead short between the ethernet's shield and one of the power cable's prongs. [B]Fuck.[/B] We immediately taped off the plug with a plastic bag and decommissioned the cube for the event. We kinda salvaged the cube by using 2 of our movingheads to illuminate the balls externally, which also looked pretty cool. [t]https://entropia.de/images/0/00/DSC02530.JPG[/t] [i]Externally lit cube[/i] The days went by, the event was over, and we deconstructed the cube. We were eager to find the cause, and it quickly jumped into our eyes: A mains-carrying cable was pinched by the sling and had it's insulation sheared off. [t]https://my.mixtape.moe/ndvgbj.jpg[/t] [i]PoE-Adapter[/i] It's a bloody wonder nobody got seriously hurt. The cable was lying around publicly accessible all day long and Joe could've touched the connector multiple times while unrolling the coil. Lessons learned: Never trust shady constructions to be safe. The cube was constructed by an artist who has no EE-background. The wires are all flapping in the breeze, and this whole thing was just a disaster waiting to happen.

[QUOTE=DrDevil;50459101]The cube is a very popular eye-catcher usually resulting in people laying down below it and staring into the cube while they're [b]high[/b]. [/QUOTE] Heh :v:.

[QUOTE=Fourier;50459505]Heh :v:.[/QUOTE] You wouldn't believe how many puffs of weed flew by while we set up everything...

[QUOTE=DrDevil;50459549]You wouldn't believe how many puffs of weed flew by while we set up everything...[/QUOTE] Well here where I live lots of techies/IT/EE/Math guys/girls smoke too.

I had to install a new ground strap for my antenna. [IMG]http://i11.photobucket.com/albums/a166/ballsandy/around%20the%20house/IMG_4193.jpg[/IMG] Jesus fucking christ copper wire is expensive.

Now try doing that from a third story roof :)

I still gotta mount the counterweight for the shortwave antenna on the other side of the house. It's just a metal L-shaped bracket with a pulley but fuck me, it has to be mounted to the soffit and that's 30' up.

No more light bulb dummy loads for me. :dance: [IMG]http://i11.photobucket.com/albums/a166/ballsandy/IMG_4204.jpg[/IMG] Resistors on the left give a 2A load at 5v and the two on the right do a 2.5A load at 12v. The LED's just indicate that a load is active. I have to verify the current draw on Wednesday as my bench supply dips when loaded down heavily.

Found out recently that chinese domestic actual Fluke meters are a hell of alot cheaper than US/NA ones. And then AvE discovered this shit about them: [video=youtube;FUmbsBYVTQ0]http://www.youtube.com/watch?v=FUmbsBYVTQ0[/video]

[QUOTE=pentium;50468884]Resistors on the left give a 2A load at 5v and the two on the right do a 2.5A load at 12v. .[/QUOTE] Also known as 2.5 ohms and 4.8 ohms?

More or less. I saw the resistors for free in a box and knew what I had to make. I also got three or four 100W 50K power resistors. I got no idea what the fuck to use those for.

Could anyone from the US let me know of some reliable places to get electrical parts from? I've never had to buy parts and I'd like to start putting a project together physically

[QUOTE=solid_jake;50473503]Could anyone from the US let me know of some reliable places to get electrical parts from? I've never had to buy parts and I'd like to start putting a project together physically[/QUOTE] ebay Digikey Mouser Amazon Allied Electronics Sparkfun Element14 For things like resistors, capacitors and LEDs it's usually cheapest to get a set off ebay, even more so if you're willing to wait for delivery from China.

[MEDIA]http://www.youtube.com/watch?v=yyi9QQjCltw[/MEDIA] Not much yet, just a microcontroller to configure the display mode and such. Only 6 colours hooked up as I've lost most of my female-female dupont cables, and they struggle at high speed of a 60Hz display anyway. The video is at 1/4 speed (240FPS mode on my 6P), hence it looks slow but that's more to show that it's actually running pretty fast.

To add to my previous post, I love it when datasheets have errors that make me very confused. Was wondering why the 16-bit RGB mode was 574 not 565... as it turns out, there is something a bit off. [img_thumb]http://i.imgur.com/vHKhmB8.png[/img_thumb] See the mistake?

Lets take a moment to respect the individuals who are not electrical engineers. [quote]Seller was asking $89 for it but I checked the CRT and it's really really bad. Bumping the heater didn't budge the needle at all, also he had plugged it in, before I got there and something smoked, I could smell it in the house as soon as I walked in (and also in the Van all the way home, p.u.) hopefully a resistor and not the transformer, which was still warm when I arrived. - I also found out the 5U4 was cracked from the heat and the heater arced to the plate, it still stinks too, I really hope the transformer isn't damaged. What's really frustrating is the seller caused this damage by plugging it in after I was on my way to pick it up, guess he thought it would sell better if it was working.[/quote] [quote]There was an online auction recently where the seller plugged in a twin rectifier tube set, and wrote something like "I watched the first tube glow purple and then sparkle, and then it stopped. Then the second tube did the same thing. Now nothing happens when I plug it in."[/quote] [quote]I had the same problem with my 54 RCA. They had plugged it in prior to me arriving. "It had sound but no picture. It was only on for 10 minutes". One rectifier tube was blown to bits inside! I'm 90% sure the transformer is shot. B+ way too high and I can feel a shock if I touch the transformer's case. Not a good sign. [/quote]

My parents iPad 4th gen suddenly stopped being able to charge, and when the battery went empty it became a paperweight. They didn't think/have time to save the photos on it, so I am currently charging the battery to hopefully save them :-) Damn that digitizer/glass is annoying to peel off, splinters everywhere... Luckily the LCD is not attached to the glass. [IMG]https://dl.dropboxusercontent.com/u/100328/Facepunch/Billede 10-06-2016 21.00.44 resized.jpg[/IMG]

[QUOTE=solid_jake;50473503]Could anyone from the US let me know of some reliable places to get electrical parts from? I've never had to buy parts and I'd like to start putting a project together physically[/QUOTE] I'm in the UK but I've had good experiences with Farnell (element14 over there) and Mouser, eBay is good for odd bits if you need something strange or specialist in low quantity like LCDs, or if you want an assortment of jellybean parts, but I generally opt for Farnell as they have free next day shipping here. Mouser seem to have a better range for some vendors, noticed especially that they carry more of the Lattice development boards, but also a wider range of ICs too. Digikey looks good but I've never ordered as I will get charged VAT+surplus when it arrives whilst Mouser will pay the VAT ahead of time which is fantastic.

Got a little something to play with [t]https://my.mixtape.moe/qqunyb.jpg[/t]

[QUOTE=DrDevil;50504152]Got a little something to play with [t]https://my.mixtape.moe/qqunyb.jpg[/t][/QUOTE] Oh yes, I've got one of those laying about somewhere too, I can't remember which pins enable the power supply, there should be a diagram somewhere online. I never did anything with it in the end XD

[QUOTE=nuttyboffin;50504544]Oh yes, I've got one of those laying about somewhere too, I can't remember which pins enable the power supply, there should be a diagram somewhere online. I never did anything with it in the end XD[/QUOTE] I found this online: [url]https://my.mixtape.moe/woervt.jpg[/url] (Connecting the 12V feedback makes it turn off though, I only have A6 to C2 connected)

those things are great for powering radios. My big guy eats up 40A on transmit.