Electrical Engineering V3 - Developers

[QUOTE=ben1066;50226752]Have you guys seen this [url]http://limesdr.org/[/url] ? A 300$ (though 200$ early bird) USB 3.0 SDR with transmit and receive capability. Anything I'm missing or is this actually as great as it sounds?[/QUOTE] What is it with people and naming projects after fruit? First the raspberry pi, then the banana pi, then the orange pi, then kiwisdr (admittedly that's from New Zealand) and now we have limesdr. Somebody call me when we get to Mocha Chai Soy Vente Oscilloscope. [editline]29th April 2016[/editline] The LMS7002M chip in the LimeSDR is a 12bit ADC/DAC, which makes this a better value proposition than a HackRF but if you want an HF SDR you're better off with a KiwiSDR.

Workbench? I only have a work- and party-bench! [t]https://my.mixtape.moe/krcgww.jpg[/t] [t]https://my.mixtape.moe/ifhxgk.jpg[/t]

Awww yeahhh getting that electronic high off the magic smoke.

[QUOTE=LoneWolf_Recon;50231324]Awww yeahhh getting that electronic high off the magic smoke.[/QUOTE] I can [I]feel[/I] the electrons duuude

Holy fuck fiberglass dust gets [b]everywhere[/b] [editline]1st May 2016[/editline] ITS IN MY EYES

[QUOTE=Tobba;50234486]Holy fuck fiberglass dust gets [b]everywhere[/b] [editline]1st May 2016[/editline] ITS IN MY EYES[/QUOTE] Always. Always have a fan/vacuum on when cutting FR-4. And I guess a dust mask or safety glasses.

I'm going to be making a motor driver with 3-4 MOSFETs, a few caps, resistors, and a gate driver. Do you guys know of a good place to get a decent amount of strip board? And would you all recommend strip boards with a pattern or all independent pins? I tend to get stuff I don't need quickly from China, just cause it's dirt cheap. But I would like some of this a little sooner than a month. Oh and here is a shitty drawing ( and it's not complete as it doesn't include gate driver components ): [t]http://i.imgur.com/GBsfqYT.png[/t]

[QUOTE=gjsdeath;50240700]I'm going to be making a motor driver with 3-4 MOSFETs, a few caps, resistors, and a gate driver. Do you guys know of a good place to get a decent amount of strip board? And would you all recommend strip boards with a pattern or all independent pins? I tend to get stuff I don't need quickly from China, just cause it's dirt cheap. But I would like some of this a little sooner than a month. Oh and here is a shitty drawing ( and it's not complete as it doesn't include gate driver components ): [t]http://i.imgur.com/GBsfqYT.png[/t][/QUOTE] if you have some sort of electronic parts store nearby, that is where i get mine at a decent price when i need some.

What are those resistors doing across the drain-source of each MOSFET? If you're planning on using a high power motor (which from those MOSFETs it seems you are) you don't want to use stripboard, get a cheap PCB made instead with some nice fat traces, I'd also suggest putting the gate driver somewhere else if you haven't prototyped it yet (just in case you screw it up).

If you use more then one row, thick with solder, he would be able to get by decently.

[QUOTE=Chryseus;50242836]What are those resistors doing across the drain-source of each MOSFET? If you're planning on using a high power motor (which from those MOSFETs it seems you are) you don't want to use stripboard, get a cheap PCB made instead with some nice fat traces, I'd also suggest putting the gate driver somewhere else if you haven't prototyped it yet (just in case you screw it up).[/QUOTE] Those resistors are in this other control board I was looking at. I thought they had something to do with ringing prevention. And I might make the gate driver a second board, I'm also debating on whether to use one gate driver for all the MOSFETs or one per each MOSFET. One should be plenty powerful enough. Theyre MAX4420CPA drivers. [QUOTE=andreblue;50242875]If you use more then one row, thick with solder, he would be able to get by decently.[/QUOTE] I was also thinking about running a decent gauge wire along it too. I considered making/etching my own PCB, but for this iteration I think I'm gonna go with strip board and just reinforce. Next revision will probably use a custom PCB. I wanted to find out how well the circuit works before going through all the trouble of a custom PCB.

[t]http://i.imgur.com/9MK5epz.jpg[/t] Supposedly it was left too close to a heater, yeah right.

Open it. If PCB is intact, then it might be too close to strong heater. But otherwise... smells like bullshit.

[QUOTE=ddrl46;50249403][t]http://i.imgur.com/9MK5epz.jpg[/t] Supposedly it was left too close to a heater, yeah right.[/QUOTE] Did they put it near a wood stove heater? That is the only thing i think that could cause it xD

[QUOTE=andreblue;50249531]Did they put it near a wood stove heater? That is the only thing i think that could cause it xD[/QUOTE] I wouldn't be surprised if it was mistakenly put on a barbecue for a while, the meter itself works fine so it just needs a new case. Separating the two halves of the case will be fun though since they are fused together :v:.

[QUOTE=ddrl46;50249852]I wouldn't be surprised if it was mistakenly put on a barbecue for a while, the meter itself works fine so it just needs a new case. Separating the two halves of the case will be fun though since they are fused together :v:.[/QUOTE] Hey, at least it works. Some multimeters can take a beating. I have a cheapo Mastercraft one that i put on a 12V car battery for volts, i forgot it was still plugged into the AMP plug. It still works. Only thing that happened was the fuse blew, the probes desoldered from the wires while still in my hands, and it smells like a ton of magic smoke. I would not thrus it for precision but it still works for quick volts, and resistance/continuity.

Turns out soldering TQFP-128 packages with thermal pads under them using hot air is even more difficult than I thought. I really need to just build a reflow oven and use solder paste, but I think I can try again and get it right on monday. [editline]4th May 2016[/editline] I managed to get the damn chip on before giving up, but it wound up at an angle, and heating the cooling pad under there is really fucking difficult, there's not enough thermal vias in the array to melt it from the bottom.

[QUOTE=Tobba;50256769]Turns out soldering TQFP-128 packages with thermal pads under them using hot air is even more difficult than I thought. I really need to just build a reflow oven and use solder paste, but I think I can try again and get it right on monday. [editline]4th May 2016[/editline] I managed to get the damn chip on before giving up, but it wound up at an angle, and heating the cooling pad under there is really fucking difficult, there's not enough thermal vias in the array to melt it from the bottom.[/QUOTE] Not sure what order you're soldering your components on, but try using an old cooking surface such as a griddle, flat hot-plate, or frying pan on a stove set to a warm temperature to pre-heat the PCB itself. Probably not a good idea for dual-sided boards though, but you could probably use an old crock-pot as well, so long as the elements work. As long as it can pre-heat the board you can use it to assist your current hot-air setup.

[QUOTE=Zero-Point;50265691]Not sure what order you're soldering your components on, but try using an old cooking surface such as a griddle, flat hot-plate, or frying pan on a stove set to a warm temperature to pre-heat the PCB itself. Probably not a good idea for dual-sided boards though, but you could probably use an old crock-pot as well, so long as the elements work. As long as it can pre-heat the board you can use it to assist your current hot-air setup.[/QUOTE] Cheap toaster oven works wonders also. Plus you can make toast while you solder! The toaster would also let you control the temp with more prescison and at worst, you can throw some sort of temp probe and make a PID loop to make it even better. 5$ for knock off arduino, + 5$ ish for a decent temp probe + 5$ for a triac + 35$ ish for the toaster oven and bam, cheap ass reflow oven for the cost of about 50$ to 75$ depending on the oven you get.

[quote]Cheap toaster oven works wonders also. [B]Plus you can make toast while you solder![/B][/quote] Most of us have already bumped 15 years off our lives with all the soldering we've done. That's a sure way to bump off an extra six months with every slice.

[QUOTE=Zero-Point;50265691]Not sure what order you're soldering your components on, but try using an old cooking surface such as a griddle, flat hot-plate, or frying pan on a stove set to a warm temperature to pre-heat the PCB itself. Probably not a good idea for dual-sided boards though, but you could probably use an old crock-pot as well, so long as the elements work. As long as it can pre-heat the board you can use it to assist your current hot-air setup.[/QUOTE] I smacked all the passives on first since I figured they're less heat sensitive and I'm pretty bad at this (it's dual-sided as well), but it's not like I can't take them off. I'm hoping I could probably just shove it on a hotplate with the whole bottom side on and hope too many of them don't fall off.

Doctors always tell us we're not taking in enough vitamins and minerals, surely a bit of lead won't do harm.

[QUOTE=nikomo;50271545]Doctors always tell us we're not taking in enough vitamins and minerals, surely a bit of lead won't do harm.[/QUOTE] Yeah, bone cancer sure sounds like a fine way to die.

[QUOTE=DrDevil;50271802]Yeah, bone cancer sure sounds like a fine way to die.[/QUOTE] With the lead, it will at least be fun if they decide to cremate you. You get to spread it around to the land if they spread you, and some into the air hehe.

[IMG]http://i11.photobucket.com/albums/a166/ballsandy/shipping.png[/IMG] Something doesn't seem right here....

Naw man, they're just selling you free shipping for $25. Capitalism!

[QUOTE=pentium;50276319][IMG]http://i11.photobucket.com/albums/a166/ballsandy/shipping.png[/IMG] Something doesn't seem right here....[/QUOTE] You're paying $25 for tighter tolerances!

I fucking wish I had Main and Lees in town. Fucking waiting a month for parts to arrive is brutal. I know you can email Main but my email keeps getting marked as spam and they don't get my orders. :v:

I found a soldering iron my grandpa built a few decades ago, along with what seems to be some ancient supplies [t]http://i.imgur.com/RSgmT42.jpg[/t] One says "lead-free" and the other one doesn't :O

[QUOTE=proboardslol;50278885]I found a soldering iron my grandpa built a few decades ago, along with what seems to be some ancient supplies [t]http://i.imgur.com/RSgmT42.jpg[/t] One says "lead-free" and the other one doesn't :O[/QUOTE] All of my solder is leaded. Even today leaded solder is the superior solder.