Electrical Engineering V2 - Developers

[QUOTE=Leestons;45395886]It sounds like you didn't limit the current and they went pop[/QUOTE] That's what I thought. Shame really, as it was one of the few displays I have salvaged that had solder holes large enough to use without some kind of high-tech machinery.

I presume continuity across all pins of a mosfet means it's dead, right?

I payed 9 euros for 2 10 LED bars only to find out later they are like 2 dollars a piece all over the web :x

Unless it's a normally-conducting type.

So my new Hexacopter is almost finished, I just need to mount the ESC's (needs a bit of soldering, that's why I am a little 'stuck') [IMG]https://dl.dropboxusercontent.com/u/100328/Facepunch/IMG_0665.JPG[/IMG] [IMG]https://dl.dropboxusercontent.com/u/100328/Facepunch/IMG_0669.JPG[/IMG] The build consists of: Frame: [URL="http://hobbyking.com/hobbyking/store/__23790__Turnigy_Talon_Hexcopter_V1_0_Carbon_Fiber_Frame_625mm.html"]Turnigy Talon Hexcopter (V1.0) Carbon Fiber Frame - 625mm[/URL] Additional mounting space: [URL="http://hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=42038"]Turnigy Talon V2 Carbon Fiber Main Top Plate[/URL] Flight Controller: [URL="http://www.quadcopters.co.uk/dji-naza-m-v2-flight-controller-inc-gps-721-p.asp"]DJI Naza M V2 Flight Controller Inc GPS[/URL] Bluetooth: [URL="http://www.quadcopters.co.uk/dji-naza-btu-907-p.asp"]DJI Naza BTU[/URL] 2x Battery: [URL="http://hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=38301"]ZIPPY Flightmax 8000mAh 4S1P 30C[/URL] (one onboard at a time) 6x ESC: [URL="http://hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=47789"]Turnigy Multistar 30 Amp Multi-rotor Brushless ESC 2-4S[/URL] 6x Props: [URL="http://hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=25820"]10x4.5 SF props[/URL] 6x Motors: [URL="http://hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=39959"]NTM Prop Drive Series 35-30 1100kv / 380w[/URL] I am going to be using my Spektrum DX6i, which sadly does not support Preset Failsafe, so i'll have to trust the Naza M-V2 to sense that no new inputs for a while means lost connection. Not ideal :(

Why are you stuck?

[QUOTE=Leestons;45402274]Why are you stuck?[/QUOTE] Because it is late (2:30 AM) and I won't be home in the next few days. But surely I'll head to the lab and fix it in the weekend :) I really want a GoPro Hero 3+ black and a Zenmuse 3D Gimbal to go with it. That's my next goal.

I'm looking at tutorials for DIY solar phone chargers and what strikes me with designs like this [url]http://www.instructables.com/id/Solar-Altoids-USB-Charger/?lang=de[/url] is that there is no prevention of the solar module overcharging the batteries. Does anyone know of a better tutorial?

[QUOTE=DrDevil;45401161]Unless it's a normally-conducting type.[/QUOTE] I think you mean a depletion mode MOSFET. They're not all that common though, usually you only see them in low power varieties in RF circuits where as standard JFET doesn't cut it. [QUOTE=Killuah;45405271]I'm looking at tutorials for DIY solar phone chargers and what strikes me with designs like this [url]http://www.instructables.com/id/Solar-Altoids-USB-Charger/?lang=de[/url] is that there is no prevention of the solar module overcharging the batteries. Does anyone know of a better tutorial?[/QUOTE] Smaller solar cells deliver piss-all current so protection isn't really needed, you also can't really over charge li-poly batteries since the current is self limited once the batteries reach a reasonable charge level.

I am so shit at soldering wires onto things. I have a solar panel that needs wires and I don't even want to try at the moment

[QUOTE=Chryseus;45406749]I think you mean a depletion mode MOSFET. They're not all that common though, usually you only see them in low power varieties in RF circuits where as standard JFET doesn't cut it. Smaller solar cells deliver piss-all current so protection isn't really needed, you also can't really over charge li-poly batteries since the current is self limited once the batteries reach a reasonable charge level.[/QUOTE] Normally-conducting is an acceptable term for them, and they're very common in current SiC technology.

This was a fairly standard, pretty high-power MOSFET so I assume I burnt it out when soldering or something. Ah well, time to buy more.

my TI chronos watch is here. It's quite nice and everything seems to work fine, with three exceptions: -the software that comes with it has an altitude display option which is like completely random :v: (uses a pressure sensor, but it goes to like 250 metres up while moving around a bit) -stopwatch has like 1/3rd of a second delay after pressing the button before it starts counting. -(not sure if watch or Spotify) you can connect the watch to some software which allows you to bind 3 buttons to a key on your computer, with the option of a 2nd key (for example P+ctrl). Tried using it for going to the next/previous song on Spotify but it didn't work with the correct keybindings.

[QUOTE=DrDevil;45401161]Unless it's a normally-conducting type.[/QUOTE] Not on a FET. The gate should never allow current to either of the other contacts on that type.

[QUOTE=Tamschi;45409460]Not on a FET. The gate should never allow current to either of the other contacts on that type.[/QUOTE] Of course, I misread that a little bit.

I'm so dumb. The previous owners of the house we moved into last year left a perfectly good workbench in the basement, maybe 12 feet from where my computer sits. And I completely forgot about it / didn't realize it was there. So, I moved all my shit onto it and threw together a PC from spare parts so I can look at schematics, google shit and program microcontrollers without getting shit all over my nice ultrabook. [T]http://i.imgur.com/2dGjCmw.jpg[/T]

I'm looking to make driver for a laser diode I ordered off of ebay. The description says it can handle up to 1.7A of constant current. So, I'm guessing I just need a constant current source to drive it? Assuming that is correct, can someone give me some insight as to how to make a constant current source with say a 5V or 12V DC source? I'm a bit of a novice, so I haven't learned how to do this quite yet.

[QUOTE=Splash Attack;45413593]I'm looking to make driver for a laser diode I ordered off of ebay. The description says it can handle up to 1.7A of constant current. So, I'm guessing I just need a constant current source to drive it? Assuming that is correct, can someone give me some insight as to how to make a constant current source with say a 5V or 12V DC source? I'm a bit of a novice, so I haven't learned how to do this quite yet.[/QUOTE] The easiest way to do that is using a linear regulator like the LM317 in this configuration: [img]http://upload.wikimedia.org/wikipedia/commons/4/4f/LM317_1A_ConstCurrent.svg[/img] The linear regulator tries everything to keep the voltage on the Adj pin at 1.25V below the output voltage. If the voltage dips below that, it increases the output voltage. If it grows larger than that, it lowers the output voltage. Now we cleverly use Ohm's law ( R = U/I ). As the current flows through the resistor, a voltage drops over it. The voltage drop is proportional to the current, so you can calculate the resistance you need to make it output 1.7A. Given the equation R = U/I, you pluck in both U and I. U is 1.25V, since ADJ has to be 1.25 below the output. I is 1.7A, since that is the current you want to set. You need a resistor of 0.735 Ohm.

[QUOTE=Splash Attack;45413593]I'm looking to make driver for a laser diode I ordered off of ebay. The description says it can handle up to 1.7A of constant current. So, I'm guessing I just need a constant current source to drive it? Assuming that is correct, can someone give me some insight as to how to make a constant current source with say a 5V or 12V DC source? I'm a bit of a novice, so I haven't learned how to do this quite yet.[/QUOTE] If 1.5A will do [IMG]http://users.telenet.be/davshomepage/bitmaps/curreg.jpg[/IMG] Iout=1.25/R Of course you'll need an input a little more than the output [editline]17th July 2014[/editline] 2 minutes? Fuck. Explained so much better though.

is a gas soldering iron any good or are they just crap as long as you can use a normal one in your location.

Only good for places where you can't use a proper soldering iron. Like in a car for example.

Don't use them, they're really for emergency purposes.

They're handy for shrinking heat-shrink tube and can be used to remove surface mount components (most come with an adapter for using it as a mini blowtorch)

They're great when you're say outside working on your bike/car/whatever and when you need a LOT of power.

[QUOTE=Chryseus;45416399]They're handy for shrinking heat-shrink tube and can be used to remove surface mount components (most come with an adapter for using it as a mini blowtorch)[/QUOTE] I just use my hot air rework station for that.

[media]http://www.youtube.com/watch?v=7uVmt2b3NyY[/media] Holy shit.... God damn Russians. always make the best stuff.

That echo is fantastic, great location too. Now I want to see how beefy those IGBTs were.

[QUOTE=LoneWolf_Recon;45419407]That echo is fantastic, great location too. Now I want to see how beefy those IGBTs were.[/QUOTE] About the same size as ones i posted up on the thead, just a higher rating. Each of those igbts are single bricks capable of 1200V 1200A, same package as my own ones. However my ones have 2 IGBTs inside them, each rated at 1700V @ 800A. If i wanted, i could use 6 of these modules, if i could find a suitable powersource and suitable rest of the components, i could build an even bigger one i do believe. And to be honest, i do want to... but moneys.

How much does one of those cost?

[QUOTE=Cakebatyr;45420731]How much does one of those cost?[/QUOTE] The IGBTs? mine were around £700 each. i have a contact in the wind industry that gets them for me for free (usually when i buy somthing else off him or whatnot)