Electrical Engineering V2

[ben1066]

[IMG_THUMB]http://i.imgur.com/x6PgNXG.jpg[/IMG_THUMB]
New stuff, though I don't have a high enough voltage supply for them currently.

[Leestons]

What voltage does it need?

[ben1066]

[QUOTE=Leestons;45826019]What voltage does it need?[/QUOTE]

I think 20V and I've seen the max voltage as 36V (for PWM type operation). I however lack a proper bench supply (pretty high on my list of must get stuff). I'm getting some SMPS module thingy that I can hook up to try and drive them for now. I may as well ask, any suggestions for a bench supply that'll go to say 30V+?

[No_Excuses]

The owner of the local Radioshack/Source gave me his amplifier to repair. Some odd brand called Crate Audio. Claims 800W/ch into 8 ohms I believe. The story goes it was being used by his band outdoors and it started raining and something blew. They had the tech guy at the Radioshack look at it and he replaced a couple components which didn't seem to fix the problem.

I dug into it today and found out he replaced a pair of thermistors for inrush current limiting with a pair of varistors....

All I can say is they're lucky it wasn't the other way around. Coulda been full line voltage straight to ground.

[TCWilliamson]

I have finally finished off my variac case with all buttons and remote control.

[media]http://www.youtube.com/watch?v=jDq7_aPGfK0[/media]

[LoneWolf_Recon]

Fantastic, love the professionalism. How many amps can it crank out?

[Nikita]

Do you guys know those "USB lamps" and "USB cup holders" and such?

What are you supposed to plug them into? My computer just goes "port X is consuming too much power and has been disabled".

[Gulen]

Wall adapters?

[TCWilliamson]

[QUOTE=LoneWolf_Recon;45830252]Fantastic, love the professionalism. How many amps can it crank out?[/QUOTE]

The variac is good for 32A however i have seen people take these ones past 70A for short periods.

[DrLuke]

[QUOTE=Nikita;45832604]Do you guys know those "USB lamps" and "USB cup holders" and such?

What are you supposed to plug them into? My computer just goes "port X is consuming too much power and has been disabled".[/QUOTE]

[QUOTE=nuttyboffin;45833637]The variac is good for 32A however i have seen people take these ones past 70A for short periods.[/QUOTE]

There you go!

[Hng]

[t]http://puu.sh/bcG3E/7394fb137d.png[/t]

:D

[editline]29th August 2014[/editline]

[QUOTE=ollie;45327399][URL]https://www.windowsondevices.com[/URL]
Microsoft are giving out testing samples of development boards, I'd suggest checking it out if you are interested.[/QUOTE]

Original post that informed me of the boards. Anyone else get confirmation? Looks like they're still accepting signups BTW.

[url]https://www.windowsondevices.com/signup.aspx[/url]

[Fourier]

[QUOTE=Hng;45834548][t]http://puu.sh/bcG3E/7394fb137d.png[/t]

:D

[editline]29th August 2014[/editline]

Original post that informed me of the boards. Anyone else get confirmation? Looks like they're still accepting signups BTW.

[url]https://www.windowsondevices.com/signup.aspx[/url][/QUOTE]

Good job! :D

[pentium]

[QUOTE=nuttyboffin;45828389]I have finally finished off my variac case with all buttons and remote control.

[media]http://www.youtube.com/watch?v=jDq7_aPGfK0[/media][/QUOTE]

*click* *clunk* *click* *clunk*

[kolobok]

Oh guys, I'm so excited! I've just bought a couple of AVRs' microcontrollers, resistors, capacitors, LEDs and other things. Also, bought LPT+COM port.
Can't wait to start making something useful :)
[QUOTE][IMG]http://i.imgur.com/e2Ond9Z.jpg[/IMG][/QUOTE]

[Leestons]

Keep us updated!

[Ddrl46]

[QUOTE=kolobok;45837094]Oh guys, I'm so excited! I've just bought a couple of AVRs' microcontrollers, resistors, capacitors, LEDs and other things. Also, bought LPT+COM port.
Can't wait to start making something useful :)[/QUOTE]

Do you also have a breadboard? Bit of a pain in the ass to constantly have to solder everything you want to test.

[kolobok]

[QUOTE=ddrl46;45837615]Do you also have a breadboard? Bit of a pain in the ass to constantly have to solder everything you want to test.[/QUOTE]

Actually, I wanted to buy it at first. But in the beginning of this year I've bought soldering station...and that's all. I mean, I haven't used it yet. So, I find soldering process so beautiful and interesting and that's why I haven't bought breadboard.
By the way, gonna buy it soon.

[TCWilliamson]

[QUOTE=pentium;45836527]*click* *clunk* *click* *clunk*[/QUOTE]

The best sound is the sound that happens in the second stage, when power is connected to the variac. As you can probibly imagine, the sound from the variac magnatising is.... awesome. let me find a transformer with a similar sound:
[media]http://www.youtube.com/watch?v=f_jhlHp7bGk[/media]

[Cakebatyr]

That's no transformer, that's a tripod.

Also iI ordered a bunch of 0.1uF capacitors instead of 10uF ones... woops.

[Leestons]

[QUOTE=Cakebatyr;45840529]That's no transformer, that's a tripod.

Also iI ordered a bunch of 0.1uF capacitors instead of 10uF ones... woops.[/QUOTE]

Just stick 100 in parallel :v:

[Kirth]

Found a 0.75A fuse in a 1A rated circuit. The glow it produces is beautiful, much like a swan's song.

[LuaStoned]

[QUOTE=DrDevil;45815639]If you can get ahold of register maps (datasheet?) you could probably directly drive the spi registers.[/QUOTE]

I actually found something from TI: [url=http://processors.wiki.ti.com/index.php/StarterWare]StarterWare[/url]

Here's what I came up with (it works every 2nd or 3rd time.. weird right?)

int spiWrite(uint8_t *tx, uint32_t length)
{
	// cs line is forced to low state.
	McSPICSAssert(spi, chNum);

	// enable the spi channel for communication.
	McSPIChannelEnable(spi, chNum);

	while (length > 0)
	{
		McSPITransmitData(spi, (unsigned int)(*tx++), chNum);
		length--;
		
		unsigned int rx = McSPIReceiveData(spi, chNum);
	}

	// force cs line to the inactive state.
	McSPICSDeAssert(spi, chNum);

	// Disable the spi channel.
	McSPIChannelDisable(spi, chNum);	
}

There is more info about it here: [url=http://processors.wiki.ti.com/index.php/StarterWare_McSPI]StarterWare SPI[/url]
Not sure if the interrupt or DMA mode would work better than this?

[r0b0tsquid]

The bad news is that I just shorted the output capacitance of my power supply at 35V across my (homebrew) multimeter's current input, heard a bang, and it stopped working.

The good news is that that was just the sound of the protection fuse doing its job!

[r0b0tsquid]

I've done a massive [URL="http://wrenstech.wordpress.com/2014/08/31/measure-all-the-things/"]blog post[/URL] on how I'm measuring V, I and C with my multimeter!

The analogue side of things is super basic but it goes into things like why you can get 12 bits of precision out of a 10 bit ADC, and using the analogue comparator to make capacitance measurements from 1nF to 700uF, with all of the code.

Some of you guys might find it interesting :)

[editline]1st September 2014[/editline]

[img]http://i.imgur.com/qO3M4CA.png[/img]

I guess this works too now... :v:

EX330 flicks between 99.7kOhm and 99.8kOhm, so safe to say it's pretty accurate!

[DrLuke]

Why are you calling the AVR datasheet terrible? It's actually one of the better datasheets out there.

[r0b0tsquid]

[QUOTE=DrDevil;45858892]Why are you calling the AVR datasheet terrible? It's actually one of the better datasheets out there.[/QUOTE]

"Terrible" means something more like "fearsome" in that context. I actually have no problems with it!

[Editline]blah[/editline]

I should probably add a note to clear that up...

[RoflKawpter]

I'm so frustrated because I have no clue what I'm doing wrong...

I'm following this code from this page

[url]http://arduino.cc/en/tutorial/button[/url]
with the exception of changing ButtonPin to '6' (D3 on this pinout diagram - [url]https://encrypted-tbn1.gstatic.com/images?q=tbn:ANd9GcS7KuzGxA90t2L9-mUBsQVoLibjCGV9IyFCQd1jvlx8a1CI6a9u[/url] )

This is what I have on my breadboard:

[url]https://www.dropbox.com/s/ctpggti1uwpywg3/2014-09-01%2017.47.43.jpg?dl=0[/url]

I really REALLY don't know whats going on. I push the button and the LED doesn't light up. I know Pin 13 lights up cause the 'blink' sketch works, and I know the button works, cause I tested it with my multimeter.

It's so frustrating when I want to get stuff done but you get stuck and you have NO clue what to do....

Help? :P

[Papkee]

[QUOTE=RoflKawpter;45866231]I'm so frustrated because I have no clue what I'm doing wrong...

I'm following this code from this page

[url]http://arduino.cc/en/tutorial/button[/url]
with the exception of changing ButtonPin to '6' (D3 on this pinout diagram - [url]https://encrypted-tbn1.gstatic.com/images?q=tbn:ANd9GcS7KuzGxA90t2L9-mUBsQVoLibjCGV9IyFCQd1jvlx8a1CI6a9u[/url] )

This is what I have on my breadboard:

[url]https://www.dropbox.com/s/ctpggti1uwpywg3/2014-09-01%2017.47.43.jpg?dl=0[/url]

I really REALLY don't know whats going on. I push the button and the LED doesn't light up. I know Pin 13 lights up cause the 'blink' sketch works, and I know the button works, cause I tested it with my multimeter.

It's so frustrating when I want to get stuff done but you get stuck and you have NO clue what to do....

Help? :P[/QUOTE]

Are you sure on your arduino that D3 is reffered to by pin 6? It seems like if it's called D3 it would be referred to as pin 3 in code, just as in a normal arduino.

[RoflKawpter]

[QUOTE=papkee;45866701]Are you sure on your arduino that D3 is reffered to by pin 6? It seems like if it's called D3 it would be referred to as pin 3 in code, just as in a normal arduino.[/QUOTE]
It works. Really. Why the hell would that pin out diagram be different? D:

[Zero-Point]

So I was asked to look at a tablet for a friend of mine, said it wouldn't charge by USB.
Took it apart and the USB connector had somehow sheared clean off of its spot, no pins or traces damaged or broken at all, how the fuck?
Anyway so I re-soldered the thing back on and- I'm not sure of the industry term for this package, but the mini-USB SMD connectors, with the REALLY short and tiny itty bitty little pins? Pain in the ass to do with a Radioshack soldering station, lemme tell ya. :v: