Electrical Engineering V2

[nikomo]

Got my board done.
[t]http://i.imgur.com/sRZfA6k.jpg[/t]

The room where like 90% of our SMD resistors are stored is serving as locked storage for like 50k € worth of computer equipment, until we assemble them tomorrow, and I couldn't be bothered to wait until tomorrow, so I got creative in places.

[t]http://i.imgur.com/tihwnQU.jpg[/t]

After I took that picture, I added a 10K between 5V and OE.
Need to test the board now. Haven't written any code for it yet.
Also, I apparently forgot to add a trace between the collector of the transistor for the blue part of my RGB LED. Oops. Fixed it with wire, in hindsight the leg of a resistor would have been better, I'll probably change it at some point.

[Tamschi]

[QUOTE=pentium;46170839]Got a weird issue going on here.

I need to replace some resistors but I don't have matching components both in rating and wattage.
To make a 2.2K 1/2W resistor I took two 2.2k 1/4W resistors and put them in parallel. To make a 33k 1/2W I took a 22k, a 10k and a 1k in series and tied a second set in parallel.

In both cases the value of the substitute was half. The new 2.2k was 1.1k and the new 33k was 16.5K.[/QUOTE]

Parallel resistors:

[IMG]http://latex.codecogs.com/gif.latex?R%20%3D%20%5Cfrac%7B1%7D%7B%5Csum_n%5Cfrac%7B1%7D%7BR_n%7D%7D[/IMG]

[pentium]

[QUOTE=Tamschi;46173350]Parallel resistors:

SCIENCE, BITCHES[/QUOTE]

Why is electronics so complicated?

[nikomo]

Did you guys know that some pins on a standard IDE cable are intentionally connected to each other?
So if you happened to, oh, for some reason use one to connect a board to a Raspberry Pi, the Pi would just shut down and refuse to start up, because of a short circuit.

So, an IDE cable is completely unsuited for connecting my board to a Pi.
Going to have to see if school has standard parallel cable tomorrow. But I have Dupont female-female cables at home I can use in the meanwhile.

[pentium]

[QUOTE=nikomo;46174184]Did you guys know that some pins on a standard IDE cable are intentionally connected to each other?
So if you happened to, oh, for some reason use one to connect a board to a Raspberry Pi, the Pi would just shut down and refuse to start up, because of a short circuit.

So, an IDE cable is completely unsuited for connecting my board to a Pi.
Going to have to see if school has standard parallel cable tomorrow. But I have Dupont female-female cables at home I can use in the meanwhile.[/QUOTE]

The fuck kind of cable are you using? 80 wire ATA or the older 40 wire IDE? They shouldn't be wired together in the cable itself.

40 wire should work as-is.
[img]http://www.arduinopassion.com/wp-content/uploads/2013/01/raspberry-pi-like-arduino.jpg[/img]

[nikomo]

I just read up on it.

I was using 80-wire ATA, some of the cables are connected to a ground pin, which was causing my problems.
40-wire IDE should be fine.

Too bad I haven't seen one of those since the dinosaurs died.

[pentium]

If you were closer I'd give you one. I got a box of them.

[nikomo]

[t]http://i.imgur.com/Oe8DIDi.png[/t]

Button works.
Now to test RGB LED and segment display.
Segment display is so going to have to wait until tomorrow, too tired to think about the shift register right now.

[Zero-Point]

[QUOTE=nikomo;46174478]I just read up on it.

I was using 80-wire ATA, some of the cables are connected to a ground pin, which was causing my problems.
40-wire IDE should be fine.

Too bad I haven't seen one of those since the dinosaurs died.[/QUOTE]

Every other wire in an 80-wire IDE is just a ground and they're all connected to minimize noise/cross-talk. Just figure out which ones are ground and which ones aren't and you're good to go.

[Cakebatyr]

[QUOTE=pentium;46174493]If you were closer I'd give you one. I got a box of them.[/QUOTE]

When you're next in Vancouver I'll take that box.

[pentium]

[QUOTE=Cakebatyr;46176148]When you're next in Vancouver I'll take that box.[/QUOTE]

Head over to FreeGeek. They'll sell you all the bulk ribbon cable and electronic junk you can carry for next to free. It's where I got all mine.

Also, I see my blunder now. If I wanted to make a 1/2 watt 33K resistor I should of used two pairs of 1/4w resistor sets equalling 66K each, right?

[Metallics]

[QUOTE=pentium;46179355]Head over to FreeGeek. They'll sell you all the bulk ribbon cable and electronic junk you can carry for next to free. It's where I got all mine.

Also, I see my blunder now. If I wanted to make a 1/2 watt 33K resistor I should of used two pairs of 1/4w resistor sets equalling 66K each, right?[/QUOTE]

Yes. How are you so good at repairing old electronics yet basic resistor theory is not a thing for you?

[pentium]

I generally don't kludge and when I do I have no idea what I am doing and fall off a fucking cliff. :v:

[Ddrl46]

Ran a calibration on that Fluke 187 I showed a few posts earlier, not bad.

[url=http://i.imgur.com/fyVk1Be.jpg][img]http://i.imgur.com/fyVk1Bel.jpg[/img][/url]

[TCWilliamson]

Trying to sell off a large load of capacitors. Deals here:
[url]http://www.eevblog.com/forum/buysellwanted/large-capacitor-modules-for-sale-(uk)[/url]

- Arranged for 5 sets of 3 in series for a total of 2500uF @ 1350V
- Professionally laminated plates for low inductance.
- Stainless Steel bracket holding them together, the entire module is able to be bolted down.
- Balancing & Bleeder resistors built in.
- Laminated Tinned copper plate.

[URL=http://imgur.com/Eba79pF][IMG]http://i.imgur.com/Eba79pFs.jpg[/img][/URL][URL=http://imgur.com/X2ujP4I][IMG]http://i.imgur.com/X2ujP4Is.jpg[/img][/URL][URL=http://imgur.com/qhApghV][IMG]http://i.imgur.com/qhApghVs.jpg[/img][/URL][URL=http://imgur.com/RnTn0IZ][IMG]http://i.imgur.com/RnTn0IZs.jpg[/img][/URL]
[URL=http://imgur.com/54A2AKh][IMG]http://i.imgur.com/54A2AKhs.jpg[/img][/URL][URL=http://imgur.com/SieRXsU][IMG]http://i.imgur.com/SieRXsUs.jpg[/img][/URL][URL=http://imgur.com/Z480BQy][IMG]http://i.imgur.com/Z480BQys.jpg[/img][/URL][URL=http://imgur.com/exGi3C4][IMG]http://i.imgur.com/exGi3C4s.jpg[/img][/URL]

Just PM me on there or on here ;)

[LoneWolf_Recon]

[QUOTE=nuttyboffin;46186308]Trying to sell off a large load of capacitors. Deals here:
[url]http://www.eevblog.com/forum/buysellwanted/large-capacitor-modules-for-sale-(uk)[/url]

- Arranged for 5 sets of 3 in series for a total of 2500uF @ 1350V
- Professionally laminated plates for low inductance.
- Stainless Steel bracket holding them together, the entire module is able to be bolted down.
- Balancing & Bleeder resistors built in.
- Laminated Tinned copper plate.

[URL=http://imgur.com/Eba79pF][IMG]http://i.imgur.com/Eba79pFs.jpg[/img][/URL][URL=http://imgur.com/X2ujP4I][IMG]http://i.imgur.com/X2ujP4Is.jpg[/img][/URL][URL=http://imgur.com/qhApghV][IMG]http://i.imgur.com/qhApghVs.jpg[/img][/URL][URL=http://imgur.com/RnTn0IZ][IMG]http://i.imgur.com/RnTn0IZs.jpg[/img][/URL]
[URL=http://imgur.com/54A2AKh][IMG]http://i.imgur.com/54A2AKhs.jpg[/img][/URL][URL=http://imgur.com/SieRXsU][IMG]http://i.imgur.com/SieRXsUs.jpg[/img][/URL][URL=http://imgur.com/Z480BQy][IMG]http://i.imgur.com/Z480BQys.jpg[/img][/URL][URL=http://imgur.com/exGi3C4][IMG]http://i.imgur.com/exGi3C4s.jpg[/img][/URL]

Just PM me on there or on here ;)[/QUOTE]

You've got the part no, datasheets for those caps?

[TCWilliamson]

[QUOTE=LoneWolf_Recon;46186971]You've got the part no, datasheets for those caps?[/QUOTE]

Afraid not, however they are each values at 450V @ 1500uF i believe they are 17A Ripple each. They are good quality caps since they are designed for use in Inverters.

[DrLuke]

Yeah when selling those caps you should definitely insist on some kind of verification that the buyer is over 18, otherwise you might get into enormous trouble if some kid decides to blow off their arm with it.

[Chryseus]

[QUOTE=DrDevil;46189608]Yeah when selling those caps you should definitely insist on some kind of verification that the buyer is over 18, otherwise you might get into enormous trouble if some kid decides to blow off their arm with it.[/QUOTE]

They would fully deserve it for being retarded enough for that to actually happen.

[TCWilliamson]

[QUOTE=DrDevil;46189608]Yeah when selling those caps you should definitely insist on some kind of verification that the buyer is over 18, otherwise you might get into enormous trouble if some kid decides to blow off their arm with it.[/QUOTE]

I dissagree, Capacitors in many cases, around mains voltage, are safer then a mains line, this is because a capacitor generally isn't grounded, you have to touch both sides to get the shock. While it can discharge much more current at a time, you sitll need to touch both sides, whereas a mains line, you just need to touch live and earth or neutral.

[DrLuke]

It's more of a liability thing. You know how people are these days.

[TCWilliamson]

[QUOTE=DrDevil;46191667]It's more of a liability thing. You know how people are these days.[/QUOTE]

Thats true.

Still need to sell them soon .-.

I actually got given a load when i was like.... 14? haha

Might be willing to drop the price down more. i really need to sell these bloody things.

[Cakebatyr]

[t]http://u.limonene.net/IMG_20141009_131524.jpg[/t]

Awww yeah chinese wifi/generic radio modules arrived. Anti-static bags are the ESP8826's, the styrofoam block is a bunch of NRF24L01+'s

Also my SDR was in the mail as well.

[Leestons]

I was going to get one of those supercaps but then realised it's useless to me other than blowing shit up so I think I'll get a couple of the smaller ones.

[TCWilliamson]

[QUOTE=Leestons;46193725]I was going to get one of those supercaps but then realised it's useless to me other than blowing shit up so I think I'll get a couple of the smaller ones.[/QUOTE]

Your really need to buy my capacitors. THEY WILL CHANGE YOUR WORLD. THEY WILL MAKE YOU AMAZING

[MetricMoose]

[QUOTE=Cakebatyr;46193711][t]http://u.limonene.net/IMG_20141009_131524.jpg[/t]

Awww yeah chinese wifi/generic radio modules arrived. Anti-static bags are the ESP8826's, the styrofoam block is a bunch of NRF24L01+'s

Also my SDR was in the mail as well.[/QUOTE]

I've had no luck getting my ESP8266s going, I just get no response to any commands.

[pentium]

Chryseus will agree with me.

Analog electronics are a black art.

[Cakebatyr]

[QUOTE=benjgvps;46194827]I've had no luck getting my ESP8266s going, I just get no response to any commands.[/QUOTE]

What were you connecting them to?

The datasheets say they run at 3.3V and Arduino's (for the most part) are 5V boards.

I plan to throw [url=http://www.adafruit.com/products/1875]one of these[/url] between the two boards.

[MetricMoose]

[QUOTE=Cakebatyr;46195370]What were you connecting them to?

The datasheets say they run at 3.3V and Arduino's (for the most part) are 5V boards.

I plan to throw [url=http://www.adafruit.com/products/1875]one of these[/url] between the two boards.[/QUOTE]

I've seen a bunch of examples running them off Arduinos directly. I have some of these: [url]http://www.ebay.ca/itm/310993174471?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649[/url]

Though I hooked them up according to the sparkfun serial example and the power LED doesn't even come on. If I recall, I barely got two volts when I measured the power pins.

[jaooe]

what would it take to detect metal within a quarter mile radius? and what would be the dangers of this in real life use??? :O