[T]http://u.limonene.net/IMG_20150122_133451.jpg[/t]
I sure hope my crossed dipole works.
[QUOTE=Th3applek1d;46989447]So i'm absolutely terrified of soldering and stuff, because I have super shaky hands and get migraines super easily from straining my eyes and concentrating on things really hard, and my Arduino is on the way. Is there going to be a point where I am gonna have to solder? I'm buying all my stuff with heads already on it, but what else do I have to solder for?[/QUOTE]
Why don't you just give it a try? Soldering is fun, and Through-Hole stuff works perfectly with shaky hands.
Jim Williams used to shake like mad so you should have no problems.
I've been needing an AM modulator for a while, so I decided to design something decent:
[img]http://u.cubeupload.com/Chryseus/bw8Pov.png[/img]
This doesn't include the RF generator since I already have one, well at least up to 20MHz, I might do a 1kHz tone generator though, maybe a wien bridge.
I know I could have used an op-amp at these frequencies but that's no fun, this should work up to hundreds of MHz depending on the transistors.
I found a really cool OLED display that would fit perfectly into a project of mine, it's manufactured by a company called EastRising in China.
I spent about an hour trying to find the pinouts for the flat flex cable that it has.
It's hidden in a little sideways table in a mechnical drawing, in their display module datasheet, instead of the controller datasheet (what the cable is actually connected to), or the connector datasheet (the actual cable).
Not my photo, but I got to play around in this place today. Had free reign on anything I wanted to take as they're tearing the place down.
[t]http://scontent-b.cdninstagram.com/hphotos-xpa1/t51.2885-15/e15/927869_1425208701053412_692391043_n.jpg[/t]
I've got a few pics but I was more concerned with taking as much shit as I could carry. Will update with my cools finds later.
I hope you took all the dials.
[editline]26th January 2015[/editline]
Also I've recalibrated my scanner to see if I can pick up SAUDISAT SO-50 in the next 20 hours.
[QUOTE=Cakebatyr;47011956]I hope you took all the dials.
[/QUOTE]
The problem was each dial weighs about 20 pounds and I had to carry everything out on foot, so coupled with about 80 pounds of other goodies I couldn't take more than two. I got the best ones though, one shows the total plant output in Megawatts and the other shows KV.
[QUOTE=papkee;47012947]The problem was each dial weighs about 20 pounds and I had to carry everything out on foot, so coupled with about 80 pounds of other goodies I couldn't take more than two. I got the best ones though, one shows the total plant output in Megawatts and the other shows KV.[/QUOTE]
Sweet, now all you need is something that outputs megawatts!
[QUOTE=papkee;47011245]Not my photo, but I got to play around in this place today. Had free reign on anything I wanted to take as they're tearing the place down.
[t]http://scontent-b.cdninstagram.com/hphotos-xpa1/t51.2885-15/e15/927869_1425208701053412_692391043_n.jpg[/t]
I've got a few pics but I was more concerned with taking as much shit as I could carry. Will update with my cools finds later.[/QUOTE]
You lucky bastard.
I'd take all LCDs I would be able to, and more
If I could I'd take the lot and worry about storage later.
This was the back of the truck when we were done, it was empty when we started.
[t]http://i.imgur.com/FaJWSst.jpg[/t]
It's the second time I've been. The first time was when I got all those relays and a bunch of GE nameplates.
And a box with a ton of buttons on it. I love industrial buttons.
oh my god I just had a massive orgasm
I found a toner transfer test pattern online and have been trying to see what the smallest traces I can get are. I refined my toner transfer process and am getting constant 10 mil traces without any holes. I can get 8 mil traces about half of the time with careful cleaning and sanding. My 5 mil traces haven't ever come out completely without holes but are easily fixed with a marker. Going down to 2 mil I am limited by the printer resolution but the dots it manages to put down stick so with a higher resolution printer I think i could go smaller.
This is all before etching however, we will see how these small traces fare the acid.
Unfortunately I have no clue how to supply this thing with 72V @ 8A but it looks cool as hell.
[t]http://i.imgur.com/T7z3ste.jpg[/t]
Serial number has it as being manufactured in the 30's.
[QUOTE=Dolton;47016421]I found a toner transfer test pattern online and have been trying to see what the smallest traces I can get are. I refined my toner transfer process and am getting constant 10 mil traces without any holes. I can get 8 mil traces about half of the time with careful cleaning and sanding. My 5 mil traces haven't ever come out completely without holes but are easily fixed with a marker. Going down to 2 mil I am limited by the printer resolution but the dots it manages to put down stick so with a higher resolution printer I think i could go smaller.
This is all before etching however, we will see how these small traces fare the acid.[/QUOTE]
Success! After etching the 8 mil traces came out perfectly!
The 5 mil traces also survived but had one hole from where the toner came off during the transfer.
1 mil traces mostly gone but remains in some places. Even with a higher resolution printer 1 mil is probably out of reach but 5mil is easily doable.
I ordered a Saleae Logic knock-off on eBay some time ago, it arrived today.
I was wondering if Debian already had the software readily packaged, had a quick search, and accidentally ran into a free software project named Sigrok.
Turns out they wrote a free software firmware that works with both the original Saleae Logic, and the knock-off I just bought. I gave it a try, successfully captured UART traffic at 115200 baud from my Arduino Uno.
[URL]http://sigrok.org/wiki/MCU123_Saleae_Logic_clone[/URL]
So, I basically accidentally bought a FOSS logic analyzer for less than 7€ on eBay.
I'd have been happy with the proprietary vendor software, but hey, this just makes me extremely happy.
(And yes, I took it apart before turning it on, just to make sure it wouldn't blow up my laptop)
[editline]27th January 2015[/editline]
The logic analyzer works on Android over USB OTG.
[img]http://i.imgur.com/Q7uCfAC.png[/img]
The UI is clunky, but it's a 7€ logic analyzer that you can throw in your bag, and it works with your phone.
[img]http://assets.cambridge.org/97805218/09269/cover/9780521809269.jpg[/img]
Art of Electronics 3rd edition is out in April.
[url]http://www.cambridge.org/us/academic/subjects/physics/electronics-physicists/art-electronics-3rd-edition[/url]
Hey guys,
Looking for a bit of an explanation regarding the more physics side of Diodes rather than the Electronics, I spoke to Ddrl46 about it but he had to go.
For a piece of Physics coursework, I attempted to measure the turn on voltage for a diode, I set up a simple circuit with a variable bench power supply, the diode, an ammeter and two voltmeters in paralell to the power supply (to measure true output) and the diode. I got what I think is a [URL="http://puu.sh/f7f6J.png"]good set of results[/URL] showing the rise in current as voltage increases.
I now need to explain the background physics behind the whole experiment, but i'm having a bit of trouble doing so, in particular explaining why this behavior happens when the voltage is increased past a certain point - anybody able to lend a hand?
[QUOTE=Dorkslayz;47022929]Hey guys,
Looking for a bit of an explanation regarding the more physics side of Diodes rather than the Electronics, I spoke to Ddrl46 about it but he had to go.
For a piece of Physics coursework, I attempted to measure the turn on voltage for a diode, I set up a simple circuit with a variable bench power supply, the diode, an ammeter and two voltmeters in paralell to the power supply (to measure true output) and the diode. I got what I think is a [URL="http://puu.sh/f7f6J.png"]good set of results[/URL] showing the rise in current as voltage increases.
I now need to explain the background physics behind the whole experiment, but i'm having a bit of trouble doing so, in particular explaining why this behavior happens when the voltage is increased past a certain point - anybody able to lend a hand?[/QUOTE]
[t]http://ecee.colorado.edu/~bart/book/book/chapter4/gif/fig4_2_3.gif[/t]
An unbiased diode has a potential barrier between the P and N type semiconductor caused by the different energy levels of the semiconductor, in N type semiconductor the conduction band is shifted down whereas in P type material it is shifted up relative to the fermi level, as a result an electron in the N type material cannot gain enough energy to cross in to the P type conduction band.
As the diode is forward biased the energy difference between the P and N type material drops which exponentially allows more electrons to cross from the N type material in to the P type material, this can be calculated using the shockley diode equation:
ID = IS ( exp(Vd / n*Vt) - 1 )
Where:
ID = Diode current
IS = Saturation current (10pA typ)
Vd = Diode voltage
n = Ideality factor (1 to 2)
Vt = Thermal voltage (kT / q)
or in the case of voltage:
VD = n * Vt * ln( ID / IS + 1)
If you want to know more I suggest reading Semiconductor Physics and Devices by Donald Neamen, although it may make you commit suicide after the first chapter.
Another one of the grabs from the power plant.
[t]http://i.imgur.com/MghlrVF.jpg[/t]
I like it when my buttons are rated for 440volts and 20 amps.
[QUOTE=Chryseus;47024092][t]http://ecee.colorado.edu/~bart/book/book/chapter4/gif/fig4_2_3.gif[/t]
An unbiased diode has a potential barrier between the P and N type semiconductor caused by the different energy levels of the semiconductor, in N type semiconductor the conduction band is shifted down whereas in P type material it is shifted up relative to the fermi level, as a result an electron in the N type material cannot gain enough energy to cross in to the P type conduction band.
As the diode is forward biased the energy difference between the P and N type material drops which exponentially allows more electrons to cross from the N type material in to the P type material, this can be calculated using the shockley diode equation:
ID = IS ( exp(Vd / n*Vt) - 1 )
Where:
ID = Diode current
IS = Saturation current (10pA typ)
Vd = Diode voltage
n = Ideality factor (1 to 2)
Vt = Thermal voltage (kT / q)
or in the case of voltage:
VD = n * Vt * ln( ID / IS + 1)
If you want to know more I suggest reading Semiconductor Physics and Devices by Donald Neamen, although it may make you commit suicide after the first chapter.[/QUOTE]
To append to that, typically Silicon based semiconductors have a Thermal voltage of ~25.8mV @ 300K. I'd recommend Microelectronic Circuit Design by Jaeger & Blalock, great book that jumps right in and is pretty fair on the Junction physics.
If you'd like to find the depletion layer width when unbiased:
w_depletion = sqrt( ((2*E_r*E_o)/q) * ((1/N_A) + (1/N_D)) * Phi_j )
Where:
E_r - Relative permittivity of base material (Silicon is 11.7)
E_o - Vacuum permittivity (8.85 x 10^-14 F/cm)
q - Charge of current carriers(holes/electrons): 1.602 x 10^-19 C
N_A - Acceptor Dopant Concentration (In cm^-3)
N_D - Donor Dopant Concentration (In cm^-3)
Phi_j - Internal/Built-in Potential of Junction Provided by lower equation:
Phi_j = Vt * ln( (N_A * N_D) / (n_i^2) )
Where n_i is the intrinsic carrier concentration of the base material (For 99.9% Pure Silicon n_i = 6.7 x 10^9 cm^-3 @ 300K).
[QUOTE=Chryseus;47022609][IMG]http://assets.cambridge.org/97805218/09269/cover/9780521809269.jpg[/IMG]
Art of Electronics 3rd edition is out in April.
[URL]http://www.cambridge.org/us/academic/subjects/physics/electronics-physicists/art-electronics-3rd-edition[/URL][/QUOTE]
I hadn't heard of this book. Mostly because I haven't been looking.
Looks like something I should pick up, electricity hasn't really changed since the first edition publishing in 1980, last time I checked it's still just electrons flowing.
$120 is a bit pricey, but it's a 1000+ page hardcover...
I bet I could find the second edition cheaper somewhere, but the third edition seems to include tons of data about the circuits described in the book. They've got oscilloscope screenshots and all kinds of graphs and tables.
Edit:
My local library has two copies of second edition available.
I haven't been to the library in... wow. A long time. Looks like I need to pay a visit.
I like the red cover on the second edition more tbh.
Oh, how handy.
[url=http://www.americanradiohistory.com/Radio_Electronics%20_Master_Page.htm]Someone has been scanning in all the issues of Radio Electronics since 1948 and releasing them in PDF format.[/url]
[QUOTE=pentium;47025921]Oh, how handy.
[url=http://www.americanradiohistory.com/Radio_Electronics%20_Master_Page.htm]Someone has been scanning in all the issues of Radio Electronics since 1948 and releasing them in PDF format.[/url][/QUOTE]
I fucking love old electronics magazines, even for the older tube based stuff there are good circuits and techniques in there.
[QUOTE=nikomo;47025228]
$120 is a bit pricey, but it's a 1000+ page hardcover...
I bet I could find the second edition cheaper somewhere, but the third edition seems to include tons of data about the circuits described in the book. They've got oscilloscope screenshots and all kinds of graphs and tables.
[/QUOTE]
You can get the 2nd edition (paperback) for like $25 from India since they sell it a lot cheaper there, I can't imagine there being a huge difference in the 3rd edition although it does have about 250 more pages, I suspect that to be mostly digital and microcontrollers.
[img]http://uk.farnell.com/productimages/standard/en_GB/2448156-40.jpg[/img]
There is no way they made it look like that accidentally...
[url]http://www.farnell.com/datasheets/1850451.pdf[/url]
[QUOTE=pentium;47025921]Oh, how handy.
[url=http://www.americanradiohistory.com/Radio_Electronics%20_Master_Page.htm]Someone has been scanning in all the issues of Radio Electronics since 1948 and releasing them in PDF format.[/url][/QUOTE]
If only there was some way to download them in batches, even just one archive file per year would be helpful.
wget the site perhaps?
[QUOTE=Cakebatyr;47028859]If only there was some way to download them in batches, even just one archive file per year would be helpful.[/QUOTE]
Probably easy enough with some curl magic.
[QUOTE=pentium;47029469]wget the site perhaps?[/QUOTE]
or that.
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