I want to make sure that this 60/40 clear flux solder from radioshack (.063") won’t damage my tv. I need to replace a capacitor on my 37" lcd magnavox. Would rosin core be better?

Please help with one of my physics homework problems I am very stuck on.

"One of the main factors driving improvements in the cost and complexity of integrated circuits (ICs) is improvements in photolithography and the resulting ability to print ever smaller features. Modern circuits are made using a variety of complicated lithography techniques, with the goal to make electronic traces as small and as close to each other as possible (to reduce the overall size, and thus increase the speed). In the end though, all optical techniques are limited by diffraction.
Assume we have a scannable laser that draws a line on a circuit board (the light exposes a line of photoresist, which then becomes impervious to a subsequent chemical etch, leaving only the narrow metal line under the exposed photoresist). Assume the laser wavelength is 248 nm (Krypton Fluoride excimer laser), the initial beam diameter is 1 cm, and the focusing lens (diameter = 1.3 cm) is extremely ‘fast’, with a focal length of only 0.625 cm."

a) What is the approximate width w of the line (defined here as the distance between diffraction minima on either side of the central spot/ridge — see figure)?

b) What is the minimum resolvable line separation between adjacent lines?

c) If the laser wavelength is instead reduced to 157 nm (as is now potentially available with Argon Fluoride excimer lasers, though technical challenges remain), what is the new minimum resolvable line separation?

d) Assuming the size of the traces is the only constraint limiting the ‘areal density’ (i.e., how many components can be laid out per square centimeter), by what factor does the areal density increase in going from a writing laser with λ = 248 nm to one with λ = 157 nm?

e) Going back to the lithography system with a laser that produces light (in air) at λ = 248 nm, what minimum line separation can be expected in this case (i.e., what is the new answer to b), if the space between the lens and the photoresist is filled with water [n = 1.33 for water])? Hint: What effect does the index have on the wavelength of the light?

I have just started with bread board electronic circuit, which is nails on a wood board connected by wires and Components. I have made a flasher which is just 2 flashing LE-D’s, But is there a free program to Design and test a virtual circuit board? were you physicaly place components andConnectt them to see the results? I do have a physics program at school that does it sort what im talking bout its called crocodilee physicss" is there a free circuit board designin softwar spicilyly made for electronics, were you make and test you creationsn virtually lbeforeo actually making them in real life?

What is the full name of an Element starting with Q?
On a circuit board there are labels. For example for resistors it is "R", for diode "D", for capacitor "C" what is "Q" for?

I’m learning programming for the first time (starting with C for beginner) but I first I want to understand exactly what happens when I type the key, let’s say "b" on my keyboard and seeing letter "b" appear on a notepad for instance.

My guess is this and I’m not sure to what extent it is correct:

First, a computer is, physically speaking, nothing but electricity and circuitry (matter; electronic components such as resistors, capacitors etc and electrical power which comes from the battery/wall and finally the way all these are connected to one another)

1. The keyboard, being an electronic device, needs electricity in order to work so it is powered by the computer through the USB port.

2. By pressing any key ("be" in our case), I’m actually closing a circuit which makes some current/voltage flow (high for 1 and low for 0)

3. Some programs (Operating system which then communicates to notepad God knows how) convert this series of high’s and low’s or 0’s and 1’s into what I see on my screen as letter "b" on the notepad.

Am I close to the reality of computing?

I mean how does the computer know that I have actually pressed the key "b" on the keyboard and not "a", does every key send some sort of special current or something? This part I need clarifying the most!

Does this have anything to do with "Hex"?

Thank you.
where does the processor come into play in all of this? my processor is 2 GHz, what does this mean in terms of typing and seeing something on the screen?

I have been interested in building electronic circuits for a long time, but the diagrams would baffle me. i understand a bunch now but i see the ground wire symbol and wonder "what do i do with that?". so if im building a circuit that connects to the battery where do i connect the ground to? the negative end? the actual ground? idk please help!

Hello, all –

I am looking to build a simple sound activated switch for my Canon XT DSLR camera. The camera has a jack (3/32" stereo) that is wired in this way –http://farm1.static.flickr.com/146/359549791_83d835b78a.jpg

Hooking up a simple wire to the jack via a plug and closing the circuit will fire the shutter, so the jack has a current running across it. The current its, I think, 3.5V at .5A (i’ll try to confirm that, the lack of a multimeter is yet again haunting me).

I have a decent competency in reading circuit diagrams /soldering. All this has to do is close a circuit once there is a loud sound (Not fire a flash, etc).

My biggest qualm is hooking something with voltage up to a live jack — guides how to modify one of the following circuits would be best, or a separate diagram/description would work too.

http://www.electronic-circuits-diagrams.com/audioimages/9.gif

http://www.hiviz.com/tools/triggers/SNDTRIG.GIF (more me-friendly).

Thanks for your help!
something along these lines: http://www.radioshack.com/product/index.jsp?productId=2062479?

In the circuit given here: http://www.elektronika.ba/el.sheme/fajlovi/r86.gif
"when all keys have been pressed in correct order Q7 goes high for about four seconds to drive the "unlock" circuitry (a relay driver for an automatic door opener).
Can anyone tell me how can i connect that relay driver? And how to connect LEDs (green if the keys are pressed in correct order, and Red if they are not).
Please help me to solve this problem.
Thanks!!!!!

Hypothetically.. if you wanted to make a giant circuit board to handlee all the wiring in a car would it be possible? I mean a printed circuit board like a PC motherboard.. NOT somekind of board with wires running on it.. what are they called.. :bread boards" or something..?
Beau, why do they use printed circuit boards in computers rather than wires? That's the same reason I am wondering why they don't use printed circuits for car wiring…

And, I am just curiou how the concept of printed circuits scales up.. would it be feasible for wriing a car? Or would you it not have enough material to run enough electricity through it to make it work..
I know it would be tough to do this inside the engine bay.. but how about all the wiriing from the firewall back.. and don't think of just one board..

Or how about wiring in your house.. hypothetically.. would the concept of the circuit board work for home wiring? How would this work? How wide would a "band" of curcuit need to be to handle home wiring? What's the largest example of a circuit board?

Model 790.95301, had this range for 5 years, never had any problems with it. Cooked dinner this evening and shut it off when we were thru. About 5 minutes go by and the buzzer starts going off and there is an "F1" fault code on the display.
The bottom element in the oven is red hot, like during the self cleaning mode. We tried resetting the oven, even unplugged it for awhile but keep getting the fault code. Every time we plug it back in the element gets red hot again. Can anyone tell me what the "F1" code is for? I assume it is electronic, maybe a circuit board gone bad? Any help is appreciated.