Engineering

I am interfacing a pic microcontroller with an electronic compass module via spi interface. The problem is the pic outputs at 5v and the compass will only handle 3v. I am thinking voltage divider for any inputs to the compass and an opamp for outputs. What is the best way to drop and increase voltage in digital circuits?

Hey guys Need some help, I have a PCB built and it doesn't quite operate as I expect it to. I have a PIC microcontroller and a couple of LEDs which should be on when it is operating. The ground and power planes are providing power to the PIC, the MCLR pin is set high and the rest of hte circuit seems to work. However, the PIC just doesn't work. It seems to burn out after awhile. Another phenomena which happened was the LEDs turned on when I brought my hand over the board, but turned off when I pulled it away. The circuit died soon after. And funnily enough, the PIC seems to be fine. I just reprogram it and put it back in, and it operates (until it die…

OK, I have an idea which is much like a Creative Zen Portable Media center. How would I go about designing something like that. I have a B.A. in EE, but approaching a project of that complexity is another matter. For that matter, I don't even know everything I would need in designing that system. Is there a computer aided system I could use? Or what about micro boards and such. Help please! Any books I could read? I have access to an extensive library.

hey! im in the middle of creating a electrostatic motor for my grade 8 science fair project. here---> http://amasci.com/emotor/emot1.html im using the pvc pipe methode to run my motor here----->http://home.earthlink.net/~lenyr/stat-gen.htm . i wanted to incorprate the Film Can Capacitor into the project also. so i got to thinking, would it be possible to run the generator,to the capactior to the motor? where by i connect the wire to the screw on the top of the film can then on to the eletric motor,would this work? OR shold i just directly connect the pvc pipe to the motor.... THANKS (im sorry in advance for posting in wrong forum i wasent sure...…

What would happen if electrons have more or less charge than it is now?

I'm thinking about GPS, and the problems with the technoledgy. What are the technical ways of finding your current position on the earth? Any idea welcome even imposible ones, I was wondering if the sun could be used. Maybe combine the suns direction with the precise time, but how acurate? but I suspect it's a little too imposible technicaly. thoughts welcome. P.S how do you spell check on these forums?

I've got an idea about jet propulsion from ionic propulsion, which doesn't require chemical fuels. Only electricity and some metal plates. (this idea comes from the ionic breeze) I know that some people are trying to do this and I want to do it too. basically it works like this: 1.air is ionized 2.air is accelerated through the metal plates(which are electrically charged) 3.air exits the engine and propells the engine forward. the only problems that i have seen with this type of propulsion is that it doesnt produce much thrust. only about 2lbs thrust with and engine that has about 1.5 square meters of surface area for the air to become ionized and push on the engi…

A hybrid rocket engine is one that uses a combonation of liquid oxidizer and solid fuel grain. A hybrid engine was recently used on Space Ship One to win the Ansari X Prize. This engine used N2O (Nitrous Oxide) injected into a combustion chamber full of Hydroxy-terminated polybutadiene (HTPB), a synthetic rubber commonly used in tires. But I have never heard of a hybrid motor that uses liquid fuel with a solid oxidizer. What if you compressed an oxidizing agent into a dense grain and injected liquid fuel such as alcohol into the chamber containing the solid oxidizer such as NH4NO3, NH4ClO4, KNO3, or KClO4 which are all common in rocket propellents. Are liquid oxidizer…

i am trying to make a pulse detonation engine.... i got the basic framework down; the tubing for the gases, and the metal piping for the combustion chamber and the cooling system, i got a butane tank too, i just need a few things... 1. an oscillating circuit for the spark plug. 2. an air pump to pump air into the chamber.

Since we light buildings with 60 cycle flourescent lights, we are actually being strobed 60 times a second and in the dark 60 times a second. I have a doorway 8ft high by 3ft wide and I rig it so a 2" metal bar drops from ceiling to floor spanning the doorway on a chain drive in the walls. Then the bar returns up behind as another drops in front connected to the same chain. With 24ft of chain in the loop and about a 1000 rpm motor and gearing I could have the bars drop from ceiling to floor in less than 120th of a second. I could time it so the bar only dropped in between strobes. Wouldn't an observer see an empty doorway but experience an invisible wall of steel? …

I watched 60 Minutes on Sunday and they showed a factory building 2000lb dumb bombs. What I was curious about was why did they fill them with concrete? I saw them pour concrete in the 9 foot hollow shells stood up on end. What is the physics or common sense logic behind this? Why not BBs or scrap metal? Just aman

I figured this was more appropriate than the Computer science forum, since this is more of an electronics question. I've noticed that many computer power supplies have a label on them, listing things like "+12V, 15A" and "-12V, 0.3A" and suchlike. I know the V and A mean volts and amps, but I'm a bit unclear of the meaning of the + and - signs with respect to voltages. Isn't voltage always a difference in potential, thus doesn't get a sign like that? Basically, I want to hook something up to the power supply with a 2 Ohm resistance, and I want to know what wires to connect it to. Mokele, probably well out of his depth on this project.

If you sow the movie with the super gun for Iraq you will know what I suggest : Big gun that will fire small craft’s in the orbit in the shell , at some altitude shell will break and craft will start his own engines What are you think it will cost more or less for launch of the craft Jules Vern

hi, iam having my 7th semester of b-tech in ECE. this 29 infosys is coming for recruitment. so pls sent me with good tips and some important qns pls... also sent me any materials for wireless commn and cryptography .. pls ........................pls................ -----Venki

I found a "Dynex RF Modulator AV Signal Converter WS-007" in my house. It's about 2 years old and since it's no longer under warranty support won't offer any help. When I plug it in the red light on the front lights up for a split second then fades out jut as quick. It doesn't matter whether my rca cables are plugged in or not. When the red light comes on, the video signal from my camera shows up on the TV, but then disappears as soon the light fades away. I was thinking of opening it up, but I'm not sure what to look for. Any ideas?

If you've ever seen the movie "the hunt for red october" (tom clancy novel), it says how a submarine has a silent propulsion system. they explain it as a jet engine for water, but with no moving parts. i was just curious if this is even possible, and if it is, how it would work. I've been looking at the site, and i like it, im only a jr. in high school, so i don't understand too much of the real technical stuff yet. but i think im leaning toward engineering for a career and all. another quick question, how do nuclear reactors transmit energy from nuclear to mechanical? is it steam...can't remember for some reason right now. wonder if zarkov has any cr…

is there anyway to make a bomb that wen explodes it freezes everything in the blast radius?

i was surfing the net yesterday and found somthing about these engines that they use less fuel and give out more power i wanted to look at a diagram of the PDE but never found one and would like to find out more about ho these work since i am unfamiliar with them

I just thaught about a camera which is spherical and can catch up all things in its sorrounding, lly as we take a look standing a place. Then this camera sends information to a device i call it Arti-enviro. It means artifecial environment which is also a spherical LCD display, viewable from its inner surface (we have to enter a spherical room) This room shows us the same environment as catch up by the camera. The query is that is such type of thing alreadily done, on search, or impossible........What do U think

Is it at all likely that we'll eventually be able to build things on scales smaller than nanoscale? What problems would we encounter when building things out of nucleons, or even quarks? If the quark has a substructure, could we go beyond? Is it at all feasible that we'd eventually be able to build even on the planck scale?

I don't know if at one time NASA studied the feasibility of growing plants in space for oxygen and food, and I don't know if this idea has been overlooked or not: It is much less feasible to use any kind of fluorescent or halogen lamps in space, because of weight, power requirements, fragility, poor lifespan, and bulk. LEDs are becoming just about as power efficient, and they generate little heat, are much less bulky for the light they produce, weigh a lot less, and are very much simpler to install. They can be handwired if they have leads, soldered to circuit board material in easy to build arrays, are extremely sturdy compared to light bulbs and fluorescent tubes,…

http://en.wikipedia.org/wiki/Nuclear_thermal_rocket any thoughts?

What is up? Me and a friend of mine are going to be attempting to turn his car into a hydrogen fueled car. The way we see it, it would actually help the ecosystem because it would be releasing much needed oxygen into the atmosphere instead of CO2 (I think?). If we succeed we will be entering it in for scholarships and the like. We are both going into a field of some kind of Physics. I know he wants Theoretical, I dunno what I am doing though. Anyway, does anyone have any suggestions on some ways to do this? Has anyone had any experience in trying to make one and have any tips? Thanks for any help. EDIT: First, we will be working with lawn …

anyone could tell me how it is and how it work (a transiente noise simulator)? (no too much specific) what is a incidence matrix in a network? (i only need to know the "technical" definitions)

Heres a problem I've tried doing for ages but I can't quite get it right The answer is *apparently* approximately 10.8 degrees. Heres the question and a diagram to help visualise: Three smooth cylinders are stacked up in a trough as shown in the diagram below. Each cylinder weighs 400N and has a diameter of 125mm. Calculate the minimum angle theta which will support these cylinders in equilibrium.