Engineering

Well, time for some electronics questions that are so basic you'll think I ride the short-bus to school... Basically, there's a plant I want to grow, and it requires cool water around it's roots. Because I don't have the time to put icecubes on the damn soil all day, I decided that I wanted to find a way too cool it down automaticly. And I found the perfect things: Peltier junctions (apparently also called Thermo-electric coolers), which transform electrical energy into a heat difference across the device, with one side cooling and the other warming up. I can find lots of them, with lots of statistics on them, but here's the problem: Although I took a bit of el…

Hello, I am new here, so hi all again Here goes my question: Why is it unattractive to use a low reaction (having most of the static-pressure rise in the stator) for a single-stage axial-flow cooling fan for electronic equipment? Reasons. Greetings.

Yesterday I saw on the science channel Rutan Space Ship One. Interesting, he is the public private sector. The government will never share there expertise with Rutan. If they do they will control him and his ship. Any thoughts here? pljames

This new invention of the Hidrogen Car seems to be not so good idea. I once tried to do this but i get to realize that the process to get the hidrogen fuel, makes more pollution that the gas or diesel theirselfs, so, whats your opinion?

Could an EMP be used to disable the detonation device of a nuclear missile? Or are simple pressure sensors all that is needed for detonation?

These 2 are the best multirole combat jets i consider of USA and Russia? But... which one is the true best? Or in which specs is one better from the other? I trust in soviet engineering though. I (L) Berkut

I have a technical question about the alternator and the battery charge. When you strart up your vehicle on a low battery, eventually the battery will reach full charge. The charge generated by the alternator recharges the battery. When you have a full battery, however, what happens to the charge that the alternator produces. Is it simply pumped into the fully charged battery or where does it go? Seems like a tremendous inefficiency because performance doesn't seem to be influenced much by battery charge. In all situations, the alternator cranks out charge (irrespective of battery charge and applicance energy draw). Would appreciate it if someone with more experience or m…

Hi, I'm curious whether anyone knows of any software available for the simulation of single electron transistors (SET), or more importantly, circuits composed of SETs. Thanks!

would it be possible to have a giant particle accelerator in orbit around the sun? find a nice, big space(like between some of the farther planets) and have some strategically placed asteroids with powerful magnets orbit the sun. well, could it work?

hey all . At the moment I have a forty dollar gift voucher for a hardware store and my plans are to turn that forty dollars into something more (because Im broke and bored ). I have friends who would buy a case if I could make my ideas come true . I'm intending to build the case from scratch and I just want some advice on a couple things I'm tossing around in my head . Whats the best way of making a mould ? at the moment I'm thinking of just plastering a couple layers of wroughted mesh , any other (easier) alternatives . What kind of polymer is best & cheapest to use in a mould ? Any other advice from people who've attempted this .

I'm taking part in a local water-rocket competition. I was thinking about building a rocker-aeroplane hybrid as the distance rocket. I used a delta wing design(swept-back at 25 degree) with a T-tail. However, my rocket has a tendencency to stall after launch (approx 30m). Further trimming odes not fix this. Does anyone have any ideas? P.S.: I have built a conventional rocket for the distance category in the evnt that this fails or the wind is too strong. (so don't suggest me to build a conventional one: I have already built it) For the duration category, I got problems with the parachute deployment system. the problem is either holding the nose cone stable during …

can any1 get me a website or send me some shematics for a turbojet? andrewweber@xwires.net

I was reading some articles on the "future" of TVIP, that is TV over the internet. Is this stuff for real ? How on earth can a tv signal be broadcast over the internet? I think this is a case of really PURE HYPE! A tv signal needs at least 4MHZ bandwidth so if 1000 people over the internet want to see that station (from anywhere in the world) the tv station server would have to send the digital IP packets at 4GHZ! and what if all of a sudden 10,000 people wanted to see the station? then the TVIP server would have to send the signal at 40GHZ! THAT TO ME SOUNDS LIKE PURE HYPE!!!

ok i seen some 1 selling plans for an ion gun that can pop ballons at a 8' range i love trying electronics projects but this one seems a little far fetched. does any 1 have any experience with this type of application and any links if possible

Hi there!!! With the ongoing rise in perfume prices, I'd really like to know how I can refill an empty perfume bottle (ex. Polo Sport, Acqua Di Gio) without having to break the seal. Can anyone here help me out? Thanks!!! Gio

I don't know much about machines, hydraulics, or engineering, but I want to make something that can shoot badminton birdies at high velocity. I'm not sure how to make it, how the machine would work, what the machine is made of, etc. I'm limited on money so I can't make anything that costs a lot. My first idea was to use pressurized air or something. Would that even work? The birdie is light. Where would the pressurized air come from? How do I build a machine that uses this concept? How would the birdies load? Where do I get my supplies from?

would it be possible to make a real working lightsaber? i think maybe plasma could be manipulated by a magnetic field for the beam. put somthin in if u hav any ideas

Hey guys, I have a Core Engineering exam tomorrow, and theres a few questions from past papers that I'm stumped on. If someone could give me some tips today that would be great. How are rails in railway tracks made? How do the relative costs of initial setup, tooling and materials change with the number of components and manufactures? How does the molecular weight of a polymer affect its properties? How can I draw an FCC crystal and indicate it's Miller incide on the same diagram? Name and sketch the process by which most domestic ceramic products are manufactured Give an example of a simple forged component and sketch the important features of the dies yo…

Hello, Can some people please explain the differences between solar cells and photocells. Is it only, solar cells use photoelectric effect to create current and photocells use the effect to detect light. THank you in advance

I dug a nice big toroidal power supply from a broken 400w RMS speaker set and I'm trying to get it to work to supply low (relatively) voltage and a decent amount of current. It has three leads on one side and two on the opposite. Red/white and yellow/orange/black in case it matters. The resistances I read are as follows: Red - White 2.1 Yellow - Orange 0.9 Black - Orange 0.9 Black - Yellow 0.9 (I don't have any way to measure inductors, so this is a rough guess) Now before I tested this out, I hooked the yellow & orange to 110 VAC wall socket and it, of course, flipped the breaker. How can this be used to step down AC voltage if Ohm's…

I am going to be doing a degree in electrical engineering once i have finished my A-levels (maths/physics). I will have approx 9 months before i start and i would like to learn some theory as i only really do pretty basic stuff in physics with regards to circuits etc. What kind of books should i start out with to get me at a reasonable level of knowledge before i start the course?

hey if i have a simple ac generator (i.e. a coil of wire roating in between two magnets), to get power out of it i need to connect the wire to a thing called a "commutator", is that right? i can't quite figure out exactly how this all works... -Sarah

I would like to make a double-parabolic mirror like the one here for a project. How good of a reflector would gold leaf be? Would it be better, worse, or about the same as aluminum foil? Keep in mind, I'm going for the quality of the reproduced image. Thanks P.S. Any hints on how to get a hold of the exact dimensions of the parabola they use? Thanks.

I saw this thing my math teacher made. At first it looked like a gumball machine with a sphere for the gumballs and a pole that holds it up. The device actually made lightning pop out. When he turned off the light and switched the machine on, lightning shot out of it. He put his arm next to the thing when it was on and it made his muscles twitch. He says the muscles responded or something to it because they are electrical. It made a classmate's hair stand up on end. The class made held arms and the shock went through everyone. It made my feet feel weird. It crackled when it hit someone. It felt like someone pinched you. If you used a microscope, you can see burns because …

not dutch force.. i've got that one.. not electronic's lab either.. i've got that one... i'm looking for other forums that are just as good as those..