Electronic Keypad Lock (120V ON/OFF)?

I’m looking for an electronic lock w/ keypad. I’m looking for something to open/close and electronic circuit (like to turn on/off a light bulb). I’ve searched all over the internet, only finding electronic DOOR locks (I don’t want to use these). I was hoping to find one that has 12 keys (0-9, #, Ӿ), an LED/LCD display (to show keys hit, open/close, or anything else), and 3 LED’s (they would be to indicate ELECTRICITY FLOWING, CORRECT, INCORRECT). Anyone know where I could find something like this? Thanks!

How could i design an electronic circuit to automatically switch on & switch off the generator ?

I want to use generator for home usage. I want to make an electrical panel that consist of an electronic circuit which switch on the generator when the electricity (provided by the company) is failed and switch it off when electricity (provided by electric supply corporation) starting to flow.

how can i do that ? what would be the cost ? what things should we need to achieve that task ?

thanks

class essay dont delete?

David Solórzano
Ceramic Engineering
Field Report

Ceramic Engineering is the technology of making and using of ceramic materials. Many engineering applications benefit from ceramic materials. Ceramic materials have gained attention from engineers around the world, including: Electrical Engineering, Materials Engineering, Chemical Engineering, Mechanical Engineering, and many others. Ceramics are resistant to heat, and can be used for many tasks that other materials like metal and polymers can’t.

Ceramic materials may have a crystalline or partly crystalline structure, with long-range order on a molecular scale. Glass ceramics may have an amorphous or glassy structure, with limited or short-range molecular order. They are either formed from a molten mass that solidifies on cooling, formed and matured by the action of heat, or chemically synthesized at low temperatures using the solution/precipitation technique known commonly as Sol-gel.

The special character of ceramic materials gives rise to many engineering applications and ceramics have attracted the attention of engineers in electrical engineering, materials engineering, chemical engineering and mechanical engineering. As ceramics are heat resistant, they can be used for many tasks that materials like metal and polymers are unsuitable for. Ceramic materials are used in a wide range of industries, including mining, aerospace, medicine, refinery, the food industry, the chemical industry, packaging science, electronics, industrial and transmission electricity, and guided light wave transmission.

Introduction
Ceramic Engineering is the technology of manufacturing and usage of ceramic materials. Many engineering applications benefit from ceramics characteristics as a material. The characteristics of ceramics have garnered attention from engineers across the world, including those in the fields: Electrical Engineering, Materials Engineering, Chemical Engineering, Mechanical Engineering, and many others. Highly regarded for being resistant to heat, ceramics can be used for many demanding tasks that other materials like Metal and Polymers can’t. Ceramics, in addition to being a fine art, also requires a thorough working knowledge of certain materials. Whether we need to design a new office building, or a vase for our bedroom, we need a ceramic engineer. Someone has to figure out our creative designs into a reality and here walks in the engineer. A ceramicist joins ceramics and engineering and helps us to create new and more interesting works with new materials, which we can’t, even dream of. The multibillion-dollar ceramic industry converts processed materials and raw materials taken directly from the earth (clay, sand, etc.) into such useful products as spark plugs, glass, electronic components, nuclear materials, abrasives, rocket components, and even tableware. High-temperature processing is the key to ceramic engineering, and the products are always inorganic, nonmetallic solids.

Job Prospects
Ceramic Engineers experienced in both scientific and production aspects of the profession may also work as administrators, project supervisors, sales engineers or technical consultants to firms using ceramic materials. Many Ceramic Engineers work in the nuclear field, as ceramic fuel materials make nuclear power generation possible. The electronics industry is a growth area for this technology, as ceramics are used as insulators for transistors and integrated circuits. Refractory ceramics are required in the refining of iron and aluminum, and this industry is especially in need of this type of worker. The exciting new field of fiber optics has had a dramatic effect on today’s telecommunication and medical industries, and since ceramic components are used, Ceramic Engineers are playing a vital role in this new science. Ceramic Engineers experienced in both scientific and production aspects of the profession may also work as administrators, project supervisors, sales engineers or technical consultants to firms using ceramic materials.

Nature of Work
CERAMIC ENGINEERS help to develop varied products as protective tiles for space shuttles, ceramic fillings for teeth, Unbreakable dinner plates, and sophisticated telescope lenses. Ceramics have applications in virtually any industry, which demands the use of heat-resistant materials. Ceramic Engineers are specialists in the study of these materials, their behavior, application, and use. They develop methods for processing nonmetallic inorganic materials into many ceramic products ranging from glassware, fiber optics products, cement, and bricks, to coatings for space vehicles, materials for microelectronics, components of nuclear fuel, and pollution control devices. Recent advances in physics and chemistry have expanded the applications of ceramic engineering. The major functions of Ceramic Engineers are Research, product development, and production engineering. The e

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?

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?

How could electric eel makes an electric shock?

How is that possible? I read in wikipedia and they say it's about 650 volts! And that means fishes are a step ahead us because they have known and controlled electricity much longer than human being! (haha)

By the way, back to the topic. I just don't understand how it works, because they swim on water but they don't get a "short circuit" (you know what I mean, imagine if you soak electronic devices on water) and they can "turn" the electricity on everytime they want.

Another stupid question, if 1 electric eel could make 650 volts, could we use that energy? Like take a lot of electric eels and put them together in a bucket and then make them angry so they make electricity and we use that energy?

Stupid question number 2, what happens if we juice 'em with electricity? Are they gonna die?

Sorry for the stupid questions, I'm just curious, thanks!

N.B. : I would really appreciate it if someone could explain it in simple english and without scientifical term because I'm not a scientist and I easily could get lost in a hard explanation.

Thanks again!

What is a good book to learn circuitry?

As the title explains I would like to learn basically what a sophomore/junior level EE student would learn. I’m looking for the practical side of circuitry, and less towards the theory. Obviously you need theory to understand practical and vice vursa, but I would like to actually be able to make basic circuits not just understand how they work. I’m a sophomore chemical engineering student and I’ve taken Physics Electricity and magnetics so I understand ac, dc, R,C, L Circuits. Also, is there any book or site that has different chips and what they do etc?

The last thing is I want the book to be cheap…

These are 2 I’ve found through amazon that people seemed to like. Anyone used these?
Teach Yourself Electricity and Electronics, Fourth Edition (Teach Yourself) – Stan Gibilisco; Paperback
A Practical Introduction to Electronic Circuits – Martin Hartley Jones; Paperback

I have a electronic circuit that needs to be on, all time, but in my shop everyday occurs an electricity breakouts, (not more than 2 seconds) but enough to turn off the circuit and it's very hard to re start. My question is: if I can't modify my circuit (just add) How can I install some capacitors (my circuit is 480, 5 Amps, 3 fases), to support the circuit while the breakout occurs? I don't want to add a UPS coz it's so expensive. Thanks