~
Oxford PV was spun from the University of Oxford to develop solar cell window.
From the Clarendon Laboratory, its basic technology, a screen-printable Solid-state dye-sensitized solar cell (DSSC) is.
(
Read more
)
- +1
- 18 February 2011, 17:12
- admin
They said it could be done and now they've done it. What's more, they did it with a GRIN. A team of scientists with the U.S. Department of Energy (DOE)'s Lawrence Berkeley National Laboratory (Berkeley Lab) and the University of California, Berkeley, have carried out the first experimental demonstration of GRIN — for gradient index — plasmonics, a hybrid technology that opens the door to a wide range of exotic optics, including superfast computers based on light rather than electronic signals, ultra-powerful optical microscopes able to resolve DNA molecules with visible light, and «invisibility» carpet-cloaking devices.
(
Read more
)
- +1
- 17 February 2011, 17:01
- Soarer
Tablet devices are bursting back onto the scene and stand to be on the most-wanted gadget list for many geeks in the near future. Rallied by the success of Apple’s iPad, manufacturers are charging back into the tablet form factor, offering both familiar and innovative ways for us to interact with our machines. In this TechTip, we’re talkin’ tablets!
(
Read more
)
- +1
- 17 February 2011, 16:50
- Soarer
The Russian inventor of the «National Bureau of Radioengineering» found a new simple and cheap way to transfer information over long distances (100-150 km) — namely, on the networks of pipelines of various purpose (gas, oil and water pipes).
(
Read more
)
The explanation of the photoelectric effect, based on the replacement of a photon of energy ħω sequence ω solitons
Introduction. In 1905, Albert Einstein, Max Planck developed the ideas, gave the first theoretical explanation of the experimental dependences of the photoelectric effect, for which he later received the Nobel Prize [1]. These relationships are shown in Figure 1 (a, b) [2].
(
Read more
)
The National Administration of the U.S. Telecommunications and Information Administration (NTIA) in exceptionally extended ICANN's 6-month duration of the contract to manage the Internet (IANA — Internet Address Space Administration), the message says NTIA.
(
Read more
)
The experts «Kaspersky Lab» conducted an analysis of viral activity in February 2012. According to the company, mobile threats have reached a qualitatively new level.
(
Read more
)
The company «Doctor Web» reports on the identification of a new distribution scheme of threats to personal computers and devices running the operating system Mac OS X.
(
Read more
)
Internet portal RapidShare says not to worry for their future in the light of the recent unprecedented raid on its main competitor MegaUpload, although it also has a database as clients, exchanging legal content, and more. In RapidShare say they are ready in case of unforeseen situations, to provide protection at least for legal clients. Today, the Internet RapidShare is the second largest repository of digital content files after MegaUpload.
(
Read more
)
So far, we have discussed the basic electronic components, and power supply circuits. We have touched on filters, but not discussed them in detail. No course on electronics would be complete without a thorough understanding of filters, how they work, and how to recognize them when you see them.
(
Read more
)
- 0
- 21 February 2012, 01:07
- Valery
Before going into the specifics of how a Klystron tube works, we must first understand it’s basic parts. Which reminds me of a story….
(
Read more
)
- 0
- 21 February 2012, 00:40
- Valery
Thomas Edison, famous (at least in America), for inventing the light bulb, made many discoveries before he completed his task of lighting the path of the world. Along the way, he incidentally noted that if a filament were energised within a vacuum, that after time, a “shadow” would be left on the inside of the glass, which resembled the shape of the filament.
(
Read more
)
- 0
- 21 February 2012, 00:29
- Valery
Now that we have caught up on basic tube theory, and understand how a beam of electrons can be formed in a vacuum, we are well on our way to understanding how a KLYSTRON operates.
(
Read more
)
- 0
- 21 February 2012, 00:01
- Valery
Sounds like a great title for a science fiction novel, doesn’t it? Well, perhaps another time. But now we are going to discuss some of the intricacies and dangers of klystrons.
(
Read more
)
- 0
- 20 February 2012, 23:56
- Valery
Another important factor when dealing with klystrons is heat. Not all of the developed in the cathode becomes radiated output. Much of the energy is dissipated as heat. If the tube gets too hot, it can become a hazard to itself. Temperature sensors are placed in various places to shut down the tube in the event of overheating.
(
Read more
)
- 0
- 20 February 2012, 23:51
- Valery
In the last section, we saw how a very simple transmitter worked. It was made up of several different types of electronic components, including capacitors, transistors, resistors, etc. When we assemble several types of electronic components in a configuration that serves some purpose, we call it a CIRCUIT.
(
Read more
)
- 0
- 20 February 2012, 23:45
- Valery
Knowing what a diode is, or how a triode works is of little use unless you have some practical knowledge of how it can be applied within a circuit. We are going to begin with a VERY basic schematic of an early transmitter. Do NOT try to build this at home!
(
Read more
)
- 0
- 20 February 2012, 23:40
- Valery
Up to now, you have learned something about the diode vacuum tube and how it works. The most important point to rember about the diode is that it only allows current to flow IN ONE DIRECTION.
(
Read more
)
- 0
- 20 February 2012, 23:36
- Valery
As discussed in the previous lesson, a Characteristic Curve is found by applying several different voltage levels, and measuring plate voltages vs. plate current. We note that in a diode, if we go below a certain plate voltage, ( in this case 0 volts ) no plate current flows. The minimum point at which the tube no longer operates is called the CUTOFF POINT.
(
Read more
)
- 0
- 20 February 2012, 23:29
- Valery
Both of the schematics above show the operation of a diode tube. Now let’s study a little about the theory of it’s use.
(
Read more
)
- 0
- 20 February 2012, 22:10
- Valery
|
|
