RC Integrator

For a passive RC integrator circuit, the input is connected to a resistance while the output voltage is taken from across a capacitor being the exact opposite to the RC Differentiator Circuit. The capacitor charges up when the input is high and discharges when the input is low.

In Electronics, the basic series connected resistor-capacitor (RC) circuit has many uses and applications from basic charging/discharging circuits to high-order filter circuits. This two component passive RC circuit may look simple enough, but depending on the type and frequency of the applied input signal, the behaviour and response of this basic RC circuit can be very different.

Thus the rate of charging or discharging depends on the RC time constant, τ = RC. Consider the circuit below.

RC Integrator

 

For an RC integrator circuit, the input signal is applied to the resistance with the output taken across the capacitor, then VOUT equals VC. As the capacitor is a frequency dependant element, the amount of charge that is established across the plates is equal to the time domain integral of the current. That is it takes a certain amount of time for the capacitor to fully charge as the capacitor can not charge instantaneously only charge exponentially.

Therefore the capacitor current can be written as:

 

This basic equation above of iC = C(dVc/dt) can also be expressed as the instantaneous rate of change of charge, Q with respect to time giving us the following standard equation of: iC = dQ/dt where the charge Q = C x Vc, that is capacitance times voltage.

The rate at which the capacitor charges (or discharges) is directly proportional to the amount of the resistance and capacitance giving the time constant of the circuit. Thus the time constant of a RC integrator circuit is the time interval that equals the product of R and C.

Since capacitance is equal to Q/Vc where electrical charge, Q is the flow of a current (i) over time (t), that is the product of i x t in coulombs, and from Ohms law we know that voltage (V) is equal to i x R, substituting these into the equation for the RC time constant gives:

RC Time Constant

Astable Multivibrator

Regenerative switching circuits such as Astable Multivibrators are the most commonly used type of relaxation oscillator because not only are they simple, reliable and ease of construction they also produce a constant square wave output waveform.

Unlike the Monostable Multivibrator or the Bistable Multivibrator we looked at in the previous tutorials that require an “external” trigger pulse for their operation, the Astable Multivibrator has automatic built in triggering which switches it continuously between its two unstable states both set and reset.

https://www.electronics-tutorials.ws/waveforms/astable.html

The Astable Multivibrator is another type of cross-coupled transistor switching circuit that has NO stable output states as it changes from one state to the other all the time. The astable circuit consists of two switching transistors, a cross-coupled feedback network, and two time delay capacitors which allows oscillation between the two states with no external triggering to produce the change in state.

In electronic circuits, astable multivibrators are also known as Free-running Multivibrator as they do not require any additional inputs or external assistance to oscillate. Astable oscillators produce a continuous square wave from its output or outputs, (two outputs no inputs) which can then be used to flash lights or produce a sound in a loudspeaker.

The basic transistor circuit for an Astable Multivibrator produces a square wave output from a pair of grounded emitter cross-coupled transistors. Both transistors either NPN or PNP, in the multivibrator are biased for linear operation and are operated as Common Emitter Amplifiers with 100% positive feedback.

This configuration satisfies the condition for oscillation when: ( βA = 1∠ 0o ). This results in one stage conducting “fully-ON” (Saturation) while the other is switched “fully-OFF” (cut-off) giving a very high level of mutual amplification between the two transistors. Conduction is transferred from one stage to the other by the discharging action of a capacitor through a resistor as shown below.

Astable Multivibrators Periodic Time

TRANSISTOR AS A SWITCH

When used as an AC signal amplifier, the transistors Base biasing voltage is applied in such a way that it always operates within its “active” region, that is the linear part of the output characteristics curves are used.

However, both the NPN & PNP type bipolar transistors can be made to operate as “ON/OFF” type solid state switch by biasing the transistors Base terminal differently to that for a signal amplifier.

Solid state switches are one of the main applications for the use of transistor to switch a DC output “ON” or “OFF”. Some output devices, such as LED’s only require a few milli amps at logic level DC voltages and can therefore be driven directly by the output of a logic gate. However, high power devices such as motors, solenoids or lamps, often require more power than that supplied by an ordinary logic gate so transistor switches are used.

If the circuit uses the Bipolar Transistor as a Switch, then the biasing of the transistor, either NPN or PNP is arranged to operate the transistor at both sides of the “ I-V ” characteristics curves we have seen previously.

Google's Kurzweil on teaching human language to computers

Famous inventor and futurist Ray Kurzweil joined Google last month to work on "some of the most difficult problems in computer science," the specific machine learning and language processing.
"The project we intend to do is focus on the natural language understanding," Kurzweil said in an interview Hub singularity (see video below). "We want to give computers the ability to understand the language in which they read."
As Director of Web giant engineering, Kurzweil said that the challenge is not only one of the most difficult but also the most important.
"It's ambitious, in fact there is no project more important than understanding and intelligence re-creation," he said Kurzweil explains that one of the main challenges he and his team on the face Google is that language is hierarchical and only mammals have the ability to understand the hierarchical ideas. Kurzweil notes that computers such as IBM Watson are now programmed to process information in a similar way human.
Kurzweil predicts that the fruits of his research will eventually be applied to the "scale of Google" - Web giants vast data resources.
"I see a few years from now that the majority of search queries will be answered unless you ask," Kurzweil said. "He'll just know it's something you want to see."

The greatest information from CES so far

LAS VEGAS - Press Day at CES saw 12 good hours of press conferences manufacturers of consumer electronics from all backgrounds. Here is the news that mattered most.

TV

TV technology is still one of the most exciting fields at CES, and so far this year is no different. TV and hot technology today is 4K, also known as Ultra HD. Forte has unveiled two HD screens Ultra, 60 inch Purios due this summer and Ultra HD Aquos TV due in the second half of the year. Panasonic has introduced its new range of Smart TVs, including features such as My home screen, allowing everyone in a house to his own home screen personal and Share Swipe 2.0 which allows share content by tapping NFC smartphone people against television, and voice interaction / orientation, through which people can operate a TV remote control commands by speaking Panasonic or smartphone. Samsung reproduces the S9 series, including a 85-inch TV Ultra HD comes with its own floor stand easel comparable.
  One of the most anticipated announcements of the day was actually old news. LG has finally disclosed base price and availability details for its OLED TV, which was one of the stars of the show last year. The 55-inch model will cost about $ 12,000, according to LG American Marketing James Fishler. A 84-inch model will cost more than $ 20,000.
New appliancesLenovo Yoga convertible took its popular and has declined to 11 inches. He also introduced the ThinkPad Helix (below) during the evening event CES Unveiled Sunday. The company calls it a clamshell "rip and flip" design, because the screen is off the base of the keyboard, and can be replaced, even after a rotation of 180 degrees.

chips

During his press conference Sunday evening night, Nvidia launched its Tegra quad-core processor 4, which has greatly improved processing speeds and tricks new camera.

Intel has unveiled its next generation of processors, code-named Haswell, which should allow greater autonomy and new features in mobile devices.

Qualcomm also took a turn on stage, as CEO Paul Jacobs delivered the opening speech of the evening show Monday. Jacobs presented the Snapdragon processors 600 and 800 series, both of which work with the standard 802.11ac wireless and are made for premium mobile computing devices. The high-end 800 series include the newest technology Qualcomm 4G LTE provides data speeds up to 150 Mbps, almost five times faster than previous generation processors.

Games and Entertainment

Nvidia has drawn our attention to start with a prototype of his own portable gaming device brand, codenamed Project Shield. Android-based shield like a console controller greater than usual, with joysticks and buttons. He can play Android, Tegra, and PC games, play games streaming and the cloud. Although the demo was plagued with problems, Nvidia showed how the device can be used for gaming streams from any PC in your home to a big screen TV with what appeared to be gameplay in real time.

java history

java history

The Java was invented by "James Gosling, Patrick Naughton, Ed Frank, Chris Warth, and Mike Sheridan at Sun  Microsystem" , in 1991. Java took 18 months to develop the first working version. This language was starting called "Oak" but was renamed "Java" in 1995. Between the initial development of Oak in the fall of 1992 and the public statement of the language. "Bill Joy, Arthur van Hoff, Jonathan Payne, Frank Yellin, and Tim Lindholm" were key contributors to the maturing of the genuine prototype.

         Somewhat amazingly, the genuine impetus for Java was not the Internet! Instead, the primary inspiration was the need for a platform-independent (that is, architecture-neutral) language that could be used to create software to be embedded on various consumer electronic devices, such as microwave ovens and remote control As you can likely guess, many different kinds of CPUs are used as controllers. The trouble with languages 'C' and 'C++' (and most other languages ) is that they are constructed for that CPU. The trouble is that compilers are expensive and time-consuming to develop.  A simpler- and more cost-efficient- solution was needed. In an attempt to find such a solution, Gosling and others began work on a portable, platform-independent language that could be used to produce code that would run on a different of CPUs under differing  environments. This attempt eventually  led to the creation of Java.
        About the time that the information of Java were being worked out, a second, and eventually more important, factor was emerging that would play a important role in the future of Java. This second force was, of course, the World Wide Web. Had the Web not taken shape at about the same time that Java was being developed, Java might have  remained a useful but unknown language for programming consumer electronics. However, with the emergence of the World Wide Web, Java was propelled to the forefront of computer language layout, because the Web, too, desired convenient programs.
        Most program designers learn early in their careers that convenient programs are as  evasive as they are desirable. While the quest for a way to develop efficient, portable (platform-independent) programs is nearly as old as the discipline of programming itself, it had taken a back seat to other, more pressing troubles. Further, because much of the computer world had separated itself into the three competing camps of Intel, Macintosh, and UNIX, most programmers stayed within their fortified restrictions, and the urgent need for portable code was reduced. However, with the arrival of the Internet and the Web, the old trouble of portability returned with a vengeance. After all, the Internet consists of a diverse, spread over universe populated with many types of computers, operating systems, and CPUs. Even though many kinds of platforms are attached to the Internet, users would like them all to be able to run the same program. What was once an irritating but low-priority troubles had become a high-profile necessity.

What would a US Apple industry mean for American jobs?

When Apple CEO declared last week that the Apple industry will manufacture a collection of Mac computers in the U.S., Tech news Daily considered what that meant for American employees. how many U.S jobs would apple industry create? and what kind of education and expertise would someone need to get one of these hot, new jobs?

Depend on the $100 million that Apple will spend in U.S manufacturing as Cook told Bloomberg Businessweek the Cupertino-depend industry is likely looking to make a number of industry jobs in the "low hundreds," said Pat McGibbon, vice president of technique and research at the connection of manufacturing Technology.

"[@100 million] is a really, really small number in the plan of things for Apple, so this is likely their little toe getting in the water, "he told TechNewsDaily. "And they got nine more toes."

-Pat McGibbon, vice president of  technique and research at the connection of Manufacturing Technology.

Nevertheless, McGibbon regarded the Apple move a sign that the industry may make more industries in the U.S. in the future. He also thinks it's an essential message to other industries. "For manufacturers of the U.S, we couldn't have a better flag than to have Apple coming back." he said.

Would-be Apple employees will likely need a mix of two-and four-year degrees, possibly jprovided in part by Apple, McGibbon added.
 McGibbon's connection represents industries that make work machinery. "Our industry makes equipment that would make Apples," he explained. Such industries have many of the same functions and processes that an electronics industry would, he said.