answersLogoWhite

0

📱

Consumer Electronics

Ask questions here about the electronics you use every day: from phones and computers to kitchen appliances and radios.

4,952 Questions

Can a rectenna system recycle modulated 0 Hz to 100 Hz ambiant rf and microwaves and how big would it have to be to keep a house clean of rf and microwave pollution?

School's in. Ring the bell. First, let's jump around spotlighting the elements of the question so we understand them all. The rectenna (rectifying antenna) is a device that is really good at converting microwaves to DC. It's highly frequency sensitive and directionally sensitive. That means it only works on one frequency (or an extremely narrow range of frequencies) and rejects all others, and it's critical where the rectenna is pointed. The rectenna doesn't recycle, it converts. Antenna setups make the rectenna work even better. DC is, of course, direct current, like the uni-directional current flow from a battery. Microwaves are electromagnetic waves of really high frequency. Radio frequency (rf) waves are lower frequency than microwaves. Ambient rf (radio frequency) and microwaves are the rf and microwaves that we are bathed in every day. They're like the electromagnetic equivalent of air pollution. Sources are cell phone energies (both from the cell hub transmitters and the phones themselves), leakage from microwave ovens, the microwave energy beamed down from space, signals from radar, energy from imaging equipment,.... There's a lot of sources. And of extreme importance is that the pollution covers a wide range of frequencies. Modulated 0 Hz to 100 Hz waves are nowhere close to rf, let along microwave frequencies. They're like, bottom of the electromagnetic spectrum, and rf and microwaves are close to the top. Modulation can be simply described as the "adding of information to" a signal. Modulating a wave is adding information or intelligence to a carrier wave. We've covered everything in the question. Now to the answer. A rectenna system cannot keep a house clear of rf and or microwave pollution. The pollution comes in at many different frequencies, and the rectenna is highly frequency sensitive to a tiny range of microwave frequencies. And the pollution comes in through all the walls, doors and windows. A rectenna cannot even clear a house of all the signals on the frequency at which it is tuned (owing to scattering of the electromagnetic energy), even if it is pointed at the source. And no matter how big the antenna. A modestly useful analogy would be trying to completely darken the inside of an all-glass house on a bright day. Light is electromagnetic energy like microwaves and rf, but of even higher frequency. All-glass here because microwaves go through walls and roofs, and we need our analogy to work sorta like them. If we approached our "darkening" project by just using light absorbing materials all around the house in the different rooms, we'd be largely unsuccessful. It would be better to just coat all of the outside (including all windows) with a thick layer of paint. Everything. All of it. Because any window or even a large crack will let in light. Nothing inside a house will "keep a house clean of rf and microwave pollution" regardless of the cleverness of the inventor. Want to keep out microwave pollution? Cover your entire house top to bottom in a seamless sheet of aluminum foil. That'll work. As an aside, the 60 Hz AC energy on the power grid is hooked up to your house. Your house is bathed in fields generated by 60 cps AC. All day. Everyday. (And you doubtless grew up bathed in these fields.) The field strength of the 60 cps energy is probably as high if not higher than the field strength of ambient microwaves. This for dense urban areas. If you live in the suburbs or rural area, the 60 cps electromagnetic bath you are living in represents a far higher "dose" of electromagnetic energy than you'll be getting from cell phone transmitters. And it has done nothing to negatively affect your health. To now. Ignorance was bliss.

Who designed the Logica sewing machine?

Giorgetto Giugiaro. Famous car designer. Doing a project on him at university but can't find a picture of this sewing machine

Where are variable resistors found?

dimmer swithces for lights usually contain variable resistors

Your cassette radio keep chewing up your cassettes?

Most likely it is caused by the dust gathered on moving parts in the cassette player mechanism and/or some misaligned mechanical component in the cassette player mechanism.

- Neeraj Sharma

Actually, a broken rubber belt is the most common problem.

What is a music expander?

An expander works in a similar way to a compressor, with a compressor you set the threshold and when the signal goes over this threshold the compressor starts to work. The signal over the threshold is attenuated (reduced) at the rate of the other parameter settings (ie. attack, ratio, release,etc.). An expander works in an opposite fashion, the threshold is set and any part of the signal dropping below this threshold will be affected by the expander and this level will be raised. The expander therefore like the compressor balances out the signal making it sound more professional.

Who invented the first microcomputer?

1975: Ed Roberts, the "father of the microcomputer" designed the first microcomputer, the Altair 8800, which was produced by Micro Instrumentation and Telemetry Systems (MITS). The same year, two young hackers, William Gates and Paul Allen approached MITS and promised to deliver a BASIC compiler. So they did and from the sale, Microsoft was born.

What song does telus use for the seahorse falls in to place tv commercial?

The song used for the Telus seahorse commercial is called "Fall Into Place", and is recorded by a U.K. band called "Apartment". They are an Indie band, and record on the Fleet Street (U.K.) label. You can find the song, and more information, on the "MYSPACE MUSIC" site.

Is it possible idenfiying bjt and fet on the circuit?

Identifying BJTs and FETs on the circuitIt is in fact possible to identify transistors in circuits. However, this depends on one's familiarity with the different types of BJT and FET constructions. Since the transistor is a three-terminal device, it is easy to differentiate it from other circuit elements such as resistors, capacitors and inductorswhich are all two-terminal devices. The only exceptions to this may include regulators; which though are not transistors are provided with three terminals.

Why logic gates are called as logic gates not boolean gates?

Logic gates are the basic building blocks of digital circuits or systems. these digital circuits are used to implement several combinational and sequential operations. these operations include starage, timing, arithmetic, coding, communication etc. Hence, implementing the boolean algebra is not the only purpose where logic gates are used, hence, it is opt to call them as logic gates rather than boolean gates.

Frank and Lillian Gilbreth biography?

Frank Bunker Gilbreth was born on July 7, 1868 in Fairfield, Maine. He was a bricklayer, a building contractor, and a management engineer. He was a member of the ASME, the Taylor Society (precursor to the SAM), and a lecturer at Purdue University. Frank died on June 14, 1924.

Lillian Evelyn Moller was born on May 24, 1878 in Oakland, California. She graduated from the University of California with a B.A. and M.A. and went on to earn a Ph.D. from Brown University. She earned membership in the ASME, and like her husband lectured at Purdue University. Lillian died on January 2, 1972.

Frank and Lillian were married in 1904 and were parents of twelve children. Together they were partners in the management consulting firm of Gilbreth, Inc.

The following biography of Frank and Lillian Gilbreth was printed in the IW/SI News, the newsletter of the International Work Simplification Institute, Inc., in September 1968. For further reading on the Gilbreths and their family, please consult our bibliography of Gilbreth books.

Pioneers in Improvement and our Modern Standard of Living

IW/SI News, Issue 18, September 1968, pgs. 37-38

One of the great husband-and-wife teams of science and engineering, Frank and Lillian Gilbreth early in the 1900s collaborated on the development of motion study as an engineering and management technique. Frank Gilbreth was much concerned until his death in 1924, with the relationship between human beings and human effort.

Frank Gilbreth's well-known work in improving brick-laying in the construction trade is a good example of his approach. From his start in the building industry, he observed that workers developed their own peculiar ways of working and that no two used the same method. In studying bricklayers, he noted that individuals did not always use the same motions in the course of their work. These observations led him to seek one best way to perform tasks.

He developed many improvements in brick-laying. A scaffold he invented permitted quick adjustment of the working platform so that the worker would be at the most convenient level at all times. He equipped the scaffold with a shelf for the bricks and mortar, saving the effort formerly required by the workman to bend down and pick up each brick. He had the bricks stacked on wooden frames, by low-priced laborers, with the best side and end of each brick always in the same position, so that the bricklayer no longer had to turn the brick around and over to look for the best side to face outward. The bricks and mortar were so placed on the scaffold that the brick-layer could pick up a brick with one hand and mortar with the other. As a result of these and other improvements, he reduced the number of motions made in laying a brick from 18 to 4 1/2.

Frank and Lillian Gilbreth continued their motion study and analysis in other fields and pioneered in the use of motion pictures for studying work and workers. They orginated micro-motion study, a breakdown of work into fundamental elements now called therbligs (derived from Gilbreth spelled backwards). These elements were studied by means of a motion-picture camera and a timing device which indicated the time intervals on the film as it was exposed.

After Frank Gilbreth's death, Dr. Lillian Gilbreth continued the work and extended it into the home in an effort to find the "one best way" to perform household tasks. She has also worked in the area of assistance to the handicaped, as, for instance, her design of an ideal kitchen layout for the person afflicted with heart disease. She is widely recognized as one of the world's great industrial and management engineers and has traveled and worked in many countries of the world.

Frank Gilbreth ws born on July 7, 1868--his centennial should mark a milestone in management and work simplification. By 1912, he left the construction business to devote himself entirely to "scientific management"--a term coined, in Gantt's apartment, by a group including Gilbreth. But to him it was more than merely the mouthing of slogans to be foisted on a worker at a job in a plant. It was a philosophy that pervaded home and school, hospital and community, in fact, life itself. It was something that could be achieved only by cooperation--cooperation between engineers, educators, physiologists, psychologists, psychiatrists, economists, sociologists, statisticians, managers. Most important--at the core of it all, there was the individual, his comfort, his happiness, his service, and his dignity.

By now, too, there was no mistaking the partnership--even though the wife's modesty, reticence, and sex could mislead all but the knowing. However, one accomplishment is strangely the contribution of Frank Gilbreth alone--even though she may have given of herself to make it possible. This construction is perhaps the greatest of all: the development of Lillian Moller Gilbreth. Few marriages thoughout history can match this romance of husband and wife, both whose names have become famous in the same field. The heights that such a partnership can achieve is probably best realized by attempting to name other such combinations--Pierre and Marie Curie, Charles and Mary Beard, Sidney and Beatrice Webb, Elizabeth and Robert Browning. Surely there are not many--but they are impressive.

Throughout his life, Lillian Gilbreth remained, in her eyes, the junior partner. After his death, she said: "I have had more in twenty years than any other woman I have known has had in a lifetime." With him gone, she knew precisely what she had to do: carry on as he would do. This meant family and work. These were tasks for which many of the Gilbreth friends offered their help. Yet these were tasks that she knew she must perform alone. How well she accomplished them--most would say is a tribute to her, her spirit, her character, her intelligence, her strength. All this she would simply and emphatically deny. For to her, it goes without saying, it was simply a tribute to Frank Gilbreth. And who is to say that she may not be right?

"When it comes to the questioning method, of course he shared with all the scientific management group the belief in the value of questions and the need to ask these questions over and over determining how the thing was to be done and why it was done and how the betterment could be brought about."

"The things which concerned him more than anything else were the what and the why--the what because he felt it was necessary to know absolutely what you were questioning and what you were doing or what concerned you, and then the why, the depth type of thinking which showed you the reason for doing the thing and would perhaps indicate clearly whether you should maintain what was being done or should change what was being done."

"This emphasis is a little different from what most people think about Frank and his work, and about the people who worked along these ways. Generally people expect that the most emphasis would be on the where and the when and the how. The how is, of course, in most people's minds very closely identified with motion study, work study, directed energy, work simplification or whatever name is given to this type of work today."

"When he considered the what he thought continuously, not only of the ideal thing that was to be done and the ideal method that was to be used in order to get this done. That of course, was at the base of his favorite concept which was 'the quest of the one best way.' "

It is both easy and difficult to analyze this First Lady of Engineering. She is the epitome of crystal-clear logic--even though she seems to be a mass of contradictions. Trained in literature, she has found her place in engineering. As an engineer, she has found people more important than machines; waging a never-ending war on fatigue. One, watching her unceasing rounds of work, activity, and travel, can rightfully believe that she has created a non-existent foe. An extremely busy woman, she seems to have more time for things than most people. And, as kind and as gentle as she is, she can don armor and do more than hold her ground in defending the right.

We Salute You--Frank and Lillian Gilbreth--as the Fountain Head of Work Simplification. May we, the members of IW/SI, be worthy to bear the torch which you have given to us.

Is it possible to record directly off dvr systems from stores surveillance and if so how?

It should be possible to do what you want to do. Look on the rear of the DVR and see if it has RCA type connectors labeled, "out". There should be a red, white and yellow connector. The red is the right audio connector, the white is for the left audio channel and the yellow is for the compisite video out.

Composite video means that all the signals necessary for something like a VCR to record from and all you need is the appropriate patch cord setup.

It's "out" FROM the DVR to "IN" to your VCR. Just match the colors.

Put a tape in the VCR, locate the spot on the DVR you want to transfer, then hit the RECORD button on the VCR first, THEN the play button on the DVR. Record your video and then stop the VCR's recording. Play back the VCR's recording to make sure you have the video and viola, you're done.

Which company made the first Bratz doll?

Answer

MGAE made the first bratz doll when i was 5-11 i luvv thee bratz dollz

How do you make a electromagnet stronger?

For a simple copper wire around iron nail electromagnet, increasing the number of rounds the copper wire makes around the nail will increase the electromagnet's strength. Also, increasing the voltage applied(adding a battery) will increase the magnetic field.

Can I check the capacitor value by using analog or multimeter?

You can see if the capacitor charges and discharges with an ohmmeter. You can check the value of the capacitor if the multimeter has the facility. With an ESR meter you can establish the value of the capacitor while in circuit.

What are the standard values for capacitors and inductors?

Capacitors come in values from picofarads (10-12 farads) to farads. They can be had in tolerances from .1% to 20%. For a list of standard values in 10% increments, go to http://www.ecelab.com/list-capacitors.htm

Inductors can be had from nh (nanohenrys) to henrys in tolerances from 1% to 20%. For standard values in 10% increments, go to http://www.rfcafe.com/references/electrical/inductor_values.htm

How do you turn off the alarm on a Casio 2926 w 753 watch?

Go to the alarm mode (AL on screen) and press the upper right button. This should turn off all alarms. Continue to press the upper right button to switch between the alarms, being sure to remain in the alarm mode.

What did Luis Alvarez invent?

Alvarez won the 1968 Nobel prize for for Physics "the discovery of a large number of resonance states, made possible through his development of the technique of using hydrogen bubble chamber and data analysis". Specifically, his research made it possible to record and study the short lived particles created particle accelerators. During World War II, Alvarez was a key participant in the Manhhaton Project including Project Alberta on the dropping of the bomb, and in war projects in general. He flew as a scientific observer of the Atomic Bombinh of Heroshima on The Great Artiste. Alvarez and his student Lawrence Johnston designed the exploding-bridgewire detonators for the spherical implosives used on the Trinity and Nagasaki bombs. He additionally did important work relating to radar and aviation, and designed a system by which airplanes could land safely in low visibility conditions, useful both to bombers and commercial aviation. After the war he went on to invent the synchrotron. Alvarez also proposed a jet-recoil theory for the Kennedy assassination to explain why John F. Kennedy's head jerked backwards if Lee Harvey Oswald, shooting from behind the president, was the assassin.

Kx-tg2358bxs Panasonic dial lock reset?

Please contact the nearest office of the company and ask for customer support

Is dynamic contrast ratio important when purchasing a television?

== == Note: The below answer discusses "contrast ratio". "Dynamic contrast ratio" is a feature that automatically adjusts the contrast and brightness based on the darkness of the image. There is some debate as to whether this feature improves or worsens the quality of the display.

Yes, contrast ratio can be very important, especially when looking at LCD Tvs. Because of the nature of an LCDs lighting design, LCD screens have been known for not producing the best "Black Levels", that is, how dark the darkest parts of a video appear to the viewer. Some LCDs can appear to have more of a "gray" black level than a "black" black level, because the light source used to illuinate the LCDs picture can be seen at the borders of the display screen. The white light of the lamp, combined with the black of the LCD, makes the gray color. This is especially the case with very cheaply made LCDs, and even well-made ones with screens larger than 50 inches (for larger size screens, a plasma display might be a better option). OK, enough rambling, so, what is contrast ratio? It is basically a ratio of two values (i.e. 800:1, 10,000:1, etc.), where the first value is the "Brightest" value, and the second value is the "Darkest" value. Contrast ratio is the difference between the brightest white and the darkest black values of a screen. So, if your ratio is 10,000:1, then your display, at its brightest level, will be 10,000 times brighter than if the screen were completely dark. Naturally, the higher the ratio, the better your screen will look when you have the lights off in a room, and, unfortunately, the price of a TV will be higher. So, contrast ratio can be extremely important if you value a high quality image from an LCD display (it does come into play with plasma monitors, but it is not as important because the lighting technology is different). And if you have a good amount of money to spend on an HDTV, why not get a better image? Think about it, your TV is an investment, and if you like watching movies as much as I do, then you'll definitely want a TV that will give you a superb viewing experience for many years to come. I would like to make suggestion: Go into Best Buy or any electronics retailer where you can physically view and handle a bunch of TVs lined up next to each other so you can compare the differences in image quality. Let your eyes be the judge, only I will say pay special attention to the Sony and Samsung LCDs. I think they're the best on the market today! Hope this helps...I know it was a lot:) Happy viewing!