2011年4月19日星期二

Select the microphone cable systems should be the issue

In recent years, both for comfort and energy efficiency reasons, air conditioning and lighting systems are increasingly using electronic digital control technology. The numerical control system wiring in the weak will microphone signal line generated electromagnetic pulse noise.

Microphone cable carrying the signal amplitude range of 1 / 100 V (10mV) ~ 1 / 1, 000,000 volt (1μV) between the wiring cable selection process or a small error in the microphone system may be collected into a big noise antenna.

The following sections summarize by way of Q & A microphone system configuration problems.

Q1. What should be used under the conditions of the two core Mac cable?
Two core cable Mike does not apply to noise as a major consideration and a high level audio signals, can reach-20dB ~ 0dB environment. At this point, the two core cable show their small diameter, low-cost advantage. Of course, if not the line level but the microphone level, it should use the four quad-core cable line.

Q2. What conditions should be used four quad-core Mac cable?
More important factor in the noise, or signal level only-50dB or less environment should use four quad-core Mac cable. And compared the two core shielded cable, this cable can block out 90% of the noise

However, if such a cable with large-capacity power cables along the alignment, in order to secure that it should be penetrated into metal tubes.

Q3. Quad quad cable is not expensive?
The cost of this cable has greatly declined in recent years. Decades ago, only large concert halls and professional radio stations can afford them can be used. In 1981, Canare has developed the cost of using the aluminum foil shield four quad-core cable. In addition to traditional professional equipment other than that this cable in many non-traditional areas such as wedding halls, classrooms and other schools have also been widely used up.

Q4. If you do not use metal conduit, Mike cable should be far away from power cables?
If using metal conduit, can be found from Figure 3 should be left between the cable spacing. Note that if the fabric without regard to discharge the cable spacing problem, are prone to noise problems in the future is very delicate. Since Mike's signal cable is very weak, so it should be possible to use metal conduit.

 
Q5. In the use of current when a very large cabinet, which issues should be considered?
And question 4 (do not use metal duct should be considered in the problem) the same answer.

Q6. Use soft cloth metal conduit cable discharge What are the disadvantages?
Metal hose can reduce the noise, but not as effective metal hard pipe, it is recommended to use metal hose threading the cable line spacing should be left.

 Q7. What is the "wave masking"?
With corrugated metal shield is made of spiral wound around the cable shielding layer formed mainly used for underground cables. The shielding effect between the bare fabric cable and metal pipe threading between the disadvantage of poor flexibility, be particularly careful when bending.

Q8. Mike Cable There are many types, selection criteria, how?
The same types of shielding, they are only on some specific aspects of different uses according to the specific requirements to select the cable type.

Braided copper shield
No matter how many times through the bending, winding, twist, or retractable, shielded copper network can maintain a good shielding ability. As a hand-held cable or extension cable is ideal when using this type. In order to ensure a high shielding ability, which was especially fine cable knit, so than other types of cable costs are expensive, better results. It does not end processing needs of professional experience.

Spiral shield
Spiral copper shield around the cable is tightly wound as spiral. Wound twice around the opposite is also known as "double-helix shield" better shielding. Prices are between spiral shield and foil shield bronze mesh screen between the price. Although no side deal with relatively simple, but very active shielding performance will not spiral down, spiral shield is designed for fixed installation.

Aluminum foil shield
Molten aluminum foil shield is made of polyester film with aluminum foil, aluminum foil with a wound cable. The cable line is not end of treatment simply, the price is also cheaper for fixed installation. The need to pass through metal pipe laying aluminum foil shielded cables, be sure to use the rope filled with variety. When the threading operation, filling ropes to protect cables not due to excessive force and kink or retraction. Aluminum cable is now widely used in multi-function hall, stadium and other environment.

2011年4月18日星期一

HDMI cable description

HDMI: HDMI full name in English is "High Definition Multimedia Interface", which means Chinese High-Definition Multimedia Interface. HDMI interface can provide up to 5Gbps data transmission bandwidth, can send uncompressed audio signal and high-resolution video signals. At the same time without the signal before transmission / A or A / D conversion, can guarantee the highest quality audio and video signal transmission. HDMI and DVI on the pin-compatible, but with a different package. Compared with DVI, HDMI can transmit digital audio signals, and increased support for HDPC, while providing a better DDC optional features.
Introduction
HDMI supports 5Gbps data transfer rate of 15 meters can be transmitted far enough to deal with a 1080p video and an 8-channel audio signals. And because of a 1080p video and an 8-channel audio signal needs less than 4GB / s, so there is great margin HDMI. This allows it to be connected with a cable DVD player, receiver and PRR. In addition, HDMI supports EDID, DDC2B, so has the HDMI device has a "plug and play" feature, the signal source and display devices will automatically be "consultation", automatically select the most appropriate video / audio formats.
Advantages
Consumers the benefits of HDMI
100% Digital
No compression, no conversion
Directly from the source of pure digital picture and sound (you can see and hear)
Video and audio signals from the output device to the display device to keep the number of
The best quality of sound and image
HDTV provides the bandwidth for the
Support for 1080p and higher resolution
More than twice the bandwidth of 1080i
YUV color space to provide support
Just a cable
A cable is included in all HD video and audio
Instead of up to eight audio and video line 5
Reduce wiring complexity
Automatic Format Intelligence *
TV and AV Receivers can adjust without consumer intervention
Video source to receive the display device supports the video format and output the ideal audio and video formats
Display stood to receive from the source video format and aspect ratio image
Consumer Electronics Control *
Entirely from a single remote control of the home theater
Achieve advanced features, such as "one key play"
l      These features are achieved in accordance with manufacturers

2011年4月14日星期四

BTL Speaker cable standard Reference


Unambiguous use of connectors
    From the connectors on the use of terms, BTL Speaker cable standard Reference standard speaker wire, as most high-end market, with the audio industry recognized brand in Germany WBT 0680 Y-type high gold-plated terminals to connect locking manner and with professional class shrink plastic seal tight to prevent oxidation, to ensure the best signal transmission.
    BTL Speaker cable standard Reference standard speaker wire single line rather stout body, heavy in your hand, giving the impression that the full material. In actual use, it is quite strong line body flexibility makes the connection when the device somewhat strenuous, but does not affect the use of touch, a little also with a clever look very smooth when fresh.
    I listen to comments received the Speaker cable standard Reference standard speaker wire line body length of 3 meters, which for the environment than the wide use of speaker positioning to provide a convenience, practicality is obvious. In the "burn line" process, I try to use it to connect to a combination of several sets of got used to feeling it fit for the excellent performance of enclosed can surprise people. The formal hearing comments, I choose the equipment it has: Exposure (Lippo sound) MCX flagship CD player and amp, PMC PB1i speakers; with the signal lines and power lines have the same application BTL products that Excel Reference Silver Standard Aerospace and Aeronautics Standard Reference signal line space silver standard power cord.

Pure sound without dyeing
    Speaker cable standard Reference speaker cable conductor as applied to high-tech materials, using insulation and excellent dielectric isolation layer, using the powerful military-grade shield, so it is transmitted out through the voices of most of the pure non-staining, both listening to what music can bring a quiet background, easy to bring out the scene in a variety of instruments and voices of real texture.
    The other direct feeling for me, this speaker wire is very wide intervals of frequency response, both ends of the extended well, so that the continuity of music and to each other very much in place, the air being very prominent, like the whole 3D feeling and the end is particularly striking force This feeling is like the glasses to wipe the screen clean, bright and clean, comfortable and cozy and very dynamic.

Rhythm sounds fine, dense texture charming
    Do not think that line is brilliant shining silver, angular, or treble will be killing one another, in the space I have heard BTL series of several silver wire is no such phenomenon; Speaker cable standard Reference speaker cable like this, it is not take a very long pot cooked, China and the United States will be able to issue transparent, slim not skinny treble natural texture. As I use the EMI published "Perlman Violin Selected Essays," Listen, it expresses a very high-frequency extension of the violin and the air being very good, unlike some of petite silver line is so stressed, but showed delicate, easily , flexible direction, pull the sound of the piano playing delicate, dense texture and rich string sound tension, rosin charm appear exhaustive. This rich fresh water has a transparent high-frequency, even under a large volume, and also give some flexibility, comfort.
IF this line extremely well, particularly its density being very convincing, both clean and smooth rounded so fun. In interpreting the human voice singing such as Jenkins's "heart song" and Andrea Bocelli's "love", the song of the band has a sufficient thickness, and no cold or sharp discomfort, and precise image and Convergent Morphological structure of the mouth-type show clearly the three-dimensional planning, and filled with a silver line of a rare and pleasant warmth.

2011年4月8日星期五

Advantages of coaxial cable

Coaxial cable is very special, may be called "High King." 600MHz regarded as the limit of the twisted pair, and the coaxial cable, this is only a mere trifle.

Coaxial cable and wire in the rate of the signal around the material (dielectric) is directly related to the choice. Using solid polyethylene transfer rate is 66% of the speed of light using 78% polyethylene foam, a new nitrogen into the (nitrogen-gas-injected) dielectric is 86%, shown in Figure 2. Use of this material means that most of gas within the cable. However, as small bubbles, the density of plastic is still high, the bending wire cables can remain in the center.

In the twisted pair of wire bonding method is sometimes used for coaxial cable, this method can make it smaller, lighter and cheaper. Also, because no plug, and more simple to install. As the bonding process does not use glue, peel without glue residue, and no extra plastic. Cut with pliers, the hand will be able to separate coaxial cable. This coaxial cable can reach 3GHz, can be used in analog or digital video, RGB, and can achieve even higher resolution QXGA VGA