By Kathleen H 1 February 28, 2017
The repair that they provide to their clients is really amazing to say the least. The price fits the budget and the repair is fast. ...read more
By Angel Cowly January 13, 2016
HTM lighting has become my favorite as they have high quality products and are reliable. I am using LED tubes and bulbs at my residence and am happy with its performance. ...read more
By jasonwinters111 May 01, 2014
Derrick was able to come out to my location and setup a new server for me. Once he told me about Virtual Desktops and how it could save me money from buying new workstations, I told him to move forward with that. I couldn't be happier! I can deploy new users with ease and manage my employees Windows accounts with flexibility I did not have before! Thanks again Derrick, your solution was exactly what I needed and the price was very affordable! ...read more
Created by electric current and magnetic dipoles, a magnetic field is a force field that is all pervasive but cannot be seen or heard (we can measure the strength of the fields with instruments like Gaussmeters, or compass, though). It has a specific direction and a magnitude with which it exerts a force on moving charges and magnetic dipoles present in the same environment. Apart from the Earth itself, magnetic fields may result from transformers, electric power lines, and amplifiers. In fact, according to Maxwell’s equations, these fields can originate from just about any current flow, and is, therefore, represented by a vector field. These highly-charged fields can never be destroyed. You can only redirect the force using the appropriate magnetic shielding materials. Magnetic shielding materials re-direct a magnetic field to reduce its influence on the surrounding. As we said earlier, you cannot destroy or eliminate magnetic fields, so shielding does not attempt to do that. Various shielding technologies are aimed at providing an easy path for the magnetic field to complete its circuit. Effective shielding helps to isolate sensitive apparatus from these electromagnetic fields. In Physics, these shields are conceived as a magnetic field conductor. Today's engineers are concerned about protecting sensitive electronics from low-frequency magnetic fields. As a first step to developing an efficient shielding solution, they try to take an accurate measurement of the magnitude of the field and the area to be shielded. The next step involves identifying the materials that can provide the best path for magnetic fields and thus protect the chips residing within it. Here are the three principles that act as a guiding force for building an effective magnetic shield: Finding the Path With the Least Resistance The materials that have the highest magnetic-permeability offer the most straightforward path for magnetic fields. Going by this principle, the best magnetic shielding solutions are created by placing a highly-permeable material between an external magnetic field and a circuit. This technique can redirect the field, stopping it from reaching the circuit. However, no material can form a perfect magnetic shield; at best they can only reduce the magnitude of the field or curb their reach to the center of the sphere. Finding Metals With the Appropriate Physical Properties Almost all metals have magnetic permeability. Base metals like nickel have very low magnetic permeability. However, the alloys of the same metal can achieve tens and thousands of times greater permeability. Annealing is a filtering process that helps metals to achieve considerably greater permeability than what it has in its untreated version. For example, pure iron, after going through the annealing process in a hydrogen atmosphere attains a high degree of permeability, although this metal lacks other qualities required to support a good magnetic shielding design. However, an alloy of nickel and iron can achieve a lot higher permeability when fully annealed. Finding the Right Proportion in the Alloy The difference in the content of base and other metal can make a big difference in the shielding material's efficiency level. Consider NiFe alloy in our example – even with a small difference in the distribution of Ni and Fe, the magnetic shielding capability of the resultant substance can dramatically vary. For example, when the alloy has 80 percent Ni and 20 percent Fe content, the alloy will not be suitable for magnetic shielding and will be more appropriate for use in applications like transformers or recording heads. On the other hand, iron-rich metals like NETIC may not achieve the same permeability levels of high-Ni materials, but they have one unique advantage—they have some high-saturation characteristics that considerably enhance their attenuating capabilities. In this digital era, the need for curbing magnetic fields has increased rapidly. Against this backdrop, engineers and scientists strive to identify more and morematerials that can offer reliable magnetic shielding capabilities.Much of their efforts involve the creation of high-attenuation materials by combining diverse types of alloys. ...read more
By Leader Tech Inc December 28, 2017
Elastomer products when stretched return to their original form without getting bent, distorted or deformed. Once the external force is withdrawn, you can reuse elastomers because they are not easily damaged. The polymers are classified into two broad categories— saturated (that you cannot cure through vulcanization) and unsaturated (that can be cured by vulcanization). The rubbery material is known for its elastic properties that make it more versatile and usable. Whether it is a small, insulated nozzle or a large elastomer roller, engineers create custom material based on specific industry requirements. The polymers come with many advantages. Here are five of the most important benefits: 1. Inherent Compressibility Elastomeric parts come with inherent compressibility which is particularly useful when mechanical bonding becomes necessary. It comes as little surprise that elastomers are widely used in manufacturing seals and gaskets that seek to ensure full system isolation by providing a continuous surface to even uneven edges. Another essential property of polymers is its chemical resistivity. It is useful in engine casings and pipes that carry acerbic chemicals and material-degrading fuels. 2. Shock Absorption Though a steel enclosure is mechanically sturdier than polymers, it lacks the ability to absorb shocks. Elastomers score better in this respect because they can manage shock events without damage. These products are used to cover metal housings as well as unconnected equipment components in quarries and mines to protect metal casings and to prevent them from deformation. Elastomeric surfaces efficiently counteract abrasion. The polymers are also resistant to wear and tear even when struck with fine aggregate matter or bigger mineral-laden rocks. 3. Electrical Conductivity and High-Temperature Resistivity Elastomer products are developed and used in many industrial applications due to their electrical conductive property. When used in extreme temperature conditions, the material retains its original color and shape. They do not wear away or change their texture or look when exposed to the sunlight, water, or environmental gases. You will also find ethylene acrylic elastomers that are resistant to synthetic engine oils and mineral-based oils at extreme temperatures of 302 degrees Fahrenheit or more and minus 40 degrees Fahrenheit. The polymers perform well in new and hostile automatic transmission fluids. 4. Insulation Elastomers are also used to insulate pipes. When it comes to closed-cell elastomeric foam insulators, they have taken the industry by storm, and are used in many industrial and home applications of rubber to utilize its outstanding closed-cell characteristics. It is beneficial for reducing operating expenses and green living. 5. Resistant to Deformation Equipment drive belts come with long molecular chains that are cross-linked to protect the belts from damage or deformation. These belts also offer mechanical force. With all these properties incorporated, you will be able to fit motors and drive systems with products that are flexible, durable, and retain their original shape and appearance despite continuous start or stop cycles, which are part of mechanical operations. Elastomers are strong and can bend without breaking and help machines to operate. And these include conveyor belts that turn through mining complexes. Whether used in industrial applications or for EMI shielding,choose quality elastomer products. Besides being resilient, polymers are known for their electrical insulation, thus making it ideal for EMI shields, and replaces metal sheets. Elastomeric products can reduce the compression in a shield and thus enhance its efficiency. They are more durable than typical metals such as nickel or copper. Elastomeric shields are used in military applications as well and protect them from unwanted interference. An elastomeric product’s ability to blend with concrete and its chemical resistance makes it usable in a range of industries and applications. ...read more
By Leader Tech Inc September 25, 2017
There has been a growing demand for microwave circuitry designing and development to reduce product size, eliminate unwanted radiations, avoid cross talk, cut back on the cost of production, and achieve electromagnetic compatibility (EMC). All this has created the need for board level multi-cavity shielding. Although the labyrinth and lid shielding approach has evolved as a popular method, there are other alternatives to it. These include a large number of shielding cans and labyrinth pulverized from solid metals such as aluminum. If you use multiple cans, there may be a significant increase in the printed circuit board real estate due to dual tracks for every can as well as the space needed between the containers for adjoining spring finger fittings. There are issues with the labyrinth approach as the wall shall be much thicker than the photochemical machining process. Consequently, the connection to the printed circuit board will not be effective like a seam-soldered joint. Read on to learn about the methods associated with screening enclosures. Use of Base Material You can pick out a base material depending on the incidence and type of the emitted signal that the labyrinth must shield. We recommend that you use a non-ferrous material for controlling electromagnetic interference (EMI) and high frequencies. However, you can use ferrous materials for lower frequencies. Plate Finishes You will need plating finishes to help in solderability, check oxidation, help in radiation reflection, and improve surface conductivity. If you want the enclosures to be properly soldered using reflow or any other methods, the plate finishing should have a melting point apart from that of the solder. Non-Ferrous Materials for High-Frequency Applications If you are using high- frequency devices or applications such as AD or DA converters, microcontrollers, fast logic and switching devices, microwave amplifiers, peripheral devices, and microprocessors, use copper, phosphor bronze, brass, and beryllium-copper, which are all non-ferrous materials. Ferrous Materials for Low-Frequency Devices Low-frequency devices and equipment applications such as electromagnetic coils, wire wound transformers, audio and sonic frequency components, relays, and circuit breakers require ferrous materials like mu-metal, steel, molybdenum, and radio metal. Of these, mu-metal, molybdenum, and radio metal have an innate and delicate magnetic field that is effective in reducing EMI. Material Thickness for High-Frequency Applications You will require a material thickness of about 0.5 millimeters for high-frequency applications. Since these applications function on the principles of reflection, thickness is not much of a problem. There are other aspects to consider like maximizing the connection to the circuit board, choice of a non-ferrous base material, and the assembly quality with respect to soldering to the ground. Photochemical Machining The photochemical machining (PCM) process employs corrosive materials like acids for etching in place of hard-cutting tools. It results in the development of composite profiles using a range of sheet metals such as brass, copper, mu-metal, aluminum, nickel-silver, and aluminum. The benefit of the PCM process is its use of part etching. This method helps to create fold lines that aid in the formation of an EMI shielding enclosure from flat materials. The designers assemble the enclosures with soldered or spot welded joints. The process leads to the formation of complete internal walls with separate lids and intricate labyrinths with spring fingers, screw fittings, or tags. Benefits of the PCM Process There are several benefits of the PCM process. The list includes high-quality finishing, low tooling cost, half-etched bend lines, less modification cost, the potential for tooling several metals, no impact on magnetic properties, removal of stress and burrs, simplified tooling for complicated designs, quick supply of prototypes, and quick turnaround of the original design or its modifications. Avoiding Microphony Problems There are other factors that you must consider while designing enclosures at high frequencies. They are the wave-guide impact on cavities and microphony. You can get rid of these issues with appropriate cavity design and the use of thick materials. You can eliminate the wave-guide effect by choosing the right cavity size and distribution of circuitry in every cavity. The demand for board level shielding solutions has increased with electronic devices and applications becoming smaller and sophisticated. Multi-cavity shielding is imperative for devices with increased digital clock speeds and higher operational frequencies. ...read more
By Leader Tech Inc July 21, 2017
Many people choose to watch their favorite television shows and movies by streaming them over the Internet, but would prefer a larger screen or more comfort while watching. For this reason, some people have connected their PC to the television, allowing them to watch streaming video from the comfort o... ...read more
There are federal rules and regulations that must be followed pertaining to the use of electronics on airplanes. Certain electronics give up signals that interfere with the flight navigation system used to monitor the activity of airplanes. For this reason, it is best to know the rules before flying. ...read more
