3 Types of EMI Shielding

IQS Newsroom — Mon, 22 Dec 2014 21:46:47 +0000

EMI Gaskets

EMI shielding, or electromagnetic shielding, as it is officially called, is the process of shielding an area or component from electromagnetic waves using a barrier of conductive or magnetic materials. This kind of shielding is necessary in a variety of applications, from protecting internal components of computers and other sensitive equipment from electromagnetic waves to protecting workers from harmful electromagnetic waves in a factory setting. EMI shielding companies are extremely important, as they provide many other industries with the ability to protect themselves from damaging electromagnetic waves. Most EMI shielding companies use a variety of shielding materials based on the use of the equipment to protect the space or the equipment from the harmful waves, including:
Sheet metal: The original material used for EMI shielding was sheet metal. It is still used today in many industries to protect an area or space from electromagnetic waves. Usually, the metal is charged with a conductive charge to block the radiation waves from passing through the metal. The conductive surface of the metal prevents the waves from passing through the metal.
Copper or nickel ink: Copper and nickel ink act the same as the thicker sheet metal EMI shields. The main difference between the two shields is the thickness. The copper and nickel shields are painted onto a surface and provide a thin shield for smaller parts, usually in electronic devices, such as computers.
Metal screen: A metal screen must have small enough holes that the radiation waves cannot pass through the mesh. It is rare for a single screen to have smaller holes than radiation waves, but sometimes a combination of several meshes with holes in different locations are used to protect the item from the dangerous waves. Metal screens are often used as part of the safety devices and radiation blocks in a microwave oven.

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A Dimple Can Make All the Difference: Metal Dome Design

IQS Newsroom — Fri, 20 Jun 2014 13:32:45 +0000

Metal domes underneath membrane switches help keep the membrane from remaining in contact with the key at all times. The domes also help conduct the electricity through the keypad, sending a clearer signal to the circuits of the unit, preventing misfiring and other problems that can occur when the circuitry is out of alignment. The dome design also retains a high level of buoyancy, which keeps the dome and key popping back into place after every press. These little metal domes are a vital part of any membrane-based design, and most membrane switch systems use domes for the above-mentioned reasons.
However, there has been a problem with the standard dome design for membrane keypad. Most domes are constructed with a raised, rounded bubble that reaches above the corners of the strip of metal. The corners always rest on the keypad, keeping the dome from coming into contact with the circuit board unless the dome in pushed. The metal “feet” on the button must stay in place securely, or else the domes can shift and cause problems with the board.
Unfortunately, with extended use, many of these domes will shift or move over time. This makes them difficult to use, and it is also difficult to fix this issue without replacing the entire keypad. One clever solution to this problem has been the addition of a second dome or dimple placed in the center of the original dome, which can reduce the need for a keypad actuator. The actuator normally controls the keys as they are pressed to ensure that they only apply pressure to the designated key, rather than to surrounding keys or buttons. The dimple on the surface of the dome helps keep the key in proper alignment and makes precise accuracy in the placement of the dome or keypad actuator unnecessary.

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The History of Electric Heating

IQS Newsroom — Tue, 17 Jun 2014 13:31:28 +0000

Even though it seems like heaters have been around forever, this is not the case. In fact, just about 100 years ago only a select few households had central heating systems in their homes. However, the history of the electric heating element goes even further back.
Alexander Graham Bell invented the first electric heater in the late 1800s. He created a metal box with high-powered light bulbs inside that radiated heat into the room. Needless to say, this heater was dangerous and inefficient at filling a room with heat.
It wasn’t until 1905 that the evolution of heaters started to pick up. Albert Marsh invented the chromel heating element, which was much more efficient and creating and dispersing heat than a light bulb. Because of his invention, Albert Marsh is known as the father of modern electric heating. From the invention of the first heating element, electric heating took off and soon began to overtake fuel-based heat sources. In just 30 years, many new homes and businesses had central heating systems based on the original design of Albert Marsh.
The modern infrared heating element still uses the basic principle of Albert Marsh’s original design. However, modern materials, such as ceramic and NiChrome, have a much higher efficiency rating, a longer element life, and are much safer than the designs from 1905.
Today, it is possible to use several different forms of electric heaters for a wide variety of uses. Electric heaters are used in central air heating systems, supplemental indoor heat, outdoor heating, stoves and toaster ovens, manufacturing and product production, automobiles, and in thousands of other places across the globe. If Albert Marsh were still alive today, he would be surprised and humbled at how his invention has affected nearly every part of the modern lifestyle.

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The 3 Types of Heating Element Manufacturers

IQS Newsroom — Mon, 18 Nov 2013 18:31:35 +0000

Heating elements are essential to the operation of any heater. The heating element is the main source of heat production in any heater. In electric heaters, the heat is produced by a heating element powered by electricity. The heat is then distributed through resistance heating, induction heating, or electric heating. Depending on the type of heater, different heating element manufacturers will create different heating elements.
In general, there are three main kinds of heating element manufacturers. Some manufactures create several types of heating elements at their facilities, while others create one type of heating element or heater. It all depends on the company and what they produce. However, no matter what the manufacturer makes, they will make at least one of the three following heating element types:
NiChrome coil or ribbon: NiChrome is a mixture of nickel and chrome. NiChrome heating elements is often used in resistance heating elements. The metal is both flexible and strong, and has the capability of holding high temperatures. Even while white hot, the metal will not oxidize, which is why it remains a popular choice for heating elements for any use.
Sealed ceramic: Sealed ceramic is perhaps the most stable form of heating element. Ceramic heats quickly and retains heat for extended periods, making it one of the most efficient forms of heating elements. Many ceramic heating elements also contain NiChrome metal inside, which helps heat the ceramic from the inside.
Incandescent quartz tubes: Incandescent quartz tubes are exactly what they sound like. These heating elements are basically tubular incandescent bulbs with quartz inside to help maintain the heat. This kind of heating element is most often seen in radiant heating systems where the production of heat requires a gentle approach to prevent overheating.
When you look for a heating manufacturer, ensure they manufacturer the correct heating element for your needs before starting a relationship with that company.

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4 Types of Keyboard Switches

IQS Newsroom — Thu, 14 Nov 2013 21:17:53 +0000

Keyboards are highly useful for a variety of tasks, from computers, to complicated industrial machines, to keypads for security locks and door closures. There are actually a variety of keyboard switch types, which are ideal for different kinds of circumstances and uses. Some of the most popular forms of keyboard switches include the dome switch, scissor switch, mechanical switch, and the buckling spring keyboard switch. Each type of switch is slightly different and provides different advantages.
Done switch: Dome switches combine the properties of membrane and mechanical switches. A membrane switch basically consists of a small membrane pressed onto a circuit board, which then connects a circuit and performs an action. The dome switch places a small, flexible dome above each key that touches the circuit when pressed. Usually, a dome switch has a membrane over the dome to protect the keypad.
Scissor switch: The scissor switch is a more complicated version of the dome switch. A scissor like joint under the key helps press the key into place when pressed. The scissor switch depresses a rubber dome quickly and efficiently, which makes scissor switch keyboards require less space between keys. This helps keep the keyboard cleaner and free of debris.
Mechanical switch: A mechanical switch is one of the original forms of keyboard switch. In a mechanical switch, each key has its own switch directly under the key. This makes it less likely that the keys will fail, but they are also harder to manufacture. Few modern keyboards use mechanical switches, but some still do.
Buckling spring switch: A buckling spring switch is one of the original forms of keyboard switches as well. Old typewriters often used this switch style. Each key has its own individual hammer, which hits the key and causes the key to engage. This gives each key a satisfying indentation and sound when the key is pressed.

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Step Up Transformers for Reliable Power

IQS Newsroom — Fri, 15 Mar 2013 12:06:09 +0000

As a society, electricity is in some ways our life blood. Relying on electricity for work, communication, industry and travel are only some instances that are affected. To properly operate, not all electronic products need the same amount of power. In some cases, it is necessary to increase (step up) electromotive force (EMF) or voltage. In order to accomplish this task a step up of power from a transformer is needed. There is a variety of step up transformers that are able to accomplish this effort and each is of varying size. Large transformers seen outdoors on electrical poles or outside of power plants are amongst the larger transformers. On the other hand, they may be as small as a transformer that plugs into a wall that is used to convert power for an x-ray machine that requires more voltage than a standard socket offers.
In order to accomplish the proper step up needed to operate. The principle of electromagnetic induction is necessary. However, before the EMF or voltage can be changed there must be a step up transformer to perform the task. Alternating current or AC is necessary to the use of transformers, opposed to direct current (DC). Faraday’s Law of Induction explains the process of changing magnetic fields into an electric current in a wire and vice-versa. A pair of wire coils is wrapped inside of the transformer. Theses are referred to as a primary and secondary coil. The primary takes in the current and the secondary sends it out with higher voltage. The amount that the current is stepped up is dependent on the turn ratio of the primary to the secondary coils, this ratio will determine how little or great the voltage will be upped.

Photo Courtesy of Johnson Electric Coil Company

The entire electrical grid runs on alternating current and one of the main advantages is the use of transformers. As electricity moves throughout the power grid it loses some of its momentum to keep a consistent power or voltage needed. Therefore, transformers can provide a step up in power at each point on the grid, resulting in a consistent power source quickly and efficiently. This also allows for the electricity to travel as the voltage is needed and desired at a low cost that is reliable and safe. To ensure safety while utilizing step up transformers precautions have to be made. For instance, with electricity constantly flowing through these devices get hot. To keep them cool oil baths or fans are used along with metal that is able to withstand high temperatures.
Regardless of the size, transformers bring us the electrical power needed to function with our devices we need, want and love to use. From small socket transformers used while traveling or at the doctors to large step up transformers outside of a power plant, each is necessary to power the world efficiently and effectively. The next time you are out and about or in a plant that utilizes transformers see if you can point one out. To successfully use the amount of electricity desired, step up transformers are essential for safe, reliable and ready use.

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Advantages of AC-DC ‘Brick’ Power Modules

IQS Newsroom — Wed, 08 Jul 2009 17:08:00 +0000

by Mel Berman, TDK-Lambda Americas
Compact DC-DC converters have made their way into millions of electronic products and systems. The vast majority of these depend upon an AC-DC power supply (metal box or chassis-mount) to convert the AC into a DC voltage from which the converters can operate. In addition, regulations have mandated that these power supplies include Power Factor & Harmonic Correction (PFHC) to maximize the available power from the power grid. Add to this the need to be as small as possible and to operate with in harsh ambient temperatures and the designer is faced with a problem that is not easily solved.
Traditional Distributed Power Solutions
Traditional designs that employ distributed power architecture place DC-DC converters on PC boards very close to the point-of-load to maximize system speeds and efficiencies. To power the DC-DC converters, the required AC-DC power supply with PFHC is typically mounted somewhere in the system’s enclosure, external to the main pc-board (Figure 1).

This technique is quite reasonable for most applications. However, when it comes to equipment that must be mounted outdoors and occupy the smallest possible volume, there are now improved power products available.
Improved Power Distribution Methods (2 Brick Solution)
Typical medium power (400-700 watts) PCB mounted DC-DC converters are packaged in “full brick” sizes (e.g., 2.4” W x 4.6” L x 0.5” H). A number of major manufacturers of DC-DC converters have seen the need for, and are now providing AC input PFHC front ends in brick-formats that are PCB mountable near to the DC-DC converter(s). This has the advantage of placing all the power components on the same pc-board thus reducing the end products size and eliminating the power interconnect wires (Figure 2).

These AC-DC w/PFHC front-end bricks require some external components (capacitors, resistors, etc.), but the space required for these items is small in comparison to the elimination of the external “metal boxed AC front end”. And, these external components can be robotically inserted during the production of the pc-board. An added benefit of utilizing these brick packages is that they can be cooled by means of heat sinks or cold plates (e.g., mounting the brick bases against the system’s cooler metal enclosure).
AC-DC Power Modules (1 Brick Solution)
TDK-Lambda has continued to develop smaller and better power solutions. In fact, in recent times the AC/PFHC brick mentioned above has been merged with a DC-DC converter to form the ultimate power solution; an AC/PFHC/DC integrated brick. These 2-in-1 devices (single brick solution) accept wide range 85 to 265 VAC inputs, corrects the power factor, and provide the DC output(s) to the system. All this is accomplished within the same size constraints of a single “full brick” package measuring only 2.4” W x 4.6” L x 0.5” H, thus providing a 50% board space savings (Figure 3).

These integrated 2-in-1 pcb-mounted single power bricks are ideal for Distributed Power Architectures where POL (Point of Load) Converters are needed. Since the 2-in-1 Power Bricks provide the conversion from AC to DC (with PFHC) along with the needed isolation, and the Intermediate Bus Voltage, the use of multiple low-cost, non-isolated POL converters becomes quite practical (Figure 4).

In order to increase power densities, special permalloy cores have been developed and employed in the transformers and inductors. New substrates and innovative transformer winding techniques have facilitated component height compressions and improved thermal management. And, of course, advances in integrated and hybrid circuits have contributed greatly to this next generation of power products.

Applications of “Single Brick” AC-DC Power Modules
These new “single brick” AC-DC power bricks are ideal for outdoor and indoor applications including:
· Custom Power Supplies
· PCB Mounted Bulk Power for Multiple DC-DC or POL Converters
· Large LED & Liquid Crystal Displays
· Traffic Information, Control, & Signaling Equipment
· Toll Devices
· Pico & Cell Phone Repeaters
· WiFi, Broadcast & Telecom Sub-Stations
· Underwater Surveying Devices
· Automatic Pass-Reading-Devices for FastTrac Car Lanes
· Oil Pumping & Pipeline Monitoring Devices
· Security Systems
Specifications for “Single Brick” AC-DC Power Modules from TDK-Lambda
TDK-Lambda designed and developed a new range of integrated “single-brick” AC-DC power bricks, their PFE Series. These pcb-mount devices are so innovative, they have seven patents pending.
Some of the salient features of TDK-Lambda’s single-brick AC-DC PFE Series power modules include:
· Low Profile, Single-Brick Footprint
· High Power Density (up to 129W/in3) & Efficiency (up to 90%)
· Regulated and Isolated DC Outputs: 12V, 28V, 48V and 51V
· Output Power Ratings: 300W, 500W, 700W and 1000W
· /-20% Output Voltage Adjustment Range
· Over Voltage/Current/Temperature Protection
· Approved to UL/CSA/EN60950-1, CE Marked, & RoHS Compliant
· Heatsinks & Evaluation Boards/Kits Available
· Adaptable to cold-plate cooling without a fan
· Wide Operating Temperature Range: -40°C up to 100°C (at base)
· Operates from Universal 85 to 265VAC, 47-63Hz Input (440Hz operation possible)
· Power Factor & Harmonic Correction Meets EN61000-3-2
· Active Current Sharing for Paralleling up to 6 modules is available (see PFE500F & PFE1000F series)

Photo of Lambda’s PFE 700-watt AC-DC Power Module

PFE Series Power Module mounted on Evaluation Board with heatsink and external components

For detailed information about the PFE Series power modules and the available accessories including evaluation boards, heatsinks, pc board layouts, etc., please visit this website:
http://www.us.tdk-lambda.com/lp/products/pfe-series.htm

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