Capacitors Blog

Capacitor is an electromechanical device capable of storing electrical energy (electrons). It differs from a battery, as a battery produces electrical energy as a by-product of chemical activity. A capacitor can function in a circuit like a battery. Or a resistor, or an inductor, for that matter. It can also absorb energy, turning some into heat.

A farad of capacitance is a lot of capacitance. In high voltage, we generally deal in microfarads (mfd.) or picofarads (pf) which are one millionth of a farad and one millionth of 1 millionth of a farad, respectively. Infrequently used, a nanofarad is one thousandth of a microfarad.

Photo: Inside, an electrolytic capacitor is a bit like a Swiss roll. The "plates" are two very thin sheets of metal; the dielectric an oily plastic film in between them. The whole thing is wrapped up into a compact cylinder and coated in a protective metal case.

Warning: It can be dangerous to open up capacitors. First, they can hold very high voltages. Second, the dielectric is sometimes made of toxic or corrosive chemicals that can burn your skin.

A capacitor is a bit like a battery, but it has a different job to do. A battery uses chemicals to store electrical energy and release it very slowly through a circuit—sometimes (in the case of a quartz watch) it can take several years. A capacitor generally releases its energy much more rapidly—often in seconds or less. If you're taking a flash photograph, for example, you need your camera to produce a huge burst of light in a fraction of a second. A capacitor attached to the flash gun charges up for a few seconds using energy from your camera's batteries. (It takes time to charge a capacitor and that's why you typically have to wait a little while to take a flash photo.) Once the capacitor is fully charged, it can release all that energy in an instant through the xenon flash bulb. Zap!

Capacitors come in all shapes and sizes, but they usually have the same basic components. There are the two conductors (known as plates, largely for historic reasons) and there's the insulator in between them (called the dielectric). The two plates inside a capacitor are wired to two electrical connections on the outside called terminals, which are like thin metal legs you can hook into an electric circuit.

Suntan Technology Company Limited
----All Kinds of Capacitors

A vacuum variable capacitor uses a high vacuum as the dielectric instead of air or other insulating material. This allows for a higher voltage rating and/or capacitance value using a smaller total volume. In addition to the higher voltage rating a vacuum dielectric greatly reduces the chance of arcing between the plates. There are several different designs in vacuum variables, the most common geometry of the capacitor plates is usually inter-meshed concentric cylinders. The meshed cylinders are contained within a glass or ceramic vacuum envelope, similar to an electron tube. A metal bellows is used to maintain a vacuum seal while allowing positional control for the moving parts of the capacitor.

Common Applications

Vacuum variable capacitors are commonly used in high voltage applications 5000 volts(5kV) and above. They are used in equipment such as high powered broadcast transmitters, Amateur radio RF Amplifiers and large Antenna tuners.

Other Variations

A fixed value vacuum capacitor. Other variations of vacuum capacitors include fixed value capacitors. Fixed value capacitors are designed very much like the variable versions with the exception of an adjustment mechanism.

Comparison

When compared to other variable capacitors vacuum variables tend to be more precise and more stable. This is due to the vacuum itself. Because of the sealed chamber the dielectric constant remains the same over a wider range of operating conditions. With air Variable capacitors the air moving around the plates may change the value slightly; often it’s not much but in some applications is enough to cause undesirable effects. Another common problem with air variables is dust and insects. Dust collected on the plates or a curious insect can raise havoc. A wandering spider is bound to make fireworks with the open frame design used on most air variable capacitors.

Vacuum variable capacitors are generally more expensive than Air Variable Capacitors this is primarily due to their design and the materials used. Although most use copper and glass some may use other materials such as ceramics and metals such as gold and silver. Vacuum variables also vary in adjustment mechanisms which range from course to fine.

Suntan is a Hong Kong based manufacturer of Ceramic Capacitors. Including High Voltage Ceramic Capacitors, Multilayer Ceramic Capacitors, Ceramic Disc Capacitor, Mini Type Ceramic Capacitors etc.

Suntan Technology Company Limited
----All Kinds of Capacitors

Suntan pictures of Capacitors. Notice that all these capacitors have two wires coming out of them, one attached to each plate.

Suntan is well established and specializes in service and quality with an extensive export and import network. We provide quick turn around for our customers all over the world. Almost 30 years experience with all types of passive components using good materials, state of the art equipment and technology and ongoing QC coupled with extensive R & D assure our customers of the best quality and on time delivery.

Suntan offer many kinds of capacitors. Don’t hesitate to send us inquire to sales@suntan.com.hk .We will show you good quality and best price.

Suntan Technology Company Limited will attend Electronic Americas 2011 in Sao Paulo, Brazil from March 28th to April 1st, 2011

• Fair name: Electronic Americas 2011
• Add.: Sao Paulo, Brazil
• Date: March 28th to April 1st, 2011
• Booth No.: N₁50

On this exhibition, all products will be presented, like metalized polyester/ polypropylene film capacitor including X2 capacitor, MLCC and high voltage ceramic capacitor, aluminum electrolytic capacitor, trimming potentiometer, varistor and rectifier diode.

Welcome to visit our booth to establish or expand our business!

A capacitor, also known as a condenser, is a component in electronic devices. It consists of a combination of three objects. First, a pair of objects called conductors conducts electricity. The conductors are separated by a dielectric, which is a substance that does not conduct electricity. Common dielectrics include substances such as paper, ceramic and plastic.

When an electric current exists between the two conductors, it creates an electric field in the dielectric, which can then store energy. The most effective capacitors employ conductors that are wide and flat, as well as being perfectly parallel, with a very small distance between them.

A run capacitor is a particular type of capacitor. A run capacitor uses the charge stored in the dielectric in order to boost the electrical current providing power to an electric motor. This type of capacitor is created to maintain a charge during constant use of the motor. These capacitors are often found in devices, such as heaters, that are continuously running.

One variety of run capacitor is often used in air conditioners. This type of run capacitor is called a dual run capacitor, and uses two run capacitors for two different functions. In an air conditioner, for example, one run capacitor is used to boost the fan motor, and another is used to boost the compressor motor.

Run capacitors typically are classified at 370 or 440 volts. It is necessary to ensure that the correct rating of run capacitor is installed in an engine. If a run capacitor with an incorrect voltage rating is installed in a motor that requires a capacitor for second-phase energy, it will throw off the magnetic field. An uneven magnetic field will cause the rotor to slow in the uneven spots, which increases energy noise, as well as power consumption, and can also cause performance problems and overheating issues.

A Ball Grid Array makes precise alignment and mounting possible. Before the Ball grid Array packaging, a single circuit board would sometimes require hundreds of pins. This presented a lot of positioning problems. When the assembly was heated, adjacent pins would sometimes get soldered together or form unplanned bridges.

One other advantage of Ball Grid Array packaging over other types of packaging involves heat conduction. A Ball Grid Array has less resistance to heat so heat flows readily from the mounted circuit components to the printed circuit board. This reduces the risk of overheating.

Finally, a Ball Grid Array assembly's contact points (point of contact between the surface solder balls and the printed circuit board itself is not readily apparent. This means greater data and application security.
Of course, a Ball Grid Array packaged integrated circuit is rather inflexible. Rigorous stress on the integrated circuit may cause the balls or the contact points to break off.

The manufacture begins with the basic circuit board, primed and printed. This printed circuit board for BGA has pads made of copper and these are arranged in the grid pattern that the solder balls are designed to have.

After the solder balls have been precisely arranged on the surface of the printed circuit board, the soldering process would begin. Surface mount soldering would proceed through reflow soldering (with the aid of a reflow oven that uses infrared or vapors as the heat source). At this point, the metal alloy balls would melt due to extreme temperatures. As the whole assembly cools, the solder balls will solidify and the package will become firmly affixed to the circuit board.

There is one other common packaging for integrated circuits and this is the PGA or Pin Grid Array. The BGA looks physically similar to a Pin Grid Array package. Both are one-sided; that is, only one face of the semi-conducting substrate is used for printing and mounting of circuit components. Moreover, both have an obvious grid-like pattern. However, the Pin Grid Array uses pins - thus, the name - whereas the BGA uses balls - as it has already been mentioned above. The pins (in the PGA) or the balls (in the BGA) are the materials through which electricity is conducted between the printed surface of the semiconductor board and the surface-mounted circuit components.