Capacitors Blog

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

(1)Because the solid tantalum capacitor is of polar type, do not apply a reverse voltage to it.

(2)The figure on the below shows the relationship between current and reverse voltage.

Suntan Dipped Mica Capacitors are designed to meet the exacting physical, electrical and environmental requirements of the MIL-C-5 and RS-153 specifications.

It is well known that natural mica is extremely stable against heat. Silvered mica is made by printing electrodes on mica film with special silver paste. The silvered films are stacked to the desired value interleaved with metal foils for contact. Then the terminals are clamped on to the element. (The terminals are copper clad steel wires finished with a solider coating for good solder ability). The clamped unit is either dipped under vacuum in epoxy resin and coated with epoxy powder conformably or dipped in phenolic resin and vacuum impregnated with liquid epoxy resin. The envelope thus formed gives high moisture and heat resistance to the unit. This design ensures high reliability and stability.

Careful selection of raw materials and constant monitoring of all equipment and processes provides an overall uniform level of quality consistent with the stringent requirements of today's most sophisticated electronic equipment.

An aluminum electrolytic capacitor consists of cathode aluminum foil, capacitor paper (electrolytic paper), electrolyte, and an aluminum oxide film, which acts as the dielectric, formed on the anode foil surface.

A very thin oxide film formed by electrolytic oxidation (formation) offers superior dielectric constant and has rectifying properties. When in contact with an electrolyte, the oxide film possesses an excellent forward direction insulation property.  Together with magnified effective surface area attained by etching the foil, a high capacitance yet small sized capacitor is available.

Suntan Technology Company Limited
---All Kinds of Capacitors

Effect of Frequency: Frequency affects both capacitance and dissipation factor..

The variation of impedance with frequency is an important consideration in the application of multilayer ceramic capacitors. Total impedance of the capacitor is the vector of the capacitive reactance, the inductive reactance, and the ESR. As frequency increases, the capacitive reactance decreases. However, the series inductance (L)  produces inductive reactance, which increases with frequency. At some frequency, the impedance ceases to be capacitive and becomes inductive. This point, at the bottom of the V-shaped impedance versus frequency curves, is the self-resonant frequency. At the self-resonant frequency, the reactance is zero, and the impedance consists of the ESR only.

Suntan Technology Company Limited
---All Kinds of Capacitors

Of much less concern, yet still important, especially in audio applications, is the micro phonic or piezoelectric effect. Barium titinate which is the base ceramic material for most dielectric systems will exhibit microphonic effects. It is not very difficult to take a Y5V capacitor and put a DC bias with a small signal 1kHz sine wave and get the capacitor to “sing”. Tantalum capacitors exhibit no microphonic effects. The experiment done by AVX involved the opposite phenomena whereby the part was shaken while under bias and the resulting generated voltage was measured. This was done for a series of 1µF devices and the results are shown in Fig below.

Power supply designers are often concerned about the ripple current capabilities of capacitors on both the input and output sides of converters. The biggest concern is the internal temperature rise caused by the I2R power consumption of the capacitor. Since tantalums are a polar device, this ripple should always be accompanied by a DC bias. Since ESR is so dependent on frequency and temperature, the power ratings listed should be viewed as rules of thumb and not laws written in stone. The tantalum capacitors have a published data set for a 10°C rise above the ambient. The experimental set-up used to arrive at this number was emulated and done for a series of ceramic capacitor chips. It should be noted that different mounting techniques can alter the thermal conductivity greatly.

Suntan Technology Company Limited
---All Kinds of Capacitors

Suntan lead the unique and latest technology in manufacturing ceramic trimmer. We specialized in producing ceramic trimmer capacitors with 3mm-SMD Ceramic Trimmer Capacitor, 3mm-Special SMD Ceramic Trimmer Capacitor, 5mm Trimmer Ceramic Capacitor, 6mm and 7mm Ceramic Trimmer Capacitor etc. Following is the applications of a Ceramic Trimmer Capavcitor

Consumer Electronic Equipment
Audio & Visual Equipment -- Home VTR/VCR, VTR Camera, Television set, Video-disk Player, Digital Equipment, Radio Cassette Recorder, Hi-Fi Audio Equipment, Car Audio Equipment, Broadcast Equipment, CATV.

Industrial Electronic Equipment
Tele-communication Equipment -- Facsimile, Key Phone, Electronic telephone, electronic exchanger.
Radio Communication Equipment -- Automobile Telephone, Pocket Pager, Personal Radio.
CPU & Peripherals -- FDD, Computer, Printer, CRT Display.
Office equipment -- Word Processor.
Testing & Measuring Instruments -- Electronic Measuring Instruments, Industrial Measuring Equipment, Medical Electronics Equipment.
Factory Automation Equipment -- Numerical Control Machine, Industrial Robotics, Automatic Equipment, Ultrasonic Equipment, Components for High-frequency Circuit.

Home Appliances / Home Security Devices
Others -- Toys and Electronics Games.

One way to make a large capacitor is to take two long strips of aluminium foil (=large plates), put strips of isolating materials between them, and make a nice compact roll. Capacitors up to around 1MF can be made this way, but they are physically big, so if we want even higher capacity, we need to look for other things than plate area. It happens that we know of a very thin and very voltage resistant type of isolation material: Aluminium oxide. If we cover a strip of aluminium foil with a thin oxide layer, we have one plate and a very thin dielectric. Problem now is to make the other plate come close enough to the other side of the oxide layer. The thing that comes really close to anything is a liquid, so if we submerge our oxide covered plate in a conducting liquid, the liquid forms the other plate, and we can make a very large capacitor. A conducting liquid is called an electrolyte, see?

Metallized Plastic Film Capacitors usually use polyester or polycarbonate as their insulator and are known for their self-healing properties. This means that one of these capacitors can be hit with high-pulsed voltages without seriously damaging the insulation. These capacitors are small and reliable, though it has a lower maximum current holding ability due to its thin metal plates.

Suntan Metallized Plastic Film Capacitors include TS02 ,TS03,TS04, TS05 ,TS07 ,TS08 ,TS09.All these types of Metallized Plastic Film Capacitors

have detailed introduce their Specification , Features . In our suntan website www.suntan.com.hk ,You can find more information about Metallized Plastic Film Capacitors. If you have any enquiry, Welcome to send email to our sales.

Tantalum (atomic number 73) is a dense and ductile metal that is silver-gray in color. It is considered both a refractory metal, due to its high melting point of 5,425 degrees Fahrenheit (2,996 degrees Celsius), and a valve metal, due to its tendency to oxidize, which forms an insulating film. For these reasons, tantalum is commonly used in capacitors, or devices that store electrical charges. Cell phones, computers, mp3 players and many other electronic devices use tantalum capacitors, which have several advantages over other types of capacitors.

Tantalum Capacitors can pack a lot of energy into a very compact package. This is an essential quality when it comes to electronic devices, particularly cell phones, mp3 players and portable computers, which have been persistently getting smaller and smaller. Due to their high energy densities, engineers and designers can easily mount tantalum capacitors into the tiniest of circuits, without having to sacrifice energy output. According to engineersedge.com, a tantalum capacitor rated at 10-microfarads (which are units of capacitance, or the ability of a device to store a charge) can produce the same amount of voltage as a 100-microfarad aluminum capacitor.