Suntan Blog

The capacitor (C) in the circuit diagram is being charged from a supply voltage (Vs) with the current passing through a resistor (R). The voltage across the capacitor (Vc) is initially zero but it increases as the capacitor charges. The capacitor is fully charged when Vc = Vs. The charging current (I) is determined by the voltage across the resistor (Vs - Vc):

Charging current, I = (Vs - Vc) / R   (note that Vc is increasing)

At first Vc = 0V so the initial current, Io = Vs / R

Vc increases as soon as charge (Q) starts to build up (Vc = Q/C), this reduces the voltage across the resistor and therefore reduces the charging current. This means that the rate of charging becomes progressively slower.

Ceramic capacitors have become the preeminent, general purpose capacitor, especially in SMT chip devices where their low cost makes them especially attractive.  With the emergence of thinner-dielectric, multilayer units with rated voltages of less than 10 V capacitance values in the hundreds of microfarads have become available.  This intrudes on the traditional, high-capacitance province of aluminum electrolytic capacitors.

Ceramic capacitors are not polarized and therefore can be used in AC applications.  The low DF and high capacitance stability of Class 1 and 2 are especially suited to AC and RF applications.

On Mar28, Suntan went to Sao Paulo, Brazil for the "Electronic Americas 2011". During Mar 28th to Apr 1st 2011 in Sao Paulo, Brazil. Suntan sales met many old and new customers. Booth No. N150 was very beautiful and professional. The red posters made visitors very excited,more and more customers went to our booth and have a look at our good quality electrical samples, Our "Suntan"  brand products enjoy a very good reputation in Brazil market. Suntan exhibited successfully in "Electronic Americas 2011"

We showed our products such as metalized polyester/ polypropylene film capacitor including X2 capacitor, MLCC and high voltage ceramic capacitor, aluminum electrolytic capacitor, trimming potentiometer, varistor and rectifier diode. All these products attracted many people attention, This time, we win more new customers and some even placed order at our booth!

We also have these products in our stock now, If you have any inquiry, please fell free to contact our sales .Following is the pictures of our beautiful sales at our booth.

The capacitance of certain capacitors decreases as the component ages. In ceramic capacitors, this is caused by degradation of the dielectric. The type of dielectric and the ambient operating and storage temperatures are the most significant aging factors, while the operating voltage has a smaller effect. The aging process may be reversed by heating the component above the Curie point. Aging is fastest near the beginning of life of the component, and the device stabilizes over time. Electrolytic capacitors age as the electrolyte evaporates. In contrast with ceramic capacitors, this occurs towards the end of life of the component.

Capacitors, especially ceramic capacitors, and older designs such as paper capacitors, can absorb sound waves resulting in a microphonic effect. Vibration moves the plates, causing the capacitance to vary, in turn inducing AC current. Some dielectrics also generate piezoelectricity. The resulting interference is especially problematic in audio applications, potentially causing feedback or unintended recording. In the reverse microphonic effect, the varying electric field between the capacitor plates exerts a physical force, moving them as a speaker. This can generate audible sound, but drains energy and stresses the dielectric and the electrolyte, if any.

The Decoupling capacitor is used to decouple the IC from the power source. The By-Pass capacitor reduces the trace length from the power source to a trace length from the IC to the decoupling capacitor ~ a reduction from many inches to less then an inch. A reduction of 20nH an inch in trace inductance is achieved by introducing a decoupling capacitor in between the IC and its power source. Assuming the power source is a regulator 12 inches away, and the by-pass capacitor is placed within an inch of the IC, the trace inductance is reduced from 240nH to 20nH.

There are many types of Capacitors in Suntan Technology Company Limited’s stock.This Capacitors are widely used in many areas in this Computer Times.Suntan Ceramic Capacitor arte wide applicable in computer, data processor, telecommunication, industrial control, and instrumentation equipments, etc. And built by superior moisture and shock resistant epoxy coating, can be supplied in both bulk or tape and reel package for automatic insertion in printed circuit board.

TS15 is one type of Ceramic Capacitor, it also called Ceramic Disc Capacitor.TS15 has the following Features

Linear temperature coefficient of capacitance
High stability of capacitance
Low loss at wide range of frequency

Our Capacitors are sold all over the world, With the high quality and competitive price and short delievery, We have a popular market overseas. For our other Capacitors ,please visit our website www.suntan.com.hk .And if you have any inquiry , welcome to contact our sales for your reference.

A varistor installed at an intermediate point of a power system, downstream from the service entrance, is exposed to a combination of surges: internal surges from load switching within the building, and residual surges from external lightning surges. The frequency of occurrence of these surges has been the subject of many sweys of which a recent publication is representative . In all these surveys, the steep rise in the number of occurrences of surges of lower amplitude is quite remarkable. In other words, a varistor attempting to clamp at lower surge levels will be required to divert a much greater number of surges than a varistor selected with only slightly higher voltage rating. The varistor with the lower clamping voltage will expend its puke rating faster than a varistor with higher clamping voltage.

Torque

The torque test should be done by rotating the rotor through one full turn within 15~100gf.cm. Please noted that it might cause the torque will decrease against the rotation increase

Vibration

The maximum capacitance was set at 80 to 90% , however it shall be subjected to vibration test at 1.5mm amplitude, with frequency range from 10 to 55 Hz ,and  then return to 10 Hz for 1 minute applied for 2 hours in each of three mutually perpendicular planes. (total 6 hours) The capacitor shall be rigidly mounted by their normal mounting means .The vibration capacitance shall be within  ±0.25pF or ±2% ( whichever is greater ).

The tantalum foil capacitor was introduced around 1950. It was developed to provide a more reliable form of electrolytic capacitor without the shelf life limitations of the aluminium electrolytic capacitor. It was able to be developed as a result of the availability of high purity tantalum foils and wires. Initially plain foil variants were introduced, but this was quickly followed by etched variants.

The purity of the materials used plays a major part in determining the leakage current of this type of tantalum capacitor.

These tantalum capacitors have a higher capacitance density than their aluminium electrolytic counterparts. They can often operate at temperatures up to about 120C and therefore they are often used in equipment used in extreme conditions. For any other Tantalum Capacitors, Please go to website www.suntan.com.hk. You may find your interested in products here.

Ceramic capacitors are available now in three main types although other styles are available:

• leaded disc ceramic capacitors for through hole mounting which are resin coated
• multilayer surface mount chip ceramic capacitors
• Specialist microwave bare leadless disc ceramic capacitors that are designed to sit in a slot in the PCB and are soldered in place

Although it is possible to obtain other types of ceramic capacitor, these are the main types that can be found today. Of these the surface mount variety is used in the greatest quantities by far because of the manufacturing methods used these days for electronic equipment.