Suntan Polystyrene Film Capacitors

June 27, 2011 Views
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In these devices, polystyrene film is used as the dielectric. This type of capacitor is not for use in high frequency circuits, because they are constructed like a coil inside. They are used well in filter circuits or timing circuits which run at several hundred KHz or less.

The component shown on the left has a red color due to the copper leaf used for the electrode. The silver color is due to the use of aluminum foil as the electrode.

  • The device on the left has a height of 10 mm, is 5 mm thick, and is rated 100pF.
  • The device in the middle has a height of 10 mm, 5.7 mm thickness, and is rated 1000pF.
  • The device on the right has a height of 24 mm, is 10 mm thick, and is rated 10000pF.
  • These devices have no polarity.

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Suntan History of the Capacitor

June 24, 2011 Views
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The invention of the capacitor varies somewhat depending on who you ask. There are records that indicate a German scientist named Ewald Georg von Kleist invented the capacitor in November 1745. Several months later Pieter van Musschenbroek, a Dutch professor at the University of Leyden came up with a very similar device in the form of the Leyden jar, which is typically credited as the first capacitor. Since Kleist didn't have detailed records and notes, nor the notoriety of his Dutch counterpart, he's often overlooked as a contributor to the capacitor's evolution. However, over the years, both have been given equal credit as it was established that their research was independent of each other and merely a scientific coincidence.

The Leyden jar was a very simple device. It consisted of a glass jar, half filled with water and lined inside and out with metal foil. The glass acted as the dielectric, although it was thought for a time that water was the key ingredient. There was usually a metal wire or chain driven through a cork in the top of the jar. The chain was then hooked to something that would deliver a charge, most likely a hand-cranked static generator. Once delivered, the jar would hold two equal but opposite charges in equilibrium until they were connected with a wire, producing a slight spark or shock.

Benjamin Franklin worked with the Leyden jar in his experiments with electricity and soon found that a flat piece of glass worked as well as the jar model, prompting him to develop the flat capacitor, or Franklin square. Years later, English chemist Michael Faraday would pioneer the first practical applications for the capacitor in trying to store unused electrons from his experiments. This led to the first usable capacitor, made from large oil barrels. Faraday's progress with capacitors is what eventually enabled us to deliver electric power over great distances. As a result of Faraday's achievements in the field of electricity, the unit of measurement for capacitors, or capacitance, became known as the farad.

For more information on capacitors and related topics, check out the links on the next page.

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Suntan Electrolytic Capacitors

June 22, 2011 Views
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Electrolytic capacitors are polarised and they must be connected the correct way round, at least one of their leads will be marked + or -. They are not damaged by heat when soldering.

There are two designs of electrolytic capacitors; axial where the leads are attached to each end (220µF in picture) and radial where both leads are at the same end (10µF in picture). Radial capacitors tend to be a little smaller and they stand upright on the circuit board.

It is easy to find the value of electrolytic capacitors because they are clearly printed with their capacitance and voltage rating. The voltage rating can be quite low (6V for example) and it should always be checked when selecting an electrolytic capacitor. If the project parts list does not specify a voltage, choose a capacitor with a rating which is greater than the project's power supply voltage. 25V is a sensible minimum for most battery circuits.

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Suntan Trimmer capacitors

June 20, 2011 Views
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Trimmer capacitors (trimmers) are miniature variable capacitors. They are designed to be mounted directly onto the circuit board and adjusted only when the circuit is built.

A small screwdriver or similar tool is required to adjust trimmers. The process of adjusting them requires patience because the presence of your hand and the tool will slightly change the capacitance of the circuit in the region of the trimmer!

Trimmer capacitors are only available with very small capacitances, normally less than 100pF. It is impossible to reduce their capacitance to zero, so they are usually specified by their minimum and maximum values, for example 2-10pF.

Trimmers are the capacitor equivalent of presets which are miniature variable resistors.

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Suntan Multi-turn Trimming Potentiometers

June 15, 2011 Views
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Trimming potentiometers perform a variety of circuit adjustments in all types of electronic equipment. The variety of physical configurations available and the ability to withstand today's manufacturing environment offers the designer flexibility in selecting the best trimmer for the application. Around the world, trimmers are used in virtually every electronic market.

Typical applications include measuring linear distance, angles or rotations in production equipment, industrial test and measurement equipment, and medical equipment.

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Suntan tell you What is a Varistor?

June 10, 2011 Views
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A varistor is a type of resistor with a significantly non-ohmic current-voltage characteristic. The name is a portmanteau of variable resistor*, which is misleading since it is not continuously user-variable like a potentiometer or rheostat, and is not a resistor but in fact a capacitor. Varistors are often used to protect circuits against excessive voltage by acting as a spark gap.

The most common type of varistor is the metal oxide varistor, or MOV. This contains a mass of zinc oxide grains, in a matrix of other metal oxides, sandwiched between two metal plates (the electrodes). The boundary between each grain and its neighbour forms a diode junction, which allows current to flow in only one direction. The mass of randomly oriented grains is electrically equivalent to a network of back-to-back diode pairs, each pair in parallel with many other pairs. When a small or moderate voltage is applied across the electrodes, only a tiny current flows, causes by reverse leakage through the diode junctions. When a large voltage is applied, the diode junctions break down because of the avalanche effect, and a large current flows. The result of this behaviour is a highly nonlinear current-voltage characteristic, in which the MOV has a high resistance at low voltages and a low resistance at high voltages.

If the size of the transient pulse (often measured in joules) is too high, the device may melt, or otherwise be damaged. For example, a nearby lightning strike may permanently damage a varistor.

Important parameters for varistors are response time (how long it takes the varistor to break down), maximum current and a well-defined breakdown voltage. When used in communications lines (such as phone lines used for modems), high capacitance is undesirable since it absorbs high frequency signals, thereby reducing the available bandwidth of the line being protected.

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Suntan Strong Promotion - Interference Suppression Film X2 Capacitor TS08S

June 8, 2011 Views
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Suntan has specially developed a new series of X2 capacitors TS08S series with metalized polypropylene films for interference suppression. These capacitors are designed for voltages of 275VAC, specified for temperatures from -40 to +100 °C, capacitance range extended from 1 nF to 2.2 µF, or customized as requested. This new X2 series provide interference suppression with CE & TUV and UL safety approvals. Their Typical applications include power supplies of all types, lamp ballasts and EMC filters.

Currently TS08S is Suntan strong promoting product, with our best support always. Welcome to send new inquiries from our old and new customers!

Further information on the products presented here will be found at http://www.suntan.com.hk/pdf/Plastic-Film-Capacitors/TS08S.pdf

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The Shortest Lead time on Stacked Film Capacitor & Tantalum Capacitor

June 6, 2011 Views
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Now Suntan can support shorter lead time than other manufacturers on below series.

Mini Box Metalized Polyester Film Capacitor, only 5~6 weeks. Hot Offer Now!

General TS05 series: http://www.suntan.com.hk/pdf/Plastic-Film-Capacitors/TS05.pdf

Stacked TS05S series: http://www.suntan.com.hk/pdf/Plastic-Film-Capacitors/TS05S.pdf

Dipped Tantalum Capacitor TS19 series: http://www.suntan.com.hk/pdf/Tantalum-Capacitors/TS19.pdf

Besides, we now have strong support on our trimming potentiometer.

Trimming Potentiometer TSR series: http://www.suntan.com.hk/Trimming-Potentiometers/

If you have any requirement for these, please do check details with our experienced sales!

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