jbcapacitors blog

Film capacitors mainly used in electronics, home appliance, communication, electrified railway, HEV(Hybrid Electric Vehicle), wind power generation, solar electrical energy generation etc..

As the demand of film capacitors for frequency home appliance is bigger than that of common home appliance, its advantages of energy conservation and environmental protection are more and more popular, future market is much bigger. After Japanese earthquake, frequency home appliance market much bigger than CFL, and the development potential even bigger.

With the development of technology, electronics, home appliances, communications and other industries replacement cycles are getting shorter, and film capacitors with its good electrical performance and high reliability, become the indispensable electronics components for promoting and upgrading of the above industries.With the next few years, digital, information technology, network construction and further development of countries in the power grid construction, electrification of railway construction, energy efficient lighting, hybrid cars, etc. to increase investment and consumer electronics products, upgrades, market demand for film capacitors will further show rapid growth trend

Mylar Polyester film has a lot of mechanical, di-electrical, excellent optical and physical strength and so it is been widely used in many fields. It is mainly used for the purpose of insulation and is used in electrical equipment, appliance, and membrane switch.

The features of Mylar Polyester film capacitor are as follows. It is train-and tear-resistant, dimensionally stable and has excellent electrical properties. This material has good heat-and cold-resistant properties and is resistant to common solvents. The main application of Mylar Polyester film capcitor is that it is used as intermediate and top layer insulation in transformers, chokes and relay coils. Furthermore, it is used as slot and phase insulation, as a cover slide, in electric machinery, generators, as insulating layer for magnets and in electrical equipment been used..

jb capacitors company has such product, JFA—Mylar Polyester Film Capacitor, welcome to visit website www.jbcapacitors.com for further details.

1.)Capacitors Breakdown voltage

Main article: Breakdown voltage

The breakdown voltage of the dielectric limits the power density of capacitors. For a particular dielectric, the breakdown voltage is proportional to the thickness of the dielectric.

If a manufacturer makes a new capacitor with the same dielectric as some old capacitor, but with half the thickness of the dielectric, the new capacitor has half the breakdown voltage of the old capacitor.

Because the plates are closer together, the manufacturer can put twice the parallel-plate area inside the new capacitor and still fit it in the same volume (capacitor size) as the old capacitor. Since the capacitance of a parallel-plate capacitor is given by: 

this new capacitor has 4 times the capacitance as the old capacitor.

Since the energy stored in a capacitor is given by: 

This new capacitor has the same maximum energy density as the old capacitor.

The energy density depends only on the dielectric. Making a few thick layers of dielectric (which can support a high voltage, but results in a low capacitance), or making many very thin layers of dielectric (which results in a low breakdown voltage, but a higher capacitance) has no effect on the energy density.

2.) Standard values

Before 1960 electronic components values were not standardised. The more common, but not the only, values for capacitors were 1.0, 1.5, 2.0, 3.0, 5.0, 6.0, and 8.0 as base numbers multiplied by some negative or positive power of ten. Values of 0.001 µF and above were stated in microfarads (µF, or often mF); lower values were stated in micro-microfarads (µµF, now called picofarads, pF).

In the late 1960s a standardized set of geometrically increasing preferred values was introduced. According to the number of values per decade, these were called the E3, E6, E12, etc. series

In many applications capacitors need not be specified to tight tolerance (they often need only to exceed a certain value); this is particularly true for electrolytic capacitors, which are often used for filtering and bypassing. Consequently capacitors, particularly electrolytics, often have a tolerance range of ±20% and need to be available only within E6 (or E3) series values.

 

From 2010, mini box type stacked metallized polyester film capacitors lead time became longer & Longer,  at the end of 2010, some suppliers lead time was more than 80 weeks or even allocation. Customers are desperate for these parts, seems the price is not so important then.

In order to meet many customers' needs, jb capacitors have done many efforts to improve the lead time of our JFJ series mini box 5mm MKT capacitor. Currently we offer 5-6 weeks lead time.

Short lead time can help customers win more opportunities & projects! Welcome to send your urgent inquiry & order to us. :)
JFJ-Mini box stacked metallized polyester film capacitor
Datasheet: http://www.jbcapacitors.com/pdf/JFJ-Mini-Box-Stacked-Metallized-Polyester-Film-Capacitor.pdf
Pitch size: 5mm mini size,Cross Arcotronics(Kemet) R82 series, Vishay MKT370 series, Epcos: B32529 series, etc..

Description :

1. High frequency operation.
2. High du / dt.
3. High insulation resistance.
4. Flame retardant epoxy resin (UL 94V-0).

Specification :

1. Operating temperature: -40℃~+100℃.
2. Capacitance range: 0.0022μF~1μF.
3. Capacitance tolerance: ±10% (K).
4. Rated voltage: 300V, 280V, 275V. 250V.AC
5. Dissipation factor: 0.08% max at 1KHz 20℃ 0.3% max at 10KHz 20℃.
6. Insulation resistance: 1.R≥30,000MΩ (C≤0.33μF) 1.R≥10,000MΩ (C>0.33μF)

These Metallized Polypropylene Capacitors are specifically designed for high current, high frequency applications like switching power supplies. Film capacitors offer a much higher degree of reliability and stability than other types of capacitors. Polypropylene capacitors are non-polar, they come in the all case styles, including Wrap & Fill, Epoxy Case, and Metal Hermetically Sealed.

Metallized Polypropylene capacitors have high current end terminations to handle high pulse currents as well as high RMS currents. Detailed specifications as well case sizes for our standard Axial Wrap & Fill are linked www.jbcapacitors.com For custom designs please contact our sales with your specific requirements as we specialize in custom made capacitors.

Vibration Test:

Test condition E for 720P, test condition B all others; no mechanical damage, short, open or intermittent circuit.

Moisture Resistance:

The hermetically sealed units shall be tested as outlined in the Moisture Resistance testing of section J. As a result of the test there shall be:

• No visible damage
• Max. ∆ C of ± 0.25%
• Min. IR = 33% of initial limit
• Max. DF = 0.12%

This capacitor is small, with long lifespan and good self-healing ability. It is widely used as the start-up and running capacitor, especially for micro water pumps, cleaning machines, washing machines, and single-phase water pump motors.

Features:

jb film capacitors offers a full voltage range, from 63VDC to 2000VDC; our high voltage film capacitors include JFP (epoxy coating dipped type) and JFQ (box type) two series. JFA mylar polyester film capacitors, 1000V, 1200V is very popular. Also AC voltage and DC voltage both available, AC type film capacitors include JFC (AC metallized polyester film capacitors), JFN & JFO X2 class and JFT X1 class......

Tolerance range: ±1%, ±2%, ±2.5%, ±5%, ±10%

Temperature range: normally film capacitors temperature range is -40'C to 85'C, for some series we can provide a wide temperature range up to 125'C.

jb film capacitors technology available: winding technology and stacked technology (JFJ mini box series); single side metallized structure and double sided metallized structure (JFQ series) Safety Approvals of film capacitors: UL, TUV, CE, VDE...., X2 class, X1 class

Packaging: Ammo packaging and Bulk packaging both available, and all jb film capacitors are RoHS compliant

Film Capacitors are Non polarized, and may be used in AC or DC circuits.
Typical values range form 1000pF to 1uF for Polyerster Film, and 0.01uF to 18uF for Metallized Film capacitors. Standard Film Capacitor values change in multiples of 10, 12, 15, 18, 22, 27, 33, 39, 47, 56, 68, 82.

Normal Temperature Coefficient [TC] for Film Capacitors is +7%.

• Mylar: has a wide temperature change of 20% over -55 to +125°C. Moisture absorption is half that of paper.
  Mylar is the same as polyester. The term Mylar is a trade name.
• Polycarbonate: Out performs Mylar in all areas. Low Power factor, works best with AC. Polycarbonate has a low temperature drift (graph below), dissipation factor, and dielectric absorption. Use polyphenylene sulfide as a possible replacement.
• Polyester: Replaces paper for many applications, and smaller in size. Polyester does not have the moisture problem that paper does, but does have a worse tolerance, at 20% ~ over -55 to +125°C. May also be called PETE, or PETP. The Polyester Dielectric has an Absorption of around 0.20%.
• Polypropylene: It has negative temperature coefficient.
• Polysulfone: Has a very high operating temperature of +170°C.
• Polystyrene: Will only work to +65°C. It has a flat to negative temperature coefficient.
• Teflon: Has a very high operating temperature of +170°C.

The features of film capacitor are non-inductive construction, self-healing, high reliable and superior performance in high frequency applications. It is applied to filter and noise suppression circuit, pulse logic and timing circuit, DC blocking, by-passing and signal coupling in general communication equipment. The construction of film capacitor includes polyester film dielectric with vacuum-evaporated metal electrodes, radial leads of tinned wire are electrically welded to the contact metal layer on the ends of capacitor winding, epoxy resin coating.

Are you interested in learning more details about Film Capacitors? jb Capacitors manufactures and markets Plastic Film Capacitors, Including Mylar Polyester Film Capacitor, Metallized Polyester Film Capacitor, Box Type Met Polyester Film Capacitor, X2 Metallized Polypropylene Film Capacitor and Metallized Polypropylene Film AC Capacitor Class-X1 etc. Please refer to our website www.jbcapacitors.com for the detailed Film Capacitors.