jbcapacitors blog

In theory, the dielectric can be any nonconductive substance. However, for practical applications, specific materials are used that best suit the capacitor's function. Mica, ceramic, cellulose, porcelain, Mylar, Teflon and even air are some of the nonconductive materials used. The dielectric dictates what kind of capacitor it is and for what it is best suited. Depending on the size and type of dielectric, some capacitors are better for high frequency uses, while some are better for high voltage applications. Capacitors can be manufactured to serve any purpose, from the smallest plastic capacitor in your calculator, to an ultra capacitor that can power a commuter bus. NASA uses glass capacitors to help wake up the space shuttle's circuitry and help deploy space probes. Here are some of the various types of capacitors and how they are used.

Air - Often used in radio tuning circuits
Mylar - Most commonly used for timer circuits like clocks, alarms and counters
Glass - Good for high voltage applications
Ceramic - Used for high frequency purposes like antennas, X-ray and MRI machines
Super capacitor - Powers electric and hybrid cars

Au département d'achat ou de vente:
Comment allez-vous ?

Maintenant nous sommes foyer sur favoriser notre série de JFV ! Cette série est pour le marché d'oversea, et employé couramment en ballasts électroniques, ventilateurs, éclairage, mètre de puissance, fournisseurs de puissance….application partout dans le monde. Achetez-vous des condensateurs du film X2 ? Bienvenue pour nous envoyer l'enquête et pour vérifier nos prix. Merci.

Série de JFV--Condensateurs de film de polypropylène métallisés par X2 
Approbation de sûreté : Approbations de la CE et de TUV et d'UL.
Chaîne de capacité : 1000pF~2.2uF
Correspondance: Panasonic ECQU, Vishay MKP3382 275Vac, Wima MP3, Arcotronics R46, Pilkor PCX2 337,Epcos B81130, Evox Rifa PHE840M. 
Délai d'exécution court : environ 5~7 semaines
Datasheet: http://www.jbcapacitors.com/pdf/JFV-X2-Metallized-Polypropylene-Film-Capacitor.pdf

rated capacitance (cr)

The rated capacitance of a capacitor is the value which is indicated upon it. The capacitance is measured at 1 kHz and +23°C.

rated voltage (ur)

The rated voltage is the maximum direct voltage or the maximum RMS alternating voltage which may be applied continuously to the terminals of the capacitor at any temperature within the rated temperature range.

C = nominal value of the capacitor

L = inductance (leads, metallization, winding)

ESR = equivalent series resistance (leads, metallization, metal spraying)

IR = insulation resistance (properties of the dielectric material)

∆C = capacitance change (depending on changes in temperature, DC voltage and/or frequency)

PR = dielectric polarization resistance

Cda = dielectric absorption

Capacitors loaded with pulses with fast rise or fall times (high dU/dt) will be exposed to high current pulses. In order not to overload the internal connections the current must be limited. The current limits for a specifc type are dependent upon:

• Amplitude and form of the pulse
• Rated voltage of the capacitor
• Capacitance
• Geometrical configuration of the winding

dU/dt = UR/(R x C)

UR = Rated voltage
R = Discharge resistor
C = Rated capacitance

The reliability of a capacitor is mainly a function of:

• The construction; dielectric material and its thickness
• The manufacturing process
• The application; electrical stress and temperature

A colour code was used on polyester capacitors for many years. It is now obsolete, but of course there are many still around. The colours should be read like the resistor code, the top three colour bands giving the value in pF. Ignore the 4th band (tolerance) and 5th band (voltage rating).

For example:brown, black, orange  means 10000pF = 10nF = 0.01µF.

Note that there are no gaps between the colour bands, so 2 identical bands actually appear as a wide band.

For example:wide red, yellow   means 220nF = 0.22µF.

Capacitors in a parallel configuration each have the same applied voltage. Their capacitances add up. Charge is apportioned among them by size. Using the schematic diagram to visualize parallel plates, it is apparent that each capacitor contributes to the total surface area.

Ceq=C1+C2+……+Cn

Basically the SMD series have the same electrical characteristics as the analogous through-hole WIMA capacitors. Compared to ceramic or tantalum dielectrics WIMA SMD capacitors have a number of other outstanding qualities:

• favourable pulse rise time
• low ESR
• low dielectric absorption
• available in high voltage series
• large capacitance spectrum
• stand up to high mechanical stress
• good long-term stability

The capacitors are usable for radial manual insertion on PCB. The fixation on the board by double kinked leads prevents that the component jumps out of the PCB during transport.

The components with lead diameter of 0.6 mm are usable for being inserted in punched holes with nominal diameter of 0.8 mm and the components with lead diameter of 0.8 mm are usable for being inserted in punched holes with nominal diameter of 1.0 mm.

The pitch is specified on the top of the leads. After manufacturing, the products meet the specification. Although special care is taken to the packaging, deviations may occur due to transport.