2011-3-16 2:26:9
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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
2011-3-15 2:27:44
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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
2011-3-14 12:13:8
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Мы занимаемся производством пленочных конденсаторов с 1980 года. Мы производим высококачественную продукцию и продаем по хорошим, конкурентоспособным ценам. Подскажите, пожалуйста, есть ли у вас запрос на пленочные конденсаторы?
Конденсаторы X2 (jb JFO X2 series)
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Конденсаторы PPS (jb JFP)
ПЛЕНОЧНЫЕ МЕТАЛЛИЗИРОВАННЫЕ КОНДЕНСАТОРЫ К73-17 (CL21) (jb JFB, JFE)
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2011-3-11 12:1:55
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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.
2011-3-10 11:55:49
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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
2011-3-8 15:36:54
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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
2011-3-2 10:41:58
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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.
2011-2-26 16:40:12
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To use this table, just read across. For example, 1uF is same 1,000nF or 1,000,000pF.
uF/ MFD | nF | pF/ MMFD | | uF/ MFD | nF | pF/ MMFD |
1uF / MFD | 1000nF | 1000000pF(MMFD) | | 0.001uF / MFD | 1nF | 1000pF(MMFD) |
0.82uF / MFD | 820nF | 820000pF (MMFD) | | 0.00082uF / MFD | 0.82nF | 820pF (MMFD) |
0.8uF / MFD | 800nF | 800000pF (MMFD) | | 0.0008uF / MFD | 0.8nF | 800pF (MMFD) |
0.7uF / MFD | 700nF | 700000pF (MMFD) | | 0.0007uF / MFD | 0.7nF | 700pF (MMFD) |
0.68uF / MFD | 680nF | 680000pF (MMFD) | | 0.00068uF / MFD | 0.68nF | 680pF (MMFD) |
0.6uF / MFD | 600nF | 600000pF (MMFD) | | 0.0006uF / MFD | 0.6nF | 600pF (MMFD) |
0.56uF / MFD | 560nF | 560000pF (MMFD) | | 0.00056uF / MFD | 0.56nF | 560pF (MMFD) |
0.5uF / MFD | 500nF | 500000pF (MMFD) | | 0.0005uF / MFD | 0.5nF | 500pF (MMFD) |
0.47uF / MFD | 470nF | 470000pF (MMFD) | | 0.00047uF / MFD | 0.47nF | 470pF (MMFD) |
0.4uF / MFD | 400nF | 400000pF (MMFD) | | 0.0004uF / MFD | 0.4nF | 400pF (MMFD) |
0.39uF / MFD | 390nF | 390000pF (MMFD) | | 0.00039uF / MFD | 0.39nF | 390pF (MMFD) |
0.33uF / MFD | 330nF | 330000pF (MMFD) | | 0.00033uF / MFD | 0.33nF | 330pF (MMFD) |
0.3uF / MFD | 300nF | 300000pF (MMFD) | | 0.0003uF / MFD | 0.3nF | 300pF (MMFD) |
0.27uF / MFD | 270nF | 270000pF (MMFD) | | 0.00027uF / MFD | 0.27nF | 270pF (MMFD) |
0.25uF / MFD | 250nF | 250000pF (MMFD) | | 0.00025uF / MFD | 0.25nF | 250pF (MMFD) |
0.22uF / MFD | 220nF | 220000pF (MMFD) | | 0.00022uF / MFD | 0.22nF | 220pF (MMFD) |
0.2uF / MFD | 200nF | 200000pF (MMFD) | | 0.0002uF / MFD | 0.2nF | 200pF (MMFD) |
0.18uF / MFD | 180nF | 180000pF (MMFD) | | 0.00018uF / MFD | 0.18nF | 180pF (MMFD) |
0.15uF / MFD | 150nF | 150000pF (MMFD) | | 0.00015uF / MFD | 0.15nF | 150pF (MMFD) |
0.12uF / MFD | 120nF | 120000pF (MMFD) | | 0.00012uF / MFD | 0.12nF | 120pF (MMFD) |
0.1uF / MFD | 100nF | 100000pF (MMFD) | | 0.0001uF / MFD | 0.1nF | 100pF (MMFD) |
0.082uF / MFD | 82nF | 82000pF (MMFD) | | 0.000082uF / MFD | 0.082nF | 82pF (MMFD) |
0.08uF / MFD | 80nF | 80000pF (MMFD) | | 0.00008uF / MFD | 0.08nF | 80pF (MMFD) |
0.07uF / MFD | 70nF | 70000pF (MMFD) | | 0.00007uF / MFD | 0.07nF | 70pF (MMFD) |
0.068uF / MFD | 68nF | 68000pF (MMFD) | | 0.000068uF / MFD | 0.068nF | 68pF (MMFD) |
0.06uF / MFD | 60nF | 60000pF (MMFD) | | 0.00006uF / MFD | 0.06nF | 60pF (MMFD) |
0.056uF / MFD | 56nF | 56000pF (MMFD) | | 0.000056uF / MFD | 0.056nF | 56pF (MMFD) |
0.05uF / MFD | 50nF | 50000pF (MMFD) | | 0.00005uF / MFD | 0.05nF | 50pF (MMFD) |
0.047uF / MFD | 47nF | 47000pF (MMFD) | | 0.000047uF / MFD | 0.047nF | 47pF (MMFD) |
0.04uF / MFD | 40nF | 40000pF (MMFD) | | 0.00004uF / MFD | 0.04nF | 40pF (MMFD) |
0.039uF / MFD | 39nF | 39000pF (MMFD) | | 0.000039uF / MFD | 0.039nF | 39pF (MMFD) |
0.033uF / MFD | 33nF | 33000pF (MMFD) | | 0.000033uF / MFD | 0.033nF | 33pF (MMFD) |
0.03uF / MFD | 30nF | 30000pF (MMFD) | | 0.00003uF / MFD | 0.03nF | 30pF (MMFD) |
0.027uF / MFD | 27nF | 27000pF (MMFD) | | 0.000027uF / MFD | 0.027nF | 27pF (MMFD) |
0.025uF / MFD | 25nF | 25000pF (MMFD) | | 0.000025uF / MFD | 0.025nF | 25pF (MMFD) |
0.022uF / MFD | 22nF | 22000pF (MMFD) | | 0.000022uF / MFD | 0.022nF | 22pF (MMFD) |
0.02uF / MFD | 20nF | 20000pF (MMFD) | | 0.00002uF / MFD | 0.02nF | 20pF (MMFD) |
0.018uF / MFD | 18nF | 18000pF (MMFD) | | 0.000018uF / MFD | 0.018nF | 18pF (MMFD) |
0.015uF / MFD | 15nF | 15000pF (MMFD) | | 0.000015uF / MFD | 0.015nF | 15pF (MMFD) |
0.012uF / MFD | 12nF | 12000pF (MMFD) | | 0.000012uF / MFD | 0.012nF | 12pF (MMFD) |
0.01uF / MFD | 10nF | 10000pF (MMFD) | | 0.00001uF / MFD | 0.01nF | 10pF (MMFD) |
0.0082uF / MFD | 8.2nF | 8200pF (MMFD) | | 0.0000082uF / MFD | 0.0082nF | 8.2pF (MMFD) |
0.008uF / MFD | 8nF | 8000pF (MMFD) | | 0.000008uF / MFD | 0.008nF | 8pF (MMFD) |
0.007uF / MFD | 7nF | 7000pF (MMFD) | | 0.000007uF / MFD | 0.007nF | 7pF (MMFD) |
0.0068uF / MFD | 6.8nF | 6800pF (MMFD) | | 0.0000068uF / MFD | 0.0068nF | 6.8pF (MMFD) |
0.006uF / MFD | 6nF | 6000pF (MMFD) | | 0.000006uF / MFD | 0.006nF | 6pF (MMFD) |
0.0056uF / MFD | 5.6nF | 5600pF (MMFD) | | 0.0000056uF / MFD | 0.0056nF | 5.6pF (MMFD) |
0.005uF / MFD | 5nF | 5000pF (MMFD) | | 0.000005uF / MFD | 0.005nF | 5pF (MMFD) |
0.0047uF / MFD | 4.7nF | 4700pF (MMFD) | | 0.0000047uF / MFD | 0.0047nF | 4.7pF (MMFD) |
0.004uF / MFD | 4nF | 4000pF (MMFD) | | 0.000004uF / MFD | 0.004nF | 4pF (MMFD) |
0.0039uF / MFD | 3.9nF | 3900pF (MMFD) | | 0.0000039uF / MFD | 0.0039nF | 3.9pF (MMFD) |
0.0033uF / MFD | 3.3nF | 3300pF (MMFD) | | 0.0000033uF / MFD | 0.0033nF | 3.3pF (MMFD) |
0.003uF / MFD | 3nF | 3000pF (MMFD) | | 0.000003uF / MFD | 0.003nF | 3pF (MMFD) |
0.0027uF / MFD | 2.7nF | 2700pF (MMFD) | | 0.0000027uF / MFD | 0.0027nF | 2.7pF (MMFD) |
0.0025uF / MFD | 2.5nF | 2500pF (MMFD) | | 0.0000025uF / MFD | 0.0025nF | 2.5pF (MMFD) |
0.0022uF / MFD | 2.2nF | 2200pF (MMFD) | | 0.0000022uF / MFD | 0.0022nF | 2.2pF (MMFD) |
0.002uF / MFD | 2nF | 2000pF (MMFD) | | 0.000002uF / MFD | 0.002nF | 2pF (MMFD) |
0.0018uF / MFD | 1.8nF | 1800pF (MMFD) | | 0.0000018uF / MFD | 0.0018nF | 1.8pF (MMFD) |
0.0015uF / MFD | 1.5nF | 1500pF (MMFD) | | 0.0000015uF / MFD | 0.0015nF | 1.5pF (MMFD) |
0.0012uF / MFD | 1.2nF | 1200pF (MMFD) | | 0.0000012uF / MFD | 0.0012nF | 1.2pF (MMFD) |
0.001uF / MFD | 1nF | 1000pF (MMFD) | …… | 0.000001uF / MFD | 0.001nF | 1pF (MMFD) |
2011-2-25 21:10:10
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The unit of capacitance is the Farad (abbreviated to F) named after the British physicist Michael Faraday and is defined as a capacitor has the capacitance of One Farad when a charge of One Coulomb is stored on the plates by a voltage of One volt. Capacitance, C is always positive and has no negative units. However, the Farad is a very large unit of measurement to use on its own so sub-multiples of the Farad are generally used such as micro-farads, nano-farads and pico-farads, for example.
Microfarad (μF) 1μF = 1/1,000,000 = 0.000001 = 10-6 F
Nanofarad (nF) 1nF = 1/1,000,000,000 = 0.000000001 = 10-9 F
Picofarad (pF) 1pF = 1/1,000,000,000,000 = 0.000000000001 = 10-12 F
The capacitance of a parallel plate capacitor is proportional to the area, A of the plates and inversely proportional to their distance or separation, d (i.e. the dielectric thickness) giving us a value for capacitance of C = k( A/d ) where in a vacuum the value of the constant k is 8.84 x 10-12 F/m or 1/4.π.9 x 109, which is the permittivity of free space. Generally, the conductive plates of a capacitor are separated by air or some kind of insulating material or gel rather than the vacuum of free space.
2011-2-23 7:4:44
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The parallel plate capacitor is the simplest form of capacitor and its capacitance value is fixed by the surface area of the conductive plates and the distance or separation between them. Altering any two of these values alters the the value of its capacitance and this forms the basis of operation of the variable capacitors. Also, because capacitors store the energy of the electrons in the form of an electrical charge on the plates the larger the plates and/or smaller their separation the greater will be the charge that the capacitor holds for any given voltage across its plates. In other words, larger plates, smaller distance, more capacitance.
By applying a voltage to a capacitor and measuring the charge on the plates, the ratio of the charge Q to the voltage V will give the capacitance value of the capacitor and is therefore given as: C = Q/V this equation can also be re-arranged to give the more familiar formula for the quantity of charge on the plates as: Q = C x V
Although we have said that the charge is stored on the plates of a capacitor, it is more correct to say that the energy within the charge is stored in an "electrostatic field" between the two plates. When an electric current flows into the capacitor, charging it up, the electrostatic field becomes more stronger as it stores more energy. Likewise, as the current flows out of the capacitor, discharging it, the potential difference between the two plates decreases and the electrostatic field decreases as the energy moves out of the plates.
The property of a capacitor to store charge on its plates in the form of an electrostatic field is called the Capacitance of the capacitor. Not only that, but capacitance is also the property of a capacitor which resists the change of voltage across it.