Promise and non-inductive capacitance analysis

Capacitance is one of the most widely used electronic components in electronic devices. It is widely used in blocking, coupling, bypassing, filtering, tuning loops, energy conversion, control circuits and so on.

Frequency characteristics of the capacitor: As the frequency increases, the capacitance of the capacitor generally decreases.

Model name of the capacitor: (according to GB2470-81)

Part 1: Name the product with a letter C

Part 2: The media material of the product is indicated by letters:

A. Tantalum electrolysis

B. Non-polar film such as polypropylene

C. High frequency ceramic

D. Aluminum electrolysis

E. Other materials electrolysis

G. Alloy electrolysis

H. Paper film composite

I. Glass uranium

J. Metallized paper

L. Polar polyester film such as L polyester

N. Niobium electrolysis

O. Glass film

Q. Paint film

S, T. Low frequency ceramic

V, X. Mica paper

Y. Mica

Z. Paper

Note: When B is used to indicate other capacitors other than polystyrene, add a letter after B to separate the specific materials. When L is used for other film capacitors other than polyester, the method is the same.

Insulation resistance of the capacitor: DC voltage is applied to the capacitor and a leakage current is generated. The ratio between the two is called the insulation resistance. When the capacitance is small, it depends mainly on the surface state of the capacitor. When the capacity is > 0.1uf, it depends mainly on the medium. Performance.

The time constant of the capacitor: a time constant is introduced for proper evaluation of the insulation of the bulk capacitor, which is equal to the product of the insulation resistance of the capacitor and the capacity.

Capacitor loss factor: The energy consumed by a capacitor due to heat generated by an electric field is called loss. All types of capacitors specify their allowable values for loss in a certain frequency range. The loss of the capacitor is mainly caused by dielectric loss, conductance loss and resistance of all metal parts of the capacitor.

Under the action of DC electric field, the loss of the capacitor exists in the form of leakage conduction loss, which is generally small. Under the action of the alternating electric field, the loss of the capacitor is not only related to the leakage conduction, but also related to the periodic polarization establishment process.

Film capacitor:

The currently widely produced plastic film capacitors are polystyrene, polyethylene, polypropylene, polytetrafluoroethylene, polyester (polyester), polycarbonate, composite film and the like.

1. CL21/CBB21 metallized film capacitor (CL21-B/CBB21-B metallized film cassette type), using metallized polyester/polypropylene film as medium/electrode using non-inductive winding method, epoxy resin encapsulation It has the characteristics of excellent electrical performance, good reliability, high temperature resistance, wide capacity range, small volume, good self-healing and long life. It is mainly used in TV sets, computer monitors, energy-saving lamps, ballasts, communication equipment, Computer network equipment, electronic toys and other DC and VHF level signals are separated by DC, bypass and coupling / high frequency, AC, pulse, and coupling circuits for filtering, frequency modulation, DC blocking and time control.

2. CBB22 (MKP91) Metallized polypropylene film DC capacitor. The metallized polypropylene film is used as the medium and the electrode, and the unidirectional extraction is encapsulated by the flame-retardant insulating material, and the electrical property is excellent, the reliability is good, the loss is small, and the self-healing property is good. Uses: This product is widely used in instruments, meters, televisions, radios and household appliances for DC pulsation, pulse and AC will be used, especially for various types of energy-saving lamps and electronic rectifiers.

3. Features and uses of CBB91 metallized polypropylene capacitors: Insulation tape wrapping, epoxy resin potting, axial extraction. It has high insulation, low loss, good frequency characteristics and low equivalent series resistance. It is also suitable for audio crossovers, power amplifiers, and post-compensation circuits. It is also suitable for DC AC and pulse circuits in electronic equipment.

4. CL20 (MKT83) metallized polyester film flat axial capacitor (metallized polyester capacitor). Features: Metalized polyester film as medium and electrode, sealed with flame retardant tape and sealed with epoxy resin, with excellent electrical properties, good reliability, high temperature resistance, small volume, large capacity and good self-healing performance. Uses: This product is suitable for AC and DC circuits of instruments, meters and household appliances. Widely used in audio system crossover circuits.

5. CL20/CBB20 axial metallized film capacitor non-inductive structure, with excellent electrical performance, good reliability, high temperature resistance, small volume, large capacity, low frequency loss, strong overcurrent capability, suitable for high current, insulation High resistance, good self-healing, long life and stable temperature characteristics. It is widely used in AC and DC lines of instruments, instruments and household appliances, AC, large pulse circuits such as frequency conversion and frequency division, especially for high fidelity audio divider circuits. .

6. CL19 (MKT82) Metallized polyester film round axial capacitor. Features: Metalized polyester film as medium and electrode, sealed with flame retardant tape and sealed with epoxy resin, with excellent electrical properties, good reliability, high temperature resistance, small volume, large capacity and good self-healing performance. Uses: This product is suitable for AC and DC circuits of instruments, meters and household appliances. Widely used in audio system crossover circuits.

7. CBBX2 (MPX MKP41) Metallized polypropylene film anti-interference capacitor. The metalized zinc-aluminum polypropylene film is used as the medium and the electrode, and is sealed with a high-temperature resistant flame-retardant plastic shell and epoxy resin, and has a unidirectional lead-out structure. The product has high resistance to external electrical interference, high reliability, low loss and good performance. Self-healing properties have better safety protection. This product is widely used in color TVs, power tools, wireless connectors, cross-power lines, electromagnetic interference filters, power switches and high-power electronic rectifiers.

8. CBB13 type non-inductive capacitor. Application: Energy-saving lamps, ballasts, color TVs and electronic machines, electronic instruments, high-frequency, DC, AC and high-current pulsation circuits.

9. CL233X ultra-small capacitor (correction capacitor) uses imported ultra-small metallized polyester film as medium/electrode adopts non-inductive winding method, mainly suitable for TV, computer monitor, energy-saving lamp, ballast, program-controlled switch, Computer network equipment, VCD/DVD, precision electronic instrumentation and other DC and VHF-level signal circuits, bypass circuits, DC, coupling, filtering, etc. Withstand voltage: 50/63V series, 100V series. Capacity: 103-105.

10. CL21S ultra-small metallized polyester film correction capacitor uses imported ultra-small metallized polyester film as medium/electrode adopts non-inductive winding method, CP wire welding leads, powder epoxy resin encapsulation, with small volume Light weight, wide capacity range, high precision, large specific volume and good self-healing, long service life, mainly suitable for TV sets, computer monitors, energy-saving lamps, ballasts, program-controlled switches, computer network equipment, VCD/DVD, precision electronic instrumentation and other DC and VHF-level signal circuits, bypass circuits, DC, coupling, filtering, etc.

Ceramic dielectric capacitor:

Ceramic dielectric capacitors can be divided into low voltage, low power and high voltage and high power. In low voltage and low power, they can be divided into type I (CC type) and type II (type CT).

Type I (CC type) is characterized by small size, low loss, high capacitance to frequency and temperature stability, and is often used in high frequency circuits.

Type II (CT type) is characterized by small size, large loss, capacitance to temperature frequency and stability, and is often used in low frequency circuits.

1. High-frequency wafer ceramic capacitor (CC): capacitance: 1--6800p; rated voltage: 63--500V; main features: low frequency loss, good stability. Application: high-frequency circuit. Low frequency ceramic capacitor (CT). Capacitance: 10p - 4.7u. Rated voltage: 50V--100V. Main features: small size, low price, large loss and poor stability. Application: low frequency circuit that is not required

CC1 type 1 ceramic capacitor. Uses: CCI type 1 ceramic capacitors have high Q value and stable capacity. Used in resonant circuits and circuits that need to compensate for temperature effects. 63-500V.

CS1 type 3 ceramic capacitor. Uses: Used as ultra-high frequency, wide-band bypass capacitors and coupling capacitors or in circuits with low loss tangent and low insulation resistance. 25V-50V

CT71 type 2 AC ceramic capacitor. Uses: All kinds of electronic and electrical equipment, used for antenna coupling, switching circuits and crossover power lines. 250Vac

CT81 type 2 high voltage ceramic capacitor. Uses: Suitable for 1~3kV DC high voltage bypass and coupling circuit. The buffer circuit of the switching power supply.

2. Features of monolithic (multilayer ceramic) capacitors: large capacitance, small size, high reliability, stable capacitance, high temperature and moisture resistance. Applications: Widely used in electronic precision instruments. Various small electronic devices are used for resonance, coupling, filtering, and bypassing. Capacity range: 0.5PF--1UF. Withstand voltage: twice the rated voltage. Monoliths are also called multi-layer ceramic capacitors. They are divided into two types. Type 1 performance is quite good, but the capacity is small, generally less than 0. 2U, and the other type is type II. The capacity is large, but the performance is average. The biggest disadvantage of monolithic capacitors is the high temperature coefficient, and the stability of the oscillator is unbearable. In terms of temperature drift: monolith is positive temperature enthalpy +130 or so, CBB is negative temperature coefficient -230, parallel use with appropriate proportions, can make the temperature drift to a small.

Mica capacitor:

Mica capacitors are one of the high-performance capacitors with excellent performance and are widely used in applications where the stability and reliability of capacitors are high.

Mica Capacitance (CY): Capacitance: 10p - 0.1u. Rated voltage: 100V--7kV. Main features: high stability, high reliability, and small temperature coefficient. Applications: High frequency oscillations, pulses and other circuits that require higher levels.

Paper capacitor:

Paper capacitors are widely used because of their large ratio of capacitance, wide capacitance range, high operating voltage and low cost. The disadvantages are poor stability and high loss. They can only be used in low frequency or DC circuits. They have been replaced by synthetic membrane capacitors. There is also a place in the high-voltage paper capacitor.

1. CZ52 capacity: 0.1-0.25uf rated working voltage: 110-250v. Insulation performance: 0.1uf is 10000monh 0.25uf is 8000mohm. Loss tangent: (under normal climatic conditions) <0.01 2. Metallized paper capacitor: his electrode is formed by depositing a metal film on the capacitor paper by vacuum evaporation, so the volume is much smaller than the paper capacitor. . His main feature is self-healing. When the medium is partially broken down, its electrical properties can be immediately restored to the state before the breakdown. Although metalized paper dielectric capacitors overcome some of the shortcomings of paper dielectric capacitance, they still cannot leave the paper, their chemical stability is poor, and the loss increases sharply with increasing frequency, so it is not suitable for high frequency circuits.

2. CJ10 capacity: 0.01-1uf rated working voltage: 160-400v. Loss tangent: (under normal climatic conditions) <0.015.

Electrolytic capacitor:

CD71 non-polar aluminum electrolytic capacitor. This product has the characteristics of small volume, large capacity, low loss, no polarity and high temperature resistance. This product is suitable for polarity reversal or polarity switching circuits of instruments and electronic equipment, especially suitable for audio crossover networks.