Do you know what a capacitor is? I believe that many people know and have seen, capacitors bring us a lot of convenience, able to store electrical energy, such as rechargeable batteries, there are also many kinds of capacitors, the following we will talk about what is a pulse capacitor, I hope it will help you.
These are polypropylene film capacitors. They are used in power conversion applications that need stable low dissipation factors to deal with ripple currents. These capacitors can be used to store energy in devices like inrush current generators, impulse voltage generators, or oscillation circuits for testing circuit breakers.
Two conductors close to each other, sandwiched between a layer of non-conductive insulating medium, it constitutes a capacitor. When a voltage is added between the two pole plates of a capacitor, the capacitor stores an electric charge. The capacitance of a capacitor is numerically equal to the ratio of the charge on a conducting pole plate to the voltage between the two plates. The basic unit of capacitance is the farad (F). The letter C is usually used in circuit diagrams to denote a capacitive element.
Capacitors play an important role in tuning, bypassing, coupling, filtering, and other circuits. It is used in the tuning circuit of transistor radio, and in the coupling circuit and bypass circuit of color TV.
With the rapid change of electronic information technology, the replacement of digital electronic products is becoming faster and faster, and the production and sales of consumer electronic products, mainly flat-panel TVs (LCD and PDP), notebook computers, digital cameras, etc., continue to grow, driving the growth of the capacitor industry.
What is the difference between high-voltage pulse capacitors and ordinary capacitors?
High-voltage pulse capacitors are made of two types of material: one is film type and the other is ceramic type. Ceramic has high voltage characteristics compared to film. The advantage of film capacitors is that their capacity is higher than that of ceramic capacitors.
The commonly used pulse ceramic capacitor is PC ceramic. These ceramic capacitors with a dielectric constant of 400 can operate from -55 degrees to +125 degrees. The temperature variation rate is less than 5%. It has superb voltage characteristics and pulse characteristics. The current optoelectronic military application equipment and electromagnetic pulse military application equipment mostly use PC material. Its pulse length is up to 1 million times or more.
Of course, there are also test level pulse capacitors. Many research units choose N4700 ceramic material as pulse capacitor. This material can also meet the needs of users, but if a large number of equipment, it is not enough to use the length of time. This product is used in the capacitor industry for between 3000 and 50,000 pulses. The dielectric constant of N4700 is between 1800 and 2000. The temperature range is from -25 degrees to +85 degrees with a temperature variation of about 20 percent. Therefore, in the field of ceramic capacitors, PC pulse dielectric is the true pulse capacitor.
What are the advantages of PC pulse capacitors ?
1. Pulse voltage: PC pulse capacitor has high voltage withstanding ability, which is the pulse high voltage withstanding ability, and other capacitors cannot be compared. Generally, a 50KV pulse capacitor can withstand up to 80KV pulse voltage. This is also rare in the field of high voltage ceramic capacitors;
2. High and low temperature characteristics: PC capacitors can be used in colder environments, such as minus 50 degrees, or in high temperature environments, such as high temperature 125 degrees;
3.Long pulse life: PC capacitors have high reliability and work for a long time within the rated voltage, and its pulse life is more than 1 million times.
What’s the function of Pulse capacitor?
Due to the high reliability of PC pulse capacitor, this kind of pulse capacitor can be used in most high-tech military equipment. For example, electromagnetic guns, electronic interference, radar equipment, communication transmission, etc. There are also good applications in some civil markets, such as laser cutting and other mechanical fields.
The above is the knowledge about pulse capacitor, I believe that the small partners will understand it very well after reading it, the above has its advantages as well as functions, the small partners will use it in the future, wish you to buy good pulse capacitor.
Pulse Grade Capacitors / Energy Discharge Capacitors
API Capacitors is the leading UK designer and manufacturer of advanced custom built high voltage capacitors for DC, Pulsed, and Specialist systems. We have supplied companies all over the world for many years in applications for transportation, defense, medical, research and industrial.
We look forward to working with new customers to satisfying your power capacitor requirements.
API’s technology offers an extensive solutions portfolio which includes extended foil and metallised film electrode and all types of polymer film and paper dielectric designs. These components are either vacuum impregnated, with variety of dielectric fluids, or dry.
A wide range of packaging options are available in either polypropylene welded, welded metal or drawn cases.
Metallized film as a dielectric in high pulse capacitors
Metallized polypropylene film is the dielectric most often used in capacitors designed for high powered lasers. Polypropylene film is a low loss dielectric with a high dielectric strength. Low dielectric loss is essential for high repetition rate capacitors because substantial heat can be generated at high RMS currents.
The electrodes are vapor deposited onto a thin film of polypropylene dielectric material. This dielectric configuration is able to handle high reversals and high peak current.
The capacitor itself is designed so that the current path can withstand both the high amperage and the mechanical shock of the discharge. A low inductance design is also critical as inductance increases the pulse duration.
But the most important feature to any operator of a production facility is the way that such a capacitor fails.
The metallized film possesses self-healing characteristics that provides a “soft” failure mode; with controlled self healing the total capacitance of the device is effectively divided into several million “small capacitances”. The weak points in the dielectric are isolated by the self-healing mechanism, and the device continues to work, so that the primary mode of failure for a metallized film capacitor is a gradual reduction in capacitance, and not a short circuit.
This has the important advantage of allowing equipment operators to choose when to replace capacitors by defining an end-of-life consistent with the equipment requirements. This reduces operating costs and mitigates the expense of taking the equipment off-line in the event of a catastrophic failure.
Leading manufacturers Aerovox and AVX specify metallized polypropylene for their ranges of pulse grade capacitors.
