FCN3931E394K-U Product Introduction:
Cornell Dubilier Electronics (CDE) Part Number FCN3931E394K-U(Film Capacitors), developed and manufactured by Cornell Dubilier Electronics (CDE), distributed globally by Jinftry. We distribute various electronic components from world-renowned brands and provide one-stop services, making us a trusted global electronic component distributor.
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Film capacitors are capacitors that use thin film materials as dielectric. This structure mainly consists of two layers of conductive metal foil, sandwiched with a thin film medium, which is usually made of polymer materials such as polyether esters, polypropylene, or polystyrene. The design principle is based on the storage of charges. When voltage is applied to both ends of the capacitor, positive and negative charges accumulate on two layers of metal foil, forming an electric field. Thin film capacitors are renowned for their high stability, low loss factor, and wide operating temperature range, and are particularly suitable for high-frequency circuits. In addition, due to its good self-healing ability, which can self recover after partial breakdown in the dielectric, it has a long service life and high reliability.
Application
Film capacitors are mainly used in multiple industries such as electronics, communication, automotive electronics, and medical equipment. In power electronics equipment, they are widely used in DC link filtering, power supply stabilization, and motor drive circuits to ensure smooth current and stable voltage. In audio devices such as speaker crossover networks, preamplifiers, and power amplifiers, thin film capacitors are favored for their excellent frequency response and low distortion characteristics, which help improve sound quality performance. In addition, thin film capacitors are often used in signal processing and filtering in communication systems, which can effectively remove noise in the signal and improve transmission quality. In the field of automotive electronics, thin film capacitors are used in engine management systems, airbag circuits, and in car entertainment systems to ensure circuit stability and safety. In medical equipment, such as electrocardiogram monitors and pacemakers, the high precision and stability of thin film capacitors make them key components that play an important role in monitoring and treating the health of patients.
FAQ about Film Capacitors
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1. Are film capacitors better than electrolytic capacitors?
Not necessarily
Film capacitors and electrolytic capacitors each have their own advantages and disadvantages, and the specific choice depends on the application scenario.
Advantages of film capacitors
Non-polarity: Film capacitors are non-polar, and there is no need to distinguish between positive and negative poles, avoiding the risk of capacitor explosion due to reverse connection.
Long life: Film capacitors have significantly longer life and better stability.
Wide temperature range: Film capacitors have a wide operating temperature range, generally -40℃~+105℃/110℃, suitable for various ambient temperatures.
High withstand voltage: Film capacitors can withstand overvoltages higher than 1.5 times the rated voltage in a short period of time, and have strong withstand voltage.
Low loss: Film capacitors have low loss and are suitable for high-frequency circuits, especially for occasions requiring low loss and high-frequency applications.
Advantages of electrolytic capacitors
Large capacity: Electrolytic capacitors usually have large capacitance and are suitable for occasions requiring large amounts of energy storage.
Low cost: The cost of electrolytic capacitors is relatively low, suitable for occasions with strict cost requirements.
High energy density: Electrolytic capacitors are a strong choice when cost-effective, high-capacity energy storage is required, especially when maintaining DC output voltage during power outages.
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2. Can film capacitors be used for AC?
Yes
Film capacitors can be used for AC. Film capacitors can work normally in AC circuits and have specific application scenarios and advantages.
Structure and working principle of film capacitors
Film capacitors are mainly composed of metal foil (or foil obtained by metallizing plastic) as electrode plates and plastic film as dielectric. Common plastic films include polyethylene, polypropylene, polystyrene or polycarbonate. These capacitors are usually made by winding or stacking processes to form a cylindrical structure.
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3. How do film capacitors fail?
High working environment temperature, improper selection of working current, exceeding the specified working voltage, harmonic current
The main reasons for film capacitor failure include the following:
High working environment temperature: Film capacitors can work normally in a temperature environment of -40℃~+105℃, but exceeding this range will accelerate thermal aging, resulting in a shortened service life, and even bursting in severe cases.
Improper selection of working current: The current value in the circuit should be less than the current value allowed by the film capacitor, otherwise it will cause the capacitor to heat up, and long-term use will shorten the life, and even burst in severe cases.
Exceeding the specified working voltage: Excessive voltage will cause partial discharge, which will then break down the capacitor and cannot be used.
There are harmonic currents: high-order harmonic currents are superimposed on fundamental currents, resulting in an increase in total current, causing capacitor load overload, internal expansion, and explosion.
Buying inferior capacitors: In order to reduce costs, some manufacturers on the market use low-quality materials to produce capacitors, which greatly reduces the actual withstand voltage and life of such capacitors.
The structural characteristics of film capacitors and the impact of the use environment on their performance:
Film capacitors are usually composed of polypropylene film, aluminum foil and plastic shell. Polypropylene film is sensitive to high temperature, which accelerates its aging and shortens the life of the capacitor. In addition, a humid environment will also cause water vapor to enter the capacitor, affecting its performance.