Polyester Capacitor 104j

4 min read Jun 26, 2024
Polyester Capacitor 104j

Polyester Capacitor 104J: Understanding Its Characteristics and Applications

What is a Polyester Capacitor 104J?

A polyester capacitor 104J is a type of film capacitor that uses polyester film as the dielectric material. The "104J" denomination refers to the capacitor's capacitance value, which is 100nF (nanofarads) with a tolerance of ±5%. The "J" suffix indicates that the capacitor has a maximum operating temperature of 125°C.

Construction and Characteristics

Polyester capacitor 104J is constructed by sandwiching a thin layer of polyester film between two metal electrodes. The polyester film is thin and flexible, allowing for a compact design and high reliability. The capacitor's characteristics include:

High Capacitance Density

Polyester capacitor 104J has a high capacitance density, meaning it can store a large amount of electrical energy in a relatively small package.

Low Equivalent Series Resistance (ESR)

The capacitor's low ESR reduces energy losses and heat generation, making it suitable for high-frequency applications.

High Insulation Resistance

The polyester film dielectric has high insulation resistance, ensuring minimal leakage current and maintaining the capacitor's capacitance over time.

Wide Operating Temperature Range

The capacitor can operate within a temperature range of -40°C to 125°C, making it suitable for various industrial and commercial applications.


Polyester capacitor 104J is commonly used in various electronic circuits, including:

Power Supply Filtering

The capacitor's high capacitance density and low ESR make it ideal for filtering and decoupling in power supplies.

Audio Equipment

Polyester capacitor 104J is used in audio equipment, such as amplifiers and filters, due to its high-frequency capabilities and low noise characteristics.

Medical Devices

The capacitor's reliability and high insulation resistance make it suitable for use in medical devices, such as defibrillators and patient monitoring systems.

Automotive Systems

Polyester capacitor 104J is used in automotive systems, including ignition systems, wipers, and lighting circuits.


Polyester capacitor 104J is a versatile and reliable component widely used in various electronic applications. Its high capacitance density, low ESR, and high insulation resistance make it an ideal choice for power supply filtering, audio equipment, medical devices, and automotive systems. When selecting a polyester capacitor 104J, ensure that it meets the required specifications and operating conditions to ensure optimal performance and reliability.

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