What is a core capacitor and classification

The core capacitor is used because it is coated with a metal layer on the porcelain tube and two poles are formed inside and outside. Because the tube is empty, it is called a core capacitor. It is a three-terminal capacitor, but compared with the ordinary three-terminal capacitor, because it is directly mounted on the metal panel, its grounding inductance is smaller, almost no lead inductance, and its input and output are Metal plate isolation eliminates high frequency coupling, and these two characteristics determine the filter effect of the feedthrough capacitor with close to the ideal capacitance. Moreover, it is an ideal device for interference filtering.

Introduction to the core capacitor:

Through the heart capacitance (also known as feedthrough, measurement and control systems, etc.).

Classification of feedthrough capacitors:

1, type C

This is a low-inductance device that avoids high-frequency ground-to-ground noise interference. It is low-cost and suitable for high-impedance sources and high-load applications.

2, L type

This is a feedthrough capacitor with inductive and capacitive components, typically used in circuits with low impedance sources and high impedance loads, and vice versa. Note: The inductive component should face a low impedance source

3, Pi type

The Pi type consists of two capacitive elements and an inductive element between the two capacitive elements, exhibiting low impedance to both the impedance source and the load. Pi type filter provides better high frequency filtering performance than C type and L type structure

Characteristics and applications of the core capacitor:

1) Welded core capacitor

Welded core capacitors are ideal for installations where space is tight;

Application: Mainly used for filtering signals, data lines and AC power lines;

Telecommunications equipment, transmission equipment, microwave filters, industrial computers, composite circuit filter components;

Small size: effective use of space;

Rated voltage: up to 1000VDC;

A variety of circuit structures: C-type, Pi-type, L-type circuits are available;

High temperature construction: it can prevent backflow during installation;

Certification: Filters for MIL-F-15733 QPL and MIL-C-11015 (CK99) certification;

2) Resin sealed threaded core capacitor

The resin-sealed bolt-type core-through capacitor can be easily mounted to the through-hole position with a matching nut and gasket; the resin is sealed at both ends of the solid case to provide good environmental protection;

Application: Mainly used for signal, data line, DC power line filtering; micro-extrusion or screw mounting is ideal for applications where soldering is not suitable, suitable for microwave and other high-frequency applications;

Voltage: up to 2500VDC/240VAC

Certification: Available for MIL-F-15733 certified products

Circuit structure: C type, L type, Pi type

3) High current and high voltage resin sealed through-core capacitor

Application: High current filter is mainly used in high current switching power supply and DC charging system; high voltage filter is mainly used in high voltage power supply and solid bolt type structure for easy installation;

Features: high current up to 100Amps

Voltage: up to 2500VDC and 240VAC@400HZ

4) Glass sealed high performance through-core capacitor

It is sealed with glass and has excellent EMI filtering performance. For those who still require high reliability filtering in harsh environments, this product is the best choice for wide-band high-performance EMI filtering from 10KHz to more than 10GHz, glass sealing series. Highly moisture resistant, corrosion resistant, and resistant to other harsh environments that may be encountered in military applications.

Applications: power supplies, signal lines, rocket ignition devices, aircraft, military communications, medical equipment, multi-stage filtering;

Optimized design: A variety of size and shape, C, L and Pi type circuit for selection, instantaneous suppression Pi, T, & TT circuit optional;

Reliability: Manufactured in accordance with MIL-F-15733 and MIL-F-28861 standards, in line with QPL requirements; based on MIL-F-28861, space application "S" level

FED/MIL certification: MIL-F-15733 and MIL-F-28861 compliant

Features: Insertion loss range 0.01MHz-10GHz

Capacitance and temperature characteristics: 1pF-1μF; NPO, X7R, Z5U, etc.

Temperature range: -55°C-+125°C; -40°C-+85°C

Maximum voltage value: 400VDC 240VAC@400Hz

Maximum current: 30Amps