With over 7 Million Mica Capacitors in stock, make R&J Components Corp. your source for Mica Capacitors. Mica is a stable, inert material mined in India. When used as a dielectric, it is very stable and reliable. The standard temperature of Mica Capacitors is -55° C to +125° C and common values include 240pF, 270pF and 300 pF. Cornell Dubilier is the largest manufacturer of Mica Capacitors and R&J Components stocks a tremendous inventory of all of the following series:

• CMR – High Reliability
• CDV – High Voltage
• CDS – Single Coat Mica

 Currently, Cornell Dubilier is the only manufacturer that is qualified (or QPL’d) to make Type CMR Series capacitors. The CMR series is a high reliability capacitor (.01%/1,000 hours failure rate) and meets requirements of MIL-PRF-39001. It is ideal for applications such as computers, jetcraft, missiles and other military and high frequency applications. The voltage of Cornell Dubilier’s CMR series capacitors runs from 50 Vdc to 500 Vdc. The capacitance runs from 1 pF to 91,000 pF.

Film Capacitors come in two standard designs, a film-foil combination where plastic or paper films are interleaved with metal foils that serve as electrodes, or as a Metalized construction where film has aluminum or zinc deposited in it to serve as the electrodes.

Metalized film capacitors show there advantages where smaller applications are needed due to their smaller size and lower weight. Metalized capacitors also have a built in “healing” property where in the case of voltage stress the film will clear itself and heal the point of damage. Due to this “healing” property most metalized film capacitors are tolerant of overvoltage.

Circuits which require high currents may need a film-foil combination capacitor. The heavy foil of this combination offers low electrical resistance and excellent thermal dissipation preventing internal hot spots and optimizing the circuit efficiency.

Impregnated capacitors are recommended for high voltage circuits where corona may be a problem. Wax is suitable for a lower temperature application. For higher temperature application oil is a suitable impregnant. These capacitors can be either metalized or film-foil combination. Also, series wound units are used to prevent corona.

The shelf life of our Metallized Film AC and DC Capacitors is essentially infinite, if capacitors are stored unenergized in a non-corrosive environment and without damage at any temperature between -40C to +90C. Operating temperature is -40C to +70C.

Electrical characteristics are expected to remain stable for at least ten (10) years or longer.

“Across-the-Line Capacitors”, or X Capacitors, serve a crucial role in many EMI (Electromagnetic Interference) and RFI (Radio Frequency Interference) applications. “Across-the-Line” Capacitors suppress electrical noise, provide protection against shock and provide operational insulation. Generally the dielectric of these “safety” capacitors are encased in a flame retardant case.

X Capacitors can be classified into three subclasses: Class X1, Class X2 and Class X3. The most common of these classes are X1 and X2. X1 Capacitors have enhanced impulse ratings and are used where very high transients (or high amplitude sounds) are likely to occur. X2 Capacitors are more often used in more general applications.

Another type of “safety” capacitor that suppresses RFI is a Y Capacitor or “Line-to-Ground” Capacitor. Unlike the X Capacitor, the Y Capacitor is designed to be connected between a current carrying conductor and a grounded conductor. The X Capacitor, on the other hand, is connected between two current carrying conductors or AC lines. Y Capacitors are manufactured in four classes; Y1, Y2, Y3 and Y4. The most common are Y1 and Y2.

Both X and Y Capacitors are rated according their voltage and peak pulse voltage. The peak pulse voltage indicates the extreme conditions, such as power surges and lightning strikes, these capacitors are able to withstand. Most household appliances contain X2 or Y2 capacitors. X2 Capacitors are impulse tested to 2.5kV and Y2 Capacitors are impulse tested to 5kV. However, when over-voltage occurs, these “safety” capacitors can fail. “Across-the-Line” Capacitors failure may result in an applications poor performance or a blown fuse but, there is no imminent danger to the user. “Line-to-Ground” Capacitors, however, can result in electrical shock or worse when the ground connection is lost.

Overall, these “safety” capacitors are designed to handle high voltage impulses while protecting the circuit and the user from harm.

Illinois Capacitor (IC) is a leading manufacturer of high performance capacitors including; aluminum electrolytic, metalized film, power film and supercapacitors. All IC products meet the industry’s highest quality standards. As capacitor technology changes, Illinois Capacitor remains dedicated to providing leading-edge capacitors in a broad range of values and offering engineers more options to enhance performance and lower costs.

Today, Illinois Capacitor is pioneering EDLC technology. Known as “supercapacitors,” Electric Double-Layer Capacitors (EDLC) provides the highest available capacitance values per unit volume and the greatest energy density of all capacitors. For example, Illinois Capacitor’s DCN series of supercapacitors offers capacitance values up to 3,500 Farads in a very small size. Other advantages of supercapacitors include; long life, low ESR, low heating levels during charge and discharge, high output power and improved safety.

Thanks in part to EDLC technology; utilization of Illinois Capacitor products continues to grow across several markets including; the wireless communications, electronic power technology, energy management, solar and wind power markets.