20A dual-stage EMI power line filter for 3-phase 3-wire or 3-phase 4-wire AC power system, features compact, easy to install and excellent performance, which is widely used in servo system, automation equipment and machine tools, including 3 phase motor drives, printing equipment, packaging equipment, textile equipment, industrial air conditioners, UPS, communication equipment, etc.

Specification

Dimensions (Unit: mm)

• 3-phase 3-wire line filter

• 3-phase 4-wire line filter

Electrical Schematic

• 3-phase 3-wire line filter

• 3-phase 4-wire line filter

Tips: Band pass filter vs. band stop filter

1. Definition & performance

• Band pass filter: allows certain frequency band signal to pass through, and restrains lower or higher than the certain frequency band signal, interference and noise.
• Band stop filter: restrains certain frequency band signal and allows signals outside the certain frequency band to pass through.

2. Working principle

A perfect band pass filter should has a complete flat pass band without amplification or attenuation in the pass band, and all frequency outside pass band would be attenuated completely. Besides, the conversion outside pass band will be completed within very small frequency range. Actually, no perfect band pass filter existed. Filter can’t attenuate all frequency outside the expected frequency range completely, especially outside the requested pass band there is an attenuated but not insulated range. This is usually called filter roll down phenomenon, and expressed with attenuation fluctuation dB value of every 10 times frequency. Usually, filter design would try to guarantee roll down range as narrow as possible, in the case filter performance will get closer to design. But, with the roll down range getting smaller, pass band will no longer flat, starting to appear “ripple”. This phenomenon is obvious at pass band edge, which is called Gibbs phenomenon. Band stop filter can pass most frequency component, attenuating the certain range frequency component to extremely low level. It’s opposite with band pass filter definition. Among them, notch filter is a special band stop filter, whose stop band range is very small, and has very high Q factor.