Belling Lee EMC Mains Filters

With the continuing development of electronics and its applications into most areas of human activity it is important to recognise the increasing danger of reducing the reliability of equipment through electromagnetic interference. Unplanned coupling of spurious signals into equipment can cause inadvertent initiation of sequences leading to unplanned events and happenings which can lead to corruption of data, loss of revenue and danger to life.

Spurious signals may be generated by natural origin eg. Lightning or electrostatic discharge etc as well as locally by switches or transient voltages associated with normal daily activities and operations at work or in the home.

In all equipment which functions in response to controlling signals via a coupling medium, spurious signals are input as a parallel coupling medium such as stray capacitance which can allow a spurious signal to appear along with the controlling signals to the detriment of the systems performance and reliability.

It is considered that next to free space, the most pervasive coupling medium is the mains electricity supply with its current carrying conductors providing a direct connection between equipment taking mains power.

Belling Lee mains filters have been developed to provide methods of achieving electromagnetic compatibility, EMC, whereby equipment mutual interference is kept within acceptable bounds by limiting susceptibility and emissions caused by spurious signals.
The provisioning for the incorporation of a filter in the supply line of electronics equipment has become an integral part of design procedure to reduce spurious signals and enhance equipment reliability.