Re: EMI Filters in parallel, PFC question

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: David Speck <dave-at-davidspeckmd-dot-org> 

Bob,
EMI Filters are low pass filter circuits.

If you parallel them, you can double the current capacity of your supply, 
but you will halve the EMI protection (i. e., double the amplitude of EMI 
that will pass the assembly).

If your series them you double the power dissipated within the filter, but 
you will halve the amount of EMI that would get  through one filter.

For most situations, seriesing filters gives no great advantage.  You can 
parallel them if you don't have enough current capacity with one filter 
alone, but you're probably better off getting a larger filter that can 
handle the desired current.

HTH,

Dave


>A quick question-- if one EMI filter rated at 30 A is good, are two in 
>parallel better?