Patent ID: 6842517

Claim:
A filtering circuit for filtering out meter pulses of analog telephone connections, consisting essentially of: a plurality of resistors; a plurality of capacitors connected to said resistors such that an RC filter is formed for filtering out the meter pulses; said resistors and said capacitors connected in a form of a twin-T section; two of said resistors being connected in series forming a first series circuit having a center connecting node between said two of said resistors; two of said capacitors being connected in series forming a second series circuit having a center connecting node between said two of said capacitors; a common ground line; an input line branching and connected to both said first series circuit and said second series circuit; an output line branching from and connected to both of said first series circuit and said second series circuit on a side opposite to said input line; a further one of said capacitors having a first terminal connected to said common ground line and a second terminal connected to said center connecting node of said first series circuit; a further one of said resistors having a first terminal connected to said common ground line and a second terminal connected to said center connecting node of said second series circuit; and said further one of said capacitors exhibits twice a capacitance of each of said capacitors in said second series circuit and said further one of said resistors exhibits half a resistance of the resistance of each of said resistors in said first series circuit.