POWER LINE CARRIER-USE MODEM COUPLING CIRCUIT

摘要

A modem coupling circuit comprising a transformer (1) having a core (1a) forming a gap, primary windings (N1a, N1b) for providing to this core (1a) bifilar windings connected to power lines (L1, L2) as a one-layer structure, a secondary winding (N2) forming a sandwich structure along with this one-layer-structure primary winding and connected to a transmission circuit (2), and a secondary winding (N3) connected to a reception circuit (3), a coupling capacitor (C1) connected to the middle point of primary windings at terminals not connected to the power line (L1, L2) sides, current limiting resistors (R1a, R1b) connected to primary windings (N1a, N1b) of a bifilar winding structure, drive resistors (R2a, R2b) connected to a transmitting secondary winding (N2), and terminal resistors (R3a, R3b) connected to a receiving secondary winding (N3).