Low loss telephone circuit

A telephone power strip-off circuit for recovering electrical power from a telephone line, comprising:

• a polarity guard sub-circuit including a MOSFET bridge operated in an inverted mode, a line seize sub-circuit, a speech transformer sub-circuit, and a switched mode power supply connected in series across said telephone line, said speech transformer sub-circuit including a single, low impedance transformer with a low D.C. resistance primary winding, and a feedback circuit for making the low impedance transformer behave as a high impedance transformer, said feedback circuit being operative for increasing the A.C. impedance of the transformer by sensing flow of a first A.C. current in said primary winding of said transformer and, in response, causing flow of a second A.C. current in said primary winding to cancel the effect of said first current.