the power signal to the power regulation circuit 140 the power regulation circuit 140 may include a diode arranged in series with a step down voltage regulation to bring the dc voltage level down to the appropriate level for the slave device the designer has the option of using the same inductors for elements 110 112 132 and 134 similarly to the arrangement on the master side the first side of the secondary winding of inductor 132 is coupled to signal line 152 of slave transceiver 160 and second side of the secondary winding of inductor 134 is coupled to signal line 154 of slave transceiver 160 while the second side of inductor 132 and the first side of inductor 134 are coupled directly to each other a second impedance matching network 155 including a voltage divider and a capacitor is arranged in parallel to inductors 132 134 across input lines 152 154 between the inductors and the slave transceiver 160 in terms of operation when master transceiver 102 transmits a differential voltage v then a voltage v 2 occurs across each of the series connected primary windings of inductors 110 112 which have equal inductances and turn ratios owing to the magnetic coupling of the primary and secondary windings the voltage across the secondary windings of inductors 110 112 is also v 2 with the exception of a small dc bias voltage owing to the dc current supplied to the slave the polarity of the voltages is in accordance with the dot convention the inductors provide high impedance to the ac communication signals but essentially no impedance to the dc power rail voltage this allows dc power to be transmitted without significant.