Method of detecting phase pulse signals from an AC distribution line

DETAILED DESCRIPTION It is therefore an object of the present invention to provide a method of detecting the levels of phase pulse signals which can efficiently prevent the occurrence of ghost pulses due to subsequent oscillations.
In accordance with the present invention, a pilot channel of a predetermined phase angle width is set with a phase angle reference point of an a.
c.
voltage wave acting as a reference.
A pilot signal and phase pulse signals are injected by a transmitter into the pilot channel and into other channels subsequent to the pilot channel, respectively.
The reception threshold level is set to a level considerably lower than the peak level of the pilot signal when the pilot signal is received by a receiver in the pilot channel, and the levels of phase pulse signals are detected on the basis of the reception threshold level.
This arrangement can efficiently prevent the occurrence of ghost pulses due to subsequent oscillations when phase pulse signals are received.