US Patent 7585354 Wet scrubbing apparatus and method

In order to provide a phase detector and a method of phase detection which are distinguished by greater sensitivity and simple implementability, at least one differential signal of two input signals (Ua; Ub) may be formed over at least one predefined period by means of a first subtracter (12), at least one maximum value of the at least one differential signal may be detected by means of a first peak detector (16) and at least one minimum value of the at least one differential signal may be detected by means of a second peak detector (18) and at least one further differential signal (UOut) may be formed from the at least one maximum value and the at least one minimum value by means of a second subtracter (14).