A detector for detecting passing magnetic articles including a magnetic-field-to-voltage transducer having an output at which an analog voltage Vsig is generated, with the Vsig voltage being commensurate to the strength of the ambient magnetic field and having at least one peak. An analog-to-digital converter coupled to the output of the transducer is operative to convert to a corresponding digital signal at least a portion of the Vsig voltage, which portion includes the peak and a circuit coupled to the analog-to-digital converter is operative to generate an output signal indicative of the occurrence of the times t.sub.xpk when the difference between Vsig and said peak of Vsig has exceeded a predetermined amount.