Passive magnetic positioning circuit for cable logging tractor

The utility model relates to the technical field of petroleum logging, in particular to a passive magnetic positioning circuit for a cable logging tractor. Comprising a CCL magnetic positioning coil, a relay, blocking capacitors C1 and C2, a cable and a tractor acquisition amplification circuit, one end of the coil of the relay is connected with a tractor power supply, the other end of the coil of the relay is grounded, one end of the CCL magnetic positioning coil is grounded, the other end of the CCL magnetic positioning coil is connected with a common contact end of the relay, and a movable contact of the relay is connected with a normally closed contact or a normally open contact of the relay. A normally closed contact of the relay is connected to a cable through a blocking capacitor C1, the cable is connected to a signal acquisition system, a normally open contact of the relay is connected to an input end of the tractor acquisition and amplification circuit through a blocking capacitor C2, and an output e