BOREHOLE VIBRATOR CONTROLLED OVER LOGGING CABLE Russian patent published in 1998 - IPC

FIELD: geophysics. SUBSTANCE: proposed borehole vibrator can be used as source of seismic vibrations while studying structure of entrails of earth. Possibility of functioning of this vibrator over three-core logging cable is achieved by placement of winding of phase-frequency feedback transducer between zero of star of phases of vibration motor and load-carrying braiding of cable. Frequency converter is connected on surface to cores of cable. Filter for isolation of signal of transducer which output is connected through frequency and phase discriminator to comparison elements in feedback loop between master generator and unit controlling frequency converter is placed between line cores and braiding. Phase-frequency transducer of borehole vibrator of inductor generator type with ring winding is manufactured with ring magnets having axial magnetization. One of teeth of rotor and stator has smaller radial gap that the rest of them. EFFECT: improved operational characteristics. 1 cl, 2 dwg