| 摘要 |
measurement technology. SUBSTANCE: device is used in construction, repair and current maintenance of railroad track. The device has an electromagnetic transducer for detection of tie cover plate. Transducer outputs are connected with differential amplifier and reference signal channel in the form of summing amplifier. The first input of synchronous detector is connected to differential amplifier output. The second input is connected to output of reference signal channel, and outputs to input of threshold device whose output forms device output. Electromagnetic transducer has a generator of alternating voltage, condenser, radiation frame and two reception frames connected to transducer outputs. Connected to input of alternating voltage generator is output of feedback device. Radiating frame is made of two half-frames whose outputs are connected with output of alternating voltage generator for summing of their magnetic fluxes and provision of voltage equality and phase opposition. Coupled to other outputs of half-frames is a condenser. Input of feedback device is joined to communication circuit of alternating voltage generator with the half-frames. Reception frames are symmetrically located with respect to radiation frame. EFFECT: increased noise immunity at simultaneous simplification of device design. 2 cl, 2 dwg of device
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