Patent ID: 9513308
Filing Date: 2016-12-06
CPC Classification: F41A,F42C,G01P

Claim Text:
1. A muzzle velocity measuring apparatus comprising a detector configured to include a pair of cores, each of the pair of cores encircled by a probe wound coil and installed in two separate positions in an adapter, and to output a muzzle velocity signal based on eddy current signals generated by the probe wound coils when a bullet fired from a bullet chamber passes through the adapter; a muzzle velocity calculator configured to calculate a flight speed of the fired bullet based on the muzzle velocity signal; and a transmitter configured to transmit the calculated flight speed to the bullet, wherein the detector comprises a pair of bridge circuits, each of the bridge circuits includes one of the probe wound coils and generates a respective one of the eddy current signals, a pair of differential amplifiers, each of the differential amplifiers connected to a respective one of the bridge circuits and amplifies a respective one of the eddy current signals, a pair of phase sensitive detectors, each of the phase sensitive detectors connected to a respective one of the differential amplifiers and removes noise from a respective one of the amplified eddy current signals and outputs a respective phase sensitive detector signal, a pair of low pass filters, each of the low pass filters connected to a respective one of the phase sensitive detectors and receiving a respective one of the phase sensitive detector signals and outputting a respective low frequency band signal, and an OR gate connected to the pair of low pass filters and receiving the low frequency band signals and outputting the muzzle velocity signal.