2 results about "Preselector" patented technology

The low-grade fluorite mine dry type preselector comprises a machine shell and a rotating ring, the top end of the machine shell is fixedly connected with symmetrically-arranged pumping and discharging openings, a plurality of sliding grooves arranged in an array mode are formed in the pumping and discharging openings, limiting grooves are formed in the positions, corresponding to the bottom ends of the sliding grooves, of the pumping and discharging openings, and filter screens are slidably connected into the pumping and discharging openings. Limiting grooves are formed in the filter screen, limiting blocks are fixedly connected to the positions, corresponding to the limiting grooves, of the filter screen, a plurality of supporting rods arranged in an array mode are fixedly connected to the top end of the filter screen, inner rods are connected to the supporting rods in a sliding mode, and round blocks are fixedly connected to the top ends of the inner rods. The filter screen is convenient to clean, through holes in the filter screen are prevented from being blocked by dust and impurities, and the filter screen is prevented from being blocked to affect use of the sorting machine.

The application discloses an automatic level adjusting system and method for pulse signals, and belongs to the technical field of electronic measurement. The system comprises: in the superheterodyne receiving channel, the system draws out a radio frequency signal through a power divider after a preselector, converts the radio frequency signal into a voltage through a detector, compares the voltage with a digital control reference voltage in a subtraction circuit, and obtains a difference signal. The difference signal is collected by an FPGA and it is judged whether the difference signal exceeds a preset range, and if so, an interrupt is triggered. A CPU responds to the interrupt, adjusts the attenuation of an input attenuator and the switch state of a low noise amplifier according to the polarity and amplitude of the difference signal and according to a preset rule, and forms a closed loop feedback control. The application effectively solves the problems of measurement distortion, low efficiency and equipment damage risk caused by improper manual setting when testing unknown pulse signals, realizes adaptive optimization of a dynamic range, and improves the reliability and accuracy of automatic testing.