Patents Assigned to Siegfried Preyer
  • Photoelectric measurement of moving filamentary material
    Patent number: 4436427
    Abstract: A light source is energized by pulses controlled by a frequency standard taken from a resonant circuit output. The resonant circuit acts as a narrow-band filter and comprises the capacitance of a photoresponsive receiver and an associated inductor so that a desired filter frequency is obtained. The accurate coincidence of the light source pulse frequency and the resonant circuit acting as a narrow-band output filter permits optical interference acting on the measuring apparatus to be effectively suppressed.
    Type: Grant
    Filed: February 9, 1982
    Date of Patent: March 13, 1984
    Assignee: Siegfried Preyer
    Inventor: Hermann Schwartz