| 摘要 |
<p>1,201,118. Analogue/digital converters. DECCA Ltd. 11 March, 1969 [20 May, 1968], No. 23835/68. Heading G4H. In an angle digitizer of the type in which a gate 23 is opened at a time determined by a reference signal and closed by a signal the time of which is dependent on the unknown angle, clock pulses being counted during the time interval between these signals, signals representing sin # and cos #, where # is for example either the angle through which a shaft has rotated or the phase difference between two signals, are fed via semi-conductor switches 11, 12, receiving modulating signals in phase quadrature, a mixer 17, tuner 18 and squaring circuit 19 to a differentiating amplifier 20 the output pulses from which control the closing of the gate 23. The gate is opened, after an interrogate signal 27 has enabled a switch 22 and reset counter 25, by the next reference signal which is derived from one of the modulating signals. The count may be fed to an indicator or computor.</p> |
