Accession Number : ADD012792

Title :   Digital Phase Meter Apparatus.

Descriptive Note : Patent,

Corporate Author : DEPARTMENT OF THE AIR FORCE WASHINGTON DC

Personal Author(s) : Evans,Joseph T , Jr ; Munechika,Stacy M ; Norris,Michael C ; Hren,Alisa M ; Heck,Kevin M

Report Date : 31 Mar 1987

Pagination or Media Count : 12

Abstract : A digital phase meter to measure the phase difference between an input signal and a reference signal and output this phase information in the form of an eight bit number. The input signal and the reference signal, which are sinusoidal, are conditioned to a more defined leading edge by a high speed differential voltage comparator and a dual/differential line receiver. A series of uniquely configured D flip-flops are used to detect the leading edge of both the signal input and the reference input. An AND gate then acts as a switch that is activated on the leading edge of the signal input. The time interval between the two positive leading edges of the input signal and reference signal specifies the phase difference. The AND gate is in the high state for this duration. The phase difference is converted into an 8-bit binary number via two 4-bit cascaded counters. The high output of the AND gate is used to enable the counters for the duration of the phase difference.

Descriptors :   *PATENTS, *PHASE METERS, *DIGITAL SYSTEMS, RELAXATION OSCILLATORS, RECEIVERS, OUTPUT, LEADING EDGES, SIGNALS, TIME INTERVALS, MEASURING INSTRUMENTS, TIME, INPUT, INPUT OUTPUT DEVICES, PHASE SHIFT, FLIP FLOP CIRCUITS, GATES(CIRCUITS)

Subject Categories : Electrical and Electronic Equipment
      Test Facilities, Equipment and Methods

Distribution Statement : APPROVED FOR PUBLIC RELEASE