Discriminator(redirected from discriminators)
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a device that transforms a change in a control parameter of an electrical signal (at the input) into a change in the voltage (at the output).
In a discriminator the values of a parameter (amplitude, duration, polarity, frequency, and phase) of an input signal are compared to a selected (nominal) value of the parameter of a separate (reference) signal source. As a result of the comparison, a difference (misalignment) voltage arises at the output of the discriminator. Its amplitude and polarity are determined by the degree and sign of deviation of the value of the given parameter of the input signal from the nominal signal.
Discriminators are classified according to the signal parameters being compared. A pulse-height discriminator has a set triggering level and passes only signals with an amplitude higher (lower) than the nominal value. When the input and reference impulse signals coincide in time, the signal appears at the output of a time discriminator constructed as a coincidence circuit and disappears at the output of a discriminator constructed as an anticoincidence circuit. In frequency and phase detection the variations of high-frequency frequency- and phase-modulated oscillations are transformed by the discriminator into amplitude-modulated oscillations, which in most cases are then delivered to a detector. In this case, a reference signal with a fixed initial phase is used in the phase discriminator. Discriminators are used in systems for automatic control of automation and remote-control devices, in frequency and phase detectors of radio receivers, in devices in nuclear physics, and in measurement technology.
REFERENCESRadiopriemnye ustroistva, part 2. Moscow, 1963.
Frolkin, V. T. Impul’snye ustroistva, 2nd ed. Moscow, 1966.
Gonorovskii, I. S. Radiotekhnicheskie tsepi i signaly, part 2. Moscow, 1967.
IU. B. LIUBCHENKO