Limiter

limiter [′lim·əd·ər]

(electronics)

An electronic circuit used to prevent the amplitude of an electronic waveform from exceeding a specified level while preserving the shape of the waveform at amplitudes less than the specified level. Also known as amplitude limiter; amplitude-limiting circuit; automatic peak limiter; clipper; clipping circuit; limiter circuit; peak limiter.

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limiter

A special-purpose fuse (usually of high current-interrupting rating) designed to protect an electrical circuit or equipment from the effects of high available short-circuit current by limiting the amount of current permitted to flow through it.

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Limiter 

(in electronic engineering), a device that provides a constant output voltage level when the value of the input voltage exceeds a limiting threshold. Limiters are used extensively in pulse technology to shape and transform pulses and in radio broadcasting and multichannel communication apparatus to limit signal levels. Amplitude limiters provide a specified maximum level for the amplitudes of the fundamental oscillation (first harmonic); limiters of instantaneous values “clip off” any overshoots of oscillations.

The operation of a limiter depends on abrupt change in the conductivity of a nonlinear component (transistor, semiconductor

Figure 1. Circuit of a limiter and curves explaining its operation: (A) operating characteristic of the limiter; (B) curve of the input voltage U_in; (C) curve of the output voltage U_out; (U_u1) and (U₁₁) voltages of sources of emf in the diode circuits that determine the lower and upper limiting thresholds, respectively; (U₁) and (U_u) lower and upper levels of the limited voltage; (U_inst) instantaneous value of the oscillation amplitudes; (a – b) linear portion of the limiter characteristic; (R) limiting resistor; (R_L) load (output) resistor; (D₁) and (D₂) semiconductor diodes

diode, electron tube, and so on) when the amplitude or instantaneous value of the input voltage reaches the limiting threshold; because of this, a futher increase in the amplitude or instantaneous value of the output voltage is stopped (see Figure 1). A distinction is made between limiters with unilateral operation (with only an upper or lower limiting threshold) and clipper-limiters.

V. M. TIMOFEEV