Pulse discriminator circuit

摘要

A pulse discriminator circuit is specified which, when pulses are transmitted, transfers useful pulses with the correct duration and reliably suppresses short-time noise pulses. The pulse discriminator circuit comprises a pulse-amplitude-normalising stage (3) and a threshold switch (5) with a switching hysteresis which is defined by an upper and a lower threshold value and is located symmetrically between a predetermined upper level and a predetermined lower level. A resistor (9) connects the output (11) of the amplitude-normalising stage (3) to the input of the threshold switch (5). The output signal of the threshold switch (5) is fed back to the input (7) of the threshold switch (5) via a capacitor (17) which is connected into a positive feedback arm (13). A level clamping circuit (19, 19'), which is connected to the input (7) of the threshold switch (5), prevents the input signal of the threshold switch (5) from exceeding the predetermined upper level or dropping below the predetermined lower level. The pulse discriminator circuit only transmits pulses, the duration of which exceeds a predetermined value. <IMAGE>