| 摘要 |
1,032,801. Semi-conductor pulse discriminating circuits. TELEFUNKEN PATENTVERWERTUNGSGESELLSCHAFT m.b.H. March 20, 1963 [March 24, 1962], No. 11038/63. Heading H3T. A pulse amplitude discriminator circuit comprises a tunnel diode connected to a bias current source and a signal current source, the signal and bias currents being in opposition, such that when the signal current overcomes the bias current, the diode switches from a low voltage state to a high voltage state. As described, a pair of series-connected tunnel diodes T u1 , T u2 are biased from variable bias circuits T 2 , R 18 , R 16 and T 3 , R 17 , R 15 so that T u1 will switch when an input pulse at E exceeds the lower limit and T u2 will switch when the input at E exceeds the upper limit. If the signal lies between the two limits T u1 switches and the resulting output pulse from it is fed via amplifier T 4 , T 5 to a differentiating circuit R 1 , C 2 . The negativegoing pulse derived from the differentiated trailing edge is then fed to switch tunnel diode T u4 and produce an output signal at OV. If the input signal exceeds the upper limit diode T u2 also switches and the output from T 5 is of sufficient amplitude to switch on a normally non-conducting transistor T 7 , the collector current of which is sufficient to switch tunnel diode T u3 to its high voltage state. This change in voltage renders transistor T 6 also conducting and the collector current of this transistor is sufficient to prevent diode T u4 being switched by the output from R 1 C 2 , so that no output signal is produced. In order to reset diode T u3 , the next output pulse from T 5 is differentiated and the pulse from the leading edge is fed via diode G on to the cathode of T u3 . In a modification, Fig. 2 (not shown), the outputs from T 5 are taken from a delay line instead of from differentiating circuits. Multilevel discrimination may be obtained by using more than the two diodes T u1 , T u2 in the input circuit. |
