| 摘要 |
1,025,441. Semi-conductor circuits. INTERNATIONAL BUSINESS MACHINES CORPORATION. Jan. 2, 1963 [Jan. 15, 1962], No. 246/63. Heading H3T. [Also in Division G4] A switching circuit, e.g. for producing sharp pulses comprises two tunnel diodes X 10 , X 2o . Fig. 2, having series load resistors R 1 , R 2 respectively, connected in parallel across a supply: resistor R 1 is smaller than R 2 , so that more current flows through diode X 10 than diode X 20 . Increasing the current supplied causes diode X 10 to trigger to its high resistance state increasing the current through diode X 20 , and producing the leading edge of the output pulse E out , Fig. 3, after the inherant delay time of a tunnel diode, diode X 20 switches its state producing the trailing edge of the pulse E out . A backward diode B.D. may be connected in the output circuit to present positive overshoot at the end of the pulse. In a second embodiment, Fig. 4, a number of tunnel diodes Xa ... Xe are connected to form a sequential register resistor Ra1 is of lower value than the others, so that its first triggering pulse switches diode Xa to its high resistance condition, but leaves the others unchanged. The change in resistance of diode Xa increases the standing bias on diodes Xb so that the next triggering pulse will switch this diode and increase the bias on Xc ready for the third pulse, and so on until all diodes are switched. The " sequencing " property may be employed in a word recognition circuit, Fig. 6. Detectors of strong frictioning Fs voicing V and weak frictioning Fw are connected to word recognition blocks each of which comprise tunnel diode registers of the type described above. The circuit of Fig. 4 may be modified to form a counter, Fig. 7 (not shown) by connecting all the trigger inputs to a common pulse source so that each pulse to be counted changes the state of one diode. The circuit of Fig. 2 may be used as the source of pulses for such a counter. |
