| 摘要 |
1,006,016. Electronic counters. INTERNATIONAL BUSINESS MACHINES CORPORATION. Aug. 27, 1962 [Aug. 29, 1961], No. 32799/62. Heading G4A. The stages of a binary counter respond to the beginning of a pulse to be counted whereas auxiliary elements conditioning the stages for for response are affected by the end of said pulse. The counter is made up of a number of circuits shown in Figs. 2-5. An L block, Fig. 2, operates as an AND gate followed by an inverter. A dot OR or L1 block, Fig. 3, operates so that if all the inputs are 0 the output is 1 while if any input is 1 the output is 0. Fig. 4 shows the basic bi-stable element of the counter and comprises two L blocks in which a +vegoing pulse applied to 40 sets the element and locks it in set or 1 condition. Likewise a + ve going pulse applied to 42 resets the element to 0 condition. Fig. 5 shows a driving amplifier D. Each bi-stable pair of L blocks 50, 51 of the stages 10-15 of the counter is controlled by the outputs of steering elements S1-S3 through L and L1 blocks so that according to whether the counter is set to forward or reverse operation so those stages which are to reverse at the next pulse receive a +ve-going pulse on the set or reset lead as the case may be. The change-over takes place at the beginning of the count pulse. After the change-over the counting stages control the steering elements S1-S3 through further L and L1 logic blocks so that the necessary changes are made at the end of the count pulse. Resetting. The counter resets to zero automatically. Alternatively a predetermined number set up on leads 119 can be entered when lead 117 is marked. Further the counter can reset when it attains a predetermined number, gate 121 as an example changing the capacity of the counter to 26. |
