Patent GB-769704-A (GB)
Title: Improvements in or relating to electrical pulse scaling circuits
Inventor: COOKE-YARBOROUGH EDMUND HARRY
IPC: H03K23/00
Filed: 1954-04-15
Abstract: 769,704. Counting-apparatus. UNITED KINGDOM ATOMIC ENERGY AUTHORITY. April 15, 1955 [April 15, 1954], No. 11168/54. Class 106 (1). In an electrical pulse sealing circuit comprising a ring of bi-stable elements each arranged on changing from a first to a second stable state to cause the next succeeding element to change from the second to the first state, one element is arranged on changing to the second state to cause a further element of the ring to change to the first state, a pulse for changing the elements from the first to the second state is applied to all the elements simultaneously, and the elements are reset to a starting condition at the end of each cycle. As shown, four elements a, b, c, d are connected in a ring with a further connection from d to b. Thus, if in the starting condition, element a only is in the " 1 " or " on " state (condition 0, Fig. 2), the first three turnoff pulses will step the " on " state to d (condition 3), and when the next pulse turns off d, element b, as well as a, will be turned on; these two " on "states will be similarly stepped round, and one further on state added. every time d is turned off, until all the elements are "on" (condition 10). Since a further condition with all elements "off could be included, the arrangement of Fig. 2 could provide a scale of up to 12, but, as shown in Fig. 4, the elements are reset to the starting condition 0 after condition 9 to produce a decimal counter. Each element comprises a pointcontact type transistor 20 which can be triggered to the " on " and " off states by positive pulses applied to the emitter and base electrodes respectively. Pulses to be counted are applied through diode d2 to the emitter of a transistor- 21 in a trigger circuit which is self-restoring owing to inductance 2mH in the base electrode circuit, and cause turn-off pulses to be applied from the collector electrode through diodes d3. to the base electrodes of all the transistors 20. A transistor 22, arranged in a similar selfrestoring circuit, is triggered by pulses from the base electrode of transistor 21 through diode d6 and supplies turn-on pulses from its collector electrode to condensers 330pf. Each condenser was charged through diode d4 if the preceding transistor- 20 was previously " on," the condenser between elements a and b being charged also through diode d41 (connection d-b, Fig. 2), and the turn-on pulse discharges any charged condensers to turn on the following transistors 20 through diodes d5. When condition 9, Fig. 2, is detected (elements b, c, d " on ") by diode coincidence gate db, dc, dd, condenser 300 pf is charged and a positive pulse from transistor 22 is transmitted through diode d8 to trigger a further self-restoring circuit comprising transistor 23 which applies a positive pulse to the emitter electrode of transistor 20 of element a and the base electrodes of the transistors of elements b, c, d, to reset the counter to condition 0. Carry pulses for a further decimal counter may be obtained from transistor 23. The turn-on pulses may be obtained from a secondary winding on inductance 2mH, transistor 22 being omitted. Other arrangements comprising three and five elements have a maximum count of 7 and 19. respectively. Other bi-stable elements, e.g. saturable magnetic cores, other ferromagnetic or ferro-electric devices, thermistors, relays, gas-filled tubes and hard valve flip-flop circuits may be used.