Improvements in or relating to staircase waveform generator circuits

摘要

876,376. Valve pulse generating circuits. BUSH & RANK CINTEL Ltd. Sept. 28, 1959 [Sept. 29, 1958], No. 31039/58. Class 40(6) The Specification relates to staircase waveform generators of the type in which the charge on a capacitor 10 is transferred in steps to a second capacitor 12. As shown, valve 3 is normally cut off by bias from potentiometer 9 so that the anode is at the potential of the slider of potentiometer 5. Each positive input pulse A drives valve 3 into conduction, discharging capacitor 10 until the anode voltage falls to 250V when the discharge is terminated by the catching diode 7 as shown at B. Capacitor 12 is charged negatively via diode 11 by an amount dependent on the relative capacitance of the two capacitors and adjustable by variable resistor 5. At the end of each pulse A, capacitor 12 retains its new voltage as shown at C. Subsequent pulses A reduce the voltage of capacitor 12 by equal steps. The staircase waveform C is fed via the cathode follower 13 and a D.C. restorer 17 to an output terminal 16. The cathode of diode 11 is clamped to valve 13 cathode potential by diode 19 at the end of each pulse A thus preventing change of voltage of capacitor 12. The staircase waveform is also inverted by valve 25. When the voltage at the anode of valve 25 has reached a value corresponding to the desired amplitude of staircase waveform, valve 29 conducts, cutting-off valve 31 to provide a step D which is fed via a cathode follower 39 to drive diode 42 into conduction, causing diode 43 to discharge capacitor 12 in readiness for the next pulse A. A positive inhibiting voltage may be applied via terminal 44 and diode 45. Specification 876,377 is referred to.