GB627588A - Improvements in or relating to thermionic valve saw tooth wave generators - Google Patents

Abstract

627,588. Saw-tooth or pulse generating circuits. SADIR-CARPENTIER. Oct. 4, 1946, No. 29704. Convention date, May 7, 1945. [Class 40 (vi)] In a generator of saw-tooth waveforms a capacitor is charged at a substantially constant rate through a valve and then rapidly discharged by means of a second valve which is controlled by a third valve, control pulses being applied to both the first and the third valves. In the Figure valves 2 and 4 are normally cut-off, valve 3 conducting to dis. charge capacitor 1. Positive going pulses applied to terminals 8 and 9 cause the capacitor 1 to charge through valve 2, which is preferably a constant current device such as a pentode ; valve 4 is similarly rendered conducting the voltage drop across the anode resistor 5 cutting- off valve 3. At the termination of the positive going pulse valve 4 is cut-off and capacitor 1 rapidly discharges through valve 3 which is then conducting. The controlling pulses may be from different sources, the capacitor then only charging during the period when positive going pulses are present at both terminals 8, 9 simultaneously and only discharging when the positive pulse,at the grid of valve 4 terminates. By varying .the relative duration and time of occurrence of the controlling pulses a variety of truncated saw-tooth wave-forms may be generated, Fig. 3 (not shown).