GB652175A - Improvements relating to electrical integrating circuits and to electrical counting circuits employing integrating circuits - Google Patents

Abstract

652,175. Valve integrating and pulse frequency dividing circuits. ELECTRIC & MUSICAL INDUSTRIES, Ltd. April 8, 1948, No. 9829. [Class 40 (vi)] In a circuit in which a capacitor in the anodecathode path of a valve is given a charge proportional to the time integral of the potential applied to the control grid-cathode circuit, a negative feed-back connection is provided to the grid proportional to the flow in the capacitor. The circuit is described as applied to a frequency dividing circuit of the stepped waveform type in which the steps are made substantially equal. Pulses, Fig. 2 (a) from generator 2 are fed to the control grid of valve 1, Fig. 1, over differentiating circuit 3, 4, 5 and 14 to produce pulse train, Fig. 2 (b). Due to the negative bias, the positive pulses only are effective to cause anode current to flow, the potential across capacitor 11 falling as in Fig. 2 (c). Negative feed-back over capacitor 13 and resistor 14 causes the anode current to correspond more nearly with the positive pulses on the grid. An impulsive component, Fig. 2 (d), developed across resistor 12 may be made of such magnitude that the resulting step wave, Fig. 2 (e), is of rectangular form by arranging the time constants of the circuits 3, 4, 5 and 14 to be the same as 11, 12. Upon the cathode potential of valve 15 falling sufficiently, an oscillation takes place to discharge capacitor 11, the anode potential of valve 1 rising until diode 24 conducts. Specification 471,731 is referred to.