GB470010A - Process of generating saw-tooth electric vibrations or triangular wave-forms - Google Patents

Abstract

470,010. Valve generating circuits. MICHAELIS, E. (Kinne, E.) Feb. 6, 1936, No. 3624. [Class 40 (v)] Oscillations of saw-tooth or triangular waveform are produced by a back-coupled valve circuit tuned to the desired frequency by a condenser and with the back-coupling effected by an iron-cored transformer. A stepped wave-form is produced by a circuit of the super-regenerative type. As shown in Fig. 5, the grid circuit of a valve R is tuned by a condenser C1, and a coil L2 connected to the valve anode is coupled to the grid coil L1. The oscillations are taken off across a resistance W2, or a tuned circuit, in the anode supply circuit. For producing saw-tooth oscillations, the core of the coils L1, L2 is solid and may be of nickel-iron alloy or of steel. If a laminated or divided core is used, e.g. alternate laminae of chemically-pure iron, and steel stampings, a triangular wave-form results. The coils may also carry a direct current. The condenser C1 may be constructed so that its plates resonate mechanically at the desired frequency or at a multiple thereof. Fig. 6 shows a superregenerative circuit in which, in addition to the back-coupling L3, L4, tuned to the desired frequency, a second back-coupling is afforded at a higher frequency by a circuit L5, L6, C6, the coil being centre-tapped to the valve cathode. This introduces steps in the waveform at the higher frequency of the circuit L5, L6, C6. The Specification states the dimensions of the various elements for operating at line or frame frequencies in television.