GB773984A - Improvements relating to electronic amplifier circuit arrangements - Google Patents

Abstract

773,984. Transistor and discharge tube. amplifying circuits. METROPOLITANVICKERS ELECTRICAL CO., Ltd. April 15, 1955 [March 19, 1954], No. 8139/54. Class 40(6) In a circuit for amplifying small wanted signals #v, two similar amplifying channels are arranged to float, one in the sum of the unwanted and unwanted signals v + #v, and the other on the unwanted signal v so that only the wanted signal is amplified in each channel, the unwanted signal signal being eliminated in a differential device. The amplified wanted signal is derived by means of a differential device such as a differential circuit or an oscilloscope. The discharge tube V3 is energized from capacitor C1 de-coupled from tht supply by resistors R1, R3. The input at terminal 1P1, v + #v is applied over resistor R3 and appears at the output OP1. The input signal v applied at terminal 1P2 is fed over capacitor C3 to the grid of discharge tube V3, an amplified version m#v appearing at the anode, so that the total signal at OP1 is v + #v (m + 1). In a similar manner the tube V4 provides an amplified signal v-m8v. The signals at OP1, OP2, are subtracted to give an output (2m + 1) #v. In a modification, Fig. 2 (not shown), the input and output are applied over cathode followers. A number of similar stages may be cascaded. In a further modification Fig. 3 (not shown), the discharge tubes V3, V4 are replaced by transistors operating with common emitter connections. The resistors R1, R3 are so large that input cathode followers are not necessary. The circuit may be employed to obtain a push-pull output from a singleended source.