process for converting mercaptans or mercaptiden in disulfide in a two-phase, which through a kohlenwasserstoffoel phase and the other phase by a waesserige alkalihydroxydloesung is formed

摘要

754,356. Transistor amplifiers. PHILIPS ELECTRICAL INDUSTRIES, Ltd. May 28, 1954 [June 1, 1953], No. 15827/54. Class 40 (6). In a negative feedback cascaded amplifier employing an odd number of transistors with D.C. connection 7, 8 between each collector and the base of the succeeding transistor, the emitter circuit of the last transistor 3 includes an impedance 9, 10, 11 to. which the emitters of the earlier transistors 1, 2 are connected. The current flowing in the resistor 11, which is common to the emitter circuits of the first and last transistors is substantially equal to the collector current of the last transistor which is thereby linearized. The connection to the emitter of transistor 2 provides positive feedback. A common control 20 varies the value of resistor 11 and hence the feedback and also the tapping on potentiometer 21 which determines the bias potential on the base of transistor 1. A small capacitor 14 may be employed to provide phase correction and the impedances 9, 10, 11 may be shunted to give frequency-variable feedback. The circuits 7, 8 may include impedances capable of passing D.C.