Temperature-Compensated DC Transistor Amplifier

The operation of a dc transistor amplifier is greatly affected by drift of the output current. This drift is caused primarily by changes of temperature of transistors since some of the parameters of transistors, like the collector current for zero emitter current, Ico, are very sensitive to temperature. In this paper the problem of the drift in dc transistor amplifiers, caused by changes of temperature, is analyzed and different methods for the solution of this problem are recommended. One of these methods, which provides an effective means for compensation, is based on the use of temperature-sensitive resistors as a compensating element. The second part of this paper contains operating characteristics of such an experimental dc amplifier, employing this method of temperature compensation.