This book considers electronic devices applied to process analog signals in in strument making, automation, measurements, and other branches of technology. They perform various transformations of electrical signals: scaling, integration, logarithming, etc. Such devices are considered in tutorials on electronics. The need in their deeper study is caused, on the one hand, by the great demands of extending the range of input signals, as well as increasing the accuracy and speed of such devices, which usually receive insufficient attention. On the other hand, new devices arise permanently, which are not considered in electronic tutorials yet, but already widely applied in practice