This circuit is from a Radio Electronics from October 1963. The transistor is a power transistor of the time, and two transformers are used. The input has 10k impedance and is powered by 12 V.
This circuit was originally designed to monitor the temperature of a vehicle. The integrated...
This circuit was obtained in a Popular Electronics of the 90s. It warns when the indicator lamp is...
This amplifier circuit with two transistors was found in a Mullard transistor manual from 1960. The...