Found in a 1964 Electronic Design this circuit makes use of components of the era. The output is 2 V peak to peak and the input is 2 V. The maximum frequency depends on the employed components.
The load used in this experimental circuit is a small incandescent lamp but it can be replaced by...
Found in an American documentation from 1968, this circuit senses the temperature through an...
Today we have more compact solutions. This is from a Radio Electronics magazine from October 1990....