This servo circuit was found in 1969 Motorola documentation. Integrated circuits and transistors are types of the time, hard to find today.
This circuit converts square (rectangular) signals into triangular signals with typical 16 V...
The transistors of this circuit found in an English 1980s documentation may be the modern BC548...
In the figure we have an AND gate with the LM3900 operational transconductance amplifier. The...