This classic windscreen wiper interval setup was found in American documentation from the 90s. The circuit can be found with variations at other points on this site.
This amplifier was found in a Japanese publication in 1972. Transistors are uncommon today, and...
The current of this source is 200 mA at the most, and the output depends on the zener that may...
Found in Mallory documentation from 1968 this circuit uses an integrated circuit from that time. The...