The difference between this circuit and the previous one is that it uses PNP transistors. The circuit is from Radio Electronics magazine from July 1968. The frequency depends on R1 and C1.
This circuit was obtained in a Motorola manual, but it applies to almost any operational...
Found in a 1990s Motorola documentation, this circuit aims to protect a triac that drives an...
Found in a 1968 documentation, this small amplifier was very popular at the time being used in...