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 appears on this site from different sources. This is from documentation from the...
The circuit shown in the figure consists of a low voltage drop (LDO) regulator for 200 mA using the...
The operating principle of the VCO shown in the figure is the same as the CIR4598 circuit. The...