This circuit was found in documentation from the 1970s. However, it can be implemented with modern transistors such as 2N2222 for Q1 and BF494 for Q2. The crystal depends on the desired frequency.
This 1969 Electronics World power supply has 5 V to power digital circuits and a 170 V output for...
This circuit is from old American documentation intended to trigger the flash of a camera flash with...
This sophisticated NiCad battery charger was found in a 1990s Elektor. The components used are...