We found this circuit in a 1986 documentation. It uses only LEDs, batteries, resistors and the power supply which can consist of 4 batteries or a 9V battery. The basic circuit uses two-color LEDs.
By the components used this circuit of old English documentation can still be easily assembled. The...
We found this circuit in Electronics Now magazine from 1996. The frequency is basically given by...
We found this circuit in a 1980s documentation. Equivalent components can be used. The circuit...