In fact, this 1967 Electronic Design circuit generates two symmetrical ramps whose frequency depends on the values of the components used. Modern equivalent transistors can be used.
This circuit is from a Popular Electronics from the 90s. The circuit has a tone frequency...
This solar powered circuit was found in a 1991 documentation. The transistor is a general purpose...
This circuit is based on a common cathode 7-segment display. The circuit is based on CMOS...