This circuit generates quadrature signals, that is, with a 90-degree phase difference. The circuit must be powered by a symmetrical source and the frequency depends on the capacitors.
We find this circuit in a 1970 publication. Transistors can be replaced by current equivalents and LDR is...
Featuring low output impedance and high input impedance, this configuration was found in a 1980s...
Found in a 1980s American documentation, this circuit can use a SCR and a general-purpose transistor....