This old circuit, from the 80's, uses an integrated circuit that is uncommon today. The circuit is intended for loads controlled by triac and the resistors depend on the desired control.
This circuit was found in an American documentation from the 60's. The transistors are from the...
This oscillator is indicated for the adjustment of FI of FM radios, having its frequency...
This configuration triggers an external circuit or simply an LED for time given by R1 and C1 (T =...