This triac circuit turns on a load after a time of 8 to 80 seconds adjusted by potentiometer R7. The circuit is from a Radio Electronics from June 1970.
This micro AM radio will tune strong stations in the frequency range between 530 and 1,600 kHz....
This circuit was obtained in a Electronics World of 1968. The transistors can be equivalent as the BC558...
Based on an integrated circuit of the time, this circuit appeared in the October 1979 issue of...