This astable multivibrator has an active cycle of 30,000: 1. We found it in a 1970 EEE. The components used are from that time.
This circuit is temperature stabilized. Modern equivalent transistors can be used, and the power...
This circuit uses an optocoupler to obtain a solid state relay whose power depends on the Triac...
This power step for relay activation was found in the 1964 RCA transistors manual. The circuit is of the...