This circuit doubles the frequency of signals from 10 to 50 MHz. We found it in a 1969 Electronic Design. The components are from the period.
This circuit activates a relay when the sensor receives light. The sensor can be any common LDR,...
We found this circuit in a 1980 documentation. With basic changes, including transistors that were...
When a small air current reaches the piezoelectric sensor, a small audio signal is generated and...