These optical relays, which can act as a shield, were found in an American documentation from the 1980s. The circuit has a LDR sensor. It can be adapted for other types of sensors.
This circuit was found in an English magazine from 1979. The magazine no longer exists, but the...
This traditional TTL anti-clock setting was found in a 1993 American documentation. The circuit...
The astable multivibrator shown by the figure can produce signals in the 10 to 10 000 Hz band...