Found in a 90s Popular Electronics, this circuit checks if a remote-control transmitter is emitting signals. The sensor is a general-purpose type found in many electronic devices.
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...