This circuit produces the sound of a motorcycle or an outboard motor. The frequency is adjusted in the pot. For supplies above 9 V the BD136 must be equipped with a small heat sink.
Found in American documentation from the 90s, this circuit has the signal frequency determined by...
This simple circuit detects when a conductive liquid reaches the sensors. The circuit has no...
This circuit appears elsewhere in this section. This version is from General Electric from the...