This circuit is from American documentation from the 1980s. The circuit can make use of any common NPN transistor and the power comes from two small batteries.
We found this circuit in an American publication from the 1990s. The triac must be equipped with a heat...
This TTL circuit uses LED indicators and must be powered by a voltage of 5 V. The capacitor...
This circuit uses an integrated CMOS having the frequency determined by the resistors and...