Found in a Popular Electronics from the 90s, this circuit generates signals from 2 Hz to 30 kHz in different bands. The circuit can be powered by voltages from 5 to 12 V, depending on the application.
With this circuit, a relay can be activated from an alternating signal with frequency up to a few...
With this circuit the visually impaired can easily locate important places inside the house, such...
In the figure we have the way to use the transistors of an old-paired pair as a trigger circuit. The...