This circuit for the 3 to 6 MHz band was found in a 90s Popular Electronics. The components of the network formed by C6 depend on the frequency range to be covered.
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...