This RF preamplifier for the 450 MHz band was found in an amateur radio documentation from the 1980s. The transistor supports an equivalent operating at the recommended frequency.
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...