This flasher or light pulsator can be used in an ordinary flashlight. The circuit can be adapted to use a lamp instead of an LED. Transistors support equivalents. C1 determines the frequency range.
This is the simulation of a Ultrasound Receiver using the 741 IC, an operational amplifier....
The resonant circuit depends on the crystal frequency that can go up to a few megahertz. The...
With this circuit it is possible to select the upper or lower side band on an SSB transmission by...