This simple neon lamp oscillator produces a 140 Hz, 40 V peak-to-peak signal. The frequency is given by the capacitor that can have its value changed. Note the high supply voltage.
Found on 80's Popular Electronics this circuit operates at 455 kHz. The explorer coil is formed by...
We find this circuit in a 2005 Linear Technology manual. The circuit applies to small DC motors...
This RF circuit measures transmission power from 0.25 W to 10 W. The maximum frequency depends on...