Using the CMOS IC 4046 we found this VCO in the November 1984 Radio Electronics magazine. The center frequency is given by the capacitor. The maximum frequency is around a few megahertz.
This circuit controls a relay in a bistable way by touching the sensors type NF (CH3) and NO...
This circuit produces modulated tones in a loudspeaker. The effects can be adjusted by the...
This is a simulation of a Relaxation Oscillator using a programmable unijunction transistor (PUT). The...