This circuit was found in an Electronic Design. It makes use of a relaxation oscillator to trigger an SCR and two relays. The circuit operates at frequencies of 12 to 180 cycles per minute.
This circuit is from an Electronics World of 1964. The circuit can be made with modern...
The Variable Frequency Oscillator (VFO) or Variable Frequency Oscillator shown in the figure can...
This guitar effect circuit was found in a 2002 documentation. The circuit can be powered by a 9 V...