This circuit was found in the September 1992 issue of Radio Electronics magazine. The circuit does not use a transistor to drive the relay and has no adjustments.
Wien Bridge This Vienna bridge oscillator generates a sinusoidal signal whose frequency depends...
This audio oscillator can also be frequency controlled by an LDR. The circuit is from a 1975...
In the 1992 publication, this amplifier is announced as having 400 W pmpo. Power transistors should...