This blocking oscillator configuration was found in a 1964 American book. The circuit can be designed with modern transistors and the frequency depends on the transformer.
This circuit measures alternating voltages on 5 scales and its accuracy depends on the tolerance of the...
This circuit was obtained in an American documentation translated in the 80's. The circuit can be...
Figure bellow shows another configuratíon for a Iow-frequency sine wave oscillator using CMOS...