This adjustable frequency circuit was found in December 1986, Radio Electronics magazine. The base frequency is given by C1 and the power supply must be 5 V.
This circuit from the 90s, was found in an Electronic Design of the time. The components used are...
This circuit was found in an English technical documentation from 1973. The circuit generates...
The selected circuit was obtained in a Texas Instruments opto-electronics manual. The transistors can be...