We found this circuit in a 1965 magazine. The circuit can be assembled with current equivalent transistors and the precision in generating the frequencies depends on the tolerance of the capacitors.
The circuit shown in the figure below is suggested by ON Semiconductor (www.onsemi.com), based on...
This control is intended for 110 VAC or 220 VAC Motors. Any TIC series triac can be used according the power...
This circuit was found in a 1999 English magazine, but can be easily assembled with BC548...