We found this circuit in the August 1994 issue of Electronics Now magazine. The circuit is based on the now uncommon CMOS 4046. The frequency range is given by C1.
This source, from a 1982 documentation, uses a triac to control the power and voltage applied to...
This circuit was found in Motorola documentation from 1968, using high power transistors and...
This circuit was found in documentation from the 1980s. The circuit uses several components of the...