This circuit was found in the February 1990 issue of Radio Electronics magazine. The gain is given by the capacitors according to the table next to the diagram.
This interesting constant current source circuit was found in the September 1989 issue of Radio...
We find this circuit in a 1970 publication. Transistors can be replaced by current equivalents and LDR is...
Employing a unijunction and a triac of the era, this 1964 Electronic Design circuit uses a diac to...