This circuit was found in a 1966 General Electric book. The triac and the day are from that time and can be replaced by modern equivalents depending on the load.
We find this circuit in an earlier American publication of 1978. The components are no longer...
Found in Radio Electronics from the 90's, this circuit employs a 3140 operational amplifier, still...
The circuit shown in figure 1 is a suggested application for ISL8107, a new integrated circuit from...