We found this circuit in a 1996 publication. Equivalent components can be tried, especially in the case of the photodiode. The circuit is powered by a 12 V source.
Found in Popular Electronics from the 90's, this circuit uses common components and can be easily...
This circuit was found in a 1973 publication. The SCR may be the TIC106 and must use a heat sink,...
This circuit was obtained from my Mechatronics Sourcebook, published in the United States. In it...