We found this configuration in a 1974 publication. Transistors can be replaced with equivalents such as 2N2222. The circuit has a dynamic range of 60 dB.
Found in Popular Electronics from the 90's, this circuit makes use of components from the time. |...
This circuit for the logic control of the 555 in a power supply was found in the October 1989...
In this circuit, a light-sensitive SCR or Light Activated SCR determines the operation of an...