This additional bell circuit was found in the February 1994 Electronics Now magazine. The transistors are common, and the circuit is for analog lines.
This application of the RCA integrated circuit released at the time was found in the August 1970...
This circuit indicates the logical level of a CMOS circuit, extracting the power from the circuit...
In this amplifier, the supply voltage is 35 V and the input resistance is 2k2. Equivalent...