This elaborate mixer is from an Electronics Today International from the 80s. Operational amplifiers are common and resistors with no value determine the gain of the amplification steps.
This circuit was indicated in an old American publication to serve as a Laser alarm system as a...
To control direct current loads, under voltages between 12 and 200 V, and currents up to 3 A, we...
The purpose of this circuit is to keep the courtesy light of a car on for an additional time given...