This setting applies to virtually any photo transistor and any operational amplifier. The power supply must be symmetrical, and the gain is determined by the relationship between R2 and R1.
In the figure we have a simple signal tracer circuit to be coupled to the volume control of an AM...
This circuit was found in documentation from the 90s, using components from that time. The...
This circuit, obtained from old documentation, allows the recovery of sulfated batteries. The...