internal schematic: note the number of transistors
are integrated chip based amplifiers that can be used for a variety of
functions such as amplification, comparing, switching and other tasks.
build an amplifier circuit from many components when you can use an off
the shelf OP amp package with reliable results and economical pricing?
The LM 386 OP amp chip can
easily be configured into a
Schematic of GFI Circuit
A GFI uses an OP amp to compare
voltages from a small current transformer
to detect small potentially harmful currents
leaking to ground and initiating tripping
of the circuit