When we want to a voltage comparator circuit as well, accurate cheap and easy to use. Usually we choose to use LM741, it is op-amp is very versatile in use. It was not designed for this particular work. So low efficiency. should use IC specific work better. Same price and easier to use. A LM339 is selected.
The LM339 is a package of four comparators.
The comparator is an op-amp designed to run at its maximum gain.
So that the output is either fully ON or fully OFF.
It can be powered by a battery or other single-polarity supply over a very wide voltage range.
All four comparators are installed in a single 14-pin package. same LM324 Quad OP-AMP in the previous.
The LM339 has many applications.
-The power supply voltage range are +2 voltage to +36 volts.
-The power supply current is 0.8 milliamperes.
-The output current (positive supply to output) are 16 milli amperes typical (6 mA minimum).
-Maximum voltage gain (typical) are 200,000 (50,000 minimum).
-No feedback resistor necessary.
-Response time for switching requirement ( in typical): 1.3 microseconds (uS).
Other circuits are recommended.