Why are opamps and comparitors always drawn as an opamp on every schematic I see?
Never made much sense.
Because that's not an op amp schematic symbol. That is an amplifier schematic symbol and both comparators and op amps are amplifiers. A comparator is usually used as an open loop amplifier but
generally has a hysteresis feedback component (resistor etc)
Go back an look at the amplifier symbols from pre-op amp days. There is a + input and - (feedback)
input. In the op amp and comparator , they have been brought out to pins. In the early analog computer
days, (when analog computers were made using vacuum tubes, the amplifier symbol was basically the]
same only the triangle was slightly different. It had a + input and a - input.
See "Definition for the fledgling op amp" (second paragraph)
"The very first op amps weren't even called such, nor were they even called "Operational Amplifiers"
The naming of the device came after the war years (1947).
Op amp history/Black's Amplifier
ANALOG COMPUTERS
Typical electronic analog computers contain anywhere from a few to a hundred or more operational amplifiers ("op amps"), named because they perform mathematical operations
Mk-1 Fire Control Computer
The design of the post war Mark 1A may have been influenced by the Bell Labs Mark 8, Fire Control Computer which was developed as an all electrical computer, incorporating technology from the M9 gun data computer as a safeguard to ensure adequate supplies of fire control computers for the USN during WW2.[2] Surviving Mark 1 computers were upgraded to the Mark 1A standard after World War II ended. Digital fire control computers were not introduced until the age of minicomputers in the mid-1970s.
The Mk 8 computer used all electric methods of computation, in contrast to the Mk 1, which performed most computations via mechanical devices. The Mk 8 was found to be more accurate than the Mk 1 and substantially faster in reaching a fire control solution,[2] but by the time it was developed and tested in 1944, supplies of the Mk 1 were found to be sufficient in quantity.
First op amp
Differential Analyzer
There is really no way to distinguish between a generic feedback amplifier symbol and an op amp symbol as the
op amp symbol is the generic feedback amplifier symbol.
In short. There is no such thing as an op amp symbol.
It is simply a feedback amplifier symbol. Which brings us to the question of what would happen if you got your comparator chips and you op amp chips mixed up and tried to build an integrator using a comparator ?
So, if very little appears to be different in the schematic symbol or the internal workings, what is
the difference? The difference is in the output stage. An op amp has an output stage that is optimized for linear operation, while the output stage of a comparator is optimized for saturated operation.
Operational amplifiers (op amps) and comparators look similar; they even have very
similar schematic symbols. This leads a lot of designers to think they are interchangeable.
There is a strong temptation to use a spare section of a multiple op amp package as a
comparator to save money. This application note will explain why designers should not do
this.
comparator vs op amp
Now does it make sense ?