Hi everyone
Could i use a op-amp(741) as a comparator to convert sine-wave to square-wave like this?
Hi everyone
Could i use a op-amp(741) as a comparator to convert sine-wave to square-wave like this?
Yes, but if -V is a negative voltage you can not wire it to an Arduino digital input pin.
Lefty
Yes, but if -V is a negative voltage you can not wire it to an Arduino digital input pin.
OH, I have a question
I got a wheel speed sensor, it generates AC
if it is connected like the above photo, what the +V and -V is connected respectively ?
+V to the Arduin power supply ? and -V ?
I am not quite sure about the op-amp comparator function...
Thanks a lot
f it is connected like the above photo, what the +V and -V is connected respectively
You connect the sensor to the ground and the op amp input. As it's AC it doesn't matter what way round it is.
ground to arduino ground.
Thanks mike
but, how to define the resistor value ?
Thanks
but, how to define the resistor value ?
It is just a voltage divider and the op amp has a high impedance so virtually any value from 1K to 1M will do.
Don't forget retroleftie's comments.
It is just a voltage divider and the op amp has a high impedance so virtually any value from 1K to 1M will do.
Don't forget retroleftie's comments.
the -V must be supplied in negative voltage ?
or he meant the output voltage could not be negative ?
He meant that the circuit as drawn will put negative voltages into the input of the arduino which will destroy it. Therefore you must put a series diode in line with the output, and something like a 1K pull down resistor on the arduino input you use.
oh
thanks
now i get it
but how could a get a -5V into the op-amp ?
but how could a get a -5V into the op-amp
Using the battery mentioned in a previous post. +ve of the battery to ground, -ve of the battery to the op amp.