I'm trying to teach myself a little bit about op amps so I tried to build a simple comparator circuit to compare two pots and turn an LED on. I'm using a TS922 op amp I have lying around with a unipolar power supply. I've read about op amps on line and even have seen schematics, but I'm missing something.
Just as a starting point, if I clamp both - and + inputs to ground, I would expect that the output would be low (0). Is this correct? In my circuit, my LED shines merrily even with Vref and Vin grounded. My VCC is at 12V (my goal for the working voltages). Do I need to pull the output with a resistor? Put a bigger load on it?
My goal is to compare two pots. The specs on this op amp say the Vdiff between the inputs should be no more than 1V. So will I need to divide the input voltages further to limit them to 1V each at most?
I think I've reached the limit of my electronics knowledge, sadly. The op amp schematics for this sort of thing look so simple. In fact http://openbookproject.net/electricCircuits/Exper/EXP_6.html looks very similar to what I want to do, if my op amp is the right one for the job.
Any hints or pointers to better documentation and tutorials are greatly appreciated!
thanks,
Michael
Just as a starting point, if I clamp both - and + inputs to ground, I would expect that the output would be low (0). Is this correct? In my circuit, my LED shines merrily even with Vref and Vin grounded. My VCC is at 12V (my goal for the working voltages). Do I need to pull the output with a resistor? Put a bigger load on it?
My goal is to compare two pots. The specs on this op amp say the Vdiff between the inputs should be no more than 1V. So will I need to divide the input voltages further to limit them to 1V each at most?
I think I've reached the limit of my electronics knowledge, sadly. The op amp schematics for this sort of thing look so simple. In fact http://openbookproject.net/electricCircuits/Exper/EXP_6.html looks very similar to what I want to do, if my op amp is the right one for the job.
Any hints or pointers to better documentation and tutorials are greatly appreciated!
thanks,
Michael