As suggested in another thread, I built this circuit which comes from an LM324AN datasheet. It uses a bipolar supply and takes a noninverting input of ½ Vcc as the reference via voltage division.
It was also suggested that with the single supply version of this circuit that the op-amp swings from 0v to Vcc using the ½ Vcc as the "center", but when the output is viewed with an oscilloscope the square wave has a positive and negative component (of nearly equal amplitude and time period), yet the image of the circuit shows the low as 0 and not -V.
I've been pondering this circuit for some time in an effort to get a solid mental image of all its stages and I seem to be stuck on the point regarding the negative voltage output cycle.
Any explanation would be helpful.
Thank you,
Charles