I'm so close to getting a project complete......I'm counting frequency with BCD and driving a segment display with a 4510 counter and 4511 decoder now...switching my plan from 7493, 7475 and 7447......anyways...I'm using a 555 timer in which its output is the CLK IN fro my 4510........my question is......for our final, were using a 120 VAC / 12.6 Stepdown Transformer which is 60 Hz....now if I tie that in to a 741 Op Amp, what input pin for my 555 is coming from the out from the 741?

 

Standard starting query #1... Schematic please?