a comparator is a device that compares two voltages or currents and outputs a digital signal indicating which is larger.
this op amp takes two voltages 9v or 6v and
outputs either 5v or 0v
output is high if + > -
output is low if - > +
output is low if + = -
use the switches to redirect the inputs to the comparator
interestingly I found that if I removed the volt meter the circuit failed a 10k resistor fixed that
this hopefully will become a component in my to be built 555 circuit
