Comparator circuit

Comparator

Thanks to all.

I check/try some of the suggestion and got this circuit to work as I expected. I add the output of a piezodisc to pin 5 and the reference to pin 4. I used the "pull up" idea for the output and it work.When I hit the piezo disc the LED is turn on. My next step is to interface the output to a 4066 bilateral switch. Can I connect the 4066 to the output of pin 2 ? Will it turn on the bilateral switch?

Again thanks a lot for your help.

If your diode is actually an LED (It should have arrows for the light beam) then you show it upside down.
The LED limits the output voltage from the comparator so it is too low to activate a CD4066 bilateral switch.

Remove the LED then the output voltage from pin 2 is fine to activate the CD4066 if it also has a supply voltage of only 5V, and drive a transistor that can turn on the LED though a current-limiting resistor.

Comparator

Thanks Audioguru for the correction on the LED and thanks for the information on how to connect the 4066 bilateral switch.

Again thanks to all.