Cheap 40KHz clock Electronic Circuit

From CircuitsArchive

Use a 40KHz Xtal and a 74C14 schmitt trigger:

             ________  <---------------- 2.2 M resistor
         ___|  2M2   |___
         |  |________|   |
         |               |
         |               |
         |     |\        |
         |     | \       |
         +-----|  O------+--------> Output 40KHz
         |     | /
         |     |/  gate 1 of 74C14
         |
         |
       --+--
        XXX   40KHz Xtal
       --+--
         |
         |
       -----
        ---
         -
 

This circuit has worked for me in many applications. (it might be an idea to buffer the signal befor using it. (There are still 5 unused gates in the 'C14.. :-)

Sources

• Sebastian Filzek