Frequency Counter: Divider Schematic
The divider design is pretty self-explanatory. One can choose between division by 1, 10 or 100 or no output (tied low) using the CONTROL input connected to the analog multiplexer HC4052. AC04are used to drive 3 indication LEDs as well as to buffer the signal. A single HC390 includes 2 divider by 2 and 5 which can be combined as 2 dividers by 10.