EXT. SYNC'ed 20 - LED Light Chaser / or phased Audio Gen. Clock

[RJSV]

    Two feature rich counter IC's are combined as a pair with 20 outputs. A 'RANGE' latch coordinates two CD-4017 Decade Counters, as low-high digits (oX and 1X).   A 20 LED 'Knight Rider' light chaser operates very similar to commonly seen circuits having ten outputs / LED's.

   An external RESET places the 20-step 'moving dot' circuit into phase (counter re-starts at zero count).

   For operating / clocking various audio waveform generators, a circuit input clock speed is set at 8800 hz,  to be divided down, before output as pulses / square waves, as connected by the CD-4017 sequencer outputs.   Don't forget,  the counter IC's are low power, and so better used with a transistor or other buffer for providing perhaps 5 mA,  more if you use an 'inverted' scheme (moving dark place, against all other LED's turned on.

Mistake on a gate:  That NAND gate shown (lower left corner of schematic), that mixes the EXT reset, that gate should be 'NOR',  as it mixes two -P signals.   Also,  looking above to the IC3b clock, the inverter should not be there, as want the end of each of the pulses, Q02 and Q12.
(that RANGE PREVIEW signal is used to de-glitch the two LED's on the Q0 outputs, as there can be a brief phantom flash, as waiting for the RANGE ff to toggle to proper range.)  thanks