Light chaser part two.
Hi Purser,
I actually designed this circuit a couple of months ago, it was originally
intended to replace an obsolete IC in an antique calculator.
( The 1820-1223 cathode driver in an old hp 35 calculator.)
I had never tested this circuit because I was waiting for the description
and the schematic of this calculator but your circuit was so similar to my
original design that I decided to add an extra 4017 and build it.
Altough the circuit worked fine the addition of the third 4017 caused some
problems. ( The second and the third 4017 did exactly the same !) So I had
to add an extra gate to make it work the way it should, this extra gate was
made from the two 1N4148's and the 10k resistor. At this stage I should have
taken it back to the drawing board but I was too busy designing and testing
other circuits. But the circuit works fine the way it is so we'll add two or
even more 4017's.
The far left part is the first counting section and the far right is the last.
The one in the middle is the one you should duplicate a number of times to
drive the amount of leds you want, the more the better.
Have much fun !
on1aag.