Created April 30, 2010
Latest Update: July 29, 2011


This is a circuit for a 25 LED Chaser. (Or possibly More.)
And a Circuit board for the main electronics of it.

Sorry, No PCB for the LED's as everyone will want different physical layouts.

This Circuit can also be Expanded to more LED's by adding more middle sections.
But it will than require a different PCB layout.

Additionally, by Changing the Connection point of the trace on pin 15 of the
first 4017 that goes to pin 11 of the last 4017, you can Reduce the LED Count.



Example: Cut trace at Pin 11 and connect it to Pin 10.
It will now sequence 20 LED's
(And Do Not use the Last 5 LED's at all.)



The Speed trimpot will allow for some variation in Speed, but you can
also change the Resistor and/or Capacitor to get faster or slower rates.

All LED's Negatives are a connection to the "COM" pad, than through a
220 Ohm resistor to Ground. No Need for other "current limiting"
resistors, even with supply voltages up to 16 volts.)





"The Latest Revised Schematic for this Chaser.


"The Circuit Board".
This REVISED PCB has been built & tested and it works good.


"Picture Overlay of Assembled board".
Also showing the wires to the LED's.
NOTE: This PCB is Slightly Different from the New PCB Above.
(There is No "100 Ohm Resistor", and LED's Connect to "COM" pad,
than through a 220 ohm resistor to Ground.)



"A SHORT Video Clip".
Circuit in Operation








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 Chemelec 
 *Copyright © 2010 & 2011*