hi, can you please help and tell me the application of this led chaser : http://www.google.rw/imgres?imgurl=...OvT5_jFI-c-wbT6sDTCA&ved=0CGQQ9QEwBA&dur=2841
and where it can be used and what is this resistor :1k is doing in it.

 

This is the complete schematic. The purpose is to entertain, teach electronic theory and circuit construction techniques. Sometimes a sequencer like this is used to control synthesized sound effects.

The purpose of the 1k resistor is described in the text below the schematic.

http://www.qrp.pops.net/LEDs.asp

 

The base application is it looks cool. It is visually stimulating.