How to build Knightrider lights for model cars

This simple circuit drives 6 LEDs in 'Knightrider scanner mode'. Power consumption depends mainly on the type of LEDs used if you use a 7555 (555 CMOS version).

Circuit diagram

Note that VDD and GND for the ICs are not shown in the circuit drawing.

Pin-outs:
(7)555
1 GND
2 TRIGGER
3 OUTPUT
4 RESET
5 CONTROL VOLTAGE
6 THRESHOLD
7 DISCHARGE
8 VDD

4017
1 Q5
2 Q1
3 Q0
4 Q2
5 Q6
6 Q7
7 Q3
8 GND
9 Q8
10 Q4
11 Q9
12 CO
13 NOT ENABLE
14 CLK
15 RESET
16 VDD