cascade 3 4017 counters

Hi,
I am having a problem in cascading 4017.
The Problem is that when the power is supplied to the circuit leds will be flashing upto the last one and after that repeating process of the leds to flash again is not happening.
Can anybody help me out on this..
Thanxx..
Fahad.

It is impossible to comment unless you post the circuit.

hi Len,
Its ok now,i have found the mistake and now the circuit is working fine,
Thank you for your Response,
Fahad

on1agg, your circuit image is clipped...

It's missing the top and the bottom

Hi purcer,

if you can live with 21 LEDs that circuit should be OK. You might connect up to 25 LEDs to it.

The switching sequence is like that:

1, 2, 3 up to 21 until all LEDs are lit, followed by a steady on for four count cycles, then extinguish and restart cycle.

The steady on state is achieved by using R-S FlipFlops.

With 21 LEDs the circuit uses quite a number of chips (total of 16) with two gates of the 4001 unused.

With the design you might either connect LEDs directly to the outputs (labelled 1 to 21) or use transistors for more LED current. If you use LEDs directly connected to the outputs I suggest using low current (2mA) LEDs.

Boncuk

Hi,
I have a similar problem,what did you do to solve this problem? please help me as soosn as possible....

mehdi_saadat said:

Hi,
I have a similar problem,what did you do to solve this problem? please help me as soosn as possible....

Click to expand...

hi,
Whats the nature of your 'similar' problem, ??? Cascading 4017's.??

The datasheet of a CD4017 from every American manufacturer shows how to cascade them.