How to clock a 2-bit binary counter using 555?

[installer2001]

The 555 timer will generate pulses which can be used to either:

1. Clock a 2-bit binary counter. The counter's output will be applied to the "select" inputs of a 2-to-4 decoder.

2. Clock a shift register with a circulating logic "1."

how this can be done how can i clock 2 bit binary counter
and how this can be applied to decoder
plz replyyy

 

[IanP]

Re: 555 reply required

1-bit binary counter is like dividing the iput signal by 2; 2-bit binary counter will add just another, identical stage and will divide the input signal by 2:2 =4 ..
You can buils a 2-bit binary counter using flip-flops, for example J-K or D ..
Here you will find an example of a 2-bit binary counter build around the D-type flip-flop (CD4013) ..
**broken link removed**
In the next stage, the outputs from the 2-bit binary counter can be connected to the A and B inputs of a 2-to-4 decoder, for example 74HC139:
http://www.fairchildsemi.com/pf/74/74VHC139.html ..

Regards,
IanP