johnson counter

Thread Starter

bian momani

Joined Feb 22, 2010
6
hi
how to Design Johnson counter using 74ls191,74ls194,JK flip flop,and other component if needed.????????????????????????????????
 

Papabravo

Joined Feb 24, 2006
16,938
hi
this link not help me ...........thanx any way
I don't understand. Was there something wrong with the link?
You start with a shift register, and an inverter. Take the output of the most significant stage and route it back to the shift register input through the inverter. Reset the shift register to all ones or all zeros. Now each time you clock the shift register you will see either ones or zeros walking through the shift register.
 

Ron H

Joined Apr 14, 2005
7,014
I don't understand. Was there something wrong with the link?
You start with a shift register, and an inverter. Take the output of the most significant stage and route it back to the shift register input through the inverter. Reset the shift register to all ones or all zeros. Now each time you clock the shift register you will see either ones or zeros walking through the shift register.
Of course, there's also that little circuit (the NOR gates in the 4017) that gets it into the correct sequence if it should find itself in one of the "short cycle" states. All Johnson counters with 3 or more stages need that function.
 
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