15. A certain counter has the state transition sequence 0->1->-2->-7 )> 6-> 4->5->3->0. The counter may be modified to provide a mod-5 count by jumping from state 5 to (1) state XXXXXXXXXXstate...

15. A certain counter has the state transition sequence 0->1->-2->-7 )> 6-> 4->5->3->0. The counter may be modified to provide a mod-5 count by jumping from state 5 to (1) state 2. (2) state 6. (3) state 0. {(4) state 7. 16. The 7490 is a mod-10 counter. What's the minimum number of such counters necessary to count to 85? flt; Not possible; count must be a multiplb of 10 '(2)2 (3) 3 - ' (4) 8 17. The repeating sequence of states for a panicular scaler is 0->1->2-> 3->4->5->0. The output pulse rate obtainable by monitoring state 4 (Hint: Fig. 10) zf(1) is the same as would be obtained by monitoring state 2. (2) is twice the rate obtained by monitoring state 2. (3) is one pulse every four triggers. (4) occurs two milliseconds after that obtainable by monitoring state 2. 18. The repeating sequence of a scaler is as given in problem 17. Outputs are obtained both from states 3 and 5. What's the trigger rate, in pulses per second, if the output signal from state 5 is to occur two milliseconds after that from state 3? (Hint: Count number of steps) (l) 500 pulses per second !(2) 1000 pulses per second I c I/ 2 (9) 1500 pulses per second 2 i:* (4) 2000 pulses per second ) n" r . ' o^v ) 19. The repeating sequence of a sSler is as given in problim 17. Outputs are obtained from both states 3 a/O S. What's the trigger rate, impulses per second, ifthe output signal f/m state 3 is to occur two milliseconds after that from state 5? (1) 500 pulses per second (2) 1000 pulses per second (3) 1500 pulses per second (4) 2000 pulses per second L ^ 2 J . .1 -) \*"P rdo- oln^ qc'iA i;l 0P 60 20. The counter whose repeating cycle is as described in problem 17 has three state-detector circuits to produce three output pulses-A" B, C. The trigger rate used is 1000 pulses'per second. The time interval between signals A and B is to be 1 millisecond; the time interval between signals B and C is to be 2 milliseconds. Which of the following sejs 6f three states would provide the proper timing intervals? (1) A=1,B=2,C=0 (2) A=1,B=2,C.=3 (3) A=l,B=2,C=4 # (4) A=1,B=2,C=5