combining 4017 counters - extends their usefulness

extends their usefulness The well-known CMOS IC type 4017 is a decade counter which offers an excellent means of sequentially scan- ning small matrices. However, it may also be used as a programmable fre- quency devider. There are occasions when one counter or divider is not enough to provide the required function. One way of resolving this difficulty lies in combining a number of 4017s as shown in the accompanying diagram. The AND gates, N1, N3, . . together with inverters N2, N4, . . ensure that the output level at Q9 of each of the counters is retained at their own output terminal. The length of the counter/divider chain is determined simply by a jump con- nection (with S1 closed). When switch S1 is closed momentarily, the chain will cycle through just once if A is connected to pin 11 of ICn. The counter chain may also be used as the basis of a simple waveform generator. For that application the outputs of the counters are each ap- plied via different value resistors to the inv...