rectangular pulse generator

The excellent properties of counter/divider IC type 4059 have, so far, not been given the prominence in Elektor they deserve. One of these properties is the provision of divide ratios anywhere between 3 and 15 999 depending on the logic level at inputs J1...J16 and the setting of switches S 19. The 4059 is clocked by a relaxation oscillator, N1-N2, which could have been a crystal-controlled type instead of the one shown in figure 1. The dual-D bistable type 4013 at the output is essential because the width of the pulses at pin 23 of the 4059 is comparable to the clock frequency. The bistable ensures that the pulses emanating from pin 23 are reshaped into rectangular form. The Q output of the bistable is, of course, half the fre- quency of the wave train at pin 23 of the divider. 1 TD TC ∎ 014■ TA 7-52 14 C1 IC1 9 10 15 16 17 18 19 20 21 22 6 5 4 3 R1 IC2 IC3 Ka Kb 100p 16V 0 4059 K J1 121 2 JI J4 J5- -J8 J9 J12 J 3 J16 s16 s9 R16 1; 1 R9 R8 R1 ... R16 = 16 x 100 k .1= LE Input...