Pulse generator - adjusts the duty cycle in precise 1% steps

2 CLOCK Q¬? IL_ Q1 Jl__ _I1___FL IC1 Q9 QO J I Q1 I IC2 02 - 1 Q9 SET 013N3 R ESET08 N2 (90¬?- 54¬?) - 40%! pulse generator With the aid of this circuit, the duty 1 cycle of a signal may be adjusted very accurately in 1% steps within the 1% ... 99% range. At the same time, it is possible to keep the frequency of the output signal completely independent of the duty cycle setting. Accurate pulse generators are needed whenever a meter or a circuit that calculates the level of a signal on the basis of its duty cycle and evaluates and/or processes the signal to be calibrated. The type of circuits in mind are remote control (PPM) and phase cutoff angle meters. The pulse generator in figure 1 can be constructed quite easily using three CMOS ICs. The decimal counters IC1 and IC2 are connected as divide-by- tens. Flipflop N2/N3 is set via R1/C1 upon the falling edge of the Q9 signal of IC2 (which corresponds to the rising edge of 00!) and the Q output of the circuit goes high. The inte...