The quadruple frequency circuit composed of CH7555

As shown in the figure, it is a quadruple frequency circuit. This circuit is a frequency multiplication circuit composed of three CH7555 timers. After the symmetrical square wave fi is input, it generates a double frequency through the inverter and transistor. This signal triggers the monostable circuit composed of CH7555 at the same time. Therefore, two groups of pulses with different widths are generated at the output ends of IC1 and IC2, and then their falling edges are used to trigger the monostable circuit composed of IC3, and the output end of IC3 obtains a quadruple frequency output.