im trying to understand a 555 chip to a 7474 dual d flip flop circuit.

why is the flip flop in (toggle mode) needed to produce a clock signal.

can the 555 not do this on its own!,

thanks,

 

If you need a 50% duty cycle clock, that may be the best way to do it. Otherwise, as you say, you don't need the FF. You can also use a CMOS 555 to get a pretty good 50% duty cycle, without the FF.