I am trying to create a digital clock, using 74ls90,74ls47
I have some question when trying to create 1 Hz square pulse
This picture is my teachers's simulation
I have searched on internet, and i known that i can use Ne555, or crystal, but i can't find any document about using NAND gate to create pulse
Anyone can help me explain that circuit ? And how i can choose value of resistor, capacitor ? (eg :R43 = 4k7, R44 = 1k, C3 = 100uF ..)
Sorry for my bad English
I have some question when trying to create 1 Hz square pulse
This picture is my teachers's simulation
I have searched on internet, and i known that i can use Ne555, or crystal, but i can't find any document about using NAND gate to create pulse
Anyone can help me explain that circuit ? And how i can choose value of resistor, capacitor ? (eg :R43 = 4k7, R44 = 1k, C3 = 100uF ..)
Sorry for my bad English