Digital clock with setting function / Siti Kartini Hamzah and Norzaima Ibrahim

The digital clock with setting function has three units circuit: power supply unit, digital clock unit and display unit. To operate the digital clock, we use voltage from power supply that had been regulated by voltage regulator 7805.
In this project , concentration are given for digital clock unit and display unit only. Timer 555 is used as a clock oscillator to produce pulses. Then decade counter, 7490 and 7092 are used to count he pulses. BCD to seven segment code, 7447 are used to convert the 4 it BCD code into a seven segment code at the display. All the display are common anode and indicates time between 00.00 to 23.59 hours. Switches are used for setting the desired time