Can anyone send me the simplest circuit of digital clock by using IC 74LS90-93, 74LS47 and 7 segment display to my email address "fhnaseer@yahoo.com", send it within one hour, I have to submit it to my teacher, it is a project for my semester, hurry up, within one hour,
Can anyone send me the simplest circuit of digital clock by using IC 74LS90-93, 74LS47 and 7 segment display to my email address "fhnaseer@yahoo.com", send it within one hour, I have to submit it to my teacher, it is a project for my semester, hurry up, within one hour,
nice schematic iyung w, looks interesting.
I just have some questions with your ckt.
1. What is the voltage input of this ckt?
2. Your 74LS47, 74LS08, 74LS32 and other ICs are not connected to Vdd. Do I have to connect it to Vdd and GND for it to work?
3. Does the 1MHz oscillator needs Vdd also for it to function?
For an accurate 60Hz timebase, you can use a 3.579545 MHz crystal with an MM5369, 8-pin IC with discrete components. Eliminate the ten-hour 7490 and 7447 with a 7474 D flip-flop and transistor wired as divide-by-two that is on from 10:00:00 to 12:59:59.
Out of curiosity, how would you set the time on this clock?
The MM5369 has not been made for many years. It needed a supply of at least 9V for its oscillator to work at the 3.58MHz crystal's frequency and its output current was much too low to drive old fashioned TTL. It was good in an accurate low power Cmos clock.
Hello everyone am new to here but am looking forward for a good project that am planning. I would like to build a digital clock. I saw a lot of schematics some of the schematics dont really explain it very well for me since am a newbie in this and still learning. I would really apriciate it if someone showed me step by step on how to do it am currently building something in multisim but am stuck. thats why i would like to start over with someone who could explain step by step thank you very much.
Here's mine. Works like a charm. 7490's with 7447's for the LEDs.
The daughter board is the bridge rectifier. I'm currently working on a new one. Same as the old, but has a better time setting circuit, and will be much smaller. The one that I build basically just uses switches to redirect the 1Hz time base into either the seconds, minutes, or hours sections.
The new clock is going to use a crystal so I don't have to bother with the 60 Hz line. I found a neat trick to get an easy, accurate 1 Hz time base for $6....
OK, before anyone blasts me with the "do your own work speech" let me let you that I'm 33, not in school, and this is a hobby. I already made a working 24 hour clock. (see attached pictures) It came out great. I even etched my own board.
I want to have a go at making a 12 hour version. Rev 2 of my clock will pretty much use the same board and chips (7490's and 7447s) I can get the clock to run in 12 hour mode, but the whole AM/PM LED is bothering me. I was going to add a flip-flop, but I can't for the life of me figure out how to get the LED to stay on when the hours read "12" and then off again 12 hours later.
Anyone have a schematic? I don't want to redo the clock using 7492s since I already have all the 7490s on hand.
I built a clock 14 years ago using 4000 series chips. I built it on breadboard and used it as my bedside clock for many years. Never got around to putting it in a proper case (as with a lot of the projects I used to build). It was probably one of the last things I built before abandoning hobby electronics until my resumption very recently.