Can anyone help me to install counter to count down from 10 to 0 using 555 & 2 of 74192 & 2 of 7447 + 2 seven segment the problem I face is to make tens digit and unit digit as it counts from 10 to 0 so please if anyone can help me.
Sure, show us what you've got so far (schematic).Can anyone help me to install counter to count down from 10 to 0 using 555 & 2 of 74192 & 2 of 7447 + 2 seven segment the problem I face is to make tens digit and unit digit as it counts from 10 to 0 so please if anyone can help me.
Here is the Schematic I worked on the problems I face are:Sure, show us what you've got so far (schematic).
Homework? (why else use double decoder/driver/display for a single count more).
Thanks for the point of 9v vcc I search about type of my chips and it works in range from 4.5v to 5.5v for 7447 & from 2v to 6v for 74192 and from 4.5v to 16v for 555 so I deliver 5v to the all circuit not 9v and I connect CLR of both to ground then I test the circuit the result was the led indicator works well but the seven segment still fixed at 20 but there is something wired when I touch first 74192 the display shows various numbers then I remove my hand go back to 20 as it is , I don't know what is the problem note I replace the ics with another and have the same result .First of all, after looking at your circuit, the 74192's will not count unless the CLR inputs are tied low. Second, I do not know what type of chips you are using, but regular TTL chip must be powered from 5 volts not the 9 volts your circuit is showing. If you are using CMOS type chips then you will be OK. Third, you will need resistors between the outputs of the 7447 and your display. About 220 ohm should work. And last, I am not sure that your display type is correct, the 7447 puts out a logic high for each segment to be lit, and what I see from what you posted you have it wired that a logic low will light the segment. Will be gone for a while but will check back.
Mike
The point of 220 ohm it is only for saving 7 segment from damage and doesn't affect the circuit the problem I face why the circuit doesn't work ? what is the wrong ?Thanks for the point of 9v vcc I search about type of my chips and it works in range from 4.5v to 5.5v for 7447 & from 2v to 6v for 74192 and from 4.5v to 16v for 555 so I deliver 5v to the all circuit not 9v and I connect CLR of both to ground then I test the circuit the result was the led indicator works well but the seven segment still fixed at 20 but there is something wired when I touch first 74192 the display shows various numbers then I remove my hand go back to 20 as it is , I don't know what is the problem note I replace the ics with another and have the same result .
The second point I want it to count down from 10 and when reach 00 it reset what can I do to fix such problems.
First I am not angry & I am sorry for delivering bad impression about myself but I don't mean that.Where are you from Abdelrahman95. Update your profile and add your country.
Plus change R3 to 220Ω or 330Ω first.
Second find 4 pcs of 100nf ceramic capacitors. And connect 1 cap to each IC across the IC supply pins. Keep the capacitors as close to IC as possible.
1 cap for each IC..
Third do not apply more than 5V to the whole circuit and make sure you supply can handle atleast around 500mA.
Tell me are you using CA or CC 7 segments
This and your post #5 tells me that you're working on a solderless breadboard - you should check for loose connections and such and make sure you don't have long wires going everywhere. Nice and tidy is a must if you work on a crappy solderless breadboard with semi-bad contacts.Here is the Schematic I worked on the problems I face are:
First the seven segments display 20 or 22 I don't know why this specific numbers and it doesn't change.
Preload to the value 10 (0001) on the tens and (0000) on the units.Third I don't know how to make it reset when it reaches 00 ex: 10 09 08 07 06 05 04 03 02 01 00 reset 10 09 and so on .
I hope you can help me and correct me if I made mistakes.
It is not a home work. and thanks for explaining.You haven't answer the question, is this a homework?
We have homework forum here and the experts will like to help, if this is the homework, I will move it to the homework forum, and they will not doing the job for you directly, just hope you can learning something from discussion.
by Duane Benson
by Duane Benson